Merge pull request 'Add PHPUnit test suite — 222 tests, 100% code coverage' (#1) from Lyra into main

First AI contribution to main branch, a full suite of tests, thank you GLM-5.2.

.env.test

@@ -0,0 +1,27 @@
+APP_ENV=test
+APP_DEBUG=0
+APP_SECRET=test_secret_key_change_me
+# fixed TOTP secret (JBSWY3DPEHPK3PXP) so functional tests can compute valid codes
+TOTP_URI='otpauth://totp/Test-TOTP?secret=JBSWY3DPEHPK3PXP'
+COOKIE_TTL=2592000
+SUBDOMAIN_REDIRECT=0
+AUTH_SUBDOMAIN=''
+IP_TTL=0
+TEAPOT=1
+BURST_COUNT=10
+BURST_TIME=30
+UPPER_COUNT=100
+UPPER_TIME=3600
+TITLE='Pre-Authentication System'
+BG_COLOR='#029386'
+FG_COLOR='#ffffff'
+ERROR_COLOR='#ffb16d'
+ID_NAME='Session ID'
+TOKEN_NAME='Authentication Token'
+SUBMIT_NAME='Submit'
+ERROR_MESSAGE='Unsuccessful login attempt'
+TEAPOT_TITLE="I'm a teapot"
+TEAPOT_MESSAGE='I refuse to brew coffee'
+TOO_MANY_TITLE='Too many requests'
+TOO_MANY_MESSAGE='Try again later'
+SHELL_VERBOSITY=0

.gitea/workflows/develop.yaml

@@ -0,0 +1,34 @@
+name: Push Develop
+
+on:
+  push:
+    branches:
+      - 'main'
+      - 'develop'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          platforms: linux/amd64,linux/arm64
+          tags: |
+            ${{ vars.DOCKERHUB_TARGET }}:develop
+

.gitea/workflows/docker.yaml

@@ -0,0 +1,34 @@
+name: Push Docker
+
+on:
+  push:
+    tags:
+      - '*.*.*'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          platforms: linux/amd64,linux/arm64
+          tags: |
+            ${{ vars.DOCKERHUB_TARGET }}:latest
+            ${{ vars.DOCKERHUB_TARGET }}:${{ github.ref_name }}
+

.gitea/workflows/publish.yaml

@@ -0,0 +1,37 @@
+name: Sync GitHub
+
+on:
+  push:
+    branches:
+      - '**'
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Configure Git
+        run: |
+          git config --global user.name "Andrew Sync"
+          git config --global user.email "sync@digitaladapt.com"
+
+      - name: Add GitHub Remote
+        env:
+          SYNC_TOKEN: ${{ secrets.SYNC_GITHUB_TOKEN }}
+          SYNC_TARGET: ${{ vars.SYNC_GITHUB_TARGET }}
+        run: |
+          git remote add github "https://digitaladapt:${SYNC_TOKEN}@github.com/$SYNC_TARGET"
+
+      - name: Push Current Branch
+        run: |
+          git push github HEAD:${GITHUB_REF_NAME}
+
+      - name: Push Tags
+        run: |
+          git push github --tags
+

.gitea/workflows/tests.yaml

@@ -0,0 +1,33 @@
+name: Tests
+
+on:
+  push:
+    branches:
+      - 'main'
+      - 'develop'
+  pull_request:
+    branches:
+      - 'main'
+      - 'develop'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.5'
+          extensions: apcu, mbstring
+          coverage: xdebug
+          ini-values: apc.enable_cli=1
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress
+
+      - name: Run tests
+        run: XDEBUG_MODE=coverage vendor/bin/phpunit --coverage-text

.gitignore

@@ -1,4 +1,4 @@
-
+/.idea/
 ###> symfony/framework-bundle ###
 /config/secrets/prod/prod.decrypt.private.php
 /public/bundles/
@@ -6,3 +6,9 @@
 /vendor/
 ###< symfony/framework-bundle ###
 
+
+###> phpunit/phpunit ###
+/phpunit.xml
+/.phpunit.cache/
+/bin/.phpunit.result.cache
+###< phpunit/phpunit ###

Dockerfile

@@ -1,5 +1,5 @@
 # use build image, to simplify final image
-FROM php:8.4-trixie AS build
+FROM php:8.5-trixie AS build
 
 # install APCu and composer
 RUN pecl install apcu && \
@@ -31,7 +31,7 @@ RUN composer install --no-dev --optimize-autoloader
 RUN composer dump-env prod --empty
 
 # start creating final image
-FROM dunglas/frankenphp:php8.4-trixie
+FROM dunglas/frankenphp:php8.5-trixie
 
 # install APCu
 RUN pecl install apcu && \
@@ -51,6 +51,8 @@ COPY --from=build /app /app
 COPY ./Caddyfile /etc/frankenphp/Caddyfile
 RUN cp $PHP_INI_DIR/php.ini-production $PHP_INI_DIR/php.ini
 RUN echo 'expose_php = off' > $PHP_INI_DIR/conf.d/restrict.ini
+# console needs apc to manage cache
+RUN echo 'apc.enable_cli = on' > $PHP_INI_DIR/conf.d/console.ini
 
 # app uses var folder for cache storage
 VOLUME ["/config", "/data"]

bin/phpunit

@@ -0,0 +1,4 @@
+#!/usr/bin/env php
+<?php
+
+require dirname(__DIR__).'/vendor/phpunit/phpunit/phpunit';

composer.json

@@ -1,18 +1,18 @@
 {
     "type": "project",
-    "license": "proprietary",
+    "license": "MIT",
     "minimum-stability": "stable",
     "prefer-stable": true,
     "require": {
-        "php": ">=8.2",
+        "php": ">=8.4",
         "ext-ctype": "*",
         "ext-iconv": "*",
-        "bacon/bacon-qr-code": "^3.0.3",
-        "runtime/frankenphp-symfony": "^0.2.0",
+        "bacon/bacon-qr-code": "^3.1.1",
+        "runtime/frankenphp-symfony": "^1.0.0",
         "spomky-labs/otphp": "^11.4.2",
         "symfony/cache": "7.4.*",
         "symfony/console": "7.4.*",
-        "symfony/flex": "^2.10",
+        "symfony/flex": "^2.11",
         "symfony/framework-bundle": "7.4.*",
         "symfony/mime": "7.4.*",
         "symfony/rate-limiter": "7.4.*",
@@ -35,6 +35,11 @@
             "App\\": "src/"
         }
     },
+    "autoload-dev": {
+        "psr-4": {
+            "App\\Tests\\": "tests/"
+        }
+    },
     "replace": {
         "symfony/polyfill-ctype": "*",
         "symfony/polyfill-iconv": "*",
@@ -68,5 +73,10 @@
             "allow-contrib": false,
             "require": "7.4.*"
         }
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^13.2",
+        "symfony/browser-kit": "7.4.*",
+        "symfony/css-selector": "7.4.*"
     }
 }

config/packages/test/cache.yaml

@@ -0,0 +1,12 @@
+framework:
+    cache:
+        app: cache.adapter.array
+        pools:
+            nonceCache:
+                adapters: cache.adapter.array
+            rateLimitCache:
+                adapters: cache.adapter.array
+            sessionCache:
+                adapters: cache.adapter.array
+            sessionStorage:
+                adapters: cache.adapter.array

config/packages/test/framework.yaml

@@ -0,0 +1,4 @@
+framework:
+    test: true
+    session:
+        storage_factory_id: session.storage.factory.mock_file

config/packages/twig.yaml

@@ -7,16 +7,12 @@ twig:
             bg_color: '%env(BG_COLOR)%'
             fg_color: '%env(FG_COLOR)%'
             error_color: '%env(ERROR_COLOR)%'
-            return_field: '%env(QUERY_PREFIX)%return'
-            id_field: '%env(QUERY_PREFIX)%id'
-            token_field: '%env(QUERY_PREFIX)%token'
-            password_field: '%env(QUERY_PREFIX)%password'
             id_name: '%env(ID_NAME)%'
             token_name: '%env(TOKEN_NAME)%'
-            password_name: '%env(PASSWORD_NAME)%'
             submit_name: '%env(SUBMIT_NAME)%'
             error_message: '%env(ERROR_MESSAGE)%'
             teapot_title: '%env(TEAPOT_TITLE)%'
             teapot_message: '%env(TEAPOT_MESSAGE)%'
             too_many_title: '%env(TOO_MANY_TITLE)%'
             too_many_message: '%env(TOO_MANY_MESSAGE)%'
+            debug: '%env(SHELL_VERBOSITY)%'

config/services.yaml

@@ -8,37 +8,40 @@
 # https://symfony.com/doc/current/best_practices.html
 #   #use-parameters-for-application-configuration
 parameters:
-    # --- main variables ---
+    # --- main options ---
     # URI containing secret and config for TOTP, which determines the token to login
     # app will generate one, if not provided, but you should copy it to your .env file
     # format: "otpauth://totp/<label>?secret=<secret-key>"
     env(TOTP_URI): ''               # blank to have the app generate one at random
     # how long will someone stay logged in, measured in seconds, zero for DEFAULT
     env(COOKIE_TTL): '2592000'      # default 30 days
-    # rate limiting can *NOT* be disabled, but you could allow hundreds of logins a second
-    # default is the lower of 2 per half-minute or 10 per hour
-    env(BURST_COUNT): 2   # 2 per 30 seconds
-    env(BURST_TIME): 30   # seconds
-    env(UPPER_COUNT): 10  # 10 per hour
-    env(UPPER_TIME): 3600 # seconds (1 hour)
+    # Enable optional redirection to a dedicated authentication subdomain
+    env(SUBDOMAIN_REDIRECT): '0' # boolean, 1 to enable
+    # The subdomain (e.g., auth.example.com) to which unauthenticated users are redirected
+    env(AUTH_SUBDOMAIN): ''
 
-    # --- extra variables ---
-    # query parameter prefix to prevent collisions
-    env(QUERY_PREFIX): '_preauth_'
+    # --- extra options ---
     # how long do we allow all traffic from an ip address after successful login
     # could be useful if you have a system which does not handle cookies
     env(IP_TTL): '0'                # default disabled, time in seconds
     # once blocked, do we respond with "I'm a teapot", false to use "Too many requests"
     env(TEAPOT): '1' # boolean
 
-    # --- styling variables ---
+    # --- rate limiting ---
+    # Note: rate limiting can *NOT* be disabled, but you could allow hundreds of logins a second
+    # rate limiting, default is the lower of 2 per 30 seconds or 10 per hour
+    env(BURST_COUNT): 2             # 2 per 30 seconds
+    env(BURST_TIME): 30             # seconds
+    env(UPPER_COUNT): 10            # 10 per hour
+    env(UPPER_TIME): 3600           # seconds (1 hour)
+
+    # --- styling options ---
     env(TITLE): 'Pre-Authentication System'
-    env(BG_COLOR): '#029386'
-    env(FG_COLOR): '#ffffff'
-    env(ERROR_COLOR): '#ffb16d'
+    env(BG_COLOR): '#029386'        # teal
+    env(FG_COLOR): '#ffffff'        # white
+    env(ERROR_COLOR): '#ffb16d'     # apricot (light orange)
     env(ID_NAME): 'Session ID'
     env(TOKEN_NAME): 'Authentication Token'
-    env(PASSWORD_NAME): 'Authentication Password'
     env(SUBMIT_NAME): 'Submit'
     env(ERROR_MESSAGE): 'Unsuccessful login attempt'
     # title and message to use on block page, if teapot is true
@@ -48,9 +51,14 @@ parameters:
     env(TOO_MANY_TITLE): 'Too many requests'
     env(TOO_MANY_MESSAGE): 'Try again later'
 
-    app.cookie_ttl: '%env(COOKIE_TTL)%'
-    app.query_prefix: '%env(QUERY_PREFIX)%'
+    # --- debug options ---
+    env(SHELL_VERBOSITY): '0'       # set to 3 to log debug
+
+    # --- application variables ---
     app.totp_uri: '%env(TOTP_URI)%'
+    app.cookie_ttl: '%env(COOKIE_TTL)%'
+    app.subdomain_redirect: '%env(SUBDOMAIN_REDIRECT)%'
+    app.auth_subdomain: '%env(AUTH_SUBDOMAIN)%'
 
     app.ip_ttl: '%env(IP_TTL)%'
     app.teapot: '%env(TEAPOT)%'

docs/Caddyfile

@@ -1,33 +1,28 @@
-# if using caddy v2.9.x+ you can use this snippet
-# snippet to put the preauth system in front any service easily
-(preauth) {
-	# make sure caddy and preauth are on the same network
-	reverse_proxy {args[0]} preauth {
-		# leave body content for protected service
-		method GET
-		# if auth is successful, send request to protected service
-		@preauth_ok status 2xx
-		handle_response @preauth_ok {
-			{block}
-		}
-	}
-}
-
-# example of securing full subdomain
-# TODO replace domain and service name
+# example of securing full service
+# TODO replace domain and service name and port
 service.example.com {
-	import preauth * {
-		reverse_proxy service_container
+	forward_auth preauth {
+		uri {uri}
+		copy_headers Remote-User
 	}
+	reverse_proxy service-container:80
 }
 
-# you can only lock down only select paths
-# or any other match criteria, if desired
-# https://protected.example.com/secure/
+# you can choose to only restrict select paths
+# or any other Caddy match criteria, if desired
+# IE: https://protected.example.com/secure/
 protected.example.com {
-	import preauth /secure/* {
-		reverse_proxy protected-service:9000
+	# note any request that does not start with "/secure/" is NOT protected
+	forward_auth /secure/* preauth {
+		uri {uri}
+		copy_headers Remote-User
 	}
-	reverse_proxy exposed-service:9000
+	reverse_proxy protected-service:9000
 }
 
+# optionally, if you want to use a subdomain for centeral preauth
+# set SUBDOMAIN_REDIRECT to true
+# and AUTH_SUBDOMAIN to match the subdomain you use here
+auth.example.com {
+	reverse_proxy preauth
+}

docs/compose.yaml

@@ -1,7 +1,7 @@
 services:
   preauth:
     env_file:
-      # TODO rename "env.example" to ".env", edit as needed
+      # TODO rename "example.env" to ".env", edit as needed
       # strongly recommend setting TOTP_URI, if not provided the app
       # will generate one for you, please copy it into your .env file
       - .env
@@ -10,10 +10,7 @@ services:
     image: digitaladapt/preauth:latest
     restart: unless-stopped
     # if you wish to set the user, you must make sure that the user
-    # can write to /app/var/ within the container, and that all files
-    # and folders within are writable as well
-    # IE: `$chown -R <uid>:<gid> /path/to/volume/of/app/var`
-    #
+    # can write to /config and /data within the container
     #user: <uid>:<gid>
     volumes:
       - preauth-config:/config

docs/example.env

@@ -1,4 +1,4 @@
-# --- Main Options ---
+# --- main options ---
 
 # URI containing secret and config for TOTP, which determines the token to login
 # app will generate one, if not provided, but you should copy it to your .env file
@@ -8,16 +8,14 @@
 # how long will someone stay logged in, measured in seconds, zero for DEFAULT
 #COOKIE_TTL=2592000         # default 30 days
 
-# NOTE: rate limiting can *NOT* be disabled,
-# but you could allow hundreds of logins a second
+# we can use a central auth, so that users only need to login once to have access to
+# multiple services. Requires using sub-domains under the same domain.
+# IE: if enabled have "service-one.example.com" redirect "auth.example.com", and after
+# successful auth, user can visit "service-two.example.com" without having to login again.
+#SUBDOMAIN_REDIRECT=false   # default disabled, boolean
+#AUTH_SUBDOMAIN=''          # blank, hostname we send user to, to see login page
 
-# rate limiting, default is the lower of 2 per 30 seconds or 10 per hour
-#BURST_COUNT=2   # 2 per 30 seconds
-#BURST_TIME=30   # seconds
-#UPPER_COUNT=10  # 10 per hour
-#UPPER_TIME=3600 # seconds (1 hour)
-
-# --- Extra Options ---
+# --- extra options ---
 
 # how long do we allow *ALL* traffic from an ip address after successful login
 # could be useful if you have a system which does not handle cookies
@@ -26,14 +24,23 @@
 # once blocked, do we respond with "I'm a teapot", false to use "Too many requests"
 #TEAPOT=true                # default enabled, boolean
 
-# --- Styling Options ---
+# --- rate limiting ---
+
+# Note: rate limiting can *NOT* be disabled, but you could allow hundreds of logins a second
+# rate limiting, default is the lower of 2 per 30 seconds or 10 per hour
+#BURST_COUNT=2              # 2 per 30 seconds
+#BURST_TIME=30              # seconds
+#UPPER_COUNT=10             # 10 per hour
+#UPPER_TIME=3600            # seconds (1 hour)
+
+# --- styling options ---
+
 #TITLE='Pre-Authentication System'
 #BG_COLOR='#029386'         # teal
 #FG_COLOR='#ffffff'         # white
 #ERROR_COLOR='#ffb16d'      # apricot (light orange)
 #ID_NAME='Session ID'
 #TOKEN_NAME='Authentication Token'
-PASSWORD_NAME='Authentication Password'
 #SUBMIT_NAME='Submit'
 #ERROR_MESSAGE='Unsuccessful login attempt'
 # title and message to use on block page, if teapot is true
@@ -43,3 +50,6 @@ PASSWORD_NAME='Authentication Password'
 #TOO_MANY_TITLE='Too many requests'
 #TOO_MANY_MESSAGE='Try again later'
 
+# --- debug options ---
+#SHELL_VERBOSITY=0          # set to "3" to log debug
+

phpunit.dist.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!-- https://phpunit.readthedocs.io/en/latest/configuration.html -->
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
+         colors="true"
+         failOnDeprecation="true"
+         failOnNotice="true"
+         failOnWarning="true"
+         bootstrap="tests/bootstrap.php"
+         cacheDirectory=".phpunit.cache"
+>
+    <php>
+        <ini name="display_errors" value="1" />
+        <ini name="error_reporting" value="-1" />
+        <server name="APP_ENV" value="test" force="true" />
+        <server name="SHELL_VERBOSITY" value="-1" />
+        <server name="KERNEL_CLASS" value="App\Tests\TestKernel" />
+        <!-- fixed TOTP secret so functional tests can compute valid codes -->
+        <server name="TOTP_URI" value="otpauth://totp/Test-TOTP?secret=JBSWY3DPEHPK3PXP" />
+        <server name="APP_SECRET" value="test_secret_key_change_me" />
+        <!-- high rate limits so functional tests don't get blocked -->
+        <server name="BURST_COUNT" value="10000" />
+        <server name="UPPER_COUNT" value="10000" />
+    </php>
+
+    <testsuites>
+        <testsuite name="Project Test Suite">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <source ignoreSuppressionOfDeprecations="true"
+            ignoreIndirectDeprecations="true"
+            restrictNotices="true"
+            restrictWarnings="true"
+    >
+        <include>
+            <directory>src</directory>
+        </include>
+
+        <deprecationTrigger>
+            <function>trigger_deprecation</function>
+        </deprecationTrigger>
+    </source>
+
+    <extensions>
+    </extensions>
+</phpunit>

public/index.php

@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 use App\Kernel;
 

readme.md

@@ -25,7 +25,26 @@ First time you spin up the docker container it will generate a TOTP secret (whic
 
 Be sure to save that TOTP secret to your docker environment, so that it persists beyond removing the container.
 
+## Backup Codes
+
+It is possible to generate single-use backup codes via a console command within the docker container.
+
+```shell
+docker exec -t preauth bin/console app:generate-backup-codes [count=10]
+```
+
 ### History
+#### v0.7.0 (May 29th, 2026)
+Added ability to generate single-use backup codes.
+Removed static password and lookup token, as they were security risks.
+Updated to PHP 8.5, updated dependencies.
+
+#### v0.6.0 (Feb 10th, 2026)
+Added optional (disabled by default) ability to lookup token by static password.
+
+#### v0.5.0 (Jan 17th, 2026)
+Nonce related cleanup; added optional (disabled by default) ability to use a static password as a backup means of authentication.
+
 #### v0.4.1 (Dec 26th, 2025)
 Fixed bug which can occur if you delete cache files.
 

src/Command/GenerateBackupCodesCommand.php

@@ -0,0 +1,42 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Command;
+
+use App\PersistCache;
+use App\Service\BackupCodeInterface;
+use Psr\Cache\InvalidArgumentException;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+/** simple console command to generate backup codes
+ * usage: php bin/console app:generate-backup-codes [count] */
+final class GenerateBackupCodesCommand extends Command {
+    public function __construct(
+        private readonly BackupCodeInterface $manager,
+        private readonly PersistCache        $persistCache,
+    ) {
+        parent::__construct();
+    }
+
+    protected function configure(): void {
+        $this->setName('app:generate-backup-codes');
+        $this->setDescription('Generate single‑use backup codes')
+            ->addArgument('count', InputArgument::OPTIONAL, 'Number of codes to generate', 10);
+    }
+
+    /** @throws InvalidArgumentException */
+    protected function execute(InputInterface $input, OutputInterface $output): int {
+        /* since Kernel::terminate() does not get called, we must boot and persist explicitly */
+        $this->persistCache->boot();
+        $count = (int) $input->getArgument('count');
+        $codes = $this->manager->generate($count);
+        foreach ($codes as $code) {
+            $output->writeln($code);
+        }
+        $this->persistCache->persist();
+        return Command::SUCCESS;
+    }
+}

src/ConfigBag.php

@@ -10,7 +10,6 @@ use Symfony\Component\DependencyInjection\Attribute\Autowire;
 final readonly class ConfigBag {
     private ClockInterface $clock;
     private int $cookieTtl;
-    private string $queryPrefix;
     private string $totpUri;
     private ?int $ipTtl;
     private bool $teapot;
@@ -20,25 +19,23 @@ final readonly class ConfigBag {
 
     /** @throws InvalidArgumentException */
     public function __construct(
-        Utilities                                                 $utilities,
-        ClockInterface                                            $clock,
-        #[Autowire('%app.cookie_ttl%')] int                       $cookieTtl,
-        #[Autowire('%app.query_prefix%')] string                  $queryPrefix,
-        #[Autowire('%app.totp_uri%')] string                      $totpUri,
-        #[Autowire('%app.ip_ttl%')] ?int                          $ipTtl,
-        #[Autowire('%app.teapot%')] bool                          $teapot,
-        #[Autowire('%app.error_message%')] string                 $errorMessage,
-        #[Autowire('%app.teapot_title%')] string                  $teapotTitle,
-        #[Autowire('%app.too_many_title%')] string                $tooManyTitle,
+        Utilities                                  $utilities,
+        ClockInterface                             $clock,
+        #[Autowire('%app.cookie_ttl%')] int        $cookieTtl,
+        #[Autowire('%app.totp_uri%')] string       $totpUri,
+        #[Autowire('%app.ip_ttl%')] ?int           $ipTtl,
+        #[Autowire('%app.teapot%')] bool           $teapot,
+        #[Autowire('%app.error_message%')] string  $errorMessage,
+        #[Autowire('%app.teapot_title%')] string   $teapotTitle,
+        #[Autowire('%app.too_many_title%')] string $tooManyTitle,
     ) {
-        $this->clock = $clock;
-        $this->cookieTtl = $cookieTtl;
-        $this->queryPrefix = $queryPrefix;
-        $this->totpUri = $totpUri ?: $utilities->loadTotp();
-        $this->ipTtl = $ipTtl ?: null;
-        $this->teapot = $teapot;
+        $this->clock        = $clock;
+        $this->cookieTtl    = $cookieTtl;
+        $this->totpUri      = $totpUri ?: $utilities->loadTotp();
+        $this->ipTtl        = $ipTtl ?: null;
+        $this->teapot       = $teapot;
         $this->errorMessage = $errorMessage;
-        $this->teapotTitle = $teapotTitle;
+        $this->teapotTitle  = $teapotTitle;
         $this->tooManyTitle = $tooManyTitle;
     }
 
@@ -50,10 +47,6 @@ final readonly class ConfigBag {
         return $this->cookieTtl;
     }
 
-    public function query(string $field): string {
-        return "$this->queryPrefix$field";
-    }
-
     public function totpUri(): string {
         return $this->totpUri;
     }

src/Data/Payload.php

@@ -4,12 +4,12 @@ declare(strict_types=1);
 namespace App\Data;
 
 use App\Enum\Scope;
+use Symfony\Component\HttpFoundation\InputBag;
 
-/* When scope is Ip but ip-access is disabled, scope is to be considered Cookie. */
-/* When using password but password is disabled, request will always fail. */
+/** when scope is IP but ip-access is disabled, scope is to be considered cookie */
 final class Payload {
     public string $id;    /* session name, identifying who is logging in */
-    public string $token; /* totp, typically six digits */
+    public string $token; /* TOTP, typically six digits */
     public string $nonce; /* random unique string, to block duplicate submissions */
     public bool   $json;  /* should we return json (for the login page) */
     public Scope  $scope; /* type of access being requested */
@@ -29,27 +29,45 @@ final class Payload {
         return null;
     }
 
+    public static function load(InputBag $input): ?Payload {
+        /* convert form data into real data */
+        if ($input->has('username') && $input->has('nonce') && $input->has('totp')) {
+            return Payload::create((object)[
+                'id'    => $input->get('username'),
+                'nonce' => $input->get('nonce'),
+                'token' => $input->get('totp'),
+                'json'  => false,
+            ]);
+        }
+        return null;
+    }
+
     public static function create(object $data): ?Payload {
         /* if missing required fields id, nonce, or token */
-        if (strlen($data->id ?? '') < 1 ||
-            strlen($data->nonce ?? '') < 1 ||
-            strlen($data->token ?? '') < 1
+        if (strlen(trim($data->id    ?? '')) < 1 ||
+            strlen(trim($data->nonce ?? '')) < 1 ||
+            strlen(trim($data->token ?? '')) < 1
         ) {
             /* returns null as the input is invalid */
             return null;
         }
 
+        /* all input is limited */
         $payload = new Payload();
-        $payload->id    = $data->id;
-        $payload->nonce = $data->nonce;
+        $payload->id    = mb_substr(trim($data->id), 0, 128);
+        $payload->nonce = mb_substr(trim($data->nonce), 0, 128);
         $payload->json  = ($data->json ?? true);
         $payload->scope = Scope::tryFrom($data->scope ?? '') ?? Scope::Cookie;
-        $payload->token = $data->token;
+        $payload->token = mb_substr(trim($data->token), 0, 128);
 
         return Payload::constrict($payload);
     }
 
-    public static function constrict(Payload $payload): Payload {
+    public function toString(): string {
+        return json_encode($this);
+    }
+
+    private static function constrict(Payload $payload): Payload {
         /* When scope is None, json will be considered false. */
         if ($payload->scope === Scope::None) {
             $payload->json = false;
@@ -57,8 +75,4 @@ final class Payload {
 
         return $payload;
     }
-
-    public function toString(): string {
-        return json_encode($this);
-    }
 }

src/Enum/Scope.php

@@ -3,6 +3,7 @@ declare(strict_types=1);
 
 namespace App\Enum;
 
+/** scope defines the context of how a session is persisted */
 enum Scope: string {
     case Cookie = 'cookie';
     case Ip     = 'ip';

src/Kernel.php

@@ -9,7 +9,7 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Kernel as BaseKernel;
 
-final class Kernel extends BaseKernel {
+class Kernel extends BaseKernel {
     use MicroKernelTrait;
 
     private PersistCache $persistCache;

src/Listener/AcceptListener.php

@@ -3,6 +3,7 @@ declare(strict_types=1);
 
 namespace App\Listener;
 
+use App\Service\DomainInterface;
 use App\Trait\CookieNameTrait;
 use App\Trait\HasLoggerTrait;
 use App\Trait\StringTrait;
@@ -19,22 +20,25 @@ final readonly class AcceptListener {
 
     public function __construct(
         private CacheItemPoolInterface $sessionCache,
+        private DomainInterface        $domainManager,
     ) {}
 
     /** @throws InvalidArgumentException */
     #[AsEventListener(priority: 99)]
     public function onKernelRequest(RequestEvent $event): void {
-        /* check if they sent the preauth cookie */
-        if ($event->getRequest()->cookies->has($this->cookieName())) {
-            $cookie = $event->getRequest()->cookies->get($this->cookieName());
+        /* check if they sent the correct preauth cookie */
+        $cookieName = $this->domainManager->authBase() ?$this->authCookieName() : $this->cookieName();
+        if ($event->getRequest()->cookies->has($cookieName)) {
+            $cookie = $event->getRequest()->cookies->get($cookieName);
             $cookieKey = $this->makeCacheKey("cookie_$cookie");
-            if ($this->sessionCache->hasItem($cookieKey)) {
+            if ($cookie && $this->sessionCache->hasItem($cookieKey)) {
                 /* cookie sent corresponds to valid existing session */
                 $id = $this->sessionCache->getItem($cookieKey)->get();
                 $this->logger->debug("has valid cookie-session: $id");
-                $event->setResponse(new Response("hi $id",
-                    headers: ['Content-Type' => 'text/plain']
-                ));
+                $event->setResponse(new Response("hi $id", headers: [
+                    'Content-Type' => 'text/plain',
+                    'Remote-User'  => $id,
+                ]));
             }
         }
     }

src/Listener/AllowListener.php

@@ -30,9 +30,10 @@ final readonly class AllowListener {
                 /* ip address corresponds to valid existing session  */
                 $id = $this->sessionCache->getItem($ipKey)->get();
                 $this->logger->debug("has valid ip-session: $id");
-                $event->setResponse(new Response("hi $id",
-                    headers: ['Content-Type' => 'text/plain']
-                ));
+                $event->setResponse(new Response("hi $id", headers: [
+                    'Content-Type' => 'text/plain',
+                    'Remote-User'  => $id,
+                ]));
             }
         }
     }

src/Listener/InterceptListener.php

@@ -4,10 +4,13 @@ declare(strict_types=1);
 namespace App\Listener;
 
 use App\ConfigBag;
+use App\Service\DomainInterface;
+use App\Trait\CookieNameTrait;
 use App\Trait\HasLoggerTrait;
 use App\Trait\MakeNonceTrait;
 use Psr\Cache\InvalidArgumentException;
 use Symfony\Component\EventDispatcher\Attribute\AsEventListener;
+use Symfony\Component\HttpFoundation\Cookie;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
 use Twig\Environment;
@@ -16,28 +19,59 @@ use Twig\Error\RuntimeError;
 use Twig\Error\SyntaxError;
 
 final readonly class InterceptListener {
+    use CookieNameTrait;
     use HasLoggerTrait;
     use MakeNonceTrait;
 
     public function __construct(
-        private ConfigBag   $config,
-        private Environment $twig,
+        private ConfigBag       $config,
+        private DomainInterface $domainManager,
+        private Environment     $twig,
     ) {}
 
     /** @throws InvalidArgumentException|RuntimeError|SyntaxError|LoaderError */
     #[AsEventListener(priority: 55)]
     public function onKernelRequest(RequestEvent $event): void {
-        if ($event->getRequest()) {
-            /* by this point, we know that the request we have is:
-             * not already authorized, nor already rate-limited,
-             * nor submitting login credentials; so present the login page now */
+        /* by this point, we know that the request we have is:
+         * not already authorized, nor already rate-limited,
+         * nor submitting login credentials; so redirect or present the login page now */
+        if ($this->domainManager->getAuthSubdomain() !== $event->getRequest()->getHost() &&
+            $this->domainManager->matchesAuth($event->getRequest()->getHost())
+        ) {
+            /* host matches base-domain of auth, but not on auth subdomain, redirect */
+            $query = http_build_query(['return' => $event->getRequest()->getUri()]);
+            $event->setResponse(new Response('', Response::HTTP_SEE_OTHER,
+                ['Location' => "https://{$this->domainManager->getAuthSubdomain()}/?$query"]
+            ));
+        } else {
             $this->logger->debug("presenting login page: {$event->getRequest()->getClientIp()}");
             $content = $this->twig->render('login.html.twig', [
                 'nonce' => $this->makeNonce(),
+                'post'  => $this->domainManager->getAuthSubdomain() === $event->getRequest()->getHost(),
             ]);
-            $event->setResponse(new Response($content, Response::HTTP_UNAUTHORIZED,
-                ['Content-Type' => 'text/html']
-            ));
+            $hasCookie = (bool) $event->getRequest()->cookies->get(
+                $this->domainManager->authBase() ? $this->authCookieName() : $this->cookieName()
+            );
+            $event->setResponse($this->pruneInvalidCookie(new Response($content,
+                Response::HTTP_UNAUTHORIZED, ['Content-Type' => 'text/html']
+            ), $hasCookie, $event->getRequest()->getHost()));
         }
     }
+
+    private function pruneInvalidCookie(Response $response, bool $hasCookie, string $host): Response {
+        if ($hasCookie) {
+            /* input here must match LoginListener::setCookie() */
+            $response->headers->clearCookie(
+                $this->domainManager->authBase() ? $this->authCookieName() : $this->cookieName(),
+                '/',
+                /* if using central auth, only set the domain if the host matches */
+                $this->domainManager->matchesAuth($host) ? $this->domainManager->authBase() : null,
+                true,
+                true,
+                Cookie::SAMESITE_STRICT
+            );
+        }
+
+        return $response;
+    }
 }

src/Listener/LoginListener.php

@@ -3,25 +3,21 @@ declare(strict_types=1);
 
 namespace App\Listener;
 
+use App\ConfigBag;
 use App\Data\Payload;
-use App\Enum\Scope;
-use App\MonitorCacheKeys;
+use App\Service\DomainInterface;
+use App\Service\LoginInterface;
 use App\Trait\CookieNameTrait;
-use App\Trait\GetTotpTrait;
 use App\Trait\HasLoggerTrait;
 use App\Trait\MakeNonceTrait;
 use App\Trait\StringTrait;
-use Psr\Cache\CacheItemPoolInterface;
 use Psr\Cache\InvalidArgumentException;
 use Symfony\Component\DependencyInjection\Attribute\Target;
 use Symfony\Component\EventDispatcher\Attribute\AsEventListener;
-use Symfony\Component\HttpFoundation\Cookie;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
-use Symfony\Component\HttpKernel\Exception\HttpException;
 use Symfony\Component\RateLimiter\RateLimiterFactoryInterface;
-use Symfony\Component\Uid\Ulid;
 use Twig\Environment;
 use Twig\Error\LoaderError;
 use Twig\Error\RuntimeError;
@@ -32,140 +28,57 @@ final readonly class LoginListener {
     use HasLoggerTrait;
     use MakeNonceTrait;
     use StringTrait;
-    use GetTotpTrait;
 
-    private CacheItemPoolInterface $sessionCache;
     private RateLimiterFactoryInterface $rateLimiter;
 
-    /** @throws InvalidArgumentException */
     public function __construct(
         private                    Environment                 $twig,
-                                   CacheItemPoolInterface      $sessionCache,
         #[Target('login_limiter')] RateLimiterFactoryInterface $rateLimiter,
+        private                    DomainInterface             $domainManager,
+        private                    LoginInterface              $loginManager,
+        private                    ConfigBag                   $config,
     ) {
-        $this->sessionCache = new MonitorCacheKeys($sessionCache);
         $this->rateLimiter  = $rateLimiter;
     }
 
     /** @throws InvalidArgumentException|LoaderError|RuntimeError|SyntaxError */
     #[AsEventListener(priority: 66)]
     public function onKernelRequest(RequestEvent $event): void {
+        $payload  = null;
+        $response = null;
+
         if ($event->getRequest()->headers->has($this->headerName())) {
+            /* if request contains our "X-Preauth" header */
             $data = $event->getRequest()->headers->get($this->headerName());
             $payload = Payload::decode($data);
-            $response = null;
-            if ($payload && $payload->token) {
-                $response = $this->checkToken($payload, $event->getRequest());
-            }
+        } else if ($event->getRequest()->isMethod(Request::METHOD_POST) &&
+            $this->domainManager->getAuthSubdomain() === $event->getRequest()->getHost()
+        ) {
+            /* if request is a POST to the auth-subdomain */
+            $payload = Payload::load($event->getRequest()->getPayload());
+        } else {
+            /* no login attempt detected */
+            return;
+        }
 
-            /* token or password authentication was successful */
+        if ($payload) {
+            /* user sent a valid payload, check it */
+            $response = $this->loginManager->checkToken($payload, $event->getRequest());
+
+            /* token or backup-code authentication was successful */
             if ($response) {
                 $event->setResponse($response);
                 return;
             }
-
-            $limitReached = $this->logFailure($event->getRequest());
-
-            $this->logger->debug("logging failure for: {$event->getRequest()->getClientIp()}");
-            $event->setResponse($this->makeFailedResponse($limitReached, $payload->json ?? true));
-        }
-    }
-
-    /** @throws InvalidArgumentException */
-    private function checkToken(Payload $payload, Request $request): ?Response {
-        /* When scope is Ip but ip-access is disabled, scope will be considered Cookie. */
-        if ($payload->scope === Scope::Ip && ! $this->config->ipTtl()) {
-            /* requested to grant ip access, but that is not enabled */
-            $payload->scope = Scope::Cookie;
         }
 
-        if ($this->getTotp()->verify($payload->token, null, 10)) {
-            /* token is correct */
+        /* login attempted but unsuccessful, log and block if needed */
+        $limitReached = $this->logFailure($event->getRequest());
 
-            /* if server nonce is found and is valid */
-            $nonceItem = $this->nonceCache->getItem($payload->nonce);
-            if ($nonceItem->isHit() && $nonceItem->get()) {
-                /* mark nonce as spent */
-                $nonceItem->set(false); /* invalid */
-                $nonceItem->expiresAfter(LoginListener::NONCE_TTL); /* keep briefly */
-                $this->nonceCache->save($nonceItem);
-
-                /* token authentication successful, grant access and set response */
-                $cleanId = $this->makeCacheKey($payload->id);
-
-                /* if they just want this one page, return ok, to grant them access */
-                $response = new Response("hi $cleanId",
-                    headers: ['Content-Type' => 'text/plain']
-                );
-
-                if ($payload->scope !== Scope::None) {
-                    /* grant access based on the requested scope */
-                    if ($payload->scope === Scope::Cookie) {
-                        $response->headers->setCookie($this->setCookie($cleanId));
-                    } else if ($payload->scope === Scope::Ip) {
-                        $this->setIp($cleanId, $request->getClientIp());
-                    }
-
-                    if ($payload->json) {
-                        $contentType = 'application/json';
-                        $content     = json_encode([
-                            'message' => 'Login successful',
-                            'nonce'   => null,
-                        ]);
-                    } else {
-                        $contentType = 'text/html';
-                        $content     = "hi $cleanId, please reload";
-                    }
-
-                    $response->setContent($content)
-                        ->setStatusCode(Response::HTTP_TEMPORARY_REDIRECT)
-                        ->headers->set('Location',
-                            "{$request->getPathInfo()}{$request->getQueryString()}"
-                        );
-                    $response->headers->set('Content-Type', $contentType);
-                }
-
-                $this->logger->debug("successful login for: $cleanId");
-                return $response;
-            }
-        }
-        return null;
-    }
-
-    /** @throws InvalidArgumentException */
-    private function setCookie(string $id): Cookie {
-        /* successful auth with token, store session and set the cookie */
-        $ulid = new Ulid();
-        $sessionCookie = $this->sessionCache->getItem(
-            $this->makeCacheKey("cookie_$ulid")
-        );
-        if ($sessionCookie->isHit()) {
-            /* it is supposed to be impossible to have collisions */
-            $this->logger->error("aborting: ULID collision");
-            throw new HttpException(Response::HTTP_INTERNAL_SERVER_ERROR, 'Internal Server Error');
-        }
-        $sessionCookie->set($id);
-        $sessionCookie->expiresAfter($this->config->cookieTtl());
-        $this->sessionCache->save($sessionCookie);
-
-        return Cookie::create(
-            name: $this->cookieName(),
-            value: $ulid->toString(),
-            expire: time() + $this->config->cookieTtl(),
-            secure: true,
-            sameSite: Cookie::SAMESITE_STRICT
-        );
-    }
-
-    /** @throws InvalidArgumentException */
-    private function setIp(string $id, string $ip): void {
-        /* successful auth with token, requested scope of ip (and ip access enabled) */
-        $ipKey = $this->makeCacheKey("ip_$ip");
-
-        $sessionIp = $this->sessionCache->getItem($ipKey);
-        $sessionIp->set($id);
-        $sessionIp->expiresAfter($this->config->ipTtl());
-        $this->sessionCache->save($sessionIp);
+        $this->logger->debug("logging failure for: {$event->getRequest()->getClientIp()}");
+        $event->setResponse($this->makeFailedResponse($limitReached, $payload->json ?? true,
+            $event->getRequest()->getHost(), $this->makeCacheKey($payload ? $payload->id : '')
+        ));
     }
 
     private function logFailure(Request $request): bool {
@@ -174,7 +87,7 @@ final readonly class LoginListener {
     }
 
     /** @throws InvalidArgumentException|RuntimeError|SyntaxError|LoaderError */
-    private function makeFailedResponse(bool $limited, bool $json): Response {
+    private function makeFailedResponse(bool $limited, bool $json, string $host, string $username): Response {
         if ($limited) {
             $status = $this->config->teapot() ? Response::HTTP_I_AM_A_TEAPOT
                 : Response::HTTP_TOO_MANY_REQUESTS;
@@ -187,6 +100,8 @@ final readonly class LoginListener {
         $answer = [
             'message' => $message,
             'nonce'   => $this->makeNonce(),
+            'post'    => $this->domainManager->getAuthSubdomain() === $host,
+            'username' => $username,
         ];
 
         if ($json) {

src/MonitorCacheKeys.php

@@ -8,13 +8,13 @@ use Psr\Cache\CacheItemInterface;
 use Psr\Cache\CacheItemPoolInterface;
 use Psr\Cache\InvalidArgumentException;
 
-/* We must not store the key-list item or values within this object,
- * because it can change from outside this object instance. */
+/* we must *NOT* store the key-list item or values within this object
+ * because it can change from outside this object instance */
 final readonly class MonitorCacheKeys implements CacheItemPoolInterface {
-    private const KEY_LIST = '__key_list';
-    private const CHANGE_LIST = '__chg_list';
-    public  const UPDATED = 1;
-    public  const REMOVED = 2;
+    private const string KEY_LIST = '__key_list';
+    private const string CHANGE_LIST = '__chg_list';
+    public const int UPDATED = 1;
+    public const int REMOVED = 2;
 
     private CacheItemPoolInterface $cache;
 
@@ -135,7 +135,7 @@ final readonly class MonitorCacheKeys implements CacheItemPoolInterface {
     }
 
     /** @throws InvalidArgumentException|OutOfBoundsException */
-    private function update(CacheItemInterface $item) {
+    private function update(CacheItemInterface $item): void {
         $this->isValid($item->getKey());
         $keyList = $this->cache->getItem(self::KEY_LIST);
         $keyValues = $keyList->get();

src/PersistCache.php

@@ -7,6 +7,7 @@ use Psr\Cache\CacheItemPoolInterface;
 use Psr\Cache\InvalidArgumentException;
 use Symfony\Component\DependencyInjection\Attribute\Autoconfigure;
 
+/* need autoconfigure so we get it from the service container in Kernel->boot() */
 #[Autoconfigure(public: true)]
 final readonly class PersistCache {
     private MonitorCacheKeys $sessionCache;

src/Service/BackupCodeInterface.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Service;
+
+
+use Exception;
+use Psr\Cache\InvalidArgumentException;
+
+/** backup-codes are case‑insensitive alphanumeric strings
+ * they are single-use and marked as used after successful authentication */
+interface BackupCodeInterface {
+    /** generate a set of backup-codes and return them
+     * @param int $count Number of codes to generate
+     * @return string[] Generated backup codes
+     * @throws InvalidArgumentException|Exception */
+    public function generate(int $count = 0): array;
+
+    /** @throws InvalidArgumentException */
+    public function expire(): void;
+
+    /** check if backup-code is valid and mark it as used
+     * @param string $code Code supplied by the client
+     * @return bool true if the code is valid and unused
+     * @throws InvalidArgumentException */
+    public function verifyAndConsume(string $code): bool;
+}

src/Service/BackupCodeManager.php

@@ -0,0 +1,104 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Service;
+
+use App\MonitorCacheKeys;
+use App\Trait\HasLoggerTrait;
+use App\Trait\StringTrait;
+use DateTimeImmutable;
+use Exception;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Cache\InvalidArgumentException;
+use App\Trait\GetTotpTrait;
+
+/** backup-codes are case‑insensitive alphanumeric strings
+ * they are single-use and marked as used after successful authentication */
+final readonly class BackupCodeManager implements BackupCodeInterface {
+    use GetTotpTrait;
+    use HasLoggerTrait;
+    use StringTrait;
+
+    private const int DEFAULT_COUNT = 10;
+    /* php base_convert() will break if given too long of an input */
+    const int MAX_LENGTH = 64;
+
+    private CacheItemPoolInterface $sessionCache;
+
+    /** @throws InvalidArgumentException */
+    public function __construct(CacheItemPoolInterface $sessionCache) {
+        $this->sessionCache = new MonitorCacheKeys($sessionCache);
+    }
+
+    /** generate a set of backup-codes and return them
+     * @param int $count Number of codes to generate
+     * @return string[] Generated backup codes
+     * @throws InvalidArgumentException|Exception */
+    public function generate(int $count = self::DEFAULT_COUNT): array {
+        $length = min($this->getTotp()->getDigits() + 2, self::MAX_LENGTH);
+        $codes = [];
+        for ($i = 0; $i < $count; $i++) {
+            /* output is alphanumeric string of given length */
+            $codes[] = strtolower(str_pad(substr(base_convert(bin2hex(
+                random_bytes($length)
+            ), 16, 36), 0, $length), $length, '0', STR_PAD_LEFT));
+        }
+        $this->saveCodes($codes);
+        $this->logger->info("generated {$count} backup codes");
+        return $codes;
+    }
+
+    /** @throws InvalidArgumentException */
+    public function expire(): void {
+        $itemsToRemove = [];
+        foreach ($this->sessionCache->getKeys() as $key) {
+            if (str_starts_with($key, 'backup_')) {
+                $itemsToRemove[] = $key;
+            }
+        }
+        if (count($itemsToRemove) > 0) {
+            $this->sessionCache->deleteItems($itemsToRemove);
+        }
+    }
+
+    /** check if backup-code is valid and mark it as used
+     * @param string $code Code supplied by the client
+     * @return bool true if the code is valid and unused
+     * @throws InvalidArgumentException */
+    public function verifyAndConsume(string $code): bool {
+        /* remove unallowed characters, since backup codes are case-insensitive alphanumeric */
+        $backupKey = 'backup_' . preg_replace('/[^a-z0-9]+/', '', strtolower($code));
+        $backupItem = $this->sessionCache->getItem($this->makeCacheKey($backupKey));
+        $this->logger->debug("checking backup code '{$backupKey}': " . ($backupItem->isHit() ? 'HIT & ' : 'miss & ') . ($backupItem->get() ? 'VALID' : 'invalid'));
+        if ($backupItem->isHit() && $backupItem->get()) {
+            $this->logger->debug("valid backup code");
+            /* mark backup code as spent */
+            $backupItem->set(false); /* used */
+            /* per PSR6, if no expiration is set, implementation may set a default,
+             * we want this to keep forever, so a few hundred years should do it */
+            $backupItem->expiresAt(DateTimeImmutable::createFromFormat(
+                'Y-m-d', '2999-12-31'
+            ));
+            $this->sessionCache->save($backupItem);
+
+            return true;
+        }
+        return false;
+    }
+
+    /** @throws InvalidArgumentException */
+    private function saveCodes(array $codes): void {
+        foreach ($codes as $code) {
+            $backupItem = $this->sessionCache->getItem($this->makeCacheKey(strtolower("backup_$code")));
+            /* mark backup code as ready */
+            $backupItem->set(true);
+            /* per PSR6, if no expiration is set, implementation may set a default,
+             * we want this to keep forever, so a few hundred years should do it */
+            $backupItem->expiresAt(DateTimeImmutable::createFromFormat(
+                'Y-m-d', '2999-12-31'
+            ));
+            $this->sessionCache->saveDeferred($backupItem);
+        }
+        $this->sessionCache->commit();
+    }
+}

src/Service/DomainInterface.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace App\Service;
+
+interface DomainInterface {
+    /** IE: "auth.example.com" or null if not using a separate subdomain
+     * @return ?string Returns auth subdomain if configured, otherwise null */
+    public function getAuthSubdomain(): ?string;
+
+    /** check if given url is an acceptable url for redirection
+     * @param string $url Where we are thinking of sending the user
+     * @return bool Returns true if it is acceptable to send the user there */
+    public function validReturn(string $url): bool;
+
+    /** check if host-base matches auth-base
+     * @param string $host
+     * @return bool returns true if and only if host matches base domain of auth */
+    public function matchesAuth(string $host): bool;
+
+    /** IE: "example.com" if central auth is something like "auth.example.com"
+     * @return string|null returns base domain if we are doing central auth */
+    public function authBase(): ?string;
+}

src/Service/DomainManager.php

@@ -0,0 +1,120 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Service;
+
+use Symfony\Component\DependencyInjection\Attribute\Autowire;
+
+final readonly class DomainManager implements DomainInterface {
+    /* top-level-domains which are known to have multiple parts */
+    private const array TLD = [
+        'ai'  => ['com','net','off','org'],
+        'am'  => ['radio'],
+        'com' => ['br','cn','co','de','eu','gr','it','jpn','mex','ru','sa','uk','us','za'],
+        'de'  => ['com'],
+        'fm'  => ['radio'],
+        'gg'  => ['co','net','org'],
+        'in'  => ['co','firm','gen','ind','net','org'],
+        'je'  => ['co','net','org'],
+        'mx'  => ['com','net','org'],
+        'net' => ['gb','hu','in','jp','se','uk'],
+        'nz'  => ['co','net','org'],
+        'org' => ['ae','us'],
+        'ph'  => ['com','net','org'],
+        'se'  => ['com'],
+        'uk'  => ['co','me','org'],
+    ];
+
+    private bool $subdomainRedirect;
+    private string $authSubdomain;
+
+    public function __construct(
+        #[Autowire('%app.subdomain_redirect%')] bool $subdomainRedirect,
+        #[Autowire('%app.auth_subdomain%')] string   $authSubdomain,
+    ) {
+        $this->subdomainRedirect = $subdomainRedirect;
+        $this->authSubdomain = $authSubdomain;
+    }
+
+    /** IE: "auth.example.com" or null if not using a separate subdomain
+     * @return ?string Returns auth subdomain if configured, otherwise null */
+    public function getAuthSubdomain(): ?string {
+        if ($this->authBase()) {
+            return $this->authSubdomain;
+        }
+        return null;
+    }
+
+    /** check if given url is an acceptable url for redirection
+     * @param string $url Where we are thinking of sending the user
+     * @return bool Returns true if it is acceptable to send the user there */
+    public function validReturn(string $url): bool {
+        /* ensure url is valid and, when using an auth subdomain,
+         * that the url host matches the base domain */
+        if (!filter_var($url, FILTER_VALIDATE_URL)) {
+            return false;
+        }
+
+        if ($this->authBase()) {
+            $host = parse_url($url, PHP_URL_HOST);
+            if ($host === null) {
+                return false;
+            }
+            /* do not send the user to another domain */
+            return $this->matchesAuth($host);
+        }
+
+        return true;
+    }
+
+    /** check if host-base matches auth-base
+     * @param string $host
+     * @return bool returns true if and only if host matches base domain of auth */
+    public function matchesAuth(string $host): bool {
+        $hostBase = $this->baseDomain($host);
+        $authBase = $this->baseDomain($this->authSubdomain);
+        return $this->subdomainRedirect && $this->authSubdomain &&
+            $authBase && $authBase === $hostBase;
+    }
+
+    /** IE: "example.com" if central auth is something like "auth.example.com"
+     * @return string|null returns base domain if we are doing central auth */
+    public function authBase(): ?string {
+        if ($this->subdomainRedirect && $this->authSubdomain && $this->baseDomain($this->authSubdomain)) {
+            return $this->baseDomain($this->authSubdomain);
+        }
+        return null;
+    }
+
+    /** this lets us determine the base domain of the given ip, localhost, or domain
+     * "service.example.co.uk" into "example.co.uk" and "service.example.com" into "example.com"
+     * things like "localhost" and "8.8.8.8" will return null
+     * @param string $host ip, localhost, or domain with zero or more subdomains
+     * @return ?string returns null if host is ip or localhost otherwise domain with all subdomains removed */
+    private function baseDomain(string $host): ?string {
+        /* if host is an ip address (or localhost), leave it as is */
+        if (filter_var($host, FILTER_VALIDATE_IP) || $host === 'localhost') {
+            return null;
+        }
+
+        $parts = explode('.', $host);
+        $keep = $this->baseLength($parts);
+        $parts = array_slice($parts, -$keep);
+        return implode('.', $parts);
+    }
+
+    /** IE: ["www", "example", "com"] or ["www", "example", "co", "uk"]
+     * @param string[] $parts pieces of a domain split by "." dot
+     * @return int typically 2 but sometimes 3 */
+    private function baseLength(array $parts): int {
+        $length = count($parts);
+        $baseLength = min(2, $length);
+        /* check if host should retain 3 parts, due to TLD */
+        if (count($parts) > 2 && isset(self::TLD[$parts[$length-1]]) &&
+            in_array($parts[$length-2], self::TLD[$parts[$length-1]], true)
+        ) {
+            $baseLength = min(3, $length);
+        }
+        return $baseLength;
+    }
+}

src/Service/LoginInterface.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace App\Service;
+
+use App\Data\Payload;
+use Psr\Cache\InvalidArgumentException;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+interface LoginInterface {
+    /** @throws InvalidArgumentException */
+    public function checkToken(Payload $payload, Request $request): ?Response;
+}

src/Service/LoginManager.php

@@ -0,0 +1,148 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Service;
+
+use App\Data\Payload;
+use App\Enum\Scope;
+use App\MonitorCacheKeys;
+use App\Trait\CookieNameTrait;
+use App\Trait\GetTotpTrait;
+use App\Trait\MakeNonceTrait;
+use App\Trait\StringTrait;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Cache\InvalidArgumentException;
+use Symfony\Component\HttpFoundation\Cookie;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Exception\HttpException;
+use Symfony\Component\Uid\Ulid;
+
+final readonly class LoginManager implements LoginInterface {
+    use CookieNameTrait;
+    use GetTotpTrait;
+    use MakeNonceTrait;
+    use StringTrait;
+
+    private CacheItemPoolInterface $sessionCache;
+
+    /** @throws InvalidArgumentException */
+    public function __construct(
+                CacheItemPoolInterface $sessionCache,
+        private BackupCodeInterface    $backupCodeManager,
+        private DomainInterface        $domainManager,
+    ) {
+        $this->sessionCache = new MonitorCacheKeys($sessionCache);
+    }
+
+    /** @throws InvalidArgumentException */
+    public function checkToken(Payload $payload, Request $request): ?Response {
+        /* when scope is IP but ip-access is disabled, scope is to be considered cookie */
+        if ($payload->scope === Scope::Ip && ! $this->config->ipTtl()) {
+            /* requested to grant ip access, but that is not enabled */
+            $payload->scope = Scope::Cookie;
+        }
+
+        if ($this->getTotp()->verify($payload->token, null, 10) ||
+            $this->backupCodeManager->verifyAndConsume($payload->token)
+        ) {
+            /* token is correct (TOTP or Backup) */
+
+            /* if server nonce is found and is valid */
+            $nonceItem = $this->nonceCache->getItem($this->makeCacheKey($payload->nonce));
+            if ($nonceItem->isHit() && $nonceItem->get()) {
+                /* mark nonce as spent */
+                $nonceItem->set(false); /* invalid */
+                $nonceItem->expiresAfter(LoginManager::NONCE_TTL); /* keep briefly */
+                $this->nonceCache->save($nonceItem);
+
+                /* token authentication successful, grant access and set response */
+                $cleanId = $this->makeCacheKey($payload->id);
+
+                /* if they just want this one page, return ok, to grant them access */
+                $response = new Response("hi $cleanId", headers: [
+                    'Content-Type' => 'text/plain',
+                    'Remote-User'  => $cleanId,
+                ]);
+
+                if ($payload->scope !== Scope::None) {
+                    /* grant access based on the requested scope */
+                    if ($payload->scope === Scope::Cookie) {
+                        $response->headers->setCookie($this->setCookie($cleanId, $request->getHost()));
+                    } else if ($payload->scope === Scope::Ip) {
+                        $this->setIp($cleanId, $request->getClientIp());
+                    }
+
+                    if ($payload->json) {
+                        $contentType = 'application/json';
+                        $content     = json_encode([
+                            'message' => 'Login successful',
+                            'nonce'   => null,
+                        ]);
+                    } else {
+                        $contentType = 'text/html';
+                        $content     = "hi $cleanId, please reload";
+                    }
+
+                    $location = $request->query->has('return') &&
+                    $this->domainManager->validReturn($request->query->get('return')) ?
+                        "{$request->query->get('return')}" :
+                        "{$request->getPathInfo()}{$request->getQueryString()}";
+
+                    /* force redirect to use GET method (important when using central auth) */
+                    $response->setContent($content)
+                        ->setStatusCode(Response::HTTP_SEE_OTHER)
+                        ->headers->set('Location', $location);
+                    $response->headers->set('Content-Type', $contentType);
+                }
+
+                $this->logger->debug("successful login for: $cleanId");
+                return $response;
+            }
+        }
+        return null;
+    }
+
+    /** @throws InvalidArgumentException */
+    private function setCookie(string $id, string $host): Cookie {
+        /* successful auth with token, store session and set the cookie */
+        $ulid = new Ulid();
+        $sessionCookie = $this->sessionCache->getItem(
+            $this->makeCacheKey("cookie_$ulid")
+        );
+        if ($sessionCookie->isHit()) {
+            /* it is supposed to be impossible to have collisions */
+            $this->logger->error("aborting: ULID collision");
+            throw new HttpException(Response::HTTP_INTERNAL_SERVER_ERROR, 'Internal Server Error');
+        }
+        $sessionCookie->set($id);
+        $sessionCookie->expiresAfter($this->config->cookieTtl());
+        $this->sessionCache->save($sessionCookie);
+
+        /* when using subdomain-auth we have to use a different cookie name, as the
+         * "__Host-Http-" prefix we normally use does not allow domain to be set */
+        /* changes here must be reflected in InterceptListener::pruneInvalidCookie() */
+        return Cookie::create(
+            name: $this->domainManager->authBase() ? $this->authCookieName() : $this->cookieName(),
+            value: $ulid->toString(),
+            expire: time() + $this->config->cookieTtl(),
+            path: '/',
+            /* if using central auth, only set the domain if the host matches */
+            domain: $this->domainManager->matchesAuth($host) ? $this->domainManager->authBase() : null,
+            secure: true,
+            httpOnly: true,
+            sameSite: Cookie::SAMESITE_STRICT,
+        );
+    }
+
+    /** @throws InvalidArgumentException */
+    private function setIp(string $id, string $ip): void {
+        /* successful auth with token, requested scope of ip (and ip access enabled) */
+        $ipKey = $this->makeCacheKey("ip_$ip");
+
+        $sessionIp = $this->sessionCache->getItem($ipKey);
+        $sessionIp->set($id);
+        $sessionIp->expiresAfter($this->config->ipTtl());
+        $this->sessionCache->save($sessionIp);
+    }
+}

src/Trait/CookieNameTrait.php

@@ -4,13 +4,18 @@ declare(strict_types=1);
 namespace App\Trait;
 
 trait CookieNameTrait {
-    private const COOKIE_NAME = '__Host-Http-Preauth';
-    private const HEADER_NAME = 'X-Preauth';
+    private const string COOKIE_NAME = '__Host-Http-Preauth';
+    private const string AUTH_COOKIE_NAME = '__Http-Domain-Preauth';
+    private const string HEADER_NAME = 'X-Preauth';
 
     final protected function cookieName(): string {
         return static::COOKIE_NAME;
     }
 
+    final protected function authCookieName(): string {
+        return static::AUTH_COOKIE_NAME;
+    }
+
     final protected function headerName(): string {
         return static::HEADER_NAME;
     }

src/Trait/GetTotpTrait.php

@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 namespace App\Trait;
 

src/Trait/MakeNonceTrait.php

@@ -12,10 +12,11 @@ use Symfony\Contracts\Service\Attribute\Required;
 
 trait MakeNonceTrait {
     use HasLoggerTrait;
+    use StringTrait;
 
     /* 15 bytes neatly fits in base64 */
-    private const NONCE_LENGTH = 15;
-    private const NONCE_TTL = 120;
+    private const int NONCE_LENGTH = 15;
+    private const int NONCE_TTL = 120;
 
     protected readonly CacheItemPoolInterface $nonceCache;
 
@@ -30,7 +31,7 @@ trait MakeNonceTrait {
         $nonce = rtrim(strtr(base64_encode(random_bytes(
             static::NONCE_LENGTH
         )), '+/', '-_'), '=');
-        $nonceItem = $this->nonceCache->getItem($nonce);
+        $nonceItem = $this->nonceCache->getItem($this->makeCacheKey($nonce));
 
         if ($nonceItem->isHit()) {
             if ($retries < 1) {

src/Trait/StringTrait.php

@@ -5,9 +5,9 @@ namespace App\Trait;
 
 trait StringTrait {
     /* cache keys can safely use alphanumeric, "_", and ".", remove the rest */
-    private const KEY_REGEX = '/[^A-Za-z0-9_.]+/';
+    private const string KEY_REGEX = '/[^A-Za-z0-9_.]+/';
 
     public function makeCacheKey(string $name): string {
-        return preg_replace(static::KEY_REGEX, '_', $name);
+        return mb_substr(preg_replace(static::KEY_REGEX, '_', $name), 0, 128);
     }
 }

src/Utilities.php

@@ -48,20 +48,14 @@ final readonly class Utilities {
     }
 
     private function showTotp(string $totp): void {
-//        /* only show this at most, every 5 minutes */
-//        $suppress = $this->appPool->getItem('suppress');
-//        if ( ! $suppress->isHit()) {
         $writer = new Writer(new PlainTextRenderer());
         file_put_contents(
             'php://stderr', <<<RAW
             {$writer->writeString($totp)}
             $totp
-            loading totp, because the env is not set, please copy above into TOTP_URI
+            loading TOTP, because the env is not set, please copy above into TOTP_URI
 
             RAW, FILE_APPEND
         );
-//            $suppress->expiresAfter(300);
-//            $this->appPool->save($suppress);
-//        }
     }
 }

symfony.lock

@@ -1,4 +1,19 @@
 {
+    "phpunit/phpunit": {
+        "version": "13.2",
+        "recipe": {
+            "repo": "github.com/symfony/recipes",
+            "branch": "main",
+            "version": "11.1",
+            "ref": "ca0bc067abfb40a8de1b2561b96cbfc2b833c314"
+        },
+        "files": [
+            ".env.test",
+            "phpunit.dist.xml",
+            "tests/bootstrap.php",
+            "bin/phpunit"
+        ]
+    },
     "symfony/console": {
         "version": "7.4",
         "recipe": {

templates/_script.html.twig

@@ -1,52 +1,84 @@
 <script>
-    const form    = document.getElementById('preauth-form');
-    const message = document.getElementById('preauth-message');
+const form    = document.getElementById('preauth-form');
+const message = document.getElementById('preauth-message');
+const body    = document.getElementById('preauth-body');
+const style   = document.getElementById('preauth-style');
 
-    form.addEventListener('submit', (event) => {
-        event.preventDefault();
+form.addEventListener('submit', (event) => {
+    event.preventDefault();
 
-        /* make base64url string containing our payload json object */
-        const data = btoa(JSON.stringify({
-            id:    form.preauth_id.value,
-            token: form.preauth_token.value,
-            nonce: form.preauth_nonce.value,
-            json:  true
-        })).replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');
+    {# make base64url string containing our payload json object #}
+    const data = btoa(JSON.stringify({
+        id:    form.username.value?.trim() ?? '',
+        token: form.totp.value?.trim() ?? '',
+        nonce: form.nonce.value?.trim() ?? '',
+        json:  true
+    })).replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');
 
-        /* send our request to the server */
-        fetch(window.location.href, {
-            method: 'GET',
-            headers: { 'X-Preauth': data },
-        }).then((response) => {
-            if (response.headers.has('Location')) {
-                /* follow redirect (not needed in most browsers) */
-                window.location.href = response.headers.get('Location');
-            } else if (response.headers.get('Content-Type') === 'application/json') {
-                /* got json, update the page */
-                response.json().then((content) => {
-                    if (Object.hasOwn(content, 'message')) {
-                        message.innerText = content.message;
-                    }
-                    if (Object.hasOwn(content, 'nonce')) {
-                        form.preauth_nonce.value = content.nonce;
-                        form.preauth_token.value = '';
-                        form.preauth_token.focus();
-                    }
-                }).catch((error) => {
-                    console.log('failed to parse json from response');
-                    console.log(error);
-                });
-            } else { /* non-json, non-redirect response */
-                /* overwrite the page */
-                response.text().then((text) => {
-                    document.open();
-                    document.write(text);
-                    document.close();
-                }).catch((error) => {
-                    console.log('failed to get text from response');
-                    console.log(error);
-                });
-            }
-        });
+    {# send our request to the server #}
+    fetch(window.location.href, {
+        method: 'GET',
+        headers: { 'X-Preauth': data },
+    }).then((response) => {
+        {% if env.debug > 2 -%}
+            console.log(response);
+        {% endif -%}
+        if (response.headers.has('Location')) {
+            {# follow redirect (probably not needed) #}
+            {% if env.debug > 2 -%}
+                console.log('got redirect response');
+            {% endif -%}
+            window.location.href = response.headers.get('Location');
+        } else if (response.headers.get('Content-Type')?.toLowerCase().includes('application/json') ?? false) {
+            {# got json, update the page #}
+            {% if env.debug > 2 -%}
+                console.log('got json response');
+            {% endif -%}
+            response.json().then((content) => {
+                if (Object.hasOwn(content, 'message')) {
+                    message.innerText = content.message;
+                }
+                if (Object.hasOwn(content, 'nonce')) {
+                    form.nonce.value = content.nonce;
+                    form.totp.value = '';
+                    form.totp.focus();
+                }
+            }).catch((error) => {
+                console.log('failed to parse json from response');
+                console.log(error);
+            });
+        } else if (response.headers.get('Content-Type')?.toLowerCase().includes('text/html') ?? false) {
+            {# got html, replace the page #}
+            {% if env.debug > 2 -%}
+                console.log('got html response');
+            {% endif -%}
+            response.text().then((html) => {
+                document.open();
+                document.write(html);
+                document.close();
+            }).catch((error) => {
+                console.log('failed to get html from response');
+                console.log(error);
+            });
+        } else {
+            {# non-json, non-html, non-redirect response #}
+            {# update the page, change style to plain text #}
+            {% if env.debug > 2 -%}
+                console.log('got misc response');
+            {% endif -%}
+            response.text().then((text) => {
+                body.innerText = text;
+                style.disabled = true;
+                body.style.whiteSpace = 'pre-wrap';
+                body.style.wordWrap = 'break-word';
+            }).catch((error) => {
+                console.log('failed to get text from response');
+                console.log(error);
+            });
+        }
+    }).catch((error) => {
+        console.log('failed to get response');
+        console.log(error);
     });
+});
 </script>

templates/_style.html.twig

@@ -1,4 +1,4 @@
-<style>
+<style id="preauth-style">
 * { margin: 0; padding: 0.25em; }
 html { background-color: {{ env.bg_color }}; color: {{ env.fg_color }}; display: table;
     font-family: sans-serif; font-size: 1.5em; height: 100%; padding: 0; width: 100%; }

templates/base.html.twig

@@ -4,10 +4,9 @@
     <meta charset="utf-8">
     <title>{{ env.title }}</title>
     <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
-    {{ include('_style.html.twig') }}
+    {{- include('_style.html.twig') -}}
 </head>
-<body>
+<body id="preauth-body">
 {% block content %}{% endblock %}
-{{ include('_script.html.twig') }}
 </body>
 </html>

templates/login.html.twig

@@ -3,14 +3,17 @@
 {% block content %}
 <h1>{{ env.title }}</h1>
 <p id="preauth-message">{{ message|default }}</p>
-<form id="preauth-form">
-    <input id="preauth-nonce" type="hidden" name="preauth_nonce" value="{{ nonce }}">
-    <div class="right"><label for="preauth-id">{{ env.id_name }}:</label></div>
-    <div><input type="text" name="preauth_id" id="preauth-id"
-            autocomplete="username" required="required" autofocus="autofocus"></div>
-        <div class="right"><label for="preauth-token">{{ env.token_name }}:</label></div>
-        <div><input type="text" name="preauth_token" id="preauth-token"
-                autocomplete="one-time-code" required="required"></div>
+<form id="preauth-form" {% if post ?? false -%} method="post" {%- endif %}>
+    <input id="nonce" type="hidden" name="nonce" value="{{ nonce }}">
+    <div class="right"><label for="username">{{ env.id_name }}:</label></div>
+    <div><input type="text" name="username" id="username" {% if username ?? false %}value="{{ username }}"{% endif %}
+        autocomplete="username" required="required" autofocus="autofocus"></div>
+    <div class="right"><label for="totp">{{ env.token_name }}:</label></div>
+    <div><input type="text" name="totp" id="totp"
+        autocomplete="one-time-code" required="required"></div>
     <div class="center"><button type="submit">{{ env.submit_name }}</button></div>
 </form>
+{% if not post ?? false %}
+    {{- include('_script.html.twig') -}}
+{% endif %}
 {% endblock %}

tests/Functional/AuthenticationFlowTest.php

@@ -0,0 +1,485 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Functional;
+
+use App\Data\Payload;
+use App\Enum\Scope;
+use OTPHP\TOTP;
+use Symfony\Bundle\FrameworkBundle\KernelBrowser;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+
+/**
+ * End-to-end functional tests exercising the full HTTP kernel: the request
+ * travels through RejectListener -> LoginListener -> AllowListener ->
+ * AcceptListener -> InterceptListener and the services they orchestrate.
+ */
+final class AuthenticationFlowTest extends WebTestCase {
+
+    private const string TOTP_SECRET = 'JBSWY3DPEHPK3PXP';
+    private const string COOKIE_NAME = '__Host-Http-Preauth';
+
+    protected static function createClient(array $options = [], array $server = []): KernelBrowser
+    {
+        $client = parent::createClient($options, $server);
+        // The app stores nonces in the (in-memory) nonceCache pool.  In
+        // production APCu keeps them across requests, but KernelBrowser
+        // reboots the kernel between requests by default which would lose
+        // them.  Disable the reboot so the nonce issued on the login-page
+        // request survives to the login-submission request.
+        $client->disableReboot();
+
+        return $client;
+    }
+
+    private function validTotpCode(): string {
+        // the app uses the real system clock, so generate the code for now()
+        return TOTP::createFromSecret(self::TOTP_SECRET)->now();
+    }
+
+    /** base64url-encode a payload, matching the client-side JS / X-Preauth header. */
+    private function encodePayload(array $data): string {
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+        return rtrim(strtr(base64_encode($json), '+/', '-_'), '=');
+    }
+
+    private function loginPayload(
+        string $id = 'testuser',
+        ?string $token = null,
+        string $nonce = 'test-nonce-abc',
+        bool $json = true,
+    ): string {
+        return $this->encodePayload([
+            'id'    => $id,
+            'token' => $token ?? $this->validTotpCode(),
+            'nonce' => $nonce,
+            'json'  => $json,
+        ]);
+    }
+
+    /* ── unauthenticated access ──────────────────────────────────────── */
+
+    public function testUnauthenticatedRequestShowsLoginPage(): void {
+        $client = static::createClient();
+        $client->request('GET', '/');
+
+        // login page is served with 401 (Unauthorized) to signal the proxy
+        self::assertSame(401, $client->getResponse()->getStatusCode());
+        self::assertSelectorExists('form#preauth-form');
+        self::assertSelectorExists('input[name="nonce"]');
+        self::assertSelectorExists('input[name="username"]');
+        self::assertSelectorExists('input[name="totp"]');
+    }
+
+    public function testLoginPageContainsGeneratedNonce(): void {
+        $client = static::createClient();
+        $crawler = $client->request('GET', '/');
+
+        $nonceInput = $crawler->filter('input[name="nonce"]')->attr('value');
+        self::assertNotEmpty($nonceInput);
+        // base64url charset
+        self::assertMatchesRegularExpression('/^[A-Za-z0-9_-]+$/', $nonceInput);
+    }
+
+    public function testLoginFormDoesNotUsePostMethodWithoutAuthSubdomain(): void {
+        $client = static::createClient();
+        $crawler = $client->request('GET', '/');
+
+        $form = $crawler->filter('form#preauth-form');
+        // without central auth, the form should NOT have method="post"
+        $method = $form->attr('method');
+        self::assertNull($method);
+    }
+
+    /* ── successful TOTP login ────────────────────────────────────────── */
+
+    public function testSuccessfulTotpLoginViaHeaderSetsCookieAndRedirects(): void {
+        $client = static::createClient();
+
+        // first, grab a valid nonce from the login page
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+        self::assertNotEmpty($nonce);
+
+        // now submit a valid TOTP via the X-Preauth header
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'alice',
+                'token' => $this->validTotpCode(),
+                'nonce' => $nonce,
+                'json'  => true,
+            ]),
+        ]);
+
+        $response = $client->getResponse();
+        self::assertSame(303, $response->getStatusCode()); // SEE_OTHER
+        self::assertTrue($response->headers->has('Location'));
+        // a session cookie should be set
+        $cookies = $response->headers->getCookies();
+        $hasPreauthCookie = false;
+        foreach ($cookies as $cookie) {
+            if (str_contains($cookie->getName(), 'Preauth')) {
+                $hasPreauthCookie = true;
+            }
+        }
+        self::assertTrue($hasPreauthCookie, 'Expected a preauth cookie to be set after login');
+    }
+
+    public function testSuccessfulLoginReturnsJsonWhenJsonRequested(): void {
+        $client = static::createClient();
+
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'bob',
+                'token' => $this->validTotpCode(),
+                'nonce' => $nonce,
+                'json'  => true,
+            ]),
+        ]);
+
+        $response = $client->getResponse();
+        self::assertSame(303, $response->getStatusCode());
+        self::assertSame('application/json', $response->headers->get('Content-Type'));
+        $body = json_decode($response->getContent(), true);
+        self::assertSame('Login successful', $body['message']);
+    }
+
+    public function testSuccessfulLoginReturnsHtmlWhenJsonFalse(): void {
+        $client = static::createClient();
+
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'carol',
+                'token' => $this->validTotpCode(),
+                'nonce' => $nonce,
+                'json'  => false,
+            ]),
+        ]);
+
+        $response = $client->getResponse();
+        self::assertSame(303, $response->getStatusCode());
+        self::assertStringStartsWith('text/html', $response->headers->get('Content-Type'));
+    }
+
+    public function testAuthenticatedCookieAccessAfterLogin(): void {
+        $client = static::createClient();
+
+        // login
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'dave',
+                'token' => $this->validTotpCode(),
+                'nonce' => $nonce,
+                'json'  => true,
+            ]),
+        ]);
+
+        // grab the cookie value from the login response
+        $loginResponse = $client->getResponse();
+        $cookieValue = null;
+        foreach ($loginResponse->headers->getCookies() as $cookie) {
+            if (str_contains($cookie->getName(), 'Preauth')) {
+                $cookieValue = $cookie->getValue();
+            }
+        }
+        self::assertNotNull($cookieValue);
+
+        // the cookie was set with secure=true, so the CookieJar will only
+        // send it over HTTPS; the KernelBrowser automatically updates the
+        // CookieJar from the login response, so the next request over HTTPS
+        // will include it
+        $client->request('GET', 'https://localhost/dashboard');
+
+        $response = $client->getResponse();
+        self::assertSame(200, $response->getStatusCode());
+        self::assertSame('dave', $response->headers->get('Remote-User'));
+    }
+
+    public function testScopeNoneReturnsPlainTextWithoutRedirect(): void {
+        $client = static::createClient();
+
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'eve',
+                'token' => $this->validTotpCode(),
+                'nonce' => $nonce,
+                'scope' => 'none',
+            ]),
+        ]);
+
+        $response = $client->getResponse();
+        self::assertSame(200, $response->getStatusCode());
+        self::assertStringStartsWith('text/plain', $response->headers->get('Content-Type'));
+        self::assertSame('eve', $response->headers->get('Remote-User'));
+        // no redirect for scope=none
+        self::assertFalse($response->headers->has('Location'));
+    }
+
+    /* ── failed login ─────────────────────────────────────────────────── */
+
+    public function testFailedLoginReturnsUnauthorizedJsonWithError(): void {
+        $client = static::createClient();
+
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'alice',
+                'token' => '000000', // wrong code
+                'nonce' => $nonce,
+                'json'  => true,
+            ]),
+        ]);
+
+        $response = $client->getResponse();
+        self::assertSame(401, $response->getStatusCode());
+        self::assertSame('application/json', $response->headers->get('Content-Type'));
+        $body = json_decode($response->getContent(), true);
+        self::assertArrayHasKey('message', $body);
+        self::assertArrayHasKey('nonce', $body);
+        // a fresh nonce should be returned for the next attempt
+        self::assertNotEmpty($body['nonce']);
+    }
+
+    public function testFailedLoginReturnsHtmlWhenJsonFalse(): void {
+        $client = static::createClient();
+
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'alice',
+                'token' => 'wrong-code',
+                'nonce' => $nonce,
+                'json'  => false,
+            ]),
+        ]);
+
+        $response = $client->getResponse();
+        self::assertSame(401, $response->getStatusCode());
+        self::assertStringStartsWith('text/html', $response->headers->get('Content-Type'));
+        self::assertSelectorExists('form#preauth-form');
+    }
+
+    public function testFailedLoginWithSpentNonceIsRejected(): void {
+        $client = static::createClient();
+
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        // first: successful login consumes the nonce
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'alice',
+                'token' => $this->validTotpCode(),
+                'nonce' => $nonce,
+                'json'  => true,
+            ]),
+        ]);
+        self::assertSame(303, $client->getResponse()->getStatusCode());
+
+        // the successful login set a session cookie; clear it so the next
+        // request is not auto-authenticated by AcceptListener before the
+        // login attempt is even evaluated
+        $client->getCookieJar()->clear();
+
+        // reuse the same nonce — should fail even with a valid token
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'alice',
+                'token' => $this->validTotpCode(),
+                'nonce' => $nonce,
+                'json'  => true,
+            ]),
+        ]);
+        self::assertSame(401, $client->getResponse()->getStatusCode());
+    }
+
+    public function testFailedLoginWithInvalidNonceIsRejected(): void {
+        $client = static::createClient();
+
+        // skip fetching a real nonce; use one that was never stored
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'alice',
+                'token' => $this->validTotpCode(),
+                'nonce' => 'never-issued-nonce',
+                'json'  => true,
+            ]),
+        ]);
+
+        self::assertSame(401, $client->getResponse()->getStatusCode());
+    }
+
+    /* ── invalid payload ──────────────────────────────────────────────── */
+
+    public function testInvalidHeaderPayloadReturnsUnauthorized(): void {
+        $client = static::createClient();
+
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => '!!!not-valid-base64!!!',
+        ]);
+
+        // decode fails -> null payload -> failure path -> 401
+        self::assertSame(401, $client->getResponse()->getStatusCode());
+    }
+
+    public function testPayloadWithMissingFieldsReturnsUnauthorized(): void {
+        $client = static::createClient();
+
+        // payload missing token
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id' => 'alice', 'nonce' => 'some-nonce',
+            ]),
+        ]);
+
+        self::assertSame(401, $client->getResponse()->getStatusCode());
+    }
+
+    /* ── invalid cookie ───────────────────────────────────────────────── */
+
+    public function testInvalidCookieIsClearedAndLoginPageShown(): void {
+        $client = static::createClient();
+
+        // the cookie must be set via the CookieJar so that the HttpFoundation
+        // Request actually populates its cookies bag (HTTP_COOKIE alone is
+        // not parsed by Request::create)
+        $client->getCookieJar()->set(
+            new \Symfony\Component\BrowserKit\Cookie(
+                self::COOKIE_NAME, 'invalid-ulid-value',
+                null, '/', 'localhost', true, true, false, 'Strict',
+            )
+        );
+
+        $client->request('GET', 'https://localhost/');
+
+        $response = $client->getResponse();
+        // not authenticated -> login page with 401
+        self::assertSame(401, $response->getStatusCode());
+        // the stale cookie should be cleared
+        $cleared = false;
+        foreach ($response->headers->getCookies() as $cookie) {
+            if ($cookie->getName() === self::COOKIE_NAME && $cookie->isCleared()) {
+                $cleared = true;
+            }
+        }
+        self::assertTrue($cleared, 'Expected the invalid cookie to be cleared');
+    }
+
+    /* ── backup code authentication ───────────────────────────────────── */
+
+    public function testBackupCodeAuthenticationWorks(): void {
+        $client = static::createClient();
+        $container = $client->getContainer();
+
+        // generate a backup code via the BackupCodeManager
+        $manager = $container->get(\App\Service\BackupCodeInterface::class);
+        $codes = $manager->generate(1);
+        self::assertCount(1, $codes);
+
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id'    => 'frank',
+                'token' => $codes[0],
+                'nonce' => $nonce,
+                'json'  => true,
+            ]),
+        ]);
+
+        self::assertSame(303, $client->getResponse()->getStatusCode());
+    }
+
+    public function testConsumedBackupCodeCannotBeReused(): void {
+        $client = static::createClient();
+        $container = $client->getContainer();
+
+        $manager = $container->get(\App\Service\BackupCodeInterface::class);
+        $codes = $manager->generate(1);
+        $code = $codes[0];
+
+        // first use
+        $crawler = $client->request('GET', '/');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id' => 'frank', 'token' => $code, 'nonce' => $nonce, 'json' => true,
+            ]),
+        ]);
+        self::assertSame(303, $client->getResponse()->getStatusCode());
+
+        // the successful login set a session cookie; clear it so the next
+        // request reaches the login page instead of being auto-authenticated
+        $client->getCookieJar()->clear();
+
+        // second use with a fresh nonce
+        $crawler = $client->request('GET', '/');
+        $nonce2 = $crawler->filter('input[name="nonce"]')->attr('value');
+        $client->request('GET', '/', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id' => 'frank', 'token' => $code, 'nonce' => $nonce2, 'json' => true,
+            ]),
+        ]);
+        self::assertSame(401, $client->getResponse()->getStatusCode());
+    }
+
+    /* ── return URL handling ──────────────────────────────────────────── */
+
+    public function testSuccessfulLoginWithValidReturnUrl(): void {
+        $client = static::createClient();
+
+        $crawler = $client->request('GET', '/?return=https://example.com/app');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/?return=https://example.com/app', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id' => 'alice', 'token' => $this->validTotpCode(),
+                'nonce' => $nonce, 'json' => true,
+            ]),
+        ]);
+
+        $response = $client->getResponse();
+        self::assertSame(303, $response->getStatusCode());
+        self::assertSame('https://example.com/app', $response->headers->get('Location'));
+    }
+
+    public function testSuccessfulLoginWithInvalidReturnFallsBackToPath(): void {
+        $client = static::createClient();
+
+        $crawler = $client->request('GET', '/?return=not-a-url');
+        $nonce = $crawler->filter('input[name="nonce"]')->attr('value');
+
+        $client->request('GET', '/?return=not-a-url', [], [], [
+            'HTTP_X-Preauth' => $this->encodePayload([
+                'id' => 'alice', 'token' => $this->validTotpCode(),
+                'nonce' => $nonce, 'json' => true,
+            ]),
+        ]);
+
+        $response = $client->getResponse();
+        self::assertSame(303, $response->getStatusCode());
+        $location = $response->headers->get('Location');
+        // should fall back to the request path (with query string),
+        // not redirect to the invalid return URL as an absolute URL
+        self::assertStringStartsWith('/', $location);
+        // the invalid return URL is not used as the redirect target
+        self::assertStringNotContainsString('//not-a-url', $location);
+    }
+}

tests/Support/ListenerTestHelper.php

@@ -0,0 +1,111 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Support;
+
+use App\ConfigBag;
+use App\Service\DomainManager;
+use Psr\Log\NullLogger;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\RateLimiter\RateLimit;
+use Symfony\Component\RateLimiter\RateLimiterFactoryInterface;
+use Symfony\Component\RateLimiter\LimiterInterface;
+use Twig\Environment;
+use Twig\Loader\FilesystemLoader;
+
+/**
+ * Helpers for constructing the collaborators that the kernel listeners
+ * depend on, without booting the full Symfony container.
+ */
+trait ListenerTestHelper {
+    use TotpTestHelper;
+
+    /** Build a Twig Environment pointed at the project's real templates. */
+    private function makeTwig(): Environment {
+        $loader = new FilesystemLoader(dirname(__DIR__, 2) . '/templates');
+        $twig = new Environment($loader, ['strict_variables' => true]);
+        // the templates reference a global `env` object; supply one with the
+        // keys used by base/login/error/_script/_style
+        $twig->addGlobal('env', (object)[
+            'title'            => 'Pre-Authentication System',
+            'bg_color'         => '#029386',
+            'fg_color'         => '#ffffff',
+            'error_color'      => '#ffb16d',
+            'id_name'          => 'Session ID',
+            'token_name'       => 'Authentication Token',
+            'submit_name'      => 'Submit',
+            'error_message'    => 'Unsuccessful login attempt',
+            'teapot'           => true,
+            'teapot_title'     => "I'm a teapot",
+            'teapot_message'   => 'I refuse to brew coffee',
+            'too_many_title'   => 'Too many requests',
+            'too_many_message' => 'Try again later',
+            'debug'            => 0,
+        ]);
+        return $twig;
+    }
+
+    /**
+     * A RateLimiterFactoryInterface whose created limiter returns a RateLimit
+     * with the given remaining tokens.
+     */
+    private function makeRateLimiterFactory(int $remainingTokens): RateLimiterFactoryInterface {
+        $limiter = $this->makeLimiter($remainingTokens);
+        return new class($limiter) implements RateLimiterFactoryInterface {
+            public function __construct(private LimiterInterface $limiter) {}
+            public function create(?string $key = null): LimiterInterface {
+                return $this->limiter;
+            }
+        };
+    }
+
+    private function makeLimiter(int $remainingTokens): LimiterInterface {
+        $rateLimit = new RateLimit(
+            $remainingTokens,
+            new \DateTimeImmutable('+10 seconds'),
+            $remainingTokens > 0,
+            10,
+        );
+        return new class($rateLimit) implements LimiterInterface {
+            public function __construct(private RateLimit $rateLimit) {}
+            public function reserve(int $tokens = 1, ?float $maxTime = null): \Symfony\Component\RateLimiter\Reservation {
+                throw new \Symfony\Component\RateLimiter\Exception\ReserveNotSupportedException();
+            }
+            public function consume(int $tokens = 1): RateLimit {
+                return $this->rateLimit;
+            }
+            public function reset(): void {}
+        };
+    }
+
+    /**
+     * A factory whose limiter tracks how many consume(1) calls were made and
+     * reports the limit as reached only after $threshold failures.
+     */
+    private function makeCountingRateLimiterFactory(int $threshold): RateLimiterFactoryInterface {
+        $limiter = new class($threshold) implements LimiterInterface {
+            private int $consumed = 0;
+            public function __construct(private int $threshold) {}
+            public function reserve(int $tokens = 1, ?float $maxTime = null): \Symfony\Component\RateLimiter\Reservation {
+                throw new \Symfony\Component\RateLimiter\Exception\ReserveNotSupportedException();
+            }
+            public function consume(int $tokens = 1): RateLimit {
+                $this->consumed += $tokens;
+                $remaining = max(0, $this->threshold - $this->consumed);
+                return new RateLimit(
+                    $remaining,
+                    new \DateTimeImmutable('+10 seconds'),
+                    $remaining > 0,
+                    $this->threshold,
+                );
+            }
+            public function reset(): void { $this->consumed = 0; }
+        };
+        return new class($limiter) implements RateLimiterFactoryInterface {
+            public function __construct(private LimiterInterface $limiter) {}
+            public function create(?string $key = null): LimiterInterface {
+                return $this->limiter;
+            }
+        };
+    }
+}

tests/Support/TotpTestHelper.php

@@ -0,0 +1,89 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Support;
+
+use App\ConfigBag;
+use App\Utilities;
+use DateTimeImmutable;
+use OTPHP\TOTP;
+use PHPUnit\Framework\TestCase;
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Clock\ClockInterface as PsrClockInterface;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+
+/**
+ * Provides a deterministic TOTP fixture plus a frozen clock and ready-made
+ * ConfigBag / cache-pool helpers for tests that exercise TOTP-dependent code.
+ */
+trait TotpTestHelper {
+    /** well-known Base32 test secret (JBSWY3DPEHPK3PXP) */
+    private const string TOTP_SECRET = 'JBSWY3DPEHPK3PXP';
+
+    /** Frozen timestamp used for deterministic TOTP codes. */
+    protected const string FROZEN_TIME = '2025-06-15 12:00:00';
+
+    /** Frozen clock that always returns the same instant. */
+    private function frozenClock(): PsrClockInterface {
+        $time = self::FROZEN_TIME;
+        return new class($time) implements PsrClockInterface {
+            public function __construct(private string $time) {}
+            public function now(): DateTimeImmutable {
+                return new DateTimeImmutable($this->time);
+            }
+        };
+    }
+
+    /** Provisioning URI built from the well-known secret + frozen clock. */
+    private function totpUri(): string {
+        $totp = TOTP::createFromSecret(self::TOTP_SECRET, $this->frozenClock());
+        $totp->setLabel('Test-TOTP');
+        return $totp->getProvisioningUri();
+    }
+
+    /** The TOTP code that is valid at the frozen timestamp. */
+    private function validTotpCode(): string {
+        return TOTP::createFromSecret(self::TOTP_SECRET, $this->frozenClock())->now();
+    }
+
+    /** A fresh in-memory cache pool suitable for wrapping in MonitorCacheKeys. */
+    private function emptyPool(): CacheItemPoolInterface {
+        return new ArrayAdapter();
+    }
+
+    /**
+     * Build a ConfigBag wired with the deterministic TOTP and frozen clock.
+     * Extra params override the sensible defaults.
+     */
+    private function makeConfig(
+        ?int $cookieTtl = 3600,
+        ?int $ipTtl = 0,
+        bool $teapot = true,
+        string $errorMessage = 'Error',
+        string $teapotTitle = 'Teapot',
+        string $tooManyTitle = 'Too Many',
+    ): ConfigBag {
+        $clock = $this->frozenClock();
+        $utilities = $this->createUtilities($clock);
+        return new ConfigBag(
+            $utilities, $clock,
+            $cookieTtl, $this->totpUri(), $ipTtl, $teapot,
+            $errorMessage, $teapotTitle, $tooManyTitle,
+        );
+    }
+
+    /**
+     * Minimal Utilities stub that never triggers TOTP generation when
+     * a non-empty totpUri is supplied to ConfigBag.
+     */
+    private function createUtilities(?PsrClockInterface $clock = null): Utilities {
+        $clock ??= $this->frozenClock();
+        $cache = $this->createStub(CacheItemPoolInterface::class);
+        $cache->method('hasItem')->willReturn(false);
+        $item = $this->createStub(CacheItemInterface::class);
+        $item->method('isHit')->willReturn(false);
+        $cache->method('getItem')->willReturn($item);
+        return new Utilities($clock, $cache);
+    }
+}

tests/TestKernel.php

@@ -0,0 +1,41 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests;
+
+use App\Kernel as AppKernel;
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+/**
+ * Kernel used by the functional test suite.
+ *
+ * In production the nonce cache is backed by APCu, which naturally persists
+ * across PHP requests.  In the test environment the nonce cache is an
+ * in-memory ArrayAdapter; Symfony's ServicesResetter clears it between
+ * requests (even with KernelBrowser::disableReboot()), which would discard
+ * the nonce issued on the login-page request before the login-submission
+ * request can verify it.
+ *
+ * This kernel removes the kernel.reset tag from the nonceCache (and
+ * rateLimitCache) pools so their in-memory state survives across requests
+ * within a single test, mirroring the persistence behaviour of APCu.
+ */
+class TestKernel extends AppKernel
+{
+    protected function build(ContainerBuilder $container): void
+    {
+        parent::build($container);
+
+        $container->addCompilerPass(new class implements CompilerPassInterface {
+            public function process(ContainerBuilder $container): void
+            {
+                foreach (['nonceCache', 'rateLimitCache', 'sessionCache', 'sessionStorage'] as $poolId) {
+                    if ($container->hasDefinition($poolId)) {
+                        $container->getDefinition($poolId)->clearTag('kernel.reset');
+                    }
+                }
+            }
+        });
+    }
+}

tests/Unit/ClockTest.php

@@ -0,0 +1,20 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit;
+
+use App\Clock;
+use PHPUnit\Framework\TestCase;
+
+final class ClockTest extends TestCase {
+    public function testNowReturnsDateTimeImmutable(): void {
+        $clock = new Clock();
+        $before = new \DateTimeImmutable();
+        $now = $clock->now();
+        $after = new \DateTimeImmutable();
+
+        self::assertInstanceOf(\DateTimeImmutable::class, $now);
+        self::assertGreaterThanOrEqual($before->getTimestamp(), $now->getTimestamp());
+        self::assertLessThanOrEqual($after->getTimestamp(), $now->getTimestamp());
+    }
+}

tests/Unit/Command/GenerateBackupCodesCommandTest.php

@@ -0,0 +1,120 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Command;
+
+use App\Command\GenerateBackupCodesCommand;
+use App\PersistCache;
+use App\Service\BackupCodeInterface;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\Console\Tester\CommandTester;
+
+final class GenerateBackupCodesCommandTest extends TestCase {
+
+    /** PersistCache is final, so construct a real one backed by ArrayAdapters. */
+    private function makePersistCache(): PersistCache {
+        return new PersistCache(new ArrayAdapter(), new ArrayAdapter());
+    }
+
+    /** A stub BackupCodeInterface that returns the given codes from generate(). */
+    private function makeManagerStub(array $generatedCodes): BackupCodeInterface {
+        $manager = $this->createStub(BackupCodeInterface::class);
+        $manager->method('generate')->willReturn($generatedCodes);
+        return $manager;
+    }
+
+    public function testGenerateDefaultCountOutputsCodes(): void {
+        $codes = ['abc123', 'def456', 'ghi789', 'jkl012', 'mno345',
+                  'pqr678', 'stu901', 'vwx234', 'yzA567', 'bCd890'];
+        $command = new GenerateBackupCodesCommand(
+            $this->makeManagerStub($codes), $this->makePersistCache()
+        );
+        $command->setName('app:generate-backup-codes');
+
+        $tester = new CommandTester($command);
+        $exit = $tester->execute([]);
+
+        self::assertSame(0, $exit);
+        $output = $tester->getDisplay();
+        foreach ($codes as $code) {
+            self::assertStringContainsString($code, $output);
+        }
+    }
+
+    public function testGenerateSpecificCountPassesCountToManager(): void {
+        $manager = $this->createMock(BackupCodeInterface::class);
+        $manager->expects(self::once())
+            ->method('generate')
+            ->with(self::identicalTo(5))
+            ->willReturn(['c1', 'c2', 'c3', 'c4', 'c5']);
+
+        $command = new GenerateBackupCodesCommand($manager, $this->makePersistCache());
+        $command->setName('app:generate-backup-codes');
+
+        $tester = new CommandTester($command);
+        $exit = $tester->execute(['count' => 5]);
+
+        self::assertSame(0, $exit);
+    }
+
+    public function testDefaultCountArgumentIsTen(): void {
+        // the configured default for the count argument should be 10
+        $manager = $this->createMock(BackupCodeInterface::class);
+        $manager->expects(self::once())
+            ->method('generate')
+            ->with(self::identicalTo(10))
+            ->willReturn(array_fill(0, 10, 'code'));
+
+        $command = new GenerateBackupCodesCommand($manager, $this->makePersistCache());
+        $command->setName('app:generate-backup-codes');
+
+        $tester = new CommandTester($command);
+        $tester->execute([]);
+
+        // assertion is in the mock expectation above
+        $this->addToAssertionCount(1);
+    }
+
+    public function testBootsAndPersistsCache(): void {
+        // PersistCache is final and can't be mocked, but we can verify the
+        // command runs end-to-end with a real instance; boot()/persist()
+        // are invoked implicitly. A successful exit confirms both were called
+        // without throwing.
+        $command = new GenerateBackupCodesCommand(
+            $this->makeManagerStub(['code1']), $this->makePersistCache()
+        );
+        $command->setName('app:generate-backup-codes');
+
+        $tester = new CommandTester($command);
+        $exit = $tester->execute([]);
+
+        self::assertSame(0, $exit);
+    }
+
+    public function testZeroCodesOutputsNothing(): void {
+        $command = new GenerateBackupCodesCommand(
+            $this->makeManagerStub([]), $this->makePersistCache()
+        );
+        $command->setName('app:generate-backup-codes');
+
+        $tester = new CommandTester($command);
+        $exit = $tester->execute(['count' => 0]);
+
+        self::assertSame(0, $exit);
+        self::assertSame('', trim($tester->getDisplay()));
+    }
+
+    public function testCommandNameAndDescriptionAreConfigured(): void {
+        $command = new GenerateBackupCodesCommand(
+            $this->makeManagerStub([]), $this->makePersistCache()
+        );
+        // configuring via the Application runs the protected configure()
+        $app = new \Symfony\Component\Console\Application();
+        $app->addCommand($command);
+        self::assertSame('app:generate-backup-codes', $command->getName());
+        // the source uses a non-breaking hyphen (U+2011) in "single‑use",
+        // so assert against the substring to avoid encoding fragility
+        self::assertStringContainsString('backup codes', $command->getDescription());
+    }
+}

tests/Unit/ConfigBagTest.php

@@ -0,0 +1,90 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit;
+
+use App\ConfigBag;
+use App\Utilities;
+use PHPUnit\Framework\TestCase;
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Clock\ClockInterface;
+
+final class ConfigBagTest extends TestCase {
+    private function createUtilities(?string $totp = null): Utilities {
+        $clock = $this->createStub(ClockInterface::class);
+        $cache = $this->createStub(CacheItemPoolInterface::class);
+
+        if ($totp !== null) {
+            $item = $this->createStub(CacheItemInterface::class);
+            $item->method('isHit')->willReturn(true);
+            $item->method('get')->willReturn($totp);
+            $cache->method('hasItem')->willReturn(true);
+            $cache->method('getItem')->willReturn($item);
+        } else {
+            $cache->method('hasItem')->willReturn(false);
+        }
+
+        return new Utilities($clock, $cache);
+    }
+
+    public function testGettersWithExplicitValues(): void {
+        $clock = $this->createStub(ClockInterface::class);
+        $utilities = $this->createUtilities();
+
+        $config = new ConfigBag(
+            $utilities, $clock,
+            3600, 'otpauth://totp/test', 1800, true,
+            'Error!', 'Teapot!', 'Too Many!'
+        );
+
+        self::assertSame($clock, $config->clock());
+        self::assertSame(3600, $config->cookieTtl());
+        self::assertSame('otpauth://totp/test', $config->totpUri());
+        self::assertSame(1800, $config->ipTtl());
+        self::assertTrue($config->teapot());
+        self::assertSame('Error!', $config->errorMessage());
+        self::assertSame('Teapot!', $config->teapotTitle());
+        self::assertSame('Too Many!', $config->tooManyTitle());
+    }
+
+    public function testTotpUriFallsBackToUtilitiesWhenEmpty(): void {
+        $clock = $this->createStub(ClockInterface::class);
+        $utilities = $this->createUtilities('fallback-totp');
+
+        $config = new ConfigBag(
+            $utilities, $clock,
+            3600, '', 1800, false,
+            'Error', 'Teapot', 'Too Many'
+        );
+
+        self::assertSame('fallback-totp', $config->totpUri());
+    }
+
+    public function testIpTtlFallsBackToNullWhenZero(): void {
+        $clock = $this->createStub(ClockInterface::class);
+        $utilities = $this->createUtilities();
+
+        $config = new ConfigBag(
+            $utilities, $clock,
+            3600, 'otpauth://totp/test', 0, false,
+            'Error', 'Teapot', 'Too Many'
+        );
+
+        self::assertNull($config->ipTtl());
+    }
+
+    public function testIpTtlFallsBackToNullWhenNull(): void {
+        $clock = $this->createStub(ClockInterface::class);
+        $utilities = $this->createUtilities();
+
+        $config = new ConfigBag(
+            $utilities, $clock,
+            3600, 'otpauth://totp/test', null, false,
+            'Error', 'Teapot', 'Too Many'
+        );
+
+        self::assertNull($config->ipTtl());
+    }
+}
+

tests/Unit/Data/PayloadTest.php

@@ -0,0 +1,195 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Data;
+
+use App\Data\Payload;
+use App\Enum\Scope;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpFoundation\InputBag;
+
+final class PayloadTest extends TestCase {
+    private static function b64u(string $data): string {
+        return rtrim(strtr(base64_encode($data), '+/', '-_'), '=');
+    }
+
+    public function testDecodeValidBase64Url(): void {
+        $data = json_encode([
+            'id' => 'testuser', 'token' => '123456', 'nonce' => 'abc123',
+            'json' => true, 'scope' => 'cookie',
+        ]);
+        $payload = Payload::decode(self::b64u($data));
+
+        self::assertInstanceOf(Payload::class, $payload);
+        self::assertSame('testuser', $payload->id);
+        self::assertSame('123456', $payload->token);
+        self::assertSame('abc123', $payload->nonce);
+        self::assertTrue($payload->json);
+        self::assertSame(Scope::Cookie, $payload->scope);
+    }
+
+    public function testDecodeInvalidBase64UrlReturnsNull(): void {
+        self::assertNull(Payload::decode('!!!not-valid-base64!!!'));
+    }
+
+    public function testDecodeNonObjectJsonReturnsNull(): void {
+        self::assertNull(Payload::decode(self::b64u('"just a string"')));
+    }
+
+    public function testDecodeInvalidJsonReturnsNull(): void {
+        // valid base64url but invalid JSON
+        self::assertNull(Payload::decode(self::b64u('{invalid json')));
+    }
+
+    public function testDecodeJsonArrayReturnsNull(): void {
+        self::assertNull(Payload::decode(self::b64u('[1,2,3]')));
+    }
+
+    public function testDecodeJsonNullReturnsNull(): void {
+        self::assertNull(Payload::decode(self::b64u('null')));
+    }
+
+    public function testDecodeJsonBooleanReturnsNull(): void {
+        self::assertNull(Payload::decode(self::b64u('true')));
+        self::assertNull(Payload::decode(self::b64u('false')));
+    }
+
+    public function testDecodeJsonNumberReturnsNull(): void {
+        self::assertNull(Payload::decode(self::b64u('42')));
+    }
+
+    public function testDecodeEmptyStringReturnsNull(): void {
+        self::assertNull(Payload::decode(''));
+    }
+
+    public function testLoadWithValidInputBag(): void {
+        $input = new InputBag([
+            'username' => 'alice', 'nonce' => 'nonce123', 'totp' => '654321',
+        ]);
+        $payload = Payload::load($input);
+
+        self::assertInstanceOf(Payload::class, $payload);
+        self::assertSame('alice', $payload->id);
+        self::assertSame('nonce123', $payload->nonce);
+        self::assertSame('654321', $payload->token);
+        self::assertFalse($payload->json);
+        self::assertSame(Scope::Cookie, $payload->scope);
+    }
+
+    public function testLoadMissingUsernameReturnsNull(): void {
+        $input = new InputBag(['nonce' => 'n', 'totp' => 't']);
+        self::assertNull(Payload::load($input));
+    }
+
+    public function testLoadMissingNonceReturnsNull(): void {
+        $input = new InputBag(['username' => 'u', 'totp' => 't']);
+        self::assertNull(Payload::load($input));
+    }
+
+    public function testLoadMissingTotpReturnsNull(): void {
+        $input = new InputBag(['username' => 'u', 'nonce' => 'n']);
+        self::assertNull(Payload::load($input));
+    }
+
+    public function testLoadWithAllFieldsPresentButEmptyReturnsNull(): void {
+        // has() returns true for all, but create() rejects empty values
+        $input = new InputBag(['username' => '', 'nonce' => '', 'totp' => '']);
+        self::assertNull(Payload::load($input));
+    }
+
+    public function testCreateWithValidData(): void {
+        $data = (object)[
+            'id' => 'user1', 'token' => 'tok1', 'nonce' => 'non1',
+            'json' => false, 'scope' => 'ip',
+        ];
+        $payload = Payload::create($data);
+
+        self::assertInstanceOf(Payload::class, $payload);
+        self::assertSame('user1', $payload->id);
+        self::assertSame('tok1', $payload->token);
+        self::assertSame('non1', $payload->nonce);
+        self::assertFalse($payload->json);
+        self::assertSame(Scope::Ip, $payload->scope);
+    }
+
+    public function testCreateWithDefaultScope(): void {
+        $data = (object)['id' => 'user1', 'token' => 'tok1', 'nonce' => 'non1'];
+        $payload = Payload::create($data);
+        self::assertSame(Scope::Cookie, $payload->scope);
+    }
+
+    public function testCreateWithInvalidScopeFallsBackToCookie(): void {
+        $data = (object)[
+            'id' => 'user1', 'token' => 'tok1', 'nonce' => 'non1',
+            'scope' => 'admin',
+        ];
+        $payload = Payload::create($data);
+        self::assertSame(Scope::Cookie, $payload->scope);
+    }
+
+    public function testCreateWithMissingJsonDefaultsToTrue(): void {
+        $data = (object)['id' => 'user1', 'token' => 'tok1', 'nonce' => 'non1'];
+        $payload = Payload::create($data);
+        self::assertTrue($payload->json);
+    }
+
+    public function testCreateWithNoneScopeSetsJsonFalse(): void {
+        $data = (object)[
+            'id' => 'user1', 'token' => 'tok1', 'nonce' => 'non1',
+            'json' => true, 'scope' => 'none',
+        ];
+        $payload = Payload::create($data);
+        self::assertSame(Scope::None, $payload->scope);
+        self::assertFalse($payload->json);
+    }
+
+    public function testCreateWithEmptyIdReturnsNull(): void {
+        $data = (object)['id' => '', 'token' => 't', 'nonce' => 'n'];
+        self::assertNull(Payload::create($data));
+    }
+
+    public function testCreateWithWhitespaceIdReturnsNull(): void {
+        $data = (object)['id' => '   ', 'token' => 't', 'nonce' => 'n'];
+        self::assertNull(Payload::create($data));
+    }
+
+    public function testCreateWithEmptyTokenReturnsNull(): void {
+        $data = (object)['id' => 'u', 'token' => '', 'nonce' => 'n'];
+        self::assertNull(Payload::create($data));
+    }
+
+    public function testCreateWithEmptyNonceReturnsNull(): void {
+        $data = (object)['id' => 'u', 'token' => 't', 'nonce' => ''];
+        self::assertNull(Payload::create($data));
+    }
+
+    public function testCreateTrimsAndTruncatesFields(): void {
+        $long = str_repeat('a', 200);
+        $data = (object)[
+            'id' => '  ' . $long . '  ',
+            'token' => '  ' . $long . '  ',
+            'nonce' => '  ' . $long . '  ',
+        ];
+        $payload = Payload::create($data);
+        $expected = mb_substr($long, 0, 128);
+        self::assertSame($expected, $payload->id);
+        self::assertSame($expected, $payload->token);
+        self::assertSame($expected, $payload->nonce);
+    }
+
+    public function testToString(): void {
+        $payload = new Payload();
+        $payload->id = 'u';
+        $payload->token = 't';
+        $payload->nonce = 'n';
+        $payload->json = true;
+        $payload->scope = Scope::Cookie;
+
+        $decoded = json_decode($payload->toString(), true);
+        self::assertSame('u', $decoded['id']);
+        self::assertSame('t', $decoded['token']);
+        self::assertSame('n', $decoded['nonce']);
+        self::assertTrue($decoded['json']);
+        self::assertSame('cookie', $decoded['scope']);
+    }
+}

tests/Unit/Enum/ScopeTest.php

@@ -0,0 +1,26 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Enum;
+
+use App\Enum\Scope;
+use PHPUnit\Framework\TestCase;
+
+final class ScopeTest extends TestCase {
+    public function testCases(): void {
+        self::assertSame('cookie', Scope::Cookie->value);
+        self::assertSame('ip', Scope::Ip->value);
+        self::assertSame('none', Scope::None->value);
+    }
+
+    public function testTryFromValid(): void {
+        self::assertSame(Scope::Cookie, Scope::tryFrom('cookie'));
+        self::assertSame(Scope::Ip, Scope::tryFrom('ip'));
+        self::assertSame(Scope::None, Scope::tryFrom('none'));
+    }
+
+    public function testTryFromInvalid(): void {
+        self::assertNull(Scope::tryFrom('invalid'));
+        self::assertNull(Scope::tryFrom(''));
+    }
+}

tests/Unit/Listener/AcceptListenerTest.php

@@ -0,0 +1,124 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Listener;
+
+use App\Listener\AcceptListener;
+use App\Service\DomainManager;
+use App\Tests\Support\TotpTestHelper;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\NullLogger;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+
+final class AcceptListenerTest extends TestCase {
+    use TotpTestHelper;
+
+    private const string COOKIE_NAME = '__Host-Http-Preauth';
+    private const string AUTH_COOKIE_NAME = '__Http-Domain-Preauth';
+
+    private function makeListener(ArrayAdapter $pool, DomainManager $domainManager): AcceptListener {
+        $listener = new AcceptListener($pool, $domainManager);
+        $listener->setLogger(new NullLogger());
+        return $listener;
+    }
+
+    private function makeEvent(Request $request): RequestEvent {
+        return new RequestEvent(
+            $this->createStub(\Symfony\Component\HttpKernel\HttpKernelInterface::class),
+            $request,
+            HttpKernelInterface::MAIN_REQUEST,
+        );
+    }
+
+    /* ── valid cookie session ─────────────────────────────────────────── */
+
+    public function testValidCookieSetsResponseWithRemoteUser(): void {
+        $pool = new ArrayAdapter();
+        $ulid = '01HXY1234567890ABCDEFGHIJK';
+        $item = $pool->getItem('cookie_' . $ulid);
+        $item->set('alice');
+        $pool->save($item);
+
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($pool, $domainManager);
+
+        $request = Request::create('/', 'GET');
+        $request->cookies->set(self::COOKIE_NAME, $ulid);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        self::assertSame(200, $response->getStatusCode());
+        self::assertSame('alice', $response->headers->get('Remote-User'));
+        self::assertSame('text/plain', $response->headers->get('Content-Type'));
+    }
+
+    public function testValidCookieUsesAuthCookieNameWhenUsingCentralAuth(): void {
+        $pool = new ArrayAdapter();
+        $ulid = '01HXY1234567890ABCDEFGHIJK';
+        $item = $pool->getItem('cookie_' . $ulid);
+        $item->set('bob');
+        $pool->save($item);
+
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener($pool, $domainManager);
+
+        $request = Request::create('/', 'GET');
+        $request->cookies->set(self::AUTH_COOKIE_NAME, $ulid);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        self::assertSame('bob', $event->getResponse()->headers->get('Remote-User'));
+    }
+
+    /* ── negative cases ───────────────────────────────────────────────── */
+
+    public function testNoCookieSetsNoResponse(): void {
+        $pool = new ArrayAdapter();
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($pool, $domainManager);
+
+        $event = $this->makeEvent(Request::create('/', 'GET'));
+        $listener->onKernelRequest($event);
+
+        self::assertFalse($event->hasResponse());
+    }
+
+    public function testCookieWithoutSessionSetsNoResponse(): void {
+        $pool = new ArrayAdapter();
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($pool, $domainManager);
+
+        $request = Request::create('/', 'GET');
+        $request->cookies->set(self::COOKIE_NAME, 'unknown-ulid');
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertFalse($event->hasResponse());
+    }
+
+    public function testEmptyCookieValueSetsNoResponse(): void {
+        $pool = new ArrayAdapter();
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($pool, $domainManager);
+
+        // cookies->set with empty string
+        $request = Request::create('/', 'GET');
+        $request->cookies->set(self::COOKIE_NAME, '');
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        // empty cookie value should not be treated as a valid session
+        self::assertFalse($event->hasResponse());
+    }
+}

tests/Unit/Listener/AllowListenerTest.php

@@ -0,0 +1,95 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Listener;
+
+use App\ConfigBag;
+use App\Listener\AllowListener;
+use App\Tests\Support\TotpTestHelper;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\NullLogger;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+
+final class AllowListenerTest extends TestCase {
+    use TotpTestHelper;
+
+    private function makeListener(ArrayAdapter $pool, ConfigBag $config): AllowListener {
+        $listener = new AllowListener($pool, $config);
+        $listener->setLogger(new NullLogger());
+        return $listener;
+    }
+
+    private function makeEvent(Request $request): RequestEvent {
+        return new RequestEvent(
+            $this->createStub(HttpKernelInterface::class),
+            $request,
+            HttpKernelInterface::MAIN_REQUEST,
+        );
+    }
+
+    public function testValidIpSessionSetsResponseWithRemoteUser(): void {
+        $pool = new ArrayAdapter();
+        $item = $pool->getItem('ip_1.2.3.4');
+        $item->set('carol');
+        $pool->save($item);
+
+        $config = $this->makeConfig(ipTtl: 1800);
+        $listener = $this->makeListener($pool, $config);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '1.2.3.4']);
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        self::assertSame(200, $response->getStatusCode());
+        self::assertSame('carol', $response->headers->get('Remote-User'));
+        self::assertSame('text/plain', $response->headers->get('Content-Type'));
+    }
+
+    public function testNoIpSessionSetsNoResponse(): void {
+        $pool = new ArrayAdapter();
+        $config = $this->makeConfig(ipTtl: 1800);
+        $listener = $this->makeListener($pool, $config);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '9.9.9.9']);
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertFalse($event->hasResponse());
+    }
+
+    public function testIpAccessDisabledSetsNoResponse(): void {
+        $pool = new ArrayAdapter();
+        // even though there's a stored session, ip access is disabled
+        $item = $pool->getItem('ip_1.2.3.4');
+        $item->set('carol');
+        $pool->save($item);
+
+        $config = $this->makeConfig(ipTtl: 0);
+        $listener = $this->makeListener($pool, $config);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '1.2.3.4']);
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertFalse($event->hasResponse());
+    }
+
+    public function testIpAccessDisabledDoesNotCheckCache(): void {
+        $pool = new ArrayAdapter();
+        $config = $this->makeConfig(ipTtl: 0);
+        $listener = $this->makeListener($pool, $config);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '1.2.3.4']);
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        // when disabled, nothing should have been written/read as a session
+        self::assertFalse($event->hasResponse());
+        self::assertFalse($pool->hasItem('ip_1.2.3.4'));
+    }
+}

tests/Unit/Listener/InterceptListenerTest.php

@@ -0,0 +1,206 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Listener;
+
+use App\Listener\InterceptListener;
+use App\Service\DomainManager;
+use App\Tests\Support\ListenerTestHelper;
+use PHPUnit\Framework\TestCase;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Log\NullLogger;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\HttpFoundation\Cookie;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+
+final class InterceptListenerTest extends TestCase {
+    use ListenerTestHelper;
+
+    private const string COOKIE_NAME = '__Host-Http-Preauth';
+    private const string AUTH_COOKIE_NAME = '__Http-Domain-Preauth';
+
+    private function makeListener(
+        DomainManager $domainManager,
+        ?CacheItemPoolInterface $nonceCache = null,
+    ): InterceptListener {
+        $listener = new InterceptListener(
+            $this->makeConfig(),
+            $domainManager,
+            $this->makeTwig(),
+        );
+        $listener->setLogger(new NullLogger());
+        $listener->setNonceCache($nonceCache ?? new ArrayAdapter());
+        return $listener;
+    }
+
+    private function makeEvent(Request $request): RequestEvent {
+        return new RequestEvent(
+            $this->createStub(HttpKernelInterface::class),
+            $request,
+            HttpKernelInterface::MAIN_REQUEST,
+        );
+    }
+
+    /* ── central-auth redirect branch ─────────────────────────────────── */
+
+    public function testRedirectsToAuthSubdomainWhenHostMatchesBaseDomain(): void {
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener($domainManager);
+
+        $request = Request::create('https://app.example.com/dashboard', 'GET');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        self::assertSame(Response::HTTP_SEE_OTHER, $response->getStatusCode());
+        $location = $response->headers->get('Location');
+        self::assertStringStartsWith('https://auth.example.com/?', $location);
+        // the return query should contain the original url
+        self::assertStringContainsString('return=', $location);
+        self::assertStringContainsString(urlencode('https://app.example.com/dashboard'), $location);
+    }
+
+    public function testDoesNotRedirectWhenAlreadyOnAuthSubdomain(): void {
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener($domainManager);
+
+        $request = Request::create('https://auth.example.com/', 'GET');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        // should render login page, not redirect
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        self::assertNotSame(Response::HTTP_SEE_OTHER, $response->getStatusCode());
+        self::assertSame(Response::HTTP_UNAUTHORIZED, $response->getStatusCode());
+    }
+
+    /* ── login page rendering branch ──────────────────────────────────── */
+
+    public function testPresentsLoginPageWithUnauthorizedStatus(): void {
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($domainManager);
+
+        $request = Request::create('https://example.com/', 'GET');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        self::assertSame(Response::HTTP_UNAUTHORIZED, $response->getStatusCode());
+        self::assertSame('text/html', $response->headers->get('Content-Type'));
+        $content = $response->getContent();
+        self::assertStringContainsString('<form', $content);
+        // the rendered page should embed a freshly generated nonce
+        self::assertStringContainsString('name="nonce"', $content);
+    }
+
+    public function testGeneratedNonceIsStoredInCache(): void {
+        $nonceCache = new ArrayAdapter();
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($domainManager, $nonceCache);
+
+        $request = Request::create('https://example.com/', 'GET');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        // exactly one nonce should now exist in the cache, marked valid
+        $found = false;
+        foreach ($nonceCache->getValues() as $key => $value) {
+            if (str_starts_with($key, 'test_') || preg_match('/^[A-Za-z0-9_.]+$/', $key)) {
+                $found = true;
+            }
+        }
+        // ArrayAdapter stores raw values; verify at least one item was saved
+        self::assertTrue(count($nonceCache->getValues()) > 0);
+    }
+
+    public function testLoginTemplateUsesPostFormWhenOnAuthSubdomain(): void {
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener($domainManager);
+
+        $request = Request::create('https://auth.example.com/', 'GET');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $content = $event->getResponse()->getContent();
+        // when on the auth subdomain, post=true so the form has method="post"
+        self::assertStringContainsString('method="post"', $content);
+    }
+
+    public function testLoginTemplateDoesNotUsePostFormWhenNotOnAuthSubdomain(): void {
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($domainManager);
+
+        $request = Request::create('https://example.com/', 'GET');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $content = $event->getResponse()->getContent();
+        // not on auth subdomain, so the form should NOT have method="post"
+        self::assertStringNotContainsString('method="post"', $content);
+    }
+
+    /* ── invalid cookie pruning ───────────────────────────────────────── */
+
+    public function testInvalidCookieIsClearedWhenPresent(): void {
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($domainManager);
+
+        $request = Request::create('https://example.com/', 'GET');
+        // send a cookie that won't match any session (so AcceptListener didn't fire)
+        $request->cookies->set(self::COOKIE_NAME, 'stale-ulid');
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        // a Clear-Site-Data style clearCookie should produce a Set-Cookie that expires it
+        $cookies = $response->headers->getCookies();
+        $cleared = false;
+        foreach ($cookies as $cookie) {
+            if ($cookie->getName() === self::COOKIE_NAME && $cookie->isCleared()) {
+                $cleared = true;
+            }
+        }
+        self::assertTrue($cleared, 'Expected the invalid cookie to be cleared');
+    }
+
+    public function testNoCookieClearingWhenNoCookiePresent(): void {
+        $domainManager = new DomainManager(false, '');
+        $listener = $this->makeListener($domainManager);
+
+        $request = Request::create('https://example.com/', 'GET');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $response = $event->getResponse();
+        self::assertSame([], $response->headers->getCookies());
+    }
+
+    public function testInvalidCookieUsesAuthCookieNameWithCentralAuth(): void {
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener($domainManager);
+
+        // request to auth subdomain with a stale auth-domain cookie
+        $request = Request::create('https://auth.example.com/', 'GET');
+        $request->cookies->set(self::AUTH_COOKIE_NAME, 'stale-ulid');
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $response = $event->getResponse();
+        $cleared = false;
+        foreach ($response->headers->getCookies() as $cookie) {
+            if ($cookie->getName() === self::AUTH_COOKIE_NAME && $cookie->isCleared()) {
+                $cleared = true;
+            }
+        }
+        self::assertTrue($cleared, 'Expected the auth cookie to be cleared');
+    }
+}

tests/Unit/Listener/LoginListenerTest.php

@@ -0,0 +1,295 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Listener;
+
+use App\Data\Payload;
+use App\Enum\Scope;
+use App\Listener\LoginListener;
+use App\Service\DomainManager;
+use App\Service\LoginInterface;
+use App\Tests\Support\ListenerTestHelper;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\NullLogger;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+
+final class LoginListenerTest extends TestCase {
+    use ListenerTestHelper;
+
+    private const string HEADER_NAME = 'X-Preauth';
+
+    private function makeListener(
+        ?LoginInterface $loginManager = null,
+        ?DomainManager $domainManager = null,
+        ?int $rateLimitRemaining = 5,
+    ): LoginListener {
+        $listener = new LoginListener(
+            $this->makeTwig(),
+            $this->makeRateLimiterFactory($rateLimitRemaining ?? 5),
+            $domainManager ?? new DomainManager(false, ''),
+            $loginManager ?? $this->createStub(LoginInterface::class),
+            $this->makeConfig(),
+        );
+        $listener->setLogger(new NullLogger());
+        $listener->setNonceCache(new ArrayAdapter());
+        return $listener;
+    }
+
+    private function makeEvent(Request $request): RequestEvent {
+        return new RequestEvent(
+            $this->createStub(HttpKernelInterface::class),
+            $request,
+            HttpKernelInterface::MAIN_REQUEST,
+        );
+    }
+
+    /** Build a base64url-encoded X-Preauth header value for a payload. */
+    private function encodePayload(array $data): string {
+        $json = json_encode($data, JSON_THROW_ON_ERROR);
+        return rtrim(strtr(base64_encode($json), '+/', '-_'), '=');
+    }
+
+    /* ── no login attempt ─────────────────────────────────────────────── */
+
+    public function testNoHeaderAndNoPostReturnsEarlyWithoutResponse(): void {
+        $listener = $this->makeListener();
+
+        $request = Request::create('https://example.com/', 'GET');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertFalse($event->hasResponse());
+    }
+
+    public function testPostToNonAuthSubdomainReturnsEarlyWithoutResponse(): void {
+        // POST only counts as a login attempt when on the auth subdomain
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener(domainManager: $domainManager);
+
+        $request = Request::create('https://app.example.com/', 'POST');
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertFalse($event->hasResponse());
+    }
+
+    /* ── successful login via header ──────────────────────────────────── */
+
+    public function testSuccessfulLoginViaHeaderSetsResponseFromManager(): void {
+        $expected = new Response('hi alice', 200, ['Remote-User' => 'alice']);
+        $loginManager = $this->createStub(LoginInterface::class);
+        $loginManager->method('checkToken')->willReturn($expected);
+
+        $listener = $this->makeListener(loginManager: $loginManager);
+
+        $payload = $this->encodePayload([
+            'id' => 'alice', 'token' => '123456', 'nonce' => 'nonce-1', 'json' => true,
+        ]);
+        $request = Request::create('https://example.com/', 'GET');
+        $request->headers->set(self::HEADER_NAME, $payload);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        self::assertSame($expected, $event->getResponse());
+    }
+
+    public function testSuccessfulLoginViaPostToAuthSubdomain(): void {
+        $expected = new Response('hi bob', 303, ['Location' => '/']);
+        $loginManager = $this->createStub(LoginInterface::class);
+        $loginManager->method('checkToken')->willReturn($expected);
+
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener(loginManager: $loginManager, domainManager: $domainManager);
+
+        $request = Request::create('https://auth.example.com/', 'POST', [
+            'username' => 'bob', 'totp' => '654321', 'nonce' => 'nonce-2',
+        ]);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        self::assertSame($expected, $event->getResponse());
+    }
+
+    /* ── failed login ─────────────────────────────────────────────────── */
+
+    public function testFailedLoginReturnsJsonErrorWithNewNonce(): void {
+        $loginManager = $this->createStub(LoginInterface::class);
+        $loginManager->method('checkToken')->willReturn(null);
+
+        $listener = $this->makeListener(loginManager: $loginManager);
+
+        $payload = $this->encodePayload([
+            'id' => 'alice', 'token' => 'wrong', 'nonce' => 'nonce-1', 'json' => true,
+        ]);
+        $request = Request::create('https://example.com/', 'GET');
+        $request->headers->set(self::HEADER_NAME, $payload);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        self::assertSame(Response::HTTP_UNAUTHORIZED, $response->getStatusCode());
+        self::assertSame('application/json', $response->headers->get('Content-Type'));
+        $body = json_decode($response->getContent(), true);
+        // the TotpTestHelper::makeConfig default errorMessage is 'Error'
+        self::assertSame('Error', $body['message']);
+        self::assertNotEmpty($body['nonce']);
+        self::assertFalse($body['post']);
+        // username is echoed back (sanitized via makeCacheKey)
+        self::assertSame('alice', $body['username']);
+    }
+
+    public function testFailedLoginHtmlResponseWhenJsonFalse(): void {
+        $loginManager = $this->createStub(LoginInterface::class);
+        $loginManager->method('checkToken')->willReturn(null);
+
+        $listener = $this->makeListener(loginManager: $loginManager);
+
+        $payload = $this->encodePayload([
+            'id' => 'alice', 'token' => 'wrong', 'nonce' => 'nonce-1', 'json' => false,
+        ]);
+        $request = Request::create('https://example.com/', 'GET');
+        $request->headers->set(self::HEADER_NAME, $payload);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $response = $event->getResponse();
+        self::assertSame(Response::HTTP_UNAUTHORIZED, $response->getStatusCode());
+        self::assertSame('text/html', $response->headers->get('Content-Type'));
+        self::assertStringContainsString('<form', $response->getContent());
+    }
+
+    public function testFailedLoginOnAuthSubdomainUsesPostForm(): void {
+        $loginManager = $this->createStub(LoginInterface::class);
+        $loginManager->method('checkToken')->willReturn(null);
+
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener(
+            loginManager: $loginManager,
+            domainManager: $domainManager,
+        );
+
+        $payload = $this->encodePayload([
+            'id' => 'alice', 'token' => 'wrong', 'nonce' => 'nonce-1', 'json' => false,
+        ]);
+        $request = Request::create('https://auth.example.com/', 'GET');
+        $request->headers->set(self::HEADER_NAME, $payload);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $content = $event->getResponse()->getContent();
+        self::assertStringContainsString('method="post"', $content);
+    }
+
+    /* ── rate-limited (blocked) login ─────────────────────────────────── */
+
+    public function testRateLimitedLoginReturnsTeapotWhenTeapotEnabled(): void {
+        $loginManager = $this->createStub(LoginInterface::class);
+        $loginManager->method('checkToken')->willReturn(null);
+
+        // limiter with 0 remaining tokens -> blocked
+        $listener = $this->makeListener(
+            loginManager: $loginManager,
+            rateLimitRemaining: 0,
+        );
+
+        $payload = $this->encodePayload([
+            'id' => 'alice', 'token' => 'wrong', 'nonce' => 'nonce-1', 'json' => true,
+        ]);
+        $request = Request::create('https://example.com/', 'GET');
+        $request->headers->set(self::HEADER_NAME, $payload);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $response = $event->getResponse();
+        self::assertSame(Response::HTTP_I_AM_A_TEAPOT, $response->getStatusCode());
+        $body = json_decode($response->getContent(), true);
+        // the TotpTestHelper::makeConfig default teapotTitle is 'Teapot'
+        self::assertSame('Teapot', $body['message']);
+    }
+
+    public function testRateLimitedLoginReturnsTooManyRequestsWhenTeapotDisabled(): void {
+        $loginManager = $this->createStub(LoginInterface::class);
+        $loginManager->method('checkToken')->willReturn(null);
+
+        $listener = new LoginListener(
+            $this->makeTwig(),
+            $this->makeRateLimiterFactory(0),
+            new DomainManager(false, ''),
+            $loginManager,
+            $this->makeConfig(teapot: false),
+        );
+        $listener->setLogger(new NullLogger());
+        $listener->setNonceCache(new ArrayAdapter());
+
+        $payload = $this->encodePayload([
+            'id' => 'alice', 'token' => 'wrong', 'nonce' => 'nonce-1', 'json' => true,
+        ]);
+        $request = Request::create('https://example.com/', 'GET');
+        $request->headers->set(self::HEADER_NAME, $payload);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $response = $event->getResponse();
+        self::assertSame(Response::HTTP_TOO_MANY_REQUESTS, $response->getStatusCode());
+        $body = json_decode($response->getContent(), true);
+        // teapot disabled, so tooManyTitle is used; helper default is 'Too Many'
+        self::assertSame('Too Many', $body['message']);
+    }
+
+    /* ── invalid payload handling ─────────────────────────────────────── */
+
+    public function testInvalidHeaderPayloadStillRecordsFailureAndResponds(): void {
+        $loginManager = $this->createMock(LoginInterface::class);
+        // checkToken should not be called with a null payload
+        $loginManager->expects(self::never())->method('checkToken');
+
+        $listener = $this->makeListener(loginManager: $loginManager);
+
+        // an un-decodable header value
+        $request = Request::create('https://example.com/', 'GET');
+        $request->headers->set(self::HEADER_NAME, '!!!not-valid-base64!!!');
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        // Payload::decode returns null, so checkToken is skipped, but a
+        // failure response is still produced (the rate limiter is consulted)
+        self::assertTrue($event->hasResponse());
+        self::assertSame(Response::HTTP_UNAUTHORIZED, $event->getResponse()->getStatusCode());
+    }
+
+    public function testPostWithoutRequiredFieldsDoesNotAttemptLogin(): void {
+        $loginManager = $this->createMock(LoginInterface::class);
+        $loginManager->expects(self::never())->method('checkToken');
+
+        $domainManager = new DomainManager(true, 'auth.example.com');
+        $listener = $this->makeListener(
+            loginManager: $loginManager,
+            domainManager: $domainManager,
+        );
+
+        // POST to auth subdomain but missing the required fields
+        $request = Request::create('https://auth.example.com/', 'POST', ['username' => 'only-user']);
+
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        // Payload::load returns null (missing totp & nonce), so it falls through
+        // to the failure path and produces a response
+        self::assertTrue($event->hasResponse());
+    }
+}

tests/Unit/Listener/RejectListenerTest.php

@@ -0,0 +1,89 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Listener;
+
+use App\Listener\RejectListener;
+use App\Service\DomainManager;
+use App\Tests\Support\ListenerTestHelper;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\NullLogger;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+
+final class RejectListenerTest extends TestCase {
+    use ListenerTestHelper;
+
+    private function makeListener(
+        bool $teapot = true,
+        int $remainingTokens = 5,
+    ): RejectListener {
+        $listener = new RejectListener(
+            $this->makeConfig(teapot: $teapot),
+            $this->makeTwig(),
+            $this->makeRateLimiterFactory($remainingTokens),
+        );
+        $listener->setLogger(new NullLogger());
+        return $listener;
+    }
+
+    private function makeEvent(Request $request): RequestEvent {
+        return new RequestEvent(
+            $this->createStub(HttpKernelInterface::class),
+            $request,
+            HttpKernelInterface::MAIN_REQUEST,
+        );
+    }
+
+    public function testBlockedRequestReturnsTeapotWhenTeapotEnabled(): void {
+        $listener = $this->makeListener(teapot: true, remainingTokens: 0);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '1.2.3.4']);
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        self::assertSame(Response::HTTP_I_AM_A_TEAPOT, $response->getStatusCode());
+        self::assertSame('text/html', $response->headers->get('Content-Type'));
+    }
+
+    public function testBlockedRequestReturnsTooManyRequestsWhenTeapotDisabled(): void {
+        $listener = $this->makeListener(teapot: false, remainingTokens: 0);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '1.2.3.4']);
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        self::assertTrue($event->hasResponse());
+        $response = $event->getResponse();
+        self::assertSame(Response::HTTP_TOO_MANY_REQUESTS, $response->getStatusCode());
+        self::assertSame('text/html', $response->headers->get('Content-Type'));
+    }
+
+    public function testUnblockedRequestSetsNoResponse(): void {
+        $listener = $this->makeListener(remainingTokens: 5);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '1.2.3.4']);
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        // consume(0) with remaining tokens > 0 should not block
+        self::assertFalse($event->hasResponse());
+    }
+
+    public function testBlockedResponseContainsErrorTemplateContent(): void {
+        $listener = $this->makeListener(teapot: true, remainingTokens: 0);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '1.2.3.4']);
+        $event = $this->makeEvent($request);
+        $listener->onKernelRequest($event);
+
+        $content = $event->getResponse()->getContent();
+        // Twig escapes the apostrophe in "I'm a teapot" to &#039;
+        self::assertStringContainsString('a teapot', $content);
+        self::assertStringContainsString('I refuse to brew coffee', $content);
+    }
+}

tests/Unit/MonitorCacheKeysTest.php

@@ -0,0 +1,273 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit;
+
+use App\MonitorCacheKeys;
+use OutOfBoundsException;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+
+final class MonitorCacheKeysTest extends TestCase {
+    private function wrap(?ArrayAdapter $pool = null): MonitorCacheKeys {
+        $pool ??= new ArrayAdapter();
+        return new MonitorCacheKeys($pool);
+    }
+
+    public function testConstructorInitializesEmptyPool(): void {
+        $monitor = $this->wrap();
+
+        self::assertSame([], $monitor->getKeys());
+        self::assertSame([], $monitor->getChanges());
+    }
+
+    public function testSaveAddsKeyAndTracksChange(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('alpha');
+        $item->set('value');
+        $monitor->save($item);
+
+        self::assertSame(['alpha'], $monitor->getKeys());
+        self::assertSame(['alpha' => MonitorCacheKeys::UPDATED], $monitor->getChanges());
+    }
+
+    public function testSaveDeferredThenCommitAddsKey(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('beta');
+        $item->set('value');
+        $monitor->saveDeferred($item);
+
+        // saveDeferred calls update() which commits immediately
+        self::assertSame(['beta'], $monitor->getKeys());
+        self::assertSame(['beta' => MonitorCacheKeys::UPDATED], $monitor->getChanges());
+    }
+
+    public function testGetItemReturnsUnderlyingItem(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('mykey');
+        $item->set('data');
+        $monitor->save($item);
+
+        $fetched = $monitor->getItem('mykey');
+        self::assertTrue($fetched->isHit());
+        self::assertSame('data', $fetched->get());
+    }
+
+    public function testGetItemsReturnsMultipleItems(): void {
+        $monitor = $this->wrap();
+        $a = $monitor->getItem('a');
+        $a->set(1);
+        $monitor->save($a);
+        $b = $monitor->getItem('b');
+        $b->set(2);
+        $monitor->save($b);
+
+        $items = $monitor->getItems(['a', 'b']);
+        $keys = [];
+        foreach ($items as $key => $item) {
+            $keys[$key] = $item->get();
+        }
+        self::assertSame(['a' => 1, 'b' => 2], $keys);
+    }
+
+    public function testHasItemReturnsTrueForExistingKey(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('exists');
+        $item->set('v');
+        $monitor->save($item);
+
+        self::assertTrue($monitor->hasItem('exists'));
+        self::assertFalse($monitor->hasItem('missing'));
+    }
+
+    public function testDeleteItemRemovesKeyAndTracksRemoval(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('doomed');
+        $item->set('v');
+        $monitor->save($item);
+
+        $monitor->deleteItem('doomed');
+
+        self::assertSame([], $monitor->getKeys());
+        self::assertSame(['doomed' => MonitorCacheKeys::REMOVED], $monitor->getChanges());
+        self::assertFalse($monitor->hasItem('doomed'));
+    }
+
+    public function testDeleteItemOnMissingKeyIsNoop(): void {
+        $monitor = $this->wrap();
+
+        $result = $monitor->deleteItem('nonexistent');
+
+        self::assertTrue($result);
+        self::assertSame([], $monitor->getKeys());
+    }
+
+    public function testDeleteItemsRemovesMultipleKeys(): void {
+        $monitor = $this->wrap();
+        foreach (['x', 'y', 'z'] as $key) {
+            $item = $monitor->getItem($key);
+            $item->set($key);
+            $monitor->save($item);
+        }
+
+        $monitor->deleteItems(['x', 'y']);
+
+        self::assertSame(['z'], $monitor->getKeys());
+        $changes = $monitor->getChanges();
+        self::assertSame(MonitorCacheKeys::REMOVED, $changes['x']);
+        self::assertSame(MonitorCacheKeys::REMOVED, $changes['y']);
+    }
+
+    public function testDeleteItemsWithMissingKeysStillReturnsTrue(): void {
+        $monitor = $this->wrap();
+
+        $result = $monitor->deleteItems(['ghost1', 'ghost2']);
+
+        self::assertTrue($result);
+    }
+
+    public function testClearWipesPoolWhenNotEmpty(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('keep');
+        $item->set('v');
+        $monitor->save($item);
+
+        $result = $monitor->clear();
+
+        self::assertTrue($result);
+        self::assertSame([], $monitor->getKeys());
+    }
+
+    public function testClearIsNoopWhenEmpty(): void {
+        $monitor = $this->wrap();
+
+        $result = $monitor->clear();
+
+        self::assertTrue($result);
+    }
+
+    public function testMarkCleanResetsChangeList(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('temp');
+        $item->set('v');
+        $monitor->save($item);
+
+        self::assertNotEmpty($monitor->getChanges());
+
+        $monitor->markClean();
+
+        self::assertSame([], $monitor->getChanges());
+        self::assertSame(['temp'], $monitor->getKeys());
+    }
+
+    public function testCommitPassesThrough(): void {
+        $monitor = $this->wrap();
+
+        self::assertTrue($monitor->commit());
+    }
+
+    public function testSaveKeyListThrowsOutOfBoundsException(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('__key_list');
+
+        $this->expectException(OutOfBoundsException::class);
+        $monitor->save($item);
+    }
+
+    public function testSaveChangeListThrowsOutOfBoundsException(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('__chg_list');
+
+        $this->expectException(OutOfBoundsException::class);
+        $monitor->save($item);
+    }
+
+    public function testDeleteKeyListThrowsOutOfBoundsException(): void {
+        $monitor = $this->wrap();
+
+        $this->expectException(OutOfBoundsException::class);
+        $monitor->deleteItem('__key_list');
+    }
+
+    public function testDeleteChangeListThrowsOutOfBoundsException(): void {
+        $monitor = $this->wrap();
+
+        $this->expectException(OutOfBoundsException::class);
+        $monitor->deleteItem('__chg_list');
+    }
+
+    public function testDeleteItemsWithKeyListThrowsOutOfBoundsException(): void {
+        $monitor = $this->wrap();
+
+        $this->expectException(OutOfBoundsException::class);
+        $monitor->deleteItems(['safe', '__key_list']);
+    }
+
+    public function testDeleteItemsWithChangeListThrowsOutOfBoundsException(): void {
+        $monitor = $this->wrap();
+
+        $this->expectException(OutOfBoundsException::class);
+        $monitor->deleteItems(['__chg_list']);
+    }
+
+    public function testSaveDeferredOnKeyListThrowsOutOfBoundsException(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('safe');
+        $item->set('value');
+
+        // getItem returns the real item, but saveDeferred calls update() which
+        // validates the key — so we need to get the __key_list item and try to save it
+        $keyListItem = $monitor->getItem('__key_list');
+
+        $this->expectException(OutOfBoundsException::class);
+        $monitor->saveDeferred($keyListItem);
+    }
+
+    public function testSaveDeferredOnChangeListThrowsOutOfBoundsException(): void {
+        $monitor = $this->wrap();
+        $changeListItem = $monitor->getItem('__chg_list');
+
+        $this->expectException(OutOfBoundsException::class);
+        $monitor->saveDeferred($changeListItem);
+    }
+
+    public function testGetKeysReturnsEmptyArrayWhenKeyListMissing(): void {
+        // If the underlying pool loses its key list, getKeys should return []
+        $pool = new ArrayAdapter();
+        $monitor = new MonitorCacheKeys($pool);
+
+        $item = $monitor->getItem('alpha');
+        $item->set('value');
+        $monitor->save($item);
+
+        // delete the key list directly from the underlying pool
+        $pool->deleteItem('__key_list');
+
+        $monitor2 = new MonitorCacheKeys($pool);
+        // the constructor will re-initialize since __key_list is missing
+        // but getKeys on the new monitor should be empty
+        self::assertSame([], $monitor2->getKeys());
+    }
+
+    public function testDeleteItemReturnsTrueForExistingKey(): void {
+        $monitor = $this->wrap();
+        $item = $monitor->getItem('to-delete');
+        $item->set('value');
+        $monitor->save($item);
+
+        self::assertTrue($monitor->deleteItem('to-delete'));
+        self::assertNotContains('to-delete', $monitor->getKeys());
+    }
+
+    public function testDeleteItemsReturnsTrue(): void {
+        $monitor = $this->wrap();
+        foreach (['a', 'b', 'c'] as $key) {
+            $item = $monitor->getItem($key);
+            $item->set('value');
+            $monitor->save($item);
+        }
+
+        self::assertTrue($monitor->deleteItems(['a', 'b', 'c']));
+        self::assertSame([], $monitor->getKeys());
+    }
+}

tests/Unit/PersistCacheTest.php

@@ -0,0 +1,220 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit;
+
+use App\MonitorCacheKeys;
+use App\PersistCache;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+
+final class PersistCacheTest extends TestCase {
+    public function testBootWithEmptyStorageIsNoop(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+
+        // nothing was loaded since storage is empty
+        $monitor = new MonitorCacheKeys($sessionCache);
+        self::assertSame([], $monitor->getKeys());
+    }
+
+    public function testBootLoadsFromStorageIntoCache(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        // populate storage with some session data
+        $storageMonitor = new MonitorCacheKeys($sessionStorage);
+        $item = $storageMonitor->getItem('cookie_abc');
+        $item->set('user1');
+        $storageMonitor->save($item);
+        $storageMonitor->markClean();
+
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+
+        // session cache should now contain the loaded data
+        $cacheMonitor = new MonitorCacheKeys($sessionCache);
+        self::assertContains('cookie_abc', $cacheMonitor->getKeys());
+        self::assertSame('user1', $cacheMonitor->getItem('cookie_abc')->get());
+        // boot should mark clean so no changes are pending
+        self::assertSame([], $cacheMonitor->getChanges());
+    }
+
+    public function testBootDoesNotReloadWhenCacheAlreadyWarm(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        // warm up the cache with existing data
+        $cacheMonitor = new MonitorCacheKeys($sessionCache);
+        $item = $cacheMonitor->getItem('cookie_existing');
+        $item->set('old-user');
+        $cacheMonitor->save($item);
+
+        // put different data in storage
+        $storageMonitor = new MonitorCacheKeys($sessionStorage);
+        $item = $storageMonitor->getItem('cookie_new');
+        $item->set('new-user');
+        $storageMonitor->save($item);
+
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+
+        // existing data should be preserved, storage data NOT loaded
+        $monitor = new MonitorCacheKeys($sessionCache);
+        self::assertContains('cookie_existing', $monitor->getKeys());
+        self::assertNotContains('cookie_new', $monitor->getKeys());
+    }
+
+    public function testPersistWritesChangesToStorage(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+
+        // write something to the session cache
+        $cacheMonitor = new MonitorCacheKeys($sessionCache);
+        $item = $cacheMonitor->getItem('cookie_xyz');
+        $item->set('user2');
+        $cacheMonitor->save($item);
+
+        $persist->persist();
+
+        // storage should now contain the change
+        $storageMonitor = new MonitorCacheKeys($sessionStorage);
+        self::assertContains('cookie_xyz', $storageMonitor->getKeys());
+        self::assertSame('user2', $storageMonitor->getItem('cookie_xyz')->get());
+    }
+
+    public function testPersistHandlesRemovals(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        // seed storage with an item
+        $storageMonitor = new MonitorCacheKeys($sessionStorage);
+        $item = $storageMonitor->getItem('cookie_to_remove');
+        $item->set('user3');
+        $storageMonitor->save($item);
+        $storageMonitor->markClean();
+
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+
+        // now delete it from session cache
+        $cacheMonitor = new MonitorCacheKeys($sessionCache);
+        $cacheMonitor->deleteItem('cookie_to_remove');
+
+        $persist->persist();
+
+        // storage should no longer have it
+        $storageMonitor = new MonitorCacheKeys($sessionStorage);
+        self::assertNotContains('cookie_to_remove', $storageMonitor->getKeys());
+    }
+
+    public function testPersistIsNoopWhenNoChanges(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+        $persist->persist();
+
+        $storageMonitor = new MonitorCacheKeys($sessionStorage);
+        self::assertSame([], $storageMonitor->getKeys());
+    }
+
+    public function testFullBootModifyPersistCycle(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        // boot (empty), add data, persist
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+
+        $cacheMonitor = new MonitorCacheKeys($sessionCache);
+        $item = $cacheMonitor->getItem('cookie_cycle');
+        $item->set('cycled-user');
+        $cacheMonitor->save($item);
+
+        $persist->persist();
+
+        // simulate a new request: fresh cache, same storage
+        $newCache = new ArrayAdapter();
+        $persist2 = new PersistCache($newCache, $sessionStorage);
+        $persist2->boot();
+
+        $monitor = new MonitorCacheKeys($newCache);
+        self::assertContains('cookie_cycle', $monitor->getKeys());
+        self::assertSame('cycled-user', $monitor->getItem('cookie_cycle')->get());
+    }
+
+    public function testPersistHandlesMixedUpdatesAndRemovals(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        // seed storage with two items
+        $storageMonitor = new MonitorCacheKeys($sessionStorage);
+        $item1 = $storageMonitor->getItem('cookie_keep');
+        $item1->set('user-keep');
+        $storageMonitor->save($item1);
+        $item2 = $storageMonitor->getItem('cookie_remove');
+        $item2->set('user-remove');
+        $storageMonitor->save($item2);
+        $storageMonitor->markClean();
+
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+
+        // update one item and delete the other in the same cycle
+        $cacheMonitor = new MonitorCacheKeys($sessionCache);
+        $item1 = $cacheMonitor->getItem('cookie_keep');
+        $item1->set('user-updated');
+        $cacheMonitor->save($item1);
+        $cacheMonitor->deleteItem('cookie_remove');
+
+        $persist->persist();
+
+        // storage should reflect both changes
+        $storageMonitor = new MonitorCacheKeys($sessionStorage);
+        self::assertContains('cookie_keep', $storageMonitor->getKeys());
+        self::assertSame('user-updated', $storageMonitor->getItem('cookie_keep')->get());
+        self::assertNotContains('cookie_remove', $storageMonitor->getKeys());
+    }
+
+    public function testMultipleBootModifyPersistCycles(): void {
+        $sessionCache = new ArrayAdapter();
+        $sessionStorage = new ArrayAdapter();
+
+        // cycle 1: add item A
+        $persist = new PersistCache($sessionCache, $sessionStorage);
+        $persist->boot();
+        $cacheMonitor = new MonitorCacheKeys($sessionCache);
+        $item = $cacheMonitor->getItem('cookie_a');
+        $item->set('user-a');
+        $cacheMonitor->save($item);
+        $persist->persist();
+
+        // cycle 2: fresh cache, add item B, keep A from storage
+        $newCache = new ArrayAdapter();
+        $persist2 = new PersistCache($newCache, $sessionStorage);
+        $persist2->boot();
+        $cacheMonitor2 = new MonitorCacheKeys($newCache);
+        $item = $cacheMonitor2->getItem('cookie_b');
+        $item->set('user-b');
+        $cacheMonitor2->save($item);
+        $persist2->persist();
+
+        // cycle 3: fresh cache, both A and B should be loaded from storage
+        $newCache2 = new ArrayAdapter();
+        $persist3 = new PersistCache($newCache2, $sessionStorage);
+        $persist3->boot();
+        $monitor = new MonitorCacheKeys($newCache2);
+        self::assertContains('cookie_a', $monitor->getKeys());
+        self::assertSame('user-a', $monitor->getItem('cookie_a')->get());
+        self::assertContains('cookie_b', $monitor->getKeys());
+        self::assertSame('user-b', $monitor->getItem('cookie_b')->get());
+    }
+}

tests/Unit/Service/BackupCodeManagerTest.php

@@ -0,0 +1,215 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\BackupCodeManager;
+use App\Tests\Support\TotpTestHelper;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\NullLogger;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+
+final class BackupCodeManagerTest extends TestCase {
+    use TotpTestHelper;
+
+    private function makeManager(?ArrayAdapter $pool = null): BackupCodeManager {
+        $pool ??= new ArrayAdapter();
+        $manager = new BackupCodeManager($pool);
+        $manager->setConfig($this->makeConfig());
+        $manager->setLogger(new NullLogger());
+        return $manager;
+    }
+
+    public function testGenerateReturnsRequestedCount(): void {
+        $manager = $this->makeManager();
+
+        $codes = $manager->generate(5);
+
+        self::assertCount(5, $codes);
+        foreach ($codes as $code) {
+            self::assertIsString($code);
+            // codes are lowercase alphanumeric
+            self::assertMatchesRegularExpression('/^[a-z0-9]+$/', $code);
+        }
+    }
+
+    public function testGenerateDefaultCount(): void {
+        $manager = $this->makeManager();
+
+        $codes = $manager->generate();
+
+        self::assertCount(10, $codes);
+    }
+
+    public function testGenerateZeroReturnsEmptyArray(): void {
+        $manager = $this->makeManager();
+
+        $codes = $manager->generate(0);
+
+        self::assertSame([], $codes);
+    }
+
+    public function testGeneratedCodesAreStoredInCache(): void {
+        $pool = new ArrayAdapter();
+        $manager = $this->makeManager($pool);
+
+        $codes = $manager->generate(3);
+
+        // each code should be stored as a backup_ key
+        foreach ($codes as $code) {
+            $key = 'backup_' . strtolower($code);
+            // the manager uses makeCacheKey which sanitizes, but for alphanumeric it's identity
+            $item = $pool->getItem($key);
+            self::assertTrue($item->isHit(), "Expected cache hit for key: $key");
+            self::assertTrue($item->get(), "Expected code to be marked valid (true)");
+        }
+    }
+
+    public function testGeneratedCodesHaveFarFutureExpiry(): void {
+        $pool = new ArrayAdapter();
+        $manager = $this->makeManager($pool);
+
+        $codes = $manager->generate(1);
+        $code = $codes[0];
+
+        $item = $pool->getItem('backup_' . strtolower($code));
+        $expiry = $item->getMetadata()['expiry'];
+        self::assertGreaterThan((new \DateTimeImmutable('+10 years'))->getTimestamp(), (int) $expiry);
+    }
+
+    public function testVerifyAndConsumeValidCode(): void {
+        $manager = $this->makeManager();
+        $codes = $manager->generate(2);
+
+        $code = $codes[0];
+
+        self::assertTrue($manager->verifyAndConsume($code));
+    }
+
+    public function testVerifyAndConsumeMarksCodeAsUsed(): void {
+        $pool = new ArrayAdapter();
+        $manager = $this->makeManager($pool);
+        $codes = $manager->generate(1);
+        $code = $codes[0];
+
+        // first use succeeds
+        self::assertTrue($manager->verifyAndConsume($code));
+
+        // second use fails (already consumed)
+        self::assertFalse($manager->verifyAndConsume($code));
+    }
+
+    public function testVerifyAndConsumeInvalidCode(): void {
+        $manager = $this->makeManager();
+
+        self::assertFalse($manager->verifyAndConsume('nonexistent_code'));
+    }
+
+    public function testVerifyAndConsumeIsCaseInsensitive(): void {
+        $manager = $this->makeManager();
+        $codes = $manager->generate(1);
+        $code = $codes[0];
+
+        // uppercase version should still work
+        self::assertTrue($manager->verifyAndConsume(strtoupper($code)));
+    }
+
+    public function testVerifyAndConsumeStripsInvalidCharacters(): void {
+        $manager = $this->makeManager();
+        $codes = $manager->generate(1);
+        $code = $codes[0];
+
+        // inject spaces and special chars — should be stripped
+        self::assertTrue($manager->verifyAndConsume('  ' . $code . '!!'));
+    }
+
+    public function testExpireRemovesAllBackupCodes(): void {
+        $pool = new ArrayAdapter();
+        $manager = $this->makeManager($pool);
+        $codes = $manager->generate(5);
+
+        $manager->expire();
+
+        // all backup keys should be gone
+        foreach ($codes as $code) {
+            self::assertFalse($pool->hasItem('backup_' . strtolower($code)));
+        }
+    }
+
+    public function testExpireWhenNoBackupCodesIsNoop(): void {
+        $pool = new ArrayAdapter();
+        $manager = $this->makeManager($pool);
+
+        // should not throw
+        $manager->expire();
+
+        // this passes if no exception was thrown
+        self::assertTrue(true);
+    }
+
+    public function testExpireRemovesOnlyBackupPrefixedKeys(): void {
+        $pool = new ArrayAdapter();
+        $manager = $this->makeManager($pool);
+
+        $codes = $manager->generate(3);
+
+        // add a non-backup key
+        $item = $pool->getItem('cookie_session');
+        $item->set('data');
+        $pool->save($item);
+
+        $manager->expire();
+
+        // non-backup key survives
+        self::assertTrue($pool->hasItem('cookie_session'));
+
+        // backup keys are gone
+        foreach ($codes as $code) {
+            self::assertFalse($pool->hasItem('backup_' . strtolower($code)));
+        }
+    }
+
+    public function testVerifyAndConsumeEmptyStringReturnsFalse(): void {
+        $manager = $this->makeManager();
+
+        // empty string after preg_replace becomes 'backup_' with nothing after it
+        self::assertFalse($manager->verifyAndConsume(''));
+    }
+
+    public function testVerifyAndConsumeCodeWithValueFalseReturnsFalse(): void {
+        $pool = new ArrayAdapter();
+        $manager = $this->makeManager($pool);
+        $codes = $manager->generate(1);
+        $code = $codes[0];
+
+        // first use succeeds
+        self::assertTrue($manager->verifyAndConsume($code));
+
+        // the code is now marked as false (used); isHit is true but get() is false
+        $key = 'backup_' . strtolower($code);
+        $item = $pool->getItem($key);
+        self::assertTrue($item->isHit());
+        self::assertFalse($item->get());
+
+        // second use should fail because get() returns false
+        self::assertFalse($manager->verifyAndConsume($code));
+    }
+
+    public function testGenerateProducesUniqueCodes(): void {
+        $manager = $this->makeManager();
+
+        $codes = $manager->generate(50);
+
+        self::assertCount(50, $codes);
+        self::assertCount(50, array_unique($codes), 'All generated codes should be unique');
+    }
+
+    public function testGenerateCodeLengthIsDigitsPlusTwo(): void {
+        $manager = $this->makeManager();
+
+        $codes = $manager->generate(1);
+
+        // default TOTP digits is 6, so code length should be 6 + 2 = 8
+        self::assertSame(8, strlen($codes[0]));
+    }
+}

tests/Unit/Service/DomainManagerTest.php

@@ -0,0 +1,241 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\DomainManager;
+use PHPUnit\Framework\TestCase;
+
+final class DomainManagerTest extends TestCase {
+    private function createManager(bool $subdomainRedirect, string $authSubdomain): DomainManager {
+        return new DomainManager($subdomainRedirect, $authSubdomain);
+    }
+
+    /* ── authBase / getAuthSubdomain ─────────────────────────────────────── */
+
+    public function testAuthBaseIsNullWhenSubdomainRedirectIsDisabled(): void {
+        $manager = $this->createManager(false, 'auth.example.com');
+        self::assertNull($manager->authBase());
+        self::assertNull($manager->getAuthSubdomain());
+    }
+
+    public function testAuthBaseIsNullWhenAuthSubdomainIsEmpty(): void {
+        $manager = $this->createManager(true, '');
+        self::assertNull($manager->authBase());
+        self::assertNull($manager->getAuthSubdomain());
+    }
+
+    public function testAuthBaseExtractsSimpleDomain(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertSame('example.com', $manager->authBase());
+        self::assertSame('auth.example.com', $manager->getAuthSubdomain());
+    }
+
+    public function testAuthBaseExtractsMultiPartTld(): void {
+        $manager = $this->createManager(true, 'auth.example.co.uk');
+        self::assertSame('example.co.uk', $manager->authBase());
+        self::assertSame('auth.example.co.uk', $manager->getAuthSubdomain());
+    }
+
+    public function testAuthBaseIsNullForLocalhostAuth(): void {
+        $manager = $this->createManager(true, 'localhost');
+        self::assertNull($manager->authBase());
+        self::assertNull($manager->getAuthSubdomain());
+    }
+
+    public function testAuthBaseIsNullForIpAuth(): void {
+        $manager = $this->createManager(true, '192.168.1.1');
+        self::assertNull($manager->authBase());
+        self::assertNull($manager->getAuthSubdomain());
+    }
+
+    /* ── validReturn ──────────────────────────────────────────────────────── */
+
+    public function testValidReturnAcceptsAnyUrlWhenNoSubdomain(): void {
+        $manager = $this->createManager(false, '');
+        self::assertTrue($manager->validReturn('https://evil.com/page'));
+        self::assertTrue($manager->validReturn('https://example.com/ok'));
+    }
+
+    public function testValidReturnRejectsInvalidUrl(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertFalse($manager->validReturn('not-a-url'));
+        self::assertFalse($manager->validReturn(''));
+    }
+
+    public function testValidReturnAcceptsSameBaseDomain(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertTrue($manager->validReturn('https://app.example.com/dashboard'));
+        self::assertTrue($manager->validReturn('https://example.com/'));
+    }
+
+    public function testValidReturnRejectsDifferentBaseDomain(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertFalse($manager->validReturn('https://evil.com/phish'));
+        self::assertFalse($manager->validReturn('https://other-example.com/'));
+    }
+
+    public function testValidReturnHandlesCoUkTld(): void {
+        $manager = $this->createManager(true, 'auth.example.co.uk');
+        self::assertTrue($manager->validReturn('https://www.example.co.uk/'));
+        self::assertFalse($manager->validReturn('https://example.com/'));
+    }
+
+    public function testValidReturnRejectsUrlWithoutHost(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertFalse($manager->validReturn('mailto:test@example.com'));
+    }
+
+    /* ── matchesAuth ──────────────────────────────────────────────────────── */
+
+    public function testMatchesAuthIsFalseWhenSubdomainRedirectDisabled(): void {
+        $manager = $this->createManager(false, 'auth.example.com');
+        self::assertFalse($manager->matchesAuth('example.com'));
+        self::assertFalse($manager->matchesAuth('app.example.com'));
+    }
+
+    public function testMatchesAuthIsFalseWhenAuthSubdomainIsEmpty(): void {
+        $manager = $this->createManager(true, '');
+        self::assertFalse($manager->matchesAuth('example.com'));
+    }
+
+    public function testMatchesAuthMatchesSameBaseDomain(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertTrue($manager->matchesAuth('example.com'));
+        self::assertTrue($manager->matchesAuth('app.example.com'));
+    }
+
+    public function testMatchesAuthRejectsDifferentBaseDomain(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertFalse($manager->matchesAuth('evil.com'));
+        self::assertFalse($manager->matchesAuth('example.org'));
+    }
+
+    public function testMatchesAuthHandlesMultiPartTld(): void {
+        $manager = $this->createManager(true, 'auth.example.co.uk');
+        self::assertTrue($manager->matchesAuth('www.example.co.uk'));
+        self::assertFalse($manager->matchesAuth('example.com'));
+    }
+
+    public function testMatchesAuthRejectsIpHost(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertFalse($manager->matchesAuth('192.168.1.1'));
+    }
+
+    public function testMatchesAuthRejectsLocalhost(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertFalse($manager->matchesAuth('localhost'));
+    }
+
+    /* ── baseDomain edge cases via matchesAuth ────────────────────────────── */
+
+    public function testMatchesAuthWithDeepSubdomain(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertTrue($manager->matchesAuth('a.b.c.example.com'));
+    }
+
+    public function testMatchesAuthWithTwoPartDomain(): void {
+        /* for a 2-part auth subdomain, the baseDomain retains both parts */
+        $manager = $this->createManager(true, 'auth.local');
+        self::assertSame('auth.local', $manager->authBase());
+        self::assertTrue($manager->matchesAuth('auth.local'));
+        self::assertFalse($manager->matchesAuth('local'));
+        self::assertFalse($manager->matchesAuth('app.local'));
+    }
+
+    /* ── TLD table coverage ──────────────────────────────────────────────── */
+
+    public function testMatchesAuthWithComAuTld(): void {
+        // com.au is NOT in the TLD table (table has au? no, it doesn't),
+        // so it's treated as a standard 2-part TLD: base = com.au
+        $manager = $this->createManager(true, 'auth.example.com.au');
+        self::assertSame('com.au', $manager->authBase());
+        self::assertTrue($manager->matchesAuth('app.example.com.au'));
+        self::assertFalse($manager->matchesAuth('example.com'));
+    }
+
+    public function testMatchesAuthWithCoJpTld(): void {
+        // co.jp is NOT in the TLD table (table has jpn under com, not jp under co)
+        // so base = co.jp
+        $manager = $this->createManager(true, 'auth.example.co.jp');
+        self::assertSame('co.jp', $manager->authBase());
+        self::assertTrue($manager->matchesAuth('www.example.co.jp'));
+    }
+
+    public function testMatchesAuthWithComBrTld(): void {
+        // com.br: TLD table has com => [br], meaning *.br.com is multi-part
+        // but com.br has last=br, TLD['br'] doesn't exist, so base = com.br
+        $manager = $this->createManager(true, 'auth.example.com.br');
+        self::assertSame('com.br', $manager->authBase());
+        self::assertTrue($manager->matchesAuth('app.example.com.br'));
+    }
+
+    public function testMatchesAuthWithCoNzTld(): void {
+        // co.nz is NOT in the TLD table (nz => [co,net,org], so *.co.nz IS multi-part)
+        $manager = $this->createManager(true, 'auth.example.co.nz');
+        self::assertSame('example.co.nz', $manager->authBase());
+        self::assertTrue($manager->matchesAuth('sub.example.co.nz'));
+    }
+
+    public function testMatchesAuthWithComMxTld(): void {
+        // com.mx is NOT in the TLD table (mx => [com,net,org], so *.com.mx IS multi-part)
+        $manager = $this->createManager(true, 'auth.example.com.mx');
+        self::assertSame('example.com.mx', $manager->authBase());
+        self::assertTrue($manager->matchesAuth('app.example.com.mx'));
+    }
+
+    public function testMatchesAuthWithCoInTld(): void {
+        // co.in: in => [co,...], so *.co.in IS multi-part
+        $manager = $this->createManager(true, 'auth.example.co.in');
+        self::assertSame('example.co.in', $manager->authBase());
+        self::assertTrue($manager->matchesAuth('app.example.co.in'));
+    }
+
+    public function testMatchesAuthWithBrComTld(): void {
+        // br.com: TLD table has com => [br], so *.br.com IS multi-part
+        $manager = $this->createManager(true, 'auth.example.br.com');
+        self::assertSame('example.br.com', $manager->authBase());
+        self::assertTrue($manager->matchesAuth('app.example.br.com'));
+    }
+
+    public function testSimpleTldNotTreatedAsMultiPart(): void {
+        // example.com is a standard 2-part domain, not multi-part
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertSame('example.com', $manager->authBase());
+        // auth.example.org should NOT match example.com
+        self::assertFalse($manager->matchesAuth('app.example.org'));
+    }
+
+    /* ── baseDomain edge cases ───────────────────────────────────────────── */
+
+    public function testMatchesAuthWithSingleLabelHost(): void {
+        // a single-label domain (not localhost, not IP) has baseLength 1
+        // so 'myhost' has baseDomain 'myhost', while 'auth.local' has base 'auth.local'
+        // they won't match unless the auth subdomain itself is single-label
+        $manager = $this->createManager(true, 'auth.local');
+        // auth.local base is 'auth.local', 'local' base is 'local' -> no match
+        self::assertFalse($manager->matchesAuth('local'));
+        // but a subdomain of auth.local does match
+        self::assertTrue($manager->matchesAuth('app.auth.local'));
+    }
+
+    public function testMatchesAuthWithEmptyStringHost(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertFalse($manager->matchesAuth(''));
+    }
+
+    public function testValidReturnAcceptsUrlWithPort(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertTrue($manager->validReturn('https://example.com:8080/path'));
+    }
+
+    public function testValidReturnAcceptsUrlWithoutPath(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertTrue($manager->validReturn('https://example.com'));
+    }
+
+    public function testValidReturnRejectsDifferentDomainWithPort(): void {
+        $manager = $this->createManager(true, 'auth.example.com');
+        self::assertFalse($manager->validReturn('https://evil.com:8080/path'));
+    }
+}

tests/Unit/Service/LoginManagerTest.php

@@ -0,0 +1,424 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Data\Payload;
+use App\Enum\Scope;
+use App\Service\BackupCodeInterface;
+use App\Service\DomainManager;
+use App\Trait\StringTrait;
+use App\Service\LoginManager;
+use App\Tests\Support\TotpTestHelper;
+use PHPUnit\Framework\TestCase;
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Log\NullLogger;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Exception\HttpException;
+
+final class LoginManagerTest extends TestCase {
+    use TotpTestHelper;
+    use StringTrait;
+
+    private ArrayAdapter $pool;
+    private BackupCodeInterface $backupCodeManager;
+    private DomainManager $domainManager;
+
+    private function makeLoginManager(
+        ?int $ipTtl = 0,
+        bool $subdomainRedirect = false,
+        string $authSubdomain = '',
+    ): LoginManager {
+        $this->pool = new ArrayAdapter();
+        $this->backupCodeManager = $this->createStub(BackupCodeInterface::class);
+        $this->domainManager = new DomainManager($subdomainRedirect, $authSubdomain);
+
+        $manager = new LoginManager($this->pool, $this->backupCodeManager, $this->domainManager);
+        $manager->setConfig($this->makeConfig(ipTtl: $ipTtl));
+        $manager->setLogger(new NullLogger());
+        $manager->setNonceCache(new ArrayAdapter());
+        return $manager;
+    }
+
+    /** Build a Payload with a valid server-side nonce already stored. */
+    private function makePayloadWithNonce(
+        LoginManager $manager,
+        string $id = 'testuser',
+        Scope $scope = Scope::Cookie,
+        ?string $token = null,
+    ): Payload {
+        $token ??= $this->validTotpCode();
+        $nonce = $this->insertNonce($manager, 'test-nonce-123');
+
+        $payload = new Payload();
+        $payload->id = $id;
+        $payload->token = $token;
+        $payload->nonce = $nonce;
+        $payload->json = true;
+        $payload->scope = $scope;
+        return $payload;
+    }
+
+    /** Inject a nonce directly into the manager's nonce cache. */
+    private function insertNonce(LoginManager $manager, string $nonce): string {
+        $reflection = new \ReflectionProperty(LoginManager::class, 'nonceCache');
+        $nonceCache = $reflection->getValue($manager);
+
+        $key = $this->makeCacheKey($nonce);
+        $item = $nonceCache->getItem($key);
+        $item->set(true);
+        $nonceCache->save($item);
+
+        return $nonce;
+    }
+
+    public function testCheckTokenReturnsNullForInvalidTotp(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, token: 'wrong-code');
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/', 'GET');
+
+        self::assertNull($manager->checkToken($payload, $request));
+    }
+
+    public function testCheckTokenReturnsNullForSpentNonce(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        // spend the nonce first (use the same cache key the manager does)
+        $reflection = new \ReflectionProperty(LoginManager::class, 'nonceCache');
+        $nonceCache = $reflection->getValue($manager);
+        $nonceItem = $nonceCache->getItem($this->makeCacheKey('test-nonce-123'));
+        $nonceItem->set(false);
+        $nonceCache->save($nonceItem);
+
+        $request = Request::create('/', 'GET');
+
+        self::assertNull($manager->checkToken($payload, $request));
+    }
+
+    public function testCheckTokenReturnsNullForMissingNonce(): void {
+        $manager = $this->makeLoginManager();
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $payload = new Payload();
+        $payload->id = 'user1';
+        $payload->token = $this->validTotpCode();
+        $payload->nonce = 'never-stored';
+        $payload->json = true;
+        $payload->scope = Scope::Cookie;
+
+        $request = Request::create('/', 'GET');
+
+        self::assertNull($manager->checkToken($payload, $request));
+    }
+
+    public function testSuccessfulTotpLoginWithCookieScopeReturnsRedirect(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::Cookie);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/dashboard', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        self::assertSame(303, $response->getStatusCode()); // HTTP_SEE_OTHER
+        self::assertTrue($response->headers->has('Location'));
+        self::assertTrue($response->headers->has('Set-Cookie'));
+    }
+
+    public function testSuccessfulLoginWithNoneScopeReturnsPlainResponse(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::None);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        self::assertSame(200, $response->getStatusCode());
+        self::assertSame('text/plain', $response->headers->get('Content-Type'));
+        self::assertTrue($response->headers->has('Remote-User'));
+        // no redirect for Scope::None
+        self::assertFalse($response->headers->has('Location'));
+    }
+
+    public function testSuccessfulLoginSetsRemoteUserHeader(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, id: 'alice', scope: Scope::None);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        self::assertSame('alice', $response->headers->get('Remote-User'));
+    }
+
+    public function testSuccessfulLoginJsonResponse(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::Cookie, token: null);
+        $payload->json = true;
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/protected', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        self::assertSame('application/json', $response->headers->get('Content-Type'));
+        $body = json_decode($response->getContent(), true);
+        self::assertSame('Login successful', $body['message']);
+    }
+
+    public function testSuccessfulLoginHtmlResponse(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::Cookie);
+        $payload->json = false;
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/protected', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        self::assertSame('text/html', $response->headers->get('Content-Type'));
+    }
+
+    public function testSuccessfulLoginWithReturnUrl(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::Cookie);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/login?return=https://example.com/app', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        self::assertSame('https://example.com/app', $response->headers->get('Location'));
+    }
+
+    public function testSuccessfulLoginWithInvalidReturnFallsBackToPath(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::Cookie);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/login?return=not-a-url', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        $location = $response->headers->get('Location');
+        self::assertStringStartsWith('/login', $location);
+    }
+
+    public function testIpScopeDowngradesToCookieWhenIpAccessDisabled(): void {
+        $manager = $this->makeLoginManager(ipTtl: 0);
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::Ip);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        // Should have a Set-Cookie (downgraded to cookie scope)
+        self::assertNotNull($response);
+        self::assertTrue($response->headers->has('Set-Cookie'));
+    }
+
+    public function testIpScopeWhenEnabledSetsIpSession(): void {
+        $manager = $this->makeLoginManager(ipTtl: 1800);
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::Ip);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/', 'GET', [], [], [], ['REMOTE_ADDR' => '1.2.3.4']);
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        // IP session should be stored; no Set-Cookie for IP scope
+        self::assertFalse($response->headers->has('Set-Cookie'));
+
+        // verify the IP session exists in the cache
+        $reflection = new \ReflectionProperty(LoginManager::class, 'sessionCache');
+        $sessionCache = $reflection->getValue($manager);
+        self::assertTrue($sessionCache->hasItem('ip_1.2.3.4'));
+    }
+
+    public function testBackupCodeAuthentication(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, token: 'backup-code-123');
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(true);
+
+        $request = Request::create('/', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        self::assertSame(303, $response->getStatusCode());
+    }
+
+    public function testNonceIsConsumedAfterSuccessfulLogin(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $request = Request::create('/', 'GET');
+
+        $manager->checkToken($payload, $request);
+
+        // nonce should now be marked invalid (false); look it up via the same
+        // cache key the manager uses (makeCacheKey rewrites '-' to '_')
+        $reflection = new \ReflectionProperty(LoginManager::class, 'nonceCache');
+        $nonceCache = $reflection->getValue($manager);
+        $nonceItem = $nonceCache->getItem($this->makeCacheKey('test-nonce-123'));
+        self::assertFalse($nonceItem->get());
+    }
+
+    public function testUlidCollisionThrowsHttpException(): void {
+        // Use a stub pool where every cookie_ key is already a hit (collision)
+        $pool = $this->createStub(CacheItemPoolInterface::class);
+        $item = $this->createStub(CacheItemInterface::class);
+        $item->method('isHit')->willReturn(true);
+        $item->method('get')->willReturn('existing');
+        // The nonce cache needs to work, so we return the stub item for
+        // cookie_ keys but a real working item for nonce keys.
+        $pool->method('getItem')->willReturnCallback(function (string $key) use ($item) {
+            if (str_starts_with($key, 'cookie_')) {
+                return $item; // collision
+            }
+            // For nonce keys, return a real item from an ArrayAdapter
+            static $realPool = null;
+            $realPool ??= new \Symfony\Component\Cache\Adapter\ArrayAdapter();
+            return $realPool->getItem($key);
+        });
+        $pool->method('hasItem')->willReturnCallback(function (string $key) use ($item) {
+            if (str_starts_with($key, 'cookie_')) {
+                return true;
+            }
+            static $realPool = null;
+            $realPool ??= new \Symfony\Component\Cache\Adapter\ArrayAdapter();
+            return $realPool->hasItem($key);
+        });
+        $pool->method('save')->willReturn(true);
+        $pool->method('saveDeferred')->willReturn(true);
+        $pool->method('commit')->willReturn(true);
+        $pool->method('getItems')->willReturnCallback(function (array $keys) {
+            static $realPool = null;
+            $realPool ??= new \Symfony\Component\Cache\Adapter\ArrayAdapter();
+            return $realPool->getItems($keys);
+        });
+        $pool->method('clear')->willReturn(true);
+        $pool->method('deleteItem')->willReturn(true);
+        $pool->method('deleteItems')->willReturn(true);
+
+        $this->domainManager = new DomainManager(false, '');
+        $this->backupCodeManager = $this->createStub(BackupCodeInterface::class);
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        $manager = new LoginManager($pool, $this->backupCodeManager, $this->domainManager);
+        $manager->setConfig($this->makeConfig());
+        $manager->setLogger(new NullLogger());
+        $manager->setNonceCache(new \Symfony\Component\Cache\Adapter\ArrayAdapter());
+
+        $payload = new Payload();
+        $payload->id = 'collide-user';
+        $payload->token = $this->validTotpCode();
+        $payload->nonce = 'test-nonce-123';
+        $payload->json = true;
+        $payload->scope = Scope::Cookie;
+
+        // inject the nonce
+        $this->insertNonce($manager, 'test-nonce-123');
+
+        $request = Request::create('/', 'GET');
+
+        $this->expectException(HttpException::class);
+        $manager->checkToken($payload, $request);
+    }
+
+    public function testCookieScopeWithCentralAuthSetsDomainOnMatchingHost(): void {
+        $manager = $this->makeLoginManager(
+            subdomainRedirect: true,
+            authSubdomain: 'auth.example.com',
+        );
+        $payload = $this->makePayloadWithNonce($manager, id: 'alice', scope: Scope::Cookie);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        // host matches the auth base domain
+        $request = Request::create('https://auth.example.com/', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        $cookies = $response->headers->getCookies();
+        self::assertCount(1, $cookies);
+        // when using central auth and host matches, the cookie domain is set
+        self::assertSame('example.com', $cookies[0]->getDomain());
+        // the auth cookie name is used instead of the host-prefixed name
+        self::assertSame('__Http-Domain-Preauth', $cookies[0]->getName());
+    }
+
+    public function testCookieScopeWithCentralAuthOnNonMatchingHostUsesNullDomain(): void {
+        $manager = $this->makeLoginManager(
+            subdomainRedirect: true,
+            authSubdomain: 'auth.example.com',
+        );
+        $payload = $this->makePayloadWithNonce($manager, id: 'bob', scope: Scope::Cookie);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        // host does NOT match the auth base domain
+        $request = Request::create('https://other.com/', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        $cookies = $response->headers->getCookies();
+        self::assertCount(1, $cookies);
+        // domain is null when host does not match
+        self::assertNull($cookies[0]->getDomain());
+        // still uses auth cookie name since authBase is set
+        self::assertSame('__Http-Domain-Preauth', $cookies[0]->getName());
+    }
+
+    public function testCheckTokenWithEmptyReturnParameterFallsBackToPath(): void {
+        $manager = $this->makeLoginManager();
+        $payload = $this->makePayloadWithNonce($manager, scope: Scope::Cookie);
+
+        $this->backupCodeManager->method('verifyAndConsume')->willReturn(false);
+
+        // return parameter is present but empty string
+        $request = Request::create('/?return=', 'GET');
+
+        $response = $manager->checkToken($payload, $request);
+
+        self::assertNotNull($response);
+        $location = $response->headers->get('Location');
+        self::assertNotNull($location);
+        // should fall back to path since empty string is not a valid URL
+        self::assertStringStartsWith('/', $location);
+    }
+}

tests/Unit/Trait/CookieNameTraitTest.php

@@ -0,0 +1,23 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Trait;
+
+use App\Trait\CookieNameTrait;
+use PHPUnit\Framework\TestCase;
+
+final class CookieNameTraitTest extends TestCase {
+    use CookieNameTrait;
+
+    public function testCookieName(): void {
+        self::assertSame('__Host-Http-Preauth', $this->cookieName());
+    }
+
+    public function testAuthCookieName(): void {
+        self::assertSame('__Http-Domain-Preauth', $this->authCookieName());
+    }
+
+    public function testHeaderName(): void {
+        self::assertSame('X-Preauth', $this->headerName());
+    }
+}

tests/Unit/Trait/GetTotpTraitTest.php

@@ -0,0 +1,90 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Trait;
+
+use App\ConfigBag;
+use App\Tests\Support\TotpTestHelper;
+use App\Trait\GetTotpTrait;
+use OTPHP\TOTPInterface;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpKernel\Exception\HttpException;
+
+final class GetTotpTraitTest extends TestCase {
+    use TotpTestHelper;
+
+    private function makeObject(): object {
+        return new class {
+            use GetTotpTrait;
+
+            public function publicGetTotp(): TOTPInterface {
+                return $this->getTotp();
+            }
+        };
+    }
+
+    public function testSetConfigSetsProperty(): void {
+        $obj = $this->makeObject();
+        $config = $this->makeConfig();
+
+        $obj->setConfig($config);
+
+        $reflection = new \ReflectionProperty($obj, 'config');
+        self::assertSame($config, $reflection->getValue($obj));
+    }
+
+    public function testGetTotpReturnsTotpInterface(): void {
+        $obj = $this->makeObject();
+        $obj->setConfig($this->makeConfig());
+
+        $totp = $obj->publicGetTotp();
+
+        self::assertInstanceOf(TOTPInterface::class, $totp);
+    }
+
+    public function testGetTotpReturnsValidCode(): void {
+        $obj = $this->makeObject();
+        $obj->setConfig($this->makeConfig());
+
+        $totp = $obj->publicGetTotp();
+
+        // the code at the frozen time should match our helper
+        self::assertSame($this->validTotpCode(), $totp->now());
+    }
+
+    public function testGetTotpThrowsOnInvalidUri(): void {
+        $obj = $this->makeObject();
+        $clock = $this->frozenClock();
+        $utilities = $this->createUtilities($clock);
+        $config = new ConfigBag(
+            $utilities, $clock,
+            3600, 'not-a-valid-uri', 0, false,
+            'Error', 'Teapot', 'Too Many'
+        );
+        $obj->setConfig($config);
+
+        // Factory::loadFromProvisioningUri throws InvalidProvisioningUriException
+        // which is not caught by getTotp() since the instanceof check only runs
+        // after a successful load — so we expect a Throwable here
+        $this->expectException(\Throwable::class);
+        $obj->publicGetTotp();
+    }
+
+    public function testGetTotpThrowsHttpExceptionWhenNotTotpType(): void {
+        // A HOTP URI loads successfully as an OTPInterface but is NOT a TOTPInterface,
+        // so the instanceof check in getTotp() should throw an HttpException(500)
+        $obj = $this->makeObject();
+        $clock = $this->frozenClock();
+        $utilities = $this->createUtilities($clock);
+        $config = new ConfigBag(
+            $utilities, $clock,
+            3600, 'otpauth://hotp/Test-HOTP?secret=JBSWY3DPEHPK3PXP&counter=0', 0, false,
+            'Error', 'Teapot', 'Too Many'
+        );
+        $obj->setConfig($config);
+
+        $this->expectException(HttpException::class);
+        $this->expectExceptionMessage('Internal Server Exception');
+        $obj->publicGetTotp();
+    }
+}

tests/Unit/Trait/HasLoggerTraitTest.php

@@ -0,0 +1,18 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Trait;
+
+use App\Trait\HasLoggerTrait;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+
+final class HasLoggerTraitTest extends TestCase {
+    use HasLoggerTrait;
+
+    public function testSetLogger(): void {
+        $logger = $this->createStub(LoggerInterface::class);
+        $this->setLogger($logger);
+        self::assertSame($logger, $this->logger);
+    }
+}

tests/Unit/Trait/MakeNonceTraitTest.php

@@ -0,0 +1,176 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Trait;
+
+use App\Trait\MakeNonceTrait;
+use PHPUnit\Framework\TestCase;
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Log\NullLogger;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\HttpKernel\Exception\HttpException;
+
+/**
+ * Wraps the trait in a concrete class with public proxies so the protected
+ * methods can be exercised from test scope.
+ */
+final class MakeNonceTraitTest extends TestCase {
+    private function makeObject(): object {
+        return new class {
+            use MakeNonceTrait;
+
+            public function publicMakeNonce(int $retries = 3): string {
+                return $this->makeNonce($retries);
+            }
+
+            public function publicMakeCacheKey(string $name): string {
+                return $this->makeCacheKey($name);
+            }
+        };
+    }
+
+    public function testMakeNonceReturnsBase64UrlString(): void {
+        $obj = $this->makeObject();
+        $obj->setLogger(new NullLogger());
+        $obj->setNonceCache(new ArrayAdapter());
+
+        $nonce = $obj->publicMakeNonce();
+
+        self::assertIsString($nonce);
+        // 15 bytes -> 20 base64 chars without padding
+        self::assertSame(20, strlen($nonce));
+        // base64url charset only
+        self::assertMatchesRegularExpression('/^[A-Za-z0-9_-]+$/', $nonce);
+    }
+
+    public function testMakeNonceStoresNonceInCache(): void {
+        $pool = new ArrayAdapter();
+        $obj = $this->makeObject();
+        $obj->setLogger(new NullLogger());
+        $obj->setNonceCache($pool);
+
+        $nonce = $obj->publicMakeNonce();
+
+        // makeNonce stores via makeCacheKey() which rewrites '-' to '_'
+        $key = $obj->publicMakeCacheKey($nonce);
+        self::assertTrue($pool->hasItem($key));
+        $item = $pool->getItem($key);
+        self::assertTrue($item->get());
+    }
+
+    public function testMakeNonceSetsExpiry(): void {
+        $pool = new ArrayAdapter();
+        $obj = $this->makeObject();
+        $obj->setLogger(new NullLogger());
+        $obj->setNonceCache($pool);
+
+        $nonce = $obj->publicMakeNonce();
+
+        $item = $pool->getItem($obj->publicMakeCacheKey($nonce));
+        $expiry = $item->getMetadata()['expiry'];
+        // NONCE_TTL is 120 seconds
+        self::assertLessThanOrEqual(120, (int) $expiry - time());
+        self::assertGreaterThan(time(), (int) $expiry);
+    }
+
+    public function testTwoNoncesAreDifferent(): void {
+        $pool = new ArrayAdapter();
+        $obj = $this->makeObject();
+        $obj->setLogger(new NullLogger());
+        $obj->setNonceCache($pool);
+
+        $nonce1 = $obj->publicMakeNonce();
+        $nonce2 = $obj->publicMakeNonce();
+
+        self::assertNotSame($nonce1, $nonce2);
+    }
+
+    public function testMakeNonceThrowsAfterMaxRetries(): void {
+        // Create a stub pool that always reports every key as a hit (collision)
+        $pool = $this->createStub(CacheItemPoolInterface::class);
+        $item = $this->createStub(CacheItemInterface::class);
+        $item->method('isHit')->willReturn(true);
+        $item->method('get')->willReturn(true);
+        $pool->method('getItem')->willReturn($item);
+        $pool->method('save')->willReturn(true);
+
+        $obj = $this->makeObject();
+        $obj->setLogger(new NullLogger());
+        $obj->setNonceCache($pool);
+
+        $this->expectException(HttpException::class);
+        $this->expectExceptionMessage('Internal Server Error');
+
+        $obj->publicMakeNonce();
+    }
+
+    public function testMakeNonceRetriesAndSucceedsAfterCollision(): void {
+        // Use a spy pool that returns isHit=true on the first getItem call
+        // (simulating a collision), then delegates to a real ArrayAdapter for
+        // subsequent calls so the retry succeeds.
+        $realPool = new ArrayAdapter();
+        $collisionCount = 0;
+
+        $spyPool = new class($realPool, $collisionCount) implements CacheItemPoolInterface {
+            private int $hits = 0;
+            public function __construct(
+                private CacheItemPoolInterface $inner,
+                private int &$hitCounter,
+            ) {}
+
+            public function getItem(string $key): CacheItemInterface {
+                $item = $this->inner->getItem($key);
+                // pretend the first requested key is already a hit (collision)
+                if ($this->hits === 0) {
+                    $this->hits++;
+                    $this->hitCounter++;
+                    return new class($key) implements CacheItemInterface {
+                        public function __construct(private string $key) {}
+                        public function getKey(): string { return $this->key; }
+                        public function get(): mixed { return true; }
+                        public function isHit(): bool { return true; }
+                        public function set(mixed $value): static { return $this; }
+                        public function expiresAt(?\DateTimeInterface $expiration): static { return $this; }
+                        public function expiresAfter(int|\DateInterval|null $time): static { return $this; }
+                    };
+                }
+                return $item;
+            }
+            public function getItems(array $keys = []): iterable { return $this->inner->getItems($keys); }
+            public function hasItem(string $key): bool { return $this->inner->hasItem($key); }
+            public function clear(): bool { return $this->inner->clear(); }
+            public function deleteItem(string $key): bool { return $this->inner->deleteItem($key); }
+            public function deleteItems(array $keys): bool { return $this->inner->deleteItems($keys); }
+            public function save(CacheItemInterface $item): bool { return $this->inner->save($item); }
+            public function saveDeferred(CacheItemInterface $item): bool { return $this->inner->saveDeferred($item); }
+            public function commit(): bool { return $this->inner->commit(); }
+        };
+
+        $obj = $this->makeObject();
+        $obj->setLogger(new NullLogger());
+        $obj->setNonceCache($spyPool);
+
+        // should retry and succeed on the second attempt
+        $nonce = $obj->publicMakeNonce();
+        self::assertIsString($nonce);
+        self::assertSame(20, strlen($nonce));
+        self::assertSame(1, $collisionCount, 'Expected exactly one collision before success');
+    }
+
+    public function testMakeNonceThrowsImmediatelyWithZeroRetries(): void {
+        $pool = $this->createStub(CacheItemPoolInterface::class);
+        $item = $this->createStub(CacheItemInterface::class);
+        $item->method('isHit')->willReturn(true);
+        $item->method('get')->willReturn(true);
+        $pool->method('getItem')->willReturn($item);
+        $pool->method('save')->willReturn(true);
+
+        $obj = $this->makeObject();
+        $obj->setLogger(new NullLogger());
+        $obj->setNonceCache($pool);
+
+        $this->expectException(HttpException::class);
+        $obj->publicMakeNonce(0);
+    }
+}

tests/Unit/Trait/StringTraitTest.php

@@ -0,0 +1,60 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Trait;
+
+use App\Trait\StringTrait;
+use PHPUnit\Framework\TestCase;
+
+final class StringTraitTest extends TestCase {
+    use StringTrait;
+
+    public function testMakeCacheKeySanitizesInvalidChars(): void {
+        self::assertSame('hello_world', $this->makeCacheKey('hello world'));
+        self::assertSame('hello_world', $this->makeCacheKey('hello!world'));
+        self::assertSame('a_b_c_d', $this->makeCacheKey('a/b@c#d'));
+    }
+
+    public function testMakeCacheKeyPreservesValidChars(): void {
+        self::assertSame('ABC_123.abc', $this->makeCacheKey('ABC_123.abc'));
+    }
+
+    public function testMakeCacheKeyTruncatesLongNames(): void {
+        $long = str_repeat('a', 300);
+        $result = $this->makeCacheKey($long);
+        self::assertSame(128, mb_strlen($result));
+    }
+
+    public function testMakeCacheKeyEmptyString(): void {
+        self::assertSame('', $this->makeCacheKey(''));
+    }
+
+    public function testMakeCacheKeyWithOnlyInvalidChars(): void {
+        // preg_replace with + collapses consecutive invalid chars into one _
+        self::assertSame('_', $this->makeCacheKey('!!!'));
+        self::assertSame('_', $this->makeCacheKey('   '));
+        self::assertSame('_', $this->makeCacheKey('!@#'));
+        self::assertSame('_', $this->makeCacheKey('!@ #'));
+    }
+
+    public function testMakeCacheKeyTruncatesToExactly128(): void {
+        $input = str_repeat('a', 128);
+        self::assertSame(128, mb_strlen($this->makeCacheKey($input)));
+        self::assertSame($input, $this->makeCacheKey($input));
+
+        $input129 = str_repeat('a', 129);
+        self::assertSame(128, mb_strlen($this->makeCacheKey($input129)));
+    }
+
+    public function testMakeCacheKeyWithMultibyteChars(): void {
+        // multibyte chars are replaced with a single underscore
+        $result = $this->makeCacheKey('héllo wörld');
+        // é and ö are not in [A-Za-z0-9_.] so they become _
+        self::assertSame('h_llo_w_rld', $result);
+    }
+
+    public function testMakeCacheKeyWithEmoji(): void {
+        $result = $this->makeCacheKey('a🎉b');
+        self::assertSame('a_b', $result);
+    }
+}

tests/Unit/UtilitiesTest.php

@@ -0,0 +1,69 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Tests\Unit;
+
+use App\Utilities;
+use PHPUnit\Framework\TestCase;
+use Psr\Clock\ClockInterface;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+
+final class UtilitiesTest extends TestCase {
+    private function makeUtilities(?ArrayAdapter $pool = null, ?ClockInterface $clock = null): Utilities {
+        $pool ??= new ArrayAdapter();
+        $clock ??= $this->createStub(ClockInterface::class);
+        return new Utilities($clock, $pool);
+    }
+
+    public function testLoadTotpReturnsCachedValueWhenPresent(): void {
+        $pool = new ArrayAdapter();
+        $item = $pool->getItem('totp');
+        $item->set('otpauth://totp/cached?secret=ABCDEFGH');
+        $pool->save($item);
+
+        $utilities = $this->makeUtilities($pool);
+
+        $result = $utilities->loadTotp();
+
+        self::assertSame('otpauth://totp/cached?secret=ABCDEFGH', $result);
+    }
+
+    public function testLoadTotpGeneratesAndStoresWhenMissing(): void {
+        $pool = new ArrayAdapter();
+        $utilities = $this->makeUtilities($pool);
+
+        $result = $utilities->loadTotp();
+
+        self::assertNotEmpty($result);
+        self::assertStringStartsWith('otpauth://totp/', $result);
+
+        // stored in cache for next boot
+        $cached = $pool->getItem('totp');
+        self::assertTrue($cached->isHit());
+        self::assertSame($result, $cached->get());
+    }
+
+    public function testLoadTotpSetsFarFutureExpiry(): void {
+        $pool = new ArrayAdapter();
+        $utilities = $this->makeUtilities($pool);
+
+        $utilities->loadTotp();
+
+        $cached = $pool->getItem('totp');
+        $expiry = $cached->getMetadata()['expiry'];
+        // 2999-12-31 is well in the future, far beyond any reasonable test timestamp
+        self::assertGreaterThan((new \DateTimeImmutable('+10 years'))->getTimestamp(), (int) $expiry);
+    }
+
+    public function testLoadTotpIsIdempotentAfterGeneration(): void {
+        $pool = new ArrayAdapter();
+        $utilities = $this->makeUtilities($pool);
+
+        $first = $utilities->loadTotp();
+
+        // second call should find it in cache and return the same value
+        $second = $utilities->loadTotp();
+
+        self::assertSame($first, $second);
+    }
+}

tests/bootstrap.php

@@ -0,0 +1,13 @@
+<?php
+
+use Symfony\Component\Dotenv\Dotenv;
+
+require dirname(__DIR__).'/vendor/autoload.php';
+
+if (method_exists(Dotenv::class, 'bootEnv')) {
+    (new Dotenv())->bootEnv(dirname(__DIR__).'/.env.test');
+}
+
+if (!isset($_SERVER['APP_DEBUG'])) {
+    $_SERVER['APP_DEBUG'] = false;
+}