refactor: get rid of package expressions by moving the code into package expression

Signed-off-by: Xe Iaso <me@xeiaso.net>

.devcontainer/devcontainer.json

@@ -2,10 +2,12 @@
 // README at: https://github.com/devcontainers/templates/tree/main/src/debian
 {
   "name": "Dev",
-  "dockerComposeFile": ["./docker-compose.yaml"],
+  "dockerComposeFile": [
+    "./docker-compose.yaml"
+  ],
   "service": "workspace",
   "workspaceFolder": "/workspace/anubis",
-  "postStartCommand": "npm ci && go mod download",
+  "postStartCommand": "bash ./.devcontainer/poststart.sh",
   "features": {
     "ghcr.io/xe/devcontainer-features/ko:1.1.0": {},
     "ghcr.io/devcontainers/features/github-cli:1": {}
@@ -19,8 +21,9 @@
         "golang.go",
         "unifiedjs.vscode-mdx",
         "a-h.templ",
-        "redhat.vscode-yaml"
+        "redhat.vscode-yaml",
+        "streetsidesoftware.code-spell-checker"
       ]
     }
   }
-}
+}

.devcontainer/poststart.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+pwd
+
+npm ci &
+go mod download &
+go install ./utils/cmd/... &
+
+wait

.github/actions/spelling/allow.txt

@@ -3,3 +3,5 @@ https
 ssh
 ubuntu
 workarounds
+rjack
+msgbox

.github/actions/spelling/excludes.txt

@@ -92,3 +92,4 @@ ignore$
 robots.txt
 ^lib/localization/locales/.*\.json$
 ^lib/localization/.*_test.go$
+^test/.*$

.github/actions/spelling/expect.txt

@@ -5,7 +5,6 @@ amazonbot
 anthro
 anubis
 anubistest
-apk
 Applebot
 archlinux
 asnc
@@ -24,6 +23,7 @@ bitrate
 Bluesky
 blueskybot
 boi
+Bokm
 botnet
 botstopper
 BPort
@@ -60,7 +60,6 @@ connnection
 containerbuild
 coreutils
 Cotoyogi
-CRDs
 Cromite
 crt
 Cscript
@@ -131,6 +130,7 @@ Hashcash
 hashrate
 headermap
 healthcheck
+healthz
 hec
 hmc
 hostable
@@ -149,6 +149,7 @@ inp
 internets
 IPTo
 iptoasn
+isp
 iss
 isset
 ivh
@@ -160,7 +161,6 @@ jshelter
 JWTs
 kagi
 kagibot
-keikaku
 Keyfunc
 keypair
 KHTML
@@ -189,7 +189,6 @@ metarefresh
 metrix
 mimi
 Minfilia
-minica
 mistralai
 Mojeek
 mojeekbot
@@ -224,6 +223,7 @@ pipefail
 pki
 podkova
 podman
+poststart
 prebaked
 privkey
 promauto
@@ -243,21 +243,19 @@ redhat
 redir
 redirectscheme
 refactors
-relayd
 reputational
-reqmeta
 risc
 ruleset
 runlevels
 RUnlock
 runtimedir
+runtimedirectory
 sas
 sasl
 searchbot
 searx
 sebest
 secretplans
-selfsigned
 Semrush
 Seo
 setsebool
@@ -300,10 +298,8 @@ uberspace
 Unbreak
 unbreakdocker
 unifiedjs
-unixhttpd
 unmarshal
 unparseable
-uuidgen
 uvx
 UXP
 valkey
@@ -323,11 +319,11 @@ websites
 Webzio
 wildbase
 withthothmock
+wolfbeast
 wordpress
 Workaround
 workdir
 wpbot
-xcaddy
 Xeact
 xeiaso
 xeserv
@@ -344,6 +340,7 @@ yeet
 yeetfile
 yourdomain
 yoursite
+yyz
 Zenos
 zizmor
 zombocom

.github/actions/spelling/patterns.txt

@@ -132,3 +132,7 @@ go install(?:\s+[a-z]+\.[-@\w/.]+)+
 # hit-count: 1 file-count: 1
 # microsoft
 \b(?:https?://|)(?:(?:(?:blogs|download\.visualstudio|docs|msdn2?|research)\.|)microsoft|blogs\.msdn)\.co(?:m|\.\w\w)/[-_a-zA-Z0-9()=./%]*
+
+# hit-count: 1 file-count: 1
+# data url
+\bdata:[-a-zA-Z=;:/0-9+]*,\S*

.github/workflows/docs-deploy.yml

@@ -36,6 +36,9 @@ jobs:
         uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
         with:
           images: ghcr.io/techarohq/anubis/docs
+          tags: |
+            type=sha,enable=true,priority=100,prefix=,suffix=,format=long
+            main
 
       - name: Build and push
         id: build
@@ -50,14 +53,14 @@ jobs:
           push: true
 
       - name: Apply k8s manifests to limsa lominsa
-        uses: actions-hub/kubectl@d50394b7d704525f93faefce1e65a6329ff67271 # v1.33.2
+        uses: actions-hub/kubectl@b5b19eeb6a0ffde16637e398f8b96ef01eb8fdb7 # v1.33.3
         env:
           KUBE_CONFIG: ${{ secrets.LIMSA_LOMINSA_KUBECONFIG }}
         with:
           args: apply -k docs/manifest
 
       - name: Apply k8s manifests to limsa lominsa
-        uses: actions-hub/kubectl@d50394b7d704525f93faefce1e65a6329ff67271 # v1.33.2
+        uses: actions-hub/kubectl@b5b19eeb6a0ffde16637e398f8b96ef01eb8fdb7 # v1.33.3
         env:
           KUBE_CONFIG: ${{ secrets.LIMSA_LOMINSA_KUBECONFIG }}
         with:

.github/workflows/docs-test.yml

@@ -2,7 +2,7 @@ name: Docs test build
 
 on:
   pull_request:
-    branches: [ "main" ]
+    branches: ["main"]
 
 permissions:
   contents: read
@@ -24,7 +24,10 @@ jobs:
         id: meta
         uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
         with:
-          images: ghcr.io/${{ github.repository }}/docs
+          images: ghcr.io/techarohq/anubis/docs
+          tags: |
+            type=sha,enable=true,priority=100,prefix=,suffix=,format=long
+            main
 
       - name: Build and push
         id: build

.github/workflows/package-builds-stable.yml

@@ -1,8 +1,9 @@
 name: Package builds (stable)
 
 on:
-  release:
-    types: [published]
+  workflow_dispatch:
+  # release:
+  #   types: [published]
 
 permissions:
   contents: write
@@ -13,67 +14,67 @@ jobs:
     #runs-on: alrest-techarohq
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      with:
-        persist-credentials: false
-        fetch-tags: true
-        fetch-depth: 0
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          persist-credentials: false
+          fetch-tags: true
+          fetch-depth: 0
 
-    - name: build essential
-      run: |
-        sudo apt-get update
-        sudo apt-get install -y build-essential
+      - name: build essential
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential
 
-    - name: Set up Homebrew
-      uses: Homebrew/actions/setup-homebrew@main
+      - name: Set up Homebrew
+        uses: Homebrew/actions/setup-homebrew@main
 
-    - name: Setup Homebrew cellar cache
-      uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
-      with:
-        path: |
-          /home/linuxbrew/.linuxbrew/Cellar
-          /home/linuxbrew/.linuxbrew/bin
-          /home/linuxbrew/.linuxbrew/etc
-          /home/linuxbrew/.linuxbrew/include
-          /home/linuxbrew/.linuxbrew/lib
-          /home/linuxbrew/.linuxbrew/opt
-          /home/linuxbrew/.linuxbrew/sbin
-          /home/linuxbrew/.linuxbrew/share
-          /home/linuxbrew/.linuxbrew/var
-        key: ${{ runner.os }}-go-homebrew-cellar-${{ hashFiles('go.sum') }}
-        restore-keys: |
-          ${{ runner.os }}-go-homebrew-cellar-
+      - name: Setup Homebrew cellar cache
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: |
+            /home/linuxbrew/.linuxbrew/Cellar
+            /home/linuxbrew/.linuxbrew/bin
+            /home/linuxbrew/.linuxbrew/etc
+            /home/linuxbrew/.linuxbrew/include
+            /home/linuxbrew/.linuxbrew/lib
+            /home/linuxbrew/.linuxbrew/opt
+            /home/linuxbrew/.linuxbrew/sbin
+            /home/linuxbrew/.linuxbrew/share
+            /home/linuxbrew/.linuxbrew/var
+          key: ${{ runner.os }}-go-homebrew-cellar-${{ hashFiles('go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-homebrew-cellar-
 
-    - name: Install Brew dependencies
-      run: |
-        brew bundle
+      - name: Install Brew dependencies
+        run: |
+          brew bundle
 
-    - name: Setup Golang caches
-      uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
-      with:
-        path: |
-          ~/.cache/go-build
-          ~/go/pkg/mod
-        key: ${{ runner.os }}-golang-${{ hashFiles('**/go.sum') }}
-        restore-keys: |
-          ${{ runner.os }}-golang-
+      - name: Setup Golang caches
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ runner.os }}-golang-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-golang-
 
-    - name: install node deps
-      run: |
-        npm ci
+      - name: install node deps
+        run: |
+          npm ci
 
-    - name: Build Packages
-      run: |
-        go tool yeet
+      - name: Build Packages
+        run: |
+          go tool yeet
 
-    - name: Upload released artifacts
-      env:
-        GITHUB_TOKEN: ${{ github.TOKEN }}
-        RELEASE_VERSION: ${{github.event.release.tag_name}}
-      shell: bash
-      run: |
-        RELEASE="${RELEASE_VERSION}"
-        cd var
-        for file in *; do
-          gh release upload $RELEASE $file
-        done
+      - name: Upload released artifacts
+        env:
+          GITHUB_TOKEN: ${{ github.TOKEN }}
+          RELEASE_VERSION: ${{github.event.release.tag_name}}
+        shell: bash
+        run: |
+          RELEASE="${RELEASE_VERSION}"
+          cd var
+          for file in *; do
+            gh release upload $RELEASE $file
+          done

.github/workflows/smoke-tests.yml

@@ -0,0 +1,58 @@
+name: Smoke tests
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+
+permissions:
+  contents: read
+
+jobs:
+  smoke-test:
+    strategy:
+      matrix:
+        test:
+          - git-clone
+          - git-push
+          - healthcheck
+          - i18n
+          - palemoon/amd64
+          #- palemoon/i386
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          persist-credentials: false
+
+      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+        with:
+          node-version: latest
+
+      - uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5.5.0
+        with:
+          go-version: stable
+
+      - uses: ko-build/setup-ko@d006021bd0c28d1ce33a07e7943d48b079944c8d # v0.9
+
+      - name: Install utils
+        run: |
+          go install ./utils/cmd/...
+
+      - name: Run test
+        run: |
+          cd test/${{ matrix.test }}
+          backoff-retry --try-count 10 ./test.sh
+
+      - name: Sanitize artifact name
+        if: always()
+        run: echo "ARTIFACT_NAME=${{ matrix.test }}" | sed 's|/|-|g' >> $GITHUB_ENV
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
+        if: always()
+        with:
+          name: ${{ env.ARTIFACT_NAME }}
+          path: test/${{ matrix.test }}/var

.github/workflows/ssh-ci.yml

@@ -25,13 +25,19 @@ jobs:
           fetch-tags: true
           fetch-depth: 0
           persist-credentials: false
+
       - name: Install CI target SSH key
         uses: shimataro/ssh-key-action@d4fffb50872869abe2d9a9098a6d9c5aa7d16be4 # v2.7.0
         with:
           key: ${{ secrets.CI_SSH_KEY }}
           name: id_rsa
           known_hosts: ${{ secrets.CI_SSH_KNOWN_HOSTS }}
+
+      - uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5.5.0
+        with:
+          go-version: stable
+
       - name: Run CI
-        run: bash test/ssh-ci/rigging.sh ${{ matrix.host }}
+        run: go run ./utils/cmd/backoff-retry bash test/ssh-ci/rigging.sh ${{ matrix.host }}
         env:
           GITHUB_RUN_ID: ${{ github.run_id }}

.github/workflows/zizmor.yml

@@ -21,7 +21,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+        uses: astral-sh/setup-uv@7edac99f961f18b581bbd960d59d049f04c0002f # v6.4.1
 
       - name: Run zizmor 🌈
         run: uvx zizmor --format sarif . > results.sarif 

.vscode/extensions.json

@@ -5,6 +5,7 @@
     "golang.go",
     "unifiedjs.vscode-mdx",
     "a-h.templ",
-    "redhat.vscode-yaml"
+    "redhat.vscode-yaml",
+    "streetsidesoftware.code-spell-checker"
   ]
 }

README.md

@@ -48,6 +48,13 @@ Anubis is brought to you by sponsors and donors like:
     height="64"
   />
 </a>
+<a href="https://fabulous.systems/">
+  <img
+    src="./docs/static/img/sponsors/fabulous-systems.webp"
+    alt="Cat eyes over the word Emma in a serif font"
+    height="64"
+  />
+</a>
 
 ## Overview
 

VERSION

@@ -1 +1 @@
-1.21.0-pre1
+1.21.3

cmd/anubis/main.go

@@ -30,14 +30,16 @@ import (
 	"github.com/TecharoHQ/anubis"
 	"github.com/TecharoHQ/anubis/data"
 	"github.com/TecharoHQ/anubis/internal"
-	"github.com/TecharoHQ/anubis/internal/thoth"
 	libanubis "github.com/TecharoHQ/anubis/lib"
+	"github.com/TecharoHQ/anubis/lib/checker/headerexists"
 	botPolicy "github.com/TecharoHQ/anubis/lib/policy"
 	"github.com/TecharoHQ/anubis/lib/policy/config"
+	"github.com/TecharoHQ/anubis/lib/thoth"
 	"github.com/TecharoHQ/anubis/web"
 	"github.com/facebookgo/flagenv"
 	_ "github.com/joho/godotenv/autoload"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	healthv1 "google.golang.org/grpc/health/grpc_health_v1"
 )
 
 var (
@@ -97,7 +99,7 @@ func keyFromHex(value string) (ed25519.PrivateKey, error) {
 }
 
 func doHealthCheck() error {
-	resp, err := http.Get("http://localhost" + *metricsBind + anubis.BasePrefix + "/metrics")
+	resp, err := http.Get("http://localhost" + *metricsBind + "/healthz")
 	if err != nil {
 		return fmt.Errorf("failed to fetch metrics: %w", err)
 	}
@@ -241,6 +243,15 @@ func main() {
 	}
 
 	internal.InitSlog(*slogLevel)
+	internal.SetHealth("anubis", healthv1.HealthCheckResponse_NOT_SERVING)
+
+	if *healthcheck {
+		log.Println("running healthcheck")
+		if err := doHealthCheck(); err != nil {
+			log.Fatal(err)
+		}
+		return
+	}
 
 	if *extractResources != "" {
 		if err := extractEmbedFS(data.BotPolicies, ".", *extractResources); err != nil {
@@ -253,6 +264,17 @@ func main() {
 		return
 	}
 
+	// install signal handler
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	wg := new(sync.WaitGroup)
+
+	if *metricsBind != "" {
+		wg.Add(1)
+		go metricsServer(ctx, wg.Done)
+	}
+
 	var rp http.Handler
 	// when using anubis via Systemd and environment variables, then it is not possible to set targe to an empty string but only to space
 	if strings.TrimSpace(*target) != "" {
@@ -267,8 +289,6 @@ func main() {
 		log.Fatalf("you can't set COOKIE_DOMAIN and COOKIE_DYNAMIC_DOMAIN at the same time")
 	}
 
-	ctx := context.Background()
-
 	// Thoth configuration
 	switch {
 	case *thothURL != "" && *thothToken == "":
@@ -304,7 +324,7 @@ func main() {
 	if *debugBenchmarkJS {
 		policy.Bots = []botPolicy.Bot{{
 			Name:   "",
-			Rules:  botPolicy.NewHeaderExistsChecker("User-Agent"),
+			Rules:  headerexists.New("User-Agent"),
 			Action: config.RuleBenchmark,
 		}}
 	}
@@ -398,21 +418,12 @@ func main() {
 		log.Fatalf("can't construct libanubis.Server: %v", err)
 	}
 
-	wg := new(sync.WaitGroup)
-	// install signal handler
-	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
-	defer stop()
-
-	if *metricsBind != "" {
-		wg.Add(1)
-		go metricsServer(ctx, wg.Done)
-	}
-
 	var h http.Handler
 	h = s
 	h = internal.RemoteXRealIP(*useRemoteAddress, *bindNetwork, h)
 	h = internal.XForwardedForToXRealIP(h)
 	h = internal.XForwardedForUpdate(*xffStripPrivate, h)
+	h = internal.JA4H(h)
 
 	srv := http.Server{Handler: h, ErrorLog: internal.GetFilteredHTTPLogger()}
 	listener, listenerUrl := setupListener(*bindNetwork, *bind)
@@ -441,6 +452,8 @@ func main() {
 		}
 	}()
 
+	internal.SetHealth("anubis", healthv1.HealthCheckResponse_SERVING)
+
 	if err := srv.Serve(listener); !errors.Is(err, http.ErrServerClosed) {
 		log.Fatal(err)
 	}
@@ -451,20 +464,30 @@ func metricsServer(ctx context.Context, done func()) {
 	defer done()
 
 	mux := http.NewServeMux()
-	mux.Handle(anubis.BasePrefix+"/metrics", promhttp.Handler())
+	mux.Handle("/metrics", promhttp.Handler())
+	mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
+		st, ok := internal.GetHealth("anubis")
+		if !ok {
+			slog.Error("health service anubis does not exist, file a bug")
+		}
+
+		switch st {
+		case healthv1.HealthCheckResponse_NOT_SERVING:
+			http.Error(w, "NOT OK", http.StatusInternalServerError)
+			return
+		case healthv1.HealthCheckResponse_SERVING:
+			fmt.Fprintln(w, "OK")
+			return
+		default:
+			http.Error(w, "UNKNOWN", http.StatusFailedDependency)
+			return
+		}
+	})
 
 	srv := http.Server{Handler: mux, ErrorLog: internal.GetFilteredHTTPLogger()}
 	listener, metricsUrl := setupListener(*metricsBindNetwork, *metricsBind)
 	slog.Debug("listening for metrics", "url", metricsUrl)
 
-	if *healthcheck {
-		log.Println("running healthcheck")
-		if err := doHealthCheck(); err != nil {
-			log.Fatal(err)
-		}
-		return
-	}
-
 	go func() {
 		<-ctx.Done()
 		c, cancel := context.WithTimeout(context.Background(), 5*time.Second)

cmd/robots2policy/main.go

@@ -12,6 +12,7 @@ import (
 	"regexp"
 	"strings"
 
+	"github.com/TecharoHQ/anubis/lib/checker/expression"
 	"github.com/TecharoHQ/anubis/lib/policy/config"
 
 	"sigs.k8s.io/yaml"
@@ -37,11 +38,11 @@ type RobotsRule struct {
 }
 
 type AnubisRule struct {
-	Expression *config.ExpressionOrList `yaml:"expression,omitempty" json:"expression,omitempty"`
-	Challenge  *config.ChallengeRules   `yaml:"challenge,omitempty" json:"challenge,omitempty"`
-	Weight     *config.Weight           `yaml:"weight,omitempty" json:"weight,omitempty"`
-	Name       string                   `yaml:"name" json:"name"`
-	Action     string                   `yaml:"action" json:"action"`
+	Expression *expression.Config     `yaml:"expression,omitempty" json:"expression,omitempty"`
+	Challenge  *config.ChallengeRules `yaml:"challenge,omitempty" json:"challenge,omitempty"`
+	Weight     *config.Weight         `yaml:"weight,omitempty" json:"weight,omitempty"`
+	Name       string                 `yaml:"name" json:"name"`
+	Action     string                 `yaml:"action" json:"action"`
 }
 
 func init() {
@@ -224,11 +225,11 @@ func convertToAnubisRules(robotsRules []RobotsRule) []AnubisRule {
 			}
 
 			if userAgent == "*" {
-				rule.Expression = &config.ExpressionOrList{
+				rule.Expression = &expression.Config{
 					All: []string{"true"}, // Always applies
 				}
 			} else {
-				rule.Expression = &config.ExpressionOrList{
+				rule.Expression = &expression.Config{
 					All: []string{fmt.Sprintf("userAgent.contains(%q)", userAgent)},
 				}
 			}
@@ -249,11 +250,11 @@ func convertToAnubisRules(robotsRules []RobotsRule) []AnubisRule {
 				rule.Name = fmt.Sprintf("%s-global-restriction-%d", *policyName, ruleCounter)
 				rule.Action = "WEIGH"
 				rule.Weight = &config.Weight{Adjust: 20} // Increase difficulty significantly
-				rule.Expression = &config.ExpressionOrList{
+				rule.Expression = &expression.Config{
 					All: []string{"true"}, // Always applies
 				}
 			} else {
-				rule.Expression = &config.ExpressionOrList{
+				rule.Expression = &expression.Config{
 					All: []string{fmt.Sprintf("userAgent.contains(%q)", userAgent)},
 				}
 			}
@@ -285,7 +286,7 @@ func convertToAnubisRules(robotsRules []RobotsRule) []AnubisRule {
 			pathCondition := buildPathCondition(disallow)
 			conditions = append(conditions, pathCondition)
 
-			rule.Expression = &config.ExpressionOrList{
+			rule.Expression = &expression.Config{
 				All: conditions,
 			}
 

data/botPolicies.yaml

@@ -74,13 +74,13 @@ bots:
     weight:
       adjust: 10
 
-  ## System load based checks.
-  # If the system is under high load, add weight.
-  - name: high-load-average
-    action: WEIGH
-    expression: load_1m >= 10.0 # make sure to end the load comparison in a .0
-    weight:
-      adjust: 20
+  # ## System load based checks.
+  # # If the system is under high load, add weight.
+  # - name: high-load-average
+  #   action: WEIGH
+  #   expression: load_1m >= 10.0 # make sure to end the load comparison in a .0
+  #   weight:
+  #     adjust: 20
 
   ## If your backend service is running on the same operating system as Anubis,
   ## you can uncomment this rule to make the challenge easier when the system is

data/services/uptime-robot.yaml

@@ -0,0 +1,223 @@
+- name: uptime-robot
+  user_agent_regex: UptimeRobot
+  action: ALLOW
+  # https://api.uptimerobot.com/meta/ips
+  remote_addresses: [
+    "3.12.251.153/32",
+    "3.20.63.178/32",
+    "3.77.67.4/32",
+    "3.79.134.69/32",
+    "3.105.133.239/32",
+    "3.105.190.221/32",
+    "3.133.226.214/32",
+    "3.149.57.90/32",
+    "3.212.128.62/32",
+    "5.161.61.238/32",
+    "5.161.73.160/32",
+    "5.161.75.7/32",
+    "5.161.113.195/32",
+    "5.161.117.52/32",
+    "5.161.177.47/32",
+    "5.161.194.92/32",
+    "5.161.215.244/32",
+    "5.223.43.32/32",
+    "5.223.53.147/32",
+    "5.223.57.22/32",
+    "18.116.205.62/32",
+    "18.180.208.214/32",
+    "18.192.166.72/32",
+    "18.193.252.127/32",
+    "24.144.78.39/32",
+    "24.144.78.185/32",
+    "34.198.201.66/32",
+    "45.55.123.175/32",
+    "45.55.127.146/32",
+    "49.13.24.81/32",
+    "49.13.130.29/32",
+    "49.13.134.145/32",
+    "49.13.164.148/32",
+    "49.13.167.123/32",
+    "52.15.147.27/32",
+    "52.22.236.30/32",
+    "52.28.162.93/32",
+    "52.59.43.236/32",
+    "52.87.72.16/32",
+    "54.64.67.106/32",
+    "54.79.28.129/32",
+    "54.87.112.51/32",
+    "54.167.223.174/32",
+    "54.249.170.27/32",
+    "63.178.84.147/32",
+    "64.225.81.248/32",
+    "64.225.82.147/32",
+    "69.162.124.227/32",
+    "69.162.124.235/32",
+    "69.162.124.238/32",
+    "78.46.190.63/32",
+    "78.46.215.1/32",
+    "78.47.98.55/32",
+    "78.47.173.76/32",
+    "88.99.80.227/32",
+    "91.99.101.207/32",
+    "128.140.41.193/32",
+    "128.140.106.114/32",
+    "129.212.132.140/32",
+    "134.199.240.137/32",
+    "138.197.53.117/32",
+    "138.197.53.138/32",
+    "138.197.54.143/32",
+    "138.197.54.247/32",
+    "138.197.63.92/32",
+    "139.59.50.44/32",
+    "142.132.180.39/32",
+    "143.198.249.237/32",
+    "143.198.250.89/32",
+    "143.244.196.21/32",
+    "143.244.196.211/32",
+    "143.244.221.177/32",
+    "144.126.251.21/32",
+    "146.190.9.187/32",
+    "152.42.149.135/32",
+    "157.90.155.240/32",
+    "157.90.156.63/32",
+    "159.69.158.189/32",
+    "159.223.243.219/32",
+    "161.35.247.201/32",
+    "167.99.18.52/32",
+    "167.235.143.113/32",
+    "168.119.53.160/32",
+    "168.119.96.239/32",
+    "168.119.123.75/32",
+    "170.64.250.64/32",
+    "170.64.250.132/32",
+    "170.64.250.235/32",
+    "178.156.181.172/32",
+    "178.156.184.20/32",
+    "178.156.185.127/32",
+    "178.156.185.231/32",
+    "178.156.187.238/32",
+    "178.156.189.113/32",
+    "178.156.189.249/32",
+    "188.166.201.79/32",
+    "206.189.241.133/32",
+    "209.38.49.1/32",
+    "209.38.49.206/32",
+    "209.38.49.226/32",
+    "209.38.51.43/32",
+    "209.38.53.7/32",
+    "209.38.124.252/32",
+    "216.144.248.18/31",
+    "216.144.248.21/32",
+    "216.144.248.22/31",
+    "216.144.248.24/30",
+    "216.144.248.28/31",
+    "216.144.248.30/32",
+    "216.245.221.83/32",
+    "2400:6180:10:200::56a0:b000/128",
+    "2400:6180:10:200::56a0:c000/128",
+    "2400:6180:10:200::56a0:e000/128",
+    "2400:6180:100:d0::94b6:4001/128",
+    "2400:6180:100:d0::94b6:5001/128",
+    "2400:6180:100:d0::94b6:7001/128",
+    "2406:da14:94d:8601:9d0d:7754:bedf:e4f5/128",
+    "2406:da14:94d:8601:b325:ff58:2bba:7934/128",
+    "2406:da14:94d:8601:db4b:c5ac:2cbe:9a79/128",
+    "2406:da1c:9c8:dc02:7ae1:f2ea:ab91:2fde/128",
+    "2406:da1c:9c8:dc02:7db9:f38b:7b9f:402e/128",
+    "2406:da1c:9c8:dc02:82b2:f0fd:ee96:579/128",
+    "2600:1f16:775:3a00:ac3:c5eb:7081:942e/128",
+    "2600:1f16:775:3a00:37bf:6026:e54a:f03a/128",
+    "2600:1f16:775:3a00:3f24:5bb0:95d7:5a6b/128",
+    "2600:1f16:775:3a00:8c2c:2ba6:778f:5be5/128",
+    "2600:1f16:775:3a00:91ac:3120:ff38:92b5/128",
+    "2600:1f16:775:3a00:dbbe:36b0:3c45:da32/128",
+    "2600:1f18:179:f900:71:af9a:ade7:d772/128",
+    "2600:1f18:179:f900:2406:9399:4ae6:c5d3/128",
+    "2600:1f18:179:f900:4696:7729:7bb3:f52f/128",
+    "2600:1f18:179:f900:4b7d:d1cc:2d10:211/128",
+    "2600:1f18:179:f900:5c68:91b6:5d75:5d7/128",
+    "2600:1f18:179:f900:e8dd:eed1:a6c:183b/128",
+    "2604:a880:800:14:0:1:68ba:d000/128",
+    "2604:a880:800:14:0:1:68ba:e000/128",
+    "2604:a880:800:14:0:1:68bb:0/128",
+    "2604:a880:800:14:0:1:68bb:1000/128",
+    "2604:a880:800:14:0:1:68bb:3000/128",
+    "2604:a880:800:14:0:1:68bb:4000/128",
+    "2604:a880:800:14:0:1:68bb:5000/128",
+    "2604:a880:800:14:0:1:68bb:6000/128",
+    "2604:a880:800:14:0:1:68bb:7000/128",
+    "2604:a880:800:14:0:1:68bb:a000/128",
+    "2604:a880:800:14:0:1:68bb:b000/128",
+    "2604:a880:800:14:0:1:68bb:c000/128",
+    "2604:a880:800:14:0:1:68bb:d000/128",
+    "2604:a880:800:14:0:1:68bb:e000/128",
+    "2604:a880:800:14:0:1:68bb:f000/128",
+    "2607:ff68:107::4/128",
+    "2607:ff68:107::14/128",
+    "2607:ff68:107::33/128",
+    "2607:ff68:107::48/127",
+    "2607:ff68:107::50/125",
+    "2607:ff68:107::58/127",
+    "2607:ff68:107::60/128",
+    "2a01:4f8:c0c:83fa::1/128",
+    "2a01:4f8:c17:42e4::1/128",
+    "2a01:4f8:c2c:9fc6::1/128",
+    "2a01:4f8:c2c:beae::1/128",
+    "2a01:4f8:1c1a:3d53::1/128",
+    "2a01:4f8:1c1b:4ef4::1/128",
+    "2a01:4f8:1c1b:5b5a::1/128",
+    "2a01:4f8:1c1b:7ecc::1/128",
+    "2a01:4f8:1c1c:11aa::1/128",
+    "2a01:4f8:1c1c:5353::1/128",
+    "2a01:4f8:1c1c:7240::1/128",
+    "2a01:4f8:1c1c:a98a::1/128",
+    "2a01:4f8:c012:c60e::1/128",
+    "2a01:4f8:c013:c18::1/128",
+    "2a01:4f8:c013:34c0::1/128",
+    "2a01:4f8:c013:3b0f::1/128",
+    "2a01:4f8:c013:3c52::1/128",
+    "2a01:4f8:c013:3c53::1/128",
+    "2a01:4f8:c013:3c54::1/128",
+    "2a01:4f8:c013:3c55::1/128",
+    "2a01:4f8:c013:3c56::1/128",
+    "2a01:4ff:f0:bfd::1/128",
+    "2a01:4ff:f0:2219::1/128",
+    "2a01:4ff:f0:3e03::1/128",
+    "2a01:4ff:f0:5f80::1/128",
+    "2a01:4ff:f0:7fad::1/128",
+    "2a01:4ff:f0:9c5f::1/128",
+    "2a01:4ff:f0:b2f2::1/128",
+    "2a01:4ff:f0:b6f1::1/128",
+    "2a01:4ff:f0:d283::1/128",
+    "2a01:4ff:f0:d3cd::1/128",
+    "2a01:4ff:f0:e516::1/128",
+    "2a01:4ff:f0:e9cf::1/128",
+    "2a01:4ff:f0:eccb::1/128",
+    "2a01:4ff:f0:efd1::1/128",
+    "2a01:4ff:f0:fdc7::1/128",
+    "2a01:4ff:2f0:193c::1/128",
+    "2a01:4ff:2f0:27de::1/128",
+    "2a01:4ff:2f0:3b3a::1/128",
+    "2a03:b0c0:2:f0::bd91:f001/128",
+    "2a03:b0c0:2:f0::bd92:1/128",
+    "2a03:b0c0:2:f0::bd92:1001/128",
+    "2a03:b0c0:2:f0::bd92:2001/128",
+    "2a03:b0c0:2:f0::bd92:4001/128",
+    "2a03:b0c0:2:f0::bd92:5001/128",
+    "2a03:b0c0:2:f0::bd92:6001/128",
+    "2a03:b0c0:2:f0::bd92:7001/128",
+    "2a03:b0c0:2:f0::bd92:8001/128",
+    "2a03:b0c0:2:f0::bd92:9001/128",
+    "2a03:b0c0:2:f0::bd92:a001/128",
+    "2a03:b0c0:2:f0::bd92:b001/128",
+    "2a03:b0c0:2:f0::bd92:c001/128",
+    "2a03:b0c0:2:f0::bd92:e001/128",
+    "2a03:b0c0:2:f0::bd92:f001/128",
+    "2a05:d014:1815:3400:6d:9235:c1c0:96ad/128",
+    "2a05:d014:1815:3400:654f:bd37:724c:212b/128",
+    "2a05:d014:1815:3400:90b4:4ef9:5631:b170/128",
+    "2a05:d014:1815:3400:9779:d8e9:100a:9642/128",
+    "2a05:d014:1815:3400:af29:e95e:64ff:df81/128",
+    "2a05:d014:1815:3400:c7d6:f7f3:6cc1:30d1/128",
+    "2a05:d014:1815:3400:d784:e5dd:8e0:67cb/128",
+  ]

docs/.dockerignore

@@ -19,5 +19,3 @@ npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
 
-# Kubernetes manifests
-/manifest

docs/Dockerfile

@@ -7,4 +7,5 @@ RUN npm ci && npm run build
 
 FROM ghcr.io/xe/nginx-micro
 COPY --from=build /app/build /www
+COPY ./manifest/cfg/nginx/nginx.conf /conf
 LABEL org.opencontainers.image.source="https://github.com/TecharoHQ/anubis"

docs/blog/2025-06-27-release-1.20.0/index.mdx

@@ -20,9 +20,9 @@ If you rely on Anubis to keep your website safe, please consider sponsoring the
 
 I am waiting to hear back from NLNet on if Anubis was selected for funding or not. Let's hope it is!
 
-## Deprecation warning: `DEFAULT_DIFFICULTY`
+## Deprecation warning: `DIFFICULTY`
 
-Anubis v1.20.0 is the last version to support the `DEFAULT_DIFFICULTY` flag in the exact way it currently does. In future versions, this will be ineffectual and you should use the [custom threshold system](/docs/admin/configuration/thresholds) instead.
+Anubis v1.20.0 is the last version to support the `DIFFICULTY` flag in the exact way it currently does. In future versions, this will be ineffectual and you should use the [custom threshold system](/docs/admin/configuration/thresholds) instead.
 
 If this becomes an imposition in practice, this will be reverted.
 

docs/blog/2025-07-22-release-1.21.1/index.mdx

@@ -0,0 +1,369 @@
+---
+slug: release/v1.21.1
+title: Anubis v1.21.1 is now available!
+authors: [xe]
+tags: [release]
+image: anubis-i18n.webp
+---
+
+![](./anubis-i18n.webp)
+
+Hey all!
+
+Recently we released [Anubis v1.21.1: Minfilia Warde (Echo 1)](https://github.com/TecharoHQ/anubis/releases/tag/v1.21.1). This is a fairly meaty release and like [last time](../2025-06-27-release-1.20.0/index.mdx) this blogpost will tell you what you need to know before you update. Kick back, get some popcorn and let's dig into this!
+
+{/* truncate */}
+
+In this release, Anubis becomes internationalized, gains the ability to use system load as input to issuing challenges, finally fixes the "invalid response" after "success" bug, and more! Please read these notes before upgrading as the changes are big enough that administrators should take action to ensure that the upgrade goes smoothly.
+
+This release is brought to you by [FreeCAD](https://www.freecad.org/), an open-source computer aided design tool that lets you design things for the real world.
+
+## What's in this release?
+
+The biggest change is that the ["invalid response" after "success" bug](https://github.com/TecharoHQ/anubis/issues/564) is now finally fixed for good by totally rewriting how [Anubis' challenge issuance flow works](#challenge-flow-v2).
+
+This release gives Anubis the following features:
+
+- [Internationalization support](#internationalization), allowing Anubis to render its messages in the human language you speak.
+- Anubis now supports the [`missingHeader`](#missingHeader-function) function to assert the absence of headers in requests.
+- Anubis now has the ability to [store data persistently on the server](#persistent-data-storage).
+- Anubis can use [the system load average](#load-average-checks) as a factor to determine if it needs to filter traffic or not.
+- Add `COOKIE_SECURE` option to set the cookie [Secure flag](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Cookies#block_access_to_your_cookies)
+- Sets cookie defaults to use [SameSite: None](https://web.dev/articles/samesite-cookies-explained)
+- Allow [Common Crawl](https://commoncrawl.org/) by default so scrapers have less incentive to scrape
+- Add `/healthz` metrics route for use in platform-based health checks.
+- Start exposing JA4H fingerprints for later use in CEL expressions.
+
+And this release also fixes the following bugs:
+
+- [Challenge issuance has been totally rewritten](#challenge-flow-v2) to finally squash the infamous ["invalid response" after "success" bug](https://github.com/TecharoHQ/anubis/issues/564) for good.
+- In order to reduce confusion, the "Success" interstitial that shows up when you pass a proof of work challenge has been removed.
+- Don't block Anubis starting up if [Thoth](/docs/admin/thoth/) health checks fail.
+- The "Try again" button on the error page has been fixed. Previously it meant "try the solution again" instead of "try the challenge again".
+- In certain cases, a user could be stuck with a test cookie that is invalid, locking them out of the service for up to half an hour. This has been fixed with better validation of this case and clearing the cookie.
+- "Proof of work" has been removed from the branding due to some users having extremely negative connotations with it.
+
+We try to avoid introducing breaking changes as much as possible, but these are the changes that may be relevant for you as an administrator:
+
+- The [challenge format](#challenge-format-change) has been changed in order to account for [the new challenge issuance flow](#challenge-flow-v2).
+- The [systemd service `RuntimeDirectory` has been changed](#breaking-change-systemd-runtimedirectory-change).
+
+### Sponsoring the project
+
+If you rely on Anubis to keep your website safe, please consider sponsoring the project on [GitHub Sponsors](https://github.com/sponsors/Xe) or [Patreon](https://patreon.com/cadey). Funding helps pay hosting bills and offset the time spent on making this project the best it can be. Every little bit helps and when enough money is raised, [I can make Anubis my full-time job](https://github.com/TecharoHQ/anubis/discussions/278).
+
+Once this pie chart is at 100%, I can start to reduce my hours at my day job as most of my needs will be met (pre-tax):
+
+```mermaid
+pie title Funding update
+    "GitHub Sponsors" : 29
+    "Patreon" : 14
+    "Remaining" : 56
+```
+
+I am waiting to hear back from NLNet on if Anubis was selected for funding or not. Let's hope it is!
+
+## New features
+
+### Internationalization
+
+Anubis now supports localized responses. Locales can be added in [lib/localization/locales/](https://github.com/TecharoHQ/anubis/tree/main/lib/localization/locales). This release includes support for the following languages:
+
+- [Brazilian Portugese](https://github.com/TecharoHQ/anubis/pull/726)
+- [Chinese (Simplified)](https://github.com/TecharoHQ/anubis/pull/774)
+- [Chinese (Traditional)](https://github.com/TecharoHQ/anubis/pull/759)
+- [Czech](https://github.com/TecharoHQ/anubis/pull/849)
+- English
+- [Estonian](https://github.com/TecharoHQ/anubis/pull/783)
+- [Filipino](https://github.com/TecharoHQ/anubis/pull/775)
+- [Finnish](https://github.com/TecharoHQ/anubis/pull/863)
+- [French](https://github.com/TecharoHQ/anubis/pull/716)
+- [German](https://github.com/TecharoHQ/anubis/pull/741)
+- [Japanese](https://github.com/TecharoHQ/anubis/pull/772)
+- [Icelandic](https://github.com/TecharoHQ/anubis/pull/780)
+- [Italian](https://github.com/TecharoHQ/anubis/pull/778)
+- [Norwegian](https://github.com/TecharoHQ/anubis/pull/855)
+- [Russian](https://github.com/TecharoHQ/anubis/pull/882)
+- [Spanish](https://github.com/TecharoHQ/anubis/pull/716)
+- [Turkish](https://github.com/TecharoHQ/anubis/pull/751)
+
+If facts or local regulations demand, you can set Anubis default language with the `FORCED_LANGUAGE` environment variable or the `--forced-language` command line argument:
+
+```sh
+FORCED_LANGUAGE=de
+```
+
+## Big ticket bug fixes
+
+These issues affect every user of Anubis. Administrators should upgrade Anubis as soon as possible to mitigate them.
+
+### Fix event loop thrashing when solving a proof of work challenge
+
+Anubis has a progress bar so that users can have something moving while it works. This gives users more confidence that something is happening and that the website is not being malicious with CPU usage. However, the way it was implemented way back in [#87](https://github.com/TecharoHQ/anubis/pull/87) had a subtle bug:
+
+```js
+if (
+  (nonce > oldNonce) | 1023 && // we've wrapped past 1024
+  (nonce >> 10) % threads === threadId // and it's our turn
+) {
+  postMessage(nonce);
+}
+```
+
+The logic here looks fine but is subtly wrong as was reported in [#877](https://github.com/TecharoHQ/anubis/issues/877) by the main Pale Moon developer.
+
+For context, `nonce` is a counter that increments by the worker count every loop. This is intended to spread the load between CPU cores as such:
+
+| Iteration | Worker ID | Nonce |
+| :-------- | :-------- | :---- |
+| 1         | 0         | 0     |
+| 1         | 1         | 1     |
+| 2         | 0         | 2     |
+| 2         | 1         | 3     |
+
+And so on. This makes the proof of work challenge as fast as it can possibly be so that Anubis quickly goes away and you can enjoy the service it is protecting.
+
+The incorrect part of this is the boolean logic, specifically the part with the bitwise or `|`. I think the intent was to use a logical or (`||`), but this had the effect of making the `postMessage` handler fire on every iteration. The intent of this snippet (as the comment clearly indicates) is to make sure that the main event loop is only updated with the worker status every 1024 iterations per worker. This had the opposite effect, causing a lot of messages to be sent from workers to the parent JavaScript context.
+
+This is bad for the event loop.
+
+Instead, I have ripped out that statement and replaced it with a much simpler increment only counter that fires every 1024 iterations. Additionally, only the first thread communicates back to the parent process. This does mean that in theory the other workers could be ahead of the first thread (posting a message out of a worker has a nonzero cost), but in practice I don't think this will be as much of an issue as the current behaviour is.
+
+The root cause of the stack exhaustion is likely the pressure caused by all of the postMessage futures piling up. Maybe the larger stack size in 64 bit environments is causing this to be fine there, maybe it's some combination of newer hardware in 64 bit systems making this not be as much of a problem due to it being able to handle events fast enough to keep up with the pressure.
+
+Either way, thanks much to [@wolfbeast](https://github.com/wolfbeast) and the Pale Moon community for finding this. This will make Anubis faster for everyone!
+
+### Fix potential memory leak when discovering a solution
+
+In some cases, the parallel solution finder in Anubis could cause all of the worker promises to leak due to the fact the promises were being improperly terminated. A recursion bomb happens in the following scenario:
+
+1. A worker sends a message indicating it found a solution to the proof of work challenge.
+2. The `onmessage` handler for that worker calls `terminate()`
+3. Inside `terminate()`, the parent process loops through all other workers and calls `w.terminate()` on them.
+4. It's possible that terminating a worker could lead to the `onerror` event handler.
+5. This would create a recursive loop of `onmessage` -> `terminate` -> `onerror` -> `terminate` -> `onerror` and so on.
+
+This infinite recursion quickly consumes all available stack space, but this has never been noticed in development because all of my computers have at least 64Gi of ram provisioned to them under the axiom paying for more ram is cheaper than paying in my time spent having to work around not having enough ram. Additionally, ia32 has a smaller base stack size, which means that they will run into this issue much sooner than users on other CPU architectures will.
+
+The fix adds a boolean `settled` flag to prevent termination from running more than once.
+
+## Expressions features
+
+Anubis v1.21.1 adds additional [expressions](/docs/admin/configuration/expressions) features so that you can make your request matching even more granular.
+
+### `missingHeader` function
+
+Anubis [expressions](/docs/admin/configuration/expressions) have [a few functions exposed](/docs/admin/configuration/expressions/#functions-exposed-to-anubis-expressions). Anubis v1.21.1 adds the `missingHeader` function, allowing you to assert the _absence_ of a header in requests.
+
+Let's say you're getting a lot of requests from clients that are pretending to be Google Chrome. Google Chrome sends a few signals to web servers, the main one of them is the [`Sec-Ch-Ua`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Sec-CH-UA). Sec-CH-UA is part of Google's [User Agent Client Hints](https://wicg.github.io/ua-client-hints/#sec-ch-ua) proposal, but it being present is a sign that the client is more likely Google Chrome than not. With the `missingHeader` function, you can write a rule to [add weight](/docs/admin/policies/#request-weight) to requests without `Sec-Ch-Ua` that claim to be Google Chrome.
+
+```yaml
+# Adds weight clients that claim to be Google Chrome without setting Sec-Ch-Ua
+- name: old-chrome
+  action: WEIGH
+  weight:
+    adjust: 10
+  expression:
+    all:
+      - userAgent.matches("Chrome/[1-9][0-9]?\\.0\\.0\\.0")
+      - missingHeader(headers, "Sec-Ch-Ua")
+```
+
+When combined with [weight thresholds](/docs/admin/configuration/thresholds), this allows you to make requests that don't match the signature of Google Chrome more suspicious, which will make them have a more difficult challenge.
+
+### Load average checks
+
+Anubis can dynamically take action [based on the system load average](/docs/admin/configuration/expressions/#using-the-system-load-average), allowing you to write rules like this:
+
+```yaml
+## System load based checks.
+# If the system is under high load for the last minute, add weight.
+- name: high-load-average
+  action: WEIGH
+  expression: load_1m >= 10.0 # make sure to end the load comparison in a .0
+  weight:
+    adjust: 20
+
+# If it is not for the last 15 minutes, remove weight.
+- name: low-load-average
+  action: WEIGH
+  expression: load_15m <= 4.0 # make sure to end the load comparison in a .0
+  weight:
+    adjust: -10
+```
+
+Something to keep in mind about system load average is that it is not aware of the number of cores the system has. If you have a 16 core system that has 16 processes running but none of them is hogging the CPU, then you will get a load average below 16. If you are in doubt, make your "high load" metric at least two times the number of CPU cores and your "low load" metric at least half of the number of CPU cores. For example:
+
+|      Kind | Core count | Load threshold |
+| --------: | :--------- | :------------- |
+| high load | 4          | `8.0`          |
+|  low load | 4          | `2.0`          |
+| high load | 16         | `32.0`         |
+|  low load | 16         | `8`            |
+
+Also keep in mind that this does not account for other kinds of latency like I/O latency or downstream API response latency. A system can have its web applications unresponsive due to high latency from a MySQL server but still have that web application server report a load near or at zero.
+
+:::note
+
+This does not work if you are using Kubernetes.
+
+:::
+
+When combined with [weight thresholds](/docs/admin/configuration/thresholds), this allows you to make incoming sessions "back off" while the server is under high load.
+
+## Challenge flow v2
+
+The main goal of Anubis is to weigh the risks of incoming requests in order to protect upstream resources against abusive clients like badly written scrapers. In order to separate "good" clients (like users wanting to learn from a website's content) from "bad" clients, Anubis issues [challenges](/docs/category/challenges).
+
+Previously the Anubis challenge flow looked like this:
+
+```mermaid
+---
+title: Old Anubis challenge flow
+---
+flowchart LR
+    user(User Browser)
+    subgraph Anubis
+        mIC{Challenge?}
+        ic(Issue Challenge)
+        rp(Proxy to service)
+        mIC -->|User needs a challenge| ic
+        mIC -->|User does not need a challenge| rp
+    end
+    target(Target Service)
+    rp --> target
+    user --> mIC
+    ic -->|Pass a challenge| user
+    target -->|Site data| users
+```
+
+In order to issue a challenge, Anubis generated a challenge string based on request metadata that we assumed wouldn't drastically change between requests, including but not limited to:
+
+- The client's User-Agent string.
+- The client [`Accept-Language` header](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Accept-Language) value.
+- The client's IP address.
+
+Anubis also didn't store any information about challenges so that it can remain lightweight and handle the onslaught of requests from scrapers. The assumption was that the challenge string function was idempotent per client across time. What actually ended up happening was something like this:
+
+```mermaid
+---
+title: Anubis challenge string idempotency
+---
+sequenceDiagram
+    User->>+Anubis: GET /wiki/some-page
+    Anubis->>+Make Challenge: Generate a challenge string
+    Make Challenge->>-Anubis: Challenge string: taco salad
+    Anubis->>-User: HTTP 401 solve a challenge
+    User->>+Anubis: GET internal-api/pass-challenge
+    Anubis->>+Make Challenge: Generate a challenge string
+    Make Challenge->>-Anubis: Challenge string: burrito bar
+    Anubis->>+User: Error: invalid response
+```
+
+Various attempts were made to fix this. All of these ended up failing. Many difficulties were discovered including but not limited to:
+
+- Removing `Accept-Language` from consideration because [Chrome randomizes the contents of `Accept-Language` to reduce fingerprinting](https://github.com/explainers-by-googlers/reduce-accept-language), a behaviour which [causes a lot of confusion](https://www.reddit.com/r/chrome/comments/nhpnez/google_chrome_is_randomly_switching_languages_on/) for users with multiple system languages selected.
+- [IPv6 privacy extensions](https://www.internetsociety.org/resources/deploy360/2014/privacy-extensions-for-ipv6-slaac/) mean that each request could be coming from a different IP address (at least one legitimate user in the wild has been observed to have a different IP address per TCP session across an entire `/48`).
+- Some [US mobile phone carriers make it too easy for your IP address to drastically change](https://news.ycombinator.com/item?id=32038215) without user input.
+- [Happy eyeballs](https://en.wikipedia.org/wiki/Happy_Eyeballs) means that some requests can come in over IPv4 and some requests can come in over IPv6.
+- To make things worse, you can't even assert that users are from the same [BGP autonomous system](<https://en.wikipedia.org/wiki/Autonomous_system_(Internet)>) because some users could have ISPs that are IPv4 only, forcing them to use a different IP address space to get IPv6 internet access. This sounds like it's rare enough, but I personally have to do this even though I pay for 8 gigabit fiber from my ISP and only get IPv4 service from them.
+
+Amusingly enough, the only part of this that has survived is the assertion that a user hasn't changed their `User-Agent` string. Maybe [that one guy that sets his Chrome version to `150`](https://github.com/TecharoHQ/anubis/issues/239) would have issues, but so far I've not seen any evidence that a client randomly changing their user agent between challenge issuance and solving can possibly be legitimate.
+
+As a result, the entire subsystem that generated challenges before had to be ripped out and rewritten from scratch.
+
+It was replaced with a new flow that stores data on the server side, compares that data against what the client responds with, and then checks pass/fail that way:
+
+```mermaid
+---
+title: New challenge flow
+---
+sequenceDiagram
+    User->>+Anubis: GET /wiki/some-page
+    Anubis->>+Make Challenge: Generate a challenge string
+    Make Challenge->>+Store: Store info for challenge 1234
+    Make Challenge->>-Anubis: Challenge string: taco salad, ID 1234
+    Anubis->>-User: HTTP 401 solve a challenge
+    User->>+Anubis: GET internal-api/pass-challenge, challenge 1234
+    Anubis->>+Validate Challenge: verify challenge 1234
+    Validate Challenge->>+Store: Get info for challenge 1234
+    Store->>-Validate Challenge: Here you go!
+    Validate Challenge->>-Anubis: Valid ✅
+    Anubis->>+User: Here's a cookie to get past Anubis
+```
+
+As a result, the [challenge format](#challenge-format-change) had to change. Old cookies will still be validated, but the next minor version (v1.22.0) will include validation to ensure that all challenges are accounted for on the server side. This data is stored in the active [storage backend](/docs/admin/policies/#storage-backends) for up to 30 minutes. This also fixes [#746](https://github.com/TecharoHQ/anubis/issues/746) and other similar instances of this issue.
+
+### Challenge format change
+
+Previously Anubis did no accounting for challenges that it issued. This means that if Anubis restarted during a client, the client would be able to proceed once Anubis came back online.
+
+During the upgrade to v1.21.0 and when v1.21.0 (or later) restarts with the [in-memory storage backend](/docs/admin/policies/#memory), you may see a higher rate of failed challenges than normal. If this persists beyond a few minutes, [open an issue](https://github.com/TecharoHQ/anubis/issues/new).
+
+If you are using the in-memory storage backend, please consider using [a different storage backend](/docs/admin/policies/#storage-backends).
+
+### Storage
+
+Anubis offers a few different storage backends depending on your needs:
+
+| Backend                                  | Description                                                                                                    |
+| :--------------------------------------- | :------------------------------------------------------------------------------------------------------------- |
+| [`memory`](/docs/admin/policies/#memory) | An in-memory hashmap that is cleared when Anubis is restarted.                                                 |
+| [`bbolt`](/docs/admin/policies/#bbolt)   | A memory-mapped key/value store that can persist between Anubis restarts.                                      |
+| [`valkey`](/docs/admin/policies/#valkey) | A networked key/value store that can persist between Anubis restarts and coordinate across multiple instances. |
+
+Please review the documentation for each storage method to figure out the one best for your needs. If you aren't sure, consult this diagram:
+
+```mermaid
+---
+title: What storage backend do I need?
+---
+flowchart TD
+    OneInstance{Do you only have
+one instance of
+Anubis?}
+    Persistence{Do you have
+persistent disk
+access in your
+environment?}
+    bbolt[(bbolt)]
+    memory[(memory)]
+    valkey[(valkey)]
+    OneInstance -->|Yes| Persistence
+    OneInstance -->|No| valkey
+    Persistence -->|Yes| bbolt
+    Persistence -->|No| memory
+```
+
+## Breaking change: systemd `RuntimeDirectory` change
+
+The following potentially breaking change applies to native installs with systemd only:
+
+Each instance of systemd service template now has a unique `RuntimeDirectory`, as opposed to each instance of the service sharing a `RuntimeDirectory`. This change was made to avoid [the `RuntimeDirectory` getting nuked](https://github.com/TecharoHQ/anubis/issues/748) any time one of the Anubis instances restarts.
+
+If you configured Anubis' unix sockets to listen on `/run/anubis/foo.sock` for instance `anubis@foo`, you will need to configure Anubis to listen on `/run/anubis/foo/foo.sock` and additionally configure your HTTP load balancer as appropriate.
+
+If you need the legacy behaviour, install this [systemd unit dropin](https://www.flatcar.org/docs/latest/setup/systemd/drop-in-units/):
+
+```systemd
+# /etc/systemd/system/anubis@.service.d/50-runtimedir.conf
+[Service]
+RuntimeDirectory=anubis
+```
+
+Just keep in mind that this will cause problems when Anubis restarts.
+
+## What's up next?
+
+The biggest things we want to do in the next release (in no particular order):
+
+- A rewrite of bot checking rule configuration syntax to make it less ambiguous.
+- [JA4](https://blog.foxio.io/ja4+-network-fingerprinting) (and other forms of) fingerprinting and coordination with [Thoth](/docs/admin/thoth/) to allow clients with high aggregate pass rates through without seeing Anubis at all.
+- Advanced heuristics for [users of the unbranded variant of Anubis](/docs/admin/botstopper/).
+- Optimize the release flow so that releases can be triggered and executed by continuous integration tools. The ultimate goal is to make it possible to release Anubis in 15 minutes after pressing a single "mint release" button.
+- Add "hot reloading" support to Anubis, allowing administrators to update the rules without restarting the service.
+- Fix [multiple slash support](https://github.com/TecharoHQ/anubis/issues/754) for web applications that require optional path variables.
+- Add weight to "brand new" clients.
+- Implement a "maze" feature that tries to get crawlers ensnared in a maze of random links so that clients that are more than 20 links in can be reported to the home base.
+- Open [Thoth-based advanced checks](/docs/admin/thoth/) to more users with an easier onboarding flow.
+- More smoke tests including for browsers like [Pale Moon](https://www.palemoon.org/).

docs/docs/CHANGELOG.md

@@ -13,17 +13,73 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 <!-- This changes the project to: -->
 
+- The [Thoth client](https://anubis.techaro.lol/docs/admin/thoth) is now public in the repo instead of being an internal package.
+
+## v1.21.3: Minfilia Warde - Echo 3
+
+### Fixes
+
+#### Fixes a problem with nonstandard URLs and redirects
+
+Fixes [GHSA-jhjj-2g64-px7c](https://github.com/TecharoHQ/anubis/security/advisories/GHSA-jhjj-2g64-px7c).
+
+This could allow an attacker to craft an Anubis pass-challenge URL that forces a redirect to nonstandard URLs, such as the `javascript:` scheme which executes arbitrary JavaScript code in a browser context when the user clicks the "Try again" button.
+
+This has been fixed by disallowing any URLs without the scheme `http` or `https`.
+
+Additionally, the "Try again" button has been fixed to completely ignore the user-supplied redirect location. It now redirects to the home page (`/`).
+
+## v1.21.2: Minfilia Warde - Echo 2
+
+This contained an incomplete fix for [GHSA-jhjj-2g64-px7c](https://github.com/TecharoHQ/anubis/security/advisories/GHSA-jhjj-2g64-px7c). Do not use this version.
+
+## v1.21.1: Minfilia Warde - Echo 1
+
+- Expired records are now properly removed from bbolt databases ([#848](https://github.com/TecharoHQ/anubis/pull/848)).
+- Fix hanging on service restart ([#853](https://github.com/TecharoHQ/anubis/issues/853))
+
 ### Added
 
+Anubis now supports the [`missingHeader`](./admin/configuration/expressions.mdx#missingHeader) to assert the absence of headers in requests.
+
+#### New locales
+
 Anubis now supports these new languages:
 
-- [Italian](https://github.com/TecharoHQ/anubis/pull/778)
+- [Czech](https://github.com/TecharoHQ/anubis/pull/849)
+- [Finnish](https://github.com/TecharoHQ/anubis/pull/863)
+- [Norwegian Bokmål](https://github.com/TecharoHQ/anubis/pull/855)
+- [Norwegian Nynorsk](https://github.com/TecharoHQ/anubis/pull/855)
+- [Russian](https://github.com/TecharoHQ/anubis/pull/882)
+
+### Fixes
+
+#### Fix ["error: can't get challenge"](https://github.com/TecharoHQ/anubis/issues/869) when details about a challenge can't be found in the server side state
+
+v1.21.0 changed the core challenge flow to maintain information about challenges on the server side instead of only doing them via stateless idempotent generation functions and relying on details to not change. There was a subtle bug introduced in this change: if a client has an unknown challenge ID set in its test cookie, Anubis will clear that cookie and then throw an HTTP 500 error.
+
+This has been fixed by making Anubis throw a new challenge page instead.
+
+#### Fix event loop thrashing when solving a proof of work challenge
+
+Previously the "fast" proof of work solver had a fragment of JavaScript that attempted to only post an update about proof of work progress to the main browser window every 1024 iterations. This fragment of JavaScript was subtly incorrect in a way that passed review but actually made the workers send an update back to the main thread every iteration. This caused a pileup of unhandled async calls (similar to a socket accept() backlog pileup in Unix) that caused stack space exhaustion.
+
+This has been fixed in the following ways:
+
+1. The complicated boolean logic has been totally removed in favour of a worker-local iteration counter.
+2. The progress bar is updated by worker `0` instead of all workers.
+
+Hopefully this should limit the event loop thrashing and let ia32 browsers (as well as any environment with a smaller stack size than amd64 and aarch64 seem to have) function normally when processing Anubis proof of work challenges.
+
+#### Fix potential memory leak when discovering a solution
+
+In some cases, the parallel solution finder in Anubis could cause all of the worker promises to leak due to the fact the promises were being improperly terminated. This was fixed by having Anubis debounce worker termination instead of allowing it to potentially recurse infinitely.
 
 ## v1.21.0: Minfilia Warde
 
 > Please, be at ease. You are among friends here.
 
-In this release, Anubis becomes internationalized, gains the ability to use system load as input to issuing challenges,
+In this release, Anubis becomes internationalized, gains the ability to use system load as input to issuing challenges, finally fixes the "invalid response" after "success" bug, and more! Please read these notes before upgrading as the changes are big enough that administrators should take action to ensure that the upgrade goes smoothly.
 
 ### Big ticket changes
 
@@ -40,11 +96,16 @@ Anubis now is able to store things persistently [in memory](./admin/policies.mdx
 Anubis now supports localized responses. Locales can be added in [lib/localization/locales/](https://github.com/TecharoHQ/anubis/tree/main/lib/localization/locales). This release includes support for the following languages:
 
 - [Brazilian Portugese](https://github.com/TecharoHQ/anubis/pull/726)
+- [Chinese (Simplified)](https://github.com/TecharoHQ/anubis/pull/774)
 - [Chinese (Traditional)](https://github.com/TecharoHQ/anubis/pull/759)
 - English
 - [Estonian](https://github.com/TecharoHQ/anubis/pull/783)
+- [Filipino](https://github.com/TecharoHQ/anubis/pull/775)
 - [French](https://github.com/TecharoHQ/anubis/pull/716)
 - [German](https://github.com/TecharoHQ/anubis/pull/741)
+- [Icelandic](https://github.com/TecharoHQ/anubis/pull/780)
+- [Italian](https://github.com/TecharoHQ/anubis/pull/778)
+- [Japanese](https://github.com/TecharoHQ/anubis/pull/772)
 - [Spanish](https://github.com/TecharoHQ/anubis/pull/716)
 - [Turkish](https://github.com/TecharoHQ/anubis/pull/751)
 
@@ -100,9 +161,26 @@ There are a bunch of other assorted features and fixes too:
 - Allow [Common Crawl](https://commoncrawl.org/) by default so scrapers have less incentive to scrape
 - The [bbolt storage backend](./admin/policies.mdx#bbolt) now runs its cleanup every hour instead of every five minutes.
 - Don't block Anubis starting up if [Thoth](./admin/thoth.mdx) health checks fail.
+- A race condition involving [opening two challenge pages at once in different tabs](https://github.com/TecharoHQ/anubis/issues/832) causing one of them to fail has been fixed.
+- The "Try again" button on the error page has been fixed. Previously it meant "try the solution again" instead of "try the challenge again".
+- In certain cases, a user could be stuck with a test cookie that is invalid, locking them out of the service for up to half an hour. This has been fixed with better validation of this case and clearing the cookie.
+- Start exposing JA4H fingerprints for later use in CEL expressions.
+- Add `/healthz` route for use in platform-based health checks.
 
 ### Potentially breaking changes
 
+We try to introduce breaking changes as much as possible, but these are the changes that may be relevant for you as an administrator:
+
+#### Challenge format change
+
+Previously Anubis did no accounting for challenges that it issued. This means that if Anubis restarted during a client, the client would be able to proceed once Anubis came back online.
+
+During the upgrade to v1.21.0 and when v1.21.0 (or later) restarts with the [in-memory storage backend](./admin/policies.mdx#memory), you may see a higher rate of failed challenges than normal. If this persists beyond a few minutes, [open an issue](https://github.com/TecharoHQ/anubis/issues/new).
+
+If you are using the in-memory storage backend, please consider using [a different storage backend](./admin/policies.mdx#storage-backends).
+
+#### Systemd service changes
+
 The following potentially breaking change applies to native installs with systemd only:
 
 Each instance of systemd service template now has a unique `RuntimeDirectory`, as opposed to each instance of the service sharing a `RuntimeDirectory`. This change was made to avoid [the `RuntimeDirectory` getting nuked any time one of the Anubis instances restarts](https://github.com/TecharoHQ/anubis/issues/748).

docs/docs/admin/configuration/expressions.mdx

@@ -77,7 +77,7 @@ For example, consider this rule:
 
 For this rule, if a request comes in from `8.8.8.8` or `1.1.1.1`, Anubis will deny the request and return an error page.
 
-#### `all` blocks
+### `all` blocks
 
 An `all` block that contains a list of expressions. If all expressions in the list return `true`, then the action specified in the rule will be taken. If any of the expressions in the list returns `false`, Anubis will move on to the next rule.
 
@@ -123,7 +123,7 @@ In order to avoid this, make sure the header or query parameter you are testing
     - 'path == "/index.php"'
     - '"title" in query'
     - '"action" in query'
-    - 'query["action"] == "history"
+    - 'query["action"] == "history"'
 ```
 
 This rule throws a challenge if and only if all of the following conditions are true:
@@ -186,8 +186,32 @@ Also keep in mind that this does not account for other kinds of latency like I/O
 
 Anubis expressions can be augmented with the following functions:
 
+### `missingHeader`
+
+Available in `bot` expressions.
+
+```ts
+function missingHeader(headers: Record<string, string>, key: string) bool
+```
+
+`missingHeader` returns `true` if the request does not contain a header. This is useful when you are trying to assert behavior such as:
+
+```yaml
+# Adds weight to old versions of Chrome
+- name: old-chrome
+  action: WEIGH
+  weight:
+    adjust: 10
+  expression:
+    all:
+      - userAgent.matches("Chrome/[1-9][0-9]?\\.0\\.0\\.0")
+      - missingHeader(headers, "Sec-Ch-Ua")
+```
+
 ### `randInt`
 
+Available in all expressions.
+
 ```ts
 function randInt(n: int): int;
 ```

docs/docs/admin/environments/docker-compose.mdx

@@ -4,7 +4,7 @@ Docker compose is typically used in concert with other load balancers such as [A
 
 ```yaml
 services:
-  anubis-nginx:
+  anubis:
     image: ghcr.io/techarohq/anubis:latest
     environment:
       BIND: ":8080"
@@ -15,10 +15,17 @@ services:
       POLICY_FNAME: "/data/cfg/botPolicy.yaml"
       OG_PASSTHROUGH: "true"
       OG_EXPIRY_TIME: "24h"
+    healthcheck:
+      test: ["CMD", "anubis", "--healthcheck"]
+      interval: 5s
+      timeout: 30s
+      retries: 5
+      start_period: 500ms
     ports:
       - 8080:8080
     volumes:
       - "./botPolicy.yaml:/data/cfg/botPolicy.yaml:ro"
+
   nginx:
     image: nginx
     volumes:

docs/docs/admin/environments/nginx.mdx

@@ -79,6 +79,10 @@ server {
   root "/srv/http/anubistest.techaro.lol";
   index index.html;
 
+  # Get the visiting IP from the TLS termination server
+  set_real_ip_from unix:;
+  real_ip_header   X-Real-IP;
+  
   # Your normal configuration can go here
   # location .php { fastcgi...} etc.
 }

docs/docs/admin/native-install.mdx

@@ -137,7 +137,7 @@ Test to make sure it's running with `curl`:
 curl http://localhost:8240/metrics
 ```
 
-Then set up your reverse proxy (Nginx, Caddy, etc.) to point to the Anubis port. Anubis will then reverse proxy all requests that meet the policies in `/etc/anubis/gitea.botPolicies.json` to the target service.
+Then set up your reverse proxy (Nginx, Caddy, etc.) to point to the Anubis port. Anubis will then reverse proxy all requests that meet the policies in `/etc/anubis/gitea.botPolicies.yaml` to the target service.
 
 For more details on particular reverse proxies, see here:
 

docs/docs/admin/policies.mdx

@@ -268,6 +268,12 @@ The memory backend is an in-memory cache. This backend works best if you don't u
 
 The biggest downside is that there is not currently a limit to how much data can be stored in memory. This will be addressed at a later time.
 
+:::warning
+
+The in-memory backend exists mostly for validation, testing, and to ensure that the default configuration of Anubis works as expected. Do not use this persistently in production.
+
+:::
+
 #### Configuration
 
 The memory backend does not require any configuration to use.

docs/docs/index.mdx

@@ -65,6 +65,13 @@ Anubis is brought to you by sponsors and donors like:
     height="64"
   />
 </a>
+<a href="https://fabulous.systems/">
+  <img
+    src="/img/sponsors/fabulous-systems.webp"
+    alt="Cat eyes over the word Emma in a serif font"
+    height="64"
+  />
+</a>
 
 ## Overview
 

docs/docs/user/known-instances.md

@@ -53,6 +53,11 @@ This page contains a non-exhaustive list with all websites using Anubis.
 - https://marginalia-search.com/
 - https://repositorio.ufrn.br/home/
 - https://mozillazine.org/
+- https://clew.se/
+- https://tumfatig.net/
+- https://rpmfusion.org/
+- https://wiki.freepascal.org/
+- https://azurlane.koumakan.jp/
 - <details>
   <summary>FreeCAD</summary>
   - https://forum.freecad.org/
@@ -101,3 +106,10 @@ This page contains a non-exhaustive list with all websites using Anubis.
   <summary>Forschungszentrum Jülich</summary>
   - https://juser.fz-juelich.de/
   </details>
+- <details>
+  <summary>archlinux32.org</summary>
+  - https://www.archlinux32.org/packages/
+  - https://bbs.archlinux32.org/
+  - https://bugs.archlinux32.org/
+  </details>
+

docs/docusaurus.config.ts

@@ -139,6 +139,10 @@ const config: Config = {
               label: 'GitHub',
               href: 'https://github.com/TecharoHQ/anubis',
             },
+            {
+              label: 'Status',
+              href: 'https://techarohq.github.io/status/'
+            },
           ],
         },
       ],

docs/fly.toml

@@ -0,0 +1,19 @@
+app = 'anubis-docs'
+primary_region = 'yyz'
+
+[build]
+  image = "ghcr.io/techarohq/anubis/docs:main"
+
+[http_service]
+  internal_port = 80
+  force_https = true
+  auto_stop_machines = true
+  auto_start_machines = true
+  min_machines_running = 0
+  processes = ['app']
+
+[[vm]]
+  cpu_kind = 'shared'
+  cpus = 1
+  memory_mb = 256
+

docs/manifest/cfg/nginx/mime.types

@@ -0,0 +1,99 @@
+
+types {
+  text/html html htm shtml;
+  text/css css;
+  text/xml xml;
+  image/gif gif;
+  image/jpeg jpeg jpg;
+  application/javascript js;
+  application/atom+xml atom;
+  application/rss+xml rss;
+
+  text/mathml mml;
+  text/plain txt;
+  text/vnd.sun.j2me.app-descriptor jad;
+  text/vnd.wap.wml wml;
+  text/x-component htc;
+
+  image/avif avif;
+  image/png png;
+  image/svg+xml svg svgz;
+  image/tiff tif tiff;
+  image/vnd.wap.wbmp wbmp;
+  image/webp webp;
+  image/x-icon ico;
+  image/x-jng jng;
+  image/x-ms-bmp bmp;
+
+  font/woff woff;
+  font/woff2 woff2;
+
+  application/java-archive jar war ear;
+  application/json json;
+  application/mac-binhex40 hqx;
+  application/msword doc;
+  application/pdf pdf;
+  application/postscript ps eps ai;
+  application/rtf rtf;
+  application/vnd.apple.mpegurl m3u8;
+  application/vnd.google-earth.kml+xml kml;
+  application/vnd.google-earth.kmz kmz;
+  application/vnd.ms-excel xls;
+  application/vnd.ms-fontobject eot;
+  application/vnd.ms-powerpoint ppt;
+  application/vnd.oasis.opendocument.graphics odg;
+  application/vnd.oasis.opendocument.presentation odp;
+  application/vnd.oasis.opendocument.spreadsheet ods;
+  application/vnd.oasis.opendocument.text odt;
+  application/vnd.openxmlformats-officedocument.presentationml.presentation
+  pptx;
+  application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
+  xlsx;
+  application/vnd.openxmlformats-officedocument.wordprocessingml.document
+  docx;
+  application/vnd.wap.wmlc wmlc;
+  application/wasm wasm;
+  application/x-7z-compressed 7z;
+  application/x-cocoa cco;
+  application/x-java-archive-diff jardiff;
+  application/x-java-jnlp-file jnlp;
+  application/x-makeself run;
+  application/x-perl pl pm;
+  application/x-pilot prc pdb;
+  application/x-rar-compressed rar;
+  application/x-redhat-package-manager rpm;
+  application/x-sea sea;
+  application/x-shockwave-flash swf;
+  application/x-stuffit sit;
+  application/x-tcl tcl tk;
+  application/x-x509-ca-cert der pem crt;
+  application/x-xpinstall xpi;
+  application/xhtml+xml xhtml;
+  application/xspf+xml xspf;
+  application/zip zip;
+
+  application/octet-stream bin exe dll;
+  application/octet-stream deb;
+  application/octet-stream dmg;
+  application/octet-stream iso img;
+  application/octet-stream msi msp msm;
+
+  audio/midi mid midi kar;
+  audio/mpeg mp3;
+  audio/ogg ogg;
+  audio/x-m4a m4a;
+  audio/x-realaudio ra;
+
+  video/3gpp 3gpp 3gp;
+  video/mp2t ts;
+  video/mp4 mp4;
+  video/mpeg mpeg mpg;
+  video/quicktime mov;
+  video/webm webm;
+  video/x-flv flv;
+  video/x-m4v m4v;
+  video/x-mng mng;
+  video/x-ms-asf asx asf;
+  video/x-ms-wmv wmv;
+  video/x-msvideo avi;
+}

docs/manifest/cfg/nginx/nginx.conf

@@ -0,0 +1,31 @@
+user nginx;
+worker_processes 2;
+error_log /dev/stdout warn;
+pid /nginx.pid;
+
+events {
+  worker_connections 1024;
+}
+
+http {
+  include mime.types;
+  default_type application/octet-stream;
+  access_log /dev/stdout;
+
+  sendfile on;
+  keepalive_timeout 65;
+
+  server {
+    listen 80 default_server;
+    server_name _;
+
+    error_page 404 /404.html;
+
+    root /www;
+    index index.html;
+
+    location / {
+      try_files $uri $uri/ =404;
+    }
+  }
+}

docs/manifest/deployment.yaml

@@ -15,6 +15,9 @@ spec:
         - name: anubis
           configMap:
             name: anubis-cfg
+        - name: nginx
+          configMap:
+            name: nginx-cfg
         - name: temporary-data
           emptyDir: {}
       containers:
@@ -28,8 +31,23 @@ spec:
             requests:
               cpu: 250m
               memory: 128Mi
+          volumeMounts:
+            - name: nginx
+              mountPath: /conf
           ports:
             - containerPort: 80
+          readinessProbe:
+            httpGet:
+              path: /
+              port: 80
+            initialDelaySeconds: 1
+            periodSeconds: 10
+          livenessProbe:
+            httpGet:
+              path: /
+              port: 80
+            initialDelaySeconds: 10
+            periodSeconds: 20
         - name: anubis
           image: ghcr.io/techarohq/anubis:main
           imagePullPolicy: Always
@@ -75,3 +93,15 @@ spec:
           envFrom:
             - secretRef:
                 name: anubis-docs-thoth
+          readinessProbe:
+            httpGet:
+              path: /healthz
+              port: 9090
+            initialDelaySeconds: 1
+            periodSeconds: 10
+          livenessProbe:
+            httpGet:
+              path: /healthz
+              port: 9090
+            initialDelaySeconds: 10
+            periodSeconds: 20

docs/manifest/kustomization.yaml

@@ -11,3 +11,8 @@ configMapGenerator:
     behavior: create
     files:
       - ./cfg/anubis/botPolicies.yaml
+  - name: nginx-cfg
+    behavior: create
+    files:
+      - ./cfg/nginx/mime.types
+      - ./cfg/nginx/nginx.conf

docs/package-lock.json

@@ -5908,9 +5908,9 @@
       }
     },
     "node_modules/brace-expansion": {
-      "version": "1.1.11",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-      "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
+      "version": "1.1.12",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz",
+      "integrity": "sha512-9T9UjW3r0UW5c1Q7GTwllptXwhvYmEzFhzMfZ9H7FQWt+uZePjZPjBP/W1ZEyZ1twGWom5/56TF4lPcqjnDHcg==",
       "license": "MIT",
       "dependencies": {
         "balanced-match": "^1.0.0",
@@ -6496,16 +6496,16 @@
       }
     },
     "node_modules/compression": {
-      "version": "1.8.0",
-      "resolved": "https://registry.npmjs.org/compression/-/compression-1.8.0.tgz",
-      "integrity": "sha512-k6WLKfunuqCYD3t6AsuPGvQWaKwuLLh2/xHNcX4qE+vIfDNXpSqnrhwA7O53R7WVQUnt8dVAIW+YHr7xTgOgGA==",
+      "version": "1.8.1",
+      "resolved": "https://registry.npmjs.org/compression/-/compression-1.8.1.tgz",
+      "integrity": "sha512-9mAqGPHLakhCLeNyxPkK4xVo746zQ/czLH1Ky+vkitMnWfWZps8r0qXuwhwizagCRttsL4lfG4pIOvaWLpAP0w==",
       "license": "MIT",
       "dependencies": {
         "bytes": "3.1.2",
         "compressible": "~2.0.18",
         "debug": "2.6.9",
         "negotiator": "~0.6.4",
-        "on-headers": "~1.0.2",
+        "on-headers": "~1.1.0",
         "safe-buffer": "5.2.1",
         "vary": "~1.1.2"
       },
@@ -13562,9 +13562,9 @@
       }
     },
     "node_modules/on-headers": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/on-headers/-/on-headers-1.0.2.tgz",
-      "integrity": "sha512-pZAE+FJLoyITytdqK0U5s+FIpjN0JP3OzFi/u8Rx+EV5/W+JTWGXG8xFzevE7AjBfDqHv/8vL8qQsIhHnqRkrA==",
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/on-headers/-/on-headers-1.1.0.tgz",
+      "integrity": "sha512-737ZY3yNnXy37FHkQxPzt4UZ2UWPWiCZWLvFZ4fu5cueciegX0zGPnrlY6bwRg4FdQOe9YU8MkmJwGhoMybl8A==",
       "license": "MIT",
       "engines": {
         "node": ">= 0.8"

errors.go

@@ -0,0 +1,7 @@
+package anubis
+
+import "errors"
+
+var (
+	ErrMisconfiguration = errors.New("[unexpected] policy: administrator misconfiguration")
+)

go.mod

@@ -7,13 +7,14 @@ require (
 	github.com/a-h/templ v0.3.906
 	github.com/cespare/xxhash/v2 v2.3.0
 	github.com/facebookgo/flagenv v0.0.0-20160425205200-fcd59fca7456
-	github.com/gaissmai/bart v0.20.4
+	github.com/gaissmai/bart v0.20.5
 	github.com/golang-jwt/jwt/v5 v5.2.2
 	github.com/google/cel-go v0.25.0
 	github.com/google/uuid v1.6.0
 	github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.1.0
 	github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.3.2
 	github.com/joho/godotenv v1.5.1
+	github.com/lum8rjack/go-ja4h v0.0.0-20250606032308-3a989c6635be
 	github.com/nicksnyder/go-i18n/v2 v2.6.0
 	github.com/playwright-community/playwright-go v0.5200.0
 	github.com/prometheus/client_golang v1.22.0
@@ -22,8 +23,8 @@ require (
 	github.com/shirou/gopsutil/v4 v4.25.6
 	github.com/testcontainers/testcontainers-go v0.37.0
 	go.etcd.io/bbolt v1.4.2
-	golang.org/x/net v0.41.0
-	golang.org/x/text v0.26.0
+	golang.org/x/net v0.42.0
+	golang.org/x/text v0.27.0
 	google.golang.org/grpc v1.73.0
 	gopkg.in/yaml.v3 v3.0.1
 	k8s.io/apimachinery v0.33.2
@@ -157,15 +158,15 @@ require (
 	go.opentelemetry.io/proto/otlp v1.7.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.2 // indirect
 	go.yaml.in/yaml/v3 v3.0.3 // indirect
-	golang.org/x/crypto v0.39.0 // indirect
+	golang.org/x/crypto v0.40.0 // indirect
 	golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 // indirect
 	golang.org/x/exp/typeparams v0.0.0-20231108232855-2478ac86f678 // indirect
 	golang.org/x/mod v0.25.0 // indirect
 	golang.org/x/oauth2 v0.28.0 // indirect
-	golang.org/x/sync v0.15.0 // indirect
-	golang.org/x/sys v0.33.0 // indirect
+	golang.org/x/sync v0.16.0 // indirect
+	golang.org/x/sys v0.34.0 // indirect
 	golang.org/x/telemetry v0.0.0-20240522233618-39ace7a40ae7 // indirect
-	golang.org/x/term v0.32.0 // indirect
+	golang.org/x/term v0.33.0 // indirect
 	golang.org/x/tools v0.34.0 // indirect
 	golang.org/x/vuln v1.1.4 // indirect
 	golang.org/x/xerrors v0.0.0-20240716161551-93cc26a95ae9 // indirect

go.sum

@@ -133,8 +133,8 @@ github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHk
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/fsnotify/fsnotify v1.8.0 h1:dAwr6QBTBZIkG8roQaJjGof0pp0EeF+tNV7YBP3F/8M=
 github.com/fsnotify/fsnotify v1.8.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
-github.com/gaissmai/bart v0.20.4 h1:Ik47r1fy3jRVU+1eYzKSW3ho2UgBVTVnUS8O993584U=
-github.com/gaissmai/bart v0.20.4/go.mod h1:cEed+ge8dalcbpi8wtS9x9m2hn/fNJH5suhdGQOHnYk=
+github.com/gaissmai/bart v0.20.5 h1:ehoWZWQ7j//qt0K0Zs4i9hpoPpbgqsMQiR8W2QPJh+c=
+github.com/gaissmai/bart v0.20.5/go.mod h1:cEed+ge8dalcbpi8wtS9x9m2hn/fNJH5suhdGQOHnYk=
 github.com/gliderlabs/ssh v0.3.8 h1:a4YXD1V7xMF9g5nTkdfnja3Sxy1PVDCj1Zg4Wb8vY6c=
 github.com/gliderlabs/ssh v0.3.8/go.mod h1:xYoytBv1sV0aL3CavoDuJIQNURXkkfPA/wxQ1pL1fAU=
 github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 h1:+zs/tPmkDkHx3U66DAb0lQFJrpS6731Oaa12ikc+DiI=
@@ -253,6 +253,8 @@ github.com/leodido/go-urn v1.2.0 h1:hpXL4XnriNwQ/ABnpepYM/1vCLWNDfUNts8dX3xTG6Y=
 github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 h1:6E+4a0GO5zZEnZ81pIr0yLvtUWk2if982qA3F3QD6H4=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0/go.mod h1:zJYVVT2jmtg6P3p1VtQj7WsuWi/y4VnjVBn7F8KPB3I=
+github.com/lum8rjack/go-ja4h v0.0.0-20250606032308-3a989c6635be h1:dVIND0nXGXPQnFZYrMXT6CxHhBYhTPMm0GFqcmfaIC4=
+github.com/lum8rjack/go-ja4h v0.0.0-20250606032308-3a989c6635be/go.mod h1:q68TUR45WDa2r3yU4aO6WgxfCc0Vj1qtRaKaRE3yMLM=
 github.com/magiconair/properties v1.8.10 h1:s31yESBquKXCV9a/ScB3ESkOjUYYv+X0rg8SYxI99mE=
 github.com/magiconair/properties v1.8.10/go.mod h1:Dhd985XPs7jluiymwWYZ0G4Z61jb3vdS329zhj2hYo0=
 github.com/matryer/is v1.4.0 h1:sosSmIWwkYITGrxZ25ULNDeKiMNzFSr4V/eqBQP0PeE=
@@ -427,8 +429,8 @@ golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/crypto v0.19.0/go.mod h1:Iy9bg/ha4yyC70EfRS8jz+B6ybOBKMaSxLj6P6oBDfU=
-golang.org/x/crypto v0.39.0 h1:SHs+kF4LP+f+p14esP5jAoDpHU8Gu/v9lFRK6IT5imM=
-golang.org/x/crypto v0.39.0/go.mod h1:L+Xg3Wf6HoL4Bn4238Z6ft6KfEpN0tJGo53AAPC632U=
+golang.org/x/crypto v0.40.0 h1:r4x+VvoG5Fm+eJcxMaY8CQM7Lb0l1lsmjGBQ6s8BfKM=
+golang.org/x/crypto v0.40.0/go.mod h1:Qr1vMER5WyS2dfPHAlsOj01wgLbsyWtFn/aY+5+ZdxY=
 golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 h1:2dVuKD2vS7b0QIHQbpyTISPd0LeHDbnYEryqj5Q1ug8=
 golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56/go.mod h1:M4RDyNAINzryxdtnbRXRL/OHtkFuWGRjvuhBJpk2IlY=
 golang.org/x/exp/typeparams v0.0.0-20231108232855-2478ac86f678 h1:1P7xPZEwZMoBoz0Yze5Nx2/4pxj6nw9ZqHWXqP0iRgQ=
@@ -448,8 +450,8 @@ golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qx
 golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
 golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
 golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
-golang.org/x/net v0.41.0 h1:vBTly1HeNPEn3wtREYfy4GZ/NECgw2Cnl+nK6Nz3uvw=
-golang.org/x/net v0.41.0/go.mod h1:B/K4NNqkfmg07DQYrbwvSluqCJOOXwUjeb/5lOisjbA=
+golang.org/x/net v0.42.0 h1:jzkYrhi3YQWD6MLBJcsklgQsoAcw89EcZbJw8Z614hs=
+golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/oauth2 v0.28.0 h1:CrgCKl8PPAVtLnU3c+EDw6x11699EWlsDeWNWKdIOkc=
 golang.org/x/oauth2 v0.28.0/go.mod h1:onh5ek6nERTohokkhCD/y2cV4Do3fxFHFuAejCkRWT8=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -457,8 +459,8 @@ golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.15.0 h1:KWH3jNZsfyT6xfAfKiz6MRNmd46ByHDYaZ7KSkCtdW8=
-golang.org/x/sync v0.15.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
+golang.org/x/sync v0.16.0 h1:ycBJEhp9p4vXvUZNszeOq0kGTPghopOL8q0fq3vstxw=
+golang.org/x/sync v0.16.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -485,8 +487,8 @@ golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
-golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
+golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/telemetry v0.0.0-20240522233618-39ace7a40ae7 h1:FemxDzfMUcK2f3YY4H+05K9CDzbSVr2+q/JKN45pey0=
 golang.org/x/telemetry v0.0.0-20240522233618-39ace7a40ae7/go.mod h1:pRgIJT+bRLFKnoM1ldnzKoxTIn14Yxz928LQRYYgIN0=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -494,8 +496,8 @@ golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuX
 golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
 golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
 golang.org/x/term v0.17.0/go.mod h1:lLRBjIVuehSbZlaOtGMbcMncT+aqLLLmKrsjNrUguwk=
-golang.org/x/term v0.32.0 h1:DR4lr0TjUs3epypdhTOkMmuF5CDFJ/8pOnbzMZPQ7bg=
-golang.org/x/term v0.32.0/go.mod h1:uZG1FhGx848Sqfsq4/DlJr3xGGsYMu/L5GW4abiaEPQ=
+golang.org/x/term v0.33.0 h1:NuFncQrRcaRvVmgRkvM3j/F00gWIAlcmlB8ACEKmGIg=
+golang.org/x/term v0.33.0/go.mod h1:s18+ql9tYWp1IfpV9DmCtQDDSRBUjKaw9M1eAv5UeF0=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
@@ -504,8 +506,8 @@ golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/text v0.26.0 h1:P42AVeLghgTYr4+xUnTRKDMqpar+PtX7KWuNQL21L8M=
-golang.org/x/text v0.26.0/go.mod h1:QK15LZJUUQVJxhz7wXgxSy/CJaTFjd0G+YLonydOVQA=
+golang.org/x/text v0.27.0 h1:4fGWRpyh641NLlecmyl4LOe6yDdfaYNrGb2zdfo4JV4=
+golang.org/x/text v0.27.0/go.mod h1:1D28KMCvyooCX9hBiosv5Tz/+YLxj0j7XhWjpSUF7CU=
 golang.org/x/time v0.9.0 h1:EsRrnYcQiGH+5FfbgvV4AP7qEZstoyrHB0DzarOQ4ZY=
 golang.org/x/time v0.9.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

internal/health.go

@@ -0,0 +1,25 @@
+package internal
+
+import (
+	"context"
+
+	"google.golang.org/grpc/health"
+	healthv1 "google.golang.org/grpc/health/grpc_health_v1"
+)
+
+var HealthSrv = health.NewServer()
+
+func SetHealth(svc string, status healthv1.HealthCheckResponse_ServingStatus) {
+	HealthSrv.SetServingStatus(svc, status)
+}
+
+func GetHealth(svc string) (healthv1.HealthCheckResponse_ServingStatus, bool) {
+	st, err := HealthSrv.Check(context.Background(), &healthv1.HealthCheckRequest{
+		Service: svc,
+	})
+	if err != nil {
+		return healthv1.HealthCheckResponse_UNKNOWN, false
+	}
+
+	return st.GetStatus(), true
+}

internal/ja4h.go

@@ -0,0 +1,14 @@
+package internal
+
+import (
+	"net/http"
+
+	"github.com/lum8rjack/go-ja4h"
+)
+
+func JA4H(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		r.Header.Add("X-Http-Fingerprint-JA4H", ja4h.JA4H(r))
+		next.ServeHTTP(w, r)
+	})
+}

lib/anubis.go

@@ -28,15 +28,17 @@ import (
 	"github.com/TecharoHQ/anubis/internal/dnsbl"
 	"github.com/TecharoHQ/anubis/internal/ogtags"
 	"github.com/TecharoHQ/anubis/lib/challenge"
+	"github.com/TecharoHQ/anubis/lib/checker"
 	"github.com/TecharoHQ/anubis/lib/localization"
 	"github.com/TecharoHQ/anubis/lib/policy"
-	"github.com/TecharoHQ/anubis/lib/policy/checker"
 	"github.com/TecharoHQ/anubis/lib/policy/config"
 	"github.com/TecharoHQ/anubis/lib/store"
 
+	// checker implementations
+	_ "github.com/TecharoHQ/anubis/lib/checker/all"
+
 	// challenge implementations
-	_ "github.com/TecharoHQ/anubis/lib/challenge/metarefresh"
-	_ "github.com/TecharoHQ/anubis/lib/challenge/proofofwork"
+	_ "github.com/TecharoHQ/anubis/lib/challenge/all"
 )
 
 var (
@@ -102,6 +104,10 @@ func (s *Server) challengeFor(r *http.Request) (*challenge.Challenge, error) {
 	ckie := ckies[0]
 	chall, err := j.Get(r.Context(), "challenge:"+ckie.Value)
 	if err != nil {
+		if errors.Is(err, store.ErrNotFound) {
+			return s.issueChallenge(r.Context(), r)
+		}
+
 		return nil, err
 	}
 
@@ -380,6 +386,23 @@ func (s *Server) PassChallenge(w http.ResponseWriter, r *http.Request) {
 	lg := internal.GetRequestLogger(r)
 	localizer := localization.GetLocalizer(r)
 
+	redir := r.FormValue("redir")
+	redirURL, err := url.ParseRequestURI(redir)
+	if err != nil {
+		lg.Error("invalid redirect", "err", err)
+		s.respondWithStatus(w, r, localizer.T("invalid_redirect"), http.StatusBadRequest)
+		return
+	}
+
+	switch redirURL.Scheme {
+	case "", "http", "https":
+		// allowed
+	default:
+		lg.Error("XSS attempt blocked, invalid redirect scheme", "scheme", redirURL.Scheme)
+		s.respondWithStatus(w, r, localizer.T("invalid_redirect"), http.StatusBadRequest)
+		return
+	}
+
 	// Adjust cookie path if base prefix is not empty
 	cookiePath := "/"
 	if anubis.BasePrefix != "" {
@@ -394,15 +417,6 @@ func (s *Server) PassChallenge(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	s.ClearCookie(w, CookieOpts{Name: anubis.TestCookieName, Host: r.Host})
-
-	redir := r.FormValue("redir")
-	redirURL, err := url.ParseRequestURI(redir)
-	if err != nil {
-		lg.Error("invalid redirect", "err", err)
-		s.respondWithError(w, r, localizer.T("invalid_redirect"))
-		return
-	}
 	// used by the path checker rule
 	r.URL = redirURL
 
@@ -537,7 +551,7 @@ func (s *Server) check(r *http.Request) (policy.CheckResult, *policy.Bot, error)
 		if matches {
 			return cr("threshold/"+t.Name, t.Action, weight), &policy.Bot{
 				Challenge: t.Challenge,
-				Rules:     &checker.List{},
+				Rules:     &checker.Any{},
 			}, nil
 		}
 	}
@@ -548,6 +562,6 @@ func (s *Server) check(r *http.Request) (policy.CheckResult, *policy.Bot, error)
 			ReportAs:   s.policy.DefaultDifficulty,
 			Algorithm:  config.DefaultAlgorithm,
 		},
-		Rules: &checker.List{},
+		Rules: &checker.Any{},
 	}, nil
 }

lib/anubis_test.go

@@ -1,8 +1,10 @@
 package lib
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -15,9 +17,9 @@ import (
 	"github.com/TecharoHQ/anubis"
 	"github.com/TecharoHQ/anubis/data"
 	"github.com/TecharoHQ/anubis/internal"
-	"github.com/TecharoHQ/anubis/internal/thoth/thothmock"
 	"github.com/TecharoHQ/anubis/lib/policy"
 	"github.com/TecharoHQ/anubis/lib/policy/config"
+	"github.com/TecharoHQ/anubis/lib/thoth/thothmock"
 )
 
 func init() {
@@ -736,3 +738,230 @@ func TestStripBasePrefixFromRequest(t *testing.T) {
 		})
 	}
 }
+
+// TestChallengeFor_ErrNotFound makes sure that users with invalid challenge IDs
+// in the test cookie don't get rejected by the database lookup failing.
+func TestChallengeFor_ErrNotFound(t *testing.T) {
+	pol := loadPolicies(t, "testdata/aggressive_403.yaml", 0)
+	ckieExpiration := 10 * time.Minute
+	const wrongCookie = "wrong cookie"
+
+	srv := spawnAnubis(t, Options{
+		Next:   http.NewServeMux(),
+		Policy: pol,
+
+		CookieDomain:     "127.0.0.1",
+		CookieExpiration: ckieExpiration,
+	})
+
+	req := httptest.NewRequest("GET", "http://example.com/", nil)
+	req.Header.Set("X-Real-IP", "127.0.0.1")
+	req.Header.Set("User-Agent", "CHALLENGE")
+	req.AddCookie(&http.Cookie{Name: anubis.TestCookieName, Value: wrongCookie})
+
+	w := httptest.NewRecorder()
+	srv.maybeReverseProxyOrPage(w, req)
+
+	resp := w.Result()
+	defer resp.Body.Close()
+
+	body := new(strings.Builder)
+	_, err := io.Copy(body, resp.Body)
+	if err != nil {
+		t.Fatalf("reading body should not fail: %v", err)
+	}
+
+	t.Run("make sure challenge page is issued", func(t *testing.T) {
+		if !strings.Contains(body.String(), "anubis_challenge") {
+			t.Error("should get a challenge page")
+		}
+
+		if resp.StatusCode != http.StatusUnauthorized {
+			t.Errorf("should get a 401 Unauthorized, got: %d", resp.StatusCode)
+		}
+	})
+
+	t.Run("make sure that the body is not an error page", func(t *testing.T) {
+		if strings.Contains(body.String(), "reject.webp") {
+			t.Error("should not get an internal server error")
+		}
+	})
+
+	t.Run("make sure new test cookie is issued", func(t *testing.T) {
+		found := false
+		for _, cookie := range resp.Cookies() {
+			if cookie.Name == anubis.TestCookieName {
+				if cookie.Value == wrongCookie {
+					t.Error("a new challenge cookie should be issued")
+				}
+				found = true
+			}
+		}
+		if !found {
+			t.Error("a new test cookie should be set")
+		}
+	})
+}
+
+func TestPassChallengeXSS(t *testing.T) {
+	pol := loadPolicies(t, "", anubis.DefaultDifficulty)
+
+	srv := spawnAnubis(t, Options{
+		Next:   http.NewServeMux(),
+		Policy: pol,
+	})
+
+	ts := httptest.NewServer(internal.RemoteXRealIP(true, "tcp", srv))
+	defer ts.Close()
+
+	cli := httpClient(t)
+	chall := makeChallenge(t, ts, cli)
+
+	testCases := []struct {
+		name  string
+		redir string
+	}{
+		{
+			name:  "javascript alert",
+			redir: "javascript:alert('xss')",
+		},
+		{
+			name:  "vbscript",
+			redir: "vbscript:msgbox(\"XSS\")",
+		},
+		{
+			name:  "data url",
+			redir: "data:text/html;base64,PHNjcmlwdD5hbGVydCgneHNzJyk8L3NjcmlwdD4=",
+		},
+	}
+
+	t.Run("with test cookie", func(t *testing.T) {
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				nonce := 0
+				elapsedTime := 420
+				calculated := ""
+				calcString := fmt.Sprintf("%s%d", chall.Challenge, nonce)
+				calculated = internal.SHA256sum(calcString)
+
+				req, err := http.NewRequest(http.MethodGet, ts.URL+"/.within.website/x/cmd/anubis/api/pass-challenge", nil)
+				if err != nil {
+					t.Fatalf("can't make request: %v", err)
+				}
+
+				q := req.URL.Query()
+				q.Set("response", calculated)
+				q.Set("nonce", fmt.Sprint(nonce))
+				q.Set("redir", tc.redir)
+				q.Set("elapsedTime", fmt.Sprint(elapsedTime))
+				req.URL.RawQuery = q.Encode()
+
+				u, err := url.Parse(ts.URL)
+				if err != nil {
+					t.Fatal(err)
+				}
+
+				for _, ckie := range cli.Jar.Cookies(u) {
+					if ckie.Name == anubis.TestCookieName {
+						req.AddCookie(ckie)
+					}
+				}
+
+				resp, err := cli.Do(req)
+				if err != nil {
+					t.Fatalf("can't do request: %v", err)
+				}
+
+				body, _ := io.ReadAll(resp.Body)
+
+				if bytes.Contains(body, []byte(tc.redir)) {
+					t.Log(string(body))
+					t.Error("found XSS in HTML body")
+				}
+
+				if resp.StatusCode != http.StatusBadRequest {
+					t.Errorf("wanted status %d, got %d. body: %s", http.StatusBadRequest, resp.StatusCode, body)
+				}
+			})
+		}
+	})
+
+	t.Run("no test cookie", func(t *testing.T) {
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				nonce := 0
+				elapsedTime := 420
+				calculated := ""
+				calcString := fmt.Sprintf("%s%d", chall.Challenge, nonce)
+				calculated = internal.SHA256sum(calcString)
+
+				req, err := http.NewRequest(http.MethodGet, ts.URL+"/.within.website/x/cmd/anubis/api/pass-challenge", nil)
+				if err != nil {
+					t.Fatalf("can't make request: %v", err)
+				}
+
+				q := req.URL.Query()
+				q.Set("response", calculated)
+				q.Set("nonce", fmt.Sprint(nonce))
+				q.Set("redir", tc.redir)
+				q.Set("elapsedTime", fmt.Sprint(elapsedTime))
+				req.URL.RawQuery = q.Encode()
+
+				resp, err := cli.Do(req)
+				if err != nil {
+					t.Fatalf("can't do request: %v", err)
+				}
+
+				body, _ := io.ReadAll(resp.Body)
+
+				if bytes.Contains(body, []byte(tc.redir)) {
+					t.Log(string(body))
+					t.Error("found XSS in HTML body")
+				}
+
+				if resp.StatusCode != http.StatusBadRequest {
+					t.Errorf("wanted status %d, got %d. body: %s", http.StatusBadRequest, resp.StatusCode, body)
+				}
+			})
+		}
+	})
+}
+
+func TestXForwardedForNoDoubleComma(t *testing.T) {
+	var h http.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("X-Forwarded-For", r.Header.Get("X-Forwarded-For"))
+		fmt.Fprintln(w, "OK")
+	})
+
+	h = internal.XForwardedForToXRealIP(h)
+	h = internal.XForwardedForUpdate(false, h)
+
+	pol := loadPolicies(t, "testdata/permissive.yaml", 4)
+
+	srv := spawnAnubis(t, Options{
+		Next:   h,
+		Policy: pol,
+	})
+	ts := httptest.NewServer(srv)
+	t.Cleanup(ts.Close)
+
+	req, err := http.NewRequest(http.MethodGet, ts.URL, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	req.Header.Set("X-Real-Ip", "10.0.0.1")
+
+	resp, err := ts.Client().Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		t.Errorf("response status is wrong, wanted %d but got: %s", http.StatusOK, resp.Status)
+	}
+
+	if xff := resp.Header.Get("X-Forwarded-For"); strings.HasPrefix(xff, ",,") {
+		t.Errorf("X-Forwarded-For has two leading commas: %q", xff)
+	}
+}

lib/challenge/all/all.go

@@ -0,0 +1,6 @@
+package all
+
+import (
+	_ "github.com/TecharoHQ/anubis/lib/challenge/metarefresh"
+	_ "github.com/TecharoHQ/anubis/lib/challenge/proofofwork"
+)

lib/checker/all.go

@@ -0,0 +1,35 @@
+package checker
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/TecharoHQ/anubis/internal"
+)
+
+type All []Interface
+
+func (a All) Check(r *http.Request) (bool, error) {
+	for _, c := range a {
+		match, err := c.Check(r)
+		if err != nil {
+			return match, err
+		}
+		if !match {
+			return false, err // no match
+		}
+	}
+
+	return true, nil // match
+}
+
+func (a All) Hash() string {
+	var sb strings.Builder
+
+	for _, c := range a {
+		fmt.Fprintln(&sb, c.Hash())
+	}
+
+	return internal.FastHash(sb.String())
+}

lib/checker/all/all.go

@@ -0,0 +1,10 @@
+// Package all imports all of the standard checker types.
+package all
+
+import (
+	_ "github.com/TecharoHQ/anubis/lib/checker/expression"
+	_ "github.com/TecharoHQ/anubis/lib/checker/headerexists"
+	_ "github.com/TecharoHQ/anubis/lib/checker/headermatches"
+	_ "github.com/TecharoHQ/anubis/lib/checker/path"
+	_ "github.com/TecharoHQ/anubis/lib/checker/remoteaddress"
+)

lib/checker/all_test.go

@@ -0,0 +1,70 @@
+package checker
+
+import (
+	"net/http"
+	"testing"
+)
+
+func TestAll_Check(t *testing.T) {
+	tests := []struct {
+		name     string
+		checkers []MockChecker
+		want     bool
+		wantErr  bool
+	}{
+		{
+			name: "All match",
+			checkers: []MockChecker{
+				{Result: true, Err: nil},
+				{Result: true, Err: nil},
+			},
+			want:    true,
+			wantErr: false,
+		},
+		{
+			name: "One not match",
+			checkers: []MockChecker{
+				{Result: true, Err: nil},
+				{Result: false, Err: nil},
+			},
+			want:    false,
+			wantErr: false,
+		},
+		{
+			name: "No match",
+			checkers: []MockChecker{
+				{Result: false, Err: nil},
+				{Result: false, Err: nil},
+			},
+			want:    false,
+			wantErr: false,
+		},
+		{
+			name: "Error encountered",
+			checkers: []MockChecker{
+				{Result: true, Err: nil},
+				{Result: false, Err: http.ErrNotSupported},
+			},
+			want:    false,
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var all All
+			for _, mc := range tt.checkers {
+				all = append(all, mc)
+			}
+
+			got, err := all.Check(nil)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("All.Check() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("All.Check() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

lib/checker/any.go

@@ -0,0 +1,35 @@
+package checker
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/TecharoHQ/anubis/internal"
+)
+
+type Any []Interface
+
+func (a Any) Check(r *http.Request) (bool, error) {
+	for _, c := range a {
+		match, err := c.Check(r)
+		if err != nil {
+			return match, err
+		}
+		if match {
+			return true, err // match
+		}
+	}
+
+	return false, nil // no match
+}
+
+func (a Any) Hash() string {
+	var sb strings.Builder
+
+	for _, c := range a {
+		fmt.Fprintln(&sb, c.Hash())
+	}
+
+	return internal.FastHash(sb.String())
+}

lib/checker/any_test.go

@@ -0,0 +1,83 @@
+package checker
+
+import (
+	"net/http"
+	"testing"
+)
+
+type MockChecker struct {
+	Result bool
+	Err    error
+}
+
+func (m MockChecker) Check(r *http.Request) (bool, error) {
+	return m.Result, m.Err
+}
+
+func (m MockChecker) Hash() string {
+	return "mock-hash"
+}
+
+func TestAny_Check(t *testing.T) {
+	tests := []struct {
+		name     string
+		checkers []MockChecker
+		want     bool
+		wantErr  bool
+	}{
+		{
+			name: "All match",
+			checkers: []MockChecker{
+				{Result: true, Err: nil},
+				{Result: true, Err: nil},
+			},
+			want:    true,
+			wantErr: false,
+		},
+		{
+			name: "One match",
+			checkers: []MockChecker{
+				{Result: false, Err: nil},
+				{Result: true, Err: nil},
+			},
+			want:    true,
+			wantErr: false,
+		},
+		{
+			name: "No match",
+			checkers: []MockChecker{
+				{Result: false, Err: nil},
+				{Result: false, Err: nil},
+			},
+			want:    false,
+			wantErr: false,
+		},
+		{
+			name: "Error encountered",
+			checkers: []MockChecker{
+				{Result: false, Err: nil},
+				{Result: false, Err: http.ErrNotSupported},
+			},
+			want:    false,
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var any Any
+			for _, mc := range tt.checkers {
+				any = append(any, mc)
+			}
+
+			got, err := any.Check(nil)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Any.Check() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("Any.Check() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

lib/checker/checker.go

@@ -0,0 +1,17 @@
+// Package checker defines the Checker interface and a helper utility to avoid import cycles.
+package checker
+
+import (
+	"errors"
+	"net/http"
+)
+
+var (
+	ErrUnparseableConfig = errors.New("checker: config is unparseable")
+	ErrInvalidConfig     = errors.New("checker: config is invalid")
+)
+
+type Interface interface {
+	Check(*http.Request) (matches bool, err error)
+	Hash() string
+}

lib/checker/expression/checker.go

@@ -1,43 +1,44 @@
-package policy
+package expression
 
 import (
 	"fmt"
 	"net/http"
 
 	"github.com/TecharoHQ/anubis/internal"
-	"github.com/TecharoHQ/anubis/lib/policy/config"
-	"github.com/TecharoHQ/anubis/lib/policy/expressions"
+	"github.com/TecharoHQ/anubis/lib/checker/expression/environment"
 	"github.com/google/cel-go/cel"
 	"github.com/google/cel-go/common/types"
 )
 
-type CELChecker struct {
+type Checker struct {
 	program cel.Program
 	src     string
+	hash    string
 }
 
-func NewCELChecker(cfg *config.ExpressionOrList) (*CELChecker, error) {
-	env, err := expressions.BotEnvironment()
+func New(cfg *Config) (*Checker, error) {
+	env, err := environment.Bot()
 	if err != nil {
 		return nil, err
 	}
 
-	program, err := expressions.Compile(env, cfg.String())
+	program, err := environment.Compile(env, cfg.String())
 	if err != nil {
 		return nil, fmt.Errorf("can't compile CEL program: %w", err)
 	}
 
-	return &CELChecker{
+	return &Checker{
 		src:     cfg.String(),
+		hash:    internal.FastHash(cfg.String()),
 		program: program,
 	}, nil
 }
 
-func (cc *CELChecker) Hash() string {
-	return internal.FastHash(cc.src)
+func (cc *Checker) Hash() string {
+	return cc.hash
 }
 
-func (cc *CELChecker) Check(r *http.Request) (bool, error) {
+func (cc *Checker) Check(r *http.Request) (bool, error) {
 	result, _, err := cc.program.ContextEval(r.Context(), &CELRequest{r})
 
 	if err != nil {
@@ -70,15 +71,15 @@ func (cr *CELRequest) ResolveName(name string) (any, bool) {
 	case "path":
 		return cr.URL.Path, true
 	case "query":
-		return expressions.URLValues{Values: cr.URL.Query()}, true
+		return URLValues{Values: cr.URL.Query()}, true
 	case "headers":
-		return expressions.HTTPHeaders{Header: cr.Header}, true
+		return HTTPHeaders{Header: cr.Header}, true
 	case "load_1m":
-		return expressions.Load1(), true
+		return Load1(), true
 	case "load_5m":
-		return expressions.Load5(), true
+		return Load5(), true
 	case "load_15m":
-		return expressions.Load15(), true
+		return Load15(), true
 	default:
 		return nil, false
 	}

lib/checker/expression/config.go

@@ -1,4 +1,4 @@
-package config
+package expression
 
 import (
 	"encoding/json"
@@ -9,18 +9,18 @@ import (
 )
 
 var (
-	ErrExpressionOrListMustBeStringOrObject = errors.New("config: this must be a string or an object")
-	ErrExpressionEmpty                      = errors.New("config: this expression is empty")
-	ErrExpressionCantHaveBoth               = errors.New("config: expression block can't contain multiple expression types")
+	ErrExpressionOrListMustBeStringOrObject = errors.New("expression: this must be a string or an object")
+	ErrExpressionEmpty                      = errors.New("expression: this expression is empty")
+	ErrExpressionCantHaveBoth               = errors.New("expression: expression block can't contain multiple expression types")
 )
 
-type ExpressionOrList struct {
+type Config struct {
 	Expression string   `json:"-" yaml:"-"`
 	All        []string `json:"all,omitempty" yaml:"all,omitempty"`
 	Any        []string `json:"any,omitempty" yaml:"any,omitempty"`
 }
 
-func (eol ExpressionOrList) String() string {
+func (eol Config) String() string {
 	switch {
 	case len(eol.Expression) != 0:
 		return eol.Expression
@@ -46,7 +46,7 @@ func (eol ExpressionOrList) String() string {
 	panic("this should not happen")
 }
 
-func (eol ExpressionOrList) Equal(rhs *ExpressionOrList) bool {
+func (eol Config) Equal(rhs *Config) bool {
 	if eol.Expression != rhs.Expression {
 		return false
 	}
@@ -62,7 +62,7 @@ func (eol ExpressionOrList) Equal(rhs *ExpressionOrList) bool {
 	return true
 }
 
-func (eol *ExpressionOrList) MarshalYAML() (any, error) {
+func (eol *Config) MarshalYAML() (any, error) {
 	switch {
 	case len(eol.All) == 1 && len(eol.Any) == 0:
 		eol.Expression = eol.All[0]
@@ -76,11 +76,11 @@ func (eol *ExpressionOrList) MarshalYAML() (any, error) {
 		return eol.Expression, nil
 	}
 
-	type RawExpressionOrList ExpressionOrList
+	type RawExpressionOrList Config
 	return RawExpressionOrList(*eol), nil
 }
 
-func (eol *ExpressionOrList) MarshalJSON() ([]byte, error) {
+func (eol *Config) MarshalJSON() ([]byte, error) {
 	switch {
 	case len(eol.All) == 1 && len(eol.Any) == 0:
 		eol.Expression = eol.All[0]
@@ -94,17 +94,17 @@ func (eol *ExpressionOrList) MarshalJSON() ([]byte, error) {
 		return json.Marshal(string(eol.Expression))
 	}
 
-	type RawExpressionOrList ExpressionOrList
+	type RawExpressionOrList Config
 	val := RawExpressionOrList(*eol)
 	return json.Marshal(val)
 }
 
-func (eol *ExpressionOrList) UnmarshalJSON(data []byte) error {
+func (eol *Config) UnmarshalJSON(data []byte) error {
 	switch string(data[0]) {
 	case `"`: // string
 		return json.Unmarshal(data, &eol.Expression)
 	case "{": // object
-		type RawExpressionOrList ExpressionOrList
+		type RawExpressionOrList Config
 		var val RawExpressionOrList
 		if err := json.Unmarshal(data, &val); err != nil {
 			return err
@@ -118,7 +118,7 @@ func (eol *ExpressionOrList) UnmarshalJSON(data []byte) error {
 	return ErrExpressionOrListMustBeStringOrObject
 }
 
-func (eol *ExpressionOrList) Valid() error {
+func (eol *Config) Valid() error {
 	if eol.Expression == "" && len(eol.All) == 0 && len(eol.Any) == 0 {
 		return ErrExpressionEmpty
 	}

lib/checker/expression/config_test.go

@@ -1,4 +1,4 @@
-package config
+package expression
 
 import (
 	"bytes"
@@ -12,13 +12,13 @@ import (
 func TestExpressionOrListMarshalJSON(t *testing.T) {
 	for _, tt := range []struct {
 		name   string
-		input  *ExpressionOrList
+		input  *Config
 		output []byte
 		err    error
 	}{
 		{
 			name: "single expression",
-			input: &ExpressionOrList{
+			input: &Config{
 				Expression: "true",
 			},
 			output: []byte(`"true"`),
@@ -26,7 +26,7 @@ func TestExpressionOrListMarshalJSON(t *testing.T) {
 		},
 		{
 			name: "all",
-			input: &ExpressionOrList{
+			input: &Config{
 				All: []string{"true", "true"},
 			},
 			output: []byte(`{"all":["true","true"]}`),
@@ -34,7 +34,7 @@ func TestExpressionOrListMarshalJSON(t *testing.T) {
 		},
 		{
 			name: "all one",
-			input: &ExpressionOrList{
+			input: &Config{
 				All: []string{"true"},
 			},
 			output: []byte(`"true"`),
@@ -42,7 +42,7 @@ func TestExpressionOrListMarshalJSON(t *testing.T) {
 		},
 		{
 			name: "any",
-			input: &ExpressionOrList{
+			input: &Config{
 				Any: []string{"true", "false"},
 			},
 			output: []byte(`{"any":["true","false"]}`),
@@ -50,7 +50,7 @@ func TestExpressionOrListMarshalJSON(t *testing.T) {
 		},
 		{
 			name: "any one",
-			input: &ExpressionOrList{
+			input: &Config{
 				Any: []string{"true"},
 			},
 			output: []byte(`"true"`),
@@ -75,13 +75,13 @@ func TestExpressionOrListMarshalJSON(t *testing.T) {
 func TestExpressionOrListMarshalYAML(t *testing.T) {
 	for _, tt := range []struct {
 		name   string
-		input  *ExpressionOrList
+		input  *Config
 		output []byte
 		err    error
 	}{
 		{
 			name: "single expression",
-			input: &ExpressionOrList{
+			input: &Config{
 				Expression: "true",
 			},
 			output: []byte(`"true"`),
@@ -89,7 +89,7 @@ func TestExpressionOrListMarshalYAML(t *testing.T) {
 		},
 		{
 			name: "all",
-			input: &ExpressionOrList{
+			input: &Config{
 				All: []string{"true", "true"},
 			},
 			output: []byte(`all:
@@ -99,7 +99,7 @@ func TestExpressionOrListMarshalYAML(t *testing.T) {
 		},
 		{
 			name: "all one",
-			input: &ExpressionOrList{
+			input: &Config{
 				All: []string{"true"},
 			},
 			output: []byte(`"true"`),
@@ -107,7 +107,7 @@ func TestExpressionOrListMarshalYAML(t *testing.T) {
 		},
 		{
 			name: "any",
-			input: &ExpressionOrList{
+			input: &Config{
 				Any: []string{"true", "false"},
 			},
 			output: []byte(`any:
@@ -117,7 +117,7 @@ func TestExpressionOrListMarshalYAML(t *testing.T) {
 		},
 		{
 			name: "any one",
-			input: &ExpressionOrList{
+			input: &Config{
 				Any: []string{"true"},
 			},
 			output: []byte(`"true"`),
@@ -145,14 +145,14 @@ func TestExpressionOrListUnmarshalJSON(t *testing.T) {
 	for _, tt := range []struct {
 		err      error
 		validErr error
-		result   *ExpressionOrList
+		result   *Config
 		name     string
 		inp      string
 	}{
 		{
 			name: "simple",
 			inp:  `"\"User-Agent\" in headers"`,
-			result: &ExpressionOrList{
+			result: &Config{
 				Expression: `"User-Agent" in headers`,
 			},
 		},
@@ -161,7 +161,7 @@ func TestExpressionOrListUnmarshalJSON(t *testing.T) {
 			inp: `{
 			"all": ["\"User-Agent\" in headers"]
 			}`,
-			result: &ExpressionOrList{
+			result: &Config{
 				All: []string{
 					`"User-Agent" in headers`,
 				},
@@ -172,7 +172,7 @@ func TestExpressionOrListUnmarshalJSON(t *testing.T) {
 			inp: `{
 			"any": ["\"User-Agent\" in headers"]
 			}`,
-			result: &ExpressionOrList{
+			result: &Config{
 				Any: []string{
 					`"User-Agent" in headers`,
 				},
@@ -195,7 +195,7 @@ func TestExpressionOrListUnmarshalJSON(t *testing.T) {
 		},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
-			var eol ExpressionOrList
+			var eol Config
 
 			if err := json.Unmarshal([]byte(tt.inp), &eol); !errors.Is(err, tt.err) {
 				t.Errorf("wanted unmarshal error: %v but got: %v", tt.err, err)
@@ -217,40 +217,40 @@ func TestExpressionOrListUnmarshalJSON(t *testing.T) {
 func TestExpressionOrListString(t *testing.T) {
 	for _, tt := range []struct {
 		name string
-		in   ExpressionOrList
+		in   Config
 		out  string
 	}{
 		{
 			name: "single expression",
-			in: ExpressionOrList{
+			in: Config{
 				Expression: "true",
 			},
 			out: "true",
 		},
 		{
 			name: "all",
-			in: ExpressionOrList{
+			in: Config{
 				All: []string{"true"},
 			},
 			out: "( true )",
 		},
 		{
 			name: "all with &&",
-			in: ExpressionOrList{
+			in: Config{
 				All: []string{"true", "true"},
 			},
 			out: "( true ) && ( true )",
 		},
 		{
 			name: "any",
-			in: ExpressionOrList{
+			in: Config{
 				All: []string{"true"},
 			},
 			out: "( true )",
 		},
 		{
 			name: "any with ||",
-			in: ExpressionOrList{
+			in: Config{
 				Any: []string{"true", "true"},
 			},
 			out: "( true ) || ( true )",

lib/checker/expression/environment/environment.go

@@ -1,4 +1,4 @@
-package expressions
+package environment
 
 import (
 	"math/rand/v2"
@@ -6,14 +6,15 @@ import (
 	"github.com/google/cel-go/cel"
 	"github.com/google/cel-go/common/types"
 	"github.com/google/cel-go/common/types/ref"
+	"github.com/google/cel-go/common/types/traits"
 	"github.com/google/cel-go/ext"
 )
 
-// BotEnvironment creates a new CEL environment, this is the set of
-// variables and functions that are passed into the CEL scope so that
-// Anubis can fail loudly and early when something is invalid instead
-// of blowing up at runtime.
-func BotEnvironment() (*cel.Env, error) {
+// Bot creates a new CEL environment, this is the set of variables and
+// functions that are passed into the CEL scope so that Anubis can fail
+// loudly and early when something is invalid instead of blowing up at
+// runtime.
+func Bot() (*cel.Env, error) {
 	return New(
 		// Variables exposed to CEL programs:
 		cel.Variable("remoteAddress", cel.StringType),
@@ -26,16 +27,44 @@ func BotEnvironment() (*cel.Env, error) {
 		cel.Variable("load_1m", cel.DoubleType),
 		cel.Variable("load_5m", cel.DoubleType),
 		cel.Variable("load_15m", cel.DoubleType),
+
+		// Bot-specific functions:
+		cel.Function("missingHeader",
+			cel.Overload("missingHeader_map_string_string_string",
+				[]*cel.Type{cel.MapType(cel.StringType, cel.StringType), cel.StringType},
+				cel.BoolType,
+				cel.BinaryBinding(func(headers, key ref.Val) ref.Val {
+					// Convert headers to a trait that supports Find
+					headersMap, ok := headers.(traits.Indexer)
+					if !ok {
+						return types.ValOrErr(headers, "headers is not a map, but is %T", headers)
+					}
+
+					keyStr, ok := key.(types.String)
+					if !ok {
+						return types.ValOrErr(key, "key is not a string, but is %T", key)
+					}
+
+					val := headersMap.Get(keyStr)
+					// Check if the key is missing by testing for an error
+					if types.IsError(val) {
+						return types.Bool(true) // header is missing
+					}
+					return types.Bool(false) // header is present
+				}),
+			),
+		),
 	)
 }
 
-// NewThreshold creates a new CEL environment for threshold checking.
-func ThresholdEnvironment() (*cel.Env, error) {
+// Threshold creates a new CEL environment for threshold checking.
+func Threshold() (*cel.Env, error) {
 	return New(
 		cel.Variable("weight", cel.IntType),
 	)
 }
 
+// New creates a new base CEL environment.
 func New(opts ...cel.EnvOption) (*cel.Env, error) {
 	args := []cel.EnvOption{
 		ext.Strings(
@@ -67,7 +96,7 @@ func New(opts ...cel.EnvOption) (*cel.Env, error) {
 	return cel.NewEnv(args...)
 }
 
-// Compile takes CEL environment and syntax tree then emits an optimized
+// Compile takes a CEL environment and syntax tree then emits an optimized
 // Program for execution.
 func Compile(env *cel.Env, src string) (cel.Program, error) {
 	intermediate, iss := env.Compile(src)

lib/checker/expression/environment/environment_test.go

@@ -0,0 +1,269 @@
+package environment
+
+import (
+	"testing"
+
+	"github.com/google/cel-go/common/types"
+)
+
+func TestBot(t *testing.T) {
+	env, err := Bot()
+	if err != nil {
+		t.Fatalf("failed to create bot environment: %v", err)
+	}
+
+	tests := []struct {
+		name        string
+		expression  string
+		headers     map[string]string
+		expected    types.Bool
+		description string
+	}{
+		{
+			name:       "missing-header",
+			expression: `missingHeader(headers, "Missing-Header")`,
+			headers: map[string]string{
+				"User-Agent":   "test-agent",
+				"Content-Type": "application/json",
+			},
+			expected:    types.Bool(true),
+			description: "should return true when header is missing",
+		},
+		{
+			name:       "existing-header",
+			expression: `missingHeader(headers, "User-Agent")`,
+			headers: map[string]string{
+				"User-Agent":   "test-agent",
+				"Content-Type": "application/json",
+			},
+			expected:    types.Bool(false),
+			description: "should return false when header exists",
+		},
+		{
+			name:       "case-sensitive",
+			expression: `missingHeader(headers, "user-agent")`,
+			headers: map[string]string{
+				"User-Agent": "test-agent",
+			},
+			expected:    types.Bool(true),
+			description: "should be case-sensitive (user-agent != User-Agent)",
+		},
+		{
+			name:        "empty-headers",
+			expression:  `missingHeader(headers, "Any-Header")`,
+			headers:     map[string]string{},
+			expected:    types.Bool(true),
+			description: "should return true for any header when map is empty",
+		},
+		{
+			name:       "real-world-sec-ch-ua",
+			expression: `missingHeader(headers, "Sec-Ch-Ua")`,
+			headers: map[string]string{
+				"User-Agent": "curl/7.68.0",
+				"Accept":     "*/*",
+				"Host":       "example.com",
+			},
+			expected:    types.Bool(true),
+			description: "should detect missing browser-specific headers from bots",
+		},
+		{
+			name:       "browser-with-sec-ch-ua",
+			expression: `missingHeader(headers, "Sec-Ch-Ua")`,
+			headers: map[string]string{
+				"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
+				"Sec-Ch-Ua":  `"Chrome"; v="91", "Not A Brand"; v="99"`,
+				"Accept":     "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
+			},
+			expected:    types.Bool(false),
+			description: "should return false when browser sends Sec-Ch-Ua header",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			prog, err := Compile(env, tt.expression)
+			if err != nil {
+				t.Fatalf("failed to compile expression %q: %v", tt.expression, err)
+			}
+
+			result, _, err := prog.Eval(map[string]interface{}{
+				"headers": tt.headers,
+			})
+			if err != nil {
+				t.Fatalf("failed to evaluate expression %q: %v", tt.expression, err)
+			}
+
+			if result != tt.expected {
+				t.Errorf("%s: expected %v, got %v", tt.description, tt.expected, result)
+			}
+		})
+	}
+
+	t.Run("function-compilation", func(t *testing.T) {
+		src := `missingHeader(headers, "Test-Header")`
+		_, err := Compile(env, src)
+		if err != nil {
+			t.Fatalf("failed to compile missingHeader expression: %v", err)
+		}
+	})
+}
+
+func TestThreshold(t *testing.T) {
+	env, err := Threshold()
+	if err != nil {
+		t.Fatalf("failed to create threshold environment: %v", err)
+	}
+
+	tests := []struct {
+		name          string
+		expression    string
+		variables     map[string]interface{}
+		expected      types.Bool
+		description   string
+		shouldCompile bool
+	}{
+		{
+			name:          "weight-variable-available",
+			expression:    `weight > 100`,
+			variables:     map[string]interface{}{"weight": 150},
+			expected:      types.Bool(true),
+			description:   "should support weight variable in expressions",
+			shouldCompile: true,
+		},
+		{
+			name:          "weight-variable-false-case",
+			expression:    `weight > 100`,
+			variables:     map[string]interface{}{"weight": 50},
+			expected:      types.Bool(false),
+			description:   "should correctly evaluate weight comparisons",
+			shouldCompile: true,
+		},
+		{
+			name:          "missingHeader-not-available",
+			expression:    `missingHeader(headers, "Test")`,
+			variables:     map[string]interface{}{},
+			expected:      types.Bool(false), // not used
+			description:   "should not have missingHeader function available",
+			shouldCompile: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			prog, err := Compile(env, tt.expression)
+
+			if !tt.shouldCompile {
+				if err == nil {
+					t.Fatalf("%s: expected compilation to fail but it succeeded", tt.description)
+				}
+				return // Test passed - compilation failed as expected
+			}
+
+			if err != nil {
+				t.Fatalf("failed to compile expression %q: %v", tt.expression, err)
+			}
+
+			result, _, err := prog.Eval(tt.variables)
+			if err != nil {
+				t.Fatalf("failed to evaluate expression %q: %v", tt.expression, err)
+			}
+
+			if result != tt.expected {
+				t.Errorf("%s: expected %v, got %v", tt.description, tt.expected, result)
+			}
+		})
+	}
+}
+
+func TestNewEnvironment(t *testing.T) {
+	env, err := New()
+	if err != nil {
+		t.Fatalf("failed to create new environment: %v", err)
+	}
+
+	tests := []struct {
+		name          string
+		expression    string
+		variables     map[string]interface{}
+		expectBool    *bool // nil if we just want to test compilation or non-bool result
+		description   string
+		shouldCompile bool
+	}{
+		{
+			name:          "randInt-function-compilation",
+			expression:    `randInt(10)`,
+			variables:     map[string]interface{}{},
+			expectBool:    nil, // Don't check result, just compilation
+			description:   "should compile randInt function",
+			shouldCompile: true,
+		},
+		{
+			name:          "randInt-range-validation",
+			expression:    `randInt(10) >= 0 && randInt(10) < 10`,
+			variables:     map[string]interface{}{},
+			expectBool:    boolPtr(true),
+			description:   "should return values in correct range",
+			shouldCompile: true,
+		},
+		{
+			name:          "strings-extension-size",
+			expression:    `"hello".size() == 5`,
+			variables:     map[string]interface{}{},
+			expectBool:    boolPtr(true),
+			description:   "should support string extension functions",
+			shouldCompile: true,
+		},
+		{
+			name:          "strings-extension-contains",
+			expression:    `"hello world".contains("world")`,
+			variables:     map[string]interface{}{},
+			expectBool:    boolPtr(true),
+			description:   "should support string contains function",
+			shouldCompile: true,
+		},
+		{
+			name:          "strings-extension-startsWith",
+			expression:    `"hello world".startsWith("hello")`,
+			variables:     map[string]interface{}{},
+			expectBool:    boolPtr(true),
+			description:   "should support string startsWith function",
+			shouldCompile: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			prog, err := Compile(env, tt.expression)
+
+			if !tt.shouldCompile {
+				if err == nil {
+					t.Fatalf("%s: expected compilation to fail but it succeeded", tt.description)
+				}
+				return // Test passed - compilation failed as expected
+			}
+
+			if err != nil {
+				t.Fatalf("failed to compile expression %q: %v", tt.expression, err)
+			}
+
+			// If we only want to test compilation, skip evaluation
+			if tt.expectBool == nil {
+				return
+			}
+
+			result, _, err := prog.Eval(tt.variables)
+			if err != nil {
+				t.Fatalf("failed to evaluate expression %q: %v", tt.expression, err)
+			}
+
+			if result != types.Bool(*tt.expectBool) {
+				t.Errorf("%s: expected %v, got %v", tt.description, *tt.expectBool, result)
+			}
+		})
+	}
+}
+
+// Helper function to create bool pointers
+func boolPtr(b bool) *bool {
+	return &b
+}

lib/checker/expression/factory.go

@@ -0,0 +1,43 @@
+package expression
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+
+	"github.com/TecharoHQ/anubis/lib/checker"
+)
+
+func init() {
+	checker.Register("expression", Factory{})
+}
+
+type Factory struct{}
+
+func (f Factory) Build(ctx context.Context, data json.RawMessage) (checker.Interface, error) {
+	var fc = &Config{}
+
+	if err := json.Unmarshal([]byte(data), fc); err != nil {
+		return nil, errors.Join(checker.ErrUnparseableConfig, err)
+	}
+
+	if err := fc.Valid(); err != nil {
+		return nil, errors.Join(checker.ErrInvalidConfig, err)
+	}
+
+	return New(fc)
+}
+
+func (f Factory) Valid(ctx context.Context, data json.RawMessage) error {
+	var fc = &Config{}
+
+	if err := json.Unmarshal([]byte(data), fc); err != nil {
+		return err
+	}
+
+	if err := fc.Valid(); err != nil {
+		return err
+	}
+
+	return nil
+}

lib/checker/expression/http_headers.go

@@ -1,4 +1,4 @@
-package expressions
+package expression
 
 import (
 	"net/http"

lib/checker/expression/http_headers_test.go

@@ -1,4 +1,4 @@
-package expressions
+package expression
 
 import (
 	"net/http"

lib/checker/expression/loadavg.go

@@ -1,4 +1,4 @@
-package expressions
+package expression
 
 import (
 	"context"

lib/checker/expression/url_values.go

@@ -1,4 +1,4 @@
-package expressions
+package expression
 
 import (
 	"errors"

lib/checker/expression/url_values_test.go

@@ -1,4 +1,4 @@
-package expressions
+package expression
 
 import (
 	"net/url"

lib/checker/headerexists/checker.go

@@ -0,0 +1,32 @@
+package headerexists
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/TecharoHQ/anubis/internal"
+	"github.com/TecharoHQ/anubis/lib/checker"
+)
+
+func New(key string) checker.Interface {
+	return headerExistsChecker{
+		header: strings.TrimSpace(http.CanonicalHeaderKey(key)),
+		hash:   internal.FastHash(key),
+	}
+}
+
+type headerExistsChecker struct {
+	header, hash string
+}
+
+func (hec headerExistsChecker) Check(r *http.Request) (bool, error) {
+	if r.Header.Get(hec.header) != "" {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+func (hec headerExistsChecker) Hash() string {
+	return hec.hash
+}

lib/checker/headerexists/checker_test.go

@@ -0,0 +1,57 @@
+package headerexists
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"testing"
+)
+
+func TestChecker(t *testing.T) {
+	fac := Factory{}
+
+	for _, tt := range []struct {
+		name      string
+		header    string
+		reqHeader string
+		ok        bool
+	}{
+		{
+			name:      "match",
+			header:    "Authorization",
+			reqHeader: "Authorization",
+			ok:        true,
+		},
+		{
+			name:      "not_match",
+			header:    "Authorization",
+			reqHeader: "Authentication",
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			hec, err := fac.Build(t.Context(), json.RawMessage(fmt.Sprintf("%q", tt.header)))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			t.Log(hec.Hash())
+
+			r, err := http.NewRequest(http.MethodGet, "/", nil)
+			if err != nil {
+				t.Fatalf("can't make request: %v", err)
+			}
+
+			r.Header.Set(tt.reqHeader, "hunter2")
+
+			ok, err := hec.Check(r)
+
+			if tt.ok != ok {
+				t.Errorf("ok: %v, wanted: %v", ok, tt.ok)
+			}
+
+			if err != nil {
+				t.Errorf("err: %v", err)
+			}
+		})
+	}
+}

lib/checker/headerexists/factory.go

@@ -0,0 +1,40 @@
+package headerexists
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/TecharoHQ/anubis/lib/checker"
+)
+
+type Factory struct{}
+
+func (f Factory) Build(ctx context.Context, data json.RawMessage) (checker.Interface, error) {
+	var headerName string
+
+	if err := json.Unmarshal([]byte(data), &headerName); err != nil {
+		return nil, fmt.Errorf("%w: want string", checker.ErrUnparseableConfig)
+	}
+
+	if err := f.Valid(ctx, data); err != nil {
+		return nil, err
+	}
+
+	return New(http.CanonicalHeaderKey(headerName)), nil
+}
+
+func (Factory) Valid(ctx context.Context, data json.RawMessage) error {
+	var headerName string
+
+	if err := json.Unmarshal([]byte(data), &headerName); err != nil {
+		return fmt.Errorf("%w: want string", checker.ErrUnparseableConfig)
+	}
+
+	if headerName == "" {
+		return fmt.Errorf("%w: string must not be empty", checker.ErrInvalidConfig)
+	}
+
+	return nil
+}

lib/checker/headerexists/factory_test.go

@@ -0,0 +1,60 @@
+package headerexists
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestFactoryGood(t *testing.T) {
+	files, err := os.ReadDir("./testdata/good")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fac := Factory{}
+
+	for _, fname := range files {
+		t.Run(fname.Name(), func(t *testing.T) {
+			data, err := os.ReadFile(filepath.Join("testdata", "good", fname.Name()))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if err := fac.Valid(t.Context(), json.RawMessage(data)); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+func TestFactoryBad(t *testing.T) {
+	files, err := os.ReadDir("./testdata/bad")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fac := Factory{}
+
+	for _, fname := range files {
+		t.Run(fname.Name(), func(t *testing.T) {
+			data, err := os.ReadFile(filepath.Join("testdata", "bad", fname.Name()))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			t.Run("Build", func(t *testing.T) {
+				if _, err := fac.Build(t.Context(), json.RawMessage(data)); err == nil {
+					t.Fatal(err)
+				}
+			})
+
+			t.Run("Valid", func(t *testing.T) {
+				if err := fac.Valid(t.Context(), json.RawMessage(data)); err == nil {
+					t.Fatal(err)
+				}
+			})
+		})
+	}
+}

lib/checker/headerexists/testdata/bad/empty.json

@@ -0,0 +1 @@
+""

lib/checker/headerexists/testdata/bad/object.json

@@ -0,0 +1 @@
+{}

lib/checker/headerexists/testdata/good/authorization.json

@@ -0,0 +1 @@
+"Authorization"

lib/checker/headermatches/checker.go

@@ -0,0 +1,46 @@
+package headermatches
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"regexp"
+
+	"github.com/TecharoHQ/anubis/lib/checker"
+)
+
+type Checker struct {
+	header string
+	regexp *regexp.Regexp
+	hash   string
+}
+
+func (c *Checker) Check(r *http.Request) (bool, error) {
+	if c.regexp.MatchString(r.Header.Get(c.header)) {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+func (c *Checker) Hash() string {
+	return c.hash
+}
+
+func New(key, valueRex string) (checker.Interface, error) {
+	fc := fileConfig{
+		Header:     key,
+		ValueRegex: valueRex,
+	}
+
+	if err := fc.Valid(); err != nil {
+		return nil, err
+	}
+
+	data, err := json.Marshal(fc)
+	if err != nil {
+		return nil, err
+	}
+
+	return Factory{}.Build(context.Background(), json.RawMessage(data))
+}

lib/checker/headermatches/checker_test.go

@@ -0,0 +1,98 @@
+package headermatches
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"testing"
+)
+
+func TestChecker(t *testing.T) {
+
+}
+
+func TestHeaderMatchesChecker(t *testing.T) {
+	fac := Factory{}
+
+	for _, tt := range []struct {
+		err            error
+		name           string
+		header         string
+		rexStr         string
+		reqHeaderKey   string
+		reqHeaderValue string
+		ok             bool
+	}{
+		{
+			name:           "match",
+			header:         "Cf-Worker",
+			rexStr:         ".*",
+			reqHeaderKey:   "Cf-Worker",
+			reqHeaderValue: "true",
+			ok:             true,
+			err:            nil,
+		},
+		{
+			name:           "not_match",
+			header:         "Cf-Worker",
+			rexStr:         "false",
+			reqHeaderKey:   "Cf-Worker",
+			reqHeaderValue: "true",
+			ok:             false,
+			err:            nil,
+		},
+		{
+			name:           "not_present",
+			header:         "Cf-Worker",
+			rexStr:         "foobar",
+			reqHeaderKey:   "Something-Else",
+			reqHeaderValue: "true",
+			ok:             false,
+			err:            nil,
+		},
+		{
+			name:   "invalid_regex",
+			rexStr: "a(b",
+			err:    ErrInvalidRegex,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			fc := fileConfig{
+				Header:     tt.header,
+				ValueRegex: tt.rexStr,
+			}
+			data, err := json.Marshal(fc)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			hmc, err := fac.Build(t.Context(), json.RawMessage(data))
+			if err != nil && !errors.Is(err, tt.err) {
+				t.Fatalf("creating HeaderMatchesChecker failed")
+			}
+
+			if tt.err != nil && hmc == nil {
+				return
+			}
+
+			t.Log(hmc.Hash())
+
+			r, err := http.NewRequest(http.MethodGet, "/", nil)
+			if err != nil {
+				t.Fatalf("can't make request: %v", err)
+			}
+
+			r.Header.Set(tt.reqHeaderKey, tt.reqHeaderValue)
+
+			ok, err := hmc.Check(r)
+
+			if tt.ok != ok {
+				t.Errorf("ok: %v, wanted: %v", ok, tt.ok)
+			}
+
+			if err != nil && tt.err != nil && !errors.Is(err, tt.err) {
+				t.Errorf("err: %v, wanted: %v", err, tt.err)
+			}
+		})
+	}
+}

lib/checker/headermatches/config.go

@@ -0,0 +1,44 @@
+package headermatches
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+)
+
+var (
+	ErrNoHeader     = errors.New("headermatches: no header is configured")
+	ErrNoValueRegex = errors.New("headermatches: no value regex is configured")
+	ErrInvalidRegex = errors.New("headermatches: value regex is invalid")
+)
+
+type fileConfig struct {
+	Header     string `json:"header" yaml:"header"`
+	ValueRegex string `json:"value_regex" yaml:"value_regex"`
+}
+
+func (fc fileConfig) String() string {
+	return fmt.Sprintf("header=%q value_regex=%q", fc.Header, fc.ValueRegex)
+}
+
+func (fc fileConfig) Valid() error {
+	var errs []error
+
+	if fc.Header == "" {
+		errs = append(errs, ErrNoHeader)
+	}
+
+	if fc.ValueRegex == "" {
+		errs = append(errs, ErrNoValueRegex)
+	}
+
+	if _, err := regexp.Compile(fc.ValueRegex); err != nil {
+		errs = append(errs, ErrInvalidRegex, err)
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(errs...)
+	}
+
+	return nil
+}

lib/checker/headermatches/config_test.go

@@ -0,0 +1,55 @@
+package headermatches
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestFileConfigValid(t *testing.T) {
+	for _, tt := range []struct {
+		name, description string
+		in                fileConfig
+		err               error
+	}{
+		{
+			name:        "simple happy",
+			description: "the most common usecase",
+			in: fileConfig{
+				Header:     "User-Agent",
+				ValueRegex: ".*",
+			},
+		},
+		{
+			name:        "no header",
+			description: "Header must be set, it is not",
+			in: fileConfig{
+				ValueRegex: ".*",
+			},
+			err: ErrNoHeader,
+		},
+		{
+			name:        "no value regex",
+			description: "ValueRegex must be set, it is not",
+			in: fileConfig{
+				Header: "User-Agent",
+			},
+			err: ErrNoValueRegex,
+		},
+		{
+			name:        "invalid regex",
+			description: "the user wrote an invalid value regular expression",
+			in: fileConfig{
+				Header:     "User-Agent",
+				ValueRegex: "[a-z",
+			},
+			err: ErrInvalidRegex,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := tt.in.Valid(); !errors.Is(err, tt.err) {
+				t.Log(tt.description)
+				t.Fatal(err)
+			}
+		})
+	}
+}

lib/checker/headermatches/factory.go

@@ -0,0 +1,66 @@
+package headermatches
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"regexp"
+
+	"github.com/TecharoHQ/anubis/internal"
+	"github.com/TecharoHQ/anubis/lib/checker"
+)
+
+func init() {
+	checker.Register("header_matches", Factory{})
+	checker.Register("user_agent", Factory{defaultHeader: "User-Agent"})
+}
+
+type Factory struct {
+	defaultHeader string
+}
+
+func (f Factory) Build(ctx context.Context, data json.RawMessage) (checker.Interface, error) {
+	var fc fileConfig
+
+	if f.defaultHeader != "" {
+		fc.Header = f.defaultHeader
+	}
+
+	if err := json.Unmarshal([]byte(data), &fc); err != nil {
+		return nil, errors.Join(checker.ErrUnparseableConfig, err)
+	}
+
+	if err := fc.Valid(); err != nil {
+		return nil, errors.Join(checker.ErrInvalidConfig, err)
+	}
+
+	valueRex, err := regexp.Compile(fc.ValueRegex)
+	if err != nil {
+		return nil, errors.Join(ErrInvalidRegex, err)
+	}
+
+	return &Checker{
+		header: http.CanonicalHeaderKey(fc.Header),
+		regexp: valueRex,
+		hash:   internal.FastHash(fc.String()),
+	}, nil
+}
+
+func (f Factory) Valid(ctx context.Context, data json.RawMessage) error {
+	var fc fileConfig
+
+	if f.defaultHeader != "" {
+		fc.Header = f.defaultHeader
+	}
+
+	if err := json.Unmarshal([]byte(data), &fc); err != nil {
+		return err
+	}
+
+	if err := fc.Valid(); err != nil {
+		return err
+	}
+
+	return nil
+}

lib/checker/headermatches/factory_test.go

@@ -0,0 +1,52 @@
+package headermatches
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestFactoryGood(t *testing.T) {
+	files, err := os.ReadDir("./testdata/good")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fac := Factory{}
+
+	for _, fname := range files {
+		t.Run(fname.Name(), func(t *testing.T) {
+			data, err := os.ReadFile(filepath.Join("testdata", "good", fname.Name()))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if err := fac.Valid(t.Context(), json.RawMessage(data)); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+func TestFactoryBad(t *testing.T) {
+	files, err := os.ReadDir("./testdata/bad")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fac := Factory{}
+
+	for _, fname := range files {
+		t.Run(fname.Name(), func(t *testing.T) {
+			data, err := os.ReadFile(filepath.Join("testdata", "bad", fname.Name()))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if err := fac.Valid(t.Context(), json.RawMessage(data)); err == nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}

lib/checker/headermatches/testdata/bad/invalid_config.json

@@ -0,0 +1 @@
+}

lib/checker/headermatches/testdata/bad/invalid_value_regex.json

@@ -0,0 +1,4 @@
+{
+  "header": "User-Agent",
+  "value_regex": "a(b"
+}

lib/checker/headermatches/testdata/bad/no_header.json

@@ -0,0 +1,3 @@
+{
+  "value_regex": "PaleMoon"
+}

lib/checker/headermatches/testdata/bad/no_value_regex.json

@@ -0,0 +1,3 @@
+{
+  "header": "User-Agent"
+}

lib/checker/headermatches/testdata/bad/nothing.json

@@ -0,0 +1 @@
+{}

lib/checker/headermatches/testdata/good/simple.json

@@ -0,0 +1,4 @@
+{
+  "header": "User-Agent",
+  "value_regex": "PaleMoon"
+}

lib/checker/headermatches/useragent.go

@@ -0,0 +1,35 @@
+package headermatches
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/TecharoHQ/anubis/lib/checker"
+)
+
+func ValidUserAgent(valueRex string) error {
+	fc := fileConfig{
+		Header:     "User-Agent",
+		ValueRegex: valueRex,
+	}
+
+	return fc.Valid()
+}
+
+func NewUserAgent(valueRex string) (checker.Interface, error) {
+	fc := fileConfig{
+		Header:     "User-Agent",
+		ValueRegex: valueRex,
+	}
+
+	if err := fc.Valid(); err != nil {
+		return nil, err
+	}
+
+	data, err := json.Marshal(fc)
+	if err != nil {
+		return nil, err
+	}
+
+	return Factory{}.Build(context.Background(), json.RawMessage(data))
+}

lib/checker/path/checker.go

@@ -0,0 +1,37 @@
+package path
+
+import (
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+
+	"github.com/TecharoHQ/anubis"
+	"github.com/TecharoHQ/anubis/internal"
+	"github.com/TecharoHQ/anubis/lib/checker"
+)
+
+func New(rexStr string) (checker.Interface, error) {
+	rex, err := regexp.Compile(strings.TrimSpace(rexStr))
+	if err != nil {
+		return nil, fmt.Errorf("%w: regex %s failed parse: %w", anubis.ErrMisconfiguration, rexStr, err)
+	}
+	return &Checker{rex, internal.FastHash(rexStr)}, nil
+}
+
+type Checker struct {
+	regexp *regexp.Regexp
+	hash   string
+}
+
+func (c *Checker) Check(r *http.Request) (bool, error) {
+	if c.regexp.MatchString(r.URL.Path) {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+func (c *Checker) Hash() string {
+	return c.hash
+}

lib/checker/path/checker_test.go

@@ -0,0 +1,90 @@
+package path
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"testing"
+)
+
+func TestChecker(t *testing.T) {
+	fac := Factory{}
+
+	for _, tt := range []struct {
+		err     error
+		name    string
+		rexStr  string
+		reqPath string
+		ok      bool
+	}{
+		{
+			name:    "match",
+			rexStr:  "^/api/.*",
+			reqPath: "/api/v1/users",
+			ok:      true,
+			err:     nil,
+		},
+		{
+			name:    "not_match",
+			rexStr:  "^/api/.*",
+			reqPath: "/static/index.html",
+			ok:      false,
+			err:     nil,
+		},
+		{
+			name:    "wildcard_match",
+			rexStr:  ".*\\.json$",
+			reqPath: "/data/config.json",
+			ok:      true,
+			err:     nil,
+		},
+		{
+			name:    "wildcard_not_match",
+			rexStr:  ".*\\.json$",
+			reqPath: "/data/config.yaml",
+			ok:      false,
+			err:     nil,
+		},
+		{
+			name:   "invalid_regex",
+			rexStr: "a(b",
+			err:    ErrInvalidRegex,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			fc := fileConfig{
+				Regex: tt.rexStr,
+			}
+			data, err := json.Marshal(fc)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			pc, err := fac.Build(t.Context(), json.RawMessage(data))
+			if err != nil && !errors.Is(err, tt.err) {
+				t.Fatalf("creating PathChecker failed")
+			}
+
+			if tt.err != nil && pc == nil {
+				return
+			}
+
+			t.Log(pc.Hash())
+
+			r, err := http.NewRequest(http.MethodGet, tt.reqPath, nil)
+			if err != nil {
+				t.Fatalf("can't make request: %v", err)
+			}
+
+			ok, err := pc.Check(r)
+
+			if tt.ok != ok {
+				t.Errorf("ok: %v, wanted: %v", ok, tt.ok)
+			}
+
+			if err != nil && tt.err != nil && !errors.Is(err, tt.err) {
+				t.Errorf("err: %v, wanted: %v", err, tt.err)
+			}
+		})
+	}
+}

lib/checker/path/config.go

@@ -0,0 +1,38 @@
+package path
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+)
+
+var (
+	ErrNoRegex      = errors.New("path: no regex is configured")
+	ErrInvalidRegex = errors.New("path: regex is invalid")
+)
+
+type fileConfig struct {
+	Regex string `json:"regex" yaml:"regex"`
+}
+
+func (fc fileConfig) String() string {
+	return fmt.Sprintf("regex=%q", fc.Regex)
+}
+
+func (fc fileConfig) Valid() error {
+	var errs []error
+
+	if fc.Regex == "" {
+		errs = append(errs, ErrNoRegex)
+	}
+
+	if _, err := regexp.Compile(fc.Regex); err != nil {
+		errs = append(errs, ErrInvalidRegex, err)
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(errs...)
+	}
+
+	return nil
+}

lib/checker/path/config_test.go

@@ -0,0 +1,50 @@
+package path
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestFileConfigValid(t *testing.T) {
+	for _, tt := range []struct {
+		name, description string
+		in                fileConfig
+		err               error
+	}{
+		{
+			name:        "simple happy",
+			description: "the most common usecase",
+			in: fileConfig{
+				Regex: "^/api/.*",
+			},
+		},
+		{
+			name:        "wildcard match",
+			description: "match files with specific extension",
+			in: fileConfig{
+				Regex: ".*[.]json$",
+			},
+		},
+		{
+			name:        "no regex",
+			description: "Regex must be set, it is not",
+			in:          fileConfig{},
+			err:         ErrNoRegex,
+		},
+		{
+			name:        "invalid regex",
+			description: "the user wrote an invalid regular expression",
+			in: fileConfig{
+				Regex: "[a-z",
+			},
+			err: ErrInvalidRegex,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := tt.in.Valid(); !errors.Is(err, tt.err) {
+				t.Log(tt.description)
+				t.Fatalf("got %v, wanted %v", err, tt.err)
+			}
+		})
+	}
+}

lib/checker/path/factory.go

@@ -0,0 +1,58 @@
+package path
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"regexp"
+	"strings"
+
+	"github.com/TecharoHQ/anubis/internal"
+	"github.com/TecharoHQ/anubis/lib/checker"
+)
+
+func init() {
+	checker.Register("path", Factory{})
+}
+
+type Factory struct{}
+
+func (f Factory) Build(ctx context.Context, data json.RawMessage) (checker.Interface, error) {
+	var fc fileConfig
+
+	if err := json.Unmarshal([]byte(data), &fc); err != nil {
+		return nil, errors.Join(checker.ErrUnparseableConfig, err)
+	}
+
+	if err := fc.Valid(); err != nil {
+		return nil, errors.Join(checker.ErrInvalidConfig, err)
+	}
+
+	pathRex, err := regexp.Compile(strings.TrimSpace(fc.Regex))
+	if err != nil {
+		return nil, errors.Join(ErrInvalidRegex, err)
+	}
+
+	return &Checker{
+		regexp: pathRex,
+		hash:   internal.FastHash(fc.String()),
+	}, nil
+}
+
+func (f Factory) Valid(ctx context.Context, data json.RawMessage) error {
+	var fc fileConfig
+
+	if err := json.Unmarshal([]byte(data), &fc); err != nil {
+		return errors.Join(checker.ErrUnparseableConfig, err)
+	}
+
+	return fc.Valid()
+}
+
+func Valid(pathRex string) error {
+	fc := fileConfig{
+		Regex: pathRex,
+	}
+
+	return fc.Valid()
+}

lib/checker/path/factory_test.go

@@ -0,0 +1,52 @@
+package path
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestFactoryGood(t *testing.T) {
+	files, err := os.ReadDir("./testdata/good")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fac := Factory{}
+
+	for _, fname := range files {
+		t.Run(fname.Name(), func(t *testing.T) {
+			data, err := os.ReadFile(filepath.Join("testdata", "good", fname.Name()))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if err := fac.Valid(t.Context(), json.RawMessage(data)); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+func TestFactoryBad(t *testing.T) {
+	files, err := os.ReadDir("./testdata/bad")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fac := Factory{}
+
+	for _, fname := range files {
+		t.Run(fname.Name(), func(t *testing.T) {
+			data, err := os.ReadFile(filepath.Join("testdata", "bad", fname.Name()))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if err := fac.Valid(t.Context(), json.RawMessage(data)); err == nil {
+				t.Fatal("expected validation to fail")
+			}
+		})
+	}
+}

lib/checker/path/testdata/bad/invalid_regex.json

@@ -0,0 +1,3 @@
+{
+  "regex": "a(b"
+}

lib/checker/path/testdata/bad/nothing.json

@@ -0,0 +1 @@
+{}

lib/checker/path/testdata/good/simple.json

@@ -0,0 +1,3 @@
+{
+  "regex": "^/api/.*"
+}

lib/checker/path/testdata/good/wildcard.json

@@ -0,0 +1,3 @@
+{
+  "regex": ".*\\.json$"
+}

lib/checker/registry.go

@@ -0,0 +1,43 @@
+package checker
+
+import (
+	"context"
+	"encoding/json"
+	"sort"
+	"sync"
+)
+
+type Factory interface {
+	Build(context.Context, json.RawMessage) (Interface, error)
+	Valid(context.Context, json.RawMessage) error
+}
+
+var (
+	registry map[string]Factory = map[string]Factory{}
+	regLock  sync.RWMutex
+)
+
+func Register(name string, factory Factory) {
+	regLock.Lock()
+	defer regLock.Unlock()
+
+	registry[name] = factory
+}
+
+func Get(name string) (Factory, bool) {
+	regLock.RLock()
+	defer regLock.RUnlock()
+	result, ok := registry[name]
+	return result, ok
+}
+
+func Methods() []string {
+	regLock.RLock()
+	defer regLock.RUnlock()
+	var result []string
+	for method := range registry {
+		result = append(result, method)
+	}
+	sort.Strings(result)
+	return result
+}

lib/checker/remoteaddress/remoteaddress.go

@@ -0,0 +1,127 @@
+package remoteaddress
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/netip"
+
+	"github.com/TecharoHQ/anubis"
+	"github.com/TecharoHQ/anubis/internal"
+	"github.com/TecharoHQ/anubis/lib/checker"
+	"github.com/gaissmai/bart"
+)
+
+var (
+	ErrNoRemoteAddresses = errors.New("remoteaddress: no remote addresses defined")
+	ErrInvalidCIDR       = errors.New("remoteaddress: invalid CIDR")
+)
+
+func init() {
+	checker.Register("remote_address", Factory{})
+}
+
+type Factory struct{}
+
+func (Factory) Valid(_ context.Context, inp json.RawMessage) error {
+	var fc fileConfig
+	if err := json.Unmarshal([]byte(inp), &fc); err != nil {
+		return fmt.Errorf("%w: %w", checker.ErrUnparseableConfig, err)
+	}
+
+	if err := fc.Valid(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (Factory) Build(_ context.Context, inp json.RawMessage) (checker.Interface, error) {
+	c := struct {
+		RemoteAddr []netip.Prefix `json:"remote_addresses,omitempty" yaml:"remote_addresses,omitempty"`
+	}{}
+
+	if err := json.Unmarshal([]byte(inp), &c); err != nil {
+		return nil, fmt.Errorf("%w: %w", checker.ErrUnparseableConfig, err)
+	}
+
+	table := new(bart.Lite)
+
+	for _, cidr := range c.RemoteAddr {
+		table.Insert(cidr)
+	}
+
+	return &RemoteAddrChecker{
+		prefixTable: table,
+		hash:        internal.FastHash(string(inp)),
+	}, nil
+}
+
+type fileConfig struct {
+	RemoteAddr []string `json:"remote_addresses,omitempty" yaml:"remote_addresses,omitempty"`
+}
+
+func (fc fileConfig) Valid() error {
+	var errs []error
+
+	if len(fc.RemoteAddr) == 0 {
+		errs = append(errs, ErrNoRemoteAddresses)
+	}
+
+	for _, cidr := range fc.RemoteAddr {
+		if _, err := netip.ParsePrefix(cidr); err != nil {
+			errs = append(errs, fmt.Errorf("%w: cidr %q is invalid: %w", ErrInvalidCIDR, cidr, err))
+		}
+	}
+
+	if len(errs) != 0 {
+		return fmt.Errorf("%w: %w", checker.ErrInvalidConfig, errors.Join(errs...))
+	}
+
+	return nil
+}
+
+func Valid(cidrs []string) error {
+	fc := fileConfig{
+		RemoteAddr: cidrs,
+	}
+
+	return fc.Valid()
+}
+
+func New(cidrs []string) (checker.Interface, error) {
+	fc := fileConfig{
+		RemoteAddr: cidrs,
+	}
+	data, err := json.Marshal(fc)
+	if err != nil {
+		return nil, err
+	}
+
+	return Factory{}.Build(context.Background(), json.RawMessage(data))
+}
+
+type RemoteAddrChecker struct {
+	prefixTable *bart.Lite
+	hash        string
+}
+
+func (rac *RemoteAddrChecker) Check(r *http.Request) (bool, error) {
+	host := r.Header.Get("X-Real-Ip")
+	if host == "" {
+		return false, fmt.Errorf("%w: header X-Real-Ip is not set", anubis.ErrMisconfiguration)
+	}
+
+	addr, err := netip.ParseAddr(host)
+	if err != nil {
+		return false, fmt.Errorf("%w: %s is not an IP address: %w", anubis.ErrMisconfiguration, host, err)
+	}
+
+	return rac.prefixTable.Contains(addr), nil
+}
+
+func (rac *RemoteAddrChecker) Hash() string {
+	return rac.hash
+}

lib/checker/remoteaddress/remoteaddress_test.go

@@ -0,0 +1,138 @@
+package remoteaddress_test
+
+import (
+	_ "embed"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"testing"
+
+	"github.com/TecharoHQ/anubis/lib/checker"
+	"github.com/TecharoHQ/anubis/lib/checker/remoteaddress"
+)
+
+func TestFactoryIsCheckerFactory(t *testing.T) {
+	if _, ok := (any(remoteaddress.Factory{})).(checker.Factory); !ok {
+		t.Fatal("Factory is not an instance of checker.Factory")
+	}
+}
+
+func TestFactoryValidateConfig(t *testing.T) {
+	f := remoteaddress.Factory{}
+
+	for _, tt := range []struct {
+		name string
+		data []byte
+		err  error
+	}{
+		{
+			name: "basic valid",
+			data: []byte(`{
+  "remote_addresses": [
+    "1.1.1.1/32"
+  ]
+}`),
+		},
+		{
+			name: "not json",
+			data: []byte(`]`),
+			err:  checker.ErrUnparseableConfig,
+		},
+		{
+			name: "no cidr",
+			data: []byte(`{
+  "remote_addresses": []
+}`),
+			err: remoteaddress.ErrNoRemoteAddresses,
+		},
+		{
+			name: "bad cidr",
+			data: []byte(`{
+  "remote_addresses": [
+    "according to all laws of aviation"
+  ]
+}`),
+			err: remoteaddress.ErrInvalidCIDR,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			data := json.RawMessage(tt.data)
+
+			if err := f.Valid(t.Context(), data); !errors.Is(err, tt.err) {
+				t.Logf("want: %v", tt.err)
+				t.Logf("got:  %v", err)
+				t.Fatal("validation didn't do what was expected")
+			}
+		})
+	}
+}
+
+func TestFactoryCreate(t *testing.T) {
+	f := remoteaddress.Factory{}
+
+	for _, tt := range []struct {
+		name  string
+		data  []byte
+		err   error
+		ip    string
+		match bool
+	}{
+		{
+			name: "basic valid",
+			data: []byte(`{
+  "remote_addresses": [
+    "1.1.1.1/32"
+  ]
+}`),
+			ip:    "1.1.1.1",
+			match: true,
+		},
+		{
+			name: "bad cidr",
+			data: []byte(`{
+  "remote_addresses": [
+    "according to all laws of aviation"
+  ]
+}`),
+			err: checker.ErrUnparseableConfig,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			data := json.RawMessage(tt.data)
+
+			impl, err := f.Build(t.Context(), data)
+			if !errors.Is(err, tt.err) {
+				t.Logf("want: %v", tt.err)
+				t.Logf("got:  %v", err)
+				t.Fatal("creation didn't do what was expected")
+			}
+
+			if tt.err != nil {
+				return
+			}
+
+			r, err := http.NewRequest(http.MethodGet, "/", nil)
+			if err != nil {
+				t.Fatalf("can't make request: %v", err)
+			}
+
+			if tt.ip != "" {
+				r.Header.Add("X-Real-Ip", tt.ip)
+			}
+
+			match, err := impl.Check(r)
+
+			if tt.match != match {
+				t.Errorf("match: %v, wanted: %v", match, tt.match)
+			}
+
+			if err != nil && tt.err != nil && !errors.Is(err, tt.err) {
+				t.Errorf("err: %v, wanted: %v", err, tt.err)
+			}
+
+			if impl.Hash() == "" {
+				t.Error("hash method returns empty string")
+			}
+		})
+	}
+}

lib/checker/remoteaddress/testdata/invalid_bad_cidr.json

@@ -0,0 +1,5 @@
+{
+  "remote_addresses": [
+    "according to all laws of aviation"
+  ]
+}