✨ Transform banTemplate to add blocking reason and client IP (#290)

* ✨ Transform banTemplate to add blocking reason

* 🍱 fix test

* 🍱 fix lint

* 🍱 fix test

* 🍱 fix lint

* 🍱 fix lint

* 🍱 add doc and fix lint

* 🍱 fix lint

* 🍱 fix lint

* 🍱 fix lint

* 🍱 fix lint

* 🍱 fix lint

* 🍱 lint html

* 🍱 fix comments + fix wicketpeeker readme

* 🍱 Give ClientIP in ban page

* 🍱 fix test

.github/workflows/main.yml

@@ -24,7 +24,7 @@ jobs:
 
       # https://github.com/marketplace/actions/setup-go-environment
       - name: Set up Go ${{ env.GO_VERSION }}
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
           go-version: ${{ env.GO_VERSION }}
 

bouncer.go

@@ -9,6 +9,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	htmltemplate "html/template"
 	"io"
 	"net/http"
 	"net/url"
@@ -106,7 +107,7 @@ type Bouncer struct {
 	crowdsecStreamRoute     string
 	crowdsecHeader          string
 	redisUnreachableBlock   bool
-	banTemplateString       string
+	banTemplate             *htmltemplate.Template
 	clientPoolStrategy      *ip.PoolStrategy
 	serverPoolStrategy      *ip.PoolStrategy
 	httpClient              *http.Client
@@ -159,16 +160,9 @@ func New(_ context.Context, next http.Handler, config *configuration.Config, nam
 		config.CrowdsecLapiKey = apiKey
 	}
 
-	var banTemplateString string
+	var banTemplate *htmltemplate.Template
 	if config.BanHTMLFilePath != "" {
-		var buf bytes.Buffer
-		banTemplate, _ := configuration.GetHTMLTemplate(config.BanHTMLFilePath)
-		err = banTemplate.Execute(&buf, nil)
-		if err != nil {
-			log.Error("New:banTemplate is bad formatted " + err.Error())
-			return nil, err
-		}
-		banTemplateString = buf.String()
+		banTemplate, _ = configuration.GetHTMLTemplate(config.BanHTMLFilePath)
 	}
 
 	bouncer := &Bouncer{
@@ -198,7 +192,7 @@ func New(_ context.Context, next http.Handler, config *configuration.Config, nam
 		defaultDecisionTimeout:  config.DefaultDecisionSeconds,
 		remediationStatusCode:   config.RemediationStatusCode,
 		redisUnreachableBlock:   config.RedisCacheUnreachableBlock,
-		banTemplateString:       banTemplateString,
+		banTemplate:             banTemplate,
 		crowdsecStreamRoute:     crowdsecStreamRoute,
 		crowdsecHeader:          crowdsecHeader,
 		log:                     log,
@@ -296,13 +290,13 @@ func (bouncer *Bouncer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	remoteIP, err := ip.GetRemoteIP(req, bouncer.serverPoolStrategy, bouncer.forwardedCustomHeader)
 	if err != nil {
 		bouncer.log.Error(fmt.Sprintf("ServeHTTP:getRemoteIp ip:%s %s", remoteIP, err.Error()))
-		handleBanServeHTTP(bouncer, rw)
+		bouncer.handleBanServeHTTP(rw, req, remoteIP, configuration.ReasonTECH)
 		return
 	}
 	isTrusted, err := bouncer.clientPoolStrategy.Checker.Contains(remoteIP)
 	if err != nil {
 		bouncer.log.Error(fmt.Sprintf("ServeHTTP:checkerContains ip:%s %s", remoteIP, err.Error()))
-		handleBanServeHTTP(bouncer, rw)
+		bouncer.handleBanServeHTTP(rw, req, remoteIP, configuration.ReasonTECH)
 		return
 	}
 	// if our IP is in the trusted list we bypass the next checks
@@ -313,7 +307,7 @@ func (bouncer *Bouncer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	}
 
 	if bouncer.crowdsecMode == configuration.AppsecMode {
-		handleNextServeHTTP(bouncer, remoteIP, rw, req)
+		bouncer.handleNextServeHTTP(rw, req, remoteIP)
 		return
 	}
 
@@ -325,20 +319,20 @@ func (bouncer *Bouncer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 			bouncer.log.Debug(fmt.Sprintf("ServeHTTP:Get ip:%s isBanned:false %s", remoteIP, cacheErrString))
 			if !bouncer.redisUnreachableBlock && cacheErrString == cache.CacheUnreachable {
 				bouncer.log.Error(fmt.Sprintf("ServeHTTP:Get ip:%s redisUnreachable=true", remoteIP))
-				handleNextServeHTTP(bouncer, remoteIP, rw, req)
+				bouncer.handleNextServeHTTP(rw, req, remoteIP)
 				return
 			}
 			if cacheErrString != cache.CacheMiss {
 				bouncer.log.Error(fmt.Sprintf("ServeHTTP:Get ip:%s %s", remoteIP, cacheErrString))
-				handleBanServeHTTP(bouncer, rw)
+				bouncer.handleBanServeHTTP(rw, req, remoteIP, configuration.ReasonTECH)
 				return
 			}
 		} else {
 			bouncer.log.Debug(fmt.Sprintf("ServeHTTP ip:%s cache:hit isBanned:%v", remoteIP, value))
 			if value == cache.NoBannedValue {
-				handleNextServeHTTP(bouncer, remoteIP, rw, req)
+				bouncer.handleNextServeHTTP(rw, req, remoteIP)
 			} else {
-				handleRemediationServeHTTP(bouncer, remoteIP, value, rw, req)
+				bouncer.handleRemediationServeHTTP(rw, req, remoteIP, value)
 			}
 			return
 		}
@@ -347,18 +341,18 @@ func (bouncer *Bouncer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	// Right here if we cannot join the stream we forbid the request to go on.
 	if bouncer.crowdsecMode == configuration.StreamMode || bouncer.crowdsecMode == configuration.AloneMode {
 		if isCrowdsecStreamHealthy {
-			handleNextServeHTTP(bouncer, remoteIP, rw, req)
+			bouncer.handleNextServeHTTP(rw, req, remoteIP)
 		} else {
 			bouncer.log.Debug(fmt.Sprintf("ServeHTTP isCrowdsecStreamHealthy:false ip:%s updateFailure:%d", remoteIP, updateFailure))
-			handleBanServeHTTP(bouncer, rw)
+			bouncer.handleBanServeHTTP(rw, req, remoteIP, configuration.ReasonTECH)
 		}
 	} else {
 		value, err := handleNoStreamCache(bouncer, remoteIP)
 		if value == cache.NoBannedValue {
-			handleNextServeHTTP(bouncer, remoteIP, rw, req)
+			bouncer.handleNextServeHTTP(rw, req, remoteIP)
 		} else {
 			bouncer.log.Debug(fmt.Sprintf("ServeHTTP:handleNoStreamCache ip:%s isBanned:%v %s", remoteIP, value, err.Error()))
-			handleRemediationServeHTTP(bouncer, remoteIP, value, rw, req)
+			bouncer.handleRemediationServeHTTP(rw, req, remoteIP, value)
 		}
 	}
 }
@@ -392,43 +386,47 @@ type Login struct {
 }
 
 // To append Headers we need to call rw.WriteHeader after set any header.
-func handleBanServeHTTP(bouncer *Bouncer, rw http.ResponseWriter) {
+func (bouncer *Bouncer) handleBanServeHTTP(rw http.ResponseWriter, req *http.Request, remoteIP, reason string) {
 	atomic.AddInt64(&blockedRequests, 1)
 
 	if bouncer.remediationCustomHeader != "" {
 		rw.Header().Set(bouncer.remediationCustomHeader, "ban")
 	}
-	if bouncer.banTemplateString == "" {
+	if bouncer.banTemplate == nil {
 		rw.WriteHeader(bouncer.remediationStatusCode)
 		return
 	}
 	rw.Header().Set("Content-Type", "text/html; charset=utf-8")
 	rw.WriteHeader(bouncer.remediationStatusCode)
-	_, err := fmt.Fprint(rw, bouncer.banTemplateString)
+
+	if req.Method == http.MethodHead {
+		return
+	}
+	err := bouncer.banTemplate.Execute(rw, map[string]string{"RemediationReason": reason, "ClientIP": remoteIP})
 	if err != nil {
-		bouncer.log.Error("handleBanServeHTTP could not write template to ResponseWriter")
+		bouncer.log.Error("handleBanServeHTTP banTemplateServe " + err.Error())
 	}
 }
 
-func handleRemediationServeHTTP(bouncer *Bouncer, remoteIP, remediation string, rw http.ResponseWriter, req *http.Request) {
+func (bouncer *Bouncer) handleRemediationServeHTTP(rw http.ResponseWriter, req *http.Request, remoteIP, remediation string) {
 	bouncer.log.Debug(fmt.Sprintf("handleRemediationServeHTTP ip:%s remediation:%s", remoteIP, remediation))
-	if bouncer.captchaClient.Valid && remediation == cache.CaptchaValue {
+	if bouncer.captchaClient.Valid && remediation == cache.CaptchaValue && req.Method != http.MethodHead {
 		if bouncer.captchaClient.Check(remoteIP) {
-			handleNextServeHTTP(bouncer, remoteIP, rw, req)
+			bouncer.handleNextServeHTTP(rw, req, remoteIP)
 			return
 		}
 		atomic.AddInt64(&blockedRequests, 1) //  If we serve a captcha that should count as a dropped request.
 		bouncer.captchaClient.ServeHTTP(rw, req, remoteIP)
 		return
 	}
-	handleBanServeHTTP(bouncer, rw)
+	bouncer.handleBanServeHTTP(rw, req, remoteIP, configuration.ReasonLAPI)
 }
 
-func handleNextServeHTTP(bouncer *Bouncer, remoteIP string, rw http.ResponseWriter, req *http.Request) {
+func (bouncer *Bouncer) handleNextServeHTTP(rw http.ResponseWriter, req *http.Request, remoteIP string) {
 	if bouncer.appsecEnabled {
 		if err := appsecQuery(bouncer, remoteIP, req); err != nil {
 			bouncer.log.Debug(fmt.Sprintf("handleNextServeHTTP ip:%s isWaf:true %s", remoteIP, err.Error()))
-			handleBanServeHTTP(bouncer, rw)
+			bouncer.handleBanServeHTTP(rw, req, remoteIP, configuration.ReasonAPPSEC)
 			return
 		}
 	}
@@ -524,7 +522,7 @@ func handleNoStreamCache(bouncer *Bouncer, remoteIP string) (string, error) {
 	default:
 		bouncer.log.Debug("handleStreamCache:unknownType " + decision.Type)
 	}
-	if isLiveMode {
+	if isLiveMode && bouncer.defaultDecisionTimeout > 0 {
 		durationSecond := int64(duration.Seconds())
 		if bouncer.defaultDecisionTimeout < durationSecond {
 			durationSecond = bouncer.defaultDecisionTimeout

bouncer_test.go

@@ -2,6 +2,7 @@ package crowdsec_bouncer_traefik_plugin //nolint:revive,stylecheck
 
 import (
 	"context"
+	htmltemplate "html/template"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
@@ -186,3 +187,148 @@ func Test_crowdsecQuery(t *testing.T) {
 		})
 	}
 }
+
+func TestHandleBanServeHTTPWithDifferentMethods(t *testing.T) {
+	html := "<html>You are banned</html>"
+	banTemplate, _ := htmltemplate.New("html").Parse(html)
+	tests := []struct {
+		name              string
+		method            string
+		banTemplate       *htmltemplate.Template
+		expectBodyContent bool
+	}{
+		{
+			name:              "GET request should have body with template",
+			method:            http.MethodGet,
+			banTemplate:       banTemplate,
+			expectBodyContent: true,
+		},
+		{
+			name:              "HEAD request should NOT have body even with template",
+			method:            http.MethodHead,
+			banTemplate:       banTemplate,
+			expectBodyContent: false,
+		},
+		{
+			name:              "POST request should have body with template",
+			method:            http.MethodPost,
+			banTemplate:       banTemplate,
+			expectBodyContent: true,
+		},
+		{
+			name:              "PUT request should have body with template",
+			method:            http.MethodPut,
+			banTemplate:       banTemplate,
+			expectBodyContent: true,
+		},
+		{
+			name:              "DELETE request should have body with template",
+			method:            http.MethodDelete,
+			banTemplate:       banTemplate,
+			expectBodyContent: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			bouncer := &Bouncer{
+				remediationStatusCode:   http.StatusForbidden,
+				remediationCustomHeader: "X-Test-Remediation",
+				banTemplate:             tt.banTemplate,
+			}
+
+			rw := httptest.NewRecorder()
+			req := &http.Request{Method: tt.method}
+			bouncer.handleBanServeHTTP(rw, req, "0.0.0.0", "TEST")
+
+			// Check status code
+			if rw.Code != http.StatusForbidden {
+				t.Errorf("Expected status code 403, got %d", rw.Code)
+			}
+
+			// Check custom header
+			headerValue := rw.Header().Get("X-Test-Remediation")
+			if headerValue != "ban" {
+				t.Errorf("Expected header X-Test-Remediation to be 'ban', got %s", headerValue)
+			}
+
+			// Check body content
+			body := rw.Body.String()
+			hasBodyContent := len(body) > 0
+
+			if hasBodyContent != tt.expectBodyContent {
+				t.Errorf("Method %s: expected body content: %v, got body content: %v (body: %q)",
+					tt.method, tt.expectBodyContent, hasBodyContent, body)
+			}
+
+			// If we expect body content, verify it matches template
+			if tt.expectBodyContent && body != html {
+				t.Errorf("Expected body %q, got %q", html, body)
+			}
+		})
+	}
+}
+
+func TestCaptchaMethodBasedLogic(t *testing.T) {
+	tests := []struct {
+		name              string
+		method            string
+		remediation       string
+		expectBanFallback bool
+	}{
+		{
+			name:              "GET with captcha remediation should allow captcha",
+			method:            http.MethodGet,
+			remediation:       cache.CaptchaValue,
+			expectBanFallback: false,
+		},
+		{
+			name:              "HEAD with captcha remediation should fallback to ban",
+			method:            http.MethodHead,
+			remediation:       cache.CaptchaValue,
+			expectBanFallback: true,
+		},
+		{
+			name:              "POST with captcha remediation should allow captcha",
+			method:            http.MethodPost,
+			remediation:       cache.CaptchaValue,
+			expectBanFallback: false,
+		},
+		{
+			name:              "PUT with captcha remediation should allow captcha",
+			method:            http.MethodPut,
+			remediation:       cache.CaptchaValue,
+			expectBanFallback: false,
+		},
+		{
+			name:              "DELETE with captcha remediation should allow captcha",
+			method:            http.MethodDelete,
+			remediation:       cache.CaptchaValue,
+			expectBanFallback: false,
+		},
+		{
+			name:              "PATCH with captcha remediation should allow captcha",
+			method:            http.MethodPatch,
+			remediation:       cache.CaptchaValue,
+			expectBanFallback: false,
+		},
+		{
+			name:              "OPTIONS with captcha remediation should allow captcha",
+			method:            http.MethodOptions,
+			remediation:       cache.CaptchaValue,
+			expectBanFallback: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Test the core logic: captcha is served for all methods except HEAD
+			shouldUseCaptcha := tt.remediation == cache.CaptchaValue && tt.method != http.MethodHead
+
+			if shouldUseCaptcha == tt.expectBanFallback {
+				t.Errorf("Method %s with %s remediation: expected ban fallback %v, but logic would use captcha %v",
+					tt.method, tt.remediation, tt.expectBanFallback, shouldUseCaptcha)
+			}
+		})
+	}
+}

examples/captcha/README.md

@@ -47,7 +47,7 @@ To instruct Crowdsec to use captcha remediation, change the `/etc/crowdsec/profi
 - Return a captcha decision the first X times and then a ban decision.
 
 The second mode could be used to prevent repeated malicious activity.
-More information is available on configuring Crowdsec in the [official documentation](https://docs.crowdsec.net/docs/next/profiles/captcha_profile/).
+More information is available on configuring Crowdsec in the [official documentation](https://docs.crowdsec.net/docs/next/local_api/profiles/captcha_profile/).
 
 ```yaml
   ...

examples/custom-ban-page/README.md

@@ -45,3 +45,13 @@ To play the demo environment run:
 ```bash
 make run_custom_ban_page
 ```
+
+## Another thing to note
+In the html of the ban page, you can use:  
+- {{ .ClientIP }} to display the IP used to ban the request.  
+- {{ .RemediationReason }} that convert on runtime into why the ban page is served. It's an enum with "APPSEC", "LAPI", "TECHNICAL_ISSUE" and it is useful to help user understand why the request is blocked.  
+```
+<script>var remediation = "{{ .RemediationReason }}"</script>
+<script>var clientIp = "{{ .ClientIP }}"</script>
+```
+With the above tweak and some other js, you can customize your ban page on runtime.

examples/custom-captcha/README.md

@@ -5,7 +5,7 @@ Read the example captcha before this, to better understand what is done here.
 ### Traefik configuration
 
 The minimal configuration is defined below to implement custom captcha.  
-This documentation use https://github.com/a-ve/wicketpeeker, a self-hosted captcha provider that have a similar API than big providers.
+This documentation use https://github.com/a-ve/wicketkeeper, a self-hosted captcha provider that have a similar API than big providers.
 
 Minimal API requirement:
 
@@ -41,7 +41,6 @@ wicketkeeper:
   ports:
     - "8080:8080"
   environment:
-    - ROOT_URL=http://localhost:8080
     - LISTEN_PORT=8080
     - REDIS_ADDR=redis:6379
     - DIFFICULTY=4
@@ -55,6 +54,10 @@ redis:
   image: redis/redis-stack-server:latest
 ```
 
+```html
+<div id="captcha" class="{{ .FrontendKey }}" data-sitekey="{{ .SiteKey }}" data-callback="captchaCallback" data-challenge-url="http://captcha.localhost:8000/v0/challenge">
+```
+
 ## Exemple navigation
 
 We can try to query normally the whoami server:

examples/custom-captcha/captcha.html

@@ -294,7 +294,7 @@
         <h1 class="text-2xl lg:text-3xl xl:text-4xl">CrowdSec Captcha</h1>
       </div>
       <form action="" method="POST" class="flex flex-col items-center space-y-1" id="captcha-form">
-        <div id="captcha" class="{{ .FrontendKey }}" data-sitekey="{{ .SiteKey }}" data-callback="captchaCallback">
+        <div id="captcha" class="{{ .FrontendKey }}" data-sitekey="{{ .SiteKey }}" data-callback="captchaCallback" data-challenge-url="http://captcha.localhost:8000/v0/challenge">
         </div>
       </form>
       <div class="flex justify-center flex-wrap">

examples/custom-captcha/docker-compose.yml

@@ -82,7 +82,6 @@ services:
     image: ghcr.io/a-ve/wicketkeeper:latest
     container_name: "wicketkeeper"
     environment:
-      - ROOT_URL=http://captcha.localhost:8000
       - LISTEN_PORT=8080
       - REDIS_ADDR=redis:6379
       - DIFFICULTY=4
@@ -94,10 +93,10 @@ services:
     labels:
       - "traefik.enable=true"
       # Definition of the router
-      - "traefik.http.routers.router-wicketpeeker.rule=Host(`captcha.localhost`)"
-      - "traefik.http.routers.router-wicketpeeker.entrypoints=web"
+      - "traefik.http.routers.router-wicketkeeper.rule=Host(`captcha.localhost`)"
+      - "traefik.http.routers.router-wicketkeeper.entrypoints=web"
       # Definition of the service
-      - "traefik.http.services.service-whitekeeper.loadbalancer.server.port=8080"
+      - "traefik.http.services.service-wicketkeeper.loadbalancer.server.port=8080"
     depends_on:
       - redis
 

pkg/configuration/configuration.go

@@ -31,6 +31,9 @@ const (
 	LogDEBUG          = "DEBUG"
 	LogINFO           = "INFO"
 	LogERROR          = "ERROR"
+	ReasonTECH        = "TECHNICAL_ISSUE"
+	ReasonLAPI        = "LAPI"
+	ReasonAPPSEC      = "APPSEC"
 	HcaptchaProvider  = "hcaptcha"
 	RecaptchaProvider = "recaptcha"
 	TurnstileProvider = "turnstile"