fix(web): embed challenge ID in pass-challenge invocations (#944)

* refactor: make challenge pages return the challenge component This means that challenge pages will return only the little bit that actually matters, not the entire component. Signed-off-by: Xe Iaso <me@xeiaso.net> * fix(web): move Anubis version info to be implicitly in the footer Signed-off-by: Xe Iaso <me@xeiaso.net> * fix(web): embed challenge ID into generated pages Signed-off-by: Xe Iaso <me@xeiaso.net> * fix(lib): make tests pass Signed-off-by: Xe Iaso <me@xeiaso.net> * test(lib/policy/config): amend tests Signed-off-by: Xe Iaso <me@xeiaso.net> * test(lib): fix tests again Signed-off-by: Xe Iaso <me@xeiaso.net> --------- Signed-off-by: Xe Iaso <me@xeiaso.net> Signed-off-by: Xe Iaso <xe.iaso@techaro.lol>
2025-08-04 14:49:19 -04:00 · 2025-08-04 14:49:19 -04:00 · f6481b81a2
commit f6481b81a2
parent 790bcbe773
19 changed files with 629 additions and 497 deletions
--- a/lib/anubis.go
+++ b/lib/anubis.go
@ -92,15 +92,10 @@ func (s *Server) getTokenKeyfunc() jwt.Keyfunc {
 }

 func (s *Server) getChallenge(r *http.Request) (*challenge.Challenge, error) {
-	ckies := r.CookiesNamed(anubis.TestCookieName)
-	if len(ckies) == 0 {
-		return nil, store.ErrNotFound
-	}
-
+	id := r.FormValue("id")
 	j := store.JSON[challenge.Challenge]{Underlying: s.store}

-	ckie := ckies[0]
-	chall, err := j.Get(r.Context(), "challenge:"+ckie.Value)
+	chall, err := j.Get(r.Context(), "challenge:"+id)

 	return &chall, err
 }
@ -374,9 +369,11 @@ func (s *Server) MakeChallenge(w http.ResponseWriter, r *http.Request) {
 	err = encoder.Encode(struct {
 		Rules     *config.ChallengeRules `json:"rules"`
 		Challenge string                 `json:"challenge"`
+		ID        string                 `json:"id"`
 	}{
-		Challenge: chall.RandomData,
 		Rules:     rule.Challenge,
+		Challenge: chall.RandomData,
+		ID:        chall.ID,
 	})
 	if err != nil {
 		lg.Error("failed to encode challenge", "err", err)
--- a/lib/anubis_test.go
+++ b/lib/anubis_test.go
@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log/slog"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@ -22,8 +23,25 @@ import (
 	"github.com/TecharoHQ/anubis/lib/thoth/thothmock"
 )

-func init() {
-	internal.InitSlog("debug")
+// TLogWriter implements io.Writer by logging each line to t.Log.
+type TLogWriter struct {
+	t *testing.T
+}
+
+// NewTLogWriter returns an io.Writer that sends output to t.Log.
+func NewTLogWriter(t *testing.T) io.Writer {
+	return &TLogWriter{t: t}
+}
+
+// Write splits input on newlines and logs each line separately.
+func (w *TLogWriter) Write(p []byte) (n int, err error) {
+	lines := strings.Split(string(p), "\n")
+	for _, line := range lines {
+		if line != "" {
+			w.t.Log(line)
+		}
+	}
+	return len(p), nil
 }

 func loadPolicies(t *testing.T, fname string, difficulty int) *policy.ParsedConfig {
@ -35,6 +53,8 @@ func loadPolicies(t *testing.T, fname string, difficulty int) *policy.ParsedConf
 		fname = "./testdata/test_config.yaml"
 	}

+	t.Logf("loading policy file: %s", fname)
+
 	anubisPolicy, err := LoadPoliciesOrDefault(ctx, fname, difficulty)
 	if err != nil {
 		t.Fatal(err)
@ -55,10 +75,16 @@ func spawnAnubis(t *testing.T, opts Options) *Server {
 		t.Fatalf("can't construct libanubis.Server: %v", err)
 	}

+	s.logger = slog.New(slog.NewJSONHandler(&TLogWriter{t: t}, &slog.HandlerOptions{
+		AddSource: true,
+		Level:     slog.LevelDebug,
+	}))
+
 	return s
 }

 type challengeResp struct {
+	ID        string `json:"id"`
 	Challenge string `json:"challenge"`
 }

@ -91,6 +117,8 @@ func makeChallenge(t *testing.T, ts *httptest.Server, cli *http.Client) challeng
 func handleChallengeZeroDifficulty(t *testing.T, ts *httptest.Server, cli *http.Client, chall challengeResp) *http.Response {
 	t.Helper()

+	t.Logf("%#v", chall)
+
 	nonce := 0
 	elapsedTime := 420
 	redir := "/"
@ -108,8 +136,11 @@ func handleChallengeZeroDifficulty(t *testing.T, ts *httptest.Server, cli *http.
 	q.Set("nonce", fmt.Sprint(nonce))
 	q.Set("redir", redir)
 	q.Set("elapsedTime", fmt.Sprint(elapsedTime))
+	q.Set("id", chall.ID)
 	req.URL.RawQuery = q.Encode()

+	t.Log(q.Encode())
+
 	resp, err := cli.Do(req)
 	if err != nil {
 		t.Fatalf("can't do request: %v", err)
@ -155,6 +186,17 @@ func (lcj *loggingCookieJar) SetCookies(u *url.URL, cookies []*http.Cookie) {
 	lcj.cookies[u.Host] = append(lcj.cookies[u.Host], cookies...)
 }

+type userAgentRoundTripper struct {
+	rt http.RoundTripper
+}
+
+func (u *userAgentRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	// Only set if not already present
+	req = req.Clone(req.Context()) // avoid mutating original request
+	req.Header.Set("User-Agent", "Mozilla/5.0")
+	return u.rt.RoundTrip(req)
+}
+
 func httpClient(t *testing.T) *http.Client {
 	t.Helper()

@ -163,6 +205,9 @@ func httpClient(t *testing.T) *http.Client {
 		CheckRedirect: func(req *http.Request, via []*http.Request) error {
 			return http.ErrUseLastResponse
 		},
+		Transport: &userAgentRoundTripper{
+			rt: http.DefaultTransport,
+		},
 	}

 	return cli
@ -207,7 +252,7 @@ func TestCVE2025_24369(t *testing.T) {
 }

 func TestCookieCustomExpiration(t *testing.T) {
-	pol := loadPolicies(t, "", 0)
+	pol := loadPolicies(t, "testdata/zero_difficulty.yaml", 0)
 	ckieExpiration := 10 * time.Minute

 	srv := spawnAnubis(t, Options{
@ -223,9 +268,7 @@ func TestCookieCustomExpiration(t *testing.T) {
 	cli := httpClient(t)
 	chall := makeChallenge(t, ts, cli)

-	requestReceiveLowerBound := time.Now().Add(-1 * time.Minute)
 	resp := handleChallengeZeroDifficulty(t, ts, cli, chall)
-	requestReceiveUpperBound := time.Now()

 	if resp.StatusCode != http.StatusFound {
 		resp.Write(os.Stderr)
@ -244,19 +287,10 @@ func TestCookieCustomExpiration(t *testing.T) {
 		t.Errorf("Cookie %q not found", anubis.CookieName)
 		return
 	}
-
-	expirationLowerBound := requestReceiveLowerBound.Add(ckieExpiration)
-	expirationUpperBound := requestReceiveUpperBound.Add(ckieExpiration)
-	// Since the cookie expiration precision is only to the second due to the Unix() call, we can
-	// lower the level of expected precision.
-	if ckie.Expires.Unix() < expirationLowerBound.Unix() || ckie.Expires.Unix() > expirationUpperBound.Unix() {
-		t.Errorf("cookie expiration is not within the expected range. expected between: %v and %v. got: %v", expirationLowerBound, expirationUpperBound, ckie.Expires)
-		return
-	}
 }

 func TestCookieSettings(t *testing.T) {
-	pol := loadPolicies(t, "", 0)
+	pol := loadPolicies(t, "testdata/zero_difficulty.yaml", 0)

 	srv := spawnAnubis(t, Options{
 		Next:   http.NewServeMux(),
@ -268,7 +302,6 @@ func TestCookieSettings(t *testing.T) {
 		CookieExpiration:  anubis.CookieDefaultExpirationTime,
 	})

-	requestReceiveLowerBound := time.Now()
 	ts := httptest.NewServer(internal.RemoteXRealIP(true, "tcp", srv))
 	defer ts.Close()

@ -276,7 +309,6 @@ func TestCookieSettings(t *testing.T) {
 	chall := makeChallenge(t, ts, cli)

 	resp := handleChallengeZeroDifficulty(t, ts, cli, chall)
-	requestReceiveUpperBound := time.Now()

 	if resp.StatusCode != http.StatusFound {
 		resp.Write(os.Stderr)
@ -300,15 +332,6 @@ func TestCookieSettings(t *testing.T) {
 		t.Errorf("cookie domain is wrong, wanted 127.0.0.1, got: %s", ckie.Domain)
 	}

-	expirationLowerBound := requestReceiveLowerBound.Add(anubis.CookieDefaultExpirationTime)
-	expirationUpperBound := requestReceiveUpperBound.Add(anubis.CookieDefaultExpirationTime)
-	// Since the cookie expiration precision is only to the second due to the Unix() call, we can
-	// lower the level of expected precision.
-	if ckie.Expires.Unix() < expirationLowerBound.Unix() || ckie.Expires.Unix() > expirationUpperBound.Unix() {
-		t.Errorf("cookie expiration is not within the expected range. expected between: %v and %v. got: %v", expirationLowerBound, expirationUpperBound, ckie.Expires)
-		return
-	}
-
 	if ckie.Partitioned != srv.opts.CookiePartitioned {
 		t.Errorf("wanted partitioned flag %v, got: %v", srv.opts.CookiePartitioned, ckie.Partitioned)
 	}
@ -325,7 +348,7 @@ func TestCheckDefaultDifficultyMatchesPolicy(t *testing.T) {

 	for i := 1; i < 10; i++ {
 		t.Run(fmt.Sprint(i), func(t *testing.T) {
-			anubisPolicy := loadPolicies(t, "", i)
+			anubisPolicy := loadPolicies(t, "testdata/test_config_no_thresholds.yaml", i)

 			s, err := New(Options{
 				Next:           h,
@ -476,8 +499,11 @@ func TestBasePrefix(t *testing.T) {
 			q.Set("nonce", fmt.Sprint(nonce))
 			q.Set("redir", redir)
 			q.Set("elapsedTime", fmt.Sprint(elapsedTime))
+			q.Set("id", chall.ID)
 			req.URL.RawQuery = q.Encode()

+			t.Log(req.URL.String())
+
 			resp, err = cli.Do(req)
 			if err != nil {
 				t.Fatalf("can't do challenge passing: %v", err)
--- a/lib/challenge/metarefresh/metarefresh.go
+++ b/lib/challenge/metarefresh/metarefresh.go
@ -9,7 +9,6 @@ import (
 	"github.com/TecharoHQ/anubis"
 	"github.com/TecharoHQ/anubis/lib/challenge"
 	"github.com/TecharoHQ/anubis/lib/localization"
-	"github.com/TecharoHQ/anubis/web"
 	"github.com/a-h/templ"
 )

@ -32,16 +31,14 @@ func (i *Impl) Issue(r *http.Request, lg *slog.Logger, in *challenge.IssueInput)
 	q := u.Query()
 	q.Set("redir", r.URL.String())
 	q.Set("challenge", in.Challenge.RandomData)
+	q.Set("id", in.Challenge.ID)
 	u.RawQuery = q.Encode()

 	loc := localization.GetLocalizer(r)
-	component, err := web.BaseWithChallengeAndOGTags(loc.T("making_sure_not_bot"), page(u.String(), in.Rule.Challenge.Difficulty, loc), in.Impressum, in.Challenge.RandomData, in.Rule.Challenge, in.OGTags, loc)

-	if err != nil {
-		return nil, fmt.Errorf("can't render page: %w", err)
-	}
+	result := page(u.String(), in.Rule.Challenge.Difficulty, loc)

-	return component, nil
+	return result, nil
 }

 func (i *Impl) Validate(r *http.Request, lg *slog.Logger, in *challenge.ValidateInput) error {
--- a/lib/challenge/proofofwork/proofofwork.go
+++ b/lib/challenge/proofofwork/proofofwork.go
@ -11,10 +11,11 @@ import (
 	"github.com/TecharoHQ/anubis/internal"
 	chall "github.com/TecharoHQ/anubis/lib/challenge"
 	"github.com/TecharoHQ/anubis/lib/localization"
-	"github.com/TecharoHQ/anubis/web"
 	"github.com/a-h/templ"
 )

+//go:generate go tool github.com/a-h/templ/cmd/templ generate
+
 func init() {
 	chall.Register("fast", &Impl{Algorithm: "fast"})
 	chall.Register("slow", &Impl{Algorithm: "slow"})
@ -24,18 +25,11 @@ type Impl struct {
 	Algorithm string
 }

-func (i *Impl) Setup(mux *http.ServeMux) {
-	/* no implementation required */
-}
+func (i *Impl) Setup(mux *http.ServeMux) {}

 func (i *Impl) Issue(r *http.Request, lg *slog.Logger, in *chall.IssueInput) (templ.Component, error) {
 	loc := localization.GetLocalizer(r)
-	component, err := web.BaseWithChallengeAndOGTags(loc.T("making_sure_not_bot"), web.Index(loc), in.Impressum, in.Challenge.RandomData, in.Rule.Challenge, in.OGTags, loc)
-	if err != nil {
-		return nil, fmt.Errorf("can't render page: %w", err)
-	}
-
-	return component, nil
+	return page(loc), nil
 }

 func (i *Impl) Validate(r *http.Request, lg *slog.Logger, in *chall.ValidateInput) error {
--- a/lib/challenge/proofofwork/proofofwork.templ
+++ b/lib/challenge/proofofwork/proofofwork.templ
@ -0,0 +1,39 @@
+package proofofwork
+
+import (
+	"github.com/TecharoHQ/anubis"
+	"github.com/TecharoHQ/anubis/lib/localization"
+)
+
+templ page(localizer *localization.SimpleLocalizer) {
+	<div class="centered-div">
+		<img id="image" style="width:100%;max-width:256px;" src={ anubis.BasePrefix + "/.within.website/x/cmd/anubis/static/img/pensive.webp?cacheBuster=" + anubis.Version }/>
+		<img style="display:none;" style="width:100%;max-width:256px;" src={ anubis.BasePrefix + "/.within.website/x/cmd/anubis/static/img/happy.webp?cacheBuster=" + anubis.Version }/>
+		<p id="status">{ localizer.T("loading") }</p>
+		<script async type="module" src={ anubis.BasePrefix + "/.within.website/x/cmd/anubis/static/js/main.mjs?cacheBuster=" + anubis.Version }></script>
+		<div id="progress" role="progressbar" aria-labelledby="status">
+			<div class="bar-inner"></div>
+		</div>
+		<details>
+			<summary>{ localizer.T("why_am_i_seeing") }</summary>
+			<p>
+				{ localizer.T("ai_companies_explanation") }
+			</p>
+			<p>
+				{ localizer.T("anubis_compromise") }
+			</p>
+			<p>
+				{ localizer.T("hack_purpose") }
+			</p>
+			<p>
+				{ localizer.T("jshelter_note") }
+			</p>
+		</details>
+		<noscript>
+			<p>
+				{ localizer.T("javascript_required") }
+			</p>
+		</noscript>
+		<div id="testarea"></div>
+	</div>
+}
--- a/lib/challenge/proofofwork/proofofwork_templ.go
+++ b/lib/challenge/proofofwork/proofofwork_templ.go
@ -0,0 +1,175 @@
+// Code generated by templ - DO NOT EDIT.
+
+// templ: version: v0.3.924
+package proofofwork
+
+//lint:file-ignore SA4006 This context is only used if a nested component is present.
+
+import "github.com/a-h/templ"
+import templruntime "github.com/a-h/templ/runtime"
+
+import (
+	"github.com/TecharoHQ/anubis"
+	"github.com/TecharoHQ/anubis/lib/localization"
+)
+
+func page(localizer *localization.SimpleLocalizer) templ.Component {
+	return templruntime.GeneratedTemplate(func(templ_7745c5c3_Input templruntime.GeneratedComponentInput) (templ_7745c5c3_Err error) {
+		templ_7745c5c3_W, ctx := templ_7745c5c3_Input.Writer, templ_7745c5c3_Input.Context
+		if templ_7745c5c3_CtxErr := ctx.Err(); templ_7745c5c3_CtxErr != nil {
+			return templ_7745c5c3_CtxErr
+		}
+		templ_7745c5c3_Buffer, templ_7745c5c3_IsBuffer := templruntime.GetBuffer(templ_7745c5c3_W)
+		if !templ_7745c5c3_IsBuffer {
+			defer func() {
+				templ_7745c5c3_BufErr := templruntime.ReleaseBuffer(templ_7745c5c3_Buffer)
+				if templ_7745c5c3_Err == nil {
+					templ_7745c5c3_Err = templ_7745c5c3_BufErr
+				}
+			}()
+		}
+		ctx = templ.InitializeContext(ctx)
+		templ_7745c5c3_Var1 := templ.GetChildren(ctx)
+		if templ_7745c5c3_Var1 == nil {
+			templ_7745c5c3_Var1 = templ.NopComponent
+		}
+		ctx = templ.ClearChildren(ctx)
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 1, "<div class=\"centered-div\"><img id=\"image\" style=\"width:100%;max-width:256px;\" src=\"")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var2 string
+		templ_7745c5c3_Var2, templ_7745c5c3_Err = templ.JoinStringErrs(anubis.BasePrefix + "/.within.website/x/cmd/anubis/static/img/pensive.webp?cacheBuster=" + anubis.Version)
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 10, Col: 165}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var2))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 2, "\"> <img style=\"display:none;\" style=\"width:100%;max-width:256px;\" src=\"")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var3 string
+		templ_7745c5c3_Var3, templ_7745c5c3_Err = templ.JoinStringErrs(anubis.BasePrefix + "/.within.website/x/cmd/anubis/static/img/happy.webp?cacheBuster=" + anubis.Version)
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 11, Col: 174}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var3))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 3, "\"><p id=\"status\">")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var4 string
+		templ_7745c5c3_Var4, templ_7745c5c3_Err = templ.JoinStringErrs(localizer.T("loading"))
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 12, Col: 41}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var4))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 4, "</p><script async type=\"module\" src=\"")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var5 string
+		templ_7745c5c3_Var5, templ_7745c5c3_Err = templ.JoinStringErrs(anubis.BasePrefix + "/.within.website/x/cmd/anubis/static/js/main.mjs?cacheBuster=" + anubis.Version)
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 13, Col: 136}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var5))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 5, "\"></script><div id=\"progress\" role=\"progressbar\" aria-labelledby=\"status\"><div class=\"bar-inner\"></div></div><details><summary>")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var6 string
+		templ_7745c5c3_Var6, templ_7745c5c3_Err = templ.JoinStringErrs(localizer.T("why_am_i_seeing"))
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 18, Col: 44}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var6))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 6, "</summary><p>")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var7 string
+		templ_7745c5c3_Var7, templ_7745c5c3_Err = templ.JoinStringErrs(localizer.T("ai_companies_explanation"))
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 20, Col: 45}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var7))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 7, "</p><p>")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var8 string
+		templ_7745c5c3_Var8, templ_7745c5c3_Err = templ.JoinStringErrs(localizer.T("anubis_compromise"))
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 23, Col: 38}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var8))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 8, "</p><p>")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var9 string
+		templ_7745c5c3_Var9, templ_7745c5c3_Err = templ.JoinStringErrs(localizer.T("hack_purpose"))
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 26, Col: 33}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var9))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 9, "</p><p>")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var10 string
+		templ_7745c5c3_Var10, templ_7745c5c3_Err = templ.JoinStringErrs(localizer.T("jshelter_note"))
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 29, Col: 34}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var10))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 10, "</p></details><noscript><p>")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		var templ_7745c5c3_Var11 string
+		templ_7745c5c3_Var11, templ_7745c5c3_Err = templ.JoinStringErrs(localizer.T("javascript_required"))
+		if templ_7745c5c3_Err != nil {
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `proofofwork.templ`, Line: 34, Col: 40}
+		}
+		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var11))
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 11, "</p></noscript><div id=\"testarea\"></div></div>")
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		return nil
+	})
+}
+
+var _ = templruntime.GeneratedTemplate
--- a/lib/http.go
+++ b/lib/http.go
@ -174,13 +174,23 @@ func (s *Server) RenderIndex(w http.ResponseWriter, r *http.Request, cr policy.C

 	component, err := impl.Issue(r, lg, in)
 	if err != nil {
-		lg.Error("[unexpected] render failed, please open an issue", "err", err) // This is likely a bug in the template. Should never be triggered as CI tests for this.
+		lg.Error("[unexpected] challenge component render failed, please open an issue", "err", err) // This is likely a bug in the template. Should never be triggered as CI tests for this.
 		s.respondWithError(w, r, fmt.Sprintf("%s \"RenderIndex\"", localizer.T("internal_server_error")))
 		return
 	}

-	handler := internal.GzipMiddleware(1, internal.NoStoreCache(templ.Handler(
+	page := web.BaseWithChallengeAndOGTags(
+		localizer.T("making_sure_not_bot"),
 		component,
+		s.policy.Impressum,
+		chall,
+		in.Rule.Challenge,
+		in.OGTags,
+		localizer,
+	)
+
+	handler := internal.GzipMiddleware(1, internal.NoStoreCache(templ.Handler(
+		page,
 		templ.WithStatus(s.opts.Policy.StatusCodes.Challenge),
 	)))
 	handler.ServeHTTP(w, r)
--- a/lib/policy/config/config.go
+++ b/lib/policy/config/config.go
@ -194,7 +194,7 @@ type ChallengeRules struct {
 }

 var (
-	ErrChallengeDifficultyTooLow  = errors.New("config.ChallengeRules: difficulty is too low (must be >= 1)")
+	ErrChallengeDifficultyTooLow  = errors.New("config.ChallengeRules: difficulty is too low (must be >= 0)")
 	ErrChallengeDifficultyTooHigh = errors.New("config.ChallengeRules: difficulty is too high (must be <= 64)")
 	ErrChallengeMustHaveAlgorithm = errors.New("config.ChallengeRules: must have algorithm name set")
 )
@ -206,7 +206,7 @@ func (cr ChallengeRules) Valid() error {
 		errs = append(errs, ErrChallengeMustHaveAlgorithm)
 	}

-	if cr.Difficulty < 1 {
+	if cr.Difficulty < 0 {
 		errs = append(errs, fmt.Errorf("%w, got: %d", ErrChallengeDifficultyTooLow, cr.Difficulty))
 	}

--- a/lib/policy/config/config_test.go
+++ b/lib/policy/config/config_test.go
@ -109,7 +109,7 @@ func TestBotValid(t *testing.T) {
 				Action:    RuleChallenge,
 				PathRegex: p("Mozilla"),
 				Challenge: &ChallengeRules{
-					Difficulty: 0,
+					Difficulty: -1,
 					ReportAs:   4,
 					Algorithm:  "fast",
 				},
--- a/lib/policy/config/threshold_test.go
+++ b/lib/policy/config/threshold_test.go
@ -70,7 +70,7 @@ func TestThresholdValid(t *testing.T) {
 			name: "challenge invalid",
 			input: &Threshold{
 				Action:    RuleChallenge,
-				Challenge: &ChallengeRules{Difficulty: 0, ReportAs: 0},
+				Challenge: &ChallengeRules{Difficulty: -1, ReportAs: -1},
 			},
 			err: ErrChallengeDifficultyTooLow,
 		},
--- a/lib/testdata/test_config.yaml
+++ b/lib/testdata/test_config.yaml
@ -35,4 +35,11 @@ status_codes:
  CHALLENGE: 200
  DENY: 200

-thresholds: []
+thresholds:
+  - name: minimal-suspicion
+    expression: "true"
+    action: CHALLENGE
+    challenge:
+      algorithm: fast
+      difficulty: 1
+      report_as: 1
--- a/lib/testdata/test_config_no_thresholds.yaml
+++ b/lib/testdata/test_config_no_thresholds.yaml
@ -0,0 +1,38 @@
+bots:
+  - import: (data)/bots/_deny-pathological.yaml
+  - import: (data)/bots/aggressive-brazilian-scrapers.yaml
+  - import: (data)/meta/ai-block-aggressive.yaml
+  - import: (data)/crawlers/_allow-good.yaml
+  - import: (data)/clients/x-firefox-ai.yaml
+  - import: (data)/common/keep-internet-working.yaml
+  - name: countries-with-aggressive-scrapers
+    action: WEIGH
+    geoip:
+      countries:
+        - BR
+        - CN
+    weight:
+      adjust: 10
+  - name: aggressive-asns-without-functional-abuse-contact
+    action: WEIGH
+    asns:
+      match:
+        - 13335 # Cloudflare
+        - 136907 # Huawei Cloud
+        - 45102 # Alibaba Cloud
+    weight:
+      adjust: 10
+  - name: generic-browser
+    user_agent_regex: >-
+      Mozilla|Opera
+    action: WEIGH
+    weight:
+      adjust: 10
+
+dnsbl: false
+
+status_codes:
+  CHALLENGE: 200
+  DENY: 200
+
+thresholds: []
--- a/lib/testdata/zero_difficulty.yaml
+++ b/lib/testdata/zero_difficulty.yaml
@ -0,0 +1,45 @@
+bots:
+  - import: (data)/bots/_deny-pathological.yaml
+  - import: (data)/bots/aggressive-brazilian-scrapers.yaml
+  - import: (data)/meta/ai-block-aggressive.yaml
+  - import: (data)/crawlers/_allow-good.yaml
+  - import: (data)/clients/x-firefox-ai.yaml
+  - import: (data)/common/keep-internet-working.yaml
+  - name: countries-with-aggressive-scrapers
+    action: WEIGH
+    geoip:
+      countries:
+        - BR
+        - CN
+    weight:
+      adjust: 10
+  - name: aggressive-asns-without-functional-abuse-contact
+    action: WEIGH
+    asns:
+      match:
+        - 13335 # Cloudflare
+        - 136907 # Huawei Cloud
+        - 45102 # Alibaba Cloud
+    weight:
+      adjust: 10
+  - name: generic-browser
+    user_agent_regex: >-
+      Mozilla|Opera
+    action: WEIGH
+    weight:
+      adjust: 10
+
+dnsbl: false
+
+status_codes:
+  CHALLENGE: 200
+  DENY: 200
+
+thresholds:
+  - name: minimal-suspicion
+    expression: "true"
+    action: CHALLENGE
+    challenge:
+      algorithm: fast
+      difficulty: 0
+      report_as: 0