fix(config): deprecate the report_as field for challenges

This was a bad idea when it was added and it is irresponsible to
continue to have it. It causes more UX problems than it fixes with
slight of hand.

Closes: #1310
Closes: #1307
Signed-off-by: Xe Iaso <me@xeiaso.net>

data/botPolicies.yaml

@@ -51,7 +51,6 @@ bots:
   #   action: CHALLENGE
   #   challenge:
   #     difficulty: 16 # impossible
-  #     report_as: 4    # lie to the operator
   #     algorithm: slow # intentionally waste CPU cycles and time
 
   # Requires a subscription to Thoth to use, see
@@ -249,7 +248,6 @@ thresholds:
       # https://anubis.techaro.lol/docs/admin/configuration/challenges/metarefresh
       algorithm: metarefresh
       difficulty: 1
-      report_as: 1
   # For clients that are browser-like but have either gained points from custom rules or
   # report as a standard browser.
   - name: moderate-suspicion
@@ -262,7 +260,6 @@ thresholds:
       # https://anubis.techaro.lol/docs/admin/configuration/challenges/proof-of-work
       algorithm: fast
       difficulty: 2 # two leading zeros, very fast for most clients
-      report_as: 2
   - name: mild-proof-of-work
     expression:
       all:
@@ -273,7 +270,6 @@ thresholds:
       # https://anubis.techaro.lol/docs/admin/configuration/challenges/proof-of-work
       algorithm: fast
       difficulty: 4
-      report_as: 4
   # For clients that are browser like and have gained many points from custom rules
   - name: extreme-suspicion
     expression: weight >= 30
@@ -282,4 +278,3 @@ thresholds:
       # https://anubis.techaro.lol/docs/admin/configuration/challenges/proof-of-work
       algorithm: fast
       difficulty: 6
-      report_as: 6

data/meta/default-config.yaml

@@ -35,7 +35,6 @@
 #   action: CHALLENGE
 #   challenge:
 #     difficulty: 16  # impossible
-#     report_as: 4    # lie to the operator
 #     algorithm: slow # intentionally waste CPU cycles and time
 
 # Requires a subscription to Thoth to use, see

docs/docs/CHANGELOG.md

@@ -25,6 +25,27 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Stabilize the CVE-2025-24369 regression test by always submitting an invalid proof instead of relying on random POW failures.
 - Add Polish locale ([#1292](https://github.com/TecharoHQ/anubis/pull/1309))
 
+### Deprecate `report_as` in challenge configuration
+
+Previously Anubis let you lie to users about the difficulty of a challenge to interfere with operators of malicious scrapers as a psyops attack:
+
+```yaml
+bots:
+  # Punish any bot with "bot" in the user-agent string
+  # This is known to have a high false-positive rate, use at your own risk
+  - name: generic-bot-catchall
+    user_agent_regex: (?i:bot|crawler)
+    action: CHALLENGE
+    challenge:
+      difficulty: 16 # impossible
+      report_as: 4 # lie to the operator
+      algorithm: slow # intentionally waste CPU cycles and time
+```
+
+This has turned out to be a bad idea and has been removed.
+
+If you are using this setting, you will get a warning in your logs. To remove this warning, remove this setting from your policy file.
+
 ### Logging customization
 
 Anubis now supports the ability to log to multiple backends ("sinks"). This allows you to have Anubis [log to a file](./admin/policies.mdx#file-sink) instead of just logging to standard out. You can also customize the [logging level](./admin/policies.mdx#log-levels) in the policy file:

docs/docs/admin/configuration/challenges/metarefresh.mdx

@@ -12,7 +12,6 @@ To use it in your Anubis configuration:
   action: CHALLENGE
   challenge:
     difficulty: 1 # Number of seconds to wait before refreshing the page
-    report_as: 4 # Unused by this challenge method
     algorithm: metarefresh # Specify a non-JS challenge method
 ```
 

docs/docs/admin/configuration/challenges/preact.mdx

@@ -12,7 +12,6 @@ To use it in your Anubis configuration:
   action: CHALLENGE
   challenge:
     difficulty: 1 # Number of seconds to wait before refreshing the page
-    report_as: 4 # Unused by this challenge method
     algorithm: preact
 ```
 

docs/docs/admin/configuration/thresholds.mdx

@@ -41,7 +41,6 @@ thresholds:
     challenge:
       algorithm: metarefresh
       difficulty: 1
-      report_as: 1
 
   - name: moderate-suspicion
     expression:
@@ -52,7 +51,6 @@ thresholds:
     challenge:
       algorithm: fast
       difficulty: 2
-      report_as: 2
 
   - name: extreme-suspicion
     expression: weight >= 20
@@ -60,7 +58,6 @@ thresholds:
     challenge:
       algorithm: fast
       difficulty: 4
-      report_as: 4
 ```
 
 This defines a suite of 4 thresholds:

docs/docs/admin/policies.mdx

@@ -84,7 +84,6 @@ This rule has been known to have a high false positive rate in testing. Please u
   action: CHALLENGE
   challenge:
     difficulty: 16 # impossible
-    report_as: 4 # lie to the operator
     algorithm: slow # intentionally waste CPU cycles and time
 ```
 
@@ -93,7 +92,6 @@ Challenges can be configured with these settings:
 | Key          | Example  | Description                                                                                                                                                      |
 | :----------- | :------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `difficulty` | `4`      | The challenge difficulty (number of leading zeros) for proof-of-work. See [Why does Anubis use Proof-of-Work?](/docs/design/why-proof-of-work) for more details. |
-| `report_as`  | `4`      | What difficulty the UI should report to the user. Useful for messing with industrial-scale scraping efforts.                                                     |
 | `algorithm`  | `"fast"` | The challenge method to use. See [the list of challenge methods](./configuration/challenges/) for more information.                                              |
 
 ### Remote IP based filtering

docs/manifest/cfg/anubis/botPolicies.yaml

@@ -49,7 +49,6 @@ bots:
   #   action: CHALLENGE
   #   challenge:
   #     difficulty: 16  # impossible
-  #     report_as: 4    # lie to the operator
   #     algorithm: slow # intentionally waste CPU cycles and time
 
   - name: rss-feed-blog
@@ -105,7 +104,6 @@ thresholds:
       # https://anubis.techaro.lol/docs/admin/configuration/challenges/metarefresh
       algorithm: metarefresh
       difficulty: 1
-      report_as: 1
   # For clients that are browser-like but have either gained points from custom rules or
   # report as a standard browser.
   - name: moderate-suspicion
@@ -122,7 +120,6 @@ thresholds:
       # challenge data, and forwards that to the client.
       algorithm: preact
       difficulty: 1
-      report_as: 1
   - name: mild-proof-of-work
     expression:
       all:
@@ -133,7 +130,6 @@ thresholds:
       # https://anubis.techaro.lol/docs/admin/configuration/challenges/proof-of-work
       algorithm: fast
       difficulty: 2 # two leading zeros, very fast for most clients
-      report_as: 2
   # For clients that are browser like and have gained many points from custom rules
   - name: extreme-suspicion
     expression: weight >= 30
@@ -142,7 +138,6 @@ thresholds:
       # https://anubis.techaro.lol/docs/admin/configuration/challenges/proof-of-work
       algorithm: fast
       difficulty: 4
-      report_as: 4
 
 dnsbl: false
 

lib/anubis.go

@@ -167,8 +167,8 @@ func (s *Server) hydrateChallengeRule(rule *policy.Bot, chall *challenge.Challen
 	if rule.Challenge.Difficulty == 0 {
 		rule.Challenge.Difficulty = chall.Difficulty
 	}
-	if rule.Challenge.ReportAs == 0 {
+	if rule.Challenge.ReportAs != 0 {
-		rule.Challenge.ReportAs = chall.Difficulty
+		s.logger.Warn("[DEPRECATION] the report_as field in this bot rule is deprecated, see https://github.com/TecharoHQ/anubis/issues/1310 for more information", "bot_name", rule.Name, "difficulty", rule.Challenge.Difficulty, "report_as", rule.Challenge.ReportAs)
 	}
 	if rule.Challenge.Algorithm == "" {
 		rule.Challenge.Algorithm = chall.Method
@@ -648,7 +648,6 @@ func (s *Server) check(r *http.Request, lg *slog.Logger) (policy.CheckResult, *p
 	return cr("default/allow", config.RuleAllow, weight), &policy.Bot{
 		Challenge: &config.ChallengeRules{
 			Difficulty: s.policy.DefaultDifficulty,
-			ReportAs:   s.policy.DefaultDifficulty,
 			Algorithm:  config.DefaultAlgorithm,
 		},
 		Rules: &checker.List{},

lib/anubis_test.go

@@ -464,10 +464,6 @@ func TestCheckDefaultDifficultyMatchesPolicy(t *testing.T) {
 			if bot.Challenge.Difficulty != i {
 				t.Errorf("Challenge.Difficulty is wrong, wanted %d, got: %d", i, bot.Challenge.Difficulty)
 			}
-
-			if bot.Challenge.ReportAs != i {
-				t.Errorf("Challenge.ReportAs is wrong, wanted %d, got: %d", i, bot.Challenge.ReportAs)
-			}
 		})
 	}
 }

lib/challenge/proofofwork/proofofwork_test.go

@@ -36,7 +36,6 @@ func TestBasic(t *testing.T) {
 		Challenge: &config.ChallengeRules{
 			Algorithm:  "fast",
 			Difficulty: 0,
-			ReportAs:   0,
 		},
 	}
 	const challengeStr = "hunter"

lib/config/config_test.go

@@ -110,7 +110,6 @@ func TestBotValid(t *testing.T) {
 				PathRegex: p("Mozilla"),
 				Challenge: &ChallengeRules{
 					Difficulty: -1,
-					ReportAs:   4,
 					Algorithm:  "fast",
 				},
 			},
@@ -124,7 +123,6 @@ func TestBotValid(t *testing.T) {
 				PathRegex: p("Mozilla"),
 				Challenge: &ChallengeRules{
 					Difficulty: 420,
-					ReportAs:   4,
 					Algorithm:  "fast",
 				},
 			},
@@ -361,7 +359,6 @@ func TestBotConfigZero(t *testing.T) {
 
 	b.Challenge = &ChallengeRules{
 		Difficulty: 4,
-		ReportAs:   4,
 		Algorithm:  DefaultAlgorithm,
 	}
 	if b.Zero() {

lib/config/testdata/good/thresholds.yaml

@@ -18,7 +18,6 @@ thresholds:
     challenge:
       algorithm: metarefresh
       difficulty: 1
-      report_as: 1
   - name: moderate-suspicion
     expression:
       all:
@@ -28,11 +27,9 @@ thresholds:
     challenge:
       algorithm: fast
       difficulty: 2
-      report_as: 2
   - name: extreme-suspicion
     expression: weight >= 20
     action: CHALLENGE
     challenge:
       algorithm: fast
       difficulty: 4
-      report_as: 4

lib/config/threshold.go

@@ -24,7 +24,6 @@ var (
 			Challenge: &ChallengeRules{
 				Algorithm:  "fast",
 				Difficulty: anubis.DefaultDifficulty,
-				ReportAs:   anubis.DefaultDifficulty,
 			},
 		},
 	}

lib/config/threshold_test.go

@@ -32,7 +32,6 @@ func TestThresholdValid(t *testing.T) {
 				Challenge: &ChallengeRules{
 					Algorithm:  "fast",
 					Difficulty: 1,
-					ReportAs:   1,
 				},
 			},
 			err: nil,

lib/policy/policy.go

@@ -145,7 +145,6 @@ func ParseConfig(ctx context.Context, fin io.Reader, fname string, defaultDiffic
 		if b.Challenge == nil {
 			parsedBot.Challenge = &config.ChallengeRules{
 				Difficulty: defaultDifficulty,
-				ReportAs:   defaultDifficulty,
 				Algorithm:  "fast",
 			}
 		} else {

lib/testdata/invalid-challenge-method.yaml

@@ -4,5 +4,4 @@ bots:
     action: CHALLENGE
     challenge:
       difficulty: 16
-      report_as: 4
       algorithm: hunter2 # invalid algorithm

lib/testdata/test_config.yaml

@@ -42,4 +42,3 @@ thresholds:
     challenge:
       algorithm: fast
       difficulty: 1
-      report_as: 1

lib/testdata/zero_difficulty.yaml

@@ -42,4 +42,3 @@ thresholds:
     challenge:
       algorithm: fast
       difficulty: 0
-      report_as: 0

test/palemoon/anubis/anubis.yaml

@@ -4,7 +4,6 @@ bots:
     action: CHALLENGE
     challenge:
       difficulty: 2
-      report_as: 2
       algorithm: fast
 
 status_codes:

web/js/main.ts

@@ -155,7 +155,7 @@ const t = (key) => translations[`js_${key}`] || translations[key] || key;
     return;
   }
 
-  status.innerHTML = `${t('calculating_difficulty')} ${rules.report_as}, `;
+  status.innerHTML = `${t('calculating_difficulty')} ${rules.difficulty}, `;
   progress.style.display = "inline-block";
 
   // the whole text, including "Speed:", as a single node, because some browsers
@@ -166,7 +166,7 @@ const t = (key) => translations[`js_${key}`] || translations[key] || key;
 
   let lastSpeedUpdate = 0;
   let showingApology = false;
-  const likelihood = Math.pow(16, -rules.report_as);
+  const likelihood = Math.pow(16, -rules.difficulty);
 
   try {
     const t0 = Date.now();