From efc39573e4347e4753fcc1cb0fbcaad7785178ee Mon Sep 17 00:00:00 2001
From: Jon Chambers <jon@signal.org>
Date: Tue, 31 Mar 2026 12:41:42 -0400
Subject: [PATCH] Use `CaptchaMetrics` to measure captcha scores for sending
 messages and verification

---
 .../captcha/AssessmentResult.java             |  3 +++
 .../controllers/VerificationController.java   |  6 +++++
 .../limits/RateLimitChallengeManager.java     | 22 +++++++++++++++----
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/captcha/AssessmentResult.java b/service/src/main/java/org/whispersystems/textsecuregcm/captcha/AssessmentResult.java
index 4a3fd9334..de0a26d41 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/captcha/AssessmentResult.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/captcha/AssessmentResult.java
@@ -93,6 +93,9 @@ public class AssessmentResult {
     return this.actualScore;
   }
 
+  public int getNormalizedIntScore() {
+    return normalizedIntScore(this.actualScore);
+  }
 
   /**
    * Map a captcha score in [0.0, 1.0] to a low cardinality discrete space in [0, 100] suitable for use in metrics
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/VerificationController.java b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/VerificationController.java
index d1ad672ff..9109003e4 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/VerificationController.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/VerificationController.java
@@ -77,6 +77,7 @@ import org.whispersystems.textsecuregcm.entities.VerificationSessionResponse;
 import org.whispersystems.textsecuregcm.filters.RemoteAddressFilter;
 import org.whispersystems.textsecuregcm.limits.RateLimiters;
 import org.whispersystems.textsecuregcm.mappers.RegistrationServiceSenderExceptionMapper;
+import org.whispersystems.textsecuregcm.metrics.CaptchaMetrics;
 import org.whispersystems.textsecuregcm.metrics.DevicePlatformUtil;
 import org.whispersystems.textsecuregcm.metrics.UserAgentTagUtil;
 import org.whispersystems.textsecuregcm.push.PushNotification;
@@ -492,6 +493,11 @@ public class VerificationController {
               Tag.of(SCORE_TAG_NAME, assessmentResult.getScoreString())))
           .increment();
 
+      CaptchaMetrics.measureCaptchaOutcome(assessmentResult.getNormalizedIntScore(),
+          assessmentResult.isValid(captchaScoreThreshold),
+          Util.getRegion(registrationServiceSession.number()),
+          "verification");
+
     } catch (final IOException e) {
       logger.error("error assessing captcha during registration verification", e);
       throw new ServerErrorException(Response.Status.SERVICE_UNAVAILABLE, e);
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/limits/RateLimitChallengeManager.java b/service/src/main/java/org/whispersystems/textsecuregcm/limits/RateLimitChallengeManager.java
index b7e41d59a..e66917e5f 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/limits/RateLimitChallengeManager.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/limits/RateLimitChallengeManager.java
@@ -14,8 +14,10 @@ import java.io.IOException;
 import java.util.List;
 import java.util.Optional;
 import org.whispersystems.textsecuregcm.captcha.Action;
+import org.whispersystems.textsecuregcm.captcha.AssessmentResult;
 import org.whispersystems.textsecuregcm.captcha.CaptchaChecker;
 import org.whispersystems.textsecuregcm.controllers.RateLimitExceededException;
+import org.whispersystems.textsecuregcm.metrics.CaptchaMetrics;
 import org.whispersystems.textsecuregcm.metrics.UserAgentTagUtil;
 import org.whispersystems.textsecuregcm.push.NotPushRegisteredException;
 import org.whispersystems.textsecuregcm.spam.ChallengeType;
@@ -61,13 +63,18 @@ public class RateLimitChallengeManager {
     }
   }
 
-  public boolean answerCaptchaChallenge(final Account account, final String captcha, final String mostRecentProxyIp,
-      final String userAgent, final Optional<Float> scoreThreshold)
-      throws RateLimitExceededException, IOException {
+  public boolean answerCaptchaChallenge(final Account account,
+      final String captcha,
+      final String mostRecentProxyIp,
+      final String userAgent,
+      final Optional<Float> scoreThreshold) throws RateLimitExceededException, IOException {
 
     rateLimiters.getCaptchaChallengeAttemptLimiter().validate(account.getUuid());
 
-    final boolean challengeSuccess = captchaChecker.verify(Optional.of(account.getUuid()), Action.CHALLENGE, captcha, mostRecentProxyIp, userAgent).isValid(scoreThreshold);
+    final AssessmentResult assessmentResult =
+        captchaChecker.verify(Optional.of(account.getUuid()), Action.CHALLENGE, captcha, mostRecentProxyIp, userAgent);
+
+    final boolean challengeSuccess = assessmentResult.isValid(scoreThreshold);
 
     final Tags tags = Tags.of(
         Tag.of(SOURCE_COUNTRY_TAG_NAME, Util.getCountryCode(account.getNumber())),
@@ -77,6 +84,13 @@ public class RateLimitChallengeManager {
 
     Metrics.counter(CAPTCHA_ATTEMPT_COUNTER_NAME, tags).increment();
 
+    CaptchaMetrics.measureCaptchaOutcome(assessmentResult.getNormalizedIntScore(),
+        challengeSuccess,
+        Util.getRegion(account.getNumber()),
+        // Note: currently all challenges are for message-sending, but if we add more use cases, we'll need to make the
+        // accept a context from callers rather than hard-coding it here
+        "sendMessage");
+
     if (challengeSuccess) {
       rateLimiters.getCaptchaChallengeSuccessLimiter().validate(account.getUuid());
       resetRateLimits(account, ChallengeType.CAPTCHA);