From 8013a28c91b962f6c151c5bdbf2d6f09ac84d909 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Thu, 23 Jul 2026 21:16:30 +0000
Subject: [PATCH 1/2] Fix timing attack vulnerability in token validation

---
 .jules/sentinel.md        | 4 ++++
 src/cli/commands/serve.ts | 9 +++------
 2 files changed, 7 insertions(+), 6 deletions(-)
 create mode 100644 .jules/sentinel.md

diff --git a/.jules/sentinel.md b/.jules/sentinel.md
new file mode 100644
index 00000000..8e1efdd7
--- /dev/null
+++ b/.jules/sentinel.md
@@ -0,0 +1,4 @@
+## 2026-07-23 - Timing Attack Vulnerability in Token Validation
+**Vulnerability:** Short-circuiting token validation by checking length before `crypto.timingSafeEqual` leaks the secret's length.
+**Learning:** Simple string length comparisons and buffer conversions create a fast path that leaks secret lengths via timing differences, undermining the constant-time evaluation of `timingSafeEqual`.
+**Prevention:** Always hash both secrets to a fixed length (e.g., using `crypto.createHash('sha256')`) before comparison to ensure true constant-time evaluation.
diff --git a/src/cli/commands/serve.ts b/src/cli/commands/serve.ts
index 2c37293e..e20ec168 100644
--- a/src/cli/commands/serve.ts
+++ b/src/cli/commands/serve.ts
@@ -346,13 +346,10 @@ export async function handleServeCommand(_options: unknown, command: Command) {
 
           let isAuthenticated = false;
           if (scheme?.toLowerCase() === 'bearer' && token) {
-            const tokenBuffer = Buffer.from(token);
+            const tokenHash = crypto.createHash('sha256').update(token).digest();
             for (const authToken of authTokens) {
-              const authTokenBuffer = Buffer.from(authToken);
-              if (
-                tokenBuffer.length === authTokenBuffer.length &&
-                crypto.timingSafeEqual(tokenBuffer, authTokenBuffer)
-              ) {
+              const authTokenHash = crypto.createHash('sha256').update(authToken).digest();
+              if (crypto.timingSafeEqual(tokenHash, authTokenHash)) {
                 isAuthenticated = true;
                 break;
               }

From bc0f08d04c6e2a25a74468fe841d5584d81935c2 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Thu, 23 Jul 2026 21:19:58 +0000
Subject: [PATCH 2/2] Fix timing attack vulnerability in token validation

---
 tests/integration/prompt_templates.test.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tests/integration/prompt_templates.test.ts b/tests/integration/prompt_templates.test.ts
index 21905259..f1360d78 100644
--- a/tests/integration/prompt_templates.test.ts
+++ b/tests/integration/prompt_templates.test.ts
@@ -36,7 +36,9 @@ describe('Prompt templates', () => {
 
     expect(planSystem).toContain('You are SalmonLoop.');
     expect(patchSystem).toContain('You are PATCH, a phase-native diff compiler.');
-    expect(autopilotSystem).toContain('You are a senior software engineer running in "autopilot" mode.');
+    expect(autopilotSystem).toContain(
+      'You are a senior software engineer running in "autopilot" mode.',
+    );
     expect(answerSystem).toContain('You are a coding assistant in "answer" mode.');
     expect(researchSystem).toContain('You are a research assistant.');
   });