From c86ccd4cc149fac274437068e1efa00fd8862f61 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Fri, 17 Jul 2026 21:26:58 +0000
Subject: [PATCH 1/2] =?UTF-8?q?=F0=9F=9B=A1=EF=B8=8F=20Sentinel:=20[CRITIC?=
 =?UTF-8?q?AL/HIGH]=20Fix=20timing=20attack=20vulnerability=20in=20token?=
 =?UTF-8?q?=20comparison?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .jules/sentinel.md        |  4 ++++
 src/cli/commands/serve.ts | 10 ++++------
 2 files changed, 8 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..cba49061
--- /dev/null
+++ b/.jules/sentinel.md
@@ -0,0 +1,4 @@
+## 2024-05-24 - Timing Attack Vulnerability in Token Comparison
+**Vulnerability:** Comparing sensitive tokens using `Buffer.length` check before `crypto.timingSafeEqual` or using regular `===`.
+**Learning:** `timingSafeEqual` prevents timing attacks, but wrapping it in an early-return check on string/buffer length re-introduces the vulnerability because the attacker can learn the exact length of the required secret by observing timing differences.
+**Prevention:** Instead of checking lengths, hash both user-provided input and the stored secret to a fixed length (e.g. using `crypto.createHash('sha256')`) and then securely compare the hashes.
diff --git a/src/cli/commands/serve.ts b/src/cli/commands/serve.ts
index 2c37293e..e1021df5 100644
--- a/src/cli/commands/serve.ts
+++ b/src/cli/commands/serve.ts
@@ -346,13 +346,11 @@ export async function handleServeCommand(_options: unknown, command: Command) {
 
           let isAuthenticated = false;
           if (scheme?.toLowerCase() === 'bearer' && token) {
-            const tokenBuffer = Buffer.from(token);
+            // Hash both tokens to a fixed length to prevent leaking length via timing differences
+            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 74795c16f27484db84d603b195ab7c5495d0cda7 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Fri, 17 Jul 2026 21:33:08 +0000
Subject: [PATCH 2/2] =?UTF-8?q?=F0=9F=9B=A1=EF=B8=8F=20Sentinel:=20[CRITIC?=
 =?UTF-8?q?AL/HIGH]=20Fix=20timing=20attack=20vulnerability=20in=20token?=
 =?UTF-8?q?=20comparison?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 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.');
   });