🛡️ Sentinel: [HIGH] Harden safeEqual against timing side-channel attacks#50
🛡️ Sentinel: [HIGH] Harden safeEqual against timing side-channel attacks#50SuvenSeo wants to merge 1 commit into
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Modified frontend/src/lib/middleware/auth.js to hash inputs with SHA-256 before constant-time comparison, neutralizing length-based timing leaks. Co-authored-by: SuvenSeo <263689617+SuvenSeo@users.noreply.github.com>
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Pull request overview
Hardens the safeEqual helper to eliminate a length-based timing side-channel by hashing both inputs with SHA-256 before performing the constant-time comparison, so the buffers passed to timingSafeEqual always have identical length regardless of input.
Changes:
- Replace length-check +
timingSafeEqual(Buffer.from(a), Buffer.from(b))withtimingSafeEqual(sha256(a), sha256(b)). - Add a Sentinel learning note documenting the vulnerability and the fix.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| frontend/src/lib/middleware/auth.js | Hash both inputs with SHA-256 before constant-time comparison to remove length leak. |
| .jules/sentinel.md | New Sentinel log entry documenting the timing side-channel vulnerability and prevention guidance. |
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🚨 Severity: HIGH
💡 Vulnerability: Timing side-channel attack in
safeEqualutility.🎯 Impact: An attacker could perform a timing attack to determine the length of secrets (DASHBOARD_PASSWORD, CRON_SECRET, etc.) and then proceed to brute-force or guess the values more efficiently.
🔧 Fix: Modified
safeEqualto hash both inputs with SHA-256 before constant-time comparison usingtimingSafeEqual. This ensures uniform buffer lengths and prevents length-based timing leaks.✅ Verification: Ran
npm testin thefrontenddirectory. All 34 tests (including auth and webhook verification tests that rely onsafeEqual) passed.PR created automatically by Jules for task 13090750406378637729 started by @SuvenSeo