🛡️ Sentinel: [HIGH] hmac.compare_digest 예외 처리 및 DoS 취약점 수정

[seonghobae]

🚨 Severity: HIGH
💡 Vulnerability: hmac.compare_digest 함수에 비 ASCII 문자가 포함된 문자열이 전달될 경우 TypeError가 발생하여 500 서버 에러를 유발하는 처리되지 않은 예외 취약점이 존재합니다.
🎯 Impact: 공격자가 악의적으로 비 ASCII 문자가 포함된 X-API-Key 헤더를 전송하여 서비스를 중단시키거나 리소스를 소모하게 하는 DoS(서비스 거부) 공격을 수행할 수 있습니다.
🔧 Fix: 두 인자 모두 .encode('utf-8')를 사용하여 바이트 형식으로 인코딩한 후 비교하도록 수정하여 예외를 방지했습니다.
✅ Verification: pytest 테스트 스위트가 모두 통과하는지 확인하였고, 모의 환경에서 유니코드 헤더가 포함된 요청이 정상적으로 401을 반환하는 것을 검증했습니다.

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PR created automatically by Jules for task 1454767504914277086 started by @seonghobae

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📥 Commits

Reviewing files that changed from the base of the PR and between 5a92586 and 578b14a.

📒 Files selected for processing (2)

• .jules/sentinel.md
• saas_web.py

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[Copilot]

Pull request overview

This PR hardens the FastAPI API-key authentication middleware to avoid unhandled exceptions (500s) and potential DoS when hmac.compare_digest receives non-ASCII str header values, by comparing byte strings instead.

Changes:

• Encode X-API-Key and configured keys to bytes before calling hmac.compare_digest.
• Record the vulnerability and prevention guidance in .jules/sentinel.md.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
saas_web.py	Updates API key comparison to use byte-encoded inputs for hmac.compare_digest.
.jules/sentinel.md	Adds a Sentinel entry documenting the compare_digest non-ASCII exception/DoS class.

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[seonghobae]

Superseded by canonical PR #361, which contains the same Unicode-safe constant-time API-key comparison and extends the security boundary to registry-backed runtime credentials and bounded result retention. Closing this duplicate.

[google-labs-jules]

Superseded by canonical PR #361, which contains the same Unicode-safe constant-time API-key comparison and extends the security boundary to registry-backed runtime credentials and bounded result retention. Closing this duplicate.

Understood. Acknowledging that this work is now obsolete and stopping work on this task.