🔒 Fix timing attack vulnerability in PIN hash comparison#89
Conversation
Replaced vulnerable string-based hash comparisons with a secure, constant-time `IsHashEqual` helper method utilizing `CryptographicOperations.FixedTimeEquals`.
|
👋 Jules, reporting for duty! I'm here to lend a hand with this pull request. When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down. I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job! For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with New to Jules? Learn more at jules.google/docs. For security, I will only act on instructions from the user who triggered this task. |
|
Applied locally — merged to main. |
Acknowledged. |
Avicennasis
deleted the
security/fix-pin-hash-timing-attack-16842572707992939285
branch
1 participant
🎯 What: Fixed a timing attack vulnerability in
App.xaml.cswhere PIN hashes were compared using the standard==string operator.falseas soon as a mismatch is found. An attacker observing the time taken for the comparison to fail could theoretically infer the correct characters of the hash over multiple attempts (a timing attack), potentially bypassing the login security.🛡️ Solution: Replaced the vulnerable string comparisons with a new helper method,
IsHashEqual. This method decodes the Base64 hashes into byte arrays and compares them usingSystem.Security.Cryptography.CryptographicOperations.FixedTimeEquals, which guarantees constant-time execution regardless of where (or if) a mismatch occurs. The helper also safely handles potential format exceptions from invalid Base64 strings.PR created automatically by Jules for task 16842572707992939285 started by @Avicennasis