fix: replace self-keyed HMAC with AES-256-GCM for webhook secrets#2169
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Wachhund wants to merge 1 commit into
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fix: replace self-keyed HMAC with AES-256-GCM for webhook secrets#2169Wachhund wants to merge 1 commit into
Wachhund wants to merge 1 commit into
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The previous hashSecret() used createHmac('sha256', secret).update(secret)
where the HMAC key equals the input — degenerating to a reversible hash.
The processDelivery() fallback used the stored hash AS the signing key,
leaking it to webhook recipients.
Now encrypts webhook secrets with AES-256-GCM (same pattern as TOTP
secret storage) and decrypts on demand for signing.
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Summary
Fixes a cryptographic flaw in webhook secret storage:
hashSecret()usedcreateHmac('sha256', secret).update(secret)where the key equals the input, making it a deterministic hash reversible by brute force on DB leakprocessDelivery()fell back to using the stored hash value itself as the webhook signing key when the in-memory cache was cold, exposing it to recipientstotp.ts). Secrets are encrypted at rest and decrypted on demand for webhook signature generationTest plan
salt:iv:authTag:ciphertext)