Security context

Highlights

Denial of Service: 5 prior fixes. Scrutinize any change in this area.

oauth2: most-fixed (3 issues). Treat as high-risk during review.

2 high-severity fixes in this history; regressions here are high-impact.

Recurring patterns

Insecure Randomness: The generation of OAuth2 state parameters originally relied on a weak pseudorandom generator (math/rand) combined with low byte entropy, allowing attackers to predict state values and execute session fixation or CSRF attacks. Subsequent fixes swapped the generator for a cryptographically secure alternative and doubled the state token byte length.

Denial of Service: Concurrent access to user records and authentication hashes in the htpasswd file parser caused map write race conditions and subsequent program crashes. This required replacing package-level globals with fine-grained read/write mutexes bound directly to the authentication struct instances.

Denial of Service: A lack of validation on API responses from upstream OAuth providers caused nil pointer dereferences. Specifically, assuming a user profile always contains at least one email address (gu.Emails[0]) caused panics and crashes when encountering accounts without registered email addresses.