Implementing Session Timeout Enforcement in Mercurial

The server dropped the connection, and the code review died mid-commit. You check the logs. The culprit: a mercurial session that stayed alive far longer than security policy allowed. Session timeout enforcement isn’t just a checkbox on a compliance list. It’s a control point that decides who still has access and who doesn’t, down to the second.

Mercurial session timeout enforcement controls how long authenticated sessions remain valid before the system forces re-authentication. Without strict enforcement, stale sessions can be hijacked. With it, you reduce the attack window and keep repository integrity intact. The rule is simple: expired means dead. No exceptions.

Implementing session timeout in Mercurial requires pairing core server configs with authentication middleware. Start by defining a timeout duration that meets both security and workflow needs—short enough to limit exposure, long enough to avoid constant re-login friction. On the server side, enforce this in hgweb or in an HTTP reverse proxy with idle session tracking. Layer in token-based authentication with an explicit exp claim, so that even if HTTP state lingers, access tokens won’t.

For distributed teams, centralizing session control is critical. If you run Mercurial behind a load balancer, ensure that session state is stored in a single secure backend, not on individual nodes. Apply the timeout enforcement logic consistently across SSH and HTTP endpoints. Instruments like server hooks can assert remaining session lifetime at the start of any push or pull, blocking the operation if the threshold is breached.

Logging is part of enforcement. Every session expiration should be recorded with a timestamp, user ID, and client IP. Feed these into an audit pipeline to detect abnormal patterns—like multiple expirations from the same address in quick bursts, a classic indicator of brute-force or replay attempts.

Session timeout enforcement is not a set-and-forget mechanism. Review your values regularly. Update configs as threat models change. Tie re-authentication to multi-factor prompts for sensitive actions, and treat any expired session as a full stop, not a warning.

Mercurial runs fast, but security decisions must be faster. Build your timeout enforcement to react instantly, cut risks, and keep your repos locked down. If you want to see this kind of session security live—configured, tested, and deployed in minutes—check out hoop.dev and watch it run.