Summary:
Ref T4398. We have several auth-related systems which require (or are improved by) the ability to hand out one-time codes which expire after a short period of time.
In particular, these are:
- SMS multi-factor: we need to be able to hand out one-time codes for this in order to prove the user has the phone.
- Password reset emails: we use a time-based rotating token right now, but we could improve this with a one-time token, so once you reset your password the link is dead.
- TOTP auth: we don't need to verify/invalidate keys, but can improve security by doing so.
This adds a generic one-time code storage table, and strengthens the TOTP enrollment process by using it. Specifically, you can no longer edit the enrollment form (the one with a QR code) to force your own key as the TOTP key: only keys Phabricator generated are accepted. This has no practical security impact, but generally helps raise the barrier potential attackers face.
Followup changes will use this for reset emails, then implement SMS multi-factor.
Test Plan:
- Enrolled in TOTP multi-factor auth.
- Submitted an error in the form, saw the same key presented.
- Edited the form with web tools to provide a different key, saw it reject and the server generate an alternate.
- Change the expiration to 5 seconds instead of 1 hour, submitted the form over and over again, saw it cycle the key after 5 seconds.
- Looked at the database and saw the tokens I expected.
- Ran the GC and saw all the 5-second expiry tokens get cleaned up.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T4398
Differential Revision: https://secure.phabricator.com/D9217
Summary:
Ref T3720. Ref T4310. Currently, we limit the maximum number of concurrent sessions of each type. This is primarily because sessions predate garbage collection and we had no way to prevent the session table from growing fairly quickly and without bound unless we did this.
Now that we have GC (and it's modular!) we can just expire unused sessions after a while and throw them away:
- Add a `sessionExpires` column to the table, with a key.
- Add a GC for old sessions.
- When we establish a session, set `sessionExpires` to the current time plus the session TTL.
- When a user uses a session and has used up more than 20% of the time on it, extend the session.
In addition to this, we could also rotate sessions, but I think that provides very little value. If we do want to implement it, we should hold it until after T3720 / T4310.
Test Plan:
- Ran schema changes.
- Looked at database.
- Tested GC:
- Started GC.
- Set expires on one row to the past.
- Restarted GC.
- Verified GC nuked the session.
- Logged in.
- Logged out.
- Ran Conduit method.
- Tested refresh:
- Set threshold to 0.0001% instead of 20%.
- Loaded page.
- Saw a session extension ever few page loads.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T4310, T3720
Differential Revision: https://secure.phabricator.com/D7976
