Summary:
When we generate account tokens for CSRF keys and email verification, one of the inputs we use is the user's password hash. Users won't always have a password hash, so this is a weak input to key generation. This also couples CSRF weirdly with auth concerns.
Instead, give users a dedicated secret for use in token generation which is used only for this purpose.
Test Plan:
- Ran upgrade scripts.
- Verified all users got new secrets.
- Created a new user.
- Verified they got a secret.
- Submitted CSRF'd forms, they worked.
- Adjusted the CSRF token and submitted CSRF'd forms, verified they don't work.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Differential Revision: https://secure.phabricator.com/D8748
