Relative redirect URLs are now normalized before validation. Paths
containing backslashes (including percent-encoded %5c) are rejected,
closing a bypass where /../\evil.com passed checks but http.Redirect
normalized to /\evil.com.
Reported by Fushuling and RacerZ.
Signed-off-by: Bryan Frimin <bryan@probo.com>
Previous entry leaned on filler ("close the door behind it", "what
people expect") and gave only a vague behavioural summary. Replace
it with the actual mechanism: which table is touched, the transaction
boundary, the asymmetry between change (preserves caller) and reset
(revokes all), and why the session middleware needs no change.
Also drop the em dash in the metadata line.
Signed-off-by: Bryan Frimin <bryan@getprobo.com>
