Enforce username rules on every account-creation path - #20
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phulin merged 1 commit intoAug 16, 2026
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oops meant to close the one on my fork |
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can your claude resolve the conflict please? |
Username format rules (2-20 chars, [a-zA-Z0-9_] only) were enforced only
by POST /api/auth/username/check, which is advisory. The four paths that
actually insert users — email registration completion, OAuth completion,
and native Apple/Google sign-in — ran only the profanity filter, so a
300-character username containing HTML, newlines, and unicode was
accepted and stored.
Usernames are rendered directly into push notification bodies
("${user.username} sent you an Oy!"), so a stored username is attacker
-controlled lock-screen copy for anyone who receives an Oy.
validateUsername in lib.ts is now the single gate: length, character set,
and profanity. normalizeUsername (previously dead code) trims and
lowercases, matching how usernames are stored and looked up. Both are
applied at each creation path, and the check endpoint now delegates to
the same function so advisory results match what creation accepts.
Also removes fetchUserByUsername, which had no callers.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PvpccXvmDzszQ1fCJnaChX
Co-authored-by: jackowayed <18899+jackowayed@users.noreply.github.com>
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Username format rules (2-20 chars, [a-zA-Z0-9_] only) were enforced only by POST /api/auth/username/check, which is advisory. The four paths that actually insert users — email registration completion, OAuth completion, and native Apple/Google sign-in — ran only the profanity filter, so a 300-character username containing HTML, newlines, and unicode was accepted and stored.
Usernames are rendered directly into push notification bodies ("${user.username} sent you an Oy!"), so a stored username is attacker -controlled lock-screen copy for anyone who receives an Oy.
validateUsername in lib.ts is now the single gate: length, character set, and profanity. normalizeUsername (previously dead code) trims and lowercases, matching how usernames are stored and looked up. Both are applied at each creation path, and the check endpoint now delegates to the same function so advisory results match what creation accepts.
Also removes fetchUserByUsername, which had no callers.
Claude-Session: https://claude.ai/code/session_01PvpccXvmDzszQ1fCJnaChX