security-review-owasp-password-storage

Review password hashing by verifying the use of Argon2id, bcrypt, scrypt, or PBKDF2 with appropriate parameters. Check for unique salts, safe pepper separation, and correct input handling to ensure stored passwords can withstand offline cracking after a database breach.

Safe legacy password hash migration requires controlled rehash-on-login upgrade logic. Verify that the migration flow upgrades old hashes to modern algorithms like Argon2id or bcrypt without exposing credentials or weakening offline cracking resistance during the transition.

OWASP password storage guidance recommends safe pepper separation to protect hashes after a database breach. A pepper adds a server-side secret separate from the salt, but it must be stored securely outside the database to effectively increase offline cracking resistance.

Handling long passwords and Unicode truncation risks involves checking input handling before hashing. Verify the authentication flow does not silently truncate long passwords or normalize Unicode characters, ensuring consistent hashing behavior and preventing unexpected authentication failures.

PBKDF2 parameters meet OWASP password storage requirements when configured with appropriate work factors. Verify the iteration count is sufficiently high to resist offline cracking, ensuring the algorithm provides adequate protection for stored credentials against brute-force attacks.

Rehash-on-login upgrade logic needs a security review to verify controlled migration behavior. Flawed upgrade flows can expose credentials, weaken offline cracking resistance, or fail to properly transition legacy hashes to modern algorithms like Argon2id or bcrypt.