GitLab stores user passwords in a hashed format, to prevent passwords from being visible.
GitLab uses the Devise authentication library, which handles the hashing of user passwords. Password hashes are created with the following attributes:
- Hashing: the bcrypt hashing function is used to generate the hash of the provided password. This is a strong, industry-standard cryptographic hashing function.
- Stretching: Password hashes are stretched to harden against brute-force attacks. GitLab uses a stretching factor of 10 by default.
- Salting: A cryptographic salt is added to each password to harden against pre-computed hash and dictionary attacks. Each salt is randomly generated for each password, so that no two passwords share a salt, to further increase security.