Password and OAuth token storage
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GitLab administrators can configure how passwords and OAuth tokens are stored.
Password storage
- PBKDF2+SHA512 introduced in GitLab 15.2 with flags named
pbkdf2_password_encryption
andpbkdf2_password_encryption_write
. Disabled by default.- Feature flags removed in GitLab 15.6 and PBKDF2+SHA512 was made available to all GitLab instances running in FIPS mode.
GitLab stores user passwords in a hashed format to prevent passwords from being stored as plain text.
GitLab uses the Devise authentication library to hash user passwords. Created password hashes have these attributes:
-
Hashing:
-
bcrypt: By default, the
bcrypt
hashing function is used to generate the hash of the provided password. This cryptographic hashing function is strong and industry-standard. -
PBKDF2+SHA512: PBKDF2+SHA512 is supported:
- In GitLab 15.2 to GitLab 15.5 when
pbkdf2_password_encryption
andpbkdf2_password_encryption_write
feature flags are enabled. - In GitLab 15.6 and later when FIPS mode is enabled (feature flags are not required).
- In GitLab 15.2 to GitLab 15.5 when
-
bcrypt: By default, the
- Stretching: Password hashes are stretched to harden against brute-force attacks. By default, GitLab uses a stretching factor of 10 for bcrypt and 20,000 for PBKDF2 + SHA512.
- Salting: A cryptographic salt is added to each password to harden against pre-computed hash and dictionary attacks. To increase security, each salt is randomly generated for each password, with no two passwords sharing a salt.
OAuth access token storage
- PBKDF2+SHA512 introduced in GitLab 15.3 with flag named
hash_oauth_tokens
.- Enabled by default in GitLab 15.5.
- Feature flag removed in GitLab 15.6.
OAuth access tokens are stored in the database in PBKDF2+SHA512 format. As with PBKDF2+SHA512 password storage, access token values are stretched 20,000 times to harden against brute-force attacks.