Manual:Hooks/UserCryptPassword

Details
Return false to implement your own hashing method.


 * &$password: String of the plaintext password to encrypt
 * &$salt: String of the password salt or Boolean false if no salt is provided
 * &$wgPasswordSalt: Boolean of whether the salt is used in the default hashing method
 * &$hash: If the hook returns false, this String will be used as the hash