(TIL) PSQL: Salt And Hash A Password With pgcrypto

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The pgcrypto extension that ships with PostgreSQL can be used to do a number of interesting things. This includes functions for doing salted password hashing. Using the crypt and gen_salt functions, we can securely store a user password and later compare it to plain-text passwords for authentication purposes.

create extension pgcrypto;

select crypt('pa$$w0rd', gen_salt('bf'));
                            crypt
--------------------------------------------------------------
 $2a$06$Z7wmrkYMOyLboLcULUYzNe6nHUcWywSZTt6nSrT5Xdv/VLdJ4g99K

> select (
    '$2a$06$Z7wmrkYMOyLboLcULUYzNe6nHUcWywSZTt6nSrT5Xdv/VLdJ4g99K' =
    crypt(
      'pa$$w0rd',
      '$2a$06$Z7wmrkYMOyLboLcULUYzNe6nHUcWywSZTt6nSrT5Xdv/VLdJ4g99K'
    )
  ) as matched;
 matched
---------
 t

> select (
    '$2a$06$Z7wmrkYMOyLboLcULUYzNe6nHUcWywSZTt6nSrT5Xdv/VLdJ4g99K' =
    crypt(
      'password',
      '$2a$06$Z7wmrkYMOyLboLcULUYzNe6nHUcWywSZTt6nSrT5Xdv/VLdJ4g99K'
    )
  ) as matched;
 matched
---------
 f

The salt value is generated using the blowfish encryption algorithm (hence, the 'bf'). There is support for other algorithms such as md5.

See the pgcrypt documentation for more details.

Via jbranchaud/til.

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