Salted and Hashed Passwords in Grails via the Crypto Plugin

I wanted to share this tidbit n how to do salted and hashed passwords in Grails. If you don’t know why you want to do this, read Never store passwords in a database!. More on salting is available at Wikipedia’s article on Password Cracking.

To be smarter about passwords than the Reddit developers, first install the Crypto plugin via: grails install-plugin crypto. More information on the Crypto plugin is available on the Grails website: Grails Crypto Plugin Documentation.

I tend to then structure the password part of my application user class to look something like this:

import static cr.co.arquetipos.password.PasswordTools.*
 
class AppUser {
 
  static transients = ['password']
 
  String passwordHash
 
  boolean checkPassword(String password) {
    checkDigestBase64(password, passwordHash)
  }
 
  void setPassword(String password) {
    passwordHash = saltPasswordBase64(password)
  }
 
}

Once that’s done, you can execute code like this:

def user = new AppUser()
user.password = "foo"
assertTrue user.checkPassword("foo")

Note that this won’t work:

   assertEquals "foo", user.password // Fails because the 'password' property can't be found

Using this approach, the password is not stored in the database, or even in a transient property in the domain object. This minimizes the tendency to do something stupid (like e-mail the password in cleartext).