AWDwR Login Question

In the following code there is a comparison of the password stored in the database with the
password entered by the user. Since the salt is created by appending a random number, how come it
matches with what is stored in the database?

def self.authenticate(name, password)
user = self.find_by_name(name)
if user
expected_password = encrypted_password(password, user.salt)
if user.hashed_password != expected_password
user = nil
end
end
user

create_new_salt
self.hashed_password = User.encrypted_password(self.password, self.salt)
end
private
def self.encrypted_password(password, salt)
string_to_hash = password + "wibble" + salt # 'wibble' makes it harder to guess
Digest::SHA1.hexdigest(string_to_hash)
end
def create_new_salt
self.salt = self.object_id.to_s + rand.to_s
end
end

TIA.

The salt's created only the first time it's needed; after that, it's always
the same (note that it's stored in the user's record). So it's "random" to
anyone trying a dictionary attack, but perfectly deterministic to your
application.

Jay Levitt

The salt is stored in the user record when it is created.

Cheers

Dave