Authen::Passphrase::MySQL41(3) passphrases using the MySQL v4.1 algorithm


use Authen::Passphrase::MySQL41;
$ppr = Authen::Passphrase::MySQL41->new(
hash_hex => "9CD12C48C4C5DD62914B".
$ppr = Authen::Passphrase::MySQL41->new(
passphrase => "passphrase");
$hash = $ppr->hash;
$hash_hex = $ppr->hash_hex;
if($ppr->match($passphrase)) { ...


An object of this class encapsulates a passphrase hashed using the algorithm used by MySQL from version 4.1. This is a subclass of Authen::Passphrase, and this document assumes that the reader is familiar with the documentation for that class.

The MySQL v4.1 hash scheme is based on the SHA-1 digest algorithm. The passphrase is first hashed using SHA-1, then the output of that stage is hashed using SHA-1 again. The final hash is the output of the second SHA-1. No salt is used.

In MySQL the hash is represented as a "*" followed by 40 uppercase hexadecimal digits.

The lack of salt is a weakness in this scheme. Salted SHA-1 is a better scheme; see Authen::Passphrase::SaltedDigest.


Authen::Passphrase::MySQL41->new(ATTR => VALUE, ...)
Generates a new passphrase recogniser object using the MySQL v4.1 algorithm. The following attributes may be given:
The hash, as a string of 20 bytes.
The hash, as a string of 40 hexadecimal digits.
A passphrase that will be accepted.

Either the hash or the passphrase must be given.


Returns the hash value, as a string of 20 bytes.
Returns the hash value, as a string of 40 uppercase hexadecimal digits.
This method is part of the standard Authen::Passphrase interface.


Andrew Main (Zefram) <[email protected]>


Copyright (C) 2006, 2007, 2009, 2010, 2012 Andrew Main (Zefram) <[email protected]>


This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.