---
name: "Authen::Passphrase::MySQL41"
section: "3pm"
platform: "linux"
package: "libauthen-passphrase-perl"
version: "0.008-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Authen::Passphrase::MySQL41"
---

# Authen::Passphrase::MySQL41(3pm)

passphrases using the MySQL v4.1 algorithm

## NAME

Authen::Passphrase::MySQL41 - passphrases using the MySQL v4.1 algorithm

## SYNOPSIS

```
        use Authen::Passphrase::MySQL41;
        $ppr = Authen::Passphrase::MySQL41->new(
                hash_hex => "9CD12C48C4C5DD62914B".
                            "3FABB93131746E9E9115");
        $ppr = Authen::Passphrase::MySQL41->new(
                passphrase => "passphrase");
        $hash = $ppr->hash;
        $hash_hex = $ppr->hash_hex;
        if($ppr->match($passphrase)) { ...
```

## DESCRIPTION

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.

## CONSTRUCTOR

- Authen::Passphrase::MySQL41-\>new(ATTR =\> VALUE, ...)

  Generates a new passphrase recogniser object using the MySQL v4.1 algorithm.  The following attributes may be given:

  - **hash**

    The hash, as a string of 20 bytes.

  - **hash\_hex**

    The hash, as a string of 40 hexadecimal digits.

  - **passphrase**

    A passphrase that will be accepted.

  Either the hash or the passphrase must be given.

## METHODS

- $ppr-\>hash

  Returns the hash value, as a string of 20 bytes.

- $ppr-\>hash\_hex

  Returns the hash value, as a string of 40 uppercase hexadecimal digits.

- $ppr-\>match(PASSPHRASE)

  This method is part of the standard Authen::Passphrase interface.

## SEE ALSO

Authen::Passphrase, Digest::SHA

## AUTHOR

Andrew Main (Zefram) \<zefram@fysh.org\>

## COPYRIGHT

Copyright (C) 2006, 2007, 2009, 2010, 2012 Andrew Main (Zefram) \<zefram@fysh.org\>

## LICENSE

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