Authen...MySQL41(3pm)

💖 Authen...MySQL41 💖

okay bestie, so this is a page from the User Contributed Perl Documentation — you know, the lil manual you get for Authen::Passphrase::MySQL41 (it's a 3pm page, obviously 💅). Sit down, grab a strawberry 🍓, and let's get into it.

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✨ NAME ✨

Authen::Passphrase::MySQL41 — passphrases using the MySQL v4.1 algorithm. yes, that MySQL. the old-ish one. iconic behavior tbh.

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🌸 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)) { ...

look at that. two ways in, three ways out. we love a flexible object 🫶

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🦋 DESCRIPTION 🦋

so an object of this class is like a lil container that encapsulates a passphrase hashed using the algorithm MySQL has been using since version 4.1. she's a subclass of Authen::Passphrase, and ngl this doc just assumes you already know the Authen::Passphrase documentation. so go read that first, bestie, fr fr.

the MySQL v4.1 hash scheme? it's based on the SHA-1 digest algorithm. here's the tea: the passphrase gets hashed with SHA-1 first, and then the output of that stage gets hashed with SHA-1 again. the final hash is the output of the second SHA-1. and no salt. none. zero. nada. 💀

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

⚠️ okay so the lack of salt is a genuine weakness in this scheme. like, lowkey a security problem. salted SHA-1 is a better scheme — go look at Authen::Passphrase::SaltedDigest. protect yourself bestie 💜

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🎀 CONSTRUCTOR 🎀

• Authen::Passphrase::MySQL41->new(ATTR => VALUE, ...) — generates a brand new passphrase recogniser object using the MySQL v4.1 algorithm. slay. you can pass these attributes:
  • 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. not optional, she needs something to work with 🙈

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💅 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. uppercase!! the glow-up is in the caps ⭐
• $ppr->match(PASSPHRASE) — checks if that passphrase matches. heads up: this method is part of the standard Authen::Passphrase interface, so it's not a special MySQL-only thing — it's the ✨canonical✨ way in. iykyk.

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👀 SEE ALSO 👀

• Authen::Passphrase
• Digest::SHA

go read those too, they're the supporting cast and they ate 🔥

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👑 AUTHOR 👑

Andrew Main (Zefram) <zefram@fysh.org> — absolute legend, we stan.

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🌈 COPYRIGHT 🌈

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

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💖 LICENSE 💖

this module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. go wild, that's the whole vibe 🧚

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and that's the page!! a little perl v5.40.1 moment, dated 2026-05-06, and it's one of those Authen...MySQL41(3pm) situations — anyway bestie, hydrate, salt your hashes, and go forth and match 🫶✨