README

A generic HMAC function that can be used with any hash

Install

composer install lyoshenka/php-hmac

Use

<?php
require __DIR__.'/vendor/autoload.php';

# Ensure that your hash functions returns raw output (not hex)
$sha256Fn = function($message) { return hash('sha256', $message, true); };

# Look up the block size - https://en.wikipedia.org/wiki/Comparison_of_cryptographic_hash_functions
$blockSize = 64; // make sure this in bytes, not bits

# Compute the HMAC digest
$digest = \lyoshenka\hmac("The message text goes here", "secret-key", $sha256Fn, $blockSize);

# Output the digest as a hex string
echo bin2hex($digest) . "\n";

Examples

See examples.php

References

• https://tools.ietf.org/html/rfc2104
• https://en.wikipedia.org/wiki/Hash-based_message_authentication_code
• https://en.wikipedia.org/wiki/Comparison_of_cryptographic_hash_functions