PHP Manual
Hash Functions
Generate a keyed hash value using the HMAC method

hash_hmac

(PHP 5 >= 5.1.2, PHP 7, PHP 8, PECL hash >= 1.1)

hash_hmac — Generate a keyed hash value using the HMAC method

Description

hash_hmac(
    string $algo,
    string $data,
    #[\SensitiveParameter] string $key,
    bool $binary = false
): string

Parameters

algo

Name of selected hashing algorithm (e.g. "sha256"). For a list of supported algorithms see hash_hmac_algos().

Note:
Non-cryptographic hash functions are not allowed.

data

Message to be hashed.

key

Shared secret key used for generating the HMAC variant of the message digest.

binary

When set to true, outputs raw binary data. false outputs lowercase hexits.

Return Values

Returns a string containing the calculated message digest as lowercase hexits unless binary is set to true in which case the raw binary representation of the message digest is returned.

Errors/Exceptions

Throws a ValueError exception if algo is unknown or is a non-cryptographic hash function.

Changelog

Version	Description
8.0.0	Now throws a ValueError exception if `algo` is unknown or is a non-cryptographic hash function; previously, `false` was returned instead.
7.2.0	Usage of non-cryptographic hash functions (adler32, crc32, crc32b, fnv132, fnv1a32, fnv164, fnv1a64, joaat) was disabled.

Examples

Example #1 hash_hmac() example

<?php
echo hash_hmac('sha256', 'The quick brown fox jumped over the lazy dog.', 'secret');
?>

The above example will output:

9c5c42422b03f0ee32949920649445e417b2c634050833c5165704b825c2a53b