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hash_hmac

PHP function Edit on GitHub ✎

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

Generate a keyed hash value using the HMAC method

Description

hash_hmac(string $algo, string $data, 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 and an `E_WARNING` message was emitted.
7.2.0	Usage of non-cryptographic hash functions (adler32, crc32, crc32b, fnv132, fnv1a32, fnv164, fnv1a64, joaat) was disabled.

Examples

hash_hmac() example

php

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

The above example will output:

output

9c5c42422b03f0ee32949920649445e417b2c634050833c5165704b825c2a53b