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hash_hmac_file

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 and the contents of a given file

Description

hash_hmac_file(string $algo, string $filename, string $key, bool $binary = false): string|false

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.
filename: URL describing location of file to be hashed; Supports fopen wrappers.
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. Returns false if the file filename cannot be read.

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_file() example

php

<?php
/* Create a file to calculate hash of */
file_put_contents('example.txt', 'The quick brown fox jumped over the lazy dog.');

echo hash_hmac_file('sha256', 'example.txt', 'secret');
?>

The above example will output:

output

9c5c42422b03f0ee32949920649445e417b2c634050833c5165704b825c2a53b