hash_hmac_file() – Generating a Keyed HMAC Hash of a File’s Contents

hash_hmac_file() generates a keyed HMAC hash of the contents of a given file using the specified algorithm and secret key.

Parameters

$algo – The name of the hash algorithm to use (e.g., "md5", "sha256", "haval160,4"). See hash_algos() for a list of supported algorithms.

$filename – The path to the file whose hash is to be computed; supports fopen wrappers.

$key – The secret key used for HMAC generation.

$raw_output (optional) – Set to true to return the raw binary digest; false (default) returns a lowercase hexadecimal string.

Return value

If $raw_output is true, the function returns the raw binary digest; otherwise it returns a lowercase hexadecimal string. If the specified algorithm is not supported, FALSE is returned.

Example

<?php
// Create a file to hash
file_put_contents('example.txt', 'The quick brown fox jumped over the lazy dog.');
// Compute HMAC MD5 hash with a secret key
echo hash_hmac_file('md5', 'example.txt', 'secret');
?>

Output

7eb2b5c37443418fc77c136dd20e859c