(PHP 5 >= 5.1.2, PECL hash >= 1.1)
hash_hmac — Generate a keyed hash value using the HMAC method
Name of selected hashing algorithm (i.e. "md5", "sha256", "haval160,4", etc..)
Message to be hashed.
Shared secret key used for generating the HMAC variant of the message digest.
When set to TRUE, outputs raw binary data. Default value (FALSE) outputs lowercase hexits.
Returns a string containing the calculated message digest as lowercase hexits unless raw_output is set to true in which case the raw binary representation of the message digest is returned.
Example #1 hash_hmac() example
<?php
echo hash_hmac('ripemd160', 'The quick brown fox jumped over the lazy dog.', 'secret');
?>
上例将输出：
b8e7ae12510bdfb1812e463a7f086122cf37e4f7