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<mcrypt_module_openmdecrypt_generic>
^Mcrypt FunctionsLast updated: Mon, 26 Oct 2026

mcrypt_module_self_test

(PHP 4 >= 4.0.2, PHP 5, PHP 7 < 7.2.0, PECL mcrypt >= 1.0.0)

mcrypt_module_self_test — This function runs a self test on the specified module

Warning

This function has been DEPRECATED as of PHP 7.1.0 and REMOVED as of PHP 7.2.0. Relying on this function is highly discouraged.

Description

function mcrypt_module_self_test(string $algorithm, string $lib_dir = ?): bool

This function runs the self test on the algorithm specified.

Parameters

algorithm

One of the MCRYPT_ciphername constants, or the name of the algorithm as string.

lib_dir

The optional lib_dir parameter can contain the location where the algorithm module is on the system.

Return Values

The function returns true if the self test succeeds, or false when it fails.

Examples

Example #1 mcrypt_module_self_test() example

<?php
var_dump(mcrypt_module_self_test(MCRYPT_RIJNDAEL_128)) . "\n";
var_dump(mcrypt_module_self_test(MCRYPT_BOGUS_CYPHER));
?>

The above example will output:

bool(true)
bool(false)

<mcrypt_module_openmdecrypt_generic>
^Mcrypt FunctionsLast updated: Mon, 26 Oct 2026