(PHP 4 >= 4.0.2, PHP 5, PHP 7 < 7.2.0, PECL mcrypt >= 1.0.0)
mcrypt_module_open — Opens the module of the algorithm and the mode to be used
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.
$algorithm
,$algorithm_directory
,$mode
,$mode_directory
This function opens the module of the algorithm and the mode to be used. The name of the algorithm is specified in algorithm, e.g. "twofish"
or is one of the MCRYPT_ciphername
constants. The module is closed by calling mcrypt_module_close().
algorithm
One of the MCRYPT_ciphername
constants, or the name of the algorithm as string.
algorithm_directory
The algorithm_directory
parameter is used to locate the encryption module. When you supply a directory name, it is used. When you set it to an empty string (""
), the value set by the mcrypt.algorithms_dir
php.ini directive is used. When it is not set, the default directory that is used is the one that was compiled into libmcrypt (usually /usr/local/lib/libmcrypt).
mode
One of the MCRYPT_MODE_modename
constants, or one of the following strings: "ecb", "cbc", "cfb", "ofb", "nofb" or "stream".
mode_directory
The mode_directory
parameter is used to locate the encryption module. When you supply a directory name, it is used. When you set it to an empty string (""
), the value set by the mcrypt.modes_dir
php.ini directive is used. When it is not set, the default directory that is used is the one that was compiled-in into libmcrypt (usually /usr/local/lib/libmcrypt).
Normally it returns an encryption descriptor, or false
on error.
Example #1 mcrypt_module_open() Examples
<?php
$td = mcrypt_module_open(MCRYPT_DES, '',
MCRYPT_MODE_ECB, '/usr/lib/mcrypt-modes');
$td = mcrypt_module_open('rijndael-256', '', 'ofb', '');
?>
The first line in the example above will try to open the DES
cipher from the default directory and the ECB
mode from the directory /usr/lib/mcrypt-modes. The second example uses strings as name for the cipher and mode, this only works when the extension is linked against libmcrypt 2.4.x or 2.5.x.
Example #2 Using mcrypt_module_open() in encryption
<?php
$td = mcrypt_module_open('rijndael-256', '', 'ofb', '');
$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_DEV_RANDOM);
$ks = mcrypt_enc_get_key_size($td);
$key = substr(md5('very secret key'), 0, $ks);
mcrypt_generic_init($td, $key, $iv);
$encrypted = mcrypt_generic($td, 'This is very important data');
mcrypt_generic_deinit($td);
mcrypt_generic_init($td, $key, $iv);
$decrypted = mdecrypt_generic($td, $encrypted);
mcrypt_generic_deinit($td);
mcrypt_module_close($td);
echo trim($decrypted) . "\n";
?>