mcrypt_module_open
(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. Relying on this function is highly discouraged.
Description
$algorithm
, string $algorithm_directory
, string $mode
, string $mode_directory
) : resource
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().
Parameters
-
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).
Examples
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
/* Open the cipher */
$td = mcrypt_module_open('rijndael-256', '', 'ofb', '');
/* Create the IV and determine the keysize length, use MCRYPT_RAND
* on Windows instead */
$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_DEV_RANDOM);
$ks = mcrypt_enc_get_key_size($td);
/* Create key */
$key = substr(md5('very secret key'), 0, $ks);
/* Intialize encryption */
mcrypt_generic_init($td, $key, $iv);
/* Encrypt data */
$encrypted = mcrypt_generic($td, 'This is very important data');
/* Terminate encryption handler */
mcrypt_generic_deinit($td);
/* Initialize encryption module for decryption */
mcrypt_generic_init($td, $key, $iv);
/* Decrypt encrypted string */
$decrypted = mdecrypt_generic($td, $encrypted);
/* Terminate decryption handle and close module */
mcrypt_generic_deinit($td);
mcrypt_module_close($td);
/* Show string */
echo trim($decrypted) . "\n";
?>
See Also
- mcrypt_module_close() - Closes the mcrypt module
- mcrypt_generic() - This function encrypts data
- mdecrypt_generic() - Decrypts data
- mcrypt_generic_init() - This function initializes all buffers needed for encryption
- mcrypt_generic_deinit() - This function deinitializes an encryption module
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Document created the 30/01/2003, last modified the 26/10/2018
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