Opens the module of the algorithm and the mode to be used


(PHP 4 >= 4.0.2, PHP 5)

mcrypt_module_openOpens the module of the algorithm and the mode to be used

Описание

resource mcrypt_module_open ( string $algorithm , string $algorithm_directory , string $mode , string $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().

Список параметров

algorithm

Одна из констант MCRYPT_ciphername или название алгоритма в виде строки.

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

Одна из констант MCRYPT_MODE_modename, либо одна из следующих строк: "ecb", "cbc", "cfb", "ofb", "nofb" и "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).

Возвращаемые значения

Normally it returns an encryption descriptor, or FALSE on error.

Примеры

Пример #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.

Пример #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";
?>

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