The size of the initialization vector (iv) will be returned in bytes NOT bits, something to keep in mind specially if the iv is passed together appended or prepended with the encrypted data for decryption
mcrypt_get_iv_size
(PHP 4 >= 4.0.2, PHP 5, PHP 7 < 7.2.0, PECL mcrypt >= 1.0.0)
mcrypt_get_iv_size — Returns the size of the IV belonging to a specific cipher/mode combination
Avertizare
Această funcție a fost ÎNVECHITĂ începând cu PHP 7.1.0 și ELIMINATĂ începând cu PHP 7.2.0. Utilizarea acestei funcții este foarte nerecomandată.
Descrierea
mcrypt_get_iv_size
( string
$cipher
, string $mode
) : int
Gets the size of the IV belonging to a specific
cipher/mode combination.
It is more useful to use the mcrypt_enc_get_iv_size() function as this uses the resource returned by mcrypt_module_open().
Parametri
-
cipher -
Una din constantele
MCRYPT_ciphernamesau denumirea algoritmului ca șir de caractere. -
mode -
Una din constantele
MCRYPT_MODE_modenamesau unul din șirurile de caractere: "ecb", "cbc", "cfb", "ofb", "nofb" sau "stream".The IV is ignored in ECB mode as this mode does not require it. You will need to have the same IV (think: starting point) both at encryption and decryption stages, otherwise your encryption will fail.
Valorile întoarse
Returns the size of the Initialization Vector (IV) in bytes. On error the
function returns false. If the IV is ignored in the specified cipher/mode
combination zero is returned.
Exemple
Example #1 mcrypt_get_iv_size() Example
<?php
echo mcrypt_get_iv_size(MCRYPT_CAST_256, MCRYPT_MODE_CFB) . "\n";
echo mcrypt_get_iv_size('des', 'ecb') . "\n";
?>
A se vedea și
- mcrypt_get_block_size() - Gets the block size of the specified cipher
- mcrypt_enc_get_iv_size() - Returns the size of the IV of the opened algorithm
- mcrypt_create_iv() - Creates an initialization vector (IV) from a random source
add a note
User Contributed Notes 1 note
Hernanibus ¶
8 years ago
