(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
This function has been DEPRECATED as of PHP 7.1.0. Relying on this function is highly discouraged.
$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().
cipher
Una din constantele MCRYPT_ciphername
sau denumirea algoritmului ca șir de caractere.
mode
Una din constantele MCRYPT_MODE_modename
sau 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.
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.
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";
?>