(PHP 4 >= 4.0.2, PHP 5)

mcrypt_get_iv_sizeReturns the size of the IV belonging to a specific cipher/mode combination


int mcrypt_get_iv_size ( string $cipher , string $mode )

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().



Una din constantele MCRYPT_ciphername sau denumirea algoritmului ca șir de caractere.


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.

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.


Example #1 mcrypt_get_iv_size() Example

echo mcrypt_get_iv_size(MCRYPT_CAST_256MCRYPT_MODE_CFB) . "\n";

mcrypt_get_iv_size('des''ecb') . "\n";

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