mcrypt_get_iv_size

mcrypt_get_iv_size

Returns 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 / combination. cipher``mode

It is more useful to use the function as this uses the resource returned by . mcrypt_enc_get_iv_size``mcrypt_module_open

cipher``modeThe 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.

Voorbeeld: Example

<?php
    echo mcrypt_get_iv_size(MCRYPT_CAST_256, MCRYPT_MODE_CFB) . "\n";

    echo mcrypt_get_iv_size('des', 'ecb') . "\n";
?>

mcrypt_get_block_size``mcrypt_enc_get_iv_size``mcrypt_create_iv