PHP 手册
Mcrypt 函数

mcrypt_enc_get_iv_size

(PHP 4 >= 4.0.2, PHP 5)

mcrypt_enc_get_iv_sizeReturns the size of the IV of the opened algorithm

说明

int mcrypt_enc_get_iv_size ( resource $td )

This function returns the size of the IV of the algorithm specified by the encryption descriptor in bytes. An IV is used in cbc, cfb and ofb modes, and in some algorithms in stream mode.

参数

td

The encryption descriptor.

返回值

Returns the size of the IV, or 0 if the IV is ignored by the algorithm.


Mcrypt 函数
PHP 手册