mcrypt_enc_get_iv_size

(PHP 4 >= 4.0.2, PHP 5, PHP 7)

mcrypt_enc_get_iv_size — Returns the size of the IV of the opened algorithm

Description

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.

Parameters

td: The encryption descriptor.

Return Values

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