mcrypt_enc_get_iv_size
PHP 4 >= 4.0.2, PHP 5, PHP 7 < 7.2.0, PECL mcrypt >= 1.0.0
mcrypt_enc_get_iv_size - Returns the size of the IV of the opened algorithm
Manual
mcrypt_enc_get_iv_size(
resource$td ): int
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.