(PHP 4 >= 4.0.2, PHP 5)
mcrypt_generic_init — This function initializes all buffers needed for encryption
( resource $td
, string $key
, string $iv
The encryption descriptor.
The maximum length of the key should be the one obtained by calling
mcrypt_enc_get_key_size() and every value smaller
than this is legal.
The IV should normally have the size of the algorithms block size, but
you must obtain the size by calling
mcrypt_enc_get_iv_size(). IV is ignored in ECB. IV
MUST exist in CFB, CBC, STREAM, nOFB and OFB modes. It needs to be
random and unique (but not secret). The same IV must be used for
encryption/decryption. If you do not want to use it you should set it
to zeros, but this is not recommended.
The function returns a negative value on error, -3 when the key length
was incorrect, -4 when there was a memory allocation problem and any
other return value is an unknown error. If an error occurs a warning will
be displayed accordingly. FALSE is returned if incorrect parameters