Encrypt a file passing key and IV as hex strings
public static int FileEncrypt( string fileOut, string fileIn, string keyHex, Mode mode, string ivHex )
Public Shared Function FileEncrypt ( _ fileOut As String, _ fileIn As String, _ keyHex As String, _ mode As Mode, _ ivHex As String _ ) As Integer
0 if successful or non-zero error code
fileOut and fileIn must not be the same. The output file is in binary format.