Sagepay Error - 3045 : The Currency field is missing - php

Question

Please do not mark it as duplicate. I have already gone through almost all the previous post for same issue, but was not able to tackle my error.
I am trying to upgrade the Sagepay Protocol from v2.23 to v3.00
I have also deployed PHP kit provided by Sagepay and getting the same error.
Below is the AES encryption I am using to make it compatible for v3.00 in my includes.php
Any guidance would be much appreciated.
<?
/* Base 64 Encoding function **
** PHP does it natively but just for consistency and ease of maintenance, let's declare our own function **/
function base64Encode($plain) {
// Initialise output variable
$output = "";
// Do encoding
$output = base64_encode($plain);
// Return the result
return $output;
}
/* Base 64 decoding function **
** PHP does it natively but just for consistency and ease of maintenance, let's declare our own function **/
function base64Decode($scrambled) {
// Initialise output variable
$output = "";
// Fix plus to space conversion issue
$scrambled = str_replace(" ","+",$scrambled);
// Do encoding
$output = base64_decode($scrambled);
// Return the result
return $output;
}
/* The SimpleXor encryption algorithm **
** NOTE: This is a placeholder really. Future releases of Form will use AES or TwoFish. Proper encryption **
** This simple function and the Base64 will deter script kiddies and prevent the "View Source" type tampering **
** It won't stop a half decent hacker though, but the most they could do is change the amount field to something **
** else, so provided the vendor checks the reports and compares amounts, there is no harm done. It's still **
** more secure than the other PSPs who don't both encrypting their forms at all */
function simpleXor($InString, $Key) {
// Initialise key array
$KeyList = array();
// Initialise out variable
$output = "";
// Convert $Key into array of ASCII values
for($i = 0; $i < strlen($Key); $i++){
$KeyList[$i] = ord(substr($Key, $i, 1));
}
// Step through string a character at a time
for($i = 0; $i < strlen($InString); $i++) {
// Get ASCII code from string, get ASCII code from key (loop through with MOD), XOR the two, get the character from the result
// % is MOD (modulus), ^ is XOR
$output.= chr(ord(substr($InString, $i, 1)) ^ ($KeyList[$i % strlen($Key)]));
}
// Return the result
return $output;
}
//** Wrapper function do encrypt an encode based on strEncryptionType setting **
function encryptAndEncode($strPost) {
global $strEncryptionType
,$strEncryptionPassword;
if ($strEncryptionType=="XOR")
{
//** XOR encryption with Base64 encoding **
return base64Encode(simpleXor($strPost,$strEncryptionPassword));
}
else
{
//** AES encryption, CBC blocking with PKCS5 padding then HEX encoding - DEFAULT **
//** use initialization vector (IV) set from $strEncryptionPassword
$strIV = $strEncryptionPassword;
//** add PKCS5 padding to the text to be encypted
$strPost = addPKCS5Padding($strPost);
//** perform encryption with PHP's MCRYPT module
$strCrypt = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $strEncryptionPassword, $strPost, MCRYPT_MODE_CBC, $strIV);
//** perform hex encoding and return
return "#" . bin2hex($strCrypt);
}
}
//** Wrapper function do decode then decrypt based on header of the encrypted field **
function decodeAndDecrypt($strPost) {
global $strEncryptionPassword;
if (substr($strPost,0,1)=="#")
{
//** HEX decoding then AES decryption, CBC blocking with PKCS5 padding - DEFAULT **
//** use initialization vector (IV) set from $strEncryptionPassword
$strIV = $strEncryptionPassword;
//** remove the first char which is # to flag this is AES encrypted
$strPost = substr($strPost,1);
//** HEX decoding
$strPost = pack('H*', $strPost);
//** perform decryption with PHP's MCRYPT module
return mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $strEncryptionPassword, $strPost, MCRYPT_MODE_CBC, $strIV);
}
else
{
//** Base 64 decoding plus XOR decryption **
return simpleXor(base64Decode($strPost),$strEncryptionPassword);
}
}
//** PHP's mcrypt does not have built in PKCS5 Padding, so we use this
function addPKCS5Padding($input)
{
$blocksize = 16;
$padding = "";
// Pad input to an even block size boundary
$padlength = $blocksize - (strlen($input) % $blocksize);
for($i = 1; $i <= $padlength; $i++) {
$padding .= chr($padlength);
}
return $input . $padding;
}
/*************
function pkcs5_pad($text, $blocksize)
{
$pad = $blocksize - (strlen($text) % $blocksize);
//echo "<br/>Padding:".str_repeat(chr($pad), $pad)."<";
return $text . str_repeat(chr($pad), $pad);
}
function encryptFieldData($input)
{
$key = "[mykey]";
$iv = $key;
$cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128, "", MCRYPT_MODE_CBC, "");
if (mcrypt_generic_init($cipher, $key, $iv) != -1)
{
$cipherText = mcrypt_generic($cipher,$input );
mcrypt_generic_deinit($cipher);
$enc = bin2hex($cipherText);
}
return $enc;
}
$str = "Currency=GBP";
$datapadded = pkcs5_pad($str,16);
$cryptpadded = "#" . encryptFieldData($datapadded);
*************************/
?>

Answer 1

The problem was with my server mcrypt PHP extension. It wasn't install/enable on the server. I must have consider this before making all test attempts.
Thank you all for the efforts towards my issue.

Answer 2

Have you checked your encryption password is correct? 3045 is the first error to be thrown if the password is wrong. This is not so nuts as it sounds - encryption passwords are different between test and live.....