I have moved my website to a new hosting provider where my Sagepay Form v3 script which receives the encrypted response is now failing.
At the previous hosting provider the script was working (php version there was 5.5.9) and the new hosting offers a choice from 5.4 to 6. At the first hosting provider the php version for a long time earlier was 5.2 (or maybe it was 5.3) and when they finally enforced a change to 5.5 it wrecked a lot of things in my website scripts which resulted in a very difficult period trying to fix them, which I achieved in the end.
One of those things was that the decrypt failed, just like it is doing again now. In that case I eventually fixed it by changing the decrypt line from:
$Decoded = DHclassInFunc::decryptAes($crypt,$EncryptionPassword);
to:
$Decoded = DHclassInFunc::decryptAes(($_GET['crypt']),$EncryptionPassword);
I had tried many other variations but only this last one worked.
So now the problem is back and I am completely at a loss. I have tried all of the previous variations but nothing works. Also the various php versions on offer at my new host.
My (LONG) question on the previous occasion was also posted here: see Website to Sagepay submit encryption code was working but now fails after server php upgrade
Can anyone suggest why this is failing this time round and what I can do to fix it?
EDIT 14/12/18 More info after investigation plus I am including more explanation and the full code from the two relevant scripts ------------------------
I made no progress and the website orders have had to be manually managed while the Sagepay return was not working. Now I have a little time so I am trying again.
I have now found that if I remove this line (below) on the "completed.php" page (the url to which the Sagepay response is directed) the script does not hang; however it is because it is that line which causes a fatal error.
$Decoded = DHclassInFunc::decryptAes(($_GET['crypt']),$EncryptionPassword);
Without the line and the resultant error the scipt is able to move on and call the the following page ("return.php") which then displays payment result information to the customer and also does other actions (such as sending the full order detail to our local - not on the internet - database).
However with the line removed the crypt in the url is not processed and therefore there are no values in the result variables which the completed.php page forwards to the return.php page.
This means that the $status variable is empty; in the return.php page this is evaluated as an error and therefore the customer is shown a message which says that there was an error and that no payment was taken - which is incorrect.
The lack of a "success" status value also means that the order in the web mysql database is not flagged as confirmed.
I had tried many other variations of the line to no avail (although the one given here worked before the website was moved to a new host).
The line does of course invoke the function in the class "DHclassInFunc" which is located in the functions.php file.
I am enclosing below the active code from of the two files, completed.php and functions.php
As far as I can work out the root problem is that the line
$Decoded = DHclassInFunc::decryptAes(($_GET['crypt']),$EncryptionPassword);
does not receive any value in 'crypt' and so there is no string for the function.php decrypt routine to work on resulting in the fatal error when that function is called: "PHP Fatal error: Class 'SagepayApiException' not found in /redacted/redacted/redacted.com/www/redacted/protx/functions.php on line 208"
I have added a line in the functions.php code as below:
echo '$strIn' . " string in with @ should be here?";
in order to try to expose the value which is being passed to the function but it simple prints the name of the var, not the values from the url content which is in the address bar of the completed.php page when it receives the response from Sagepay - eg:
Regarding whether it might be a unicode / iso issue I can't see why this would result in an empty value in $strIn since this has not yet been processed at all, merely captured (or not?).
COMPLETED.php ---------------------
<?php
include "functions.php";
$Decoded = DHclassInFunc::decryptAes($_GET['crypt'],$EncryptionPassword);
$values = getToken($Decoded);
$VendorTxCode = $values['VendorTxCode'];
$Status = $values['Status'];
$VPSTxID = $values['VPSTxId'];
$TxAuthNo = $values['TxAuthNo'];
$AVSCV2 = $values['AVSCV2'];
$Amount = $values['Amount'];
// protocol 2.22 fields
$AddressResult = $values[ 'AddressResult' ];
$PostCodeResult = $values[ 'PostCodeResult' ];
$CV2Result = $values[ 'CV2Result' ];
$GiftAid = $values[ 'GiftAid' ];
$VBVSecureStatus = $values[ '3DSecureStatus' ];
$CAVV = $values[ 'CAVV' ];
// DH my all-in-one details var
$ResultDetails = $ResultDetails . "Vendor Code: " . $VendorTxCode . " - ";
$ResultDetails = $ResultDetails . "Status: " . $Status . " - ";
$ResultDetails = $ResultDetails . "VPS Transaction ID: " . $VPSTxID . " - ";
$ResultDetails = $ResultDetails . "Auth Num: " . $TxAuthNo . " - ";
$ResultDetails = $ResultDetails . "AVS / CV2 response: " . $TxAuthNo . " - ";
$ResultDetails = $ResultDetails . "Amount: " . $Amount . " - ";
$ResultDetails = $ResultDetails . "Address Result: " . $AddressResult . " - ";
$ResultDetails = $ResultDetails . "PostCode Result: " . $PostCodeResult . " - ";
$ResultDetails = $ResultDetails . "PostCode Result: " . $PostCodeResult . " - ";
$ResultDetails = $ResultDetails . "CV2 Result: " . $CV2Result . " - ";
$ResultDetails = $ResultDetails . "GiftAid Result: " . $GiftAid . " - ";
$ResultDetails = $ResultDetails . "3DSecure Status: " . $VBVSecureStatus . " - ";
$ResultDetails = $ResultDetails . "CAVV Result: " . $CAVV . " - ";
$FindHyphen = strpos($VendorTxCode,'-');
$LastIdChar = $FindHyphen;
$MyOrderID = substr($VendorTxCode,0,$LastIdChar);
$StatusSave = $Status;
echo ' <FORM METHOD="POST" FORM NAME="GoToReturn" ACTION="../MXKart/return.php">'."\n";
echo ' <input type="hidden" name="response_code" value= "';
echo $Status;
echo '">'."\n";
echo ' <input type="hidden" name="order_number" value= "';
echo $MyOrderID;
echo '">'."\n";
echo ' <input type="hidden" name="secretword" value= "';
echo $secret_word;
echo '">'."\n";
//echo addslashes($ResultDetails);
echo ' <input type="hidden" name="response_reason_text" value= "';
echo $ResultDetails;
echo '">'."\n";
echo ' <input type="hidden" name="amount" value= "';
echo $Amount;
echo '">'."\n";
echo ' <input type="hidden" name="force" value= "';
echo $VendorTxCode;
echo '">'."\n";
$msg = "<br><strong>Getting payment result.... </strong> <br><br><h2 style=\"color:green;\">PLEASE WAIT AT THIS PAGE - do not close the page or move on. <br>There can be a delay of up to a minute so please be patient.</h2>";
echo $msg."\n";
echo '</FORM>'."\n";
echo '<script language="javascript">'."\n";
echo 'document.forms[0].submit();'."\n";
echo '</script>'."\n";
?>
FUNCTIONS.php ---------------------
<?
$VendorName="redacted";
$EncryptionPassword="redacted"; // LIVE server destination
//************ NEW CRYPT STUFF COPIED FRON SAGEPAY KIT util.php
//DH added class definition as shown in stackoverflow page - trying to fix error when run, on line static private function etc
class DHclassInFunc{
/**
* PHP's mcrypt does not have built in PKCS5 Padding, so we use this.
*
* @param string $input The input string.
*
* @return string The string with padding.
*/
static protected function addPKCS5Padding($input)
{
$blockSize = 16;
$padd = "";
// Pad input to an even block size boundary.
$length = $blockSize - (strlen($input) % $blockSize);
for ($i = 1; $i <= $length; $i++)
{
$padd .= chr($length);
}
return $input . $padd;
}
/**
* Remove PKCS5 Padding from a string.
*
* @param string $input The decrypted string.
*
* @return string String without the padding.
* @throws SagepayApiException
*/
static protected function removePKCS5Padding($input)
{
$blockSize = 16;
$padChar = ord($input[strlen($input) - 1]);
/* Check for PadChar is less then Block size */
if ($padChar > $blockSize)
{
throw new SagepayApiException('Invalid encryption string');
}
/* Check by padding by character mask */
if (strspn($input, chr($padChar), strlen($input) - $padChar) != $padChar)
{
throw new SagepayApiException('Invalid encryption string');
}
$unpadded = substr($input, 0, (-1) * $padChar);
/* Chech result for printable characters */
if (preg_match('/[[:^print:]]/', $unpadded))
{
throw new SagepayApiException('Invalid encryption string');
}
return $unpadded;
}
/**
* Encrypt a string ready to send to SagePay using encryption key.
*
* @param string $string The unencrypyted string.
* @param string $key The encryption key.
*
* @return string The encrypted string.
*/
static public function encryptAes($string, $key)
{
// AES encryption, CBC blocking with PKCS5 padding then HEX encoding.
// Add PKCS5 padding to the text to be encypted.
$string = self::addPKCS5Padding($string);
// Perform encryption with PHP's MCRYPT module.
$crypt = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $string, MCRYPT_MODE_CBC, $key);
// Perform hex encoding and return.
return "@" . strtoupper(bin2hex($crypt));
}
/**
* Decode a returned string from SagePay.
*
* @param string $strIn The encrypted String.
* @param string $password The encyption password used to encrypt the string.
*
* @return string The unecrypted string.
* @throws SagepayApiException
*/
static public function decryptAes($strIn, $password)
{
echo '$strIn' . " string in with @ should be here?";
$strIn = htmlspecialchars($strIn, ENT_COMPAT,'utf-8', true);
// HEX decoding then AES decryption, CBC blocking with PKCS5 padding.
// Use initialization vector (IV) set from $str_encryption_password.
$strInitVector = $password;
// Remove the first char which is @ to flag this is AES encrypted and HEX decoding.
$hex = substr($strIn, 1);
// Throw exception if string is malformed
if (!preg_match('/^[0-9a-fA-F]+$/', $hex))
{
//DH added section to print result of decryption onto page for debugging
//$hex = "pseudo hex";
//echo "throw error at line 188";
// echo $hex;
throw new SagepayApiException('Invalid encryption string');
}
$strIn = pack('H*', $hex);
// Perform decryption with PHP's MCRYPT module.
$stringReturn = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $password, $strIn, MCRYPT_MODE_CBC, $strInitVector);
return self::removePKCS5Padding($string);
}
}
/* The getToken function. **
** NOTE: A function of convenience that extracts the value from the "name=value&name2=value2..." VSP reply string **
** Works even if one of the values is a URL containing the & or = signs. */
function getToken($thisString) {
// List the possible tokens
$Tokens = array(
"Status",
"StatusDetail",
"VendorTxCode",
"VPSTxId",
"TxAuthNo",
"Amount",
"AVSCV2",
"AddressResult",
"PostCodeResult",
"CV2Result",
"GiftAid",
"3DSecureStatus",
"CAVV" );
// Initialise arrays
$output = array();
$resultArray = array();
// Get the next token in the sequence
for ($i = count($Tokens)-1; $i >= 0 ; $i--){
// Find the position in the string
$start = strpos($thisString, $Tokens[$i]);
// If it's present
if ($start !== false){
// Record position and token name
$resultArray[$i]->start = $start;
$resultArray[$i]->token = $Tokens[$i];
}
}
// Sort in order of position
sort($resultArray);
// Go through the result array, getting the token values
for ($i = 0; $i<count($resultArray); $i++){
// Get the start point of the value
$valueStart = $resultArray[$i]->start + strlen($resultArray[$i]->token) + 1;
// Get the length of the value
if ($i==(count($resultArray)-1)) {
$output[$resultArray[$i]->token] = substr($thisString, $valueStart);
} else {
$valueLength = $resultArray[$i+1]->start - $resultArray[$i]->start - strlen($resultArray[$i]->token) - 2;
$output[$resultArray[$i]->token] = substr($thisString, $valueStart, $valueLength);
}
}
// Return the ouput array
return $output;
}
// Randomise based on time
function randomise() {
list($usec, $sec) = explode(' ', microtime());
return (float) $sec + ((float) $usec * 100000);
}
?>
I am much in need of help to fix the problem in respect of the code or whether I am making mistakes in how I try to expose the value of the seemingly empty string, and therefore jumping to the wrong conclusion.
EDIT TUESDAY 18/12/18 ---------------
I have made some progress in that I have discovered the reason that the $_GET in the page "completed.php" was not obtaining any value at all from the page url in the return reply sent by Sagepay.
It was because the hosting platform's default php server settings only accepted up to 512 characters in the url; I was was able to change this to 2000 characters (see later comments) which fixed part the problem; the fatal error was gone but the decrypt still failed. However I could now debug because the functions now had data to work with and I could trace values in different parts of the script.
Unfortunately I am now completely at a loss in understanding the debug outputs - because in the first place I don't understand the decrypt functions at all despite searching for help.
The output seems to be reasonable as far as the decrypt line
$hex = substr($strIn, 1);
in "functions.php" which yields the content of the incoming crypt after the "@" has been stripped off.
But once the script moves to the line
$strIn = pack('H*', $hex);
it goes wrong because the output if the variable content now is littered with 'garbage' characters. I don't understand how the 'pack' works but I assume that the characters should all remain readable and therefore this is an encoding problem.
Link to image of a screenshot of the characters
The characters which display as a question mark within a black diamond in the image linked to above seem to be some of these these -
e? g!xh)̓G]/|CՖ'#]Ws܀͝Y?Ig@uQ*ߎ@KѦ
when I capture the text with a quick select-and-copy and then pass into a text editor.
But I don't know if the garbage characters are confined to those which are inserted by the 'pack' function and therefore the encoding mismatch is limited to just the function, rather than being an overall encoding issue with the submission and return data to and from Sagepay.
Unfortunately I am pretty bemused after a long long process of messing (trying everything) with encodings since the website move to the new host, changing scripts, headers, explicit encoding statements, script file encodings, php.ini encoding declarations, Mysql database encodings etc from the old (largely) ISO to utf_8. Mostly just trying to get rid of anomalous characters which are actually visible to users on the website. Squish one and you get a different one in its place.
So now my head throbs at the thought of tracking down how to deal with this if it is purely a encoding problem. Sagepay has told me that Form 3 is compatible with unicode but I know that this is contradicted by other advice I have received, and indeed my own experience having been through previous php and sagepay version changes at my old hosting provider.
There is no way that the website and database fundamentals are going to get changed back to ISO but if it is the case that I have to somehow let Sagepay alone dine on ISO, how can I do this most easily - what are the essentials?
The submit to Sagepay works just fine under utf-8, but do I have to change this to submit in ISO before I can specify ISO for the return which is where the real problem lies? And how best to force this ISO anyway - just for Sagepay - given that encoding often seem not to 'stick', a battleground of web technologies influencing the encoding.
On the other hand it would be great if it was just the 'pack' function that's out of kilter; and if there is an easy way or place to fix that. Can anyone advise please.
