Appendix 1

Signature Verification

Pre-Authorization Payment

Java

String jsonStr = "{"
    + "\"sequenceNo\":\"1\","
    + "\"sourceSystem\":\"mxx\","
    + "\"MsgVer\":\"1.0\","
    + "\"TxnID\":\"20XX0825023XXXXX\","
    + "\"ResultCode\":\"0\","
    + "\"RespCd\":\"00\","
    + "\"OrgRespCd\":\"00\","
    + "\"RRN\":\"32376300XXXX\","
    + "\"STAN\":\"006XXX\","
    + "\"AuthIdResp\":\"945XXX\","
    + "\"MRN\":\"23237V6XXX\","
    + "\"TxnDTTime\":\"20230825143413\","
    + "\"PaymentScheme\":\"MC\""
    + "}";
byte[] messageBytes = jsonStr.getBytes();
signature.update(messageBytes);
boolean verified = signature.verify(signedMessageBytes);

Node.js

const request = {
    sequenceNo = '1',
	sourceSystem = 'mxx',
	MsgVer = '1.0',
	TxnID = '20230825023XXXXXX',
	ResultCode = '0',
	RespCd = '00',
	OrgRespCd = '00',
	RRN = '323763006XXX',
	STAN = '006XXX',
	AuthIdResp = '945XXX',
	MRN = '23237V6XXX',
	TxnDTTime = '20230825143413',
	PaymentScheme = 'MC'
};

const json = JSON.stringify(request);
const sourceSystem = "mxx";
const jsonString = `${sourceSystem}\n${json}`;
const signature = "68acc11449277468cb5e619f16bcff62f5448fa3911a462fd52abadaf4bc8f3effb";
const decodedUrl = decodeURIComponent(signature);
const decodedBytes = atob(decodedUrl);

const byteBuffer = new Uint8Array(decodedBytes.length);
for (let i = 0; i < decodedBytes.length; i++) {
    byteBuffer[i] = decodedBytes.charCodeAt(i);
}
const md = forge.md.sha256.create();
md.update(jsonString, "utf8");
const verified = rsaPubicKey.verify(md.digest().bytes(), byteBuffer);

Python

request_data = OrderedDict()
request_data["sequenceNo"] = "1"
request_data["sourceSystem"] = "mxx"
request_data["MsgVer"] = "1.0"
request_data["TxnID"] = "20230825023XXXXXX"
request_data["ResultCode"] = "0"
request_data["RespCd"] = "00"
request_data["OrgRespCd"] = "00"
request_data["RRN"] = "323763006XXX"
request_data["STAN"] = "006XXX"
request_data["AuthIdResp"] = "945XXX"
request_data["MRN"] = "23237V6XXX"
request_data["TxnDTTime"] = "20230825143413"
request_data["PaymentScheme"] = "MC"
json_string = json.dumps(request_data, separators=(",", ":"))
source_system="mxx"
message = f"{source_system}\n{json_string}"
signature = "68acc11449277468cb5e619f16bcff62f5448fa3911a462fd52abadaf4bc8f3effb"
verified = public_key.verify(
    signature,
    hasher.update(message).digest(),
    padding=padding,
)

.Net

string json = "{"
    + "\"sequenceNo\":\"1\","
    + "\"sourceSystem\":\"mxx\","
    + "\"MsgVer\":\"1.0\","
    + "\"TxnID\":\"20230825023XXXXXX\","
    + "\"ResultCode\":\"0\","
    + "\"RespCd\":\"00\","
    + "\"OrgRespCd\":\"00\","
    + "\"RRN\":\"323763006XXX\","
    + "\"STAN\":\"006XXX\","
    + "\"AuthIdResp\":\"945XXX\","
    + "\"MRN\":\"23237V6XXX\","
    + "\"TxnDTTime\":\"20230825143413\","
    + "\"PaymentScheme\":\"MC\""
    + "}";
string sourceSystem = "mxx";
string jsonString = sourceSystem + "\n" + json;
string signature = "68acc11449277468cb5e619f16bcff62f5448fa3911a462fd52abadaf4bc8f3effb";
bool verify = rsa.VerifyData(Encoding.UTF8.GetBytes(jsonString), Encoding.UTF8.GetBytes(signature), HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);

PHP

$jsonStringResponse = '{'
    . '"sequenceNo":"1",'
    . '"sourceSystem":"mxx",'
    . '"MsgVer":"1.0",'
    . '"TxnID":"20230825023XXXXXX",'
    . '"ResultCode":"0",'
    . '"RespCd":"00",'
    . '"OrgRespCd":"00",'
    . '"RRN":"323763006XXX",'
    . '"STAN":"006XXX",'
    . '"AuthIdResp":"945XXX",'
    . '"MRN":"23237V6XXX",'
    . '"TxnDTTime":"20230825143413",'
    . '"PaymentScheme":"MC"'
    . '}';
$sourceSystem='mxx';
$dataResponse = $sourceSystem . "\n" . $jsonStringResponse;
$minifiedJson = json_encode(json_decode($updateJson));

$decodedSignedMessage = '68acc11449277468cb5e619f16bcff62f5448fa3911a462fd52abadaf4bc8f3effb';
$decodedUrl = urldecode($decodedSignedMessage);
$decodedSignature = base64_decode($decodedUrl);
$verifyResponse = openssl_verify($dataResponse, $decodedSignature, $publicKeyPEM, OPENSSL_ALGO_SHA256);