Appendix 1

Signature Generation

Transaction Status Enquiry

Java

String sourceSystem = "mxx";
String jsonStr = "{"
    + "\"Email\":\"\","
    + "\"TxnID\":\"20230615155030POS\","
    + "\"sourceSystem\":\"mxx\","
    + "\"sequenceNo\":\"1\""
    + "}";

String message = sourceSystem + "\n" + jsonStr;

String path = KEYPAIR_DIR + "private_key.pem";

FileReader fileReader = new FileReader(path);
PEMParser pemParser = new PEMParser(fileReader);

PEMKeyPair pemKeyPair = (PEMKeyPair) pemParser.readObject();
byte[] encodedPrivateKey = pemKeyPair.getPrivateKeyInfo().getEncoded();

PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(encodedPrivateKey);

KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PrivateKey privateKey = keyFactory.generatePrivate(keySpec);

Signature privateSignature = Signature.getInstance("SHA256withRSA");
privateSignature.initSign(privateKey);
privateSignature.update(message.getBytes(StandardCharsets.UTF_8));

byte[] signature = privateSignature.sign();
String signatureStr = URLEncoder.encode(Base64.getEncoder().encodeToString(signature));

Node.js

const privateKeyPath = "private_key.pem";
const fetchPrivateKey = async (path) => {
    try {
        const response = await fetch(path);
        const privateKey = await response.text();
        return privateKey;
        catch (error) {}
    }
};

const privateKey = await fetchPrivateKey(privateKeyPath);
const rsaPrivateKey = forge.pki.privateKeyFromPem(privateKey);
const sourceSystem = 'mxx';

const request = {
    Email: '',
    TxnID: '06a8735d-aa4d-4d89-a453-508be0122119',
    sourceSystem: sourceSystem,
    sequenceNo: '1',

};

const jsonString = JSON.stringify(request);
const data = `{sourceSystem}\n${jsonString}`;

//encryption step
const privateKey = await fetchPrivateKey(privateKeyPath);
const rsaPrivateKey = forge.pki.privateKeyFromPem(privateKey);
const md = forge.md.sha256.create();
md.update(data, 'utf8');
const signature = rsaPrivateKey.sign(md);
const signedMessage = encodedURIComponent(forge.util.encode64(signature));

Python

private_key_path = r"...\"

with open(private_key_path, "rb") as f:
    private_key_data = f.read()

private_key = serialization.load_pem_private_key(private_key_data, password=None, backend=default_backend())
sourceSystem = "mxx"

request_data = OrderedDict()
request_data["Email"] = ""
request_data["TxnID"] = "06a8735d-aa4d-4d89-a453-508be0122119"
request_data["sourceSystem"] = sourceSystem
request_data["sequenceNo"] = "1"

json_output = json.dumps(request_data, separators=(",", ":"))
data = f"{sourceSystem}\n{json_output}"
signature = private_key.sign(
    data.encode('utf-8'),
    padding.PKCSv15(),
    hashes.SHA256()
)
encoded_signature = base64.b64encode(signature).decode('utf-8')
url_encoded_signature = urllib.parse.quote(encoded_signature, safe='')

request_data["signedMessage"] = url_encoded_signature

.Net

string sourceSystem = "mxx";

string jsonStr = "{"
    + "\"Email\":\"\","
    + "\"TxnID\":\"\","
    + "\"sourceSystem\":\"\","
    + "\"sequenceNo\":\"\""
    + "}";

using (RSA rsa = RSA.Create())
{
    //private key used to sign message
    var reader = System.IO.File.ReadAllText(@"E:\xaas_development\Business_Idea_MyXaas\EPFDemo\WebApplication3\wwwroot\key\mxx\mxx_keypair\private_key.pem");
    String data = sourceSystem +"\n"+ jsonStr;
    rsa.ImportFromPem(reader.ToCharArray());
    byte[] signature = rsa.SignData(Encoding.UTF8.GetBytes(data), HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
    bool verify = rsa.VerifyData(Encoding.UTF8.GetBytes(data), signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
    signedMessage = Uri.EscapeDataString(Convert.ToBase64String(signature));
}

PHP

$sourceSystem = "mxx";

$jsonString = '{'
    . '"Email":"",'
    . '"TxnID":"06a8735d-aa4d-4d89-a453-508be0122119",'
    . '"sourceSystem":"' . $sourceSystem . '",'
    . '"sequenceNo":"1"'
    . '}';

$data = $sourceSystem . "\n" . $jsonString;

$privateKey = file_get_contents('key/mxx/mxx_keypair/private_key.pem');

//Sign the data
$rsa = openssl_get_privatekey($privateKey);
openssl_sign($data, $signature, $rsa, OPENSSL_ALGO_SHA256);
$signedMessage = urlencode(base64_encode($signature));