Trying to implement the foreign exchange rates API using x-pay-token. The HelloWorld examples works without issue but doing a POST to /forexrates/v2/foreignexchangerates fails with code 9159 - Token Validation Failed.
The request body {"initiatingPartyId": 1002,"rateProductCode": "B","destinationCurrencyCode": "826","sourceCurrencyCode": "840", "quoteIdRequired": true, "sourceAmount": "1.00"} works in Developer Center Playground
// Using HelloWorld as the starting point. Changed the resourcePath, requestBody and url
public void getRate(String fromCurrency, String toCurrencies) {
try {
String apiKey = "<api key>";
String sharedSecret = "<shared secret>";
String resourcePath = "v2/foreignexchangerates"; // excluding /forexrates/
String queryString = "apiKey=" + apiKey;
String requestBody = "{\"initiatingPartyId\": 1002,\"rateProductCode\": \"B\",\"destinationCurrencyCode\": \"826\",\"sourceCurrencyCode\": \"840\", \"quoteIdRequired\": true, \"sourceAmount\": \"1.00\"}";
URL url = new URL("https://sandbox.api.visa.com/forexrates/v2/foreignexchangerates?" + queryString);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setRequestProperty("Content-Type", "application/json");
con.setRequestProperty("Accept", "application/json");
// String xPayToken = generateXpaytoken(resourcePath + "?" + queryString, queryString, requestBody, sharedSecret);
String xPayToken = generateXpaytoken(resourcePath, queryString, requestBody, sharedSecret);
con.setRequestProperty("x-pay-token", xPayToken);
int status = con.getResponseCode();
System.out.println("Http Status: " + status);
BufferedReader in ;
if (status == 200) { in = new BufferedReader(new InputStreamReader(con.getInputStream()));
} else { in = new BufferedReader(new InputStreamReader(con.getErrorStream()));
System.out.println("Api Key-Shared Secret (X-Pay-Token) test failed");
}
String response;
StringBuffer content = new StringBuffer();
while ((response = in .readLine()) != null) {
content.append(response);
} in .close();
con.disconnect();
System.out.println(content.toString());
} catch (Exception e) {
throw new RuntimeException(e);
}
});
}
// This line down is a direct copy from https://developer.visa.com/pages/working-with-visa-apis/x-pay-token
public static String generateXpaytoken(String resourcePath, String queryString, String requestBody, String sharedSecret) throws SignatureException {
String timestamp = timeStamp();
String beforeHash = timestamp + resourcePath + queryString + requestBody;
String hash = hmacSha256Digest(beforeHash, sharedSecret);
String token = "xv2:" + timestamp + ":" + hash;
return token;
}
private static String timeStamp() {
return String.valueOf(System.currentTimeMillis()/ 1000L);
}
private static String hmacSha256Digest(String data, String sharedSecret) throws SignatureException {
return getDigest("HmacSHA256", sharedSecret, data, true);
}
private static String getDigest(String algorithm, String sharedSecret, String data, boolean toLower) throws SignatureException {
try {
Mac sha256HMAC = Mac.getInstance(algorithm);
SecretKeySpec secretKey = new SecretKeySpec(sharedSecret.getBytes(StandardCharsets.UTF_8), algorithm);
sha256HMAC.init(secretKey);
byte[] hashByte = sha256HMAC.doFinal(data.getBytes(StandardCharsets.UTF_8));
String hashString = toHex(hashByte);
return toLower ? hashString.toLowerCase() : hashString;
} catch (Exception e) {
throw new SignatureException(e);
}
}
private static String toHex(byte[] bytes) {
BigInteger bi = new BigInteger(1, bytes);
return String.format("%0" + (bytes.length << 1) + "X", bi);
}
