Java HmacSHA512

Question

I am trying to mimic the pseudocode as below in Java, but get a different result. Could anyone please advise what I have done wrong here? Very appreciated.

Pseudo code is telling me the resulting hash should be:

69H45OZkKcmR9LOszbajUUPGkGT8IqasGPAWqW/1stGC2Mex2qhIB6aDbuoy7eGfMsaZiU8Y0lO3mQxlsWNPrw==

whereas my code is giving:

2pIphF0hOqzHqMlGk8KRYGi+/3OPYg+CF9X+qRdGeUP+zHxXYFzdbX/W+8/LFkUt8Pn1M4lXnwg0pSjDz51F+Q==

Pseudo Code:

function hmac_512(msg, sec) {
    sec = Base64Decode(sec);
    result = hmac(msg, sec, sha512);
    return Base64Encode(result);
}

secret = "7pgj8Dm6";
message = "Test\0Message";

result = hmac_512(message, secret);
if (result == "69H45OZkKcmR9LOszbajUUPGkGT8IqasGPAWqW/1stGC2Mex2qhIB6aDbuoy7eGfMsaZiU8Y0lO3mQxlsWNPrw==")
    print("Success!");
else
    printf("Error: %s", result);
Java / Groovy
String sign(String base64Key, byte[] bytes) {
    Mac mac = Mac.getInstance("HmacSHA512");
    SecretKey secretKey = new SecretKeySpec(Base64.decode(base64Key.getBytes()), "HmacSHA512");
    mac.init(secretKey);
    mac.update(bytes);
    return Base64.encodeBytes(mac.doFinal()).trim();
}

def tonce = (new Date()).time*1000    
def postBody['tonce'] = tonce;
// put other parameters in postBody

String postBodyInJson = new Gson().toJson(postBody)
String path = 'api/3/receive'
String data = path + "\0" + postBodyInJson
String sign = sign(secret, data.getBytes())

My Code:

 private static String CreateToken(String message, String secretKey)
{
    message = "Test\\oMessage";
    secretKey = "7pgj8Dm6";
    String hash = "";
    try {    

        Mac sha512_HMAC = Mac.getInstance("HmacSHA512");
        SecretKeySpec secret_key = new SecretKeySpec(Base64.decodeBase64(secretKey), "HmacSHA512");
        sha512_HMAC.init(secret_key);
        sha512_HMAC.update(message.getBytes());

        hash = Base64.encodeBase64String(sha512_HMAC.doFinal()).trim();
        System.out.println(hash);

    }
    catch (Exception e){
        System.out.println("Error");
    }
    return hash;
}

I think the message is not the same `\\o` and ``\0` is different — Hamuel, Aug 23 '17 at 15:39
Thanks Hamuel, that was exactly the problem! I appreciate it — Daniel Kim, Aug 23 '17 at 23:23

score 0 · Answer 1 · answered Aug 31 '20 at 00:20

this code run for me

public String getHmacSha512(String postData) {
    Mac sha512_HMAC;
    String result = "";

    try {
        byte[] byteKey = Constantes.PUBLIC_KEY.getBytes("UTF-8");
        final String HMAC_SHA512 = "HmacSHA512";
        sha512_HMAC = Mac.getInstance(HMAC_SHA512);
        SecretKeySpec keySpec = new SecretKeySpec(byteKey, HMAC_SHA512);
        sha512_HMAC.init(keySpec);

        byte[] mac_data = sha512_HMAC.doFinal(postData.getBytes("UTF-8"));
        result = bytesToHex(mac_data);

    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (NoSuchAlgorithmException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (InvalidKeyException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } finally {
        // System.out.println("Done");
    }
    return result;

}


 public String bytesToHex(byte[] bytes) {
    final char[] hexArray = "0123456789ABCDEF".toCharArray();
    char[] hexChars = new char[bytes.length * 2];
    for (int j = 0; j < bytes.length; j++) {
        int v = bytes[j] & 0xFF;
        hexChars[j * 2] = hexArray[v >>> 4];
        hexChars[j * 2 + 1] = hexArray[v & 0x0F];
    }
    return new String(hexChars);
}

Java HmacSHA512

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