bittrex_signing.kt

// example for signed operation with Bittrex V1.1 API

// kotlin code
fun getBalances(key: String, secret: String, listener: Response.Listener<String>) {
    var url = "https://bittrex.com/api/v1.1/account/getbalances?apikey=API_KEY&nonce=NONCE"

    val ir = InternetRequests()

    url = url.replace("API_KEY".toRegex(), key)
    url = url.replace("NONCE".toRegex(), Utils.getNonce()) // 1

    ir.addHeader("apisign", InternetRequests.hmacDigest(url, secret)) // 2
 
    ir.executePost(url, listener)
}

// 1
fun getNonce(): String = (System.currentTimeMillis() / 1000).toString()

// 2
// hmacDigest is basically when you sign the message using the "HmacSHA512" as algo and the secret as key
// the secret key is used ONLY for signing the request. So, it does not have to be sent in requests.
private static String hmacDigest(String msg, String keyString, String algo) {
    String digest = null;
    try {
        SecretKeySpec key = new SecretKeySpec(
                (keyString).getBytes("UTF-8"), algo);
        Mac mac = Mac.getInstance(algo);
        mac.init(key);

        byte[] bytes = mac.doFinal(msg.getBytes("ASCII"));

        StringBuilder hash = new StringBuilder();
        for (byte aByte : bytes) {
            String hex = Integer.toHexString(0xFF & aByte);

            if (hex.length() == 1)
                hash.append('0');

            hash.append(hex);
        }

        digest = hash.toString();
    } catch (Exception e) {
        e.printStackTrace();
    }

    return digest;
}