I currently working on an implementation of the Kraken API for Java. I am using this sample code I found on http://pastebin.com/nHJDAbH8.
The general usage as described by Kraken (https://www.kraken.com/help/api) is:
API-Key= API key
API-Sign= Message signature using HMAC-SHA512 of
( URI path + SHA256( nonce + POST data ) )andbase64decoded secret API key
and
nonce= always increasing unsigned 64 bit integer
otp= two-factor password ( if two-factor enabled, otherwise not required )
however I am facing the following response:
{"error":["EAPI:Invalid key"]}
I already tried a couple of ways ( getting a new API, trying to change the sha256 methods, because I thought something is wrong with the way it is hashed )
So this is the code:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
public class KrakenClient {
protected static String key = "myAPIKey"; // API key
protected static String secret = "MySecret===="; // API secret
protected static String url = "api.kraken.com"; // API base URL
protected static String version = "0"; // API version
public static void main(String[] args) throws Exception {
queryPrivateMethod("Balance");
}
public static void queryPrivateMethod(String method) throws NoSuchAlgorithmException, IOException{
long nonce = System.currentTimeMillis();
String path = "/" + version + "/private/" + method; // The path like "/0/private/Balance"
String urlComp = "https://"+url+path; // The complete url like "https://api.kraken.com/0/private/Balance"
String postdata = "nonce="+nonce;
String sign = createSignature(nonce, path, postdata);
postConnection(urlComp, sign, postdata);
}
/**
* @param nonce
* @param path
* @param postdata
* @return
* @throws NoSuchAlgorithmException
* @throws IOException
*/
private static String createSignature(long nonce, String path,
String postdata) throws NoSuchAlgorithmException, IOException {
return hmac(path+sha256(nonce + postdata), new String(Base64.decodeBase64(secret)));
}
public static String sha256Hex(String text) throws NoSuchAlgorithmException, IOException{
return org.apache.commons.codec.digest.DigestUtils.sha256Hex(text);
}
public static byte[] sha256(String text) throws NoSuchAlgorithmException, UnsupportedEncodingException{
MessageDigest md = MessageDigest.getInstance("SHA-256");
md.update(text.getBytes());
byte[] digest = md.digest();
return digest;
}
public static void postConnection(String url1, String sign, String postData) throws IOException{
URL url = new URL( url1 );
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.addRequestProperty("API-Key", key);
connection.addRequestProperty("API-Sign", Base64.encodeBase64String(sign.getBytes()));
// connection.addRequestProperty("API-Sign", sign);
connection.addRequestProperty("User-Agent", "Mozilla/4.0");
connection.setRequestMethod( "POST" );
connection.setDoInput( true );
connection.setDoOutput( true );
connection.setUseCaches( false );
// connection.setRequestProperty( "Content-Type",
// "application/x-www-form-urlencoded" );
connection.setRequestProperty( "Content-Length", String.valueOf(postData.length()) );
OutputStreamWriter writer = new OutputStreamWriter( connection.getOutputStream() );
writer.write( postData );
writer.flush();
BufferedReader reader = new BufferedReader(
new InputStreamReader(connection.getInputStream()) );
for ( String line; (line = reader.readLine()) != null; )
{
System.out.println( line );
}
writer.close();
reader.close();
}
public static String hmac(String text, String secret){
Mac mac =null;
SecretKeySpec key = null;
// Create a new secret key
try {
key = new SecretKeySpec( secret.getBytes( "UTF-8"), "HmacSHA512" );
} catch( UnsupportedEncodingException uee) {
System.err.println( "Unsupported encoding exception: " + uee.toString());
return null;
}
// Create a new mac
try {
mac = Mac.getInstance( "HmacSHA512" );
} catch( NoSuchAlgorithmException nsae) {
System.err.println( "No such algorithm exception: " + nsae.toString());
return null;
}
// Init mac with key.
try {
mac.init( key);
} catch( InvalidKeyException ike) {
System.err.println( "Invalid key exception: " + ike.toString());
return null;
}
// Encode the text with the secret
try {
return new String( mac.doFinal(text.getBytes( "UTF-8")));
} catch( UnsupportedEncodingException uee) {
System.err.println( "Unsupported encoding exception: " + uee.toString());
return null;
}
}
}
Here is a working example:
static String key = "---myKey---";
static String secret = "---mySecret---";
String nonce, signature, data, path;
static String domain = "https://api.kraken.com";
void account_balance() {
nonce = String.valueOf(System.currentTimeMillis());
data = "nonce=" + nonce;
path = "/0/private/Balance";
calculateSignature();
String answer = post(domain + path, data);
// on empty accounts, returns {"error":[],"result":{}}
// this is a known Kraken bug
...
}
String post(String address, String output) {
String answer = "";
HttpsURLConnection c = null;
try {
URL u = new URL(address);
c = (HttpsURLConnection)u.openConnection();
c.setRequestMethod("POST");
c.setRequestProperty("API-Key", key);
c.setRequestProperty("API-Sign", signature);
c.setDoOutput(true);
DataOutputStream os = new DataOutputStream(c.getOutputStream());
os.writeBytes(output);
os.flush();
os.close();
BufferedReader br = null;
if(c.getResponseCode() >= 400) {
System.exit(1);
}
br = new BufferedReader(new InputStreamReader((c.getInputStream())));
String line;
while ((line = br.readLine()) != null)
answer += line;
} catch (Exception x) {
System.exit(1);
} finally {
c.disconnect();
}
return answer;
}
void calculateSignature() {
signature = "";
try {
MessageDigest md = MessageDigest.getInstance("SHA-256");
md.update((nonce + data).getBytes());
Mac mac = Mac.getInstance("HmacSHA512");
mac.init(new SecretKeySpec(Base64.decodeBase64(secret.getBytes()), "HmacSHA512"));
mac.update(path.getBytes());
signature = new String(Base64.encodeBase64(mac.doFinal(md.digest())));
} catch(Exception e) {}
return;
}