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package se.leap.leapclient;
import java.io.IOException;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.List;
import java.util.Random;
import java.util.Scanner;
import org.bouncycastle.crypto.CryptoException;
import org.bouncycastle.crypto.agreement.srp.SRP6Client;
import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.prng.RandomGenerator;
import org.bouncycastle.jcajce.provider.digest.Whirlpool.Digest;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import se.leap.leapclient.ProviderListContent.ProviderItem;
import android.app.IntentService;
import android.content.Intent;
import android.os.Bundle;
import android.os.ResultReceiver;
import android.util.Log;
public class ProviderAPI extends IntentService {
public ProviderAPI() {
super("ProviderAPI");
Log.v("ClassName", "Provider API");
// TODO Auto-generated constructor stub
}
@Override
protected void onHandleIntent(Intent task_for) {
final ResultReceiver receiver = task_for.getParcelableExtra("receiver");
Bundle task;
System.out.println("onHandleIntent called");
if((task = task_for.getBundleExtra(ConfigHelper.downloadJsonFilesBundleExtra)) != null) {
if(!downloadJsonFiles(task))
receiver.send(ConfigHelper.INCORRECTLY_DOWNLOADED_JSON_FILES, Bundle.EMPTY);
else
receiver.send(ConfigHelper.CORRECTLY_DOWNLOADED_JSON_FILES, Bundle.EMPTY);
}
else if ((task = task_for.getBundleExtra(ConfigHelper.downloadNewProviderDotJSON)) != null) {
boolean custom = true;
String provider_main_url = (String) task.get(ConfigHelper.provider_key_url);
String provider_name = provider_main_url.replaceFirst("http[s]?://", "").replaceFirst("\\/", "_");
String provider_json_url = guessURL(provider_main_url);
try {
JSONObject provider_json = getJSONFromProvider(provider_json_url);
String filename = provider_name + "_provider.json".replaceFirst("__", "_");
ConfigHelper.saveFile(filename, provider_json.toString());
ProviderListContent.addItem(new ProviderItem(provider_name, ConfigHelper.openFileInputStream(filename), custom));
receiver.send(ConfigHelper.CUSTOM_PROVIDER_ADDED, Bundle.EMPTY);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else if ((task = task_for.getBundleExtra(ConfigHelper.srpAuth)) != null) {
String username = "username";//(String) task.get(ConfigHelper.username_key);
String password = "password";//(String) task.get(ConfigHelper.password_key);
String authentication_server = "localhost:3000";//(String) task.get(ConfigHelper.srp_server_url_key);
SRP6Client srp_client = new SRP6Client();
srp_client.init(new BigInteger(ConfigHelper.NG_1024, 16), ConfigHelper.g, new SHA256Digest(), new SecureRandom());
// Receive salt from server
Random random_number_generator = new Random();
int salt = random_number_generator.nextInt(Integer.valueOf(ConfigHelper.NG_1024));
byte[] salt_in_bytes = ByteBuffer.allocate(4).putInt(salt).array();
BigInteger clientA = srp_client.generateClientCredentials(salt_in_bytes, username.getBytes(), password.getBytes());
//Send A to the server. Doing a http response with cookies?
//Receive server generated serverB
try {
BigInteger serverB = sendParameterToSRPServer(authentication_server, "A", clientA);
BigInteger s = srp_client.calculateSecret(serverB);
MessageDigest digest_of_S = MessageDigest.getInstance("SHA-256");
digest_of_S.update(s.toByteArray(), 0, s.toByteArray().length);
BigInteger k = new BigInteger(digest_of_S.digest());
BigInteger m1 = generateM1(k, clientA, serverB, salt, username);
BigInteger m2 = sendParameterToSRPServer(authentication_server, "M1", m1);
sendM1(m2, k, clientA, serverB, salt, username);
boolean verified = verifyM2(m2, k, clientA, serverB, salt, username);
if(!verified) {
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
// From sendAToSRPServer or from sendM1ToSRPServer
e.printStackTrace();
} catch (CryptoException e) {
// TODO Auto-generated catch block
// From calculateSecret
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
// From MessageDigest.getInstance
e.printStackTrace();
}
}
}
private boolean downloadJsonFiles(Bundle task) {
String cert_url = (String) task.get(ConfigHelper.cert_key);
String eip_service_json_url = (String) task.get(ConfigHelper.eip_service_key);
try {
String cert_string = getStringFromProvider(cert_url);
JSONObject cert_json = new JSONObject("{ \"certificate\" : \"" + cert_string + "\"}");
ConfigHelper.saveSharedPref(ConfigHelper.cert_key, cert_json);
JSONObject eip_service_json = getJSONFromProvider(eip_service_json_url);
ConfigHelper.saveSharedPref(ConfigHelper.eip_service_key, eip_service_json);
return true;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return false;
} catch (JSONException e) {
ConfigHelper.rescueJSONException(e);
return false;
} catch(Exception e) {
e.printStackTrace();
return false;
}
}
private void sendM1(BigInteger m2, BigInteger k, BigInteger clientA,
BigInteger serverB, int salt, String username) throws NoSuchAlgorithmException {
BigInteger M1 = generateM1(k, clientA, serverB, salt, username);
}
private BigInteger generateM1(BigInteger K, BigInteger clientA, BigInteger serverB, int salt, String username) throws NoSuchAlgorithmException {
/* https://github.com/leapcode/srp_js/blob/master/src/srp_session.js
var hashN = SHA256(hex2a(N.toString(16)))
var hashG = SHA256(hex2a(g.toString(16)))
var hexString = hexXor(hashN, hashG);
hexString += SHA256(I);
hexString += salt;
hexString += Astr;
hexString += Bstr;
hexString += K
M = SHA256(hex2a(hexString));
//M2 = H(A, M, K)
M2 = SHA256(hex2a(Astr + M + K));
*/
MessageDigest digest_of_N = MessageDigest.getInstance("SHA-256");
digest_of_N.update(ConfigHelper.NG_1024.getBytes());
String digest_of_N_as_string = new String(digest_of_N.digest());
MessageDigest digest_of_G = MessageDigest.getInstance("SHA-256");
digest_of_G.update(ConfigHelper.g.toByteArray());
String digest_of_G_as_string = new String(digest_of_G.digest());
String xor_n_and_g = hexXor(digest_of_N_as_string, digest_of_G_as_string);
MessageDigest digest_of_username = MessageDigest.getInstance("SHA-256");
digest_of_username.update(username.getBytes());
String digest_of_username_as_string = new String(digest_of_username.digest());
MessageDigest my_M1 = MessageDigest.getInstance("SHA-256");
String m1_source_string = xor_n_and_g + digest_of_username_as_string + clientA.toString() + serverB.toString() + K.toString();
my_M1.update(m1_source_string.getBytes());
return new BigInteger(my_M1.digest());
}
private boolean verifyM2(BigInteger M2, BigInteger K, BigInteger clientA, BigInteger serverB, int salt, String username) throws NoSuchAlgorithmException {
/* https://github.com/leapcode/srp_js/blob/master/src/srp_session.js
var hashN = SHA256(hex2a(N.toString(16)))
var hashG = SHA256(hex2a(g.toString(16)))
var hexString = hexXor(hashN, hashG);
hexString += SHA256(I);
hexString += salt;
hexString += Astr;
hexString += Bstr;
hexString += K
M = SHA256(hex2a(hexString));
//M2 = H(A, M, K)
M2 = SHA256(hex2a(Astr + M + K));
*/
MessageDigest digest_of_N = MessageDigest.getInstance("SHA-256");
digest_of_N.update(ConfigHelper.NG_1024.getBytes());
String digest_of_N_as_string = new String(digest_of_N.digest());
MessageDigest digest_of_G = MessageDigest.getInstance("SHA-256");
digest_of_G.update(ConfigHelper.g.toByteArray());
String digest_of_G_as_string = new String(digest_of_G.digest());
String xor_n_and_g = hexXor(digest_of_N_as_string, digest_of_G_as_string);
MessageDigest digest_of_username = MessageDigest.getInstance("SHA-256");
digest_of_username.update(username.getBytes());
String digest_of_username_as_string = new String(digest_of_username.digest());
MessageDigest my_M1 = MessageDigest.getInstance("SHA-256");
String m1_source_string = xor_n_and_g + digest_of_username_as_string + clientA.toString() + serverB.toString() + K.toString();
my_M1.update(m1_source_string.getBytes());
MessageDigest my_own_M2 = MessageDigest.getInstance("SHA-256");
String m2_source_string = clientA.toString() + new String(my_M1.digest()) + K.toString();
my_own_M2.update(m2_source_string.getBytes());
return M2 == new BigInteger(my_own_M2.digest());
}
private String hexXor(String a, String b) {
String str = "";
for (int i = 0; i < a.length(); i += 2) {
int xor = Integer.parseInt(a.substring(i, 2), 16) ^ Integer.parseInt(b.substring(i, 2), 16);
String xor_string = String.valueOf(Integer.valueOf(String.valueOf(xor), 16));
str += (xor_string.length() == 1) ? ("0" + xor) : xor_string;
}
return str;
}
private BigInteger sendParameterToSRPServer(String server_url, String parameter_name, BigInteger parameter) throws ClientProtocolException, IOException {
DefaultHttpClient client = new LeapHttpClient(getApplicationContext());
String parameter_chain = parameter_name + "=" + parameter.toString();
HttpPost post = new HttpPost(server_url + "?" + parameter_chain);
// TODO Look for how our srp server sends the serverB (as a cookie?) and how to fetch it from response.
HttpResponse getResponse = client.execute(post);
HttpEntity responseEntity = getResponse.getEntity();
List<Cookie> cookies = client.getCookieStore().getCookies();
return BigInteger.valueOf((Long.valueOf(cookies.get(0).getValue())));
}
private String guessURL(String provider_main_url) {
return provider_main_url + "/provider.json";
}
private String getStringFromProvider(String string_url) throws IOException {
String json_file_content = "";
DefaultHttpClient client = new LeapHttpClient(getApplicationContext());
HttpGet get = new HttpGet(string_url);
// Execute the GET call and obtain the response
HttpResponse getResponse = client.execute(get);
HttpEntity responseEntity = getResponse.getEntity();
json_file_content = new Scanner(responseEntity.getContent()).useDelimiter("\\A").next();
return json_file_content;
}
private JSONObject getJSONFromProvider(String json_url) throws IOException, JSONException {
String json_file_content = getStringFromProvider(json_url);
return new JSONObject(json_file_content);
}
}
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