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) { 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); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (JSONException e) { ConfigHelper.rescueJSONException(e); } catch(Exception e) { e.printStackTrace(); } } 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 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 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); } }