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package eu.siacs.conversations.crypto;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.DSAPrivateKeySpec;
import java.security.spec.DSAPublicKeySpec;
import java.security.spec.InvalidKeySpecException;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
import eu.siacs.conversations.Config;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.services.XmppConnectionService;
import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
import net.java.otr4j.OtrEngineHost;
import net.java.otr4j.OtrException;
import net.java.otr4j.OtrPolicy;
import net.java.otr4j.OtrPolicyImpl;
import net.java.otr4j.session.InstanceTag;
import net.java.otr4j.session.SessionID;
public class OtrEngine implements OtrEngineHost {
private Account account;
private OtrPolicy otrPolicy;
private KeyPair keyPair;
private XmppConnectionService mXmppConnectionService;
public OtrEngine(XmppConnectionService service, Account account) {
this.account = account;
this.otrPolicy = new OtrPolicyImpl();
this.otrPolicy.setAllowV1(false);
this.otrPolicy.setAllowV2(true);
this.otrPolicy.setAllowV3(true);
this.keyPair = loadKey(account.getKeys());
this.mXmppConnectionService = service;
}
private KeyPair loadKey(JSONObject keys) {
if (keys == null) {
return null;
}
try {
BigInteger x = new BigInteger(keys.getString("otr_x"), 16);
BigInteger y = new BigInteger(keys.getString("otr_y"), 16);
BigInteger p = new BigInteger(keys.getString("otr_p"), 16);
BigInteger q = new BigInteger(keys.getString("otr_q"), 16);
BigInteger g = new BigInteger(keys.getString("otr_g"), 16);
KeyFactory keyFactory = KeyFactory.getInstance("DSA");
DSAPublicKeySpec pubKeySpec = new DSAPublicKeySpec(y, p, q, g);
DSAPrivateKeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
PublicKey publicKey = keyFactory.generatePublic(pubKeySpec);
PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
return new KeyPair(publicKey, privateKey);
} catch (JSONException e) {
return null;
} catch (NoSuchAlgorithmException e) {
return null;
} catch (InvalidKeySpecException e) {
return null;
}
}
private void saveKey() {
PublicKey publicKey = keyPair.getPublic();
PrivateKey privateKey = keyPair.getPrivate();
KeyFactory keyFactory;
try {
keyFactory = KeyFactory.getInstance("DSA");
DSAPrivateKeySpec privateKeySpec = keyFactory.getKeySpec(
privateKey, DSAPrivateKeySpec.class);
DSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(publicKey,
DSAPublicKeySpec.class);
this.account.setKey("otr_x", privateKeySpec.getX().toString(16));
this.account.setKey("otr_g", privateKeySpec.getG().toString(16));
this.account.setKey("otr_p", privateKeySpec.getP().toString(16));
this.account.setKey("otr_q", privateKeySpec.getQ().toString(16));
this.account.setKey("otr_y", publicKeySpec.getY().toString(16));
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
}
}
@Override
public void askForSecret(SessionID arg0, InstanceTag arg1, String arg2) {
// TODO Auto-generated method stub
}
@Override
public void finishedSessionMessage(SessionID arg0, String arg1)
throws OtrException {
}
@Override
public String getFallbackMessage(SessionID arg0) {
return "I would like to start a private (OTR encrypted) conversation but your client doesn’t seem to support that";
}
@Override
public byte[] getLocalFingerprintRaw(SessionID arg0) {
// TODO Auto-generated method stub
return null;
}
public PublicKey getPublicKey() {
if (this.keyPair == null) {
return null;
}
return this.keyPair.getPublic();
}
@Override
public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
if (this.keyPair == null) {
KeyPairGenerator kg;
try {
kg = KeyPairGenerator.getInstance("DSA");
this.keyPair = kg.genKeyPair();
this.saveKey();
mXmppConnectionService.databaseBackend.updateAccount(account);
} catch (NoSuchAlgorithmException e) {
Log.d(Config.LOGTAG,
"error generating key pair " + e.getMessage());
}
}
return this.keyPair;
}
@Override
public String getReplyForUnreadableMessage(SessionID arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public OtrPolicy getSessionPolicy(SessionID arg0) {
return otrPolicy;
}
@Override
public void injectMessage(SessionID session, String body)
throws OtrException {
MessagePacket packet = new MessagePacket();
packet.setFrom(account.getFullJid());
if (session.getUserID().isEmpty()) {
packet.setTo(session.getAccountID());
} else {
packet.setTo(session.getAccountID() + "/" + session.getUserID());
}
packet.setBody(body);
packet.addChild("private", "urn:xmpp:carbons:2");
packet.addChild("no-copy", "urn:xmpp:hints");
packet.setType(MessagePacket.TYPE_CHAT);
account.getXmppConnection().sendMessagePacket(packet);
}
@Override
public void messageFromAnotherInstanceReceived(SessionID id) {
Log.d(Config.LOGTAG,
"unreadable message received from " + id.getAccountID());
}
@Override
public void multipleInstancesDetected(SessionID arg0) {
// TODO Auto-generated method stub
}
@Override
public void requireEncryptedMessage(SessionID arg0, String arg1)
throws OtrException {
// TODO Auto-generated method stub
}
@Override
public void showError(SessionID arg0, String arg1) throws OtrException {
// TODO Auto-generated method stub
}
@Override
public void smpAborted(SessionID arg0) throws OtrException {
// TODO Auto-generated method stub
}
@Override
public void smpError(SessionID arg0, int arg1, boolean arg2)
throws OtrException {
throw new OtrException(new Exception("smp error"));
}
@Override
public void unencryptedMessageReceived(SessionID arg0, String arg1)
throws OtrException {
throw new OtrException(new Exception("unencrypted message received"));
}
@Override
public void unreadableMessageReceived(SessionID arg0) throws OtrException {
throw new OtrException(new Exception("unreadable message received"));
}
@Override
public void unverify(SessionID arg0, String arg1) {
// TODO Auto-generated method stub
}
@Override
public void verify(SessionID arg0, String arg1, boolean arg2) {
// TODO Auto-generated method stub
}
}
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