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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.entities.Conversation;
import eu.siacs.conversations.services.XmppConnectionService;
import eu.siacs.conversations.utils.CryptoHelper;
import eu.siacs.conversations.xmpp.chatstate.ChatState;
import eu.siacs.conversations.xmpp.jid.InvalidJidException;
import eu.siacs.conversations.xmpp.jid.Jid;
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.crypto.OtrCryptoEngineImpl;
import net.java.otr4j.crypto.OtrCryptoException;
import net.java.otr4j.session.InstanceTag;
import net.java.otr4j.session.SessionID;
import net.java.otr4j.session.FragmenterInstructions;
public class OtrEngine extends OtrCryptoEngineImpl 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 (final NoSuchAlgorithmException | InvalidKeySpecException e) {
e.printStackTrace();
}
}
@Override
public void askForSecret(SessionID id, InstanceTag instanceTag, String question) {
try {
final Jid jid = Jid.fromSessionID(id);
Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
if (conversation!=null) {
conversation.smp().hint = question;
conversation.smp().status = Conversation.Smp.STATUS_CONTACT_REQUESTED;
mXmppConnectionService.updateConversationUi();
}
} catch (InvalidJidException e) {
Log.d(Config.LOGTAG,account.getJid().toBareJid()+": smp in invalid session "+id.toString());
}
}
@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) {
try {
return getFingerprintRaw(getPublicKey());
} catch (OtrCryptoException e) {
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.getJid());
if (session.getUserID().isEmpty()) {
packet.setAttribute("to", session.getAccountID());
} else {
packet.setAttribute("to", session.getAccountID() + "/" + session.getUserID());
}
packet.setBody(body);
packet.addChild("private", "urn:xmpp:carbons:2");
packet.addChild("no-copy", "urn:xmpp:hints");
packet.addChild("no-store", "urn:xmpp:hints");
try {
Jid jid = Jid.fromSessionID(session);
Conversation conversation = mXmppConnectionService.find(account,jid);
if (conversation != null && conversation.setOutgoingChatState(Config.DEFAULT_CHATSTATE)) {
if (mXmppConnectionService.sendChatStates()) {
packet.addChild(ChatState.toElement(conversation.getOutgoingChatState()));
}
}
} catch (final InvalidJidException ignored) {
}
packet.setType(MessagePacket.TYPE_CHAT);
account.getXmppConnection().sendMessagePacket(packet);
}
@Override
public void messageFromAnotherInstanceReceived(SessionID session) {
try {
Jid jid = Jid.fromSessionID(session);
Conversation conversation = mXmppConnectionService.find(account, jid);
String id = conversation == null ? null : conversation.getLastReceivedOtrMessageId();
if (id != null) {
MessagePacket packet = mXmppConnectionService.getMessageGenerator().generateOtrError(jid,id);
packet.setFrom(account.getJid());
mXmppConnectionService.sendMessagePacket(account,packet);
Log.d(Config.LOGTAG,packet.toString());
Log.d(Config.LOGTAG,account.getJid().toBareJid().toString()+": unreadable OTR message in "+conversation.getName());
}
} catch (InvalidJidException e) {
return;
}
}
@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 {
Log.d(Config.LOGTAG,"show error");
}
@Override
public void smpAborted(SessionID id) throws OtrException {
setSmpStatus(id, Conversation.Smp.STATUS_NONE);
}
private void setSmpStatus(SessionID id, int status) {
try {
final Jid jid = Jid.fromSessionID(id);
Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
if (conversation!=null) {
conversation.smp().status = status;
mXmppConnectionService.updateConversationUi();
}
} catch (final InvalidJidException ignored) {
}
}
@Override
public void smpError(SessionID id, int arg1, boolean arg2)
throws OtrException {
setSmpStatus(id, Conversation.Smp.STATUS_NONE);
}
@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 {
Log.d(Config.LOGTAG,"unreadable message received");
throw new OtrException(new Exception("unreadable message received"));
}
@Override
public void unverify(SessionID id, String arg1) {
setSmpStatus(id, Conversation.Smp.STATUS_FAILED);
}
@Override
public void verify(SessionID id, String fingerprint, boolean approved) {
Log.d(Config.LOGTAG,"OtrEngine.verify("+id.toString()+","+fingerprint+","+String.valueOf(approved)+")");
try {
final Jid jid = Jid.fromSessionID(id);
Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
if (conversation!=null) {
if (approved) {
conversation.getContact().addOtrFingerprint(fingerprint);
}
conversation.smp().hint = null;
conversation.smp().status = Conversation.Smp.STATUS_VERIFIED;
mXmppConnectionService.updateConversationUi();
mXmppConnectionService.syncRosterToDisk(conversation.getAccount());
}
} catch (final InvalidJidException ignored) {
}
}
@Override
public FragmenterInstructions getFragmenterInstructions(SessionID sessionID) {
return null;
}
}
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