1 files changed, 303 insertions, 0 deletions
diff --git a/src/main/java/de/thedevstack/conversationsplus/crypto/OtrEngine.java b/src/main/java/de/thedevstack/conversationsplus/crypto/OtrEngine.java
new file mode 100644
index 00000000..dfb64eaf
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/crypto/OtrEngine.java
@@ -0,0 +1,303 @@
+package de.thedevstack.conversationsplus.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 de.thedevstack.conversationsplus.Config;
+import de.thedevstack.conversationsplus.entities.Account;
+import de.thedevstack.conversationsplus.entities.Conversation;
+import de.thedevstack.conversationsplus.services.XmppConnectionService;
+import de.thedevstack.conversationsplus.xmpp.chatstate.ChatState;
+import de.thedevstack.conversationsplus.xmpp.jid.InvalidJidException;
+import de.thedevstack.conversationsplus.xmpp.jid.Jid;
+import de.thedevstack.conversationsplus.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;
+	}
+
+}