1package eu.siacs.conversations.crypto;
2
3import java.math.BigInteger;
4import java.security.KeyFactory;
5import java.security.KeyPair;
6import java.security.KeyPairGenerator;
7import java.security.NoSuchAlgorithmException;
8import java.security.PrivateKey;
9import java.security.PublicKey;
10import java.security.spec.DSAPrivateKeySpec;
11import java.security.spec.DSAPublicKeySpec;
12import java.security.spec.InvalidKeySpecException;
13
14import org.json.JSONException;
15import org.json.JSONObject;
16
17import android.content.Context;
18import android.util.Log;
19
20import eu.siacs.conversations.Config;
21import eu.siacs.conversations.entities.Account;
22import eu.siacs.conversations.persistance.DatabaseBackend;
23import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
24
25import net.java.otr4j.OtrEngineHost;
26import net.java.otr4j.OtrException;
27import net.java.otr4j.OtrPolicy;
28import net.java.otr4j.OtrPolicyImpl;
29import net.java.otr4j.session.InstanceTag;
30import net.java.otr4j.session.SessionID;
31
32public class OtrEngine implements OtrEngineHost {
33
34 private Account account;
35 private OtrPolicy otrPolicy;
36 private KeyPair keyPair;
37 private Context context;
38
39 public OtrEngine(Context context, Account account) {
40 this.account = account;
41 this.otrPolicy = new OtrPolicyImpl();
42 this.otrPolicy.setAllowV1(false);
43 this.otrPolicy.setAllowV2(true);
44 this.otrPolicy.setAllowV3(true);
45 this.keyPair = loadKey(account.getKeys());
46 }
47
48 private KeyPair loadKey(JSONObject keys) {
49 if (keys == null) {
50 return null;
51 }
52 try {
53 BigInteger x = new BigInteger(keys.getString("otr_x"), 16);
54 BigInteger y = new BigInteger(keys.getString("otr_y"), 16);
55 BigInteger p = new BigInteger(keys.getString("otr_p"), 16);
56 BigInteger q = new BigInteger(keys.getString("otr_q"), 16);
57 BigInteger g = new BigInteger(keys.getString("otr_g"), 16);
58 KeyFactory keyFactory = KeyFactory.getInstance("DSA");
59 DSAPublicKeySpec pubKeySpec = new DSAPublicKeySpec(y, p, q, g);
60 DSAPrivateKeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
61 PublicKey publicKey = keyFactory.generatePublic(pubKeySpec);
62 PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
63 return new KeyPair(publicKey, privateKey);
64 } catch (JSONException e) {
65 return null;
66 } catch (NoSuchAlgorithmException e) {
67 return null;
68 } catch (InvalidKeySpecException e) {
69 return null;
70 }
71 }
72
73 private void saveKey() {
74 PublicKey publicKey = keyPair.getPublic();
75 PrivateKey privateKey = keyPair.getPrivate();
76 KeyFactory keyFactory;
77 try {
78 keyFactory = KeyFactory.getInstance("DSA");
79 DSAPrivateKeySpec privateKeySpec = keyFactory.getKeySpec(
80 privateKey, DSAPrivateKeySpec.class);
81 DSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(publicKey,
82 DSAPublicKeySpec.class);
83 this.account.setKey("otr_x", privateKeySpec.getX().toString(16));
84 this.account.setKey("otr_g", privateKeySpec.getG().toString(16));
85 this.account.setKey("otr_p", privateKeySpec.getP().toString(16));
86 this.account.setKey("otr_q", privateKeySpec.getQ().toString(16));
87 this.account.setKey("otr_y", publicKeySpec.getY().toString(16));
88 } catch (NoSuchAlgorithmException e) {
89 e.printStackTrace();
90 } catch (InvalidKeySpecException e) {
91 e.printStackTrace();
92 }
93
94 }
95
96 @Override
97 public void askForSecret(SessionID arg0, InstanceTag arg1, String arg2) {
98 // TODO Auto-generated method stub
99
100 }
101
102 @Override
103 public void finishedSessionMessage(SessionID arg0, String arg1)
104 throws OtrException {
105 // TODO Auto-generated method stub
106
107 }
108
109 @Override
110 public String getFallbackMessage(SessionID arg0) {
111 // TODO Auto-generated method stub
112 return null;
113 }
114
115 @Override
116 public byte[] getLocalFingerprintRaw(SessionID arg0) {
117 // TODO Auto-generated method stub
118 return null;
119 }
120
121 public PublicKey getPublicKey() {
122 if (this.keyPair == null) {
123 return null;
124 }
125 return this.keyPair.getPublic();
126 }
127
128 @Override
129 public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
130 if (this.keyPair == null) {
131 KeyPairGenerator kg;
132 try {
133 kg = KeyPairGenerator.getInstance("DSA");
134 this.keyPair = kg.genKeyPair();
135 this.saveKey();
136 DatabaseBackend.getInstance(context).updateAccount(account);
137 } catch (NoSuchAlgorithmException e) {
138 Log.d(Config.LOGTAG,
139 "error generating key pair " + e.getMessage());
140 }
141 }
142 return this.keyPair;
143 }
144
145 @Override
146 public String getReplyForUnreadableMessage(SessionID arg0) {
147 // TODO Auto-generated method stub
148 return null;
149 }
150
151 @Override
152 public OtrPolicy getSessionPolicy(SessionID arg0) {
153 return otrPolicy;
154 }
155
156 @Override
157 public void injectMessage(SessionID session, String body)
158 throws OtrException {
159 MessagePacket packet = new MessagePacket();
160 packet.setFrom(account.getFullJid());
161 if (session.getUserID().isEmpty()) {
162 packet.setTo(session.getAccountID());
163 } else {
164 packet.setTo(session.getAccountID() + "/" + session.getUserID());
165 }
166 packet.setBody(body);
167 packet.addChild("private", "urn:xmpp:carbons:2");
168 packet.addChild("no-copy", "urn:xmpp:hints");
169 packet.setType(MessagePacket.TYPE_CHAT);
170 account.getXmppConnection().sendMessagePacket(packet);
171 }
172
173 @Override
174 public void messageFromAnotherInstanceReceived(SessionID arg0) {
175 // TODO Auto-generated method stub
176
177 }
178
179 @Override
180 public void multipleInstancesDetected(SessionID arg0) {
181 // TODO Auto-generated method stub
182
183 }
184
185 @Override
186 public void requireEncryptedMessage(SessionID arg0, String arg1)
187 throws OtrException {
188 // TODO Auto-generated method stub
189
190 }
191
192 @Override
193 public void showError(SessionID arg0, String arg1) throws OtrException {
194 // TODO Auto-generated method stub
195
196 }
197
198 @Override
199 public void smpAborted(SessionID arg0) throws OtrException {
200 // TODO Auto-generated method stub
201
202 }
203
204 @Override
205 public void smpError(SessionID arg0, int arg1, boolean arg2)
206 throws OtrException {
207 throw new OtrException(new Exception("smp error"));
208 }
209
210 @Override
211 public void unencryptedMessageReceived(SessionID arg0, String arg1)
212 throws OtrException {
213 throw new OtrException(new Exception("unencrypted message received"));
214 }
215
216 @Override
217 public void unreadableMessageReceived(SessionID arg0) throws OtrException {
218 throw new OtrException(new Exception("unreadable message received"));
219 }
220
221 @Override
222 public void unverify(SessionID arg0, String arg1) {
223 // TODO Auto-generated method stub
224
225 }
226
227 @Override
228 public void verify(SessionID arg0, String arg1, boolean arg2) {
229 // TODO Auto-generated method stub
230
231 }
232
233}