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.util.Log;
18
19import eu.siacs.conversations.Config;
20import eu.siacs.conversations.entities.Account;
21import eu.siacs.conversations.services.XmppConnectionService;
22import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
23
24import net.java.otr4j.OtrEngineHost;
25import net.java.otr4j.OtrException;
26import net.java.otr4j.OtrPolicy;
27import net.java.otr4j.OtrPolicyImpl;
28import net.java.otr4j.session.InstanceTag;
29import net.java.otr4j.session.SessionID;
30
31public class OtrEngine implements OtrEngineHost {
32
33 private Account account;
34 private OtrPolicy otrPolicy;
35 private KeyPair keyPair;
36 private XmppConnectionService mXmppConnectionService;
37
38 public OtrEngine(XmppConnectionService service, Account account) {
39 this.account = account;
40 this.otrPolicy = new OtrPolicyImpl();
41 this.otrPolicy.setAllowV1(false);
42 this.otrPolicy.setAllowV2(true);
43 this.otrPolicy.setAllowV3(true);
44 this.keyPair = loadKey(account.getKeys());
45 this.mXmppConnectionService = service;
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
106 }
107
108 @Override
109 public String getFallbackMessage(SessionID arg0) {
110 return "I would like to start a private (OTR encrypted) conversation but your client doesn’t seem to support that";
111 }
112
113 @Override
114 public byte[] getLocalFingerprintRaw(SessionID arg0) {
115 // TODO Auto-generated method stub
116 return null;
117 }
118
119 public PublicKey getPublicKey() {
120 if (this.keyPair == null) {
121 return null;
122 }
123 return this.keyPair.getPublic();
124 }
125
126 @Override
127 public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
128 if (this.keyPair == null) {
129 KeyPairGenerator kg;
130 try {
131 kg = KeyPairGenerator.getInstance("DSA");
132 this.keyPair = kg.genKeyPair();
133 this.saveKey();
134 mXmppConnectionService.databaseBackend.updateAccount(account);
135 } catch (NoSuchAlgorithmException e) {
136 Log.d(Config.LOGTAG,
137 "error generating key pair " + e.getMessage());
138 }
139 }
140 return this.keyPair;
141 }
142
143 @Override
144 public String getReplyForUnreadableMessage(SessionID arg0) {
145 // TODO Auto-generated method stub
146 return null;
147 }
148
149 @Override
150 public OtrPolicy getSessionPolicy(SessionID arg0) {
151 return otrPolicy;
152 }
153
154 @Override
155 public void injectMessage(SessionID session, String body)
156 throws OtrException {
157 MessagePacket packet = new MessagePacket();
158 packet.setFrom(account.getFullJid());
159 if (session.getUserID().isEmpty()) {
160 packet.setTo(session.getAccountID());
161 } else {
162 packet.setTo(session.getAccountID() + "/" + session.getUserID());
163 }
164 packet.setBody(body);
165 packet.addChild("private", "urn:xmpp:carbons:2");
166 packet.addChild("no-copy", "urn:xmpp:hints");
167 packet.setType(MessagePacket.TYPE_CHAT);
168 account.getXmppConnection().sendMessagePacket(packet);
169 }
170
171 @Override
172 public void messageFromAnotherInstanceReceived(SessionID id) {
173 Log.d(Config.LOGTAG,
174 "unreadable message received from " + id.getAccountID());
175 }
176
177 @Override
178 public void multipleInstancesDetected(SessionID arg0) {
179 // TODO Auto-generated method stub
180
181 }
182
183 @Override
184 public void requireEncryptedMessage(SessionID arg0, String arg1)
185 throws OtrException {
186 // TODO Auto-generated method stub
187
188 }
189
190 @Override
191 public void showError(SessionID arg0, String arg1) throws OtrException {
192 // TODO Auto-generated method stub
193
194 }
195
196 @Override
197 public void smpAborted(SessionID arg0) throws OtrException {
198 // TODO Auto-generated method stub
199
200 }
201
202 @Override
203 public void smpError(SessionID arg0, int arg1, boolean arg2)
204 throws OtrException {
205 throw new OtrException(new Exception("smp error"));
206 }
207
208 @Override
209 public void unencryptedMessageReceived(SessionID arg0, String arg1)
210 throws OtrException {
211 throw new OtrException(new Exception("unencrypted message received"));
212 }
213
214 @Override
215 public void unreadableMessageReceived(SessionID arg0) throws OtrException {
216 throw new OtrException(new Exception("unreadable message received"));
217 }
218
219 @Override
220 public void unverify(SessionID arg0, String arg1) {
221 // TODO Auto-generated method stub
222
223 }
224
225 @Override
226 public void verify(SessionID arg0, String arg1, boolean arg2) {
227 // TODO Auto-generated method stub
228
229 }
230
231}