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.entities.Account;
21import eu.siacs.conversations.persistance.DatabaseBackend;
22import eu.siacs.conversations.xml.Element;
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 static final String LOGTAG = "xmppService";
35
36 private Account account;
37 private OtrPolicy otrPolicy;
38 private KeyPair keyPair;
39 private Context context;
40
41 public OtrEngine(Context context, Account account) {
42 this.account = account;
43 this.otrPolicy = new OtrPolicyImpl();
44 this.otrPolicy.setAllowV1(false);
45 this.otrPolicy.setAllowV2(true);
46 this.otrPolicy.setAllowV3(true);
47 this.keyPair = loadKey(account.getKeys());
48 }
49
50 private KeyPair loadKey(JSONObject keys) {
51 if (keys == null) {
52 return null;
53 }
54 try {
55 BigInteger x = new BigInteger(keys.getString("otr_x"),16);
56 BigInteger y = new BigInteger(keys.getString("otr_y"),16);
57 BigInteger p = new BigInteger(keys.getString("otr_p"),16);
58 BigInteger q = new BigInteger(keys.getString("otr_q"),16);
59 BigInteger g = new BigInteger(keys.getString("otr_g"),16);
60 KeyFactory keyFactory = KeyFactory.getInstance("DSA");
61 DSAPublicKeySpec pubKeySpec = new DSAPublicKeySpec(y, p, q, g);
62 DSAPrivateKeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
63 PublicKey publicKey = keyFactory.generatePublic(pubKeySpec);
64 PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
65 return new KeyPair(publicKey, privateKey);
66 } catch (JSONException e) {
67 return null;
68 } catch (NoSuchAlgorithmException e) {
69 return null;
70 } catch (InvalidKeySpecException e) {
71 return null;
72 }
73 }
74
75 private void saveKey() {
76 PublicKey publicKey = keyPair.getPublic();
77 PrivateKey privateKey = keyPair.getPrivate();
78 KeyFactory keyFactory;
79 try {
80 keyFactory = KeyFactory.getInstance("DSA");
81 DSAPrivateKeySpec privateKeySpec = keyFactory.getKeySpec(privateKey, DSAPrivateKeySpec.class);
82 DSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(publicKey, 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 return this.keyPair.getPublic();
123 }
124
125 @Override
126 public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
127 if (this.keyPair==null) {
128 KeyPairGenerator kg;
129 try {
130 kg = KeyPairGenerator.getInstance("DSA");
131 this.keyPair = kg.genKeyPair();
132 this.saveKey();
133 DatabaseBackend.getInstance(context).updateAccount(account);
134 } catch (NoSuchAlgorithmException e) {
135 Log.d(LOGTAG,"error generating key pair "+e.getMessage());
136 }
137 }
138 return this.keyPair;
139 }
140
141 @Override
142 public String getReplyForUnreadableMessage(SessionID arg0) {
143 // TODO Auto-generated method stub
144 return null;
145 }
146
147 @Override
148 public OtrPolicy getSessionPolicy(SessionID arg0) {
149 return otrPolicy;
150 }
151
152 @Override
153 public void injectMessage(SessionID session, String body) throws OtrException {
154 MessagePacket packet = new MessagePacket();
155 packet.setFrom(account.getFullJid()); //sender
156 packet.setTo(session.getAccountID()+"/"+session.getUserID()); //reciepient
157 packet.setBody(body);
158 Element privateTag = new Element("private");
159 privateTag.setAttribute("xmlns","urn:xmpp:carbons:2");
160 packet.addChild(privateTag);
161 packet.setType(MessagePacket.TYPE_CHAT);
162 account.getXmppConnection().sendMessagePacket(packet);
163 }
164
165 @Override
166 public void messageFromAnotherInstanceReceived(SessionID arg0) {
167 // TODO Auto-generated method stub
168
169 }
170
171 @Override
172 public void multipleInstancesDetected(SessionID arg0) {
173 // TODO Auto-generated method stub
174
175 }
176
177 @Override
178 public void requireEncryptedMessage(SessionID arg0, String arg1)
179 throws OtrException {
180 // TODO Auto-generated method stub
181
182 }
183
184 @Override
185 public void showError(SessionID arg0, String arg1) throws OtrException {
186 // TODO Auto-generated method stub
187
188 }
189
190 @Override
191 public void smpAborted(SessionID arg0) throws OtrException {
192 // TODO Auto-generated method stub
193
194 }
195
196 @Override
197 public void smpError(SessionID arg0, int arg1, boolean arg2)
198 throws OtrException {
199 // TODO Auto-generated method stub
200
201 }
202
203 @Override
204 public void unencryptedMessageReceived(SessionID arg0, String arg1)
205 throws OtrException {
206 // TODO Auto-generated method stub
207
208 }
209
210 @Override
211 public void unreadableMessageReceived(SessionID arg0) throws OtrException {
212 throw new OtrException(new Exception("unreadable message received"));
213 }
214
215 @Override
216 public void unverify(SessionID arg0, String arg1) {
217 // TODO Auto-generated method stub
218
219 }
220
221 @Override
222 public void verify(SessionID arg0, String arg1, boolean arg2) {
223 // TODO Auto-generated method stub
224
225 }
226
227}