1package de.gultsch.chat.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 de.gultsch.chat.entities.Account;
21import de.gultsch.chat.persistance.DatabaseBackend;
22import de.gultsch.chat.xml.Element;
23import de.gultsch.chat.xmpp.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 // TODO Auto-generated catch block
68 e.printStackTrace();
69 } catch (NoSuchAlgorithmException e) {
70 // TODO Auto-generated catch block
71 e.printStackTrace();
72 } catch (InvalidKeySpecException e) {
73 // TODO Auto-generated catch block
74 e.printStackTrace();
75 }
76 return null;
77 }
78
79 private void saveKey() {
80 PublicKey publicKey = keyPair.getPublic();
81 PrivateKey privateKey = keyPair.getPrivate();
82 KeyFactory keyFactory;
83 try {
84 keyFactory = KeyFactory.getInstance("DSA");
85 DSAPrivateKeySpec privateKeySpec = keyFactory.getKeySpec(privateKey, DSAPrivateKeySpec.class);
86 DSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(publicKey, DSAPublicKeySpec.class);
87 this.account.setKey("otr_x",privateKeySpec.getX().toString(16));
88 this.account.setKey("otr_g",privateKeySpec.getG().toString(16));
89 this.account.setKey("otr_p",privateKeySpec.getP().toString(16));
90 this.account.setKey("otr_q",privateKeySpec.getQ().toString(16));
91 this.account.setKey("otr_y",publicKeySpec.getY().toString(16));
92 } catch (NoSuchAlgorithmException e) {
93 e.printStackTrace();
94 } catch (InvalidKeySpecException e) {
95 e.printStackTrace();
96 } catch (JSONException e) {
97 e.printStackTrace();
98 }
99
100 }
101
102 @Override
103 public void askForSecret(SessionID arg0, InstanceTag arg1, String arg2) {
104 // TODO Auto-generated method stub
105
106 }
107
108 @Override
109 public void finishedSessionMessage(SessionID arg0, String arg1)
110 throws OtrException {
111 // TODO Auto-generated method stub
112
113 }
114
115 @Override
116 public String getFallbackMessage(SessionID arg0) {
117 // TODO Auto-generated method stub
118 return null;
119 }
120
121 @Override
122 public byte[] getLocalFingerprintRaw(SessionID arg0) {
123 // TODO Auto-generated method stub
124 return null;
125 }
126
127 public PublicKey getPublicKey() {
128 return this.keyPair.getPublic();
129 }
130
131 @Override
132 public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
133 if (this.keyPair==null) {
134 KeyPairGenerator kg;
135 try {
136 kg = KeyPairGenerator.getInstance("DSA");
137 this.keyPair = kg.genKeyPair();
138 this.saveKey();
139 DatabaseBackend.getInstance(context).updateAccount(account);
140 } catch (NoSuchAlgorithmException e) {
141 Log.d(LOGTAG,"error generating key pair "+e.getMessage());
142 }
143 }
144 return this.keyPair;
145 }
146
147 @Override
148 public String getReplyForUnreadableMessage(SessionID arg0) {
149 // TODO Auto-generated method stub
150 return null;
151 }
152
153 @Override
154 public OtrPolicy getSessionPolicy(SessionID arg0) {
155 return otrPolicy;
156 }
157
158 @Override
159 public void injectMessage(SessionID session, String body) throws OtrException {
160 MessagePacket packet = new MessagePacket();
161 packet.setFrom(account.getFullJid()); //sender
162 packet.setTo(session.getAccountID()+"/"+session.getUserID()); //reciepient
163 packet.setBody(body);
164 Element privateTag = new Element("private");
165 privateTag.setAttribute("xmlns","urn:xmpp:carbons:2");
166 packet.addChild(privateTag);
167 account.getXmppConnection().sendMessagePacket(packet);
168 }
169
170 @Override
171 public void messageFromAnotherInstanceReceived(SessionID arg0) {
172 // TODO Auto-generated method stub
173
174 }
175
176 @Override
177 public void multipleInstancesDetected(SessionID arg0) {
178 // TODO Auto-generated method stub
179
180 }
181
182 @Override
183 public void requireEncryptedMessage(SessionID arg0, String arg1)
184 throws OtrException {
185 // TODO Auto-generated method stub
186
187 }
188
189 @Override
190 public void showError(SessionID arg0, String arg1) throws OtrException {
191 // TODO Auto-generated method stub
192
193 }
194
195 @Override
196 public void smpAborted(SessionID arg0) throws OtrException {
197 // TODO Auto-generated method stub
198
199 }
200
201 @Override
202 public void smpError(SessionID arg0, int arg1, boolean arg2)
203 throws OtrException {
204 // TODO Auto-generated method stub
205
206 }
207
208 @Override
209 public void unencryptedMessageReceived(SessionID arg0, String arg1)
210 throws OtrException {
211 // TODO Auto-generated method stub
212
213 }
214
215 @Override
216 public void unreadableMessageReceived(SessionID arg0) throws OtrException {
217 // TODO Auto-generated method stub
218
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}