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comparison src/ch/ethz/ssh2/crypto/dh/DhExchange.java @ 273:91a31873c42a ganymed

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start conversion from trilead to ganymed
author Carl Byington <carl@five-ten-sg.com>
date Fri, 18 Jul 2014 11:21:46 -0700
parents
children 071eccdff8ea
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272:ce2f4e397703 273:91a31873c42a
1 /*
2 * Copyright (c) 2006-2013 Christian Plattner. All rights reserved.
3 * Please refer to the LICENSE.txt for licensing details.
4 */
5 package ch.ethz.ssh2.crypto.dh;
6
7 import java.io.IOException;
8 import java.math.BigInteger;
9 import java.security.SecureRandom;
10
11 import ch.ethz.ssh2.crypto.digest.HashForSSH2Types;
12 import ch.ethz.ssh2.log.Logger;
13 import ch.ethz.ssh2.util.StringEncoder;
14
15 /**
16 * @author Christian Plattner
17 * @version $Id: DhExchange.java 152 2014-04-28 11:02:23Z dkocher@sudo.ch $
18 */
19 public class DhExchange {
20 private static final Logger log = Logger.getLogger(DhExchange.class);
21
22 /* Given by the standard */
23
24 static final BigInteger p1, p14;
25 static final BigInteger g;
26
27 BigInteger p;
28
29 /* Client public and private */
30
31 BigInteger e;
32 BigInteger x;
33
34 /* Server public and private */
35
36 BigInteger f;
37 BigInteger y;
38
39 /* Shared secret */
40
41 BigInteger k;
42
43 static {
44 final String p1_string = "17976931348623159077083915679378745319786029604875"
45 + "60117064444236841971802161585193689478337958649255415021805654859805036464"
46 + "40548199239100050792877003355816639229553136239076508735759914822574862575"
47 + "00742530207744771258955095793777842444242661733472762929938766870920560605"
48 + "0270810842907692932019128194467627007";
49
50 final String p14_string = "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129"
51 + "024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0"
52 + "A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB"
53 + "6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A"
54 + "163BF0598DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208"
55 + "552BB9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36C"
56 + "E3BE39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF69558171"
57 + "83995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF";
58
59 p1 = new BigInteger(p1_string);
60 p14 = new BigInteger(p14_string, 16);
61 g = new BigInteger("2");
62 }
63
64 public DhExchange() {
65 }
66
67 public void clientInit(int group, SecureRandom rnd) {
68 k = null;
69
70 if(group == 1) {
71 p = p1;
72 }
73 else if(group == 14) {
74 p = p14;
75 }
76 else {
77 throw new IllegalArgumentException("Unknown DH group " + group);
78 }
79
80 while(true) {
81 x = new BigInteger(p.bitLength() - 1, rnd);
82 if(x.compareTo(BigInteger.ONE) > 0) {
83 break;
84 }
85 }
86
87 e = g.modPow(x, p);
88 }
89
90 public void serverInit(int group, SecureRandom rnd) {
91 k = null;
92
93 if(group == 1) {
94 p = p1;
95 }
96 else if(group == 14) {
97 p = p14;
98 }
99 else {
100 throw new IllegalArgumentException("Unknown DH group " + group);
101 }
102
103 y = new BigInteger(p.bitLength() - 1, rnd);
104
105 f = g.modPow(y, p);
106 }
107
108 /**
109 * @return Returns the e.
110 * @throws IllegalStateException
111 */
112 public BigInteger getE() {
113 if(e == null) {
114 throw new IllegalStateException("DhDsaExchange not initialized!");
115 }
116
117 return e;
118 }
119
120 /**
121 * @return Returns the f.
122 * @throws IllegalStateException
123 */
124 public BigInteger getF() {
125 if(f == null) {
126 throw new IllegalStateException("DhDsaExchange not initialized!");
127 }
128
129 return f;
130 }
131
132 /**
133 * @return Returns the shared secret k.
134 * @throws IllegalStateException
135 */
136 public BigInteger getK() {
137 if(k == null) {
138 throw new IllegalStateException("Shared secret not yet known, need f first!");
139 }
140
141 return k;
142 }
143
144 /**
145 * @param f
146 */
147 public void setF(BigInteger f) {
148 if(e == null) {
149 throw new IllegalStateException("DhDsaExchange not initialized!");
150 }
151
152 if(BigInteger.ZERO.compareTo(f) >= 0 || p.compareTo(f) <= 0) {
153 throw new IllegalArgumentException("Invalid f specified!");
154 }
155
156 this.f = f;
157 this.k = f.modPow(x, p);
158 }
159
160 /**
161 * @param e
162 */
163 public void setE(BigInteger e) {
164 if(f == null) {
165 throw new IllegalStateException("DhDsaExchange not initialized!");
166 }
167
168 if(BigInteger.ZERO.compareTo(e) >= 0 || p.compareTo(e) <= 0) {
169 throw new IllegalArgumentException("Invalid e specified!");
170 }
171
172 this.e = e;
173 this.k = e.modPow(y, p);
174 }
175
176 public byte[] calculateH(byte[] clientversion, byte[] serverversion, byte[] clientKexPayload,
177 byte[] serverKexPayload, byte[] hostKey) throws IOException {
178 HashForSSH2Types hash = new HashForSSH2Types("SHA1");
179
180 if(log.isInfoEnabled()) {
181 log.info("Client: '" + StringEncoder.GetString(clientversion) + "'");
182 log.info("Server: '" + StringEncoder.GetString(serverversion) + "'");
183 }
184
185 hash.updateByteString(clientversion);
186 hash.updateByteString(serverversion);
187 hash.updateByteString(clientKexPayload);
188 hash.updateByteString(serverKexPayload);
189 hash.updateByteString(hostKey);
190 hash.updateBigInt(e);
191 hash.updateBigInt(f);
192 hash.updateBigInt(k);
193
194 return hash.getDigest();
195 }
196 }