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1
19
20 package com.sslexplorer.security.pki.dsa;
21
22 import java.io.IOException  ;
23 import java.math.BigInteger ;
24 import java.security.KeyFactory ;
25 import java.security.PrivateKey ;
26 import java.security.Signature ;
27 import java.security.interfaces.DSAPrivateKey ;
28 import java.security.interfaces.DSAPublicKey ;
29 import java.security.spec.DSAPrivateKeySpec ;
30 import java.security.spec.DSAPublicKeySpec ;
31
32 import org.apache.commons.logging.Log;
33 import org.apache.commons.logging.LogFactory;
34
35 import com.maverick.util.ByteArrayReader;
36 import com.maverick.util.ByteArrayWriter;
37 import com.sslexplorer.security.pki.InvalidKeyException;
38 import com.sslexplorer.security.pki.InvalidSignatureException;
39 import com.sslexplorer.security.pki.SimpleASNReader;
40 import com.sslexplorer.security.pki.SshPrivateKey;
41 import com.sslexplorer.security.pki.SshPublicKey;
42
43
44 class SshDssPrivateKey extends SshPrivateKey {
45 private static Log log = LogFactory.getLog(SshDssPrivateKey.class);
46 DSAPrivateKey prvkey;
47
48
53 public SshDssPrivateKey(DSAPrivateKey prvkey) {
54 this.prvkey = prvkey;
55 }
56
57 public PrivateKey getPrivateKey() {
58 return prvkey;
59 }
60
61
68 public SshDssPrivateKey(byte[] key) throws InvalidKeyException {
69 try {
70 DSAPrivateKeySpec dsaKey;
71
72 ByteArrayReader bar = new ByteArrayReader(key);
74 String header = bar.readString();
75
76 if (!header.equals(getAlgorithmName())) {
77 throw new InvalidKeyException();
78 }
79
80 BigInteger p = bar.readBigInteger();
81 BigInteger q = bar.readBigInteger();
82 BigInteger g = bar.readBigInteger();
83 BigInteger x = bar.readBigInteger();
84 dsaKey = new DSAPrivateKeySpec (x, p, q, g);
85
86 KeyFactory kf = KeyFactory.getInstance("DSA");
87 prvkey = (DSAPrivateKey ) kf.generatePrivate(dsaKey);
88 } catch (Exception e) {
89 throw new InvalidKeyException();
90 }
91 }
92
93
100 public boolean equals(Object obj) {
101 if (obj instanceof SshDssPrivateKey) {
102 return prvkey.equals(((SshDssPrivateKey) obj).prvkey);
103 }
104
105 return false;
106 }
107
108
113 public int hashCode() {
114 return prvkey.hashCode();
115 }
116
117
122 public String getAlgorithmName() {
123 return "ssh-dss";
124 }
125
126
131 public int getBitLength() {
132 return prvkey.getX().bitLength();
133 }
134
135
140 public byte[] getEncoded() {
141 try {
142 ByteArrayWriter baw = new ByteArrayWriter();
143 baw.writeString("ssh-dss");
144 baw.writeBigInteger(prvkey.getParams().getP());
145 baw.writeBigInteger(prvkey.getParams().getQ());
146 baw.writeBigInteger(prvkey.getParams().getG());
147 baw.writeBigInteger(prvkey.getX());
148
149 return baw.toByteArray();
150 } catch (IOException ioe) {
151 return null;
152 }
153 }
154
155
160 public SshPublicKey getPublicKey() {
161 try {
162 DSAPublicKeySpec spec = new DSAPublicKeySpec (getY(),
163 prvkey.getParams().getP(), prvkey.getParams().getQ(),
164 prvkey.getParams().getG());
165 KeyFactory kf = KeyFactory.getInstance("DSA");
166
167 return new SshDssPublicKey((DSAPublicKey ) kf.generatePublic(spec));
168 } catch (Exception e) {
169 return null;
170 }
171 }
172
173
182 public byte[] generateSignature(byte[] data)
183 throws InvalidSignatureException {
184 try {
185 Signature sig = Signature.getInstance("SHA1withDSA");
186 sig.initSign(prvkey);
187
188 sig.update(data);
189
190 byte[] signature = sig.sign();
191 byte[] decoded = new byte[40];
192 SimpleASNReader asn = new SimpleASNReader(signature);
193 asn.getByte();
194 asn.getLength();
195 asn.getByte();
196
197 byte[] r = asn.getData();
198 asn.getByte();
199
200 byte[] s = asn.getData();
201
202 if (r.length >= 20) {
203 System.arraycopy(r, r.length - 20, decoded, 0, 20);
204 } else {
205 System.arraycopy(r, 0, decoded, 20 - r.length, r.length);
206 }
207
208 if (s.length >= 20) {
209 System.arraycopy(s, s.length - 20, decoded, 20, 20);
210 } else {
211 System.arraycopy(s, 0, decoded, 20 + (20 - s.length), s.length);
212 }
213
214 if (log.isDebugEnabled()) {
215 log.debug("s length is " + String.valueOf(s.length));
216 log.debug("r length is " + String.valueOf(r.length));
217
218 String str = "";
219
220 for (int i = 0; i < signature.length; i++) {
221 str += (Integer.toHexString(signature[i] & 0xFF) + " ");
222 }
223
224 log.debug("Java signature is " + str);
225 str = "";
226
227 for (int i = 0; i < decoded.length; i++) {
228 str += (Integer.toHexString(decoded[i] & 0xFF) + " ");
229 }
230
231 log.debug("SSH signature is " + str);
232 }
233
234 ByteArrayWriter baw = new ByteArrayWriter();
235 baw.writeString(getAlgorithmName());
236 baw.writeBinaryString(decoded);
237
238 return baw.toByteArray();
239 } catch (Exception e) {
240 throw new InvalidSignatureException(e);
241 }
242 }
243
244 private BigInteger getY() {
245 return prvkey.getParams().getG().modPow(prvkey.getX(),
246 prvkey.getParams().getP());
247 }
248 }
249 |
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