Source code: mindbright/ssh/SSHRSAKeyFile.java
1 /******************************************************************************
2 *
3 * Copyright (c) 1998,99 by Mindbright Technology AB, Stockholm, Sweden.
4 * www.mindbright.se, info@mindbright.se
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 *****************************************************************************
17 * $Author: nallen $
18 * $Date: 2001/11/12 16:31:21 $
19 * $Name: $
20 *****************************************************************************/
21 package mindbright.ssh;
22
23 import java.io.*;
24 import java.math.BigInteger;
25
26 import mindbright.security.*;
27
28 public class SSHRSAKeyFile {
29
30 //
31 //
32 int cipherType;
33 RSAPublicKey pubKey;
34 String fileComment;
35
36 byte[] encrypted;
37
38 final static String privFileId = "SSH PRIVATE KEY FILE FORMAT 1.1\n";
39
40 static public void createKeyFile(KeyPair kp, String passwd, String name, String comment)
41 throws IOException {
42 RSAPrivateKey privKey = (RSAPrivateKey)kp.getPrivate();
43
44 ByteArrayOutputStream baos = new ByteArrayOutputStream(8192);
45 SSHDataOutputStream dataOut = new SSHDataOutputStream(baos);
46
47 byte[] c = new byte[2];
48 SSH.secureRandom().nextBytes(c);
49 dataOut.writeByte((int)c[0]);
50 dataOut.writeByte((int)c[1]);
51 dataOut.writeByte((int)c[0]);
52 dataOut.writeByte((int)c[1]);
53 dataOut.writeBigInteger(privKey.getD());
54 dataOut.writeBigInteger(privKey.getU());
55 dataOut.writeBigInteger(privKey.getP());
56 dataOut.writeBigInteger(privKey.getQ());
57
58 byte[] encrypted = baos.toByteArray();
59 c = new byte[(8 - (encrypted.length % 8)) + encrypted.length];
60 System.arraycopy(encrypted, 0, c, 0, encrypted.length);
61 encrypted = c;
62
63 int cipherType = SSH.CIPHER_DEFAULT;
64
65 Cipher cipher = Cipher.getInstance(SSH.cipherClasses[cipherType][0]);
66 cipher.setKey(passwd);
67 encrypted = cipher.encrypt(encrypted);
68
69 FileOutputStream fileOut = new FileOutputStream(name);
70 dataOut = new SSHDataOutputStream(fileOut);
71
72 dataOut.writeBytes(privFileId);
73 dataOut.writeByte(0);
74
75 dataOut.writeByte(cipherType);
76 dataOut.writeInt(0);
77 dataOut.writeInt(0);
78 dataOut.writeBigInteger(((RSAPublicKey)kp.getPublic()).getN());
79 dataOut.writeBigInteger(((RSAPublicKey)kp.getPublic()).getE());
80 dataOut.writeString(comment);
81
82 dataOut.write(encrypted, 0, encrypted.length);
83 dataOut.close();
84 }
85
86 public SSHRSAKeyFile(String name) throws IOException {
87 FileInputStream fileIn = new FileInputStream(name);
88 SSHDataInputStream dataIn = new SSHDataInputStream(fileIn);
89
90 byte[] id = new byte[privFileId.length()];
91 dataIn.readFully(id);
92 String idStr = new String(id);
93 dataIn.readByte(); // Skip end-of-string (?!)
94
95 if(!idStr.equals(privFileId))
96 throw new IOException("RSA key file corrupt");
97
98 cipherType = dataIn.readByte();
99 if(SSH.cipherClasses[cipherType][0] == null)
100 throw new IOException("Ciphertype " + cipherType + " in key-file not supported");
101
102 dataIn.readInt(); // Skip a reserved int
103
104 dataIn.readInt(); // Skip bits... (!?)
105
106 BigInteger n = dataIn.readBigInteger();
107 BigInteger e = dataIn.readBigInteger();
108 pubKey = new RSAPublicKey(e, n);
109
110 fileComment = dataIn.readString();
111
112 byte[] rest = new byte[8192];
113 int len = dataIn.read(rest);
114 dataIn.close();
115
116 encrypted = new byte[len];
117 System.arraycopy(rest, 0, encrypted, 0, len);
118 }
119
120 public String getComment() {
121 return fileComment;
122 }
123
124 public RSAPublicKey getPublic() {
125 return pubKey;
126 }
127
128 public RSAPrivateKey getPrivate(String passwd) {
129 RSAPrivateKey privKey = null;
130
131 Cipher cipher = Cipher.getInstance(SSH.cipherClasses[cipherType][0]);
132 cipher.setKey(passwd);
133 byte[] decrypted = cipher.decrypt(encrypted);
134 SSHDataInputStream dataIn = new SSHDataInputStream(new ByteArrayInputStream(decrypted));
135
136 try {
137 byte c1 = dataIn.readByte();
138 byte c2 = dataIn.readByte();
139 byte c11 = dataIn.readByte();
140 byte c22 = dataIn.readByte();
141
142 if(c1 != c11 || c2 != c22)
143 return null;
144
145 BigInteger d = dataIn.readBigInteger();
146 BigInteger u = dataIn.readBigInteger();
147 BigInteger p = dataIn.readBigInteger();
148 BigInteger q = dataIn.readBigInteger();
149 dataIn.close();
150
151 privKey = new RSAPrivateKey(pubKey.getE(), pubKey.getN(),
152 d, u, p, q);
153 } catch (IOException e) {
154 privKey = null;
155 }
156
157 return privKey;
158 }
159
160 /* !!! DEBUG
161 public static void main(String[] argv) {
162 SSHRSAKeyFile file = null;
163
164 try {
165 file = new SSHRSAKeyFile("/home/mats/.ssh/identity");
166 file.getPrivate("********");
167 } catch (Exception e) {
168 System.out.println("Error: " + e.toString());
169 }
170 System.out.println("Comment: " + file.fileComment);
171 }
172 */
173
174 }
175
176