1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
/*******************************************************************************
* Copyright (c) 2000, 2003 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Common Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.team.internal.ccvs.ssh;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.math.BigInteger;
import java.util.Vector;
import org.eclipse.core.boot.BootLoader;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.team.internal.ccvs.ssh.Policy;
/**
* I represent a database of known hosts usually placed in ~/.ssh/known_hosts
* on Unix/Linux systems.
* Currently, only RSA keys are supported, as these are the only keys we
* have to deal with during SSH1 key exchange.
*/
public class KnownHosts {
private String filename;
public KnownHosts(String filename) {
this.filename = filename;
}
public KnownHosts() {
this.filename = KnownHosts.defaultFilename();
}
static String defaultFilename() {
if (!BootLoader.getOS().equals(BootLoader.OS_LINUX)) return internalFilename();
String HOME = System.getProperty("user.home"); //$NON-NLS-1$
if (HOME==null) return internalFilename();
return HOME+"/.ssh/known_hosts"; //$NON-NLS-1$
}
private static String internalFilename() {
return SSHPlugin.getPlugin().getStateLocation().append("known_hosts").toOSString(); //$NON-NLS-1$
}
/**
* Verify if the public key for the specified host is known.
* If the public key matches, return true.
* If the key does not match, return false.
* If the key is not listed in <code>known_hosts</code>, or
* <code>known_hosts</code> does not exist, assume we are connecting
* to the authentic server, add the key, and return true.
* @param e key exponent
* @param n key modulus
* @return boolean whether the key is correct
*/
public boolean verifyKey(String hostname, byte[] host_key_bits, BigInteger e, BigInteger n) {
FileReader f;
BigInteger nbits = new BigInteger(1, host_key_bits);
try {
f= new FileReader(filename);
} catch (FileNotFoundException ex) {
createHostFile();
addHost(hostname, nbits, e, n);
return true;
}
BufferedReader r = new BufferedReader(f);
try {
boolean found = false;
String line;
while ((line = r.readLine()) != null) {
if (line.trim().length()==0) continue;
if (line.startsWith("#")) continue; //$NON-NLS-1$
String[] tokens=subStrings(line);
if (tokens.length==4 && Character.isDigit(tokens[1].charAt(0)) && tokens[0].equalsIgnoreCase(hostname)) {
if (nbits.equals(new BigInteger(tokens[1])) && e.equals(new BigInteger(tokens[2])) && n.equals(new BigInteger(tokens[3]))) {
f.close();
return true;
} else {
f.close();
return false;
}
}
}
f.close();
addHost(hostname, nbits, e, n);
return true;
} catch (IOException ex) {
SSHPlugin.log(IStatus.ERROR, Policy.bind("KnownHosts.8"), ex); //$NON-NLS-1$
return false;
}
}
/*
* Append the host key information to known_hosts.
* Always assume the file exists.
*/
void addHost(String hostname, BigInteger key_bits, BigInteger e, BigInteger n) {
try {
FileWriter w = new FileWriter(defaultFilename(), true);
w.write(Character.LINE_SEPARATOR);
w.write(hostname + " " + key_bits.toString(10) + " " + e.toString(10) + " " + n.toString(10)); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
w.close();
String message = Policy.bind("Client.addedHostKey", new String[] {hostname, defaultFilename()}); //$NON-NLS-1$
SSHPlugin.log(IStatus.INFO, message, null);
} catch (IOException ex) {
SSHPlugin.log(IStatus.ERROR, Policy.bind("KnownHosts.9"), ex); //$NON-NLS-1$
}
}
/*
* Create the known_hosts file in the default location.
* Fail if the file can not be created (issue a warning in the log).
*/
void createHostFile() {
try {
File file = new File(defaultFilename());
// Ensure the parent directory exists
File parentDir = file.getParentFile();
parentDir.mkdirs();
// Create the file
file.createNewFile();
} catch (IOException ee) {
SSHPlugin.log(IStatus.ERROR, Policy.bind("KnownHosts.10"), ee); //$NON-NLS-1$
}
}
private static String[] subStrings(String s) {
Vector v = subStringsVector(s);
String[] substrings = new String[v.size()];
v.copyInto(substrings);
return substrings;
}
private static Vector subStringsVector(String s) {
Vector v = new Vector();
s = s.trim();
if (s.length()==0) return v;
int first1 = s.indexOf(' ');
int first2 = s.indexOf('\t');
int first;
if ((first1==-1)&&(first2==-1)) first=-1;
else if ((first1!=-1)&&(first2!=-1)) first = Math.min(first1, first2);
else if (first1!=-1) first=first1; else first=first2;
if (first==-1) {
v.add(s);
return v;
}
v.add(s.substring(0,first));
v.addAll(subStringsVector(s.substring(first+1)));
return v;
}
}
|
