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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
* Copyright (C) 1999 AT&T Laboratories Cambridge. All Rights Reserved.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
/*
* vncauth.c - Functions for VNC password management and authentication.
*/
#ifdef __STRICT_ANSI__
#define _BSD_SOURCE
#define _POSIX_SOURCE
#endif
#ifdef LIBVNCSERVER_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "rfb/rfbproto.h"
#include "d3des.h"
#include <string.h>
#include <math.h>
#ifdef LIBVNCSERVER_HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <time.h>
#ifdef WIN32
#define srandom srand
#define random rand
#else
#include <sys/time.h>
#endif
/* libvncclient does not need this */
#ifndef rfbEncryptBytes
/*
* We use a fixed key to store passwords, since we assume that our local
* file system is secure but nonetheless don't want to store passwords
* as plaintext.
*/
static unsigned char fixedkey[8] = {23,82,107,6,35,78,88,7};
/*
* Encrypt a password and store it in a file. Returns 0 if successful,
* 1 if the file could not be written.
*/
int
rfbEncryptAndStorePasswd(char *passwd, char *fname)
{
FILE *fp;
unsigned int i;
unsigned char encryptedPasswd[8];
if ((fp = fopen(fname,"w")) == NULL) return 1;
/* windows security sux */
#ifndef WIN32
fchmod(fileno(fp), S_IRUSR|S_IWUSR);
#endif
/* pad password with nulls */
for (i = 0; i < 8; i++) {
if (i < strlen(passwd)) {
encryptedPasswd[i] = passwd[i];
} else {
encryptedPasswd[i] = 0;
}
}
/* Do encryption in-place - this way we overwrite our copy of the plaintext
password */
rfbDesKey(fixedkey, EN0);
rfbDes(encryptedPasswd, encryptedPasswd);
for (i = 0; i < 8; i++) {
putc(encryptedPasswd[i], fp);
}
fclose(fp);
return 0;
}
/*
* Decrypt a password from a file. Returns a pointer to a newly allocated
* string containing the password or a null pointer if the password could
* not be retrieved for some reason.
*/
char *
rfbDecryptPasswdFromFile(char *fname)
{
FILE *fp;
int i, ch;
unsigned char *passwd = (unsigned char *)malloc(9);
if ((fp = fopen(fname,"r")) == NULL) return NULL;
for (i = 0; i < 8; i++) {
ch = getc(fp);
if (ch == EOF) {
fclose(fp);
return NULL;
}
passwd[i] = ch;
}
fclose(fp);
rfbDesKey(fixedkey, DE1);
rfbDes(passwd, passwd);
passwd[8] = 0;
return (char *)passwd;
}
/*
* Generate CHALLENGESIZE random bytes for use in challenge-response
* authentication.
*/
void
rfbRandomBytes(unsigned char *bytes)
{
int i;
static rfbBool s_srandom_called = FALSE;
if (!s_srandom_called) {
srandom((unsigned int)time(NULL) ^ (unsigned int)getpid());
s_srandom_called = TRUE;
}
for (i = 0; i < CHALLENGESIZE; i++) {
bytes[i] = (unsigned char)(random() & 255);
}
}
#endif
/*
* Encrypt CHALLENGESIZE bytes in memory using a password.
*/
void
rfbEncryptBytes(unsigned char *bytes, char *passwd)
{
unsigned char key[8];
unsigned int i;
/* key is simply password padded with nulls */
for (i = 0; i < 8; i++) {
if (i < strlen(passwd)) {
key[i] = passwd[i];
} else {
key[i] = 0;
}
}
rfbDesKey(key, EN0);
for (i = 0; i < CHALLENGESIZE; i += 8) {
rfbDes(bytes+i, bytes+i);
}
}
|
