Key.c revision 515ec619 
1/*
2Copyright 1989, 1998  The Open Group
3
4Permission to use, copy, modify, distribute, and sell this software and its
5documentation for any purpose is hereby granted without fee, provided that
6the above copyright notice appear in all copies and that both that
7copyright notice and this permission notice appear in supporting
8documentation.
9
10The above copyright notice and this permission notice shall be included in
11all copies or substantial portions of the Software.
12
13THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
16OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
17AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
18CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
19
20Except as contained in this notice, the name of The Open Group shall not be
21used in advertising or otherwise to promote the sale, use or other dealings
22in this Software without prior written authorization from The Open Group.
23 *
24 * Author:  Keith Packard, MIT X Consortium
25 */
26
27#ifdef HAVE_CONFIG_H
28#include <config.h>
29#endif
30#include <X11/Xos.h>
31#include <X11/X.h>
32#include <X11/Xmd.h>
33#include <X11/Xdmcp.h>
34
35#ifndef HAVE_ARC4RANDOM_BUF
36static void
37getbits (long data, unsigned char *dst)
38{
39    dst[0] = (data      ) & 0xff;
40    dst[1] = (data >>  8) & 0xff;
41    dst[2] = (data >> 16) & 0xff;
42    dst[3] = (data >> 24) & 0xff;
43}
44#endif
45
46#define Time_t time_t
47
48#include <stdlib.h>
49
50#if defined(HAVE_LRAND48) && defined(HAVE_SRAND48)
51#define srandom srand48
52#define random lrand48
53#endif
54#ifdef WIN32
55#include <process.h>
56#define srandom srand
57#define random rand
58#define getpid(x) _getpid(x)
59#endif
60
61#ifndef HAVE_ARC4RANDOM_BUF
62
63/* Solaris 11.3.0 - 11.4.15 only define getentropy() in <sys/random.h> */
64#if HAVE_GETENTROPY && HAVE_SYS_RANDOM_H
65# include <sys/random.h>
66#endif
67
68static void
69insecure_getrandom_buf (unsigned char *auth, int len)
70{
71    long    lowbits, highbits;
72
73    srandom ((int)getpid() ^ time((Time_t *)0));
74    lowbits = random ();
75    highbits = random ();
76    getbits (lowbits, auth);
77    getbits (highbits, auth + 4);
78}
79
80static void
81arc4random_buf (void *auth, int len)
82{
83#if HAVE_GETENTROPY
84    int	    ret;
85
86    /* weak emulation of arc4random through the getentropy libc call */
87    ret = getentropy (auth, len);
88    if (ret == 0)
89	return;
90#endif /* HAVE_GETENTROPY */
91
92    insecure_getrandom_buf (auth, len);
93}
94
95#endif /* !defined(HAVE_ARC4RANDOM_BUF) */
96
97void
98XdmcpGenerateKey (XdmAuthKeyPtr key)
99{
100    arc4random_buf(key->data, 8);
101}
102
103int
104XdmcpCompareKeys (const XdmAuthKeyPtr a, const XdmAuthKeyPtr b)
105{
106    int	i;
107
108    for (i = 0; i < 8; i++)
109	if (a->data[i] != b->data[i])
110	    return FALSE;
111    return TRUE;
112}
113
114void
115XdmcpIncrementKey (XdmAuthKeyPtr key)
116{
117    int	i;
118
119    i = 7;
120    while (++key->data[i] == 0)
121	if (--i < 0)
122	    break;
123}
124
125void
126XdmcpDecrementKey (XdmAuthKeyPtr key)
127{
128    int	i;
129
130    i = 7;
131    while (key->data[i]-- == 0)
132	if (--i < 0)
133	    break;
134}
135