mitauth.c revision 030cabe0 
1/*
2
3Copyright 1988, 1998  The Open Group
4
5Permission to use, copy, modify, distribute, and sell this software and its
6documentation for any purpose is hereby granted without fee, provided that
7the above copyright notice appear in all copies and that both that
8copyright notice and this permission notice appear in supporting
9documentation.
10
11The above copyright notice and this permission notice shall be included
12in all copies or substantial portions of the Software.
13
14THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
15OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
17IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
18OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20OTHER DEALINGS IN THE SOFTWARE.
21
22Except as contained in this notice, the name of The Open Group shall
23not be used in advertising or otherwise to promote the sale, use or
24other dealings in this Software without prior written authorization
25from The Open Group.
26
27*/
28
29/*
30 * MIT-MAGIC-COOKIE-1 authorization scheme
31 * Author:  Keith Packard, MIT X Consortium
32 */
33
34#ifdef HAVE_DIX_CONFIG_H
35#include <dix-config.h>
36#endif
37
38#include <X11/X.h>
39#include "os.h"
40#include "osdep.h"
41#include "dixstruct.h"
42
43static struct auth {
44    struct auth	*next;
45    unsigned short	len;
46    char	*data;
47    XID		id;
48} *mit_auth;
49
50int
51MitAddCookie (
52    unsigned short	data_length,
53    const char		*data,
54    XID			id)
55{
56    struct auth	*new;
57
58    new = malloc(sizeof (struct auth));
59    if (!new)
60	return 0;
61    new->data = malloc((unsigned) data_length);
62    if (!new->data) {
63	free(new);
64	return 0;
65    }
66    new->next = mit_auth;
67    mit_auth = new;
68    memmove(new->data, data, (int) data_length);
69    new->len = data_length;
70    new->id = id;
71    return 1;
72}
73
74XID
75MitCheckCookie (
76    unsigned short	data_length,
77    const char		*data,
78    ClientPtr		client,
79    char		**reason)
80{
81    struct auth	*auth;
82
83    for (auth = mit_auth; auth; auth=auth->next) {
84        if (data_length == auth->len &&
85	   timingsafe_memcmp(data, auth->data, (int) data_length) == 0)
86	    return auth->id;
87    }
88    *reason = "Invalid MIT-MAGIC-COOKIE-1 key";
89    return (XID) -1;
90}
91
92int
93MitResetCookie (void)
94{
95    struct auth	*auth, *next;
96
97    for (auth = mit_auth; auth; auth=next) {
98	next = auth->next;
99	free(auth->data);
100	free(auth);
101    }
102    mit_auth = 0;
103    return 0;
104}
105
106int
107MitFromID (
108	XID		id,
109	unsigned short	*data_lenp,
110	char		**datap)
111{
112    struct auth	*auth;
113
114    for (auth = mit_auth; auth; auth=auth->next) {
115	if (id == auth->id) {
116	    *data_lenp = auth->len;
117	    *datap = auth->data;
118	    return 1;
119	}
120    }
121    return 0;
122}
123
124int
125MitRemoveCookie (
126	unsigned short	data_length,
127	const char	*data)
128{
129    struct auth	*auth, *prev;
130
131    prev = 0;
132    for (auth = mit_auth; auth; prev = auth, auth=auth->next) {
133	if (data_length == auth->len &&
134	    memcmp (data, auth->data, data_length) == 0)
135 	{
136	    if (prev)
137		prev->next = auth->next;
138	    else
139		mit_auth = auth->next;
140	    free(auth->data);
141	    free(auth);
142	    return 1;
143	}
144    }
145    return 0;
146}
147
148#ifdef XCSECURITY
149
150static char cookie[16]; /* 128 bits */
151
152XID
153MitGenerateCookie (
154    unsigned	data_length,
155    const char	*data,
156    XID		id,
157    unsigned	*data_length_return,
158    char	**data_return)
159{
160    int i = 0;
161    int status;
162
163    while (data_length--)
164    {
165	cookie[i++] += *data++;
166	if (i >= sizeof (cookie)) i = 0;
167    }
168    GenerateRandomData(sizeof (cookie), cookie);
169    status = MitAddCookie(sizeof (cookie), cookie, id);
170    if (!status)
171    {
172	id = -1;
173    }
174    else
175    {
176	*data_return = cookie;
177	*data_length_return = sizeof (cookie);
178    }
179    return id;
180}
181
182#endif /* XCSECURITY */
183