aboutsummaryrefslogtreecommitdiff
path: root/nx-X11/programs/Xserver/os/xdmauth.c
blob: 2e061d5e1d63fbfe9953ec365cd511ba12fe7bf5 (plain)
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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
/*

Copyright 1988, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.

*/

/*
 * XDM-AUTHENTICATION-1 (XDMCP authentication) and
 * XDM-AUTHORIZATION-1 (client authorization) protocols
 *
 * Author:  Keith Packard, MIT X Consortium
 */

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <stdio.h>
#include <nx-X11/X.h>
#define XSERV_t
#define TRANS_SERVER
#define TRANS_REOPEN
#include <nx-X11/Xtrans/Xtrans.h>
#include "os.h"
#include "osdep.h"
#include "dixstruct.h"

#ifdef HASXDMAUTH

static Bool authFromXDMCP;

#ifdef XDMCP
#include <nx-X11/Xmd.h>
#undef REQUEST
#include <X11/Xdmcp.h>

/* XDM-AUTHENTICATION-1 */

static XdmAuthKeyRec	privateKey;
static char XdmAuthenticationName[] = "XDM-AUTHENTICATION-1";
#define XdmAuthenticationNameLen (sizeof XdmAuthenticationName - 1)
static XdmAuthKeyRec	rho;

static Bool 
XdmAuthenticationValidator (ARRAY8Ptr privateData, ARRAY8Ptr incomingData, 
    xdmOpCode packet_type)
{
    XdmAuthKeyPtr	incoming;

    XdmcpUnwrap (incomingData->data, &privateKey,
			      incomingData->data,incomingData->length);
    if (packet_type == ACCEPT) {
    	if (incomingData->length != 8)
	    return FALSE;
    	incoming = (XdmAuthKeyPtr) incomingData->data;
    	XdmcpDecrementKey (incoming);
    	return XdmcpCompareKeys (incoming, &rho);
    }
    return FALSE;
}

static Bool
XdmAuthenticationGenerator (ARRAY8Ptr privateData, ARRAY8Ptr outgoingData, 
    xdmOpCode packet_type)
{
    outgoingData->length = 0;
    outgoingData->data = 0;
    if (packet_type == REQUEST) {
	if (XdmcpAllocARRAY8 (outgoingData, 8))
	    XdmcpWrap (&rho, &privateKey, outgoingData->data, 8);
    }
    return TRUE;
}

static Bool
XdmAuthenticationAddAuth (int name_len, char *name, 
    int data_len, char *data)
{
    Bool    ret;
    XdmcpUnwrap (data, (unsigned char *)&privateKey, data, data_len);
    authFromXDMCP = TRUE;
    ret = AddAuthorization (name_len, name, data_len, data);
    authFromXDMCP = FALSE;
    return ret;
}


#define atox(c)	('0' <= c && c <= '9' ? c - '0' : \
		 'a' <= c && c <= 'f' ? c - 'a' + 10 : \
		 'A' <= c && c <= 'F' ? c - 'A' + 10 : -1)

static int
HexToBinary (char *in, char *out, int len)
{
    int	    top, bottom;

    while (len > 0)
    {
	top = atox(in[0]);
	if (top == -1)
	    return 0;
	bottom = atox(in[1]);
	if (bottom == -1)
	    return 0;
	*out++ = (top << 4) | bottom;
	in += 2;
	len -= 2;
    }
    if (len)
	return 0;
    *out++ = '\0';
    return 1;
}

void
XdmAuthenticationInit (char *cookie, int cookie_len)
{
    bzero (privateKey.data, 8);
    if (!strncmp (cookie, "0x", 2) || !strncmp (cookie, "0X", 2))
    {
	if (cookie_len > 2 + 2 * 8)
	    cookie_len = 2 + 2 * 8;
	HexToBinary (cookie + 2, (char *)privateKey.data, cookie_len - 2);
    }
    else
    {
    	if (cookie_len > 7)
	    cookie_len = 7;
    	memmove (privateKey.data + 1, cookie, cookie_len);
    }
    XdmcpGenerateKey (&rho);
    XdmcpRegisterAuthentication (XdmAuthenticationName, XdmAuthenticationNameLen,
				 (unsigned char *)&rho,
				 sizeof (rho),
				 XdmAuthenticationValidator,
				 XdmAuthenticationGenerator,
				 XdmAuthenticationAddAuth);
}

#endif /* XDMCP */

/* XDM-AUTHORIZATION-1 */
typedef struct _XdmAuthorization {
    struct _XdmAuthorization	*next;
    XdmAuthKeyRec		rho;
    XdmAuthKeyRec		key;
    XID				id;
} XdmAuthorizationRec, *XdmAuthorizationPtr;

static XdmAuthorizationPtr xdmAuth;

typedef struct _XdmClientAuth {
    struct _XdmClientAuth   *next;
    XdmAuthKeyRec	    rho;
    char		    client[6];
    long		    time;
} XdmClientAuthRec, *XdmClientAuthPtr;

static XdmClientAuthPtr    xdmClients;
static long	    clockOffset;
static Bool	    gotClock;

#define TwentyMinutes	(20 * 60)
#define TwentyFiveMinutes (25 * 60)

static Bool
XdmClientAuthCompare (XdmClientAuthPtr a, XdmClientAuthPtr b)
{
    int	i;

    if (!XdmcpCompareKeys (&a->rho, &b->rho))
	return FALSE;
    for (i = 0; i < 6; i++)
	if (a->client[i] != b->client[i])
	    return FALSE;
    return a->time == b->time;
}

static void
XdmClientAuthDecode (unsigned char *plain, XdmClientAuthPtr auth)
{
    int	    i, j;

    j = 0;
    for (i = 0; i < 8; i++)
    {
	auth->rho.data[i] = plain[j];
	++j;
    }
    for (i = 0; i < 6; i++)
    {
	auth->client[i] = plain[j];
	++j;
    }
    auth->time = 0;
    for (i = 0; i < 4; i++)
    {
	auth->time |= plain[j] << ((3 - i) << 3);
	j++;
    }
}

static void
XdmClientAuthTimeout (long now)
{
    XdmClientAuthPtr	client, next, prev;

    prev = 0;
    for (client = xdmClients; client; client=next)
    {
	next = client->next;
	if (abs (now - client->time) > TwentyFiveMinutes)
	{
	    if (prev)
		prev->next = next;
	    else
		xdmClients = next;
	    free (client);
	}
	else
	    prev = client;
    }
}

static XdmClientAuthPtr
XdmAuthorizationValidate (unsigned char *plain, int length, 
    XdmAuthKeyPtr rho, ClientPtr xclient, char **reason)
{
    XdmClientAuthPtr	client, existing;
    long		now;
    int			i;

    if (length != (192 / 8)) {
	if (reason)
	    *reason = "Bad XDM authorization key length";
	return NULL;
    }
    client = (XdmClientAuthPtr) malloc (sizeof (XdmClientAuthRec));
    if (!client)
	return NULL;
    XdmClientAuthDecode (plain, client);
    if (!XdmcpCompareKeys (&client->rho, rho))
    {
	free (client);
	if (reason)
	    *reason = "Invalid XDM-AUTHORIZATION-1 key (failed key comparison)";
	return NULL;
    }
    for (i = 18; i < 24; i++)
	if (plain[i] != 0) {
	    free (client);
	    if (reason)
		*reason = "Invalid XDM-AUTHORIZATION-1 key (failed NULL check)";
	    return NULL;
	}
    if (xclient) {
	int family, addr_len;
	Xtransaddr *addr;

	if (_XSERVTransGetPeerAddr(((OsCommPtr)xclient->osPrivate)->trans_conn,
				   &family, &addr_len, &addr) == 0
	    && _XSERVTransConvertAddress(&family, &addr_len, &addr) == 0) {
#if defined(TCPCONN) || defined(STREAMSCONN)
	    if (family == FamilyInternet &&
		memcmp((char *)addr, client->client, 4) != 0) {
		free (client);
		free (addr);
		if (reason)
		    *reason = "Invalid XDM-AUTHORIZATION-1 key (failed address comparison)";
		return NULL;

	    }
#endif
	    free (addr);
	}
    }
    now = time(0);
    if (!gotClock)
    {
	clockOffset = client->time - now;
	gotClock = TRUE;
    }
    now += clockOffset;
    XdmClientAuthTimeout (now);
    if (abs (client->time - now) > TwentyMinutes)
    {
	free (client);
	if (reason)
	    *reason = "Excessive XDM-AUTHORIZATION-1 time offset";
	return NULL;
    }
    for (existing = xdmClients; existing; existing=existing->next)
    {
	if (XdmClientAuthCompare (existing, client))
	{
	    free (client);
	    if (reason)
		*reason = "XDM authorization key matches an existing client!";
	    return NULL;
	}
    }
    return client;
}

int
XdmAddCookie (unsigned short data_length, char *data, XID id)
{
    XdmAuthorizationPtr	new;
    unsigned char	*rho_bits, *key_bits;

    switch (data_length)
    {
    case 16:		    /* auth from files is 16 bytes long */
#ifdef XDMCP
	if (authFromXDMCP)
	{
	    /* R5 xdm sent bogus authorization data in the accept packet,
	     * but we can recover */
	    rho_bits = rho.data;
	    key_bits = (unsigned char *) data;
	    key_bits[0] = '\0';
	}
	else
#endif
	{
	    rho_bits = (unsigned char *) data;
	    key_bits = (unsigned char *) (data + 8);
	}
	break;
#ifdef XDMCP
    case 8:		    /* auth from XDMCP is 8 bytes long */
	rho_bits = rho.data;
	key_bits = (unsigned char *) data;
	break;
#endif
    default:
	return 0;
    }
    /* the first octet of the key must be zero */
    if (key_bits[0] != '\0')
	return 0;
    new = (XdmAuthorizationPtr) malloc (sizeof (XdmAuthorizationRec));
    if (!new)
	return 0;
    new->next = xdmAuth;
    xdmAuth = new;
    memmove (new->key.data, key_bits, (int) 8);
    memmove (new->rho.data, rho_bits, (int) 8);
    new->id = id;
    return 1;
}

XID
XdmCheckCookie (unsigned short cookie_length, char *cookie, 
    ClientPtr xclient, char **reason)
{
    XdmAuthorizationPtr	auth;
    XdmClientAuthPtr	client;
    unsigned char	*plain;

    /* Auth packets must be a multiple of 8 bytes long */
    if (cookie_length & 7)
	return (XID) -1;
    plain = (unsigned char *) malloc (cookie_length);
    if (!plain)
	return (XID) -1;
    for (auth = xdmAuth; auth; auth=auth->next) {
	XdmcpUnwrap (cookie, (unsigned char *)&auth->key, plain, cookie_length);
	if ((client = XdmAuthorizationValidate (plain, cookie_length, &auth->rho, xclient, reason)) != NULL)
	{
	    client->next = xdmClients;
	    xdmClients = client;
	    free (plain);
	    return auth->id;
	}
    }
    free (plain);
    return (XID) -1;
}

int
XdmResetCookie (void)
{
    XdmAuthorizationPtr	auth, next_auth;
    XdmClientAuthPtr	client, next_client;

    for (auth = xdmAuth; auth; auth=next_auth)
    {
	next_auth = auth->next;
	free (auth);
    }
    xdmAuth = 0;
    for (client = xdmClients; client; client=next_client)
    {
	next_client = client->next;
	free (client);
    }
    xdmClients = (XdmClientAuthPtr) 0;
    return 1;
}

XID
XdmToID (unsigned short cookie_length, char *cookie)
{
    XdmAuthorizationPtr	auth;
    XdmClientAuthPtr	client;
    unsigned char	*plain;

    plain = (unsigned char *) malloc (cookie_length);
    if (!plain)
	return (XID) -1;
    for (auth = xdmAuth; auth; auth=auth->next) {
	XdmcpUnwrap (cookie, (unsigned char *)&auth->key, plain, cookie_length);
	if ((client = XdmAuthorizationValidate (plain, cookie_length, &auth->rho, NULL, NULL)) != NULL)
	{
	    free (client);
	    free (cookie);
	    return auth->id;
	}
    }
    free (cookie);
    return (XID) -1;
}

int
XdmFromID (XID id, unsigned short *data_lenp, char **datap)
{
    XdmAuthorizationPtr	auth;

    for (auth = xdmAuth; auth; auth=auth->next) {
	if (id == auth->id) {
	    *data_lenp = 16;
	    *datap = (char *) &auth->rho;
	    return 1;
	}
    }
    return 0;
}

int
XdmRemoveCookie (unsigned short data_length, char *data)
{
    XdmAuthorizationPtr	auth, prev;
    XdmAuthKeyPtr	key_bits, rho_bits;

    prev = 0;
    switch (data_length)
    {
    case 16:
	rho_bits = (XdmAuthKeyPtr) data;
	key_bits = (XdmAuthKeyPtr) (data + 8);
	break;
#ifdef XDMCP
    case 8:
	rho_bits = &rho;
	key_bits = (XdmAuthKeyPtr) data;
	break;
#endif
    default:
	return 0;
    }
    for (auth = xdmAuth; auth; auth=auth->next) {
	if (XdmcpCompareKeys (rho_bits, &auth->rho) &&
	    XdmcpCompareKeys (key_bits, &auth->key))
 	{
	    if (prev)
		prev->next = auth->next;
	    else
		xdmAuth = auth->next;
	    free (auth);
	    return 1;
	}
    }
    return 0;
}

#endif