summaryrefslogtreecommitdiff
path: root/Xext/security.c
blob: 162d07ae099d2cfea0915add8bb2941c71e31c9c (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
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
/*

Copyright 1996, 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.

*/

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

#include "scrnintstr.h"
#include "inputstr.h"
#include "windowstr.h"
#include "propertyst.h"
#include "colormapst.h"
#include "privates.h"
#include "registry.h"
#include "xacestr.h"
#include "securitysrv.h"
#include <X11/extensions/securproto.h>
#include "extinit.h"
#include "protocol-versions.h"

/* Extension stuff */
static int SecurityErrorBase;   /* first Security error number */
static int SecurityEventBase;   /* first Security event number */

RESTYPE SecurityAuthorizationResType;   /* resource type for authorizations */
static RESTYPE RTEventClient;

static CallbackListPtr SecurityValidateGroupCallback = NULL;

/* Private state record */
static DevPrivateKeyRec stateKeyRec;

#define stateKey (&stateKeyRec)

/* This is what we store as client security state */
typedef struct {
    unsigned int haveState  :1;
    unsigned int live       :1;
    unsigned int trustLevel :2;
    XID authId;
} SecurityStateRec;

/* The only extensions that untrusted clients have access to */
static const char *SecurityTrustedExtensions[] = {
    "XC-MISC",
    "BIG-REQUESTS",
    NULL
};

/*
 * Access modes that untrusted clients are allowed on trusted objects.
 */
static const Mask SecurityResourceMask =
    DixGetAttrAccess | DixReceiveAccess | DixListPropAccess |
    DixGetPropAccess | DixListAccess;
static const Mask SecurityWindowExtraMask = DixRemoveAccess;
static const Mask SecurityRootWindowExtraMask =
    DixReceiveAccess | DixSendAccess | DixAddAccess | DixRemoveAccess;
static const Mask SecurityDeviceMask =
    DixGetAttrAccess | DixReceiveAccess | DixGetFocusAccess |
    DixGrabAccess | DixSetAttrAccess | DixUseAccess;
static const Mask SecurityServerMask = DixGetAttrAccess | DixGrabAccess;
static const Mask SecurityClientMask = DixGetAttrAccess;

/* SecurityAudit
 *
 * Arguments:
 *	format is the formatting string to be used to interpret the
 *	  remaining arguments.
 *
 * Returns: nothing.
 *
 * Side Effects:
 *	Writes the message to the log file if security logging is on.
 */

static void
_X_ATTRIBUTE_PRINTF(1, 2)
SecurityAudit(const char *format, ...)
{
    va_list args;

    if (auditTrailLevel < SECURITY_AUDIT_LEVEL)
        return;
    va_start(args, format);
    VAuditF(format, args);
    va_end(args);
}                               /* SecurityAudit */

/*
 * Performs a Security permission check.
 */
static int
SecurityDoCheck(SecurityStateRec * subj, SecurityStateRec * obj,
                Mask requested, Mask allowed)
{
    if (!subj->haveState || !obj->haveState)
        return Success;
    if (subj->trustLevel == XSecurityClientTrusted)
        return Success;
    if (obj->trustLevel != XSecurityClientTrusted)
        return Success;
    if ((requested | allowed) == allowed)
        return Success;

    return BadAccess;
}

/*
 * Labels initial server objects.
 */
static void
SecurityLabelInitial(void)
{
    SecurityStateRec *state;

    /* Do the serverClient */
    state = dixLookupPrivate(&serverClient->devPrivates, stateKey);
    state->trustLevel = XSecurityClientTrusted;
    state->haveState = TRUE;
    state->live = FALSE;
}

/*
 * Looks up a request name
 */
static _X_INLINE const char *
SecurityLookupRequestName(ClientPtr client)
{
    return LookupRequestName(client->majorOp, client->minorOp);
}

/* SecurityDeleteAuthorization
 *
 * Arguments:
 *	value is the authorization to delete.
 *	id is its resource ID.
 *
 * Returns: Success.
 *
 * Side Effects:
 *	Frees everything associated with the authorization.
 */

static int
SecurityDeleteAuthorization(void *value, XID id)
{
    SecurityAuthorizationPtr pAuth = (SecurityAuthorizationPtr) value;
    unsigned short name_len, data_len;
    const char *name;
    char *data;
    int status;
    int i;
    OtherClientsPtr pEventClient;

    /* Remove the auth using the os layer auth manager */

    status = AuthorizationFromID(pAuth->id, &name_len, &name, &data_len, &data);
    assert(status);
    status = RemoveAuthorization(name_len, name, data_len, data);
    assert(status);
    (void) status;

    /* free the auth timer if there is one */

    if (pAuth->timer)
        TimerFree(pAuth->timer);

    /* send revoke events */

    while ((pEventClient = pAuth->eventClients)) {
        /* send revocation event event */
        xSecurityAuthorizationRevokedEvent are = {
            .type = SecurityEventBase + XSecurityAuthorizationRevoked,
            .authId = pAuth->id
        };
        WriteEventsToClient(rClient(pEventClient), 1, (xEvent *) &are);
        FreeResource(pEventClient->resource, RT_NONE);
    }

    /* kill all clients using this auth */

    for (i = 1; i < currentMaxClients; i++)
        if (clients[i]) {
            SecurityStateRec *state;

            state = dixLookupPrivate(&clients[i]->devPrivates, stateKey);
            if (state->haveState && state->authId == pAuth->id)
                CloseDownClient(clients[i]);
        }

    SecurityAudit("revoked authorization ID %lu\n", (unsigned long)pAuth->id);
    free(pAuth);
    return Success;

}                               /* SecurityDeleteAuthorization */

/* resource delete function for RTEventClient */
static int
SecurityDeleteAuthorizationEventClient(void *value, XID id)
{
    OtherClientsPtr pEventClient, prev = NULL;
    SecurityAuthorizationPtr pAuth = (SecurityAuthorizationPtr) value;

    for (pEventClient = pAuth->eventClients;
         pEventClient; pEventClient = pEventClient->next) {
        if (pEventClient->resource == id) {
            if (prev)
                prev->next = pEventClient->next;
            else
                pAuth->eventClients = pEventClient->next;
            free(pEventClient);
            return Success;
        }
        prev = pEventClient;
    }
     /*NOTREACHED*/ return -1;  /* make compiler happy */
}                               /* SecurityDeleteAuthorizationEventClient */

/* SecurityComputeAuthorizationTimeout
 *
 * Arguments:
 *	pAuth is the authorization for which we are computing the timeout
 *	seconds is the number of seconds we want to wait
 *
 * Returns:
 *	the number of milliseconds that the auth timer should be set to
 *
 * Side Effects:
 *	Sets pAuth->secondsRemaining to any "overflow" amount of time
 *	that didn't fit in 32 bits worth of milliseconds
 */

static CARD32
SecurityComputeAuthorizationTimeout(SecurityAuthorizationPtr pAuth,
                                    unsigned int seconds)
{
    /* maxSecs is the number of full seconds that can be expressed in
     * 32 bits worth of milliseconds
     */
    CARD32 maxSecs = (CARD32) (~0) / (CARD32) MILLI_PER_SECOND;

    if (seconds > maxSecs) {    /* only come here if we want to wait more than 49 days */
        pAuth->secondsRemaining = seconds - maxSecs;
        return maxSecs * MILLI_PER_SECOND;
    }
    else {                      /* by far the common case */
        pAuth->secondsRemaining = 0;
        return seconds * MILLI_PER_SECOND;
    }
}                               /* SecurityStartAuthorizationTimer */

/* SecurityAuthorizationExpired
 *
 * This function is passed as an argument to TimerSet and gets called from
 * the timer manager in the os layer when its time is up.
 *
 * Arguments:
 *	timer is the timer for this authorization.
 *	time is the current time.
 *	pval is the authorization whose time is up.
 *
 * Returns:
 *	A new time delay in milliseconds if the timer should wait some
 *	more, else zero.
 *
 * Side Effects:
 *	Frees the authorization resource if the timeout period is really
 *	over, otherwise recomputes pAuth->secondsRemaining.
 */

static CARD32
SecurityAuthorizationExpired(OsTimerPtr timer, CARD32 time, void *pval)
{
    SecurityAuthorizationPtr pAuth = (SecurityAuthorizationPtr) pval;

    assert(pAuth->timer == timer);

    if (pAuth->secondsRemaining) {
        return SecurityComputeAuthorizationTimeout(pAuth,
                                                   pAuth->secondsRemaining);
    }
    else {
        FreeResource(pAuth->id, RT_NONE);
        return 0;
    }
}                               /* SecurityAuthorizationExpired */

/* SecurityStartAuthorizationTimer
 *
 * Arguments:
 *	pAuth is the authorization whose timer should be started.
 *
 * Returns: nothing.
 *
 * Side Effects:
 *	A timer is started, set to expire after the timeout period for
 *	this authorization.  When it expires, the function
 *	SecurityAuthorizationExpired will be called.
 */

static void
SecurityStartAuthorizationTimer(SecurityAuthorizationPtr pAuth)
{
    pAuth->timer = TimerSet(pAuth->timer, 0,
                            SecurityComputeAuthorizationTimeout(pAuth,
                                                                pAuth->timeout),
                            SecurityAuthorizationExpired, pAuth);
}                               /* SecurityStartAuthorizationTimer */

/* Proc functions all take a client argument, execute the request in
 * client->requestBuffer, and return a protocol error status.
 */

static int
ProcSecurityQueryVersion(ClientPtr client)
{
    /* REQUEST(xSecurityQueryVersionReq); */
    xSecurityQueryVersionReply rep = {
        .type = X_Reply,
        .sequenceNumber = client->sequence,
        .length = 0,
        .majorVersion = SERVER_SECURITY_MAJOR_VERSION,
        .minorVersion = SERVER_SECURITY_MINOR_VERSION
    };

    REQUEST_SIZE_MATCH(xSecurityQueryVersionReq);

    if (client->swapped) {
        swaps(&rep.sequenceNumber);
        swaps(&rep.majorVersion);
        swaps(&rep.minorVersion);
    }
    WriteToClient(client, SIZEOF(xSecurityQueryVersionReply), &rep);
    return Success;
}                               /* ProcSecurityQueryVersion */

static int
SecurityEventSelectForAuthorization(SecurityAuthorizationPtr pAuth,
                                    ClientPtr client, Mask mask)
{
    OtherClients *pEventClient;

    for (pEventClient = pAuth->eventClients;
         pEventClient; pEventClient = pEventClient->next) {
        if (SameClient(pEventClient, client)) {
            if (mask == 0)
                FreeResource(pEventClient->resource, RT_NONE);
            else
                pEventClient->mask = mask;
            return Success;
        }
    }

    pEventClient = malloc(sizeof(OtherClients));
    if (!pEventClient)
        return BadAlloc;
    pEventClient->mask = mask;
    pEventClient->resource = FakeClientID(client->index);
    pEventClient->next = pAuth->eventClients;
    if (!AddResource(pEventClient->resource, RTEventClient, (void *) pAuth)) {
        free(pEventClient);
        return BadAlloc;
    }
    pAuth->eventClients = pEventClient;

    return Success;
}                               /* SecurityEventSelectForAuthorization */

static int
ProcSecurityGenerateAuthorization(ClientPtr client)
{
    REQUEST(xSecurityGenerateAuthorizationReq);
    int len;                    /* request length in CARD32s */
    Bool removeAuth = FALSE;    /* if bailout, call RemoveAuthorization? */
    SecurityAuthorizationPtr pAuth = NULL;      /* auth we are creating */
    int err;                    /* error to return from this function */
    XID authId;                 /* authorization ID assigned by os layer */
    xSecurityGenerateAuthorizationReply rep;    /* reply struct */
    unsigned int trustLevel;    /* trust level of new auth */
    XID group;                  /* group of new auth */
    CARD32 timeout;             /* timeout of new auth */
    CARD32 *values;             /* list of supplied attributes */
    char *protoname;            /* auth proto name sent in request */
    char *protodata;            /* auth proto data sent in request */
    unsigned int authdata_len;  /* # bytes of generated auth data */
    char *pAuthdata;            /* generated auth data */
    Mask eventMask;             /* what events on this auth does client want */

    /* check request length */

    REQUEST_AT_LEAST_SIZE(xSecurityGenerateAuthorizationReq);
    len = bytes_to_int32(SIZEOF(xSecurityGenerateAuthorizationReq));
    len += bytes_to_int32(stuff->nbytesAuthProto);
    len += bytes_to_int32(stuff->nbytesAuthData);
    values = ((CARD32 *) stuff) + len;
    len += Ones(stuff->valueMask);
    if (client->req_len != len)
        return BadLength;

    /* check valuemask */
    if (stuff->valueMask & ~XSecurityAllAuthorizationAttributes) {
        client->errorValue = stuff->valueMask;
        return BadValue;
    }

    /* check timeout */
    timeout = 60;
    if (stuff->valueMask & XSecurityTimeout) {
        timeout = *values++;
    }

    /* check trustLevel */
    trustLevel = XSecurityClientUntrusted;
    if (stuff->valueMask & XSecurityTrustLevel) {
        trustLevel = *values++;
        if (trustLevel != XSecurityClientTrusted &&
            trustLevel != XSecurityClientUntrusted) {
            client->errorValue = trustLevel;
            return BadValue;
        }
    }

    /* check group */
    group = None;
    if (stuff->valueMask & XSecurityGroup) {
        group = *values++;
        if (SecurityValidateGroupCallback) {
            SecurityValidateGroupInfoRec vgi;

            vgi.group = group;
            vgi.valid = FALSE;
            CallCallbacks(&SecurityValidateGroupCallback, (void *) &vgi);

            /* if nobody said they recognized it, it's an error */

            if (!vgi.valid) {
                client->errorValue = group;
                return BadValue;
            }
        }
    }

    /* check event mask */
    eventMask = 0;
    if (stuff->valueMask & XSecurityEventMask) {
        eventMask = *values++;
        if (eventMask & ~XSecurityAllEventMasks) {
            client->errorValue = eventMask;
            return BadValue;
        }
    }

    protoname = (char *) &stuff[1];
    protodata = protoname + bytes_to_int32(stuff->nbytesAuthProto);

    /* call os layer to generate the authorization */

    authId = GenerateAuthorization(stuff->nbytesAuthProto, protoname,
                                   stuff->nbytesAuthData, protodata,
                                   &authdata_len, &pAuthdata);
    if ((XID) ~0L == authId) {
        err = SecurityErrorBase + XSecurityBadAuthorizationProtocol;
        goto bailout;
    }

    /* now that we've added the auth, remember to remove it if we have to
     * abort the request for some reason (like allocation failure)
     */
    removeAuth = TRUE;

    /* associate additional information with this auth ID */

    pAuth = malloc(sizeof(SecurityAuthorizationRec));
    if (!pAuth) {
        err = BadAlloc;
        goto bailout;
    }

    /* fill in the auth fields */

    pAuth->id = authId;
    pAuth->timeout = timeout;
    pAuth->group = group;
    pAuth->trustLevel = trustLevel;
    pAuth->refcnt = 0;          /* the auth was just created; nobody's using it yet */
    pAuth->secondsRemaining = 0;
    pAuth->timer = NULL;
    pAuth->eventClients = NULL;

    /* handle event selection */
    if (eventMask) {
        err = SecurityEventSelectForAuthorization(pAuth, client, eventMask);
        if (err != Success)
            goto bailout;
    }

    if (!AddResource(authId, SecurityAuthorizationResType, pAuth)) {
        err = BadAlloc;
        goto bailout;
    }

    /* start the timer ticking */

    if (pAuth->timeout != 0)
        SecurityStartAuthorizationTimer(pAuth);

    /* tell client the auth id and data */

    rep = (xSecurityGenerateAuthorizationReply) {
        .type = X_Reply,
        .sequenceNumber = client->sequence,
        .length = bytes_to_int32(authdata_len),
        .authId = authId,
        .dataLength = authdata_len
    };

    if (client->swapped) {
        swapl(&rep.length);
        swaps(&rep.sequenceNumber);
        swapl(&rep.authId);
        swaps(&rep.dataLength);
    }

    WriteToClient(client, SIZEOF(xSecurityGenerateAuthorizationReply), &rep);
    WriteToClient(client, authdata_len, pAuthdata);

    SecurityAudit
        ("client %d generated authorization %lu trust %d timeout %lu group %lu events %lu\n",
         client->index, (unsigned long)pAuth->id, pAuth->trustLevel, (unsigned long)pAuth->timeout,
         (unsigned long)pAuth->group, (unsigned long)eventMask);

    /* the request succeeded; don't call RemoveAuthorization or free pAuth */
    return Success;

 bailout:
    if (removeAuth)
        RemoveAuthorization(stuff->nbytesAuthProto, protoname,
                            authdata_len, pAuthdata);
    free(pAuth);
    return err;

}                               /* ProcSecurityGenerateAuthorization */

static int
ProcSecurityRevokeAuthorization(ClientPtr client)
{
    REQUEST(xSecurityRevokeAuthorizationReq);
    SecurityAuthorizationPtr pAuth;
    int rc;

    REQUEST_SIZE_MATCH(xSecurityRevokeAuthorizationReq);

    rc = dixLookupResourceByType((void **) &pAuth, stuff->authId,
                                 SecurityAuthorizationResType, client,
                                 DixDestroyAccess);
    if (rc != Success)
        return rc;

    FreeResource(stuff->authId, RT_NONE);
    return Success;
}                               /* ProcSecurityRevokeAuthorization */

static int
ProcSecurityDispatch(ClientPtr client)
{
    REQUEST(xReq);

    switch (stuff->data) {
    case X_SecurityQueryVersion:
        return ProcSecurityQueryVersion(client);
    case X_SecurityGenerateAuthorization:
        return ProcSecurityGenerateAuthorization(client);
    case X_SecurityRevokeAuthorization:
        return ProcSecurityRevokeAuthorization(client);
    default:
        return BadRequest;
    }
}                               /* ProcSecurityDispatch */

static int _X_COLD
SProcSecurityQueryVersion(ClientPtr client)
{
    REQUEST(xSecurityQueryVersionReq);

    swaps(&stuff->length);
    REQUEST_SIZE_MATCH(xSecurityQueryVersionReq);
    swaps(&stuff->majorVersion);
    swaps(&stuff->minorVersion);
    return ProcSecurityQueryVersion(client);
}                               /* SProcSecurityQueryVersion */

static int _X_COLD
SProcSecurityGenerateAuthorization(ClientPtr client)
{
    REQUEST(xSecurityGenerateAuthorizationReq);
    CARD32 *values;
    unsigned long nvalues;
    int values_offset;

    swaps(&stuff->length);
    REQUEST_AT_LEAST_SIZE(xSecurityGenerateAuthorizationReq);
    swaps(&stuff->nbytesAuthProto);
    swaps(&stuff->nbytesAuthData);
    swapl(&stuff->valueMask);
    values_offset = bytes_to_int32(stuff->nbytesAuthProto) +
        bytes_to_int32(stuff->nbytesAuthData);
    if (values_offset >
        stuff->length - bytes_to_int32(sz_xSecurityGenerateAuthorizationReq))
        return BadLength;
    values = (CARD32 *) (&stuff[1]) + values_offset;
    nvalues = (((CARD32 *) stuff) + stuff->length) - values;
    SwapLongs(values, nvalues);
    return ProcSecurityGenerateAuthorization(client);
}                               /* SProcSecurityGenerateAuthorization */

static int _X_COLD
SProcSecurityRevokeAuthorization(ClientPtr client)
{
    REQUEST(xSecurityRevokeAuthorizationReq);

    swaps(&stuff->length);
    REQUEST_SIZE_MATCH(xSecurityRevokeAuthorizationReq);
    swapl(&stuff->authId);
    return ProcSecurityRevokeAuthorization(client);
}                               /* SProcSecurityRevokeAuthorization */

static int _X_COLD
SProcSecurityDispatch(ClientPtr client)
{
    REQUEST(xReq);

    switch (stuff->data) {
    case X_SecurityQueryVersion:
        return SProcSecurityQueryVersion(client);
    case X_SecurityGenerateAuthorization:
        return SProcSecurityGenerateAuthorization(client);
    case X_SecurityRevokeAuthorization:
        return SProcSecurityRevokeAuthorization(client);
    default:
        return BadRequest;
    }
}                               /* SProcSecurityDispatch */

static void _X_COLD
SwapSecurityAuthorizationRevokedEvent(xSecurityAuthorizationRevokedEvent * from,
                                      xSecurityAuthorizationRevokedEvent * to)
{
    to->type = from->type;
    to->detail = from->detail;
    cpswaps(from->sequenceNumber, to->sequenceNumber);
    cpswapl(from->authId, to->authId);
}

/* SecurityCheckDeviceAccess
 *
 * Arguments:
 *	client is the client attempting to access a device.
 *	dev is the device being accessed.
 *	fromRequest is TRUE if the device access is a direct result of
 *	  the client executing some request and FALSE if it is a
 *	  result of the server trying to send an event (e.g. KeymapNotify)
 *	  to the client.
 * Returns:
 *	TRUE if the device access should be allowed, else FALSE.
 *
 * Side Effects:
 *	An audit message is generated if access is denied.
 */

static void
SecurityDevice(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    XaceDeviceAccessRec *rec = calldata;
    SecurityStateRec *subj, *obj;
    Mask requested = rec->access_mode;
    Mask allowed = SecurityDeviceMask;

    subj = dixLookupPrivate(&rec->client->devPrivates, stateKey);
    obj = dixLookupPrivate(&serverClient->devPrivates, stateKey);

    if (rec->dev != inputInfo.keyboard)
        /* this extension only supports the core keyboard */
        allowed = requested;

    if (SecurityDoCheck(subj, obj, requested, allowed) != Success) {
        SecurityAudit("Security denied client %d keyboard access on request "
                      "%s\n", rec->client->index,
                      SecurityLookupRequestName(rec->client));
        rec->status = BadAccess;
    }
}

/* SecurityResource
 *
 * This function gets plugged into client->CheckAccess and is called from
 * SecurityLookupIDByType/Class to determine if the client can access the
 * resource.
 *
 * Arguments:
 *	client is the client doing the resource access.
 *	id is the resource id.
 *	rtype is its type or class.
 *	access_mode represents the intended use of the resource; see
 *	  resource.h.
 *	res is a pointer to the resource structure for this resource.
 *
 * Returns:
 *	If access is granted, the value of rval that was passed in, else FALSE.
 *
 * Side Effects:
 *	Disallowed resource accesses are audited.
 */

static void
SecurityResource(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    XaceResourceAccessRec *rec = calldata;
    SecurityStateRec *subj, *obj;
    int cid = CLIENT_ID(rec->id);
    Mask requested = rec->access_mode;
    Mask allowed = SecurityResourceMask;

    subj = dixLookupPrivate(&rec->client->devPrivates, stateKey);

    /* disable background None for untrusted windows */
    if ((requested & DixCreateAccess) && (rec->rtype == RT_WINDOW))
        if (subj->haveState && subj->trustLevel != XSecurityClientTrusted)
            ((WindowPtr) rec->res)->forcedBG = TRUE;

    /* additional permissions for specific resource types */
    if (rec->rtype == RT_WINDOW)
        allowed |= SecurityWindowExtraMask;

    /* special checks for server-owned resources */
    if (cid == 0) {
        if (rec->rtype & RC_DRAWABLE)
            /* additional operations allowed on root windows */
            allowed |= SecurityRootWindowExtraMask;

        else if (rec->rtype == RT_COLORMAP)
            /* allow access to default colormaps */
            allowed = requested;

        else
            /* allow read access to other server-owned resources */
            allowed |= DixReadAccess;
    }

    if (clients[cid] != NULL) {
        obj = dixLookupPrivate(&clients[cid]->devPrivates, stateKey);
        if (SecurityDoCheck(subj, obj, requested, allowed) == Success)
            return;
    }

    SecurityAudit("Security: denied client %d access %lx to resource 0x%lx "
                  "of client %d on request %s\n", rec->client->index,
                  (unsigned long)requested, (unsigned long)rec->id, cid,
                  SecurityLookupRequestName(rec->client));
    rec->status = BadAccess;    /* deny access */
}

static void
SecurityExtension(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    XaceExtAccessRec *rec = calldata;
    SecurityStateRec *subj;
    int i = 0;

    subj = dixLookupPrivate(&rec->client->devPrivates, stateKey);

    if (subj->haveState && subj->trustLevel == XSecurityClientTrusted)
        return;

    while (SecurityTrustedExtensions[i])
        if (!strcmp(SecurityTrustedExtensions[i++], rec->ext->name))
            return;

    SecurityAudit("Security: denied client %d access to extension "
                  "%s on request %s\n",
                  rec->client->index, rec->ext->name,
                  SecurityLookupRequestName(rec->client));
    rec->status = BadAccess;
}

static void
SecurityServer(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    XaceServerAccessRec *rec = calldata;
    SecurityStateRec *subj, *obj;
    Mask requested = rec->access_mode;
    Mask allowed = SecurityServerMask;

    subj = dixLookupPrivate(&rec->client->devPrivates, stateKey);
    obj = dixLookupPrivate(&serverClient->devPrivates, stateKey);

    if (SecurityDoCheck(subj, obj, requested, allowed) != Success) {
        SecurityAudit("Security: denied client %d access to server "
                      "configuration request %s\n", rec->client->index,
                      SecurityLookupRequestName(rec->client));
        rec->status = BadAccess;
    }
}

static void
SecurityClient(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    XaceClientAccessRec *rec = calldata;
    SecurityStateRec *subj, *obj;
    Mask requested = rec->access_mode;
    Mask allowed = SecurityClientMask;

    subj = dixLookupPrivate(&rec->client->devPrivates, stateKey);
    obj = dixLookupPrivate(&rec->target->devPrivates, stateKey);

    if (SecurityDoCheck(subj, obj, requested, allowed) != Success) {
        SecurityAudit("Security: denied client %d access to client %d on "
                      "request %s\n", rec->client->index, rec->target->index,
                      SecurityLookupRequestName(rec->client));
        rec->status = BadAccess;
    }
}

static void
SecurityProperty(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    XacePropertyAccessRec *rec = calldata;
    SecurityStateRec *subj, *obj;
    ATOM name = (*rec->ppProp)->propertyName;
    Mask requested = rec->access_mode;
    Mask allowed = SecurityResourceMask | DixReadAccess;

    subj = dixLookupPrivate(&rec->client->devPrivates, stateKey);
    obj = dixLookupPrivate(&wClient(rec->pWin)->devPrivates, stateKey);

    if (SecurityDoCheck(subj, obj, requested, allowed) != Success) {
        SecurityAudit("Security: denied client %d access to property %s "
                      "(atom 0x%x) window 0x%lx of client %d on request %s\n",
                      rec->client->index, NameForAtom(name), name,
                      (unsigned long)rec->pWin->drawable.id, wClient(rec->pWin)->index,
                      SecurityLookupRequestName(rec->client));
        rec->status = BadAccess;
    }
}

static void
SecuritySend(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    XaceSendAccessRec *rec = calldata;
    SecurityStateRec *subj, *obj;

    if (rec->client) {
        int i;

        subj = dixLookupPrivate(&rec->client->devPrivates, stateKey);
        obj = dixLookupPrivate(&wClient(rec->pWin)->devPrivates, stateKey);

        if (SecurityDoCheck(subj, obj, DixSendAccess, 0) == Success)
            return;

        for (i = 0; i < rec->count; i++)
            if (rec->events[i].u.u.type != UnmapNotify &&
                rec->events[i].u.u.type != ConfigureRequest &&
                rec->events[i].u.u.type != ClientMessage) {

                SecurityAudit("Security: denied client %d from sending event "
                              "of type %s to window 0x%lx of client %d\n",
                              rec->client->index,
                              LookupEventName(rec->events[i].u.u.type),
                              (unsigned long)rec->pWin->drawable.id,
                              wClient(rec->pWin)->index);
                rec->status = BadAccess;
                return;
            }
    }
}

static void
SecurityReceive(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    XaceReceiveAccessRec *rec = calldata;
    SecurityStateRec *subj, *obj;

    subj = dixLookupPrivate(&rec->client->devPrivates, stateKey);
    obj = dixLookupPrivate(&wClient(rec->pWin)->devPrivates, stateKey);

    if (SecurityDoCheck(subj, obj, DixReceiveAccess, 0) == Success)
        return;

    SecurityAudit("Security: denied client %d from receiving an event "
                  "sent to window 0x%lx of client %d\n",
                  rec->client->index, (unsigned long)rec->pWin->drawable.id,
                  wClient(rec->pWin)->index);
    rec->status = BadAccess;
}

/* SecurityClientStateCallback
 *
 * Arguments:
 *	pcbl is &ClientStateCallback.
 *	nullata is NULL.
 *	calldata is a pointer to a NewClientInfoRec (include/dixstruct.h)
 *	which contains information about client state changes.
 *
 * Returns: nothing.
 *
 * Side Effects:
 *
 * If a new client is connecting, its authorization ID is copied to
 * client->authID.  If this is a generated authorization, its reference
 * count is bumped, its timer is cancelled if it was running, and its
 * trustlevel is copied to TRUSTLEVEL(client).
 *
 * If a client is disconnecting and the client was using a generated
 * authorization, the authorization's reference count is decremented, and
 * if it is now zero, the timer for this authorization is started.
 */

static void
SecurityClientState(CallbackListPtr *pcbl, void *unused, void *calldata)
{
    NewClientInfoRec *pci = calldata;
    SecurityStateRec *state;
    SecurityAuthorizationPtr pAuth;
    int rc;

    state = dixLookupPrivate(&pci->client->devPrivates, stateKey);

    switch (pci->client->clientState) {
    case ClientStateInitial:
        state->trustLevel = XSecurityClientTrusted;
        state->authId = None;
        state->haveState = TRUE;
        state->live = FALSE;
        break;

    case ClientStateRunning:
        state->authId = AuthorizationIDOfClient(pci->client);
        rc = dixLookupResourceByType((void **) &pAuth, state->authId,
                                     SecurityAuthorizationResType, serverClient,
                                     DixGetAttrAccess);
        if (rc == Success) {
            /* it is a generated authorization */
            pAuth->refcnt++;
            state->live = TRUE;
            if (pAuth->refcnt == 1 && pAuth->timer)
                TimerCancel(pAuth->timer);

            state->trustLevel = pAuth->trustLevel;
        }
        break;

    case ClientStateGone:
    case ClientStateRetained:
        rc = dixLookupResourceByType((void **) &pAuth, state->authId,
                                     SecurityAuthorizationResType, serverClient,
                                     DixGetAttrAccess);
        if (rc == Success && state->live) {
            /* it is a generated authorization */
            pAuth->refcnt--;
            state->live = FALSE;
            if (pAuth->refcnt == 0)
                SecurityStartAuthorizationTimer(pAuth);
        }
        break;

    default:
        break;
    }
}

/* SecurityResetProc
 *
 * Arguments:
 *	extEntry is the extension information for the security extension.
 *
 * Returns: nothing.
 *
 * Side Effects:
 *	Performs any cleanup needed by Security at server shutdown time.
 */

static void
SecurityResetProc(ExtensionEntry * extEntry)
{
    /* Unregister callbacks */
    DeleteCallback(&ClientStateCallback, SecurityClientState, NULL);

    XaceDeleteCallback(XACE_EXT_DISPATCH, SecurityExtension, NULL);
    XaceDeleteCallback(XACE_RESOURCE_ACCESS, SecurityResource, NULL);
    XaceDeleteCallback(XACE_DEVICE_ACCESS, SecurityDevice, NULL);
    XaceDeleteCallback(XACE_PROPERTY_ACCESS, SecurityProperty, NULL);
    XaceDeleteCallback(XACE_SEND_ACCESS, SecuritySend, NULL);
    XaceDeleteCallback(XACE_RECEIVE_ACCESS, SecurityReceive, NULL);
    XaceDeleteCallback(XACE_CLIENT_ACCESS, SecurityClient, NULL);
    XaceDeleteCallback(XACE_EXT_ACCESS, SecurityExtension, NULL);
    XaceDeleteCallback(XACE_SERVER_ACCESS, SecurityServer, NULL);
}

/* SecurityExtensionInit
 *
 * Arguments: none.
 *
 * Returns: nothing.
 *
 * Side Effects:
 *	Enables the Security extension if possible.
 */

void
SecurityExtensionInit(void)
{
    ExtensionEntry *extEntry;
    int ret = TRUE;

    SecurityAuthorizationResType =
        CreateNewResourceType(SecurityDeleteAuthorization,
                              "SecurityAuthorization");

    RTEventClient =
        CreateNewResourceType(SecurityDeleteAuthorizationEventClient,
                              "SecurityEventClient");

    if (!SecurityAuthorizationResType || !RTEventClient)
        return;

    RTEventClient |= RC_NEVERRETAIN;

    /* Allocate the private storage */
    if (!dixRegisterPrivateKey
        (stateKey, PRIVATE_CLIENT, sizeof(SecurityStateRec)))
        FatalError("SecurityExtensionSetup: Can't allocate client private.\n");

    /* Register callbacks */
    ret &= AddCallback(&ClientStateCallback, SecurityClientState, NULL);

    ret &= XaceRegisterCallback(XACE_EXT_DISPATCH, SecurityExtension, NULL);
    ret &= XaceRegisterCallback(XACE_RESOURCE_ACCESS, SecurityResource, NULL);
    ret &= XaceRegisterCallback(XACE_DEVICE_ACCESS, SecurityDevice, NULL);
    ret &= XaceRegisterCallback(XACE_PROPERTY_ACCESS, SecurityProperty, NULL);
    ret &= XaceRegisterCallback(XACE_SEND_ACCESS, SecuritySend, NULL);
    ret &= XaceRegisterCallback(XACE_RECEIVE_ACCESS, SecurityReceive, NULL);
    ret &= XaceRegisterCallback(XACE_CLIENT_ACCESS, SecurityClient, NULL);
    ret &= XaceRegisterCallback(XACE_EXT_ACCESS, SecurityExtension, NULL);
    ret &= XaceRegisterCallback(XACE_SERVER_ACCESS, SecurityServer, NULL);

    if (!ret)
        FatalError("SecurityExtensionSetup: Failed to register callbacks\n");

    /* Add extension to server */
    extEntry = AddExtension(SECURITY_EXTENSION_NAME,
                            XSecurityNumberEvents, XSecurityNumberErrors,
                            ProcSecurityDispatch, SProcSecurityDispatch,
                            SecurityResetProc, StandardMinorOpcode);

    SecurityErrorBase = extEntry->errorBase;
    SecurityEventBase = extEntry->eventBase;

    EventSwapVector[SecurityEventBase + XSecurityAuthorizationRevoked] =
        (EventSwapPtr) SwapSecurityAuthorizationRevokedEvent;

    SetResourceTypeErrorValue(SecurityAuthorizationResType,
                              SecurityErrorBase + XSecurityBadAuthorization);

    /* Label objects that were created before we could register ourself */
    SecurityLabelInitial();
}