summaryrefslogtreecommitdiffstats
path: root/security/nss/lib/pk11wrap/pk11cxt.c
blob: e9726d03cf93724ecf855c423aff87ca3ffb9ef4 (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
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
 * This file PK11Contexts which are  used in multipart hashing,
 * encryption/decryption, and signing/verication operations.
 */

#include "seccomon.h"
#include "secmod.h"
#include "nssilock.h"
#include "secmodi.h"
#include "secmodti.h"
#include "pkcs11.h"
#include "pk11func.h"
#include "secitem.h"
#include "secoid.h"
#include "sechash.h"
#include "secerr.h"

static const SECItem pk11_null_params = { 0 };

/**********************************************************************
 *
 *                   Now Deal with Crypto Contexts
 *
 **********************************************************************/

/*
 * the monitors...
 */
void
PK11_EnterContextMonitor(PK11Context *cx)
{
    /* if we own the session and our slot is ThreadSafe, only monitor
     * the Context */
    if ((cx->ownSession) && (cx->slot->isThreadSafe)) {
        /* Should this use monitors instead? */
        PZ_Lock(cx->sessionLock);
    } else {
        PK11_EnterSlotMonitor(cx->slot);
    }
}

void
PK11_ExitContextMonitor(PK11Context *cx)
{
    /* if we own the session and our slot is ThreadSafe, only monitor
     * the Context */
    if ((cx->ownSession) && (cx->slot->isThreadSafe)) {
        /* Should this use monitors instead? */
        PZ_Unlock(cx->sessionLock);
    } else {
        PK11_ExitSlotMonitor(cx->slot);
    }
}

/*
 * Free up a Cipher Context
 */
void
PK11_DestroyContext(PK11Context *context, PRBool freeit)
{
    pk11_CloseSession(context->slot, context->session, context->ownSession);
    /* initialize the critical fields of the context */
    if (context->savedData != NULL)
        PORT_Free(context->savedData);
    if (context->key)
        PK11_FreeSymKey(context->key);
    if (context->param && context->param != &pk11_null_params)
        SECITEM_FreeItem(context->param, PR_TRUE);
    if (context->sessionLock)
        PZ_DestroyLock(context->sessionLock);
    PK11_FreeSlot(context->slot);
    if (freeit)
        PORT_Free(context);
}

/*
 * save the current context. Allocate Space if necessary.
 */
static unsigned char *
pk11_saveContextHelper(PK11Context *context, unsigned char *buffer,
                       unsigned long *savedLength)
{
    CK_RV crv;

    /* If buffer is NULL, this will get the length */
    crv = PK11_GETTAB(context->slot)->C_GetOperationState(context->session, (CK_BYTE_PTR)buffer, savedLength);
    if (!buffer || (crv == CKR_BUFFER_TOO_SMALL)) {
        /* the given buffer wasn't big enough (or was NULL), but we
         * have the length, so try again with a new buffer and the
         * correct length
         */
        unsigned long bufLen = *savedLength;
        buffer = PORT_Alloc(bufLen);
        if (buffer == NULL) {
            return (unsigned char *)NULL;
        }
        crv = PK11_GETTAB(context->slot)->C_GetOperationState(context->session, (CK_BYTE_PTR)buffer, savedLength);
        if (crv != CKR_OK) {
            PORT_ZFree(buffer, bufLen);
        }
    }
    if (crv != CKR_OK) {
        PORT_SetError(PK11_MapError(crv));
        return (unsigned char *)NULL;
    }
    return buffer;
}

void *
pk11_saveContext(PK11Context *context, void *space, unsigned long *savedLength)
{
    return pk11_saveContextHelper(context,
                                  (unsigned char *)space, savedLength);
}

/*
 * restore the current context
 */
SECStatus
pk11_restoreContext(PK11Context *context, void *space, unsigned long savedLength)
{
    CK_RV crv;
    CK_OBJECT_HANDLE objectID = (context->key) ? context->key->objectID : CK_INVALID_HANDLE;

    PORT_Assert(space != NULL);
    if (space == NULL) {
        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
        return SECFailure;
    }
    crv = PK11_GETTAB(context->slot)->C_SetOperationState(context->session, (CK_BYTE_PTR)space, savedLength, objectID, 0);
    if (crv != CKR_OK) {
        PORT_SetError(PK11_MapError(crv));
        return SECFailure;
    }
    return SECSuccess;
}

SECStatus pk11_Finalize(PK11Context *context);

/*
 * Context initialization. Used by all flavors of CreateContext
 */
static SECStatus
pk11_context_init(PK11Context *context, CK_MECHANISM *mech_info)
{
    CK_RV crv;
    PK11SymKey *symKey = context->key;
    SECStatus rv = SECSuccess;

    switch (context->operation) {
        case CKA_ENCRYPT:
            crv = PK11_GETTAB(context->slot)->C_EncryptInit(context->session, mech_info, symKey->objectID);
            break;
        case CKA_DECRYPT:
            if (context->fortezzaHack) {
                CK_ULONG count = 0;
                /* generate the IV for fortezza */
                crv = PK11_GETTAB(context->slot)->C_EncryptInit(context->session, mech_info, symKey->objectID);
                if (crv != CKR_OK)
                    break;
                PK11_GETTAB(context->slot)
                    ->C_EncryptFinal(context->session,
                                     NULL, &count);
            }
            crv = PK11_GETTAB(context->slot)->C_DecryptInit(context->session, mech_info, symKey->objectID);
            break;
        case CKA_SIGN:
            crv = PK11_GETTAB(context->slot)->C_SignInit(context->session, mech_info, symKey->objectID);
            break;
        case CKA_VERIFY:
            crv = PK11_GETTAB(context->slot)->C_SignInit(context->session, mech_info, symKey->objectID);
            break;
        case CKA_DIGEST:
            crv = PK11_GETTAB(context->slot)->C_DigestInit(context->session, mech_info);
            break;
        default:
            crv = CKR_OPERATION_NOT_INITIALIZED;
            break;
    }

    if (crv != CKR_OK) {
        PORT_SetError(PK11_MapError(crv));
        return SECFailure;
    }

    /*
     * handle session starvation case.. use our last session to multiplex
     */
    if (!context->ownSession) {
        context->savedData = pk11_saveContext(context, context->savedData,
                                              &context->savedLength);
        if (context->savedData == NULL)
            rv = SECFailure;
        /* clear out out session for others to use */
        pk11_Finalize(context);
    }
    return rv;
}

/*
 * Common Helper Function do come up with a new context.
 */
static PK11Context *
pk11_CreateNewContextInSlot(CK_MECHANISM_TYPE type,
                            PK11SlotInfo *slot, CK_ATTRIBUTE_TYPE operation, PK11SymKey *symKey,
                            SECItem *param)
{
    CK_MECHANISM mech_info;
    PK11Context *context;
    SECStatus rv;

    PORT_Assert(slot != NULL);
    if (!slot || (!symKey && ((operation != CKA_DIGEST) ||
                              (type == CKM_SKIPJACK_CBC64)))) {
        PORT_SetError(SEC_ERROR_INVALID_ARGS);
        return NULL;
    }
    context = (PK11Context *)PORT_Alloc(sizeof(PK11Context));
    if (context == NULL) {
        return NULL;
    }

    /* now deal with the fortezza hack... the fortezza hack is an attempt
     * to get around the issue of the card not allowing you to do a FORTEZZA
     * LoadIV/Encrypt, which was added because such a combination could be
     * use to circumvent the key escrow system. Unfortunately SSL needs to
     * do this kind of operation, so in SSL we do a loadIV (to verify it),
     * Then GenerateIV, and through away the first 8 bytes on either side
     * of the connection.*/
    context->fortezzaHack = PR_FALSE;
    if (type == CKM_SKIPJACK_CBC64) {
        if (symKey->origin == PK11_OriginFortezzaHack) {
            context->fortezzaHack = PR_TRUE;
        }
    }

    /* initialize the critical fields of the context */
    context->operation = operation;
    context->key = symKey ? PK11_ReferenceSymKey(symKey) : NULL;
    context->slot = PK11_ReferenceSlot(slot);
    context->session = pk11_GetNewSession(slot, &context->ownSession);
    context->cx = symKey ? symKey->cx : NULL;
    /* get our session */
    context->savedData = NULL;

    /* save the parameters so that some digesting stuff can do multiple
     * begins on a single context */
    context->type = type;
    if (param) {
        if (param->len > 0) {
            context->param = SECITEM_DupItem(param);
        } else {
            context->param = (SECItem *)&pk11_null_params;
        }
    } else {
        PORT_SetError(SEC_ERROR_INVALID_ARGS);
        context->param = NULL;
    }
    context->init = PR_FALSE;
    context->sessionLock = PZ_NewLock(nssILockPK11cxt);
    if ((context->param == NULL) || (context->sessionLock == NULL)) {
        PK11_DestroyContext(context, PR_TRUE);
        return NULL;
    }

    mech_info.mechanism = type;
    mech_info.pParameter = param->data;
    mech_info.ulParameterLen = param->len;
    PK11_EnterContextMonitor(context);
    rv = pk11_context_init(context, &mech_info);
    PK11_ExitContextMonitor(context);

    if (rv != SECSuccess) {
        PK11_DestroyContext(context, PR_TRUE);
        return NULL;
    }
    context->init = PR_TRUE;
    return context;
}

/*
 * put together the various PK11_Create_Context calls used by different
 * parts of libsec.
 */
PK11Context *
__PK11_CreateContextByRawKey(PK11SlotInfo *slot, CK_MECHANISM_TYPE type,
                             PK11Origin origin, CK_ATTRIBUTE_TYPE operation, SECItem *key,
                             SECItem *param, void *wincx)
{
    PK11SymKey *symKey = NULL;
    PK11Context *context = NULL;

    /* first get a slot */
    if (slot == NULL) {
        slot = PK11_GetBestSlot(type, wincx);
        if (slot == NULL) {
            PORT_SetError(SEC_ERROR_NO_MODULE);
            goto loser;
        }
    } else {
        PK11_ReferenceSlot(slot);
    }

    /* now import the key */
    symKey = PK11_ImportSymKey(slot, type, origin, operation, key, wincx);
    if (symKey == NULL)
        goto loser;

    context = PK11_CreateContextBySymKey(type, operation, symKey, param);

loser:
    if (symKey) {
        PK11_FreeSymKey(symKey);
    }
    if (slot) {
        PK11_FreeSlot(slot);
    }

    return context;
}

PK11Context *
PK11_CreateContextByRawKey(PK11SlotInfo *slot, CK_MECHANISM_TYPE type,
                           PK11Origin origin, CK_ATTRIBUTE_TYPE operation, SECItem *key,
                           SECItem *param, void *wincx)
{
    return __PK11_CreateContextByRawKey(slot, type, origin, operation,
                                        key, param, wincx);
}

/*
 * Create a context from a key. We really should make sure we aren't using
 * the same key in multiple session!
 */
PK11Context *
PK11_CreateContextBySymKey(CK_MECHANISM_TYPE type, CK_ATTRIBUTE_TYPE operation,
                           PK11SymKey *symKey, SECItem *param)
{
    PK11SymKey *newKey;
    PK11Context *context;

    /* if this slot doesn't support the mechanism, go to a slot that does */
    newKey = pk11_ForceSlot(symKey, type, operation);
    if (newKey == NULL) {
        PK11_ReferenceSymKey(symKey);
    } else {
        symKey = newKey;
    }

    /* Context Adopts the symKey.... */
    context = pk11_CreateNewContextInSlot(type, symKey->slot, operation, symKey,
                                          param);
    PK11_FreeSymKey(symKey);
    return context;
}

/*
 * Digest contexts don't need keys, but the do need to find a slot.
 * Macing should use PK11_CreateContextBySymKey.
 */
PK11Context *
PK11_CreateDigestContext(SECOidTag hashAlg)
{
    /* digesting has to work without authentication to the slot */
    CK_MECHANISM_TYPE type;
    PK11SlotInfo *slot;
    PK11Context *context;
    SECItem param;

    type = PK11_AlgtagToMechanism(hashAlg);
    slot = PK11_GetBestSlot(type, NULL);
    if (slot == NULL) {
        PORT_SetError(SEC_ERROR_NO_MODULE);
        return NULL;
    }

    /* maybe should really be PK11_GenerateNewParam?? */
    param.data = NULL;
    param.len = 0;
    param.type = 0;

    context = pk11_CreateNewContextInSlot(type, slot, CKA_DIGEST, NULL, &param);
    PK11_FreeSlot(slot);
    return context;
}

/*
 * create a new context which is the clone of the state of old context.
 */
PK11Context *
PK11_CloneContext(PK11Context *old)
{
    PK11Context *newcx;
    PRBool needFree = PR_FALSE;
    SECStatus rv = SECSuccess;
    void *data;
    unsigned long len;

    newcx = pk11_CreateNewContextInSlot(old->type, old->slot, old->operation,
                                        old->key, old->param);
    if (newcx == NULL)
        return NULL;

    /* now clone the save state. First we need to find the save state
      * of the old session. If the old context owns it's session,
      * the state needs to be saved, otherwise the state is in saveData. */
    if (old->ownSession) {
        PK11_EnterContextMonitor(old);
        data = pk11_saveContext(old, NULL, &len);
        PK11_ExitContextMonitor(old);
        needFree = PR_TRUE;
    } else {
        data = old->savedData;
        len = old->savedLength;
    }

    if (data == NULL) {
        PK11_DestroyContext(newcx, PR_TRUE);
        return NULL;
    }

    /* now copy that state into our new context. Again we have different
      * work if the new context owns it's own session. If it does, we
      * restore the state gathered above. If it doesn't, we copy the
      * saveData pointer... */
    if (newcx->ownSession) {
        PK11_EnterContextMonitor(newcx);
        rv = pk11_restoreContext(newcx, data, len);
        PK11_ExitContextMonitor(newcx);
    } else {
        PORT_Assert(newcx->savedData != NULL);
        if ((newcx->savedData == NULL) || (newcx->savedLength < len)) {
            PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
            rv = SECFailure;
        } else {
            PORT_Memcpy(newcx->savedData, data, len);
            newcx->savedLength = len;
        }
    }

    if (needFree)
        PORT_Free(data);

    if (rv != SECSuccess) {
        PK11_DestroyContext(newcx, PR_TRUE);
        return NULL;
    }
    return newcx;
}

/*
 * save the current context state into a variable. Required to make FORTEZZA
 * work.
 */
SECStatus
PK11_SaveContext(PK11Context *cx, unsigned char *save, int *len, int saveLength)
{
    unsigned char *data = NULL;
    CK_ULONG length = saveLength;

    if (cx->ownSession) {
        PK11_EnterContextMonitor(cx);
        data = pk11_saveContextHelper(cx, save, &length);
        PK11_ExitContextMonitor(cx);
        if (data)
            *len = length;
    } else if ((unsigned)saveLength >= cx->savedLength) {
        data = (unsigned char *)cx->savedData;
        if (cx->savedData) {
            PORT_Memcpy(save, cx->savedData, cx->savedLength);
        }
        *len = cx->savedLength;
    }
    if (data != NULL) {
        if (cx->ownSession) {
            PORT_ZFree(data, length);
        }
        return SECSuccess;
    } else {
        return SECFailure;
    }
}

/* same as above, but may allocate the return buffer. */
unsigned char *
PK11_SaveContextAlloc(PK11Context *cx,
                      unsigned char *preAllocBuf, unsigned int pabLen,
                      unsigned int *stateLen)
{
    unsigned char *stateBuf = NULL;
    unsigned long length = (unsigned long)pabLen;

    if (cx->ownSession) {
        PK11_EnterContextMonitor(cx);
        stateBuf = pk11_saveContextHelper(cx, preAllocBuf, &length);
        PK11_ExitContextMonitor(cx);
        *stateLen = (stateBuf != NULL) ? length : 0;
    } else {
        if (pabLen < cx->savedLength) {
            stateBuf = (unsigned char *)PORT_Alloc(cx->savedLength);
            if (!stateBuf) {
                return (unsigned char *)NULL;
            }
        } else {
            stateBuf = preAllocBuf;
        }
        if (cx->savedData) {
            PORT_Memcpy(stateBuf, cx->savedData, cx->savedLength);
        }
        *stateLen = cx->savedLength;
    }
    return stateBuf;
}

/*
 * restore the context state into a new running context. Also required for
 * FORTEZZA .
 */
SECStatus
PK11_RestoreContext(PK11Context *cx, unsigned char *save, int len)
{
    SECStatus rv = SECSuccess;
    if (cx->ownSession) {
        PK11_EnterContextMonitor(cx);
        pk11_Finalize(cx);
        rv = pk11_restoreContext(cx, save, len);
        PK11_ExitContextMonitor(cx);
    } else {
        PORT_Assert(cx->savedData != NULL);
        if ((cx->savedData == NULL) || (cx->savedLength < (unsigned)len)) {
            PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
            rv = SECFailure;
        } else {
            PORT_Memcpy(cx->savedData, save, len);
            cx->savedLength = len;
        }
    }
    return rv;
}

/*
 * This is  to get FIPS compliance until we can convert
 * libjar to use PK11_ hashing functions. It returns PR_FALSE
 * if we can't get a PK11 Context.
 */
PRBool
PK11_HashOK(SECOidTag algID)
{
    PK11Context *cx;

    cx = PK11_CreateDigestContext(algID);
    if (cx == NULL)
        return PR_FALSE;
    PK11_DestroyContext(cx, PR_TRUE);
    return PR_TRUE;
}

/*
 * start a new digesting or Mac'ing operation on this context
 */
SECStatus
PK11_DigestBegin(PK11Context *cx)
{
    CK_MECHANISM mech_info;
    SECStatus rv;

    if (cx->init == PR_TRUE) {
        return SECSuccess;
    }

    /*
     * make sure the old context is clear first
     */
    PK11_EnterContextMonitor(cx);
    pk11_Finalize(cx);

    mech_info.mechanism = cx->type;
    mech_info.pParameter = cx->param->data;
    mech_info.ulParameterLen = cx->param->len;
    rv = pk11_context_init(cx, &mech_info);
    PK11_ExitContextMonitor(cx);

    if (rv != SECSuccess) {
        return SECFailure;
    }
    cx->init = PR_TRUE;
    return SECSuccess;
}

SECStatus
PK11_HashBuf(SECOidTag hashAlg, unsigned char *out, const unsigned char *in,
             PRInt32 len)
{
    PK11Context *context;
    unsigned int max_length;
    unsigned int out_length;
    SECStatus rv;

    /* len will be passed to PK11_DigestOp as unsigned. */
    if (len < 0) {
        PORT_SetError(SEC_ERROR_INVALID_ARGS);
        return SECFailure;
    }

    context = PK11_CreateDigestContext(hashAlg);
    if (context == NULL)
        return SECFailure;

    rv = PK11_DigestBegin(context);
    if (rv != SECSuccess) {
        PK11_DestroyContext(context, PR_TRUE);
        return rv;
    }

    rv = PK11_DigestOp(context, in, len);
    if (rv != SECSuccess) {
        PK11_DestroyContext(context, PR_TRUE);
        return rv;
    }

    /* XXX This really should have been an argument to this function! */
    max_length = HASH_ResultLenByOidTag(hashAlg);
    PORT_Assert(max_length);
    if (!max_length)
        max_length = HASH_LENGTH_MAX;

    rv = PK11_DigestFinal(context, out, &out_length, max_length);
    PK11_DestroyContext(context, PR_TRUE);
    return rv;
}

/*
 * execute a bulk encryption operation
 */
SECStatus
PK11_CipherOp(PK11Context *context, unsigned char *out, int *outlen,
              int maxout, const unsigned char *in, int inlen)
{
    CK_RV crv = CKR_OK;
    CK_ULONG length = maxout;
    CK_ULONG offset = 0;
    SECStatus rv = SECSuccess;
    unsigned char *saveOut = out;
    unsigned char *allocOut = NULL;

    /* if we ran out of session, we need to restore our previously stored
     * state.
     */
    PK11_EnterContextMonitor(context);
    if (!context->ownSession) {
        rv = pk11_restoreContext(context, context->savedData,
                                 context->savedLength);
        if (rv != SECSuccess) {
            PK11_ExitContextMonitor(context);
            return rv;
        }
    }

    /*
     * The fortezza hack is to send 8 extra bytes on the first encrypted and
     * lose them on the first decrypt.
     */
    if (context->fortezzaHack) {
        unsigned char random[8];
        if (context->operation == CKA_ENCRYPT) {
            PK11_ExitContextMonitor(context);
            rv = PK11_GenerateRandom(random, sizeof(random));
            PK11_EnterContextMonitor(context);

            /* since we are offseting the output, we can't encrypt back into
             * the same buffer... allocate a temporary buffer just for this
             * call. */
            allocOut = out = (unsigned char *)PORT_Alloc(maxout);
            if (out == NULL) {
                PK11_ExitContextMonitor(context);
                return SECFailure;
            }
            crv = PK11_GETTAB(context->slot)->C_EncryptUpdate(context->session, random, sizeof(random), out, &length);

            out += length;
            maxout -= length;
            offset = length;
        } else if (context->operation == CKA_DECRYPT) {
            length = sizeof(random);
            crv = PK11_GETTAB(context->slot)->C_DecryptUpdate(context->session, (CK_BYTE_PTR)in, sizeof(random), random, &length);
            inlen -= length;
            in += length;
            context->fortezzaHack = PR_FALSE;
        }
    }

    switch (context->operation) {
        case CKA_ENCRYPT:
            length = maxout;
            crv = PK11_GETTAB(context->slot)->C_EncryptUpdate(context->session, (CK_BYTE_PTR)in, inlen, out, &length);
            length += offset;
            break;
        case CKA_DECRYPT:
            length = maxout;
            crv = PK11_GETTAB(context->slot)->C_DecryptUpdate(context->session, (CK_BYTE_PTR)in, inlen, out, &length);
            break;
        default:
            crv = CKR_OPERATION_NOT_INITIALIZED;
            break;
    }

    if (crv != CKR_OK) {
        PORT_SetError(PK11_MapError(crv));
        *outlen = 0;
        rv = SECFailure;
    } else {
        *outlen = length;
    }

    if (context->fortezzaHack) {
        if (context->operation == CKA_ENCRYPT) {
            PORT_Assert(allocOut);
            PORT_Memcpy(saveOut, allocOut, length);
            PORT_Free(allocOut);
        }
        context->fortezzaHack = PR_FALSE;
    }

    /*
     * handle session starvation case.. use our last session to multiplex
     */
    if (!context->ownSession) {
        context->savedData = pk11_saveContext(context, context->savedData,
                                              &context->savedLength);
        if (context->savedData == NULL)
            rv = SECFailure;

        /* clear out out session for others to use */
        pk11_Finalize(context);
    }
    PK11_ExitContextMonitor(context);
    return rv;
}

/*
 * execute a digest/signature operation
 */
SECStatus
PK11_DigestOp(PK11Context *context, const unsigned char *in, unsigned inLen)
{
    CK_RV crv = CKR_OK;
    SECStatus rv = SECSuccess;

    if (inLen == 0) {
        return SECSuccess;
    }
    if (!in) {
        PORT_SetError(SEC_ERROR_INVALID_ARGS);
        return SECFailure;
    }

    /* if we ran out of session, we need to restore our previously stored
     * state.
     */
    context->init = PR_FALSE;
    PK11_EnterContextMonitor(context);
    if (!context->ownSession) {
        rv = pk11_restoreContext(context, context->savedData,
                                 context->savedLength);
        if (rv != SECSuccess) {
            PK11_ExitContextMonitor(context);
            return rv;
        }
    }

    switch (context->operation) {
        /* also for MAC'ing */
        case CKA_SIGN:
            crv = PK11_GETTAB(context->slot)->C_SignUpdate(context->session, (unsigned char *)in, inLen);
            break;
        case CKA_VERIFY:
            crv = PK11_GETTAB(context->slot)->C_VerifyUpdate(context->session, (unsigned char *)in, inLen);
            break;
        case CKA_DIGEST:
            crv = PK11_GETTAB(context->slot)->C_DigestUpdate(context->session, (unsigned char *)in, inLen);
            break;
        default:
            crv = CKR_OPERATION_NOT_INITIALIZED;
            break;
    }

    if (crv != CKR_OK) {
        PORT_SetError(PK11_MapError(crv));
        rv = SECFailure;
    }

    /*
     * handle session starvation case.. use our last session to multiplex
     */
    if (!context->ownSession) {
        context->savedData = pk11_saveContext(context, context->savedData,
                                              &context->savedLength);
        if (context->savedData == NULL)
            rv = SECFailure;

        /* clear out out session for others to use */
        pk11_Finalize(context);
    }
    PK11_ExitContextMonitor(context);
    return rv;
}

/*
 * Digest a key if possible./
 */
SECStatus
PK11_DigestKey(PK11Context *context, PK11SymKey *key)
{
    CK_RV crv = CKR_OK;
    SECStatus rv = SECSuccess;
    PK11SymKey *newKey = NULL;

    if (!context || !key) {
        PORT_SetError(SEC_ERROR_INVALID_ARGS);
        return SECFailure;
    }

    /* if we ran out of session, we need to restore our previously stored
     * state.
     */
    if (context->slot != key->slot) {
        newKey = pk11_CopyToSlot(context->slot, CKM_SSL3_SHA1_MAC, CKA_SIGN, key);
    } else {
        newKey = PK11_ReferenceSymKey(key);
    }

    context->init = PR_FALSE;
    PK11_EnterContextMonitor(context);
    if (!context->ownSession) {
        rv = pk11_restoreContext(context, context->savedData,
                                 context->savedLength);
        if (rv != SECSuccess) {
            PK11_ExitContextMonitor(context);
            PK11_FreeSymKey(newKey);
            return rv;
        }
    }

    if (newKey == NULL) {
        crv = CKR_KEY_TYPE_INCONSISTENT;
        if (key->data.data) {
            crv = PK11_GETTAB(context->slot)->C_DigestUpdate(context->session, key->data.data, key->data.len);
        }
    } else {
        crv = PK11_GETTAB(context->slot)->C_DigestKey(context->session, newKey->objectID);
    }

    if (crv != CKR_OK) {
        PORT_SetError(PK11_MapError(crv));
        rv = SECFailure;
    }

    /*
     * handle session starvation case.. use our last session to multiplex
     */
    if (!context->ownSession) {
        context->savedData = pk11_saveContext(context, context->savedData,
                                              &context->savedLength);
        if (context->savedData == NULL)
            rv = SECFailure;

        /* clear out out session for others to use */
        pk11_Finalize(context);
    }
    PK11_ExitContextMonitor(context);
    if (newKey)
        PK11_FreeSymKey(newKey);
    return rv;
}

/*
 * externally callable version of the lowercase pk11_finalize().
 */
SECStatus
PK11_Finalize(PK11Context *context)
{
    SECStatus rv;

    PK11_EnterContextMonitor(context);
    rv = pk11_Finalize(context);
    PK11_ExitContextMonitor(context);
    return rv;
}

/*
 * clean up a cipher operation, so the session can be used by
 * someone new.
 */
SECStatus
pk11_Finalize(PK11Context *context)
{
    CK_ULONG count = 0;
    CK_RV crv;
    unsigned char stackBuf[256];
    unsigned char *buffer = NULL;

    if (!context->ownSession) {
        return SECSuccess;
    }

finalize:
    switch (context->operation) {
        case CKA_ENCRYPT:
            crv = PK11_GETTAB(context->slot)->C_EncryptFinal(context->session, buffer, &count);
            break;
        case CKA_DECRYPT:
            crv = PK11_GETTAB(context->slot)->C_DecryptFinal(context->session, buffer, &count);
            break;
        case CKA_SIGN:
            crv = PK11_GETTAB(context->slot)->C_SignFinal(context->session, buffer, &count);
            break;
        case CKA_VERIFY:
            crv = PK11_GETTAB(context->slot)->C_VerifyFinal(context->session, buffer, count);
            break;
        case CKA_DIGEST:
            crv = PK11_GETTAB(context->slot)->C_DigestFinal(context->session, buffer, &count);
            break;
        default:
            crv = CKR_OPERATION_NOT_INITIALIZED;
            break;
    }

    if (crv != CKR_OK) {
        if (buffer != stackBuf) {
            PORT_Free(buffer);
        }
        if (crv == CKR_OPERATION_NOT_INITIALIZED) {
            /* if there's no operation, it is finalized */
            return SECSuccess;
        }
        PORT_SetError(PK11_MapError(crv));
        return SECFailure;
    }

    /* try to finalize the session with a buffer */
    if (buffer == NULL) {
        if (count <= sizeof stackBuf) {
            buffer = stackBuf;
        } else {
            buffer = PORT_Alloc(count);
            if (buffer == NULL) {
                PORT_SetError(SEC_ERROR_NO_MEMORY);
                return SECFailure;
            }
        }
        goto finalize;
    }
    if (buffer != stackBuf) {
        PORT_Free(buffer);
    }
    return SECSuccess;
}

/*
 *  Return the final digested or signed data...
 *  this routine can either take pre initialized data, or allocate data
 *  either out of an arena or out of the standard heap.
 */
SECStatus
PK11_DigestFinal(PK11Context *context, unsigned char *data,
                 unsigned int *outLen, unsigned int length)
{
    CK_ULONG len;
    CK_RV crv;
    SECStatus rv;

    /* if we ran out of session, we need to restore our previously stored
     * state.
     */
    PK11_EnterContextMonitor(context);
    if (!context->ownSession) {
        rv = pk11_restoreContext(context, context->savedData,
                                 context->savedLength);
        if (rv != SECSuccess) {
            PK11_ExitContextMonitor(context);
            return rv;
        }
    }

    len = length;
    switch (context->operation) {
        case CKA_SIGN:
            crv = PK11_GETTAB(context->slot)->C_SignFinal(context->session, data, &len);
            break;
        case CKA_VERIFY:
            crv = PK11_GETTAB(context->slot)->C_VerifyFinal(context->session, data, len);
            break;
        case CKA_DIGEST:
            crv = PK11_GETTAB(context->slot)->C_DigestFinal(context->session, data, &len);
            break;
        case CKA_ENCRYPT:
            crv = PK11_GETTAB(context->slot)->C_EncryptFinal(context->session, data, &len);
            break;
        case CKA_DECRYPT:
            crv = PK11_GETTAB(context->slot)->C_DecryptFinal(context->session, data, &len);
            break;
        default:
            crv = CKR_OPERATION_NOT_INITIALIZED;
            break;
    }
    PK11_ExitContextMonitor(context);

    *outLen = (unsigned int)len;
    context->init = PR_FALSE; /* allow Begin to start up again */

    if (crv != CKR_OK) {
        PORT_SetError(PK11_MapError(crv));
        return SECFailure;
    }
    return SECSuccess;
}