summaryrefslogtreecommitdiff
path: root/nss/lib/pkcs7/p7encode.c
blob: af3da59187f422058b1426b3d62e7296204cfdb3 (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
/* 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/. */

/*
 * PKCS7 encoding.
 */

#include "p7local.h"

#include "cert.h"
#include "cryptohi.h"
#include "keyhi.h"
#include "secasn1.h"
#include "secoid.h"
#include "secitem.h"
#include "pk11func.h"
#include "secerr.h"
#include "sechash.h" /* for HASH_GetHashObject() */

struct sec_pkcs7_encoder_output {
    SEC_PKCS7EncoderOutputCallback outputfn;
    void *outputarg;
};

struct SEC_PKCS7EncoderContextStr {
    SEC_ASN1EncoderContext *ecx;
    SEC_PKCS7ContentInfo *cinfo;
    struct sec_pkcs7_encoder_output output;
    sec_PKCS7CipherObject *encryptobj;
    const SECHashObject *digestobj;
    void *digestcx;
};

/*
 * The little output function that the ASN.1 encoder calls to hand
 * us bytes which we in turn hand back to our caller (via the callback
 * they gave us).
 */
static void
sec_pkcs7_encoder_out(void *arg, const char *buf, unsigned long len,
                      int depth, SEC_ASN1EncodingPart data_kind)
{
    struct sec_pkcs7_encoder_output *output;

    output = (struct sec_pkcs7_encoder_output *)arg;
    output->outputfn(output->outputarg, buf, len);
}

static sec_PKCS7CipherObject *
sec_pkcs7_encoder_start_encrypt(SEC_PKCS7ContentInfo *cinfo,
                                PK11SymKey *orig_bulkkey)
{
    SECOidTag kind;
    sec_PKCS7CipherObject *encryptobj;
    SEC_PKCS7RecipientInfo **recipientinfos, *ri;
    SEC_PKCS7EncryptedContentInfo *enccinfo;
    SECKEYPublicKey *publickey = NULL;
    SECKEYPrivateKey *ourPrivKey = NULL;
    PK11SymKey *bulkkey;
    void *mark;
    int i;
    PLArenaPool *arena = NULL;

    kind = SEC_PKCS7ContentType(cinfo);
    switch (kind) {
        default:
        case SEC_OID_PKCS7_DATA:
        case SEC_OID_PKCS7_DIGESTED_DATA:
        case SEC_OID_PKCS7_SIGNED_DATA:
            recipientinfos = NULL;
            enccinfo = NULL;
            break;
        case SEC_OID_PKCS7_ENCRYPTED_DATA: {
            SEC_PKCS7EncryptedData *encdp;

            /* To do EncryptedData we *must* be given a bulk key. */
            PORT_Assert(orig_bulkkey != NULL);
            if (orig_bulkkey == NULL) {
                /* XXX error? */
                return NULL;
            }

            encdp = cinfo->content.encryptedData;
            recipientinfos = NULL;
            enccinfo = &(encdp->encContentInfo);
        } break;
        case SEC_OID_PKCS7_ENVELOPED_DATA: {
            SEC_PKCS7EnvelopedData *envdp;

            envdp = cinfo->content.envelopedData;
            recipientinfos = envdp->recipientInfos;
            enccinfo = &(envdp->encContentInfo);
        } break;
        case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA: {
            SEC_PKCS7SignedAndEnvelopedData *saedp;

            saedp = cinfo->content.signedAndEnvelopedData;
            recipientinfos = saedp->recipientInfos;
            enccinfo = &(saedp->encContentInfo);
        } break;
    }

    if (enccinfo == NULL)
        return NULL;

    bulkkey = orig_bulkkey;
    if (bulkkey == NULL) {
        CK_MECHANISM_TYPE type = PK11_AlgtagToMechanism(enccinfo->encalg);
        PK11SlotInfo *slot;

        slot = PK11_GetBestSlot(type, cinfo->pwfn_arg);
        if (slot == NULL) {
            return NULL;
        }
        bulkkey = PK11_KeyGen(slot, type, NULL, enccinfo->keysize / 8,
                              cinfo->pwfn_arg);
        PK11_FreeSlot(slot);
        if (bulkkey == NULL) {
            return NULL;
        }
    }

    encryptobj = NULL;
    mark = PORT_ArenaMark(cinfo->poolp);

    /*
     * Encrypt the bulk key with the public key of each recipient.
     */
    for (i = 0; recipientinfos && (ri = recipientinfos[i]) != NULL; i++) {
        CERTCertificate *cert;
        SECOidTag certalgtag, encalgtag;
        SECStatus rv;
        int data_len;
        SECItem *params = NULL;

        cert = ri->cert;
        PORT_Assert(cert != NULL);
        if (cert == NULL)
            continue;

        /*
         * XXX Want an interface that takes a cert and some data and
         * fills in an algorithmID and encrypts the data with the public
         * key from the cert.  Or, give me two interfaces -- one which
         * gets the algorithm tag from a cert (I should not have to go
         * down into the subjectPublicKeyInfo myself) and another which
         * takes a public key and algorithm tag and data and encrypts
         * the data.  Or something like that.  The point is that all
         * of the following hardwired RSA stuff should be done elsewhere.
         */

        certalgtag = SECOID_GetAlgorithmTag(&(cert->subjectPublicKeyInfo.algorithm));

        switch (certalgtag) {
            case SEC_OID_PKCS1_RSA_ENCRYPTION:
                encalgtag = certalgtag;
                publickey = CERT_ExtractPublicKey(cert);
                if (publickey == NULL)
                    goto loser;

                data_len = SECKEY_PublicKeyStrength(publickey);
                ri->encKey.data =
                    (unsigned char *)PORT_ArenaAlloc(cinfo->poolp, data_len);
                ri->encKey.len = data_len;
                if (ri->encKey.data == NULL)
                    goto loser;

                rv = PK11_PubWrapSymKey(PK11_AlgtagToMechanism(certalgtag), publickey,
                                        bulkkey, &ri->encKey);

                SECKEY_DestroyPublicKey(publickey);
                publickey = NULL;
                if (rv != SECSuccess)
                    goto loser;
                params = NULL; /* paranoia */
                break;
            default:
                PORT_SetError(SEC_ERROR_INVALID_ALGORITHM);
                goto loser;
        }

        rv = SECOID_SetAlgorithmID(cinfo->poolp, &ri->keyEncAlg, encalgtag,
                                   params);
        if (rv != SECSuccess)
            goto loser;
        if (arena)
            PORT_FreeArena(arena, PR_FALSE);
        arena = NULL;
    }

    encryptobj = sec_PKCS7CreateEncryptObject(cinfo->poolp, bulkkey,
                                              enccinfo->encalg,
                                              &(enccinfo->contentEncAlg));
    if (encryptobj != NULL) {
        PORT_ArenaUnmark(cinfo->poolp, mark);
        mark = NULL; /* good one; do not want to release */
    }
/* fallthru */

loser:
    if (arena) {
        PORT_FreeArena(arena, PR_FALSE);
    }
    if (publickey) {
        SECKEY_DestroyPublicKey(publickey);
    }
    if (ourPrivKey) {
        SECKEY_DestroyPrivateKey(ourPrivKey);
    }
    if (mark != NULL) {
        PORT_ArenaRelease(cinfo->poolp, mark);
    }
    if (orig_bulkkey == NULL) {
        if (bulkkey)
            PK11_FreeSymKey(bulkkey);
    }

    return encryptobj;
}

static void
sec_pkcs7_encoder_notify(void *arg, PRBool before, void *dest, int depth)
{
    SEC_PKCS7EncoderContext *p7ecx;
    SEC_PKCS7ContentInfo *cinfo;
    SECOidTag kind;
    PRBool before_content;

    /*
     * We want to notice just before the content field.  After fields are
     * not interesting to us.
     */
    if (!before)
        return;

    p7ecx = (SEC_PKCS7EncoderContext *)arg;
    cinfo = p7ecx->cinfo;

    before_content = PR_FALSE;

    /*
     * Watch for the content field, at which point we want to instruct
     * the ASN.1 encoder to start taking bytes from the buffer.
     *
     * XXX The following assumes the inner content type is data;
     * if/when we want to handle fully nested types, this will have
     * to recurse until reaching the innermost data content.
     */
    kind = SEC_PKCS7ContentType(cinfo);
    switch (kind) {
        default:
        case SEC_OID_PKCS7_DATA:
            if (dest == &(cinfo->content.data))
                before_content = PR_TRUE;
            break;

        case SEC_OID_PKCS7_DIGESTED_DATA: {
            SEC_PKCS7DigestedData *digd;

            digd = cinfo->content.digestedData;
            if (digd == NULL)
                break;

            if (dest == &(digd->contentInfo.content))
                before_content = PR_TRUE;
        } break;

        case SEC_OID_PKCS7_ENCRYPTED_DATA: {
            SEC_PKCS7EncryptedData *encd;

            encd = cinfo->content.encryptedData;
            if (encd == NULL)
                break;

            if (dest == &(encd->encContentInfo.encContent))
                before_content = PR_TRUE;
        } break;

        case SEC_OID_PKCS7_ENVELOPED_DATA: {
            SEC_PKCS7EnvelopedData *envd;

            envd = cinfo->content.envelopedData;
            if (envd == NULL)
                break;

            if (dest == &(envd->encContentInfo.encContent))
                before_content = PR_TRUE;
        } break;

        case SEC_OID_PKCS7_SIGNED_DATA: {
            SEC_PKCS7SignedData *sigd;

            sigd = cinfo->content.signedData;
            if (sigd == NULL)
                break;

            if (dest == &(sigd->contentInfo.content))
                before_content = PR_TRUE;
        } break;

        case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA: {
            SEC_PKCS7SignedAndEnvelopedData *saed;

            saed = cinfo->content.signedAndEnvelopedData;
            if (saed == NULL)
                break;

            if (dest == &(saed->encContentInfo.encContent))
                before_content = PR_TRUE;
        } break;
    }

    if (before_content) {
        /*
         * This will cause the next SEC_ASN1EncoderUpdate to take the
         * contents bytes from the passed-in buffer.
         */
        SEC_ASN1EncoderSetTakeFromBuf(p7ecx->ecx);
        /*
         * And that is all we needed this notify function for.
         */
        SEC_ASN1EncoderClearNotifyProc(p7ecx->ecx);
    }
}

static SEC_PKCS7EncoderContext *
sec_pkcs7_encoder_start_contexts(SEC_PKCS7ContentInfo *cinfo,
                                 PK11SymKey *bulkkey)
{
    SEC_PKCS7EncoderContext *p7ecx;
    SECOidTag kind;
    PRBool encrypt;
    SECItem **digests;
    SECAlgorithmID *digestalg, **digestalgs;

    p7ecx =
        (SEC_PKCS7EncoderContext *)PORT_ZAlloc(sizeof(SEC_PKCS7EncoderContext));
    if (p7ecx == NULL)
        return NULL;

    digests = NULL;
    digestalg = NULL;
    digestalgs = NULL;
    encrypt = PR_FALSE;

    kind = SEC_PKCS7ContentType(cinfo);
    switch (kind) {
        default:
        case SEC_OID_PKCS7_DATA:
            break;
        case SEC_OID_PKCS7_DIGESTED_DATA:
            digestalg = &(cinfo->content.digestedData->digestAlg);
            break;
        case SEC_OID_PKCS7_SIGNED_DATA:
            digests = cinfo->content.signedData->digests;
            digestalgs = cinfo->content.signedData->digestAlgorithms;
            break;
        case SEC_OID_PKCS7_ENCRYPTED_DATA:
        case SEC_OID_PKCS7_ENVELOPED_DATA:
            encrypt = PR_TRUE;
            break;
        case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
            digests = cinfo->content.signedAndEnvelopedData->digests;
            digestalgs = cinfo->content.signedAndEnvelopedData->digestAlgorithms;
            encrypt = PR_TRUE;
            break;
    }

    if (encrypt) {
        p7ecx->encryptobj = sec_pkcs7_encoder_start_encrypt(cinfo, bulkkey);
        if (p7ecx->encryptobj == NULL) {
            PORT_Free(p7ecx);
            return NULL;
        }
    }

    if (digestalgs != NULL) {
        if (digests != NULL) {
            /* digests already created (probably for detached data) */
            digestalg = NULL;
        } else {
            /*
             * XXX Some day we should handle multiple digests; for now,
             * assume only one will be done.
             */
            PORT_Assert(digestalgs[0] != NULL && digestalgs[1] == NULL);
            digestalg = digestalgs[0];
        }
    }

    if (digestalg != NULL) {
        SECOidTag oidTag = SECOID_FindOIDTag(&(digestalg->algorithm));

        p7ecx->digestobj = HASH_GetHashObjectByOidTag(oidTag);
        if (p7ecx->digestobj != NULL) {
            p7ecx->digestcx = (*p7ecx->digestobj->create)();
            if (p7ecx->digestcx == NULL)
                p7ecx->digestobj = NULL;
            else
                (*p7ecx->digestobj->begin)(p7ecx->digestcx);
        }
        if (p7ecx->digestobj == NULL) {
            if (p7ecx->encryptobj != NULL)
                sec_PKCS7DestroyEncryptObject(p7ecx->encryptobj);
            PORT_Free(p7ecx);
            return NULL;
        }
    }

    p7ecx->cinfo = cinfo;
    return p7ecx;
}

SEC_PKCS7EncoderContext *
SEC_PKCS7EncoderStart(SEC_PKCS7ContentInfo *cinfo,
                      SEC_PKCS7EncoderOutputCallback outputfn,
                      void *outputarg,
                      PK11SymKey *bulkkey)
{
    SEC_PKCS7EncoderContext *p7ecx;
    SECStatus rv;

    p7ecx = sec_pkcs7_encoder_start_contexts(cinfo, bulkkey);
    if (p7ecx == NULL)
        return NULL;

    p7ecx->output.outputfn = outputfn;
    p7ecx->output.outputarg = outputarg;

    /*
     * Initialize the BER encoder.
     */
    p7ecx->ecx = SEC_ASN1EncoderStart(cinfo, sec_PKCS7ContentInfoTemplate,
                                      sec_pkcs7_encoder_out, &(p7ecx->output));
    if (p7ecx->ecx == NULL) {
        PORT_Free(p7ecx);
        return NULL;
    }

    /*
     * Indicate that we are streaming.  We will be streaming until we
     * get past the contents bytes.
     */
    SEC_ASN1EncoderSetStreaming(p7ecx->ecx);

    /*
     * The notify function will watch for the contents field.
     */
    SEC_ASN1EncoderSetNotifyProc(p7ecx->ecx, sec_pkcs7_encoder_notify, p7ecx);

    /*
     * This will encode everything up to the content bytes.  (The notify
     * function will then cause the encoding to stop there.)  Then our
     * caller can start passing contents bytes to our Update, which we
     * will pass along.
     */
    rv = SEC_ASN1EncoderUpdate(p7ecx->ecx, NULL, 0);
    if (rv != SECSuccess) {
        PORT_Free(p7ecx);
        return NULL;
    }

    return p7ecx;
}

/*
 * XXX If/when we support nested contents, this needs to be revised.
 */
static SECStatus
sec_pkcs7_encoder_work_data(SEC_PKCS7EncoderContext *p7ecx, SECItem *dest,
                            const unsigned char *data, unsigned long len,
                            PRBool final)
{
    unsigned char *buf = NULL;
    SECStatus rv;

    rv = SECSuccess; /* may as well be optimistic */

    /*
     * We should really have data to process, or we should be trying
     * to finish/flush the last block.  (This is an overly paranoid
     * check since all callers are in this file and simple inspection
     * proves they do it right.  But it could find a bug in future
     * modifications/development, that is why it is here.)
     */
    PORT_Assert((data != NULL && len) || final);

    /*
     * Update the running digest.
     * XXX This needs modification if/when we handle multiple digests.
     */
    if (len && p7ecx->digestobj != NULL) {
        (*p7ecx->digestobj->update)(p7ecx->digestcx, data, len);
    }

    /*
     * Encrypt this chunk.
     */
    if (p7ecx->encryptobj != NULL) {
        /* XXX the following lengths should all be longs? */
        unsigned int inlen;  /* length of data being encrypted */
        unsigned int outlen; /* length of encrypted data */
        unsigned int buflen; /* length available for encrypted data */

        inlen = len;
        buflen = sec_PKCS7EncryptLength(p7ecx->encryptobj, inlen, final);
        if (buflen == 0) {
            /*
             * No output is expected, but the input data may be buffered
             * so we still have to call Encrypt.
             */
            rv = sec_PKCS7Encrypt(p7ecx->encryptobj, NULL, &outlen, 0,
                                  data, inlen, final);
            if (final) {
                len = 0;
                goto done;
            }
            return rv;
        }

        if (dest != NULL)
            buf = (unsigned char *)PORT_ArenaAlloc(p7ecx->cinfo->poolp, buflen);
        else
            buf = (unsigned char *)PORT_Alloc(buflen);

        if (buf == NULL) {
            rv = SECFailure;
        } else {
            rv = sec_PKCS7Encrypt(p7ecx->encryptobj, buf, &outlen, buflen,
                                  data, inlen, final);
            data = buf;
            len = outlen;
        }
        if (rv != SECSuccess) {
            if (final)
                goto done;
            return rv;
        }
    }

    if (p7ecx->ecx != NULL) {
        /*
         * Encode the contents bytes.
         */
        if (len) {
            rv = SEC_ASN1EncoderUpdate(p7ecx->ecx, (const char *)data, len);
        }
    }

done:
    if (p7ecx->encryptobj != NULL) {
        if (final)
            sec_PKCS7DestroyEncryptObject(p7ecx->encryptobj);
        if (dest != NULL) {
            dest->data = buf;
            dest->len = len;
        } else if (buf != NULL) {
            PORT_Free(buf);
        }
    }

    if (final && p7ecx->digestobj != NULL) {
        SECItem *digest, **digests, ***digestsp;
        unsigned char *digdata;
        SECOidTag kind;

        kind = SEC_PKCS7ContentType(p7ecx->cinfo);
        switch (kind) {
            default:
                PORT_Assert(0);
                return SECFailure;
            case SEC_OID_PKCS7_DIGESTED_DATA:
                digest = &(p7ecx->cinfo->content.digestedData->digest);
                digestsp = NULL;
                break;
            case SEC_OID_PKCS7_SIGNED_DATA:
                digest = NULL;
                digestsp = &(p7ecx->cinfo->content.signedData->digests);
                break;
            case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
                digest = NULL;
                digestsp = &(p7ecx->cinfo->content.signedAndEnvelopedData->digests);
                break;
        }

        digdata = (unsigned char *)PORT_ArenaAlloc(p7ecx->cinfo->poolp,
                                                   p7ecx->digestobj->length);
        if (digdata == NULL)
            return SECFailure;

        if (digestsp != NULL) {
            PORT_Assert(digest == NULL);

            digest = (SECItem *)PORT_ArenaAlloc(p7ecx->cinfo->poolp,
                                                sizeof(SECItem));
            digests = (SECItem **)PORT_ArenaAlloc(p7ecx->cinfo->poolp,
                                                  2 * sizeof(SECItem *));
            if (digests == NULL || digest == NULL)
                return SECFailure;

            digests[0] = digest;
            digests[1] = NULL;

            *digestsp = digests;
        }

        PORT_Assert(digest != NULL);

        digest->data = digdata;
        digest->len = p7ecx->digestobj->length;

        (*p7ecx->digestobj->end)(p7ecx->digestcx, digest->data,
                                 &(digest->len), digest->len);
        (*p7ecx->digestobj->destroy)(p7ecx->digestcx, PR_TRUE);
    }

    return rv;
}

SECStatus
SEC_PKCS7EncoderUpdate(SEC_PKCS7EncoderContext *p7ecx,
                       const char *data, unsigned long len)
{
    /* XXX Error handling needs help.  Return what?  Do "Finish" on failure? */
    return sec_pkcs7_encoder_work_data(p7ecx, NULL,
                                       (const unsigned char *)data, len,
                                       PR_FALSE);
}

static SECStatus
sec_pkcs7_encoder_sig_and_certs(SEC_PKCS7ContentInfo *cinfo,
                                SECKEYGetPasswordKey pwfn, void *pwfnarg)
{
    SECOidTag kind;
    CERTCertificate **certs;
    CERTCertificateList **certlists;
    SECAlgorithmID **digestalgs;
    SECItem **digests;
    SEC_PKCS7SignerInfo *signerinfo, **signerinfos;
    SECItem **rawcerts, ***rawcertsp;
    PLArenaPool *poolp;
    int certcount;
    int ci, cli, rci, si;

    kind = SEC_PKCS7ContentType(cinfo);
    switch (kind) {
        default:
        case SEC_OID_PKCS7_DATA:
        case SEC_OID_PKCS7_DIGESTED_DATA:
        case SEC_OID_PKCS7_ENCRYPTED_DATA:
        case SEC_OID_PKCS7_ENVELOPED_DATA:
            certs = NULL;
            certlists = NULL;
            digestalgs = NULL;
            digests = NULL;
            signerinfos = NULL;
            rawcertsp = NULL;
            break;
        case SEC_OID_PKCS7_SIGNED_DATA: {
            SEC_PKCS7SignedData *sdp;

            sdp = cinfo->content.signedData;
            certs = sdp->certs;
            certlists = sdp->certLists;
            digestalgs = sdp->digestAlgorithms;
            digests = sdp->digests;
            signerinfos = sdp->signerInfos;
            rawcertsp = &(sdp->rawCerts);
        } break;
        case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA: {
            SEC_PKCS7SignedAndEnvelopedData *saedp;

            saedp = cinfo->content.signedAndEnvelopedData;
            certs = saedp->certs;
            certlists = saedp->certLists;
            digestalgs = saedp->digestAlgorithms;
            digests = saedp->digests;
            signerinfos = saedp->signerInfos;
            rawcertsp = &(saedp->rawCerts);
        } break;
    }

    if (certs == NULL && certlists == NULL && signerinfos == NULL)
        return SECSuccess; /* nothing for us to do! */

    poolp = cinfo->poolp;
    certcount = 0;

    if (signerinfos != NULL) {
        SECOidTag digestalgtag;
        int di;
        SECStatus rv;
        CERTCertificate *cert;
        SECKEYPrivateKey *privkey;
        SECItem signature;
        SECOidTag signalgtag;

        PORT_Assert(digestalgs != NULL && digests != NULL);

        /*
         * If one fails, we bail right then.  If we want to continue and
         * try to do subsequent signatures, this loop, and the departures
         * from it, will need to be reworked.
         */
        for (si = 0; signerinfos[si] != NULL; si++) {

            signerinfo = signerinfos[si];

            /* find right digest */
            digestalgtag = SECOID_GetAlgorithmTag(&(signerinfo->digestAlg));
            for (di = 0; digestalgs[di] != NULL; di++) {
                /* XXX Should I be comparing more than the tag? */
                if (digestalgtag == SECOID_GetAlgorithmTag(digestalgs[di]))
                    break;
            }
            if (digestalgs[di] == NULL) {
                /* XXX oops; do what? set an error? */
                return SECFailure;
            }
            PORT_Assert(digests[di] != NULL);

            cert = signerinfo->cert;
            privkey = PK11_FindKeyByAnyCert(cert, pwfnarg);
            if (privkey == NULL)
                return SECFailure;

            /*
             * XXX I think there should be a cert-level interface for this,
             * so that I do not have to know about subjectPublicKeyInfo...
             */
            signalgtag = SECOID_GetAlgorithmTag(&(cert->subjectPublicKeyInfo.algorithm));

            if (signerinfo->authAttr != NULL) {
                SEC_PKCS7Attribute *attr;
                SECItem encoded_attrs;
                SECItem *dummy;
                SECOidTag algid;

                /*
                 * First, find and fill in the message digest attribute.
                 */
                attr = sec_PKCS7FindAttribute(signerinfo->authAttr,
                                              SEC_OID_PKCS9_MESSAGE_DIGEST,
                                              PR_TRUE);
                PORT_Assert(attr != NULL);
                if (attr == NULL) {
                    SECKEY_DestroyPrivateKey(privkey);
                    return SECFailure;
                }

                /*
                 * XXX The second half of the following assertion prevents
                 * the encoder from being called twice on the same content.
                 * Either just remove the second half the assertion, or
                 * change the code to check if the value already there is
                 * the same as digests[di], whichever seems more right.
                 */
                PORT_Assert(attr->values != NULL && attr->values[0] == NULL);
                attr->values[0] = digests[di];

                /*
                 * Before encoding, reorder the attributes so that when they
                 * are encoded, they will be conforming DER, which is required
                 * to have a specific order and that is what must be used for
                 * the hash/signature.  We do this here, rather than building
                 * it into EncodeAttributes, because we do not want to do
                 * such reordering on incoming messages (which also uses
                 * EncodeAttributes) or our old signatures (and other "broken"
                 * implementations) will not verify.  So, we want to guarantee
                 * that we send out good DER encodings of attributes, but not
                 * to expect to receive them.
                 */
                rv = sec_PKCS7ReorderAttributes(signerinfo->authAttr);
                if (rv != SECSuccess) {
                    SECKEY_DestroyPrivateKey(privkey);
                    return SECFailure;
                }

                encoded_attrs.data = NULL;
                encoded_attrs.len = 0;
                dummy = sec_PKCS7EncodeAttributes(NULL, &encoded_attrs,
                                                  &(signerinfo->authAttr));
                if (dummy == NULL) {
                    SECKEY_DestroyPrivateKey(privkey);
                    return SECFailure;
                }

                algid = SEC_GetSignatureAlgorithmOidTag(privkey->keyType,
                                                        digestalgtag);
                if (algid == SEC_OID_UNKNOWN) {
                    PORT_SetError(SEC_ERROR_INVALID_ALGORITHM);
                    SECKEY_DestroyPrivateKey(privkey);
                    return SECFailure;
                }
                rv = SEC_SignData(&signature,
                                  encoded_attrs.data, encoded_attrs.len,
                                  privkey,
                                  algid);
                SECITEM_FreeItem(&encoded_attrs, PR_FALSE);
            } else {
                rv = SGN_Digest(privkey, digestalgtag, &signature,
                                digests[di]);
            }

            SECKEY_DestroyPrivateKey(privkey);

            if (rv != SECSuccess)
                return rv;

            rv = SECITEM_CopyItem(poolp, &(signerinfo->encDigest), &signature);
            if (rv != SECSuccess)
                return rv;

            SECITEM_FreeItem(&signature, PR_FALSE);

            rv = SECOID_SetAlgorithmID(poolp, &(signerinfo->digestEncAlg),
                                       signalgtag, NULL);
            if (rv != SECSuccess)
                return SECFailure;

            /*
             * Count the cert chain for this signer.
             */
            if (signerinfo->certList != NULL)
                certcount += signerinfo->certList->len;
        }
    }

    if (certs != NULL) {
        for (ci = 0; certs[ci] != NULL; ci++)
            certcount++;
    }

    if (certlists != NULL) {
        for (cli = 0; certlists[cli] != NULL; cli++)
            certcount += certlists[cli]->len;
    }

    if (certcount == 0)
        return SECSuccess; /* signing done; no certs */

    /*
     * Combine all of the certs and cert chains into rawcerts.
     * Note: certcount is an upper bound; we may not need that many slots
     * but we will allocate anyway to avoid having to do another pass.
     * (The temporary space saving is not worth it.)
     */
    rawcerts = (SECItem **)PORT_ArenaAlloc(poolp,
                                           (certcount + 1) * sizeof(SECItem *));
    if (rawcerts == NULL)
        return SECFailure;

    /*
     * XXX Want to check for duplicates and not add *any* cert that is
     * already in the set.  This will be more important when we start
     * dealing with larger sets of certs, dual-key certs (signing and
     * encryption), etc.  For the time being we can slide by...
     */
    rci = 0;
    if (signerinfos != NULL) {
        for (si = 0; signerinfos[si] != NULL; si++) {
            signerinfo = signerinfos[si];
            for (ci = 0; ci < signerinfo->certList->len; ci++)
                rawcerts[rci++] = &(signerinfo->certList->certs[ci]);
        }
    }

    if (certs != NULL) {
        for (ci = 0; certs[ci] != NULL; ci++)
            rawcerts[rci++] = &(certs[ci]->derCert);
    }

    if (certlists != NULL) {
        for (cli = 0; certlists[cli] != NULL; cli++) {
            for (ci = 0; ci < certlists[cli]->len; ci++)
                rawcerts[rci++] = &(certlists[cli]->certs[ci]);
        }
    }

    rawcerts[rci] = NULL;
    *rawcertsp = rawcerts;

    return SECSuccess;
}

SECStatus
SEC_PKCS7EncoderFinish(SEC_PKCS7EncoderContext *p7ecx,
                       SECKEYGetPasswordKey pwfn, void *pwfnarg)
{
    SECStatus rv;

    /*
     * Flush out any remaining data.
     */
    rv = sec_pkcs7_encoder_work_data(p7ecx, NULL, NULL, 0, PR_TRUE);

    /*
     * Turn off streaming stuff.
     */
    SEC_ASN1EncoderClearTakeFromBuf(p7ecx->ecx);
    SEC_ASN1EncoderClearStreaming(p7ecx->ecx);

    if (rv != SECSuccess)
        goto loser;

    rv = sec_pkcs7_encoder_sig_and_certs(p7ecx->cinfo, pwfn, pwfnarg);
    if (rv != SECSuccess)
        goto loser;

    rv = SEC_ASN1EncoderUpdate(p7ecx->ecx, NULL, 0);

loser:
    SEC_ASN1EncoderFinish(p7ecx->ecx);
    PORT_Free(p7ecx);
    return rv;
}

/*
 * Abort the ASN.1 stream. Used by pkcs 12
 */
void
SEC_PKCS7EncoderAbort(SEC_PKCS7EncoderContext *p7ecx, int error)
{
    PORT_Assert(p7ecx);
    SEC_ASN1EncoderAbort(p7ecx->ecx, error);
}

/*
 * After this routine is called, the entire PKCS7 contentInfo is ready
 * to be encoded.  This is used internally, but can also be called from
 * elsewhere for those who want to be able to just have pointers to
 * the ASN1 template for pkcs7 contentInfo built into their own encodings.
 */
SECStatus
SEC_PKCS7PrepareForEncode(SEC_PKCS7ContentInfo *cinfo,
                          PK11SymKey *bulkkey,
                          SECKEYGetPasswordKey pwfn,
                          void *pwfnarg)
{
    SEC_PKCS7EncoderContext *p7ecx;
    SECItem *content, *enc_content;
    SECStatus rv;

    p7ecx = sec_pkcs7_encoder_start_contexts(cinfo, bulkkey);
    if (p7ecx == NULL)
        return SECFailure;

    content = SEC_PKCS7GetContent(cinfo);

    if (p7ecx->encryptobj != NULL) {
        SECOidTag kind;
        SEC_PKCS7EncryptedContentInfo *enccinfo;

        kind = SEC_PKCS7ContentType(p7ecx->cinfo);
        switch (kind) {
            default:
                PORT_Assert(0);
                rv = SECFailure;
                goto loser;
            case SEC_OID_PKCS7_ENCRYPTED_DATA:
                enccinfo = &(p7ecx->cinfo->content.encryptedData->encContentInfo);
                break;
            case SEC_OID_PKCS7_ENVELOPED_DATA:
                enccinfo = &(p7ecx->cinfo->content.envelopedData->encContentInfo);
                break;
            case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
                enccinfo = &(p7ecx->cinfo->content.signedAndEnvelopedData->encContentInfo);
                break;
        }
        enc_content = &(enccinfo->encContent);
    } else {
        enc_content = NULL;
    }

    if (content != NULL && content->data != NULL && content->len) {
        rv = sec_pkcs7_encoder_work_data(p7ecx, enc_content,
                                         content->data, content->len, PR_TRUE);
        if (rv != SECSuccess)
            goto loser;
    }

    rv = sec_pkcs7_encoder_sig_and_certs(cinfo, pwfn, pwfnarg);

loser:
    PORT_Free(p7ecx);
    return rv;
}

/*
 * Encode a PKCS7 object, in one shot.  All necessary components
 * of the object must already be specified.  Either the data has
 * already been included (via SetContent), or the data is detached,
 * or there is no data at all (certs-only).
 *
 * "cinfo" specifies the object to be encoded.
 *
 * "outputfn" is where the encoded bytes will be passed.
 *
 * "outputarg" is an opaque argument to the above callback.
 *
 * "bulkkey" specifies the bulk encryption key to use.   This argument
 * can be NULL if no encryption is being done, or if the bulk key should
 * be generated internally (usually the case for EnvelopedData but never
 * for EncryptedData, which *must* provide a bulk encryption key).
 *
 * "pwfn" is a callback for getting the password which protects the
 * private key of the signer.  This argument can be NULL if it is known
 * that no signing is going to be done.
 *
 * "pwfnarg" is an opaque argument to the above callback.
 */
SECStatus
SEC_PKCS7Encode(SEC_PKCS7ContentInfo *cinfo,
                SEC_PKCS7EncoderOutputCallback outputfn,
                void *outputarg,
                PK11SymKey *bulkkey,
                SECKEYGetPasswordKey pwfn,
                void *pwfnarg)
{
    SECStatus rv;

    rv = SEC_PKCS7PrepareForEncode(cinfo, bulkkey, pwfn, pwfnarg);
    if (rv == SECSuccess) {
        struct sec_pkcs7_encoder_output outputcx;

        outputcx.outputfn = outputfn;
        outputcx.outputarg = outputarg;

        rv = SEC_ASN1Encode(cinfo, sec_PKCS7ContentInfoTemplate,
                            sec_pkcs7_encoder_out, &outputcx);
    }

    return rv;
}

/*
 * Encode a PKCS7 object, in one shot.  All necessary components
 * of the object must already be specified.  Either the data has
 * already been included (via SetContent), or the data is detached,
 * or there is no data at all (certs-only).  The output, rather than
 * being passed to an output function as is done above, is all put
 * into a SECItem.
 *
 * "pool" specifies a pool from which to allocate the result.
 * It can be NULL, in which case memory is allocated generically.
 *
 * "dest" specifies a SECItem in which to put the result data.
 * It can be NULL, in which case the entire item is allocated, too.
 *
 * "cinfo" specifies the object to be encoded.
 *
 * "bulkkey" specifies the bulk encryption key to use.   This argument
 * can be NULL if no encryption is being done, or if the bulk key should
 * be generated internally (usually the case for EnvelopedData but never
 * for EncryptedData, which *must* provide a bulk encryption key).
 *
 * "pwfn" is a callback for getting the password which protects the
 * private key of the signer.  This argument can be NULL if it is known
 * that no signing is going to be done.
 *
 * "pwfnarg" is an opaque argument to the above callback.
 */
SECItem *
SEC_PKCS7EncodeItem(PLArenaPool *pool,
                    SECItem *dest,
                    SEC_PKCS7ContentInfo *cinfo,
                    PK11SymKey *bulkkey,
                    SECKEYGetPasswordKey pwfn,
                    void *pwfnarg)
{
    SECStatus rv;

    rv = SEC_PKCS7PrepareForEncode(cinfo, bulkkey, pwfn, pwfnarg);
    if (rv != SECSuccess)
        return NULL;

    return SEC_ASN1EncodeItem(pool, dest, cinfo, sec_PKCS7ContentInfoTemplate);
}