summaryrefslogtreecommitdiff
path: root/drivers/builtin_openssl2/crypto/asn1/tasn_dec.c
blob: 6bdcd5c542ca56a101e5a267fbb137de8966c892 (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
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
/* tasn_dec.c */
/*
 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
 * 2000.
 */
/* ====================================================================
 * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stddef.h>
#include <string.h>
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/objects.h>
#include <openssl/buffer.h>
#include <openssl/err.h>

static int asn1_check_eoc(const unsigned char **in, long len);
static int asn1_find_end(const unsigned char **in, long len, char inf);

static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
                        char inf, int tag, int aclass, int depth);

static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);

static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
                           char *inf, char *cst,
                           const unsigned char **in, long len,
                           int exptag, int expclass, char opt, ASN1_TLC *ctx);

static int asn1_template_ex_d2i(ASN1_VALUE **pval,
                                const unsigned char **in, long len,
                                const ASN1_TEMPLATE *tt, char opt,
                                ASN1_TLC *ctx);
static int asn1_template_noexp_d2i(ASN1_VALUE **val,
                                   const unsigned char **in, long len,
                                   const ASN1_TEMPLATE *tt, char opt,
                                   ASN1_TLC *ctx);
static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
                                 const unsigned char **in, long len,
                                 const ASN1_ITEM *it,
                                 int tag, int aclass, char opt,
                                 ASN1_TLC *ctx);

/* Table to convert tags to bit values, used for MSTRING type */
static const unsigned long tag2bit[32] = {
    /* tags  0 -  3 */
    0, 0, 0, B_ASN1_BIT_STRING,
    /* tags  4- 7 */
    B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,
    /* tags  8-11 */
    B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
    /* tags 12-15 */
    B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
    /* tags 16-19 */
    B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING,
    /* tags 20-22 */
    B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING,
    /* tags 23-24 */
    B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
    /* tags 25-27 */
    B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING,
    /* tags 28-31 */
    B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN,
};

unsigned long ASN1_tag2bit(int tag)
{
    if ((tag < 0) || (tag > 30))
        return 0;
    return tag2bit[tag];
}

/* Macro to initialize and invalidate the cache */

#define asn1_tlc_clear(c)       if (c) (c)->valid = 0
/* Version to avoid compiler warning about 'c' always non-NULL */
#define asn1_tlc_clear_nc(c)    (c)->valid = 0

/*
 * Decode an ASN1 item, this currently behaves just like a standard 'd2i'
 * function. 'in' points to a buffer to read the data from, in future we
 * will have more advanced versions that can input data a piece at a time and
 * this will simply be a special case.
 */

ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
                          const unsigned char **in, long len,
                          const ASN1_ITEM *it)
{
    ASN1_TLC c;
    ASN1_VALUE *ptmpval = NULL;
    if (!pval)
        pval = &ptmpval;
    asn1_tlc_clear_nc(&c);
    if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
        return *pval;
    return NULL;
}

int ASN1_template_d2i(ASN1_VALUE **pval,
                      const unsigned char **in, long len,
                      const ASN1_TEMPLATE *tt)
{
    ASN1_TLC c;
    asn1_tlc_clear_nc(&c);
    return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
}

/*
 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
 * tag mismatch return -1 to handle OPTIONAL
 */

int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
                     const ASN1_ITEM *it,
                     int tag, int aclass, char opt, ASN1_TLC *ctx)
{
    const ASN1_TEMPLATE *tt, *errtt = NULL;
    const ASN1_COMPAT_FUNCS *cf;
    const ASN1_EXTERN_FUNCS *ef;
    const ASN1_AUX *aux = it->funcs;
    ASN1_aux_cb *asn1_cb;
    const unsigned char *p = NULL, *q;
    unsigned char *wp = NULL;   /* BIG FAT WARNING! BREAKS CONST WHERE USED */
    unsigned char imphack = 0, oclass;
    char seq_eoc, seq_nolen, cst, isopt;
    long tmplen;
    int i;
    int otag;
    int ret = 0;
    ASN1_VALUE **pchptr, *ptmpval;
    int combine = aclass & ASN1_TFLG_COMBINE;
    aclass &= ~ASN1_TFLG_COMBINE;
    if (!pval)
        return 0;
    if (aux && aux->asn1_cb)
        asn1_cb = aux->asn1_cb;
    else
        asn1_cb = 0;

    switch (it->itype) {
    case ASN1_ITYPE_PRIMITIVE:
        if (it->templates) {
            /*
             * tagging or OPTIONAL is currently illegal on an item template
             * because the flags can't get passed down. In practice this
             * isn't a problem: we include the relevant flags from the item
             * template in the template itself.
             */
            if ((tag != -1) || opt) {
                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                        ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
                goto err;
            }
            return asn1_template_ex_d2i(pval, in, len,
                                        it->templates, opt, ctx);
        }
        return asn1_d2i_ex_primitive(pval, in, len, it,
                                     tag, aclass, opt, ctx);
        break;

    case ASN1_ITYPE_MSTRING:
        p = *in;
        /* Just read in tag and class */
        ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
                              &p, len, -1, 0, 1, ctx);
        if (!ret) {
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
            goto err;
        }

        /* Must be UNIVERSAL class */
        if (oclass != V_ASN1_UNIVERSAL) {
            /* If OPTIONAL, assume this is OK */
            if (opt)
                return -1;
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL);
            goto err;
        }
        /* Check tag matches bit map */
        if (!(ASN1_tag2bit(otag) & it->utype)) {
            /* If OPTIONAL, assume this is OK */
            if (opt)
                return -1;
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_WRONG_TAG);
            goto err;
        }
        return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx);

    case ASN1_ITYPE_EXTERN:
        /* Use new style d2i */
        ef = it->funcs;
        return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx);

    case ASN1_ITYPE_COMPAT:
        /* we must resort to old style evil hackery */
        cf = it->funcs;

        /* If OPTIONAL see if it is there */
        if (opt) {
            int exptag;
            p = *in;
            if (tag == -1)
                exptag = it->utype;
            else
                exptag = tag;
            /*
             * Don't care about anything other than presence of expected tag
             */

            ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
                                  &p, len, exptag, aclass, 1, ctx);
            if (!ret) {
                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
                goto err;
            }
            if (ret == -1)
                return -1;
        }

        /*
         * This is the old style evil hack IMPLICIT handling: since the
         * underlying code is expecting a tag and class other than the one
         * present we change the buffer temporarily then change it back
         * afterwards. This doesn't and never did work for tags > 30. Yes
         * this is *horrible* but it is only needed for old style d2i which
         * will hopefully not be around for much longer. FIXME: should copy
         * the buffer then modify it so the input buffer can be const: we
         * should *always* copy because the old style d2i might modify the
         * buffer.
         */

        if (tag != -1) {
            wp = *(unsigned char **)in;
            imphack = *wp;
            if (p == NULL) {
                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
                goto err;
            }
            *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
                                  | it->utype);
        }

        ptmpval = cf->asn1_d2i(pval, in, len);

        if (tag != -1)
            *wp = imphack;

        if (ptmpval)
            return 1;

        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
        goto err;

    case ASN1_ITYPE_CHOICE:
        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
            goto auxerr;
        if (*pval) {
            /* Free up and zero CHOICE value if initialised */
            i = asn1_get_choice_selector(pval, it);
            if ((i >= 0) && (i < it->tcount)) {
                tt = it->templates + i;
                pchptr = asn1_get_field_ptr(pval, tt);
                ASN1_template_free(pchptr, tt);
                asn1_set_choice_selector(pval, -1, it);
            }
        } else if (!ASN1_item_ex_new(pval, it)) {
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
            goto err;
        }
        /* CHOICE type, try each possibility in turn */
        p = *in;
        for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
            pchptr = asn1_get_field_ptr(pval, tt);
            /*
             * We mark field as OPTIONAL so its absence can be recognised.
             */
            ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
            /* If field not present, try the next one */
            if (ret == -1)
                continue;
            /* If positive return, read OK, break loop */
            if (ret > 0)
                break;
            /* Otherwise must be an ASN1 parsing error */
            errtt = tt;
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
            goto err;
        }

        /* Did we fall off the end without reading anything? */
        if (i == it->tcount) {
            /* If OPTIONAL, this is OK */
            if (opt) {
                /* Free and zero it */
                ASN1_item_ex_free(pval, it);
                return -1;
            }
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE);
            goto err;
        }

        asn1_set_choice_selector(pval, i, it);
        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
            goto auxerr;
        *in = p;
        return 1;

    case ASN1_ITYPE_NDEF_SEQUENCE:
    case ASN1_ITYPE_SEQUENCE:
        p = *in;
        tmplen = len;

        /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
        if (tag == -1) {
            tag = V_ASN1_SEQUENCE;
            aclass = V_ASN1_UNIVERSAL;
        }
        /* Get SEQUENCE length and update len, p */
        ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
                              &p, len, tag, aclass, opt, ctx);
        if (!ret) {
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
            goto err;
        } else if (ret == -1)
            return -1;
        if (aux && (aux->flags & ASN1_AFLG_BROKEN)) {
            len = tmplen - (p - *in);
            seq_nolen = 1;
        }
        /* If indefinite we don't do a length check */
        else
            seq_nolen = seq_eoc;
        if (!cst) {
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
            goto err;
        }

        if (!*pval && !ASN1_item_ex_new(pval, it)) {
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
            goto err;
        }

        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
            goto auxerr;

        /* Free up and zero any ADB found */
        for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
            if (tt->flags & ASN1_TFLG_ADB_MASK) {
                const ASN1_TEMPLATE *seqtt;
                ASN1_VALUE **pseqval;
                seqtt = asn1_do_adb(pval, tt, 1);
                pseqval = asn1_get_field_ptr(pval, seqtt);
                ASN1_template_free(pseqval, seqtt);
            }
        }

        /* Get each field entry */
        for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
            const ASN1_TEMPLATE *seqtt;
            ASN1_VALUE **pseqval;
            seqtt = asn1_do_adb(pval, tt, 1);
            if (!seqtt)
                goto err;
            pseqval = asn1_get_field_ptr(pval, seqtt);
            /* Have we ran out of data? */
            if (!len)
                break;
            q = p;
            if (asn1_check_eoc(&p, len)) {
                if (!seq_eoc) {
                    ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_UNEXPECTED_EOC);
                    goto err;
                }
                len -= p - q;
                seq_eoc = 0;
                q = p;
                break;
            }
            /*
             * This determines the OPTIONAL flag value. The field cannot be
             * omitted if it is the last of a SEQUENCE and there is still
             * data to be read. This isn't strictly necessary but it
             * increases efficiency in some cases.
             */
            if (i == (it->tcount - 1))
                isopt = 0;
            else
                isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
            /*
             * attempt to read in field, allowing each to be OPTIONAL
             */

            ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx);
            if (!ret) {
                errtt = seqtt;
                goto err;
            } else if (ret == -1) {
                /*
                 * OPTIONAL component absent. Free and zero the field.
                 */
                ASN1_template_free(pseqval, seqtt);
                continue;
            }
            /* Update length */
            len -= p - q;
        }

        /* Check for EOC if expecting one */
        if (seq_eoc && !asn1_check_eoc(&p, len)) {
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
            goto err;
        }
        /* Check all data read */
        if (!seq_nolen && len) {
            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH);
            goto err;
        }

        /*
         * If we get here we've got no more data in the SEQUENCE, however we
         * may not have read all fields so check all remaining are OPTIONAL
         * and clear any that are.
         */
        for (; i < it->tcount; tt++, i++) {
            const ASN1_TEMPLATE *seqtt;
            seqtt = asn1_do_adb(pval, tt, 1);
            if (!seqtt)
                goto err;
            if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
                ASN1_VALUE **pseqval;
                pseqval = asn1_get_field_ptr(pval, seqtt);
                ASN1_template_free(pseqval, seqtt);
            } else {
                errtt = seqtt;
                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_FIELD_MISSING);
                goto err;
            }
        }
        /* Save encoding */
        if (!asn1_enc_save(pval, *in, p - *in, it))
            goto auxerr;
        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
            goto auxerr;
        *in = p;
        return 1;

    default:
        return 0;
    }
 auxerr:
    ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
 err:
    if (combine == 0)
        ASN1_item_ex_free(pval, it);
    if (errtt)
        ERR_add_error_data(4, "Field=", errtt->field_name,
                           ", Type=", it->sname);
    else
        ERR_add_error_data(2, "Type=", it->sname);
    return 0;
}

/*
 * Templates are handled with two separate functions. One handles any
 * EXPLICIT tag and the other handles the rest.
 */

static int asn1_template_ex_d2i(ASN1_VALUE **val,
                                const unsigned char **in, long inlen,
                                const ASN1_TEMPLATE *tt, char opt,
                                ASN1_TLC *ctx)
{
    int flags, aclass;
    int ret;
    long len;
    const unsigned char *p, *q;
    char exp_eoc;
    if (!val)
        return 0;
    flags = tt->flags;
    aclass = flags & ASN1_TFLG_TAG_CLASS;

    p = *in;

    /* Check if EXPLICIT tag expected */
    if (flags & ASN1_TFLG_EXPTAG) {
        char cst;
        /*
         * Need to work out amount of data available to the inner content and
         * where it starts: so read in EXPLICIT header to get the info.
         */
        ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
                              &p, inlen, tt->tag, aclass, opt, ctx);
        q = p;
        if (!ret) {
            ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
            return 0;
        } else if (ret == -1)
            return -1;
        if (!cst) {
            ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
                    ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
            return 0;
        }
        /* We've found the field so it can't be OPTIONAL now */
        ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
        if (!ret) {
            ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
            return 0;
        }
        /* We read the field in OK so update length */
        len -= p - q;
        if (exp_eoc) {
            /* If NDEF we must have an EOC here */
            if (!asn1_check_eoc(&p, len)) {
                ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC);
                goto err;
            }
        } else {
            /*
             * Otherwise we must hit the EXPLICIT tag end or its an error
             */
            if (len) {
                ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
                        ASN1_R_EXPLICIT_LENGTH_MISMATCH);
                goto err;
            }
        }
    } else
        return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx);

    *in = p;
    return 1;

 err:
    ASN1_template_free(val, tt);
    return 0;
}

static int asn1_template_noexp_d2i(ASN1_VALUE **val,
                                   const unsigned char **in, long len,
                                   const ASN1_TEMPLATE *tt, char opt,
                                   ASN1_TLC *ctx)
{
    int flags, aclass;
    int ret;
    const unsigned char *p, *q;
    if (!val)
        return 0;
    flags = tt->flags;
    aclass = flags & ASN1_TFLG_TAG_CLASS;

    p = *in;
    q = p;

    if (flags & ASN1_TFLG_SK_MASK) {
        /* SET OF, SEQUENCE OF */
        int sktag, skaclass;
        char sk_eoc;
        /* First work out expected inner tag value */
        if (flags & ASN1_TFLG_IMPTAG) {
            sktag = tt->tag;
            skaclass = aclass;
        } else {
            skaclass = V_ASN1_UNIVERSAL;
            if (flags & ASN1_TFLG_SET_OF)
                sktag = V_ASN1_SET;
            else
                sktag = V_ASN1_SEQUENCE;
        }
        /* Get the tag */
        ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
                              &p, len, sktag, skaclass, opt, ctx);
        if (!ret) {
            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
            return 0;
        } else if (ret == -1)
            return -1;
        if (!*val)
            *val = (ASN1_VALUE *)sk_new_null();
        else {
            /*
             * We've got a valid STACK: free up any items present
             */
            STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val;
            ASN1_VALUE *vtmp;
            while (sk_ASN1_VALUE_num(sktmp) > 0) {
                vtmp = sk_ASN1_VALUE_pop(sktmp);
                ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item));
            }
        }

        if (!*val) {
            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
            goto err;
        }

        /* Read as many items as we can */
        while (len > 0) {
            ASN1_VALUE *skfield;
            q = p;
            /* See if EOC found */
            if (asn1_check_eoc(&p, len)) {
                if (!sk_eoc) {
                    ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
                            ASN1_R_UNEXPECTED_EOC);
                    goto err;
                }
                len -= p - q;
                sk_eoc = 0;
                break;
            }
            skfield = NULL;
            if (!ASN1_item_ex_d2i(&skfield, &p, len,
                                  ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx)) {
                ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
                        ERR_R_NESTED_ASN1_ERROR);
                goto err;
            }
            len -= p - q;
            if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) {
                ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
                goto err;
            }
        }
        if (sk_eoc) {
            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
            goto err;
        }
    } else if (flags & ASN1_TFLG_IMPTAG) {
        /* IMPLICIT tagging */
        ret = ASN1_item_ex_d2i(val, &p, len,
                               ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt,
                               ctx);
        if (!ret) {
            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
            goto err;
        } else if (ret == -1)
            return -1;
    } else {
        /* Nothing special */
        ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
                               -1, tt->flags & ASN1_TFLG_COMBINE, opt, ctx);
        if (!ret) {
            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
            goto err;
        } else if (ret == -1)
            return -1;
    }

    *in = p;
    return 1;

 err:
    ASN1_template_free(val, tt);
    return 0;
}

static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
                                 const unsigned char **in, long inlen,
                                 const ASN1_ITEM *it,
                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
{
    int ret = 0, utype;
    long plen;
    char cst, inf, free_cont = 0;
    const unsigned char *p;
    BUF_MEM buf = { 0, NULL, 0 };
    const unsigned char *cont = NULL;
    long len;
    if (!pval) {
        ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
        return 0;               /* Should never happen */
    }

    if (it->itype == ASN1_ITYPE_MSTRING) {
        utype = tag;
        tag = -1;
    } else
        utype = it->utype;

    if (utype == V_ASN1_ANY) {
        /* If type is ANY need to figure out type from tag */
        unsigned char oclass;
        if (tag >= 0) {
            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY);
            return 0;
        }
        if (opt) {
            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
                    ASN1_R_ILLEGAL_OPTIONAL_ANY);
            return 0;
        }
        p = *in;
        ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
                              &p, inlen, -1, 0, 0, ctx);
        if (!ret) {
            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
            return 0;
        }
        if (oclass != V_ASN1_UNIVERSAL)
            utype = V_ASN1_OTHER;
    }
    if (tag == -1) {
        tag = utype;
        aclass = V_ASN1_UNIVERSAL;
    }
    p = *in;
    /* Check header */
    ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
                          &p, inlen, tag, aclass, opt, ctx);
    if (!ret) {
        ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
        return 0;
    } else if (ret == -1)
        return -1;
    ret = 0;
    /* SEQUENCE, SET and "OTHER" are left in encoded form */
    if ((utype == V_ASN1_SEQUENCE)
        || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) {
        /*
         * Clear context cache for type OTHER because the auto clear when we
         * have a exact match wont work
         */
        if (utype == V_ASN1_OTHER) {
            asn1_tlc_clear(ctx);
        }
        /* SEQUENCE and SET must be constructed */
        else if (!cst) {
            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
                    ASN1_R_TYPE_NOT_CONSTRUCTED);
            return 0;
        }

        cont = *in;
        /* If indefinite length constructed find the real end */
        if (inf) {
            if (!asn1_find_end(&p, plen, inf))
                goto err;
            len = p - cont;
        } else {
            len = p - cont + plen;
            p += plen;
        }
    } else if (cst) {
        if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
            || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
            || utype == V_ASN1_ENUMERATED) {
            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE);
            return 0;
        }

        /* Free any returned 'buf' content */
        free_cont = 1;
        /*
         * Should really check the internal tags are correct but some things
         * may get this wrong. The relevant specs say that constructed string
         * types should be OCTET STRINGs internally irrespective of the type.
         * So instead just check for UNIVERSAL class and ignore the tag.
         */
        if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) {
            goto err;
        }
        len = buf.length;
        /* Append a final null to string */
        if (!BUF_MEM_grow_clean(&buf, len + 1)) {
            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE);
            goto err;
        }
        buf.data[len] = 0;
        cont = (const unsigned char *)buf.data;
    } else {
        cont = p;
        len = plen;
        p += plen;
    }

    /* We now have content length and type: translate into a structure */
    /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */
    if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
        goto err;

    *in = p;
    ret = 1;
 err:
    if (free_cont && buf.data)
        OPENSSL_free(buf.data);
    return ret;
}

/* Translate ASN1 content octets into a structure */

int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
                int utype, char *free_cont, const ASN1_ITEM *it)
{
    ASN1_VALUE **opval = NULL;
    ASN1_STRING *stmp;
    ASN1_TYPE *typ = NULL;
    int ret = 0;
    const ASN1_PRIMITIVE_FUNCS *pf;
    ASN1_INTEGER **tint;
    pf = it->funcs;

    if (pf && pf->prim_c2i)
        return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
    /* If ANY type clear type and set pointer to internal value */
    if (it->utype == V_ASN1_ANY) {
        if (!*pval) {
            typ = ASN1_TYPE_new();
            if (typ == NULL)
                goto err;
            *pval = (ASN1_VALUE *)typ;
        } else
            typ = (ASN1_TYPE *)*pval;

        if (utype != typ->type)
            ASN1_TYPE_set(typ, utype, NULL);
        opval = pval;
        pval = &typ->value.asn1_value;
    }
    switch (utype) {
    case V_ASN1_OBJECT:
        if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
            goto err;
        break;

    case V_ASN1_NULL:
        if (len) {
            ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH);
            goto err;
        }
        *pval = (ASN1_VALUE *)1;
        break;

    case V_ASN1_BOOLEAN:
        if (len != 1) {
            ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
            goto err;
        } else {
            ASN1_BOOLEAN *tbool;
            tbool = (ASN1_BOOLEAN *)pval;
            *tbool = *cont;
        }
        break;

    case V_ASN1_BIT_STRING:
        if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
            goto err;
        break;

    case V_ASN1_INTEGER:
    case V_ASN1_ENUMERATED:
        tint = (ASN1_INTEGER **)pval;
        if (!c2i_ASN1_INTEGER(tint, &cont, len))
            goto err;
        /* Fixup type to match the expected form */
        (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
        break;

    case V_ASN1_OCTET_STRING:
    case V_ASN1_NUMERICSTRING:
    case V_ASN1_PRINTABLESTRING:
    case V_ASN1_T61STRING:
    case V_ASN1_VIDEOTEXSTRING:
    case V_ASN1_IA5STRING:
    case V_ASN1_UTCTIME:
    case V_ASN1_GENERALIZEDTIME:
    case V_ASN1_GRAPHICSTRING:
    case V_ASN1_VISIBLESTRING:
    case V_ASN1_GENERALSTRING:
    case V_ASN1_UNIVERSALSTRING:
    case V_ASN1_BMPSTRING:
    case V_ASN1_UTF8STRING:
    case V_ASN1_OTHER:
    case V_ASN1_SET:
    case V_ASN1_SEQUENCE:
    default:
        if (utype == V_ASN1_BMPSTRING && (len & 1)) {
            ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
            goto err;
        }
        if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
            ASN1err(ASN1_F_ASN1_EX_C2I,
                    ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
            goto err;
        }
        /* All based on ASN1_STRING and handled the same */
        if (!*pval) {
            stmp = ASN1_STRING_type_new(utype);
            if (!stmp) {
                ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            *pval = (ASN1_VALUE *)stmp;
        } else {
            stmp = (ASN1_STRING *)*pval;
            stmp->type = utype;
        }
        /* If we've already allocated a buffer use it */
        if (*free_cont) {
            if (stmp->data)
                OPENSSL_free(stmp->data);
            stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
            stmp->length = len;
            *free_cont = 0;
        } else {
            if (!ASN1_STRING_set(stmp, cont, len)) {
                ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
                ASN1_STRING_free(stmp);
                *pval = NULL;
                goto err;
            }
        }
        break;
    }
    /* If ASN1_ANY and NULL type fix up value */
    if (typ && (utype == V_ASN1_NULL))
        typ->value.ptr = NULL;

    ret = 1;
 err:
    if (!ret) {
        ASN1_TYPE_free(typ);
        if (opval)
            *opval = NULL;
    }
    return ret;
}

/*
 * This function finds the end of an ASN1 structure when passed its maximum
 * length, whether it is indefinite length and a pointer to the content. This
 * is more efficient than calling asn1_collect because it does not recurse on
 * each indefinite length header.
 */

static int asn1_find_end(const unsigned char **in, long len, char inf)
{
    int expected_eoc;
    long plen;
    const unsigned char *p = *in, *q;
    /* If not indefinite length constructed just add length */
    if (inf == 0) {
        *in += len;
        return 1;
    }
    expected_eoc = 1;
    /*
     * Indefinite length constructed form. Find the end when enough EOCs are
     * found. If more indefinite length constructed headers are encountered
     * increment the expected eoc count otherwise just skip to the end of the
     * data.
     */
    while (len > 0) {
        if (asn1_check_eoc(&p, len)) {
            expected_eoc--;
            if (expected_eoc == 0)
                break;
            len -= 2;
            continue;
        }
        q = p;
        /* Just read in a header: only care about the length */
        if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
                             -1, 0, 0, NULL)) {
            ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
            return 0;
        }
        if (inf)
            expected_eoc++;
        else
            p += plen;
        len -= p - q;
    }
    if (expected_eoc) {
        ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
        return 0;
    }
    *in = p;
    return 1;
}

/*
 * This function collects the asn1 data from a constructred string type into
 * a buffer. The values of 'in' and 'len' should refer to the contents of the
 * constructed type and 'inf' should be set if it is indefinite length.
 */

#ifndef ASN1_MAX_STRING_NEST
/*
 * This determines how many levels of recursion are permitted in ASN1 string
 * types. If it is not limited stack overflows can occur. If set to zero no
 * recursion is allowed at all. Although zero should be adequate examples
 * exist that require a value of 1. So 5 should be more than enough.
 */
# define ASN1_MAX_STRING_NEST 5
#endif

static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
                        char inf, int tag, int aclass, int depth)
{
    const unsigned char *p, *q;
    long plen;
    char cst, ininf;
    p = *in;
    inf &= 1;
    /*
     * If no buffer and not indefinite length constructed just pass over the
     * encoded data
     */
    if (!buf && !inf) {
        *in += len;
        return 1;
    }
    while (len > 0) {
        q = p;
        /* Check for EOC */
        if (asn1_check_eoc(&p, len)) {
            /*
             * EOC is illegal outside indefinite length constructed form
             */
            if (!inf) {
                ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC);
                return 0;
            }
            inf = 0;
            break;
        }

        if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
                             len, tag, aclass, 0, NULL)) {
            ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
            return 0;
        }

        /* If indefinite length constructed update max length */
        if (cst) {
            if (depth >= ASN1_MAX_STRING_NEST) {
                ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
                return 0;
            }
            if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1))
                return 0;
        } else if (plen && !collect_data(buf, &p, plen))
            return 0;
        len -= p - q;
    }
    if (inf) {
        ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
        return 0;
    }
    *in = p;
    return 1;
}

static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
{
    int len;
    if (buf) {
        len = buf->length;
        if (!BUF_MEM_grow_clean(buf, len + plen)) {
            ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
            return 0;
        }
        memcpy(buf->data + len, *p, plen);
    }
    *p += plen;
    return 1;
}

/* Check for ASN1 EOC and swallow it if found */

static int asn1_check_eoc(const unsigned char **in, long len)
{
    const unsigned char *p;
    if (len < 2)
        return 0;
    p = *in;
    if (!p[0] && !p[1]) {
        *in += 2;
        return 1;
    }
    return 0;
}

/*
 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the
 * length for indefinite length constructed form, we don't know the exact
 * length but we can set an upper bound to the amount of data available minus
 * the header length just read.
 */

static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
                           char *inf, char *cst,
                           const unsigned char **in, long len,
                           int exptag, int expclass, char opt, ASN1_TLC *ctx)
{
    int i;
    int ptag, pclass;
    long plen;
    const unsigned char *p, *q;
    p = *in;
    q = p;

    if (ctx && ctx->valid) {
        i = ctx->ret;
        plen = ctx->plen;
        pclass = ctx->pclass;
        ptag = ctx->ptag;
        p += ctx->hdrlen;
    } else {
        i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
        if (ctx) {
            ctx->ret = i;
            ctx->plen = plen;
            ctx->pclass = pclass;
            ctx->ptag = ptag;
            ctx->hdrlen = p - q;
            ctx->valid = 1;
            /*
             * If definite length, and no error, length + header can't exceed
             * total amount of data available.
             */
            if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) {
                ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG);
                asn1_tlc_clear(ctx);
                return 0;
            }
        }
    }

    if (i & 0x80) {
        ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
        asn1_tlc_clear(ctx);
        return 0;
    }
    if (exptag >= 0) {
        if ((exptag != ptag) || (expclass != pclass)) {
            /*
             * If type is OPTIONAL, not an error: indicate missing type.
             */
            if (opt)
                return -1;
            asn1_tlc_clear(ctx);
            ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
            return 0;
        }
        /*
         * We have a tag and class match: assume we are going to do something
         * with it
         */
        asn1_tlc_clear(ctx);
    }

    if (i & 1)
        plen = len - (p - q);

    if (inf)
        *inf = i & 1;

    if (cst)
        *cst = i & V_ASN1_CONSTRUCTED;

    if (olen)
        *olen = plen;

    if (oclass)
        *oclass = pclass;

    if (otag)
        *otag = ptag;

    *in = p;
    return 1;
}