summaryrefslogtreecommitdiff
path: root/drivers/builtin_openssl2/crypto/asn1/tasn_enc.c
blob: f7f83e56a981405dfd172fb6f8c34c3521dec5d1 (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
/* tasn_enc.c */
/*
 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
 * 2000.
 */
/* ====================================================================
 * Copyright (c) 2000-2004 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 "cryptlib.h"
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/objects.h>

static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out,
                                 const ASN1_ITEM *it, int tag, int aclass);
static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *sk, unsigned char **out,
                            int skcontlen, const ASN1_ITEM *item,
                            int do_sort, int iclass);
static int asn1_template_ex_i2d(ASN1_VALUE **pval, unsigned char **out,
                                const ASN1_TEMPLATE *tt, int tag, int aclass);
static int asn1_item_flags_i2d(ASN1_VALUE *val, unsigned char **out,
                               const ASN1_ITEM *it, int flags);

/*
 * Top level i2d equivalents: the 'ndef' variant instructs the encoder to use
 * indefinite length constructed encoding, where appropriate
 */

int ASN1_item_ndef_i2d(ASN1_VALUE *val, unsigned char **out,
                       const ASN1_ITEM *it)
{
    return asn1_item_flags_i2d(val, out, it, ASN1_TFLG_NDEF);
}

int ASN1_item_i2d(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it)
{
    return asn1_item_flags_i2d(val, out, it, 0);
}

/*
 * Encode an ASN1 item, this is use by the standard 'i2d' function. 'out'
 * points to a buffer to output the data to. The new i2d has one additional
 * feature. If the output buffer is NULL (i.e. *out == NULL) then a buffer is
 * allocated and populated with the encoding.
 */

static int asn1_item_flags_i2d(ASN1_VALUE *val, unsigned char **out,
                               const ASN1_ITEM *it, int flags)
{
    if (out && !*out) {
        unsigned char *p, *buf;
        int len;
        len = ASN1_item_ex_i2d(&val, NULL, it, -1, flags);
        if (len <= 0)
            return len;
        buf = OPENSSL_malloc(len);
        if (!buf)
            return -1;
        p = buf;
        ASN1_item_ex_i2d(&val, &p, it, -1, flags);
        *out = buf;
        return len;
    }

    return ASN1_item_ex_i2d(&val, out, it, -1, flags);
}

/*
 * Encode an item, taking care of IMPLICIT tagging (if any). This function
 * performs the normal item handling: it can be used in external types.
 */

int ASN1_item_ex_i2d(ASN1_VALUE **pval, unsigned char **out,
                     const ASN1_ITEM *it, int tag, int aclass)
{
    const ASN1_TEMPLATE *tt = NULL;
    unsigned char *p = NULL;
    int i, seqcontlen, seqlen, ndef = 1;
    const ASN1_COMPAT_FUNCS *cf;
    const ASN1_EXTERN_FUNCS *ef;
    const ASN1_AUX *aux = it->funcs;
    ASN1_aux_cb *asn1_cb = 0;

    if ((it->itype != ASN1_ITYPE_PRIMITIVE) && !*pval)
        return 0;

    if (aux && aux->asn1_cb)
        asn1_cb = aux->asn1_cb;

    switch (it->itype) {

    case ASN1_ITYPE_PRIMITIVE:
        if (it->templates)
            return asn1_template_ex_i2d(pval, out, it->templates,
                                        tag, aclass);
        return asn1_i2d_ex_primitive(pval, out, it, tag, aclass);
        break;

    case ASN1_ITYPE_MSTRING:
        return asn1_i2d_ex_primitive(pval, out, it, -1, aclass);

    case ASN1_ITYPE_CHOICE:
        if (asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it, NULL))
            return 0;
        i = asn1_get_choice_selector(pval, it);
        if ((i >= 0) && (i < it->tcount)) {
            ASN1_VALUE **pchval;
            const ASN1_TEMPLATE *chtt;
            chtt = it->templates + i;
            pchval = asn1_get_field_ptr(pval, chtt);
            return asn1_template_ex_i2d(pchval, out, chtt, -1, aclass);
        }
        /* Fixme: error condition if selector out of range */
        if (asn1_cb && !asn1_cb(ASN1_OP_I2D_POST, pval, it, NULL))
            return 0;
        break;

    case ASN1_ITYPE_EXTERN:
        /* If new style i2d it does all the work */
        ef = it->funcs;
        return ef->asn1_ex_i2d(pval, out, it, tag, aclass);

    case ASN1_ITYPE_COMPAT:
        /* old style hackery... */
        cf = it->funcs;
        if (out)
            p = *out;
        i = cf->asn1_i2d(*pval, out);
        /*
         * Fixup for IMPLICIT tag: note this messes up for tags > 30, but so
         * did the old code. Tags > 30 are very rare anyway.
         */
        if (out && (tag != -1))
            *p = aclass | tag | (*p & V_ASN1_CONSTRUCTED);
        return i;

    case ASN1_ITYPE_NDEF_SEQUENCE:
        /* Use indefinite length constructed if requested */
        if (aclass & ASN1_TFLG_NDEF)
            ndef = 2;
        /* fall through */

    case ASN1_ITYPE_SEQUENCE:
        i = asn1_enc_restore(&seqcontlen, out, pval, it);
        /* An error occurred */
        if (i < 0)
            return 0;
        /* We have a valid cached encoding... */
        if (i > 0)
            return seqcontlen;
        /* Otherwise carry on */
        seqcontlen = 0;
        /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
        if (tag == -1) {
            tag = V_ASN1_SEQUENCE;
            /* Retain any other flags in aclass */
            aclass = (aclass & ~ASN1_TFLG_TAG_CLASS)
                | V_ASN1_UNIVERSAL;
        }
        if (asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it, NULL))
            return 0;
        /* First work out sequence content length */
        for (i = 0, tt = it->templates; i < it->tcount; tt++, i++) {
            const ASN1_TEMPLATE *seqtt;
            ASN1_VALUE **pseqval;
            seqtt = asn1_do_adb(pval, tt, 1);
            if (!seqtt)
                return 0;
            pseqval = asn1_get_field_ptr(pval, seqtt);
            /* FIXME: check for errors in enhanced version */
            seqcontlen += asn1_template_ex_i2d(pseqval, NULL, seqtt,
                                               -1, aclass);
        }

        seqlen = ASN1_object_size(ndef, seqcontlen, tag);
        if (!out)
            return seqlen;
        /* Output SEQUENCE header */
        ASN1_put_object(out, ndef, seqcontlen, tag, aclass);
        for (i = 0, tt = it->templates; i < it->tcount; tt++, i++) {
            const ASN1_TEMPLATE *seqtt;
            ASN1_VALUE **pseqval;
            seqtt = asn1_do_adb(pval, tt, 1);
            if (!seqtt)
                return 0;
            pseqval = asn1_get_field_ptr(pval, seqtt);
            /* FIXME: check for errors in enhanced version */
            asn1_template_ex_i2d(pseqval, out, seqtt, -1, aclass);
        }
        if (ndef == 2)
            ASN1_put_eoc(out);
        if (asn1_cb && !asn1_cb(ASN1_OP_I2D_POST, pval, it, NULL))
            return 0;
        return seqlen;

    default:
        return 0;

    }
    return 0;
}

int ASN1_template_i2d(ASN1_VALUE **pval, unsigned char **out,
                      const ASN1_TEMPLATE *tt)
{
    return asn1_template_ex_i2d(pval, out, tt, -1, 0);
}

static int asn1_template_ex_i2d(ASN1_VALUE **pval, unsigned char **out,
                                const ASN1_TEMPLATE *tt, int tag, int iclass)
{
    int i, ret, flags, ttag, tclass, ndef;
    flags = tt->flags;
    /*
     * Work out tag and class to use: tagging may come either from the
     * template or the arguments, not both because this would create
     * ambiguity. Additionally the iclass argument may contain some
     * additional flags which should be noted and passed down to other
     * levels.
     */
    if (flags & ASN1_TFLG_TAG_MASK) {
        /* Error if argument and template tagging */
        if (tag != -1)
            /* FIXME: error code here */
            return -1;
        /* Get tagging from template */
        ttag = tt->tag;
        tclass = flags & ASN1_TFLG_TAG_CLASS;
    } else if (tag != -1) {
        /* No template tagging, get from arguments */
        ttag = tag;
        tclass = iclass & ASN1_TFLG_TAG_CLASS;
    } else {
        ttag = -1;
        tclass = 0;
    }
    /*
     * Remove any class mask from iflag.
     */
    iclass &= ~ASN1_TFLG_TAG_CLASS;

    /*
     * At this point 'ttag' contains the outer tag to use, 'tclass' is the
     * class and iclass is any flags passed to this function.
     */

    /* if template and arguments require ndef, use it */
    if ((flags & ASN1_TFLG_NDEF) && (iclass & ASN1_TFLG_NDEF))
        ndef = 2;
    else
        ndef = 1;

    if (flags & ASN1_TFLG_SK_MASK) {
        /* SET OF, SEQUENCE OF */
        STACK_OF(ASN1_VALUE) *sk = (STACK_OF(ASN1_VALUE) *)*pval;
        int isset, sktag, skaclass;
        int skcontlen, sklen;
        ASN1_VALUE *skitem;

        if (!*pval)
            return 0;

        if (flags & ASN1_TFLG_SET_OF) {
            isset = 1;
            /* 2 means we reorder */
            if (flags & ASN1_TFLG_SEQUENCE_OF)
                isset = 2;
        } else
            isset = 0;

        /*
         * Work out inner tag value: if EXPLICIT or no tagging use underlying
         * type.
         */
        if ((ttag != -1) && !(flags & ASN1_TFLG_EXPTAG)) {
            sktag = ttag;
            skaclass = tclass;
        } else {
            skaclass = V_ASN1_UNIVERSAL;
            if (isset)
                sktag = V_ASN1_SET;
            else
                sktag = V_ASN1_SEQUENCE;
        }

        /* Determine total length of items */
        skcontlen = 0;
        for (i = 0; i < sk_ASN1_VALUE_num(sk); i++) {
            skitem = sk_ASN1_VALUE_value(sk, i);
            skcontlen += ASN1_item_ex_i2d(&skitem, NULL,
                                          ASN1_ITEM_ptr(tt->item),
                                          -1, iclass);
        }
        sklen = ASN1_object_size(ndef, skcontlen, sktag);
        /* If EXPLICIT need length of surrounding tag */
        if (flags & ASN1_TFLG_EXPTAG)
            ret = ASN1_object_size(ndef, sklen, ttag);
        else
            ret = sklen;

        if (!out)
            return ret;

        /* Now encode this lot... */
        /* EXPLICIT tag */
        if (flags & ASN1_TFLG_EXPTAG)
            ASN1_put_object(out, ndef, sklen, ttag, tclass);
        /* SET or SEQUENCE and IMPLICIT tag */
        ASN1_put_object(out, ndef, skcontlen, sktag, skaclass);
        /* And the stuff itself */
        asn1_set_seq_out(sk, out, skcontlen, ASN1_ITEM_ptr(tt->item),
                         isset, iclass);
        if (ndef == 2) {
            ASN1_put_eoc(out);
            if (flags & ASN1_TFLG_EXPTAG)
                ASN1_put_eoc(out);
        }

        return ret;
    }

    if (flags & ASN1_TFLG_EXPTAG) {
        /* EXPLICIT tagging */
        /* Find length of tagged item */
        i = ASN1_item_ex_i2d(pval, NULL, ASN1_ITEM_ptr(tt->item), -1, iclass);
        if (!i)
            return 0;
        /* Find length of EXPLICIT tag */
        ret = ASN1_object_size(ndef, i, ttag);
        if (out) {
            /* Output tag and item */
            ASN1_put_object(out, ndef, i, ttag, tclass);
            ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), -1, iclass);
            if (ndef == 2)
                ASN1_put_eoc(out);
        }
        return ret;
    }

    /* Either normal or IMPLICIT tagging: combine class and flags */
    return ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item),
                            ttag, tclass | iclass);

}

/* Temporary structure used to hold DER encoding of items for SET OF */

typedef struct {
    unsigned char *data;
    int length;
    ASN1_VALUE *field;
} DER_ENC;

static int der_cmp(const void *a, const void *b)
{
    const DER_ENC *d1 = a, *d2 = b;
    int cmplen, i;
    cmplen = (d1->length < d2->length) ? d1->length : d2->length;
    i = memcmp(d1->data, d2->data, cmplen);
    if (i)
        return i;
    return d1->length - d2->length;
}

/* Output the content octets of SET OF or SEQUENCE OF */

static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *sk, unsigned char **out,
                            int skcontlen, const ASN1_ITEM *item,
                            int do_sort, int iclass)
{
    int i;
    ASN1_VALUE *skitem;
    unsigned char *tmpdat = NULL, *p = NULL;
    DER_ENC *derlst = NULL, *tder;
    if (do_sort) {
        /* Don't need to sort less than 2 items */
        if (sk_ASN1_VALUE_num(sk) < 2)
            do_sort = 0;
        else {
            derlst = OPENSSL_malloc(sk_ASN1_VALUE_num(sk)
                                    * sizeof(*derlst));
            if (!derlst)
                return 0;
            tmpdat = OPENSSL_malloc(skcontlen);
            if (!tmpdat) {
                OPENSSL_free(derlst);
                return 0;
            }
        }
    }
    /* If not sorting just output each item */
    if (!do_sort) {
        for (i = 0; i < sk_ASN1_VALUE_num(sk); i++) {
            skitem = sk_ASN1_VALUE_value(sk, i);
            ASN1_item_ex_i2d(&skitem, out, item, -1, iclass);
        }
        return 1;
    }
    p = tmpdat;

    /* Doing sort: build up a list of each member's DER encoding */
    for (i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++) {
        skitem = sk_ASN1_VALUE_value(sk, i);
        tder->data = p;
        tder->length = ASN1_item_ex_i2d(&skitem, &p, item, -1, iclass);
        tder->field = skitem;
    }

    /* Now sort them */
    qsort(derlst, sk_ASN1_VALUE_num(sk), sizeof(*derlst), der_cmp);
    /* Output sorted DER encoding */
    p = *out;
    for (i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++) {
        memcpy(p, tder->data, tder->length);
        p += tder->length;
    }
    *out = p;
    /* If do_sort is 2 then reorder the STACK */
    if (do_sort == 2) {
        for (i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++)
            (void)sk_ASN1_VALUE_set(sk, i, tder->field);
    }
    OPENSSL_free(derlst);
    OPENSSL_free(tmpdat);
    return 1;
}

static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out,
                                 const ASN1_ITEM *it, int tag, int aclass)
{
    int len;
    int utype;
    int usetag;
    int ndef = 0;

    utype = it->utype;

    /*
     * Get length of content octets and maybe find out the underlying type.
     */

    len = asn1_ex_i2c(pval, NULL, &utype, it);

    /*
     * If SEQUENCE, SET or OTHER then header is included in pseudo content
     * octets so don't include tag+length. We need to check here because the
     * call to asn1_ex_i2c() could change utype.
     */
    if ((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) ||
        (utype == V_ASN1_OTHER))
        usetag = 0;
    else
        usetag = 1;

    /* -1 means omit type */

    if (len == -1)
        return 0;

    /* -2 return is special meaning use ndef */
    if (len == -2) {
        ndef = 2;
        len = 0;
    }

    /* If not implicitly tagged get tag from underlying type */
    if (tag == -1)
        tag = utype;

    /* Output tag+length followed by content octets */
    if (out) {
        if (usetag)
            ASN1_put_object(out, ndef, len, tag, aclass);
        asn1_ex_i2c(pval, *out, &utype, it);
        if (ndef)
            ASN1_put_eoc(out);
        else
            *out += len;
    }

    if (usetag)
        return ASN1_object_size(ndef, len, tag);
    return len;
}

/* Produce content octets from a structure */

int asn1_ex_i2c(ASN1_VALUE **pval, unsigned char *cout, int *putype,
                const ASN1_ITEM *it)
{
    ASN1_BOOLEAN *tbool = NULL;
    ASN1_STRING *strtmp;
    ASN1_OBJECT *otmp;
    int utype;
    const unsigned char *cont;
    unsigned char c;
    int len;
    const ASN1_PRIMITIVE_FUNCS *pf;
    pf = it->funcs;
    if (pf && pf->prim_i2c)
        return pf->prim_i2c(pval, cout, putype, it);

    /* Should type be omitted? */
    if ((it->itype != ASN1_ITYPE_PRIMITIVE)
        || (it->utype != V_ASN1_BOOLEAN)) {
        if (!*pval)
            return -1;
    }

    if (it->itype == ASN1_ITYPE_MSTRING) {
        /* If MSTRING type set the underlying type */
        strtmp = (ASN1_STRING *)*pval;
        utype = strtmp->type;
        *putype = utype;
    } else if (it->utype == V_ASN1_ANY) {
        /* If ANY set type and pointer to value */
        ASN1_TYPE *typ;
        typ = (ASN1_TYPE *)*pval;
        utype = typ->type;
        *putype = utype;
        pval = &typ->value.asn1_value;
    } else
        utype = *putype;

    switch (utype) {
    case V_ASN1_OBJECT:
        otmp = (ASN1_OBJECT *)*pval;
        cont = otmp->data;
        len = otmp->length;
        break;

    case V_ASN1_NULL:
        cont = NULL;
        len = 0;
        break;

    case V_ASN1_BOOLEAN:
        tbool = (ASN1_BOOLEAN *)pval;
        if (*tbool == -1)
            return -1;
        if (it->utype != V_ASN1_ANY) {
            /*
             * Default handling if value == size field then omit
             */
            if (*tbool && (it->size > 0))
                return -1;
            if (!*tbool && !it->size)
                return -1;
        }
        c = (unsigned char)*tbool;
        cont = &c;
        len = 1;
        break;

    case V_ASN1_BIT_STRING:
        return i2c_ASN1_BIT_STRING((ASN1_BIT_STRING *)*pval,
                                   cout ? &cout : NULL);
        break;

    case V_ASN1_INTEGER:
    case V_ASN1_ENUMERATED:
        /*
         * These are all have the same content format as ASN1_INTEGER
         */
        return i2c_ASN1_INTEGER((ASN1_INTEGER *)*pval, cout ? &cout : NULL);
        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_SEQUENCE:
    case V_ASN1_SET:
    default:
        /* All based on ASN1_STRING and handled the same */
        strtmp = (ASN1_STRING *)*pval;
        /* Special handling for NDEF */
        if ((it->size == ASN1_TFLG_NDEF)
            && (strtmp->flags & ASN1_STRING_FLAG_NDEF)) {
            if (cout) {
                strtmp->data = cout;
                strtmp->length = 0;
            }
            /* Special return code */
            return -2;
        }
        cont = strtmp->data;
        len = strtmp->length;

        break;

    }
    if (cout && len)
        memcpy(cout, cont, len);
    return len;
}