1/*
2 * Copyright (c) 1997 - 2006 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "gen_locl.h"
35#include "lex.h"
36
37RCSID("$Id$");
38
39static void
40decode_primitive (const char *typename, const char *name, const char *forwstr)
41{
42#if 0
43    fprintf (codefile,
44	     "e = decode_%s(p, len, %s, &l);\n"
45	     "%s;\n",
46	     typename,
47	     name,
48	     forwstr);
49#else
50    fprintf (codefile,
51	     "e = der_get_%s(p, len, %s, &l);\n"
52	     "if(e) %s;\np += l; len -= l; ret += l;\n",
53	     typename,
54	     name,
55	     forwstr);
56#endif
57}
58
59static void
60find_tag (const Type *t,
61	  Der_class *cl, Der_type *ty, unsigned *tag)
62{
63    switch (t->type) {
64    case TBitString:
65	*cl  = ASN1_C_UNIV;
66	*ty  = PRIM;
67	*tag = UT_BitString;
68	break;
69    case TBoolean:
70	*cl  = ASN1_C_UNIV;
71	*ty  = PRIM;
72	*tag = UT_Boolean;
73	break;
74    case TChoice:
75	errx(1, "Cannot have recursive CHOICE");
76    case TEnumerated:
77	*cl  = ASN1_C_UNIV;
78	*ty  = PRIM;
79	*tag = UT_Enumerated;
80	break;
81    case TGeneralString:
82	*cl  = ASN1_C_UNIV;
83	*ty  = PRIM;
84	*tag = UT_GeneralString;
85	break;
86    case TTeletexString:
87	*cl  = ASN1_C_UNIV;
88	*ty  = PRIM;
89	*tag = UT_TeletexString;
90	break;
91    case TGeneralizedTime:
92	*cl  = ASN1_C_UNIV;
93	*ty  = PRIM;
94	*tag = UT_GeneralizedTime;
95	break;
96    case TIA5String:
97	*cl  = ASN1_C_UNIV;
98	*ty  = PRIM;
99	*tag = UT_IA5String;
100	break;
101    case TInteger:
102	*cl  = ASN1_C_UNIV;
103	*ty  = PRIM;
104	*tag = UT_Integer;
105	break;
106    case TNull:
107	*cl  = ASN1_C_UNIV;
108	*ty  = PRIM;
109	*tag = UT_Null;
110	break;
111    case TOID:
112	*cl  = ASN1_C_UNIV;
113	*ty  = PRIM;
114	*tag = UT_OID;
115	break;
116    case TOctetString:
117	*cl  = ASN1_C_UNIV;
118	*ty  = PRIM;
119	*tag = UT_OctetString;
120	break;
121    case TPrintableString:
122	*cl  = ASN1_C_UNIV;
123	*ty  = PRIM;
124	*tag = UT_PrintableString;
125	break;
126    case TSequence:
127    case TSequenceOf:
128	*cl  = ASN1_C_UNIV;
129	*ty  = CONS;
130	*tag = UT_Sequence;
131	break;
132    case TSet:
133    case TSetOf:
134	*cl  = ASN1_C_UNIV;
135	*ty  = CONS;
136	*tag = UT_Set;
137	break;
138    case TTag:
139	*cl  = t->tag.tagclass;
140	*ty  = is_primitive_type(t->subtype->type) ? PRIM : CONS;
141	*tag = t->tag.tagvalue;
142	break;
143    case TType:
144	if ((t->symbol->stype == Stype && t->symbol->type == NULL)
145	    || t->symbol->stype == SUndefined) {
146	    lex_error_message("%s is imported or still undefined, "
147			      " can't generate tag checking data in CHOICE "
148			      "without this information",
149			      t->symbol->name);
150	    exit(1);
151	}
152	find_tag(t->symbol->type, cl, ty, tag);
153	return;
154    case TUTCTime:
155	*cl  = ASN1_C_UNIV;
156	*ty  = PRIM;
157	*tag = UT_UTCTime;
158	break;
159    case TUTF8String:
160	*cl  = ASN1_C_UNIV;
161	*ty  = PRIM;
162	*tag = UT_UTF8String;
163	break;
164    case TBMPString:
165	*cl  = ASN1_C_UNIV;
166	*ty  = PRIM;
167	*tag = UT_BMPString;
168	break;
169    case TUniversalString:
170	*cl  = ASN1_C_UNIV;
171	*ty  = PRIM;
172	*tag = UT_UniversalString;
173	break;
174    case TVisibleString:
175	*cl  = ASN1_C_UNIV;
176	*ty  = PRIM;
177	*tag = UT_VisibleString;
178	break;
179    default:
180	abort();
181    }
182}
183
184static void
185range_check(const char *name,
186	    const char *length,
187	    const char *forwstr,
188	    struct range *r)
189{
190    if (r->min == r->max + 2 || r->min < r->max)
191	fprintf (codefile,
192		 "if ((%s)->%s > %d) {\n"
193		 "e = ASN1_MAX_CONSTRAINT; %s;\n"
194		 "}\n",
195		 name, length, r->max, forwstr);
196    if (r->min - 1 == r->max || r->min < r->max)
197	fprintf (codefile,
198		 "if ((%s)->%s < %d) {\n"
199		 "e = ASN1_MIN_CONSTRAINT; %s;\n"
200		 "}\n",
201		 name, length, r->min, forwstr);
202    if (r->max == r->min)
203	fprintf (codefile,
204		 "if ((%s)->%s != %d) {\n"
205		 "e = ASN1_EXACT_CONSTRAINT; %s;\n"
206		 "}\n",
207		 name, length, r->min, forwstr);
208}
209
210static int
211decode_type (const char *name, const Type *t, int optional,
212	     const char *forwstr, const char *tmpstr, const char *dertype,
213	     unsigned int depth)
214{
215    switch (t->type) {
216    case TType: {
217	if (optional)
218	    fprintf(codefile,
219		    "%s = calloc(1, sizeof(*%s));\n"
220		    "if (%s == NULL) %s;\n",
221		    name, name, name, forwstr);
222	fprintf (codefile,
223		 "e = decode_%s(p, len, %s, &l);\n",
224		 t->symbol->gen_name, name);
225	if (optional) {
226	    fprintf (codefile,
227		     "if(e) {\n"
228		     "free(%s);\n"
229		     "%s = NULL;\n"
230		     "} else {\n"
231		     "p += l; len -= l; ret += l;\n"
232		     "}\n",
233		     name, name);
234	} else {
235	    fprintf (codefile,
236		     "if(e) %s;\n",
237		     forwstr);
238	    fprintf (codefile,
239		     "p += l; len -= l; ret += l;\n");
240	}
241	break;
242    }
243    case TInteger:
244	if(t->members) {
245	    fprintf(codefile,
246		    "{\n"
247		    "int enumint;\n");
248	    decode_primitive ("integer", "&enumint", forwstr);
249	    fprintf(codefile,
250		    "*%s = enumint;\n"
251		    "}\n",
252		    name);
253	} else if (t->range == NULL) {
254	    decode_primitive ("heim_integer", name, forwstr);
255	} else if (t->range->min == INT_MIN && t->range->max == INT_MAX) {
256	    decode_primitive ("integer", name, forwstr);
257	} else if (t->range->min == 0 && t->range->max == UINT_MAX) {
258	    decode_primitive ("unsigned", name, forwstr);
259	} else if (t->range->min == 0 && t->range->max == INT_MAX) {
260	    decode_primitive ("unsigned", name, forwstr);
261	} else
262	    errx(1, "%s: unsupported range %d -> %d",
263		 name, t->range->min, t->range->max);
264	break;
265    case TBoolean:
266      decode_primitive ("boolean", name, forwstr);
267      break;
268    case TEnumerated:
269	decode_primitive ("enumerated", name, forwstr);
270	break;
271    case TOctetString:
272	if (dertype) {
273	    fprintf(codefile,
274		    "if (%s == CONS) {\n",
275		    dertype);
276	    decode_primitive("octet_string_ber", name, forwstr);
277	    fprintf(codefile,
278		    "} else {\n");
279	}
280	decode_primitive ("octet_string", name, forwstr);
281	if (dertype)
282	    fprintf(codefile, "}\n");
283	if (t->range)
284	    range_check(name, "length", forwstr, t->range);
285	break;
286    case TBitString: {
287	Member *m;
288	int pos = 0;
289
290	if (ASN1_TAILQ_EMPTY(t->members)) {
291	    decode_primitive ("bit_string", name, forwstr);
292	    break;
293	}
294	fprintf(codefile,
295		"if (len < 1) return ASN1_OVERRUN;\n"
296		"p++; len--; ret++;\n");
297	fprintf(codefile,
298		"do {\n"
299		"if (len < 1) break;\n");
300	ASN1_TAILQ_FOREACH(m, t->members, members) {
301	    while (m->val / 8 > pos / 8) {
302		fprintf (codefile,
303			 "p++; len--; ret++;\n"
304			 "if (len < 1) break;\n");
305		pos += 8;
306	    }
307	    fprintf (codefile,
308		     "(%s)->%s = (*p >> %d) & 1;\n",
309		     name, m->gen_name, 7 - m->val % 8);
310	}
311	fprintf(codefile,
312		"} while(0);\n");
313	fprintf (codefile,
314		 "p += len; ret += len;\n");
315	break;
316    }
317    case TSequence: {
318	Member *m;
319
320	if (t->members == NULL)
321	    break;
322
323	ASN1_TAILQ_FOREACH(m, t->members, members) {
324	    char *s = NULL;
325
326	    if (m->ellipsis)
327		continue;
328
329	    if (asprintf (&s, "%s(%s)->%s", m->optional ? "" : "&",
330			  name, m->gen_name) < 0 || s == NULL)
331		errx(1, "malloc");
332	    decode_type (s, m->type, m->optional, forwstr, m->gen_name, NULL,
333		depth + 1);
334	    free (s);
335	}
336
337	break;
338    }
339    case TSet: {
340	Member *m;
341	unsigned int memno;
342
343	if(t->members == NULL)
344	    break;
345
346	fprintf(codefile, "{\n");
347	fprintf(codefile, "unsigned int members = 0;\n");
348	fprintf(codefile, "while(len > 0) {\n");
349	fprintf(codefile,
350		"Der_class class;\n"
351		"Der_type type;\n"
352		"int tag;\n"
353		"e = der_get_tag (p, len, &class, &type, &tag, NULL);\n"
354		"if(e) %s;\n", forwstr);
355	fprintf(codefile, "switch (MAKE_TAG(class, type, tag)) {\n");
356	memno = 0;
357	ASN1_TAILQ_FOREACH(m, t->members, members) {
358	    char *s;
359
360	    assert(m->type->type == TTag);
361
362	    fprintf(codefile, "case MAKE_TAG(%s, %s, %s):\n",
363		    classname(m->type->tag.tagclass),
364		    is_primitive_type(m->type->subtype->type) ? "PRIM" : "CONS",
365		    valuename(m->type->tag.tagclass, m->type->tag.tagvalue));
366
367	    if (asprintf (&s, "%s(%s)->%s", m->optional ? "" : "&", name, m->gen_name) < 0 || s == NULL)
368		errx(1, "malloc");
369	    if(m->optional)
370		fprintf(codefile,
371			"%s = calloc(1, sizeof(*%s));\n"
372			"if (%s == NULL) { e = ENOMEM; %s; }\n",
373			s, s, s, forwstr);
374	    decode_type (s, m->type, 0, forwstr, m->gen_name, NULL, depth + 1);
375	    free (s);
376
377	    fprintf(codefile, "members |= (1 << %d);\n", memno);
378	    memno++;
379	    fprintf(codefile, "break;\n");
380	}
381	fprintf(codefile,
382		"default:\n"
383		"return ASN1_MISPLACED_FIELD;\n"
384		"break;\n");
385	fprintf(codefile, "}\n");
386	fprintf(codefile, "}\n");
387	memno = 0;
388	ASN1_TAILQ_FOREACH(m, t->members, members) {
389	    char *s;
390
391	    if (asprintf (&s, "%s->%s", name, m->gen_name) < 0 || s == NULL)
392		errx(1, "malloc");
393	    fprintf(codefile, "if((members & (1 << %d)) == 0)\n", memno);
394	    if(m->optional)
395		fprintf(codefile, "%s = NULL;\n", s);
396	    else if(m->defval)
397		gen_assign_defval(s, m->defval);
398	    else
399		fprintf(codefile, "return ASN1_MISSING_FIELD;\n");
400	    free(s);
401	    memno++;
402	}
403	fprintf(codefile, "}\n");
404	break;
405    }
406    case TSetOf:
407    case TSequenceOf: {
408	char *n = NULL;
409	char *sname = NULL;
410
411	fprintf (codefile,
412		 "{\n"
413		 "size_t %s_origlen = len;\n"
414		 "size_t %s_oldret = ret;\n"
415		 "size_t %s_olen = 0;\n"
416		 "void *%s_tmp;\n"
417		 "ret = 0;\n"
418		 "(%s)->len = 0;\n"
419		 "(%s)->val = NULL;\n",
420		 tmpstr,
421		 tmpstr,
422		 tmpstr,
423		 tmpstr,
424		 name,
425		 name);
426
427	fprintf (codefile,
428		 "while(ret < %s_origlen) {\n"
429		 "size_t %s_nlen = %s_olen + sizeof(*((%s)->val));\n"
430		 "if (%s_olen > %s_nlen) { e = ASN1_OVERFLOW; %s; }\n"
431		 "%s_olen = %s_nlen;\n"
432		 "%s_tmp = realloc((%s)->val, %s_olen);\n"
433		 "if (%s_tmp == NULL) { e = ENOMEM; %s; }\n"
434		 "(%s)->val = %s_tmp;\n",
435		 tmpstr,
436		 tmpstr, tmpstr, name,
437		 tmpstr, tmpstr, forwstr,
438		 tmpstr, tmpstr,
439		 tmpstr, name, tmpstr,
440		 tmpstr, forwstr,
441		 name, tmpstr);
442
443	if (asprintf (&n, "&(%s)->val[(%s)->len]", name, name) < 0 || n == NULL)
444	    errx(1, "malloc");
445	if (asprintf (&sname, "%s_s_of", tmpstr) < 0 || sname == NULL)
446	    errx(1, "malloc");
447	decode_type (n, t->subtype, 0, forwstr, sname, NULL, depth + 1);
448	fprintf (codefile,
449		 "(%s)->len++;\n"
450		 "len = %s_origlen - ret;\n"
451		 "}\n"
452		 "ret += %s_oldret;\n"
453		 "}\n",
454		 name,
455		 tmpstr, tmpstr);
456	if (t->range)
457	    range_check(name, "len", forwstr, t->range);
458	free (n);
459	free (sname);
460	break;
461    }
462    case TGeneralizedTime:
463	decode_primitive ("generalized_time", name, forwstr);
464	break;
465    case TGeneralString:
466	decode_primitive ("general_string", name, forwstr);
467	break;
468    case TTeletexString:
469	decode_primitive ("general_string", name, forwstr);
470	break;
471    case TTag:{
472    	char *tname = NULL, *typestring = NULL;
473	char *ide = NULL;
474
475	if (asprintf(&typestring, "%s_type", tmpstr) < 0 || typestring == NULL)
476	    errx(1, "malloc");
477
478	fprintf(codefile,
479		"{\n"
480		"size_t %s_datalen, %s_oldlen;\n"
481		"Der_type %s;\n",
482		tmpstr, tmpstr, typestring);
483	if(support_ber)
484	    fprintf(codefile,
485		    "int is_indefinite%u;\n", depth);
486
487	fprintf(codefile, "e = der_match_tag_and_length(p, len, %s, &%s, %s, "
488		"&%s_datalen, &l);\n",
489		classname(t->tag.tagclass),
490		typestring,
491		valuename(t->tag.tagclass, t->tag.tagvalue),
492		tmpstr);
493
494	/* XXX hardcode for now */
495	if (support_ber && t->subtype->type == TOctetString) {
496	    ide = typestring;
497	} else {
498	    fprintf(codefile,
499		    "if (e == 0 && %s != %s) { e = ASN1_BAD_ID; }\n",
500		    typestring,
501		    is_primitive_type(t->subtype->type) ? "PRIM" : "CONS");
502	}
503
504	if(optional) {
505	    fprintf(codefile,
506		    "if(e) {\n"
507		    "%s = NULL;\n"
508		    "} else {\n"
509		     "%s = calloc(1, sizeof(*%s));\n"
510		     "if (%s == NULL) { e = ENOMEM; %s; }\n",
511		     name, name, name, name, forwstr);
512	} else {
513	    fprintf(codefile, "if(e) %s;\n", forwstr);
514	}
515	fprintf (codefile,
516		 "p += l; len -= l; ret += l;\n"
517		 "%s_oldlen = len;\n",
518		 tmpstr);
519	if(support_ber)
520	    fprintf (codefile,
521		     "if((is_indefinite%u = _heim_fix_dce(%s_datalen, &len)) < 0)\n"
522		     "{ e = ASN1_BAD_FORMAT; %s; }\n"
523		     "if (is_indefinite%u) { if (len < 2) { e = ASN1_OVERRUN; %s; } len -= 2; }",
524		     depth, tmpstr, forwstr, depth, forwstr);
525	else
526	    fprintf(codefile,
527		    "if (%s_datalen > len) { e = ASN1_OVERRUN; %s; }\n"
528		    "len = %s_datalen;\n", tmpstr, forwstr, tmpstr);
529	if (asprintf (&tname, "%s_Tag", tmpstr) < 0 || tname == NULL)
530	    errx(1, "malloc");
531	decode_type (name, t->subtype, 0, forwstr, tname, ide, depth + 1);
532	if(support_ber)
533	    fprintf(codefile,
534		    "if(is_indefinite%u){\n"
535		    "len += 2;\n"
536		    "e = der_match_tag_and_length(p, len, "
537		    "(Der_class)0, &%s, UT_EndOfContent, "
538		    "&%s_datalen, &l);\n"
539		    "if(e) %s;\n"
540		    "p += l; len -= l; ret += l;\n"
541		    "if (%s != (Der_type)0) { e = ASN1_BAD_ID; %s; }\n"
542		    "} else \n",
543		    depth,
544		    typestring,
545		    tmpstr,
546		    forwstr,
547		    typestring, forwstr);
548	fprintf(codefile,
549		"len = %s_oldlen - %s_datalen;\n",
550		tmpstr, tmpstr);
551	if(optional)
552	    fprintf(codefile,
553		    "}\n");
554	fprintf(codefile,
555		"}\n");
556	free(tname);
557	free(typestring);
558	break;
559    }
560    case TChoice: {
561	Member *m, *have_ellipsis = NULL;
562	const char *els = "";
563
564	if (t->members == NULL)
565	    break;
566
567	ASN1_TAILQ_FOREACH(m, t->members, members) {
568	    const Type *tt = m->type;
569	    char *s = NULL;
570	    Der_class cl;
571	    Der_type  ty;
572	    unsigned  tag;
573
574	    if (m->ellipsis) {
575		have_ellipsis = m;
576		continue;
577	    }
578
579	    find_tag(tt, &cl, &ty, &tag);
580
581	    fprintf(codefile,
582		    "%sif (der_match_tag(p, len, %s, %s, %s, NULL) == 0) {\n",
583		    els,
584		    classname(cl),
585		    ty ? "CONS" : "PRIM",
586		    valuename(cl, tag));
587	    if (asprintf (&s, "%s(%s)->u.%s", m->optional ? "" : "&",
588			  name, m->gen_name) < 0 || s == NULL)
589		errx(1, "malloc");
590	    decode_type (s, m->type, m->optional, forwstr, m->gen_name, NULL,
591		depth + 1);
592	    fprintf(codefile,
593		    "(%s)->element = %s;\n",
594		    name, m->label);
595	    free(s);
596	    fprintf(codefile,
597		    "}\n");
598	    els = "else ";
599	}
600	if (have_ellipsis) {
601	    fprintf(codefile,
602		    "else {\n"
603		    "(%s)->u.%s.data = calloc(1, len);\n"
604		    "if ((%s)->u.%s.data == NULL) {\n"
605		    "e = ENOMEM; %s;\n"
606		    "}\n"
607		    "(%s)->u.%s.length = len;\n"
608		    "memcpy((%s)->u.%s.data, p, len);\n"
609		    "(%s)->element = %s;\n"
610		    "p += len;\n"
611		    "ret += len;\n"
612		    "len = 0;\n"
613		    "}\n",
614		    name, have_ellipsis->gen_name,
615		    name, have_ellipsis->gen_name,
616		    forwstr,
617		    name, have_ellipsis->gen_name,
618		    name, have_ellipsis->gen_name,
619		    name, have_ellipsis->label);
620	} else {
621	    fprintf(codefile,
622		    "else {\n"
623		    "e = ASN1_PARSE_ERROR;\n"
624		    "%s;\n"
625		    "}\n",
626		    forwstr);
627	}
628	break;
629    }
630    case TUTCTime:
631	decode_primitive ("utctime", name, forwstr);
632	break;
633    case TUTF8String:
634	decode_primitive ("utf8string", name, forwstr);
635	break;
636    case TPrintableString:
637	decode_primitive ("printable_string", name, forwstr);
638	break;
639    case TIA5String:
640	decode_primitive ("ia5_string", name, forwstr);
641	break;
642    case TBMPString:
643	decode_primitive ("bmp_string", name, forwstr);
644	break;
645    case TUniversalString:
646	decode_primitive ("universal_string", name, forwstr);
647	break;
648    case TVisibleString:
649	decode_primitive ("visible_string", name, forwstr);
650	break;
651    case TNull:
652	fprintf (codefile, "/* NULL */\n");
653	break;
654    case TOID:
655	decode_primitive ("oid", name, forwstr);
656	break;
657    default :
658	abort ();
659    }
660    return 0;
661}
662
663void
664generate_type_decode (const Symbol *s)
665{
666    int preserve = preserve_type(s->name) ? TRUE : FALSE;
667
668    fprintf (codefile, "int ASN1CALL\n"
669	     "decode_%s(const unsigned char *p HEIMDAL_UNUSED_ATTRIBUTE,"
670	     " size_t len HEIMDAL_UNUSED_ATTRIBUTE, %s *data, size_t *size)\n"
671	     "{\n",
672	     s->gen_name, s->gen_name);
673
674    switch (s->type->type) {
675    case TInteger:
676    case TBoolean:
677    case TOctetString:
678    case TOID:
679    case TGeneralizedTime:
680    case TGeneralString:
681    case TTeletexString:
682    case TUTF8String:
683    case TPrintableString:
684    case TIA5String:
685    case TBMPString:
686    case TUniversalString:
687    case TVisibleString:
688    case TUTCTime:
689    case TNull:
690    case TEnumerated:
691    case TBitString:
692    case TSequence:
693    case TSequenceOf:
694    case TSet:
695    case TSetOf:
696    case TTag:
697    case TType:
698    case TChoice:
699	fprintf (codefile,
700		 "size_t ret = 0;\n"
701		 "size_t l HEIMDAL_UNUSED_ATTRIBUTE;\n"
702		 "int e HEIMDAL_UNUSED_ATTRIBUTE;\n");
703	if (preserve)
704	    fprintf (codefile, "const unsigned char *begin = p;\n");
705
706	fprintf (codefile, "\n");
707	fprintf (codefile, "memset(data, 0, sizeof(*data));\n"); /* hack to avoid `unused variable' */
708
709	decode_type ("data", s->type, 0, "goto fail", "Top", NULL, 1);
710	if (preserve)
711	    fprintf (codefile,
712		     "data->_save.data = calloc(1, ret);\n"
713		     "if (data->_save.data == NULL) { \n"
714		     "e = ENOMEM; goto fail; \n"
715		     "}\n"
716		     "data->_save.length = ret;\n"
717		     "memcpy(data->_save.data, begin, ret);\n");
718	fprintf (codefile,
719		 "if(size) *size = ret;\n"
720		 "return 0;\n");
721	fprintf (codefile,
722		 "fail:\n"
723		 "free_%s(data);\n"
724		 "return e;\n",
725		 s->gen_name);
726	break;
727    default:
728	abort ();
729    }
730    fprintf (codefile, "}\n\n");
731}
732