xref: /freebsd/crypto/heimdal/lib/asn1/gen_decode.c (revision 1b7487592987c91020063a311a14dc15b6e58075)
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  
37  RCSID("$Id$");
38  
39  static void
40  decode_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  
59  static void
60  find_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  
184  static void
185  range_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 > %" PRId64 ") {\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 < %" PRId64 ") {\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 != %" PRId64 ") {\n"
205  		 "e = ASN1_EXACT_CONSTRAINT; %s;\n"
206  		 "}\n",
207  		 name, length, r->min, forwstr);
208  }
209  
210  static int
211  decode_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 <= INT64_MAX) {
256  	    decode_primitive ("integer64", name, forwstr);
257  	} else if (t->range->min >= 0 && t->range->max > UINT_MAX) {
258  	    decode_primitive ("unsigned64", name, forwstr);
259  	} else if (t->range->min >= INT_MIN && t->range->max <= INT_MAX) {
260  	    decode_primitive ("integer", name, forwstr);
261  	} else if (t->range->min >= 0 && t->range->max <= UINT_MAX) {
262  	    decode_primitive ("unsigned", name, forwstr);
263  	} else
264  	    errx(1, "%s: unsupported range %" PRId64 " -> %" PRId64,
265  		 name, t->range->min, t->range->max);
266  	break;
267      case TBoolean:
268        decode_primitive ("boolean", name, forwstr);
269        break;
270      case TEnumerated:
271  	decode_primitive ("enumerated", name, forwstr);
272  	break;
273      case TOctetString:
274  	if (dertype) {
275  	    fprintf(codefile,
276  		    "if (%s == CONS) {\n",
277  		    dertype);
278  	    decode_primitive("octet_string_ber", name, forwstr);
279  	    fprintf(codefile,
280  		    "} else {\n");
281  	}
282  	decode_primitive ("octet_string", name, forwstr);
283  	if (dertype)
284  	    fprintf(codefile, "}\n");
285  	if (t->range)
286  	    range_check(name, "length", forwstr, t->range);
287  	break;
288      case TBitString: {
289  	Member *m;
290  	int pos = 0;
291  
292  	if (ASN1_TAILQ_EMPTY(t->members)) {
293  	    decode_primitive ("bit_string", name, forwstr);
294  	    break;
295  	}
296  	fprintf(codefile,
297  		"if (len < 1) return ASN1_OVERRUN;\n"
298  		"p++; len--; ret++;\n");
299  	fprintf(codefile,
300  		"do {\n"
301  		"if (len < 1) break;\n");
302  	ASN1_TAILQ_FOREACH(m, t->members, members) {
303  	    while (m->val / 8 > pos / 8) {
304  		fprintf (codefile,
305  			 "p++; len--; ret++;\n"
306  			 "if (len < 1) break;\n");
307  		pos += 8;
308  	    }
309  	    fprintf (codefile,
310  		     "(%s)->%s = (*p >> %d) & 1;\n",
311  		     name, m->gen_name, 7 - m->val % 8);
312  	}
313  	fprintf(codefile,
314  		"} while(0);\n");
315  	fprintf (codefile,
316  		 "p += len; ret += len;\n");
317  	break;
318      }
319      case TSequence: {
320  	Member *m;
321  
322  	if (t->members == NULL)
323  	    break;
324  
325  	ASN1_TAILQ_FOREACH(m, t->members, members) {
326  	    char *s = NULL;
327  
328  	    if (m->ellipsis)
329  		continue;
330  
331  	    if (asprintf (&s, "%s(%s)->%s", m->optional ? "" : "&",
332  			  name, m->gen_name) < 0 || s == NULL)
333  		errx(1, "malloc");
334  	    decode_type (s, m->type, m->optional, forwstr, m->gen_name, NULL,
335  		depth + 1);
336  	    free (s);
337  	}
338  
339  	break;
340      }
341      case TSet: {
342  	Member *m;
343  	unsigned int memno;
344  
345  	if(t->members == NULL)
346  	    break;
347  
348  	fprintf(codefile, "{\n");
349  	fprintf(codefile, "unsigned int members = 0;\n");
350  	fprintf(codefile, "while(len > 0) {\n");
351  	fprintf(codefile,
352  		"Der_class class;\n"
353  		"Der_type type;\n"
354  		"int tag;\n"
355  		"e = der_get_tag (p, len, &class, &type, &tag, NULL);\n"
356  		"if(e) %s;\n", forwstr);
357  	fprintf(codefile, "switch (MAKE_TAG(class, type, tag)) {\n");
358  	memno = 0;
359  	ASN1_TAILQ_FOREACH(m, t->members, members) {
360  	    char *s;
361  
362  	    assert(m->type->type == TTag);
363  
364  	    fprintf(codefile, "case MAKE_TAG(%s, %s, %s):\n",
365  		    classname(m->type->tag.tagclass),
366  		    is_primitive_type(m->type->subtype->type) ? "PRIM" : "CONS",
367  		    valuename(m->type->tag.tagclass, m->type->tag.tagvalue));
368  
369  	    if (asprintf (&s, "%s(%s)->%s", m->optional ? "" : "&", name, m->gen_name) < 0 || s == NULL)
370  		errx(1, "malloc");
371  	    if(m->optional)
372  		fprintf(codefile,
373  			"%s = calloc(1, sizeof(*%s));\n"
374  			"if (%s == NULL) { e = ENOMEM; %s; }\n",
375  			s, s, s, forwstr);
376  	    decode_type (s, m->type, 0, forwstr, m->gen_name, NULL, depth + 1);
377  	    free (s);
378  
379  	    fprintf(codefile, "members |= (1 << %d);\n", memno);
380  	    memno++;
381  	    fprintf(codefile, "break;\n");
382  	}
383  	fprintf(codefile,
384  		"default:\n"
385  		"return ASN1_MISPLACED_FIELD;\n"
386  		"break;\n");
387  	fprintf(codefile, "}\n");
388  	fprintf(codefile, "}\n");
389  	memno = 0;
390  	ASN1_TAILQ_FOREACH(m, t->members, members) {
391  	    char *s;
392  
393  	    if (asprintf (&s, "%s->%s", name, m->gen_name) < 0 || s == NULL)
394  		errx(1, "malloc");
395  	    fprintf(codefile, "if((members & (1 << %d)) == 0)\n", memno);
396  	    if(m->optional)
397  		fprintf(codefile, "%s = NULL;\n", s);
398  	    else if(m->defval)
399  		gen_assign_defval(s, m->defval);
400  	    else
401  		fprintf(codefile, "return ASN1_MISSING_FIELD;\n");
402  	    free(s);
403  	    memno++;
404  	}
405  	fprintf(codefile, "}\n");
406  	break;
407      }
408      case TSetOf:
409      case TSequenceOf: {
410  	char *n = NULL;
411  	char *sname = NULL;
412  
413  	fprintf (codefile,
414  		 "{\n"
415  		 "size_t %s_origlen = len;\n"
416  		 "size_t %s_oldret = ret;\n"
417  		 "size_t %s_olen = 0;\n"
418  		 "void *%s_tmp;\n"
419  		 "ret = 0;\n"
420  		 "(%s)->len = 0;\n"
421  		 "(%s)->val = NULL;\n",
422  		 tmpstr,
423  		 tmpstr,
424  		 tmpstr,
425  		 tmpstr,
426  		 name,
427  		 name);
428  
429  	fprintf (codefile,
430  		 "while(ret < %s_origlen) {\n"
431  		 "size_t %s_nlen = %s_olen + sizeof(*((%s)->val));\n"
432  		 "if (%s_olen > %s_nlen) { e = ASN1_OVERFLOW; %s; }\n"
433  		 "%s_olen = %s_nlen;\n"
434  		 "%s_tmp = realloc((%s)->val, %s_olen);\n"
435  		 "if (%s_tmp == NULL) { e = ENOMEM; %s; }\n"
436  		 "(%s)->val = %s_tmp;\n",
437  		 tmpstr,
438  		 tmpstr, tmpstr, name,
439  		 tmpstr, tmpstr, forwstr,
440  		 tmpstr, tmpstr,
441  		 tmpstr, name, tmpstr,
442  		 tmpstr, forwstr,
443  		 name, tmpstr);
444  
445  	if (asprintf (&n, "&(%s)->val[(%s)->len]", name, name) < 0 || n == NULL)
446  	    errx(1, "malloc");
447  	if (asprintf (&sname, "%s_s_of", tmpstr) < 0 || sname == NULL)
448  	    errx(1, "malloc");
449  	decode_type (n, t->subtype, 0, forwstr, sname, NULL, depth + 1);
450  	fprintf (codefile,
451  		 "(%s)->len++;\n"
452  		 "len = %s_origlen - ret;\n"
453  		 "}\n"
454  		 "ret += %s_oldret;\n"
455  		 "}\n",
456  		 name,
457  		 tmpstr, tmpstr);
458  	if (t->range)
459  	    range_check(name, "len", forwstr, t->range);
460  	free (n);
461  	free (sname);
462  	break;
463      }
464      case TGeneralizedTime:
465  	decode_primitive ("generalized_time", name, forwstr);
466  	break;
467      case TGeneralString:
468  	decode_primitive ("general_string", name, forwstr);
469  	break;
470      case TTeletexString:
471  	decode_primitive ("general_string", name, forwstr);
472  	break;
473      case TTag:{
474      	char *tname = NULL, *typestring = NULL;
475  	char *ide = NULL;
476  
477  	if (asprintf(&typestring, "%s_type", tmpstr) < 0 || typestring == NULL)
478  	    errx(1, "malloc");
479  
480  	fprintf(codefile,
481  		"{\n"
482  		"size_t %s_datalen, %s_oldlen;\n"
483  		"Der_type %s;\n",
484  		tmpstr, tmpstr, typestring);
485  	if(support_ber)
486  	    fprintf(codefile,
487  		    "int is_indefinite%u;\n", depth);
488  
489  	fprintf(codefile, "e = der_match_tag_and_length(p, len, %s, &%s, %s, "
490  		"&%s_datalen, &l);\n",
491  		classname(t->tag.tagclass),
492  		typestring,
493  		valuename(t->tag.tagclass, t->tag.tagvalue),
494  		tmpstr);
495  
496  	/* XXX hardcode for now */
497  	if (support_ber && t->subtype->type == TOctetString) {
498  	    ide = typestring;
499  	} else {
500  	    fprintf(codefile,
501  		    "if (e == 0 && %s != %s) { e = ASN1_BAD_ID; }\n",
502  		    typestring,
503  		    is_primitive_type(t->subtype->type) ? "PRIM" : "CONS");
504  	}
505  
506  	if(optional) {
507  	    fprintf(codefile,
508  		    "if(e) {\n"
509  		    "%s = NULL;\n"
510  		    "} else {\n"
511  		     "%s = calloc(1, sizeof(*%s));\n"
512  		     "if (%s == NULL) { e = ENOMEM; %s; }\n",
513  		     name, name, name, name, forwstr);
514  	} else {
515  	    fprintf(codefile, "if(e) %s;\n", forwstr);
516  	}
517  	fprintf (codefile,
518  		 "p += l; len -= l; ret += l;\n"
519  		 "%s_oldlen = len;\n",
520  		 tmpstr);
521  	if(support_ber)
522  	    fprintf (codefile,
523  		     "if((is_indefinite%u = _heim_fix_dce(%s_datalen, &len)) < 0)\n"
524  		     "{ e = ASN1_BAD_FORMAT; %s; }\n"
525  		     "if (is_indefinite%u) { if (len < 2) { e = ASN1_OVERRUN; %s; } len -= 2; }",
526  		     depth, tmpstr, forwstr, depth, forwstr);
527  	else
528  	    fprintf(codefile,
529  		    "if (%s_datalen > len) { e = ASN1_OVERRUN; %s; }\n"
530  		    "len = %s_datalen;\n", tmpstr, forwstr, tmpstr);
531  	if (asprintf (&tname, "%s_Tag", tmpstr) < 0 || tname == NULL)
532  	    errx(1, "malloc");
533  	decode_type (name, t->subtype, 0, forwstr, tname, ide, depth + 1);
534  	if(support_ber)
535  	    fprintf(codefile,
536  		    "if(is_indefinite%u){\n"
537  		    "len += 2;\n"
538  		    "e = der_match_tag_and_length(p, len, "
539  		    "(Der_class)0, &%s, UT_EndOfContent, "
540  		    "&%s_datalen, &l);\n"
541  		    "if(e) %s;\n"
542  		    "p += l; len -= l; ret += l;\n"
543  		    "if (%s != (Der_type)0) { e = ASN1_BAD_ID; %s; }\n"
544  		    "} else \n",
545  		    depth,
546  		    typestring,
547  		    tmpstr,
548  		    forwstr,
549  		    typestring, forwstr);
550  	fprintf(codefile,
551  		"len = %s_oldlen - %s_datalen;\n",
552  		tmpstr, tmpstr);
553  	if(optional)
554  	    fprintf(codefile,
555  		    "}\n");
556  	fprintf(codefile,
557  		"}\n");
558  	free(tname);
559  	free(typestring);
560  	break;
561      }
562      case TChoice: {
563  	Member *m, *have_ellipsis = NULL;
564  	const char *els = "";
565  
566  	if (t->members == NULL)
567  	    break;
568  
569  	ASN1_TAILQ_FOREACH(m, t->members, members) {
570  	    const Type *tt = m->type;
571  	    char *s = NULL;
572  	    Der_class cl;
573  	    Der_type  ty;
574  	    unsigned  tag;
575  
576  	    if (m->ellipsis) {
577  		have_ellipsis = m;
578  		continue;
579  	    }
580  
581  	    find_tag(tt, &cl, &ty, &tag);
582  
583  	    fprintf(codefile,
584  		    "%sif (der_match_tag(p, len, %s, %s, %s, NULL) == 0) {\n",
585  		    els,
586  		    classname(cl),
587  		    ty ? "CONS" : "PRIM",
588  		    valuename(cl, tag));
589  	    fprintf(codefile,
590  		    "(%s)->element = %s;\n",
591  		    name, m->label);
592  	    if (asprintf (&s, "%s(%s)->u.%s", m->optional ? "" : "&",
593  			  name, m->gen_name) < 0 || s == NULL)
594  		errx(1, "malloc");
595  	    decode_type (s, m->type, m->optional, forwstr, m->gen_name, NULL,
596  		depth + 1);
597  	    free(s);
598  	    fprintf(codefile,
599  		    "}\n");
600  	    els = "else ";
601  	}
602  	if (have_ellipsis) {
603  	    fprintf(codefile,
604  		    "else {\n"
605  		    "(%s)->element = %s;\n"
606  		    "(%s)->u.%s.data = calloc(1, len);\n"
607  		    "if ((%s)->u.%s.data == NULL) {\n"
608  		    "e = ENOMEM; %s;\n"
609  		    "}\n"
610  		    "(%s)->u.%s.length = len;\n"
611  		    "memcpy((%s)->u.%s.data, p, len);\n"
612  		    "p += len;\n"
613  		    "ret += len;\n"
614  		    "len = 0;\n"
615  		    "}\n",
616  		    name, have_ellipsis->label,
617  		    name, have_ellipsis->gen_name,
618  		    name, have_ellipsis->gen_name,
619  		    forwstr,
620  		    name, have_ellipsis->gen_name,
621  		    name, have_ellipsis->gen_name);
622  	} else {
623  	    fprintf(codefile,
624  		    "else {\n"
625  		    "e = ASN1_PARSE_ERROR;\n"
626  		    "%s;\n"
627  		    "}\n",
628  		    forwstr);
629  	}
630  	break;
631      }
632      case TUTCTime:
633  	decode_primitive ("utctime", name, forwstr);
634  	break;
635      case TUTF8String:
636  	decode_primitive ("utf8string", name, forwstr);
637  	break;
638      case TPrintableString:
639  	decode_primitive ("printable_string", name, forwstr);
640  	break;
641      case TIA5String:
642  	decode_primitive ("ia5_string", name, forwstr);
643  	break;
644      case TBMPString:
645  	decode_primitive ("bmp_string", name, forwstr);
646  	break;
647      case TUniversalString:
648  	decode_primitive ("universal_string", name, forwstr);
649  	break;
650      case TVisibleString:
651  	decode_primitive ("visible_string", name, forwstr);
652  	break;
653      case TNull:
654  	fprintf (codefile, "/* NULL */\n");
655  	break;
656      case TOID:
657  	decode_primitive ("oid", name, forwstr);
658  	break;
659      default :
660  	abort ();
661      }
662      return 0;
663  }
664  
665  void
666  generate_type_decode (const Symbol *s)
667  {
668      int preserve = preserve_type(s->name) ? TRUE : FALSE;
669  
670      fprintf (codefile, "int ASN1CALL\n"
671  	     "decode_%s(const unsigned char *p HEIMDAL_UNUSED_ATTRIBUTE,"
672  	     " size_t len HEIMDAL_UNUSED_ATTRIBUTE, %s *data, size_t *size)\n"
673  	     "{\n",
674  	     s->gen_name, s->gen_name);
675  
676      switch (s->type->type) {
677      case TInteger:
678      case TBoolean:
679      case TOctetString:
680      case TOID:
681      case TGeneralizedTime:
682      case TGeneralString:
683      case TTeletexString:
684      case TUTF8String:
685      case TPrintableString:
686      case TIA5String:
687      case TBMPString:
688      case TUniversalString:
689      case TVisibleString:
690      case TUTCTime:
691      case TNull:
692      case TEnumerated:
693      case TBitString:
694      case TSequence:
695      case TSequenceOf:
696      case TSet:
697      case TSetOf:
698      case TTag:
699      case TType:
700      case TChoice:
701  	fprintf (codefile,
702  		 "size_t ret = 0;\n"
703  		 "size_t l HEIMDAL_UNUSED_ATTRIBUTE;\n"
704  		 "int e HEIMDAL_UNUSED_ATTRIBUTE;\n");
705  	if (preserve)
706  	    fprintf (codefile, "const unsigned char *begin = p;\n");
707  
708  	fprintf (codefile, "\n");
709  	fprintf (codefile, "memset(data, 0, sizeof(*data));\n"); /* hack to avoid `unused variable' */
710  
711  	decode_type ("data", s->type, 0, "goto fail", "Top", NULL, 1);
712  	if (preserve)
713  	    fprintf (codefile,
714  		     "data->_save.data = calloc(1, ret);\n"
715  		     "if (data->_save.data == NULL) { \n"
716  		     "e = ENOMEM; goto fail; \n"
717  		     "}\n"
718  		     "data->_save.length = ret;\n"
719  		     "memcpy(data->_save.data, begin, ret);\n");
720  	fprintf (codefile,
721  		 "if(size) *size = ret;\n"
722  		 "return 0;\n");
723  	fprintf (codefile,
724  		 "fail:\n"
725  		 "free_%s(data);\n"
726  		 "return e;\n",
727  		 s->gen_name);
728  	break;
729      default:
730  	abort ();
731      }
732      fprintf (codefile, "}\n\n");
733  }
734