xref: /freebsd/crypto/heimdal/lib/asn1/gen_decode.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
1 /*
2  * Copyright (c) 1997 - 2001 Kungliga Tekniska H�gskolan
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 
36 RCSID("$Id: gen_decode.c,v 1.16 2001/02/10 18:14:38 assar Exp $");
37 
38 static void
39 decode_primitive (const char *typename, const char *name)
40 {
41     fprintf (codefile,
42 	     "e = decode_%s(p, len, %s, &l);\n"
43 	     "FORW;\n",
44 	     typename,
45 	     name);
46 }
47 
48 static void
49 decode_type (const char *name, const Type *t)
50 {
51     switch (t->type) {
52     case TType:
53 #if 0
54 	decode_type (name, t->symbol->type);
55 #endif
56 	fprintf (codefile,
57 		 "e = decode_%s(p, len, %s, &l);\n"
58 		 "FORW;\n",
59 		 t->symbol->gen_name, name);
60 	break;
61     case TInteger:
62 	if(t->members == NULL)
63 	    decode_primitive ("integer", name);
64 	else {
65 	    char *s;
66 	    asprintf(&s, "(int*)%s", name);
67 	    if(s == NULL)
68 		errx (1, "out of memory");
69 	    decode_primitive ("integer", s);
70 	    free(s);
71 	}
72 	break;
73     case TUInteger:
74 	decode_primitive ("unsigned", name);
75 	break;
76     case TOctetString:
77 	decode_primitive ("octet_string", name);
78 	break;
79     case TBitString: {
80 	Member *m;
81 	int tag = -1;
82 	int pos;
83 
84 	fprintf (codefile,
85 		 "e = der_match_tag_and_length (p, len, UNIV, PRIM, UT_BitString,"
86 		 "&reallen, &l);\n"
87 		 "FORW;\n"
88 		 "if(len < reallen)\n"
89 		 "return ASN1_OVERRUN;\n"
90 		 "p++;\n"
91 		 "len--;\n"
92 		 "reallen--;\n"
93 		 "ret++;\n");
94 	pos = 0;
95 	for (m = t->members; m && tag != m->val; m = m->next) {
96 	    while (m->val / 8 > pos / 8) {
97 		fprintf (codefile,
98 			 "p++; len--; reallen--; ret++;\n");
99 		pos += 8;
100 	    }
101 	    fprintf (codefile,
102 		     "%s->%s = (*p >> %d) & 1;\n",
103 		     name, m->gen_name, 7 - m->val % 8);
104 	    if (tag == -1)
105 		tag = m->val;
106 	}
107 	fprintf (codefile,
108 		 "p += reallen; len -= reallen; ret += reallen;\n");
109 	break;
110     }
111     case TSequence: {
112 	Member *m;
113 	int tag = -1;
114 
115 	if (t->members == NULL)
116 	    break;
117 
118 	fprintf (codefile,
119 		 "e = der_match_tag_and_length (p, len, UNIV, CONS, UT_Sequence,"
120 		 "&reallen, &l);\n"
121 		 "FORW;\n"
122 		 "{\n"
123 		 "int dce_fix;\n"
124 		 "if((dce_fix = fix_dce(reallen, &len)) < 0)\n"
125 		 "return ASN1_BAD_FORMAT;\n");
126 
127 	for (m = t->members; m && tag != m->val; m = m->next) {
128 	    char *s;
129 
130 	    asprintf (&s, "%s(%s)->%s", m->optional ? "" : "&", name, m->gen_name);
131 	    if (0 && m->type->type == TType){
132 		if(m->optional)
133 		    fprintf (codefile,
134 			     "%s = malloc(sizeof(*%s));\n"
135 			     "if(%s == NULL) return ENOMEM;\n", s, s, s);
136 		fprintf (codefile,
137 			 "e = decode_seq_%s(p, len, %d, %d, %s, &l);\n",
138 			 m->type->symbol->gen_name,
139 			 m->val,
140 			 m->optional,
141 			 s);
142 		if(m->optional)
143 		    fprintf (codefile,
144 			     "if (e == ASN1_MISSING_FIELD) {\n"
145 			     "free(%s);\n"
146 			     "%s = NULL;\n"
147 			     "e = l = 0;\n"
148 			     "}\n",
149 			     s, s);
150 
151 		fprintf (codefile, "FORW;\n");
152 
153 	    }else{
154 		fprintf (codefile, "{\n"
155 			 "size_t newlen, oldlen;\n\n"
156 			 "e = der_match_tag (p, len, CONTEXT, CONS, %d, &l);\n",
157 			 m->val);
158 		fprintf (codefile,
159 			 "if (e)\n");
160 		if(m->optional)
161 		    /* XXX should look at e */
162 		    fprintf (codefile,
163 			     "%s = NULL;\n", s);
164 		else
165 		    fprintf (codefile,
166 			     "return e;\n");
167 		fprintf (codefile,
168 			 "else {\n");
169 		fprintf (codefile,
170 			 "p += l;\n"
171 			 "len -= l;\n"
172 			 "ret += l;\n"
173 			 "e = der_get_length (p, len, &newlen, &l);\n"
174 			 "FORW;\n"
175 			 "{\n"
176 
177 			 "int dce_fix;\n"
178 			 "oldlen = len;\n"
179 			 "if((dce_fix = fix_dce(newlen, &len)) < 0)"
180 			 "return ASN1_BAD_FORMAT;\n");
181 		if (m->optional)
182 		    fprintf (codefile,
183 			     "%s = malloc(sizeof(*%s));\n"
184 			     "if(%s == NULL) return ENOMEM;\n", s, s, s);
185 		decode_type (s, m->type);
186 		fprintf (codefile,
187 			 "if(dce_fix){\n"
188 			 "e = der_match_tag_and_length (p, len, "
189 			 "(Der_class)0, (Der_type)0, 0, &reallen, &l);\n"
190 			 "FORW;\n"
191 			 "}else \n"
192 			 "len = oldlen - newlen;\n"
193 			 "}\n"
194 			 "}\n");
195 		fprintf (codefile,
196 			 "}\n");
197 	    }
198 	    if (tag == -1)
199 		tag = m->val;
200 	    free (s);
201 	}
202 	fprintf(codefile,
203 		"if(dce_fix){\n"
204 		"e = der_match_tag_and_length (p, len, "
205 		"(Der_class)0, (Der_type)0, 0, &reallen, &l);\n"
206 		"FORW;\n"
207 		"}\n"
208 		"}\n");
209 
210 	break;
211     }
212     case TSequenceOf: {
213 	char *n;
214 
215 	fprintf (codefile,
216 		 "e = der_match_tag_and_length (p, len, UNIV, CONS, UT_Sequence,"
217 		 "&reallen, &l);\n"
218 		 "FORW;\n"
219 		 "if(len < reallen)\n"
220 		 "return ASN1_OVERRUN;\n"
221 		 "len = reallen;\n");
222 
223 	fprintf (codefile,
224 		 "{\n"
225 		 "size_t origlen = len;\n"
226 		 "int oldret = ret;\n"
227 		 "ret = 0;\n"
228 		 "(%s)->len = 0;\n"
229 		 "(%s)->val = NULL;\n"
230 		 "while(ret < origlen) {\n"
231 		 "(%s)->len++;\n"
232 		 "(%s)->val = realloc((%s)->val, sizeof(*((%s)->val)) * (%s)->len);\n",
233 		 name, name, name, name, name, name, name);
234 	asprintf (&n, "&(%s)->val[(%s)->len-1]", name, name);
235 	decode_type (n, t->subtype);
236 	fprintf (codefile,
237 		 "len = origlen - ret;\n"
238 		 "}\n"
239 		 "ret += oldret;\n"
240 		 "}\n");
241 	free (n);
242 	break;
243     }
244     case TGeneralizedTime:
245 	decode_primitive ("generalized_time", name);
246 	break;
247     case TGeneralString:
248 	decode_primitive ("general_string", name);
249 	break;
250     case TApplication:
251 	fprintf (codefile,
252 		 "e = der_match_tag_and_length (p, len, APPL, CONS, %d, "
253 		 "&reallen, &l);\n"
254 		 "FORW;\n"
255 		 "{\n"
256 		 "int dce_fix;\n"
257 		 "if((dce_fix = fix_dce(reallen, &len)) < 0)\n"
258 		 "return ASN1_BAD_FORMAT;\n",
259 		 t->application);
260 	decode_type (name, t->subtype);
261 	fprintf(codefile,
262 		"if(dce_fix){\n"
263 		"e = der_match_tag_and_length (p, len, "
264 		"(Der_class)0, (Der_type)0, 0, &reallen, &l);\n"
265 		"FORW;\n"
266 		"}\n"
267 		"}\n");
268 
269 	break;
270     default :
271 	abort ();
272     }
273 }
274 
275 void
276 generate_type_decode (const Symbol *s)
277 {
278   fprintf (headerfile,
279 	   "int    "
280 	   "decode_%s(const unsigned char *, size_t, %s *, size_t *);\n",
281 	   s->gen_name, s->gen_name);
282 
283   fprintf (codefile, "#define FORW "
284 	   "if(e) goto fail; "
285 	   "p += l; "
286 	   "len -= l; "
287 	   "ret += l\n\n");
288 
289 
290   fprintf (codefile, "int\n"
291 	   "decode_%s(const unsigned char *p,"
292 	   " size_t len, %s *data, size_t *size)\n"
293 	   "{\n",
294 	   s->gen_name, s->gen_name);
295 
296   switch (s->type->type) {
297   case TInteger:
298   case TUInteger:
299   case TOctetString:
300   case TGeneralizedTime:
301   case TGeneralString:
302   case TBitString:
303   case TSequence:
304   case TSequenceOf:
305   case TApplication:
306   case TType:
307     fprintf (codefile,
308 	     "size_t ret = 0, reallen;\n"
309 	     "size_t l;\n"
310 	     "int i, e;\n\n");
311     fprintf (codefile, "memset(data, 0, sizeof(*data));\n");
312     fprintf (codefile, "i = 0;\n"); /* hack to avoid `unused variable' */
313     fprintf (codefile, "reallen = 0;\n"); /* hack to avoid `unused variable' */
314 
315     decode_type ("data", s->type);
316     fprintf (codefile,
317 	     "if(size) *size = ret;\n"
318 	     "return 0;\n");
319     fprintf (codefile,
320 	     "fail:\n"
321 	     "free_%s(data);\n"
322 	     "return e;\n",
323 	     s->gen_name);
324     break;
325   default:
326     abort ();
327   }
328   fprintf (codefile, "}\n\n");
329 }
330 
331 void
332 generate_seq_type_decode (const Symbol *s)
333 {
334     fprintf (headerfile,
335 	     "int decode_seq_%s(const unsigned char *, size_t, int, int, "
336 	     "%s *, size_t *);\n",
337 	     s->gen_name, s->gen_name);
338 
339     fprintf (codefile, "int\n"
340 	     "decode_seq_%s(const unsigned char *p, size_t len, int tag, "
341 	     "int optional, %s *data, size_t *size)\n"
342 	     "{\n",
343 	     s->gen_name, s->gen_name);
344 
345     fprintf (codefile,
346 	     "size_t newlen, oldlen;\n"
347 	     "size_t l, ret = 0;\n"
348 	     "int e;\n"
349 	     "int dce_fix;\n");
350 
351     fprintf (codefile,
352 	     "e = der_match_tag(p, len, CONTEXT, CONS, tag, &l);\n"
353 	     "if (e)\n"
354 	     "return e;\n");
355     fprintf (codefile,
356 	     "p += l;\n"
357 	     "len -= l;\n"
358 	     "ret += l;\n"
359 	     "e = der_get_length(p, len, &newlen, &l);\n"
360 	     "if (e)\n"
361 	     "return e;\n"
362 	     "p += l;\n"
363 	     "len -= l;\n"
364 	     "ret += l;\n"
365 	     "oldlen = len;\n"
366 	     "if ((dce_fix = fix_dce(newlen, &len)) < 0)\n"
367 	     "return ASN1_BAD_FORMAT;\n"
368 	     "e = decode_%s(p, len, data, &l);\n"
369 	     "if (e)\n"
370 	     "return e;\n"
371 	     "p += l;\n"
372 	     "len -= l;\n"
373 	     "ret += l;\n"
374 	     "if (dce_fix) {\n"
375 	     "size_t reallen;\n\n"
376 	     "e = der_match_tag_and_length(p, len, "
377 	     "(Der_class)0, (Der_type)0, 0, &reallen, &l);\n"
378 	     "if (e)\n"
379 	     "return e;\n"
380 	     "ret += l;\n"
381 	     "}\n",
382 	     s->gen_name);
383     fprintf (codefile,
384 	     "if(size) *size = ret;\n"
385 	     "return 0;\n");
386 
387     fprintf (codefile, "}\n\n");
388 }
389