xref: /freebsd/crypto/heimdal/lib/asn1/gen_decode.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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 1.18 2002/08/09 15:37:34 joda 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 TEnumerated:
77 	decode_primitive ("enumerated", name);
78 	break;
79     case TOctetString:
80 	decode_primitive ("octet_string", name);
81 	break;
82     case TOID :
83 	decode_primitive ("oid", name);
84 	break;
85     case TBitString: {
86 	Member *m;
87 	int tag = -1;
88 	int pos;
89 
90 	fprintf (codefile,
91 		 "e = der_match_tag_and_length (p, len, UNIV, PRIM, UT_BitString,"
92 		 "&reallen, &l);\n"
93 		 "FORW;\n"
94 		 "if(len < reallen)\n"
95 		 "return ASN1_OVERRUN;\n"
96 		 "p++;\n"
97 		 "len--;\n"
98 		 "reallen--;\n"
99 		 "ret++;\n");
100 	pos = 0;
101 	for (m = t->members; m && tag != m->val; m = m->next) {
102 	    while (m->val / 8 > pos / 8) {
103 		fprintf (codefile,
104 			 "p++; len--; reallen--; ret++;\n");
105 		pos += 8;
106 	    }
107 	    fprintf (codefile,
108 		     "%s->%s = (*p >> %d) & 1;\n",
109 		     name, m->gen_name, 7 - m->val % 8);
110 	    if (tag == -1)
111 		tag = m->val;
112 	}
113 	fprintf (codefile,
114 		 "p += reallen; len -= reallen; ret += reallen;\n");
115 	break;
116     }
117     case TSequence: {
118 	Member *m;
119 	int tag = -1;
120 
121 	if (t->members == NULL)
122 	    break;
123 
124 	fprintf (codefile,
125 		 "e = der_match_tag_and_length (p, len, UNIV, CONS, UT_Sequence,"
126 		 "&reallen, &l);\n"
127 		 "FORW;\n"
128 		 "{\n"
129 		 "int dce_fix;\n"
130 		 "if((dce_fix = fix_dce(reallen, &len)) < 0)\n"
131 		 "return ASN1_BAD_FORMAT;\n");
132 
133 	for (m = t->members; m && tag != m->val; m = m->next) {
134 	    char *s;
135 
136 	    asprintf (&s, "%s(%s)->%s", m->optional ? "" : "&", name, m->gen_name);
137 	    if (0 && m->type->type == TType){
138 		if(m->optional)
139 		    fprintf (codefile,
140 			     "%s = malloc(sizeof(*%s));\n"
141 			     "if(%s == NULL) return ENOMEM;\n", s, s, s);
142 		fprintf (codefile,
143 			 "e = decode_seq_%s(p, len, %d, %d, %s, &l);\n",
144 			 m->type->symbol->gen_name,
145 			 m->val,
146 			 m->optional,
147 			 s);
148 		if(m->optional)
149 		    fprintf (codefile,
150 			     "if (e == ASN1_MISSING_FIELD) {\n"
151 			     "free(%s);\n"
152 			     "%s = NULL;\n"
153 			     "e = l = 0;\n"
154 			     "}\n",
155 			     s, s);
156 
157 		fprintf (codefile, "FORW;\n");
158 
159 	    }else{
160 		fprintf (codefile, "{\n"
161 			 "size_t newlen, oldlen;\n\n"
162 			 "e = der_match_tag (p, len, CONTEXT, CONS, %d, &l);\n",
163 			 m->val);
164 		fprintf (codefile,
165 			 "if (e)\n");
166 		if(m->optional)
167 		    /* XXX should look at e */
168 		    fprintf (codefile,
169 			     "%s = NULL;\n", s);
170 		else
171 		    fprintf (codefile,
172 			     "return e;\n");
173 		fprintf (codefile,
174 			 "else {\n");
175 		fprintf (codefile,
176 			 "p += l;\n"
177 			 "len -= l;\n"
178 			 "ret += l;\n"
179 			 "e = der_get_length (p, len, &newlen, &l);\n"
180 			 "FORW;\n"
181 			 "{\n"
182 
183 			 "int dce_fix;\n"
184 			 "oldlen = len;\n"
185 			 "if((dce_fix = fix_dce(newlen, &len)) < 0)"
186 			 "return ASN1_BAD_FORMAT;\n");
187 		if (m->optional)
188 		    fprintf (codefile,
189 			     "%s = malloc(sizeof(*%s));\n"
190 			     "if(%s == NULL) return ENOMEM;\n", s, s, s);
191 		decode_type (s, m->type);
192 		fprintf (codefile,
193 			 "if(dce_fix){\n"
194 			 "e = der_match_tag_and_length (p, len, "
195 			 "(Der_class)0, (Der_type)0, 0, &reallen, &l);\n"
196 			 "FORW;\n"
197 			 "}else \n"
198 			 "len = oldlen - newlen;\n"
199 			 "}\n"
200 			 "}\n");
201 		fprintf (codefile,
202 			 "}\n");
203 	    }
204 	    if (tag == -1)
205 		tag = m->val;
206 	    free (s);
207 	}
208 	fprintf(codefile,
209 		"if(dce_fix){\n"
210 		"e = der_match_tag_and_length (p, len, "
211 		"(Der_class)0, (Der_type)0, 0, &reallen, &l);\n"
212 		"FORW;\n"
213 		"}\n"
214 		"}\n");
215 
216 	break;
217     }
218     case TSequenceOf: {
219 	char *n;
220 
221 	fprintf (codefile,
222 		 "e = der_match_tag_and_length (p, len, UNIV, CONS, UT_Sequence,"
223 		 "&reallen, &l);\n"
224 		 "FORW;\n"
225 		 "if(len < reallen)\n"
226 		 "return ASN1_OVERRUN;\n"
227 		 "len = reallen;\n");
228 
229 	fprintf (codefile,
230 		 "{\n"
231 		 "size_t origlen = len;\n"
232 		 "int oldret = ret;\n"
233 		 "ret = 0;\n"
234 		 "(%s)->len = 0;\n"
235 		 "(%s)->val = NULL;\n"
236 		 "while(ret < origlen) {\n"
237 		 "(%s)->len++;\n"
238 		 "(%s)->val = realloc((%s)->val, sizeof(*((%s)->val)) * (%s)->len);\n",
239 		 name, name, name, name, name, name, name);
240 	asprintf (&n, "&(%s)->val[(%s)->len-1]", name, name);
241 	decode_type (n, t->subtype);
242 	fprintf (codefile,
243 		 "len = origlen - ret;\n"
244 		 "}\n"
245 		 "ret += oldret;\n"
246 		 "}\n");
247 	free (n);
248 	break;
249     }
250     case TGeneralizedTime:
251 	decode_primitive ("generalized_time", name);
252 	break;
253     case TGeneralString:
254 	decode_primitive ("general_string", name);
255 	break;
256     case TApplication:
257 	fprintf (codefile,
258 		 "e = der_match_tag_and_length (p, len, APPL, CONS, %d, "
259 		 "&reallen, &l);\n"
260 		 "FORW;\n"
261 		 "{\n"
262 		 "int dce_fix;\n"
263 		 "if((dce_fix = fix_dce(reallen, &len)) < 0)\n"
264 		 "return ASN1_BAD_FORMAT;\n",
265 		 t->application);
266 	decode_type (name, t->subtype);
267 	fprintf(codefile,
268 		"if(dce_fix){\n"
269 		"e = der_match_tag_and_length (p, len, "
270 		"(Der_class)0, (Der_type)0, 0, &reallen, &l);\n"
271 		"FORW;\n"
272 		"}\n"
273 		"}\n");
274 
275 	break;
276     default :
277 	abort ();
278     }
279 }
280 
281 void
282 generate_type_decode (const Symbol *s)
283 {
284   fprintf (headerfile,
285 	   "int    "
286 	   "decode_%s(const unsigned char *, size_t, %s *, size_t *);\n",
287 	   s->gen_name, s->gen_name);
288 
289   fprintf (codefile, "#define FORW "
290 	   "if(e) goto fail; "
291 	   "p += l; "
292 	   "len -= l; "
293 	   "ret += l\n\n");
294 
295 
296   fprintf (codefile, "int\n"
297 	   "decode_%s(const unsigned char *p,"
298 	   " size_t len, %s *data, size_t *size)\n"
299 	   "{\n",
300 	   s->gen_name, s->gen_name);
301 
302   switch (s->type->type) {
303   case TInteger:
304   case TUInteger:
305   case TOctetString:
306   case TOID:
307   case TGeneralizedTime:
308   case TGeneralString:
309   case TBitString:
310   case TSequence:
311   case TSequenceOf:
312   case TApplication:
313   case TType:
314     fprintf (codefile,
315 	     "size_t ret = 0, reallen;\n"
316 	     "size_t l;\n"
317 	     "int e;\n\n");
318     fprintf (codefile, "memset(data, 0, sizeof(*data));\n");
319     fprintf (codefile, "reallen = 0;\n"); /* hack to avoid `unused variable' */
320 
321     decode_type ("data", s->type);
322     fprintf (codefile,
323 	     "if(size) *size = ret;\n"
324 	     "return 0;\n");
325     fprintf (codefile,
326 	     "fail:\n"
327 	     "free_%s(data);\n"
328 	     "return e;\n",
329 	     s->gen_name);
330     break;
331   default:
332     abort ();
333   }
334   fprintf (codefile, "}\n\n");
335 }
336 
337 void
338 generate_seq_type_decode (const Symbol *s)
339 {
340     fprintf (headerfile,
341 	     "int decode_seq_%s(const unsigned char *, size_t, int, int, "
342 	     "%s *, size_t *);\n",
343 	     s->gen_name, s->gen_name);
344 
345     fprintf (codefile, "int\n"
346 	     "decode_seq_%s(const unsigned char *p, size_t len, int tag, "
347 	     "int optional, %s *data, size_t *size)\n"
348 	     "{\n",
349 	     s->gen_name, s->gen_name);
350 
351     fprintf (codefile,
352 	     "size_t newlen, oldlen;\n"
353 	     "size_t l, ret = 0;\n"
354 	     "int e;\n"
355 	     "int dce_fix;\n");
356 
357     fprintf (codefile,
358 	     "e = der_match_tag(p, len, CONTEXT, CONS, tag, &l);\n"
359 	     "if (e)\n"
360 	     "return e;\n");
361     fprintf (codefile,
362 	     "p += l;\n"
363 	     "len -= l;\n"
364 	     "ret += l;\n"
365 	     "e = der_get_length(p, len, &newlen, &l);\n"
366 	     "if (e)\n"
367 	     "return e;\n"
368 	     "p += l;\n"
369 	     "len -= l;\n"
370 	     "ret += l;\n"
371 	     "oldlen = len;\n"
372 	     "if ((dce_fix = fix_dce(newlen, &len)) < 0)\n"
373 	     "return ASN1_BAD_FORMAT;\n"
374 	     "e = decode_%s(p, len, data, &l);\n"
375 	     "if (e)\n"
376 	     "return e;\n"
377 	     "p += l;\n"
378 	     "len -= l;\n"
379 	     "ret += l;\n"
380 	     "if (dce_fix) {\n"
381 	     "size_t reallen;\n\n"
382 	     "e = der_match_tag_and_length(p, len, "
383 	     "(Der_class)0, (Der_type)0, 0, &reallen, &l);\n"
384 	     "if (e)\n"
385 	     "return e;\n"
386 	     "ret += l;\n"
387 	     "}\n",
388 	     s->gen_name);
389     fprintf (codefile,
390 	     "if(size) *size = ret;\n"
391 	     "return 0;\n");
392 
393     fprintf (codefile, "}\n\n");
394 }
395