crypto/heimdal-0.6.3/lib/asn1/der_get.c

   1 /*
   2  * Copyright (c) 1997 - 2002 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 "der_locl.h"
  35
  36 RCSID("$Id: der_get.c,v 1.33 2002/09/03 16:21:49 nectar Exp $");
  37
  38 #include <version.h>
  39
  40 /*
  41  * All decoding functions take a pointer `p' to first position in
  42  * which to read, from the left, `len' which means the maximum number
  43  * of characters we are able to read, `ret' were the value will be
  44  * returned and `size' where the number of used bytes is stored.
  45  * Either 0 or an error code is returned.
  46  */
  47
  48 static int
  49 der_get_unsigned (const unsigned char *p, size_t len,
  50                   unsigned *ret, size_t *size)
  51 {
  52     unsigned val = 0;
  53     size_t oldlen = len;
  54
  55     while (len--)
  56         val = val * 256 + *p++;
  57     *ret = val;
  58     if(size) *size = oldlen;
  59     return 0;
  60 }
  61
  62 int
  63 der_get_int (const unsigned char *p, size_t len,
  64              int *ret, size_t *size)
  65 {
  66     int val = 0;
  67     size_t oldlen = len;
  68
  69     if (len > 0) {
  70         val = (signed char)*p++;
  71         while (--len)
  72             val = val * 256 + *p++;
  73     }
  74     *ret = val;
  75     if(size) *size = oldlen;
  76     return 0;
  77 }
  78
  79 int
  80 der_get_length (const unsigned char *p, size_t len,
  81                 size_t *val, size_t *size)
  82 {
  83     size_t v;
  84
  85     if (len <= 0)
  86         return ASN1_OVERRUN;
  87     --len;
  88     v = *p++;
  89     if (v < 128) {
  90         *val = v;
  91         if(size) *size = 1;
  92     } else {
  93         int e;
  94         size_t l;
  95         unsigned tmp;
  96
  97         if(v == 0x80){
  98             *val = ASN1_INDEFINITE;
  99             if(size) *size = 1;
 100             return 0;
 101         }
 102         v &= 0x7F;
 103         if (len < v)
 104             return ASN1_OVERRUN;
 105         e = der_get_unsigned (p, v, &tmp, &l);
 106         if(e) return e;
 107         *val = tmp;
 108         if(size) *size = l + 1;
 109     }
 110     return 0;
 111 }
 112
 113 int
 114 der_get_general_string (const unsigned char *p, size_t len,
 115                         general_string *str, size_t *size)
 116 {
 117     char *s;
 118
 119     s = malloc (len + 1);
 120     if (s == NULL)
 121         return ENOMEM;
 122     memcpy (s, p, len);
 123     s[len] = '\0';
 124     *str = s;
 125     if(size) *size = len;
 126     return 0;
 127 }
 128
 129 int
 130 der_get_octet_string (const unsigned char *p, size_t len,
 131                       octet_string *data, size_t *size)
 132 {
 133     data->length = len;
 134     data->data = malloc(len);
 135     if (data->data == NULL && data->length != 0)
 136         return ENOMEM;
 137     memcpy (data->data, p, len);
 138     if(size) *size = len;
 139     return 0;
 140 }
 141
 142 int
 143 der_get_oid (const unsigned char *p, size_t len,
 144              oid *data, size_t *size)
 145 {
 146     int n;
 147     size_t oldlen = len;
 148
 149     if (len < 1)
 150         return ASN1_OVERRUN;
 151
 152     data->components = malloc(len * sizeof(*data->components));
 153     if (data->components == NULL && len != 0)
 154         return ENOMEM;
 155     data->components[0] = (*p) / 40;
 156     data->components[1] = (*p) % 40;
 157     --len;
 158     ++p;
 159     for (n = 2; len > 0; ++n) {
 160         unsigned u = 0;
 161
 162         do {
 163             --len;
 164             u = u * 128 + (*p++ % 128);
 165         } while (len > 0 && p[-1] & 0x80);
 166         data->components[n] = u;
 167     }
 168     if (p[-1] & 0x80) {
 169         free_oid (data);
 170         return ASN1_OVERRUN;
 171     }
 172     data->length = n;
 173     if (size)
 174         *size = oldlen;
 175     return 0;
 176 }
 177
 178 int
 179 der_get_tag (const unsigned char *p, size_t len,
 180              Der_class *class, Der_type *type,
 181              int *tag, size_t *size)
 182 {
 183     if (len < 1)
 184         return ASN1_OVERRUN;
 185     *class = (Der_class)(((*p) >> 6) & 0x03);
 186     *type = (Der_type)(((*p) >> 5) & 0x01);
 187     *tag = (*p) & 0x1F;
 188     if(size) *size = 1;
 189     return 0;
 190 }
 191
 192 int
 193 der_match_tag (const unsigned char *p, size_t len,
 194                Der_class class, Der_type type,
 195                int tag, size_t *size)
 196 {
 197     size_t l;
 198     Der_class thisclass;
 199     Der_type thistype;
 200     int thistag;
 201     int e;
 202
 203     e = der_get_tag (p, len, &thisclass, &thistype, &thistag, &l);
 204     if (e) return e;
 205     if (class != thisclass || type != thistype)
 206         return ASN1_BAD_ID;
 207     if(tag > thistag)
 208         return ASN1_MISPLACED_FIELD;
 209     if(tag < thistag)
 210         return ASN1_MISSING_FIELD;
 211     if(size) *size = l;
 212     return 0;
 213 }
 214
 215 int
 216 der_match_tag_and_length (const unsigned char *p, size_t len,
 217                           Der_class class, Der_type type, int tag,
 218                           size_t *length_ret, size_t *size)
 219 {
 220     size_t l, ret = 0;
 221     int e;
 222
 223     e = der_match_tag (p, len, class, type, tag, &l);
 224     if (e) return e;
 225     p += l;
 226     len -= l;
 227     ret += l;
 228     e = der_get_length (p, len, length_ret, &l);
 229     if (e) return e;
 230     p += l;
 231     len -= l;
 232     ret += l;
 233     if(size) *size = ret;
 234     return 0;
 235 }
 236
 237 int
 238 decode_integer (const unsigned char *p, size_t len,
 239                 int *num, size_t *size)
 240 {
 241     size_t ret = 0;
 242     size_t l, reallen;
 243     int e;
 244
 245     e = der_match_tag (p, len, UNIV, PRIM, UT_Integer, &l);
 246     if (e) return e;
 247     p += l;
 248     len -= l;
 249     ret += l;
 250     e = der_get_length (p, len, &reallen, &l);
 251     if (e) return e;
 252     p += l;
 253     len -= l;
 254     ret += l;
 255     if (reallen > len)
 256         return ASN1_OVERRUN;
 257     e = der_get_int (p, reallen, num, &l);
 258     if (e) return e;
 259     p += l;
 260     len -= l;
 261     ret += l;
 262     if(size) *size = ret;
 263     return 0;
 264 }
 265
 266 int
 267 decode_unsigned (const unsigned char *p, size_t len,
 268                  unsigned *num, size_t *size)
 269 {
 270     size_t ret = 0;
 271     size_t l, reallen;
 272     int e;
 273
 274     e = der_match_tag (p, len, UNIV, PRIM, UT_Integer, &l);
 275     if (e) return e;
 276     p += l;
 277     len -= l;
 278     ret += l;
 279     e = der_get_length (p, len, &reallen, &l);
 280     if (e) return e;
 281     p += l;
 282     len -= l;
 283     ret += l;
 284     if (reallen > len)
 285         return ASN1_OVERRUN;
 286     e = der_get_unsigned (p, reallen, num, &l);
 287     if (e) return e;
 288     p += l;
 289     len -= l;
 290     ret += l;
 291     if(size) *size = ret;
 292     return 0;
 293 }
 294
 295 int
 296 decode_enumerated (const unsigned char *p, size_t len,
 297                    unsigned *num, size_t *size)
 298 {
 299     size_t ret = 0;
 300     size_t l, reallen;
 301     int e;
 302
 303     e = der_match_tag (p, len, UNIV, PRIM, UT_Enumerated, &l);
 304     if (e) return e;
 305     p += l;
 306     len -= l;
 307     ret += l;
 308     e = der_get_length (p, len, &reallen, &l);
 309     if (e) return e;
 310     p += l;
 311     len -= l;
 312     ret += l;
 313     e = der_get_int (p, reallen, num, &l);
 314     if (e) return e;
 315     p += l;
 316     len -= l;
 317     ret += l;
 318     if(size) *size = ret;
 319     return 0;
 320 }
 321
 322 int
 323 decode_general_string (const unsigned char *p, size_t len,
 324                        general_string *str, size_t *size)
 325 {
 326     size_t ret = 0;
 327     size_t l;
 328     int e;
 329     size_t slen;
 330
 331     e = der_match_tag (p, len, UNIV, PRIM, UT_GeneralString, &l);
 332     if (e) return e;
 333     p += l;
 334     len -= l;
 335     ret += l;
 336
 337     e = der_get_length (p, len, &slen, &l);
 338     if (e) return e;
 339     p += l;
 340     len -= l;
 341     ret += l;
 342     if (len < slen)
 343         return ASN1_OVERRUN;
 344
 345     e = der_get_general_string (p, slen, str, &l);
 346     if (e) return e;
 347     p += l;
 348     len -= l;
 349     ret += l;
 350     if(size) *size = ret;
 351     return 0;
 352 }
 353
 354 int
 355 decode_octet_string (const unsigned char *p, size_t len,
 356                      octet_string *k, size_t *size)
 357 {
 358     size_t ret = 0;
 359     size_t l;
 360     int e;
 361     size_t slen;
 362
 363     e = der_match_tag (p, len, UNIV, PRIM, UT_OctetString, &l);
 364     if (e) return e;
 365     p += l;
 366     len -= l;
 367     ret += l;
 368
 369     e = der_get_length (p, len, &slen, &l);
 370     if (e) return e;
 371     p += l;
 372     len -= l;
 373     ret += l;
 374     if (len < slen)
 375         return ASN1_OVERRUN;
 376
 377     e = der_get_octet_string (p, slen, k, &l);
 378     if (e) return e;
 379     p += l;
 380     len -= l;
 381     ret += l;
 382     if(size) *size = ret;
 383     return 0;
 384 }
 385
 386 int
 387 decode_oid (const unsigned char *p, size_t len,
 388             oid *k, size_t *size)
 389 {
 390     size_t ret = 0;
 391     size_t l;
 392     int e;
 393     size_t slen;
 394
 395     e = der_match_tag (p, len, UNIV, PRIM, UT_OID, &l);
 396     if (e) return e;
 397     p += l;
 398     len -= l;
 399     ret += l;
 400
 401     e = der_get_length (p, len, &slen, &l);
 402     if (e) return e;
 403     p += l;
 404     len -= l;
 405     ret += l;
 406     if (len < slen)
 407         return ASN1_OVERRUN;
 408
 409     e = der_get_oid (p, slen, k, &l);
 410     if (e) return e;
 411     p += l;
 412     len -= l;
 413     ret += l;
 414     if(size) *size = ret;
 415     return 0;
 416 }
 417
 418 static void
 419 generalizedtime2time (const char *s, time_t *t)
 420 {
 421     struct tm tm;
 422
 423     memset(&tm, 0, sizeof(tm));
 424     sscanf (s, "%04d%02d%02d%02d%02d%02dZ",
 425             &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &tm.tm_hour,
 426             &tm.tm_min, &tm.tm_sec);
 427     tm.tm_year -= 1900;
 428     tm.tm_mon -= 1;
 429     *t = timegm (&tm);
 430 }
 431
 432 int
 433 decode_generalized_time (const unsigned char *p, size_t len,
 434                          time_t *t, size_t *size)
 435 {
 436     octet_string k;
 437     char *times;
 438     size_t ret = 0;
 439     size_t l;
 440     int e;
 441     size_t slen;
 442
 443     e = der_match_tag (p, len, UNIV, PRIM, UT_GeneralizedTime, &l);
 444     if (e) return e;
 445     p += l;
 446     len -= l;
 447     ret += l;
 448
 449     e = der_get_length (p, len, &slen, &l);
 450     if (e) return e;
 451     p += l;
 452     len -= l;
 453     ret += l;
 454     if (len < slen)
 455         return ASN1_OVERRUN;
 456     e = der_get_octet_string (p, slen, &k, &l);
 457     if (e) return e;
 458     p += l;
 459     len -= l;
 460     ret += l;
 461     times = realloc(k.data, k.length + 1);
 462     if (times == NULL){
 463         free(k.data);
 464         return ENOMEM;
 465     }
 466     times[k.length] = 0;
 467     generalizedtime2time (times, t);
 468     free (times);
 469     if(size) *size = ret;
 470     return 0;
 471 }
 472
 473
 474 int
 475 fix_dce(size_t reallen, size_t *len)
 476 {
 477     if(reallen == ASN1_INDEFINITE)
 478         return 1;
 479     if(*len < reallen)
 480         return -1;
 481     *len = reallen;
 482     return 0;
 483 }