crypto/openssl-0.9.7d/crypto/asn1/tasn_enc.c

   1 /* tasn_enc.c */
   2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
   3  * project 2000.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59
  60 #include <stddef.h>
  61 #include <string.h>
  62 #include <openssl/asn1.h>
  63 #include <openssl/asn1t.h>
  64 #include <openssl/objects.h>
  65
  66 static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass);
  67 static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *seq, unsigned char **out, int skcontlen, const ASN1_ITEM *item, int isset);
  68
  69 /* Encode an ASN1 item, this is compatible with the
  70  * standard 'i2d' function. 'out' points to
  71  * a buffer to output the data to, in future we will
  72  * have more advanced versions that can output data
  73  * a piece at a time and this will simply be a special
  74  * case.
  75  *
  76  * The new i2d has one additional feature. If the output
  77  * buffer is NULL (i.e. *out == NULL) then a buffer is
  78  * allocated and populated with the encoding.
  79  */
  80
  81
  82 int ASN1_item_i2d(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it)
  83 {
  84         if(out && !*out) {
  85                 unsigned char *p, *buf;
  86                 int len;
  87                 len = ASN1_item_ex_i2d(&val, NULL, it, -1, 0);
  88                 if(len <= 0) return len;
  89                 buf = OPENSSL_malloc(len);
  90                 if(!buf) return -1;
  91                 p = buf;
  92                 ASN1_item_ex_i2d(&val, &p, it, -1, 0);
  93                 *out = buf;
  94                 return len;
  95         }
  96
  97         return ASN1_item_ex_i2d(&val, out, it, -1, 0);
  98 }
  99
 100 /* Encode an item, taking care of IMPLICIT tagging (if any).
 101  * This function performs the normal item handling: it can be
 102  * used in external types.
 103  */
 104
 105 int ASN1_item_ex_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass)
 106 {
 107         const ASN1_TEMPLATE *tt = NULL;
 108         unsigned char *p = NULL;
 109         int i, seqcontlen, seqlen;
 110         ASN1_STRING *strtmp;
 111         const ASN1_COMPAT_FUNCS *cf;
 112         const ASN1_EXTERN_FUNCS *ef;
 113         const ASN1_AUX *aux = it->funcs;
 114         ASN1_aux_cb *asn1_cb;
 115         if((it->itype != ASN1_ITYPE_PRIMITIVE) && !*pval) return 0;
 116         if(aux && aux->asn1_cb) asn1_cb = aux->asn1_cb;
 117         else asn1_cb = 0;
 118
 119         switch(it->itype) {
 120
 121                 case ASN1_ITYPE_PRIMITIVE:
 122                 if(it->templates)
 123                         return ASN1_template_i2d(pval, out, it->templates);
 124                 return asn1_i2d_ex_primitive(pval, out, it, tag, aclass);
 125                 break;
 126
 127                 case ASN1_ITYPE_MSTRING:
 128                 strtmp = (ASN1_STRING *)*pval;
 129                 return asn1_i2d_ex_primitive(pval, out, it, -1, 0);
 130
 131                 case ASN1_ITYPE_CHOICE:
 132                 if(asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it))
 133                                 return 0;
 134                 i = asn1_get_choice_selector(pval, it);
 135                 if((i >= 0) && (i < it->tcount)) {
 136                         ASN1_VALUE **pchval;
 137                         const ASN1_TEMPLATE *chtt;
 138                         chtt = it->templates + i;
 139                         pchval = asn1_get_field_ptr(pval, chtt);
 140                         return ASN1_template_i2d(pchval, out, chtt);
 141                 }
 142                 /* Fixme: error condition if selector out of range */
 143                 if(asn1_cb && !asn1_cb(ASN1_OP_I2D_POST, pval, it))
 144                                 return 0;
 145                 break;
 146
 147                 case ASN1_ITYPE_EXTERN:
 148                 /* If new style i2d it does all the work */
 149                 ef = it->funcs;
 150                 return ef->asn1_ex_i2d(pval, out, it, tag, aclass);
 151
 152                 case ASN1_ITYPE_COMPAT:
 153                 /* old style hackery... */
 154                 cf = it->funcs;
 155                 if(out) p = *out;
 156                 i = cf->asn1_i2d(*pval, out);
 157                 /* Fixup for IMPLICIT tag: note this messes up for tags > 30,
 158                  * but so did the old code. Tags > 30 are very rare anyway.
 159                  */
 160                 if(out && (tag != -1))
 161                         *p = aclass | tag | (*p & V_ASN1_CONSTRUCTED);
 162                 return i;
 163
 164                 case ASN1_ITYPE_SEQUENCE:
 165                 i = asn1_enc_restore(&seqcontlen, out, pval, it);
 166                 /* An error occurred */
 167                 if(i < 0) return 0;
 168                 /* We have a valid cached encoding... */
 169                 if(i > 0) return seqcontlen;
 170                 /* Otherwise carry on */
 171                 seqcontlen = 0;
 172                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 173                 if(tag == -1) {
 174                         tag = V_ASN1_SEQUENCE;
 175                         aclass = V_ASN1_UNIVERSAL;
 176                 }
 177                 if(asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it))
 178                                 return 0;
 179                 /* First work out sequence content length */
 180                 for(i = 0, tt = it->templates; i < it->tcount; tt++, i++) {
 181                         const ASN1_TEMPLATE *seqtt;
 182                         ASN1_VALUE **pseqval;
 183                         seqtt = asn1_do_adb(pval, tt, 1);
 184                         if(!seqtt) return 0;
 185                         pseqval = asn1_get_field_ptr(pval, seqtt);
 186                         /* FIXME: check for errors in enhanced version */
 187                         /* FIXME: special handling of indefinite length encoding */
 188                         seqcontlen += ASN1_template_i2d(pseqval, NULL, seqtt);
 189                 }
 190                 seqlen = ASN1_object_size(1, seqcontlen, tag);
 191                 if(!out) return seqlen;
 192                 /* Output SEQUENCE header */
 193                 ASN1_put_object(out, 1, seqcontlen, tag, aclass);
 194                 for(i = 0, tt = it->templates; i < it->tcount; tt++, i++) {
 195                         const ASN1_TEMPLATE *seqtt;
 196                         ASN1_VALUE **pseqval;
 197                         seqtt = asn1_do_adb(pval, tt, 1);
 198                         if(!seqtt) return 0;
 199                         pseqval = asn1_get_field_ptr(pval, seqtt);
 200                         /* FIXME: check for errors in enhanced version */
 201                         ASN1_template_i2d(pseqval, out, seqtt);
 202                 }
 203                 if(asn1_cb  && !asn1_cb(ASN1_OP_I2D_POST, pval, it))
 204                                 return 0;
 205                 return seqlen;
 206
 207                 default:
 208                 return 0;
 209         }
 210         return 0;
 211 }
 212
 213 int ASN1_template_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_TEMPLATE *tt)
 214 {
 215         int i, ret, flags, aclass;
 216         flags = tt->flags;
 217         aclass = flags & ASN1_TFLG_TAG_CLASS;
 218         if(flags & ASN1_TFLG_SK_MASK) {
 219                 /* SET OF, SEQUENCE OF */
 220                 STACK_OF(ASN1_VALUE) *sk = (STACK_OF(ASN1_VALUE) *)*pval;
 221                 int isset, sktag, skaclass;
 222                 int skcontlen, sklen;
 223                 ASN1_VALUE *skitem;
 224                 if(!*pval) return 0;
 225                 if(flags & ASN1_TFLG_SET_OF) {
 226                         isset = 1;
 227                         /* 2 means we reorder */
 228                         if(flags & ASN1_TFLG_SEQUENCE_OF) isset = 2;
 229                 } else isset = 0;
 230                 /* First work out inner tag value */
 231                 if(flags & ASN1_TFLG_IMPTAG) {
 232                         sktag = tt->tag;
 233                         skaclass = aclass;
 234                 } else {
 235                         skaclass = V_ASN1_UNIVERSAL;
 236                         if(isset) sktag = V_ASN1_SET;
 237                         else sktag = V_ASN1_SEQUENCE;
 238                 }
 239                 /* Now work out length of items */
 240                 skcontlen = 0;
 241                 for(i = 0; i < sk_ASN1_VALUE_num(sk); i++) {
 242                         skitem = sk_ASN1_VALUE_value(sk, i);
 243                         skcontlen += ASN1_item_ex_i2d(&skitem, NULL, ASN1_ITEM_ptr(tt->item), -1, 0);
 244                 }
 245                 sklen = ASN1_object_size(1, skcontlen, sktag);
 246                 /* If EXPLICIT need length of surrounding tag */
 247                 if(flags & ASN1_TFLG_EXPTAG)
 248                         ret = ASN1_object_size(1, sklen, tt->tag);
 249                 else ret = sklen;
 250
 251                 if(!out) return ret;
 252
 253                 /* Now encode this lot... */
 254                 /* EXPLICIT tag */
 255                 if(flags & ASN1_TFLG_EXPTAG)
 256                         ASN1_put_object(out, 1, sklen, tt->tag, aclass);
 257                 /* SET or SEQUENCE and IMPLICIT tag */
 258                 ASN1_put_object(out, 1, skcontlen, sktag, skaclass);
 259                 /* And finally the stuff itself */
 260                 asn1_set_seq_out(sk, out, skcontlen, ASN1_ITEM_ptr(tt->item), isset);
 261
 262                 return ret;
 263         }
 264
 265         if(flags & ASN1_TFLG_EXPTAG) {
 266                 /* EXPLICIT tagging */
 267                 /* Find length of tagged item */
 268                 i = ASN1_item_ex_i2d(pval, NULL, ASN1_ITEM_ptr(tt->item), -1, 0);
 269                 if(!i) return 0;
 270                 /* Find length of EXPLICIT tag */
 271                 ret = ASN1_object_size(1, i, tt->tag);
 272                 if(out) {
 273                         /* Output tag and item */
 274                         ASN1_put_object(out, 1, i, tt->tag, aclass);
 275                         ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), -1, 0);
 276                 }
 277                 return ret;
 278         }
 279         if(flags & ASN1_TFLG_IMPTAG) {
 280                 /* IMPLICIT tagging */
 281                 return ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), tt->tag, aclass);
 282         }
 283         /* Nothing special: treat as normal */
 284         return ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), -1, 0);
 285 }
 286
 287 /* Temporary structure used to hold DER encoding of items for SET OF */
 288
 289 typedef struct {
 290         unsigned char *data;
 291         int length;
 292         ASN1_VALUE *field;
 293 } DER_ENC;
 294
 295 static int der_cmp(const void *a, const void *b)
 296 {
 297         const DER_ENC *d1 = a, *d2 = b;
 298         int cmplen, i;
 299         cmplen = (d1->length < d2->length) ? d1->length : d2->length;
 300         i = memcmp(d1->data, d2->data, cmplen);
 301         if(i) return i;
 302         return d1->length - d2->length;
 303 }
 304
 305 /* Output the content octets of SET OF or SEQUENCE OF */
 306
 307 static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *sk, unsigned char **out, int skcontlen, const ASN1_ITEM *item, int do_sort)
 308 {
 309         int i;
 310         ASN1_VALUE *skitem;
 311         unsigned char *tmpdat = NULL, *p = NULL;
 312         DER_ENC *derlst = NULL, *tder;
 313         if(do_sort) {
 314                 /* Don't need to sort less than 2 items */
 315                 if(sk_ASN1_VALUE_num(sk) < 2) do_sort = 0;
 316                 else {
 317                         derlst = OPENSSL_malloc(sk_ASN1_VALUE_num(sk) * sizeof(*derlst));
 318                         tmpdat = OPENSSL_malloc(skcontlen);
 319                         if(!derlst || !tmpdat) return 0;
 320                 }
 321         }
 322         /* If not sorting just output each item */
 323         if(!do_sort) {
 324                 for(i = 0; i < sk_ASN1_VALUE_num(sk); i++) {
 325                         skitem = sk_ASN1_VALUE_value(sk, i);
 326                         ASN1_item_i2d(skitem, out, item);
 327                 }
 328                 return 1;
 329         }
 330         p = tmpdat;
 331         /* Doing sort: build up a list of each member's DER encoding */
 332         for(i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++) {
 333                 skitem = sk_ASN1_VALUE_value(sk, i);
 334                 tder->data = p;
 335                 tder->length = ASN1_item_i2d(skitem, &p, item);
 336                 tder->field = skitem;
 337         }
 338         /* Now sort them */
 339         qsort(derlst, sk_ASN1_VALUE_num(sk), sizeof(*derlst), der_cmp);
 340         /* Output sorted DER encoding */
 341         p = *out;
 342         for(i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++) {
 343                 memcpy(p, tder->data, tder->length);
 344                 p += tder->length;
 345         }
 346         *out = p;
 347         /* If do_sort is 2 then reorder the STACK */
 348         if(do_sort == 2) {
 349                 for(i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++)
 350                         sk_ASN1_VALUE_set(sk, i, tder->field);
 351         }
 352         OPENSSL_free(derlst);
 353         OPENSSL_free(tmpdat);
 354         return 1;
 355 }
 356
 357 static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass)
 358 {
 359         int len;
 360         int utype;
 361         int usetag;
 362
 363         utype = it->utype;
 364
 365         /* Get length of content octets and maybe find
 366          * out the underlying type.
 367          */
 368
 369         len = asn1_ex_i2c(pval, NULL, &utype, it);
 370
 371         /* If SEQUENCE, SET or OTHER then header is
 372          * included in pseudo content octets so don't
 373          * include tag+length. We need to check here
 374          * because the call to asn1_ex_i2c() could change
 375          * utype.
 376          */
 377         if((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) ||
 378            (utype == V_ASN1_OTHER))
 379                 usetag = 0;
 380         else usetag = 1;
 381
 382         /* -1 means omit type */
 383
 384         if(len == -1) return 0;
 385
 386         /* If not implicitly tagged get tag from underlying type */
 387         if(tag == -1) tag = utype;
 388
 389         /* Output tag+length followed by content octets */
 390         if(out) {
 391                 if(usetag) ASN1_put_object(out, 0, len, tag, aclass);
 392                 asn1_ex_i2c(pval, *out, &utype, it);
 393                 *out += len;
 394         }
 395
 396         if(usetag) return ASN1_object_size(0, len, tag);
 397         return len;
 398 }
 399
 400 /* Produce content octets from a structure */
 401
 402 int asn1_ex_i2c(ASN1_VALUE **pval, unsigned char *cout, int *putype, const ASN1_ITEM *it)
 403 {
 404         ASN1_BOOLEAN *tbool = NULL;
 405         ASN1_STRING *strtmp;
 406         ASN1_OBJECT *otmp;
 407         int utype;
 408         unsigned char *cont, c;
 409         int len;
 410         const ASN1_PRIMITIVE_FUNCS *pf;
 411         pf = it->funcs;
 412         if(pf && pf->prim_i2c) return pf->prim_i2c(pval, cout, putype, it);
 413
 414         /* Should type be omitted? */
 415         if((it->itype != ASN1_ITYPE_PRIMITIVE) || (it->utype != V_ASN1_BOOLEAN)) {
 416                 if(!*pval) return -1;
 417         }
 418
 419         if(it->itype == ASN1_ITYPE_MSTRING) {
 420                 /* If MSTRING type set the underlying type */
 421                 strtmp = (ASN1_STRING *)*pval;
 422                 utype = strtmp->type;
 423                 *putype = utype;
 424         } else if(it->utype == V_ASN1_ANY) {
 425                 /* If ANY set type and pointer to value */
 426                 ASN1_TYPE *typ;
 427                 typ = (ASN1_TYPE *)*pval;
 428                 utype = typ->type;
 429                 *putype = utype;
 430                 pval = (ASN1_VALUE **)&typ->value.ptr;
 431         } else utype = *putype;
 432
 433         switch(utype) {
 434                 case V_ASN1_OBJECT:
 435                 otmp = (ASN1_OBJECT *)*pval;
 436                 cont = otmp->data;
 437                 len = otmp->length;
 438                 break;
 439
 440                 case V_ASN1_NULL:
 441                 cont = NULL;
 442                 len = 0;
 443                 break;
 444
 445                 case V_ASN1_BOOLEAN:
 446                 tbool = (ASN1_BOOLEAN *)pval;
 447                 if(*tbool == -1) return -1;
 448                 /* Default handling if value == size field then omit */
 449                 if(*tbool && (it->size > 0)) return -1;
 450                 if(!*tbool && !it->size) return -1;
 451                 c = (unsigned char)*tbool;
 452                 cont = &c;
 453                 len = 1;
 454                 break;
 455
 456                 case V_ASN1_BIT_STRING:
 457                 return i2c_ASN1_BIT_STRING((ASN1_BIT_STRING *)*pval, cout ? &cout : NULL);
 458                 break;
 459
 460                 case V_ASN1_INTEGER:
 461                 case V_ASN1_NEG_INTEGER:
 462                 case V_ASN1_ENUMERATED:
 463                 case V_ASN1_NEG_ENUMERATED:
 464                 /* These are all have the same content format
 465                  * as ASN1_INTEGER
 466                  */
 467                 return i2c_ASN1_INTEGER((ASN1_INTEGER *)*pval, cout ? &cout : NULL);
 468                 break;
 469
 470                 case V_ASN1_OCTET_STRING:
 471                 case V_ASN1_NUMERICSTRING:
 472                 case V_ASN1_PRINTABLESTRING:
 473                 case V_ASN1_T61STRING:
 474                 case V_ASN1_VIDEOTEXSTRING:
 475                 case V_ASN1_IA5STRING:
 476                 case V_ASN1_UTCTIME:
 477                 case V_ASN1_GENERALIZEDTIME:
 478                 case V_ASN1_GRAPHICSTRING:
 479                 case V_ASN1_VISIBLESTRING:
 480                 case V_ASN1_GENERALSTRING:
 481                 case V_ASN1_UNIVERSALSTRING:
 482                 case V_ASN1_BMPSTRING:
 483                 case V_ASN1_UTF8STRING:
 484                 case V_ASN1_SEQUENCE:
 485                 case V_ASN1_SET:
 486                 default:
 487                 /* All based on ASN1_STRING and handled the same */
 488                 strtmp = (ASN1_STRING *)*pval;
 489                 cont = strtmp->data;
 490                 len = strtmp->length;
 491
 492                 break;
 493
 494         }
 495         if(cout && len) memcpy(cout, cont, len);
 496         return len;
 497 }