lib/libcrypto/asn1/tasn_utl.c

   1 /* $OpenBSD: tasn_utl.c,v 1.12 2017/01/29 17:49:22 beck Exp $ */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project 2000.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2000-2004 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 #include <stddef.h>
  60 #include <string.h>
  61 #include <openssl/asn1.h>
  62 #include <openssl/asn1t.h>
  63 #include <openssl/objects.h>
  64 #include <openssl/err.h>
  65
  66 /* Utility functions for manipulating fields and offsets */
  67
  68 /* Add 'offset' to 'addr' */
  69 #define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)
  70
  71 /* Given an ASN1_ITEM CHOICE type return
  72  * the selector value
  73  */
  74
  75 int
  76 asn1_get_choice_selector(ASN1_VALUE **pval, const ASN1_ITEM *it)
  77 {
  78         int *sel = offset2ptr(*pval, it->utype);
  79         return *sel;
  80 }
  81
  82 /* Given an ASN1_ITEM CHOICE type set
  83  * the selector value, return old value.
  84  */
  85
  86 int
  87 asn1_set_choice_selector(ASN1_VALUE **pval, int value, const ASN1_ITEM *it)
  88 {
  89         int *sel, ret;
  90         sel = offset2ptr(*pval, it->utype);
  91         ret = *sel;
  92         *sel = value;
  93         return ret;
  94 }
  95
  96 /* Do reference counting. The value 'op' decides what to do.
  97  * if it is +1 then the count is incremented. If op is 0 count is
  98  * set to 1. If op is -1 count is decremented and the return value
  99  * is the current refrence count or 0 if no reference count exists.
 100  */
 101
 102 int
 103 asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)
 104 {
 105         const ASN1_AUX *aux;
 106         int *lck, ret;
 107
 108         if ((it->itype != ASN1_ITYPE_SEQUENCE) &&
 109             (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))
 110                 return 0;
 111         aux = it->funcs;
 112         if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT))
 113                 return 0;
 114         lck = offset2ptr(*pval, aux->ref_offset);
 115         if (op == 0) {
 116                 *lck = 1;
 117                 return 1;
 118         }
 119         ret = CRYPTO_add(lck, op, aux->ref_lock);
 120         return ret;
 121 }
 122
 123 static ASN1_ENCODING *
 124 asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
 125 {
 126         const ASN1_AUX *aux;
 127
 128         if (!pval || !*pval)
 129                 return NULL;
 130         aux = it->funcs;
 131         if (!aux || !(aux->flags & ASN1_AFLG_ENCODING))
 132                 return NULL;
 133         return offset2ptr(*pval, aux->enc_offset);
 134 }
 135
 136 void
 137 asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
 138 {
 139         ASN1_ENCODING *enc;
 140
 141         enc = asn1_get_enc_ptr(pval, it);
 142         if (enc) {
 143                 enc->enc = NULL;
 144                 enc->len = 0;
 145                 enc->modified = 1;
 146         }
 147 }
 148
 149 void
 150 asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
 151 {
 152         ASN1_ENCODING *enc;
 153
 154         enc = asn1_get_enc_ptr(pval, it);
 155         if (enc) {
 156                 free(enc->enc);
 157                 enc->enc = NULL;
 158                 enc->len = 0;
 159                 enc->modified = 1;
 160         }
 161 }
 162
 163 int
 164 asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
 165     const ASN1_ITEM *it)
 166 {
 167         ASN1_ENCODING *enc;
 168
 169         enc = asn1_get_enc_ptr(pval, it);
 170         if (!enc)
 171                 return 1;
 172
 173         free(enc->enc);
 174         enc->enc = malloc(inlen);
 175         if (!enc->enc)
 176                 return 0;
 177         memcpy(enc->enc, in, inlen);
 178         enc->len = inlen;
 179         enc->modified = 0;
 180
 181         return 1;
 182 }
 183
 184 int
 185 asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,
 186     const ASN1_ITEM *it)
 187 {
 188         ASN1_ENCODING *enc;
 189
 190         enc = asn1_get_enc_ptr(pval, it);
 191         if (!enc || enc->modified)
 192                 return 0;
 193         if (out) {
 194                 memcpy(*out, enc->enc, enc->len);
 195                 *out += enc->len;
 196         }
 197         if (len)
 198                 *len = enc->len;
 199         return 1;
 200 }
 201
 202 /* Given an ASN1_TEMPLATE get a pointer to a field */
 203 ASN1_VALUE **
 204 asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
 205 {
 206         ASN1_VALUE **pvaltmp;
 207
 208         if (tt->flags & ASN1_TFLG_COMBINE)
 209                 return pval;
 210         pvaltmp = offset2ptr(*pval, tt->offset);
 211         /* NOTE for BOOLEAN types the field is just a plain
 212          * int so we can't return int **, so settle for
 213          * (int *).
 214          */
 215         return pvaltmp;
 216 }
 217
 218 /* Handle ANY DEFINED BY template, find the selector, look up
 219  * the relevant ASN1_TEMPLATE in the table and return it.
 220  */
 221
 222 const ASN1_TEMPLATE *
 223 asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt, int nullerr)
 224 {
 225         const ASN1_ADB *adb;
 226         const ASN1_ADB_TABLE *atbl;
 227         long selector;
 228         ASN1_VALUE **sfld;
 229         int i;
 230
 231         if (!(tt->flags & ASN1_TFLG_ADB_MASK))
 232                 return tt;
 233
 234         /* Else ANY DEFINED BY ... get the table */
 235         adb = (const ASN1_ADB *)tt->item;
 236
 237         /* Get the selector field */
 238         sfld = offset2ptr(*pval, adb->offset);
 239
 240         /* Check if NULL */
 241         if (!sfld) {
 242                 if (!adb->null_tt)
 243                         goto err;
 244                 return adb->null_tt;
 245         }
 246
 247         /* Convert type to a long:
 248          * NB: don't check for NID_undef here because it
 249          * might be a legitimate value in the table
 250          */
 251         if (tt->flags & ASN1_TFLG_ADB_OID)
 252                 selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
 253         else
 254                 selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
 255
 256         /* Try to find matching entry in table
 257          * Maybe should check application types first to
 258          * allow application override? Might also be useful
 259          * to have a flag which indicates table is sorted and
 260          * we can do a binary search. For now stick to a
 261          * linear search.
 262          */
 263
 264         for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
 265                 if (atbl->value == selector)
 266                         return &atbl->tt;
 267
 268         /* FIXME: need to search application table too */
 269
 270         /* No match, return default type */
 271         if (!adb->default_tt)
 272                 goto err;
 273         return adb->default_tt;
 274
 275 err:
 276         /* FIXME: should log the value or OID of unsupported type */
 277         if (nullerr)
 278                 ASN1error(ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 279         return NULL;
 280 }