1 /* tasn_utl.c */
   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 
  60 #include <stddef.h>
  61 #include <string.h>
  62 #include <openssl/asn1.h>
  63 #include <openssl/asn1t.h>
  64 #include <openssl/objects.h>
  65 #include <openssl/err.h>
  66 
  67 /* Utility functions for manipulating fields and offsets */
  68 
  69 /* Add 'offset' to 'addr' */
  70 #define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)
  71 
  72 /* Given an ASN1_ITEM CHOICE type return
  73  * the selector value
  74  */
  75 
  76 int 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 asn1_set_choice_selector(ASN1_VALUE **pval, int value, const ASN1_ITEM *it)
  87         {       
  88         int *sel, ret;
  89         sel = offset2ptr(*pval, it->utype);
  90         ret = *sel;
  91         *sel = value;
  92         return ret;
  93         }
  94 
  95 /* Do reference counting. The value 'op' decides what to do. 
  96  * if it is +1 then the count is incremented. If op is 0 count is
  97  * set to 1. If op is -1 count is decremented and the return value
  98  * is the current refrence count or 0 if no reference count exists.
  99  */
 100 
 101 int asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)
 102         {
 103         const ASN1_AUX *aux;
 104         int *lck, ret;
 105         if ((it->itype != ASN1_ITYPE_SEQUENCE)
 106            && (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))
 107                 return 0;
 108         aux = it->funcs;
 109         if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT))
 110                 return 0;
 111         lck = offset2ptr(*pval, aux->ref_offset);
 112         if (op == 0)
 113                 {
 114                 *lck = 1;
 115                 return 1;
 116                 }
 117         ret = CRYPTO_add(lck, op, aux->ref_lock);
 118 #ifdef REF_PRINT
 119         fprintf(stderr, "%s: Reference Count: %d\n", it->sname, *lck);
 120 #endif
 121 #ifdef REF_CHECK
 122         if (ret < 0) 
 123                 fprintf(stderr, "%s, bad reference count\n", it->sname);
 124 #endif
 125         return ret;
 126         }
 127 
 128 static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
 129         {
 130         const ASN1_AUX *aux;
 131         if (!pval || !*pval)
 132                 return NULL;
 133         aux = it->funcs;
 134         if (!aux || !(aux->flags & ASN1_AFLG_ENCODING))
 135                 return NULL;
 136         return offset2ptr(*pval, aux->enc_offset);
 137         }
 138 
 139 void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
 140         {
 141         ASN1_ENCODING *enc;
 142         enc = asn1_get_enc_ptr(pval, it);
 143         if (enc)
 144                 {
 145                 enc->enc = NULL;
 146                 enc->len = 0;
 147                 enc->modified = 1;
 148                 }
 149         }
 150 
 151 void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
 152         {
 153         ASN1_ENCODING *enc;
 154         enc = asn1_get_enc_ptr(pval, it);
 155         if (enc)
 156                 {
 157                 if (enc->enc)
 158                         OPENSSL_free(enc->enc);
 159                 enc->enc = NULL;
 160                 enc->len = 0;
 161                 enc->modified = 1;
 162                 }
 163         }
 164 
 165 int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
 166                                                          const ASN1_ITEM *it)
 167         {
 168         ASN1_ENCODING *enc;
 169         enc = asn1_get_enc_ptr(pval, it);
 170         if (!enc)
 171                 return 1;
 172 
 173         if (enc->enc)
 174                 OPENSSL_free(enc->enc);
 175         enc->enc = OPENSSL_malloc(inlen);
 176         if (!enc->enc)
 177                 return 0;
 178         memcpy(enc->enc, in, inlen);
 179         enc->len = inlen;
 180         enc->modified = 0;
 181 
 182         return 1;
 183         }
 184                 
 185 int asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,
 186                                                         const ASN1_ITEM *it)
 187         {
 188         ASN1_ENCODING *enc;
 189         enc = asn1_get_enc_ptr(pval, it);
 190         if (!enc || enc->modified)
 191                 return 0;
 192         if (out)
 193                 {
 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 ** asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
 204         {
 205         ASN1_VALUE **pvaltmp;
 206         if (tt->flags & ASN1_TFLG_COMBINE)
 207                 return pval;
 208         pvaltmp = offset2ptr(*pval, tt->offset);
 209         /* NOTE for BOOLEAN types the field is just a plain
 210          * int so we can't return int **, so settle for
 211          * (int *).
 212          */
 213         return pvaltmp;
 214         }
 215 
 216 /* Handle ANY DEFINED BY template, find the selector, look up
 217  * the relevant ASN1_TEMPLATE in the table and return it.
 218  */
 219 
 220 const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt,
 221                                                                 int nullerr)
 222         {
 223         const ASN1_ADB *adb;
 224         const ASN1_ADB_TABLE *atbl;
 225         long selector;
 226         ASN1_VALUE **sfld;
 227         int i;
 228         if (!(tt->flags & ASN1_TFLG_ADB_MASK))
 229                 return tt;
 230 
 231         /* Else ANY DEFINED BY ... get the table */
 232         adb = ASN1_ADB_ptr(tt->item);
 233 
 234         /* Get the selector field */
 235         sfld = offset2ptr(*pval, adb->offset);
 236 
 237         /* Check if NULL */
 238         if (!sfld)
 239                 {
 240                 if (!adb->null_tt)
 241                         goto err;
 242                 return adb->null_tt;
 243                 }
 244 
 245         /* Convert type to a long:
 246          * NB: don't check for NID_undef here because it
 247          * might be a legitimate value in the table
 248          */
 249         if (tt->flags & ASN1_TFLG_ADB_OID) 
 250                 selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
 251         else 
 252                 selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
 253 
 254         /* Try to find matching entry in table
 255          * Maybe should check application types first to
 256          * allow application override? Might also be useful
 257          * to have a flag which indicates table is sorted and
 258          * we can do a binary search. For now stick to a
 259          * linear search.
 260          */
 261 
 262         for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
 263                 if (atbl->value == selector)
 264                         return &atbl->tt;
 265 
 266         /* FIXME: need to search application table too */
 267 
 268         /* No match, return default type */
 269         if (!adb->default_tt)
 270                 goto err;               
 271         return adb->default_tt;
 272         
 273         err:
 274         /* FIXME: should log the value or OID of unsupported type */
 275         if (nullerr)
 276                 ASN1err(ASN1_F_ASN1_DO_ADB,
 277                         ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 278         return NULL;
 279         }