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      1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      2  * All rights reserved.
      3  *
      4  * This package is an SSL implementation written
      5  * by Eric Young (eay (at) cryptsoft.com).
      6  * The implementation was written so as to conform with Netscapes SSL.
      7  *
      8  * This library is free for commercial and non-commercial use as long as
      9  * the following conditions are aheared to.  The following conditions
     10  * apply to all code found in this distribution, be it the RC4, RSA,
     11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     12  * included with this distribution is covered by the same copyright terms
     13  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     14  *
     15  * Copyright remains Eric Young's, and as such any Copyright notices in
     16  * the code are not to be removed.
     17  * If this package is used in a product, Eric Young should be given attribution
     18  * as the author of the parts of the library used.
     19  * This can be in the form of a textual message at program startup or
     20  * in documentation (online or textual) provided with the package.
     21  *
     22  * Redistribution and use in source and binary forms, with or without
     23  * modification, are permitted provided that the following conditions
     24  * are met:
     25  * 1. Redistributions of source code must retain the copyright
     26  *    notice, this list of conditions and the following disclaimer.
     27  * 2. Redistributions in binary form must reproduce the above copyright
     28  *    notice, this list of conditions and the following disclaimer in the
     29  *    documentation and/or other materials provided with the distribution.
     30  * 3. All advertising materials mentioning features or use of this software
     31  *    must display the following acknowledgement:
     32  *    "This product includes cryptographic software written by
     33  *     Eric Young (eay (at) cryptsoft.com)"
     34  *    The word 'cryptographic' can be left out if the rouines from the library
     35  *    being used are not cryptographic related :-).
     36  * 4. If you include any Windows specific code (or a derivative thereof) from
     37  *    the apps directory (application code) you must include an acknowledgement:
     38  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     39  *
     40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     50  * SUCH DAMAGE.
     51  *
     52  * The licence and distribution terms for any publically available version or
     53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     54  * copied and put under another distribution licence
     55  * [including the GNU Public Licence.] */
     56 
     57 #include <openssl/asn1.h>
     58 
     59 #include <string.h>
     60 
     61 #include <openssl/asn1t.h>
     62 #include <openssl/mem.h>
     63 #include <openssl/obj.h>
     64 #include <openssl/err.h>
     65 #include <openssl/thread.h>
     66 
     67 #include "../internal.h"
     68 
     69 
     70 /* Utility functions for manipulating fields and offsets */
     71 
     72 /* Add 'offset' to 'addr' */
     73 #define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)
     74 
     75 /* Given an ASN1_ITEM CHOICE type return the selector value */
     76 int asn1_get_choice_selector(ASN1_VALUE **pval, const ASN1_ITEM *it) {
     77   int *sel = offset2ptr(*pval, it->utype);
     78   return *sel;
     79 }
     80 
     81 /* Given an ASN1_ITEM CHOICE type set the selector value, return old value. */
     82 int asn1_set_choice_selector(ASN1_VALUE **pval, int value,
     83                              const ASN1_ITEM *it) {
     84   int *sel, ret;
     85   sel = offset2ptr(*pval, it->utype);
     86   ret = *sel;
     87   *sel = value;
     88   return ret;
     89 }
     90 
     91 static CRYPTO_refcount_t *asn1_get_references(ASN1_VALUE **pval,
     92                                               const ASN1_ITEM *it) {
     93   if (it->itype != ASN1_ITYPE_SEQUENCE &&
     94       it->itype != ASN1_ITYPE_NDEF_SEQUENCE) {
     95     return NULL;
     96   }
     97   const ASN1_AUX *aux = it->funcs;
     98   if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT)) {
     99     return NULL;
    100   }
    101   return offset2ptr(*pval, aux->ref_offset);
    102 }
    103 
    104 void asn1_refcount_set_one(ASN1_VALUE **pval, const ASN1_ITEM *it) {
    105   CRYPTO_refcount_t *references = asn1_get_references(pval, it);
    106   if (references != NULL) {
    107     *references = 1;
    108   }
    109 }
    110 
    111 int asn1_refcount_dec_and_test_zero(ASN1_VALUE **pval, const ASN1_ITEM *it) {
    112   CRYPTO_refcount_t *references = asn1_get_references(pval, it);
    113   if (references != NULL) {
    114     return CRYPTO_refcount_dec_and_test_zero(references);
    115   }
    116   return 1;
    117 }
    118 
    119 static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it) {
    120   const ASN1_AUX *aux;
    121   if (!pval || !*pval) {
    122     return NULL;
    123   }
    124   aux = it->funcs;
    125   if (!aux || !(aux->flags & ASN1_AFLG_ENCODING)) {
    126     return NULL;
    127   }
    128   return offset2ptr(*pval, aux->enc_offset);
    129 }
    130 
    131 void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it) {
    132   ASN1_ENCODING *enc;
    133   enc = asn1_get_enc_ptr(pval, it);
    134   if (enc) {
    135     enc->enc = NULL;
    136     enc->len = 0;
    137     enc->modified = 1;
    138   }
    139 }
    140 
    141 void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it) {
    142   ASN1_ENCODING *enc;
    143   enc = asn1_get_enc_ptr(pval, it);
    144   if (enc) {
    145     if (enc->enc) {
    146       OPENSSL_free(enc->enc);
    147     }
    148     enc->enc = NULL;
    149     enc->len = 0;
    150     enc->modified = 1;
    151   }
    152 }
    153 
    154 int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
    155                   const ASN1_ITEM *it) {
    156   ASN1_ENCODING *enc;
    157   enc = asn1_get_enc_ptr(pval, it);
    158   if (!enc) {
    159     return 1;
    160   }
    161 
    162   if (enc->enc) {
    163     OPENSSL_free(enc->enc);
    164   }
    165   enc->enc = OPENSSL_malloc(inlen);
    166   if (!enc->enc) {
    167     return 0;
    168   }
    169   memcpy(enc->enc, in, inlen);
    170   enc->len = inlen;
    171   enc->modified = 0;
    172 
    173   return 1;
    174 }
    175 
    176 int asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,
    177                      const ASN1_ITEM *it) {
    178   ASN1_ENCODING *enc;
    179   enc = asn1_get_enc_ptr(pval, it);
    180   if (!enc || enc->modified) {
    181     return 0;
    182   }
    183   if (out) {
    184     memcpy(*out, enc->enc, enc->len);
    185     *out += enc->len;
    186   }
    187   if (len) {
    188     *len = enc->len;
    189   }
    190   return 1;
    191 }
    192 
    193 /* Given an ASN1_TEMPLATE get a pointer to a field */
    194 ASN1_VALUE **asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt) {
    195   ASN1_VALUE **pvaltmp;
    196   if (tt->flags & ASN1_TFLG_COMBINE) {
    197     return pval;
    198   }
    199   pvaltmp = offset2ptr(*pval, tt->offset);
    200   /* NOTE for BOOLEAN types the field is just a plain int so we can't return
    201    * int **, so settle for (int *). */
    202   return pvaltmp;
    203 }
    204 
    205 /* Handle ANY DEFINED BY template, find the selector, look up the relevant
    206  * ASN1_TEMPLATE in the table and return it. */
    207 const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt,
    208                                  int nullerr) {
    209   const ASN1_ADB *adb;
    210   const ASN1_ADB_TABLE *atbl;
    211   long selector;
    212   ASN1_VALUE **sfld;
    213   int i;
    214   if (!(tt->flags & ASN1_TFLG_ADB_MASK)) {
    215     return tt;
    216   }
    217 
    218   /* Else ANY DEFINED BY ... get the table */
    219   adb = ASN1_ADB_ptr(tt->item);
    220 
    221   /* Get the selector field */
    222   sfld = offset2ptr(*pval, adb->offset);
    223 
    224   /* Check if NULL */
    225   if (!sfld) {
    226     if (!adb->null_tt) {
    227       goto err;
    228     }
    229     return adb->null_tt;
    230   }
    231 
    232   /* Convert type to a long:
    233    * NB: don't check for NID_undef here because it
    234    * might be a legitimate value in the table */
    235   if (tt->flags & ASN1_TFLG_ADB_OID) {
    236     selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
    237   } else {
    238     selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
    239   }
    240 
    241   /* Try to find matching entry in table Maybe should check application types
    242    * first to allow application override? Might also be useful to have a flag
    243    * which indicates table is sorted and we can do a binary search. For now
    244    * stick to a linear search. */
    245 
    246   for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++) {
    247     if (atbl->value == selector) {
    248       return &atbl->tt;
    249     }
    250   }
    251 
    252   /* FIXME: need to search application table too */
    253 
    254   /* No match, return default type */
    255   if (!adb->default_tt) {
    256     goto err;
    257   }
    258   return adb->default_tt;
    259 
    260 err:
    261   /* FIXME: should log the value or OID of unsupported type */
    262   if (nullerr) {
    263     OPENSSL_PUT_ERROR(ASN1, asn1_do_adb,
    264                       ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
    265   }
    266   return NULL;
    267 }
    268