crypto/asn1/tasn_utl.c

   1 /*
   2  * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stddef.h>
  11 #include <string.h>
  12 #include <internal/cryptlib.h>
  13 #include <openssl/asn1.h>
  14 #include <openssl/asn1t.h>
  15 #include <openssl/objects.h>
  16 #include <openssl/err.h>
  17 #include "asn1_locl.h"
  18
  19 /* Utility functions for manipulating fields and offsets */
  20
  21 /* Add 'offset' to 'addr' */
  22 #define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)
  23
  24 /*
  25  * Given an ASN1_ITEM CHOICE type return the selector value
  26  */
  27
  28 int asn1_get_choice_selector(ASN1_VALUE **pval, const ASN1_ITEM *it)
  29 {
  30     int *sel = offset2ptr(*pval, it->utype);
  31     return *sel;
  32 }
  33
  34 /*
  35  * Given an ASN1_ITEM CHOICE type set the selector value, return old value.
  36  */
  37
  38 int asn1_set_choice_selector(ASN1_VALUE **pval, int value,
  39                              const ASN1_ITEM *it)
  40 {
  41     int *sel, ret;
  42     sel = offset2ptr(*pval, it->utype);
  43     ret = *sel;
  44     *sel = value;
  45     return ret;
  46 }
  47
  48 /*
  49  * Do reference counting. The value 'op' decides what to do. if it is +1
  50  * then the count is incremented. If op is 0 count is set to 1. If op is -1
  51  * count is decremented and the return value is the current reference count
  52  * or 0 if no reference count exists.
  53  */
  54
  55 int asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)
  56 {
  57     const ASN1_AUX *aux;
  58     int *lck, ret;
  59     CRYPTO_RWLOCK **lock;
  60     if ((it->itype != ASN1_ITYPE_SEQUENCE)
  61         && (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))
  62         return 0;
  63     aux = it->funcs;
  64     if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT))
  65         return 0;
  66     lck = offset2ptr(*pval, aux->ref_offset);
  67     lock = offset2ptr(*pval, aux->ref_lock);
  68     if (op == 0) {
  69         *lck = 1;
  70         *lock = CRYPTO_THREAD_lock_new();
  71         if (*lock == NULL)
  72             return 0;
  73         return 1;
  74     }
  75     CRYPTO_atomic_add(lck, op, &ret, *lock);
  76 #ifdef REF_PRINT
  77     fprintf(stderr, "%p:%4d:%s\n", it, *lck, it->sname);
  78 #endif
  79     REF_ASSERT_ISNT(ret < 0);
  80     if (ret == 0)
  81         CRYPTO_THREAD_lock_free(*lock);
  82     return ret;
  83 }
  84
  85 static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
  86 {
  87     const ASN1_AUX *aux;
  88     if (!pval || !*pval)
  89         return NULL;
  90     aux = it->funcs;
  91     if (!aux || !(aux->flags & ASN1_AFLG_ENCODING))
  92         return NULL;
  93     return offset2ptr(*pval, aux->enc_offset);
  94 }
  95
  96 void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
  97 {
  98     ASN1_ENCODING *enc;
  99     enc = asn1_get_enc_ptr(pval, it);
 100     if (enc) {
 101         enc->enc = NULL;
 102         enc->len = 0;
 103         enc->modified = 1;
 104     }
 105 }
 106
 107 void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
 108 {
 109     ASN1_ENCODING *enc;
 110     enc = asn1_get_enc_ptr(pval, it);
 111     if (enc) {
 112         OPENSSL_free(enc->enc);
 113         enc->enc = NULL;
 114         enc->len = 0;
 115         enc->modified = 1;
 116     }
 117 }
 118
 119 int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
 120                   const ASN1_ITEM *it)
 121 {
 122     ASN1_ENCODING *enc;
 123     enc = asn1_get_enc_ptr(pval, it);
 124     if (!enc)
 125         return 1;
 126
 127     OPENSSL_free(enc->enc);
 128     enc->enc = OPENSSL_malloc(inlen);
 129     if (enc->enc == NULL)
 130         return 0;
 131     memcpy(enc->enc, in, inlen);
 132     enc->len = inlen;
 133     enc->modified = 0;
 134
 135     return 1;
 136 }
 137
 138 int asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,
 139                      const ASN1_ITEM *it)
 140 {
 141     ASN1_ENCODING *enc;
 142     enc = asn1_get_enc_ptr(pval, it);
 143     if (!enc || enc->modified)
 144         return 0;
 145     if (out) {
 146         memcpy(*out, enc->enc, enc->len);
 147         *out += enc->len;
 148     }
 149     if (len)
 150         *len = enc->len;
 151     return 1;
 152 }
 153
 154 /* Given an ASN1_TEMPLATE get a pointer to a field */
 155 ASN1_VALUE **asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
 156 {
 157     ASN1_VALUE **pvaltmp;
 158     pvaltmp = offset2ptr(*pval, tt->offset);
 159     /*
 160      * NOTE for BOOLEAN types the field is just a plain int so we can't
 161      * return int **, so settle for (int *).
 162      */
 163     return pvaltmp;
 164 }
 165
 166 /*
 167  * Handle ANY DEFINED BY template, find the selector, look up the relevant
 168  * ASN1_TEMPLATE in the table and return it.
 169  */
 170
 171 const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt,
 172                                  int nullerr)
 173 {
 174     const ASN1_ADB *adb;
 175     const ASN1_ADB_TABLE *atbl;
 176     long selector;
 177     ASN1_VALUE **sfld;
 178     int i;
 179     if (!(tt->flags & ASN1_TFLG_ADB_MASK))
 180         return tt;
 181
 182     /* Else ANY DEFINED BY ... get the table */
 183     adb = ASN1_ADB_ptr(tt->item);
 184
 185     /* Get the selector field */
 186     sfld = offset2ptr(*pval, adb->offset);
 187
 188     /* Check if NULL */
 189     if (!sfld) {
 190         if (!adb->null_tt)
 191             goto err;
 192         return adb->null_tt;
 193     }
 194
 195     /*
 196      * Convert type to a long: NB: don't check for NID_undef here because it
 197      * might be a legitimate value in the table
 198      */
 199     if (tt->flags & ASN1_TFLG_ADB_OID)
 200         selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
 201     else
 202         selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
 203
 204     /* Let application callback translate value */
 205     if (adb->adb_cb != NULL && adb->adb_cb(&selector) == 0) {
 206         ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 207         return NULL;
 208     }
 209
 210     /*
 211      * Try to find matching entry in table Maybe should check application
 212      * types first to allow application override? Might also be useful to
 213      * have a flag which indicates table is sorted and we can do a binary
 214      * search. For now stick to a linear search.
 215      */
 216
 217     for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
 218         if (atbl->value == selector)
 219             return &atbl->tt;
 220
 221     /* FIXME: need to search application table too */
 222
 223     /* No match, return default type */
 224     if (!adb->default_tt)
 225         goto err;
 226     return adb->default_tt;
 227
 228  err:
 229     /* FIXME: should log the value or OID of unsupported type */
 230     if (nullerr)
 231         ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 232     return NULL;
 233 }