crypto/asn1/tasn_utl.c

   1 /*
   2  * Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 "internal/refcount.h"
  14 #include <openssl/asn1.h>
  15 #include <openssl/asn1t.h>
  16 #include <openssl/objects.h>
  17 #include <openssl/err.h>
  18 #include "asn1_local.h"
  19
  20 /* Utility functions for manipulating fields and offsets */
  21
  22 /* Add 'offset' to 'addr' */
  23 #define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)
  24
  25 /*
  26  * Given an ASN1_ITEM CHOICE type return the selector value
  27  */
  28
  29 int asn1_get_choice_selector(ASN1_VALUE **pval, const ASN1_ITEM *it)
  30 {
  31     int *sel = offset2ptr(*pval, it->utype);
  32
  33     return *sel;
  34 }
  35
  36 int asn1_get_choice_selector_const(const ASN1_VALUE **pval, const ASN1_ITEM *it)
  37 {
  38     int *sel = offset2ptr(*pval, it->utype);
  39
  40     return *sel;
  41 }
  42
  43 /*
  44  * Given an ASN1_ITEM CHOICE type set the selector value, return old value.
  45  */
  46
  47 int asn1_set_choice_selector(ASN1_VALUE **pval, int value,
  48                              const ASN1_ITEM *it)
  49 {
  50     int *sel, ret;
  51
  52     sel = offset2ptr(*pval, it->utype);
  53     ret = *sel;
  54     *sel = value;
  55     return ret;
  56 }
  57
  58 /*
  59  * Do atomic reference counting. The value 'op' decides what to do.
  60  * If it is +1 then the count is incremented.
  61  * If |op| is 0, lock is initialised and count is set to 1.
  62  * If |op| is -1, count is decremented and the return value is the current
  63  * reference count or 0 if no reference count is active.
  64  * It returns -1 on initialisation error.
  65  * Used by ASN1_SEQUENCE construct of X509, X509_REQ, X509_CRL objects
  66  */
  67 int asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)
  68 {
  69     const ASN1_AUX *aux;
  70     CRYPTO_REF_COUNT *lck;
  71     CRYPTO_RWLOCK **lock;
  72     int ret = -1;
  73
  74     if ((it->itype != ASN1_ITYPE_SEQUENCE)
  75         && (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))
  76         return 0;
  77     aux = it->funcs;
  78     if (aux == NULL || (aux->flags & ASN1_AFLG_REFCOUNT) == 0)
  79         return 0;
  80     lck = offset2ptr(*pval, aux->ref_offset);
  81     lock = offset2ptr(*pval, aux->ref_lock);
  82
  83     switch (op) {
  84     case 0:
  85         *lck = ret = 1;
  86         *lock = CRYPTO_THREAD_lock_new();
  87         if (*lock == NULL) {
  88             ASN1err(ASN1_F_ASN1_DO_LOCK, ERR_R_MALLOC_FAILURE);
  89             return -1;
  90         }
  91         break;
  92     case 1:
  93         if (!CRYPTO_UP_REF(lck, &ret, *lock))
  94             return -1;
  95         break;
  96     case -1:
  97         if (!CRYPTO_DOWN_REF(lck, &ret, *lock))
  98             return -1;  /* failed */
  99 #ifdef REF_PRINT
 100         fprintf(stderr, "%p:%4d:%s\n", it, ret, it->sname);
 101 #endif
 102         REF_ASSERT_ISNT(ret < 0);
 103         if (ret == 0) {
 104             CRYPTO_THREAD_lock_free(*lock);
 105             *lock = NULL;
 106         }
 107         break;
 108     }
 109
 110     return ret;
 111 }
 112
 113 static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
 114 {
 115     const ASN1_AUX *aux;
 116
 117     if (pval == NULL || *pval == NULL)
 118         return NULL;
 119     aux = it->funcs;
 120     if (aux == NULL || (aux->flags & ASN1_AFLG_ENCODING) == 0)
 121         return NULL;
 122     return offset2ptr(*pval, aux->enc_offset);
 123 }
 124
 125 static const ASN1_ENCODING *asn1_get_const_enc_ptr(const ASN1_VALUE **pval,
 126                                                    const ASN1_ITEM *it)
 127 {
 128     const ASN1_AUX *aux;
 129
 130     if (pval == NULL || *pval == NULL)
 131         return NULL;
 132     aux = it->funcs;
 133     if (aux == NULL || (aux->flags & ASN1_AFLG_ENCODING) == 0)
 134         return NULL;
 135     return offset2ptr(*pval, aux->enc_offset);
 136 }
 137
 138 void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
 139 {
 140     ASN1_ENCODING *enc = asn1_get_enc_ptr(pval, it);
 141
 142     if (enc != NULL) {
 143         enc->enc = NULL;
 144         enc->len = 0;
 145         enc->modified = 1;
 146     }
 147 }
 148
 149 void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
 150 {
 151     ASN1_ENCODING *enc = asn1_get_enc_ptr(pval, it);
 152
 153     if (enc != NULL) {
 154         OPENSSL_free(enc->enc);
 155         enc->enc = NULL;
 156         enc->len = 0;
 157         enc->modified = 1;
 158     }
 159 }
 160
 161 int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
 162                   const ASN1_ITEM *it)
 163 {
 164     ASN1_ENCODING *enc = asn1_get_enc_ptr(pval, it);
 165
 166     if (enc == NULL)
 167         return 1;
 168
 169     OPENSSL_free(enc->enc);
 170     if ((enc->enc = OPENSSL_malloc(inlen)) == NULL) {
 171         ASN1err(ASN1_F_ASN1_ENC_SAVE, ERR_R_MALLOC_FAILURE);
 172         return 0;
 173     }
 174     memcpy(enc->enc, in, inlen);
 175     enc->len = inlen;
 176     enc->modified = 0;
 177
 178     return 1;
 179 }
 180
 181 int asn1_enc_restore(int *len, unsigned char **out, const ASN1_VALUE **pval,
 182                      const ASN1_ITEM *it)
 183 {
 184     const ASN1_ENCODING *enc = asn1_get_const_enc_ptr(pval, it);
 185
 186     if (enc == NULL || enc->modified)
 187         return 0;
 188     if (out) {
 189         memcpy(*out, enc->enc, enc->len);
 190         *out += enc->len;
 191     }
 192     if (len != NULL)
 193         *len = enc->len;
 194     return 1;
 195 }
 196
 197 /* Given an ASN1_TEMPLATE get a pointer to a field */
 198 ASN1_VALUE **asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
 199 {
 200     ASN1_VALUE **pvaltmp = offset2ptr(*pval, tt->offset);
 201
 202     /*
 203      * NOTE for BOOLEAN types the field is just a plain int so we can't
 204      * return int **, so settle for (int *).
 205      */
 206     return pvaltmp;
 207 }
 208
 209 /* Given an ASN1_TEMPLATE get a const pointer to a field */
 210 const ASN1_VALUE **asn1_get_const_field_ptr(const ASN1_VALUE **pval,
 211                                             const ASN1_TEMPLATE *tt)
 212 {
 213     return offset2ptr(*pval, tt->offset);
 214 }
 215
 216 /*
 217  * Handle ANY DEFINED BY template, find the selector, look up the relevant
 218  * ASN1_TEMPLATE in the table and return it.
 219  */
 220
 221 const ASN1_TEMPLATE *asn1_do_adb(const ASN1_VALUE *val,
 222                                  const ASN1_TEMPLATE *tt,
 223                                  int nullerr)
 224 {
 225     const ASN1_ADB *adb;
 226     const ASN1_ADB_TABLE *atbl;
 227     long selector;
 228     const ASN1_VALUE **sfld;
 229     int i;
 230
 231     if ((tt->flags & ASN1_TFLG_ADB_MASK) == 0)
 232         return tt;
 233
 234     /* Else ANY DEFINED BY ... get the table */
 235     adb = ASN1_ADB_ptr(tt->item);
 236
 237     /* Get the selector field */
 238     sfld = offset2ptr(val, adb->offset);
 239
 240     /* Check if NULL */
 241     if (*sfld == NULL) {
 242         if (adb->null_tt == NULL)
 243             goto err;
 244         return adb->null_tt;
 245     }
 246
 247     /*
 248      * Convert type to a long: 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) != 0)
 252         selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
 253     else
 254         selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
 255
 256     /* Let application callback translate value */
 257     if (adb->adb_cb != NULL && adb->adb_cb(&selector) == 0) {
 258         ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 259         return NULL;
 260     }
 261
 262     /*
 263      * Try to find matching entry in table Maybe should check application
 264      * types first to allow application override? Might also be useful to
 265      * have a flag which indicates table is sorted and we can do a binary
 266      * search. For now stick to a linear search.
 267      */
 268
 269     for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
 270         if (atbl->value == selector)
 271             return &atbl->tt;
 272
 273     /* FIXME: need to search application table too */
 274
 275     /* No match, return default type */
 276     if (!adb->default_tt)
 277         goto err;
 278     return adb->default_tt;
 279
 280  err:
 281     /* FIXME: should log the value or OID of unsupported type */
 282     if (nullerr)
 283         ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 284     return NULL;
 285 }