crypto/asn1/tasn_utl.c

   1 /*
   2  * Copyright 2000-2017 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 "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_locl.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     return *sel;
  33 }
  34
  35 /*
  36  * Given an ASN1_ITEM CHOICE type set the selector value, return old value.
  37  */
  38
  39 int asn1_set_choice_selector(ASN1_VALUE **pval, int value,
  40                              const ASN1_ITEM *it)
  41 {
  42     int *sel, ret;
  43     sel = offset2ptr(*pval, it->utype);
  44     ret = *sel;
  45     *sel = value;
  46     return ret;
  47 }
  48
  49 /*
  50  * Do atomic reference counting. The value 'op' decides what to do.
  51  * If it is +1 then the count is incremented.
  52  * If |op| is 0, lock is initialised and count is set to 1.
  53  * If |op| is -1, count is decremented and the return value is the current
  54  * reference count or 0 if no reference count is active.
  55  * It returns -1 on initialisation error.
  56  * Used by ASN1_SEQUENCE construct of X509, X509_REQ, X509_CRL objects
  57  */
  58 int asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)
  59 {
  60     const ASN1_AUX *aux;
  61     int *lck, ret;
  62     CRYPTO_RWLOCK **lock;
  63     if ((it->itype != ASN1_ITYPE_SEQUENCE)
  64         && (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))
  65         return 0;
  66     aux = it->funcs;
  67     if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT))
  68         return 0;
  69     lck = offset2ptr(*pval, aux->ref_offset);
  70     lock = offset2ptr(*pval, aux->ref_lock);
  71     if (op == 0) {
  72         *lck = 1;
  73         *lock = CRYPTO_THREAD_lock_new();
  74         if (*lock == NULL) {
  75             ASN1err(ASN1_F_ASN1_DO_LOCK, ERR_R_MALLOC_FAILURE);
  76             return -1;
  77         }
  78         return 1;
  79     }
  80     if (CRYPTO_atomic_add(lck, op, &ret, *lock) < 0)
  81         return -1;  /* failed */
  82 #ifdef REF_PRINT
  83     fprintf(stderr, "%p:%4d:%s\n", it, *lck, it->sname);
  84 #endif
  85     REF_ASSERT_ISNT(ret < 0);
  86     if (ret == 0) {
  87         CRYPTO_THREAD_lock_free(*lock);
  88         *lock = NULL;
  89     }
  90     return ret;
  91 }
  92
  93 static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
  94 {
  95     const ASN1_AUX *aux;
  96     if (!pval || !*pval)
  97         return NULL;
  98     aux = it->funcs;
  99     if (!aux || !(aux->flags & ASN1_AFLG_ENCODING))
 100         return NULL;
 101     return offset2ptr(*pval, aux->enc_offset);
 102 }
 103
 104 void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
 105 {
 106     ASN1_ENCODING *enc;
 107     enc = asn1_get_enc_ptr(pval, it);
 108     if (enc) {
 109         enc->enc = NULL;
 110         enc->len = 0;
 111         enc->modified = 1;
 112     }
 113 }
 114
 115 void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
 116 {
 117     ASN1_ENCODING *enc;
 118     enc = asn1_get_enc_ptr(pval, it);
 119     if (enc) {
 120         OPENSSL_free(enc->enc);
 121         enc->enc = NULL;
 122         enc->len = 0;
 123         enc->modified = 1;
 124     }
 125 }
 126
 127 int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
 128                   const ASN1_ITEM *it)
 129 {
 130     ASN1_ENCODING *enc;
 131     enc = asn1_get_enc_ptr(pval, it);
 132     if (!enc)
 133         return 1;
 134
 135     OPENSSL_free(enc->enc);
 136     if ((enc->enc = OPENSSL_malloc(inlen)) == NULL) {
 137         ASN1err(ASN1_F_ASN1_ENC_SAVE, ERR_R_MALLOC_FAILURE);
 138         return 0;
 139     }
 140     memcpy(enc->enc, in, inlen);
 141     enc->len = inlen;
 142     enc->modified = 0;
 143
 144     return 1;
 145 }
 146
 147 int asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,
 148                      const ASN1_ITEM *it)
 149 {
 150     ASN1_ENCODING *enc;
 151     enc = asn1_get_enc_ptr(pval, it);
 152     if (!enc || enc->modified)
 153         return 0;
 154     if (out) {
 155         memcpy(*out, enc->enc, enc->len);
 156         *out += enc->len;
 157     }
 158     if (len)
 159         *len = enc->len;
 160     return 1;
 161 }
 162
 163 /* Given an ASN1_TEMPLATE get a pointer to a field */
 164 ASN1_VALUE **asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
 165 {
 166     ASN1_VALUE **pvaltmp;
 167     pvaltmp = offset2ptr(*pval, tt->offset);
 168     /*
 169      * NOTE for BOOLEAN types the field is just a plain int so we can't
 170      * return int **, so settle for (int *).
 171      */
 172     return pvaltmp;
 173 }
 174
 175 /*
 176  * Handle ANY DEFINED BY template, find the selector, look up the relevant
 177  * ASN1_TEMPLATE in the table and return it.
 178  */
 179
 180 const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt,
 181                                  int nullerr)
 182 {
 183     const ASN1_ADB *adb;
 184     const ASN1_ADB_TABLE *atbl;
 185     long selector;
 186     ASN1_VALUE **sfld;
 187     int i;
 188     if (!(tt->flags & ASN1_TFLG_ADB_MASK))
 189         return tt;
 190
 191     /* Else ANY DEFINED BY ... get the table */
 192     adb = ASN1_ADB_ptr(tt->item);
 193
 194     /* Get the selector field */
 195     sfld = offset2ptr(*pval, adb->offset);
 196
 197     /* Check if NULL */
 198     if (*sfld == NULL) {
 199         if (!adb->null_tt)
 200             goto err;
 201         return adb->null_tt;
 202     }
 203
 204     /*
 205      * Convert type to a long: NB: don't check for NID_undef here because it
 206      * might be a legitimate value in the table
 207      */
 208     if (tt->flags & ASN1_TFLG_ADB_OID)
 209         selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
 210     else
 211         selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
 212
 213     /* Let application callback translate value */
 214     if (adb->adb_cb != NULL && adb->adb_cb(&selector) == 0) {
 215         ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 216         return NULL;
 217     }
 218
 219     /*
 220      * Try to find matching entry in table Maybe should check application
 221      * types first to allow application override? Might also be useful to
 222      * have a flag which indicates table is sorted and we can do a binary
 223      * search. For now stick to a linear search.
 224      */
 225
 226     for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
 227         if (atbl->value == selector)
 228             return &atbl->tt;
 229
 230     /* FIXME: need to search application table too */
 231
 232     /* No match, return default type */
 233     if (!adb->default_tt)
 234         goto err;
 235     return adb->default_tt;
 236
 237  err:
 238     /* FIXME: should log the value or OID of unsupported type */
 239     if (nullerr)
 240         ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 241     return NULL;
 242 }