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_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     CRYPTO_REF_COUNT *lck;
  62     CRYPTO_RWLOCK **lock;
  63     int ret = -1;
  64
  65     if ((it->itype != ASN1_ITYPE_SEQUENCE)
  66         && (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))
  67         return 0;
  68     aux = it->funcs;
  69     if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT))
  70         return 0;
  71     lck = offset2ptr(*pval, aux->ref_offset);
  72     lock = offset2ptr(*pval, aux->ref_lock);
  73
  74     switch (op) {
  75     case 0:
  76         *lck = ret = 1;
  77         *lock = CRYPTO_THREAD_lock_new();
  78         if (*lock == NULL) {
  79             ASN1err(ASN1_F_ASN1_DO_LOCK, ERR_R_MALLOC_FAILURE);
  80             return -1;
  81         }
  82         break;
  83     case 1:
  84         if (!CRYPTO_UP_REF(lck, &ret, *lock))
  85             return -1;
  86         break;
  87     case -1:
  88         if (!CRYPTO_DOWN_REF(lck, &ret, *lock))
  89             return -1;  /* failed */
  90 #ifdef REF_PRINT
  91         fprintf(stderr, "%p:%4d:%s\n", it, ret, it->sname);
  92 #endif
  93         REF_ASSERT_ISNT(ret < 0);
  94         if (ret == 0) {
  95             CRYPTO_THREAD_lock_free(*lock);
  96             *lock = NULL;
  97         }
  98         break;
  99     }
 100
 101     return ret;
 102 }
 103
 104 static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
 105 {
 106     const ASN1_AUX *aux;
 107     if (!pval || !*pval)
 108         return NULL;
 109     aux = it->funcs;
 110     if (!aux || !(aux->flags & ASN1_AFLG_ENCODING))
 111         return NULL;
 112     return offset2ptr(*pval, aux->enc_offset);
 113 }
 114
 115 void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
 116 {
 117     ASN1_ENCODING *enc;
 118     enc = asn1_get_enc_ptr(pval, it);
 119     if (enc) {
 120         enc->enc = NULL;
 121         enc->len = 0;
 122         enc->modified = 1;
 123     }
 124 }
 125
 126 void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
 127 {
 128     ASN1_ENCODING *enc;
 129     enc = asn1_get_enc_ptr(pval, it);
 130     if (enc) {
 131         OPENSSL_free(enc->enc);
 132         enc->enc = NULL;
 133         enc->len = 0;
 134         enc->modified = 1;
 135     }
 136 }
 137
 138 int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
 139                   const ASN1_ITEM *it)
 140 {
 141     ASN1_ENCODING *enc;
 142     enc = asn1_get_enc_ptr(pval, it);
 143     if (!enc)
 144         return 1;
 145
 146     OPENSSL_free(enc->enc);
 147     if ((enc->enc = OPENSSL_malloc(inlen)) == NULL) {
 148         ASN1err(ASN1_F_ASN1_ENC_SAVE, ERR_R_MALLOC_FAILURE);
 149         return 0;
 150     }
 151     memcpy(enc->enc, in, inlen);
 152     enc->len = inlen;
 153     enc->modified = 0;
 154
 155     return 1;
 156 }
 157
 158 int asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,
 159                      const ASN1_ITEM *it)
 160 {
 161     ASN1_ENCODING *enc;
 162     enc = asn1_get_enc_ptr(pval, it);
 163     if (!enc || enc->modified)
 164         return 0;
 165     if (out) {
 166         memcpy(*out, enc->enc, enc->len);
 167         *out += enc->len;
 168     }
 169     if (len)
 170         *len = enc->len;
 171     return 1;
 172 }
 173
 174 /* Given an ASN1_TEMPLATE get a pointer to a field */
 175 ASN1_VALUE **asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
 176 {
 177     ASN1_VALUE **pvaltmp;
 178     pvaltmp = offset2ptr(*pval, tt->offset);
 179     /*
 180      * NOTE for BOOLEAN types the field is just a plain int so we can't
 181      * return int **, so settle for (int *).
 182      */
 183     return pvaltmp;
 184 }
 185
 186 /*
 187  * Handle ANY DEFINED BY template, find the selector, look up the relevant
 188  * ASN1_TEMPLATE in the table and return it.
 189  */
 190
 191 const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt,
 192                                  int nullerr)
 193 {
 194     const ASN1_ADB *adb;
 195     const ASN1_ADB_TABLE *atbl;
 196     long selector;
 197     ASN1_VALUE **sfld;
 198     int i;
 199     if (!(tt->flags & ASN1_TFLG_ADB_MASK))
 200         return tt;
 201
 202     /* Else ANY DEFINED BY ... get the table */
 203     adb = ASN1_ADB_ptr(tt->item);
 204
 205     /* Get the selector field */
 206     sfld = offset2ptr(*pval, adb->offset);
 207
 208     /* Check if NULL */
 209     if (*sfld == NULL) {
 210         if (!adb->null_tt)
 211             goto err;
 212         return adb->null_tt;
 213     }
 214
 215     /*
 216      * Convert type to a long: NB: don't check for NID_undef here because it
 217      * might be a legitimate value in the table
 218      */
 219     if (tt->flags & ASN1_TFLG_ADB_OID)
 220         selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
 221     else
 222         selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
 223
 224     /* Let application callback translate value */
 225     if (adb->adb_cb != NULL && adb->adb_cb(&selector) == 0) {
 226         ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 227         return NULL;
 228     }
 229
 230     /*
 231      * Try to find matching entry in table Maybe should check application
 232      * types first to allow application override? Might also be useful to
 233      * have a flag which indicates table is sorted and we can do a binary
 234      * search. For now stick to a linear search.
 235      */
 236
 237     for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
 238         if (atbl->value == selector)
 239             return &atbl->tt;
 240
 241     /* FIXME: need to search application table too */
 242
 243     /* No match, return default type */
 244     if (!adb->default_tt)
 245         goto err;
 246     return adb->default_tt;
 247
 248  err:
 249     /* FIXME: should log the value or OID of unsupported type */
 250     if (nullerr)
 251         ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 252     return NULL;
 253 }