crypto/asn1/tasn_utl.c

   1 /*
   2  * Copyright 2000-2021 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 ossl_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 ossl_asn1_get_choice_selector_const(const ASN1_VALUE **pval,
  37                                         const ASN1_ITEM *it)
  38 {
  39     int *sel = offset2ptr(*pval, it->utype);
  40
  41     return *sel;
  42 }
  43
  44 /*
  45  * Given an ASN1_ITEM CHOICE type set the selector value, return old value.
  46  */
  47
  48 int ossl_asn1_set_choice_selector(ASN1_VALUE **pval, int value,
  49                                   const ASN1_ITEM *it)
  50 {
  51     int *sel, ret;
  52
  53     sel = offset2ptr(*pval, it->utype);
  54     ret = *sel;
  55     *sel = value;
  56     return ret;
  57 }
  58
  59 /*
  60  * Do atomic reference counting. The value 'op' decides what to do.
  61  * If it is +1 then the count is incremented.
  62  * If |op| is 0, lock is initialised and count is set to 1.
  63  * If |op| is -1, count is decremented and the return value is the current
  64  * reference count or 0 if no reference count is active.
  65  * It returns -1 on initialisation error.
  66  * Used by ASN1_SEQUENCE construct of X509, X509_REQ, X509_CRL objects
  67  */
  68 int ossl_asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)
  69 {
  70     const ASN1_AUX *aux;
  71     CRYPTO_REF_COUNT *lck;
  72     CRYPTO_RWLOCK **lock;
  73     int ret = -1;
  74
  75     if ((it->itype != ASN1_ITYPE_SEQUENCE)
  76         && (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))
  77         return 0;
  78     aux = it->funcs;
  79     if (aux == NULL || (aux->flags & ASN1_AFLG_REFCOUNT) == 0)
  80         return 0;
  81     lck = offset2ptr(*pval, aux->ref_offset);
  82     lock = offset2ptr(*pval, aux->ref_lock);
  83
  84     switch (op) {
  85     case 0:
  86         *lck = ret = 1;
  87         *lock = CRYPTO_THREAD_lock_new();
  88         if (*lock == NULL) {
  89             ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
  90             return -1;
  91         }
  92         break;
  93     case 1:
  94         if (!CRYPTO_UP_REF(lck, &ret, *lock))
  95             return -1;
  96         break;
  97     case -1:
  98         if (!CRYPTO_DOWN_REF(lck, &ret, *lock))
  99             return -1;  /* failed */
 100 #ifdef REF_PRINT
 101         fprintf(stderr, "%p:%4d:%s\n", (void*)it, ret, it->sname);
 102 #endif
 103         REF_ASSERT_ISNT(ret < 0);
 104         if (ret == 0) {
 105             CRYPTO_THREAD_lock_free(*lock);
 106             *lock = NULL;
 107         }
 108         break;
 109     }
 110
 111     return ret;
 112 }
 113
 114 static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
 115 {
 116     const ASN1_AUX *aux;
 117
 118     if (pval == NULL || *pval == NULL)
 119         return NULL;
 120     aux = it->funcs;
 121     if (aux == NULL || (aux->flags & ASN1_AFLG_ENCODING) == 0)
 122         return NULL;
 123     return offset2ptr(*pval, aux->enc_offset);
 124 }
 125
 126 static const ASN1_ENCODING *asn1_get_const_enc_ptr(const ASN1_VALUE **pval,
 127                                                    const ASN1_ITEM *it)
 128 {
 129     const ASN1_AUX *aux;
 130
 131     if (pval == NULL || *pval == NULL)
 132         return NULL;
 133     aux = it->funcs;
 134     if (aux == NULL || (aux->flags & ASN1_AFLG_ENCODING) == 0)
 135         return NULL;
 136     return offset2ptr(*pval, aux->enc_offset);
 137 }
 138
 139 void ossl_asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
 140 {
 141     ASN1_ENCODING *enc = asn1_get_enc_ptr(pval, it);
 142
 143     if (enc != NULL) {
 144         enc->enc = NULL;
 145         enc->len = 0;
 146         enc->modified = 1;
 147     }
 148 }
 149
 150 void ossl_asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
 151 {
 152     ASN1_ENCODING *enc = asn1_get_enc_ptr(pval, it);
 153
 154     if (enc != NULL) {
 155         OPENSSL_free(enc->enc);
 156         enc->enc = NULL;
 157         enc->len = 0;
 158         enc->modified = 1;
 159     }
 160 }
 161
 162 int ossl_asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
 163                        const ASN1_ITEM *it)
 164 {
 165     ASN1_ENCODING *enc = asn1_get_enc_ptr(pval, it);
 166
 167     if (enc == NULL)
 168         return 1;
 169
 170     OPENSSL_free(enc->enc);
 171     if ((enc->enc = OPENSSL_malloc(inlen)) == NULL) {
 172         ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
 173         return 0;
 174     }
 175     memcpy(enc->enc, in, inlen);
 176     enc->len = inlen;
 177     enc->modified = 0;
 178
 179     return 1;
 180 }
 181
 182 int ossl_asn1_enc_restore(int *len, unsigned char **out, const ASN1_VALUE **pval,
 183                           const ASN1_ITEM *it)
 184 {
 185     const ASN1_ENCODING *enc = asn1_get_const_enc_ptr(pval, it);
 186
 187     if (enc == NULL || enc->modified)
 188         return 0;
 189     if (out) {
 190         memcpy(*out, enc->enc, enc->len);
 191         *out += enc->len;
 192     }
 193     if (len != NULL)
 194         *len = enc->len;
 195     return 1;
 196 }
 197
 198 /* Given an ASN1_TEMPLATE get a pointer to a field */
 199 ASN1_VALUE **ossl_asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
 200 {
 201     ASN1_VALUE **pvaltmp = offset2ptr(*pval, tt->offset);
 202
 203     /*
 204      * NOTE for BOOLEAN types the field is just a plain int so we can't
 205      * return int **, so settle for (int *).
 206      */
 207     return pvaltmp;
 208 }
 209
 210 /* Given an ASN1_TEMPLATE get a const pointer to a field */
 211 const ASN1_VALUE **ossl_asn1_get_const_field_ptr(const ASN1_VALUE **pval,
 212                                                  const ASN1_TEMPLATE *tt)
 213 {
 214     return offset2ptr(*pval, tt->offset);
 215 }
 216
 217 /*
 218  * Handle ANY DEFINED BY template, find the selector, look up the relevant
 219  * ASN1_TEMPLATE in the table and return it.
 220  */
 221
 222 const ASN1_TEMPLATE *ossl_asn1_do_adb(const ASN1_VALUE *val,
 223                                       const ASN1_TEMPLATE *tt,
 224                                       int nullerr)
 225 {
 226     const ASN1_ADB *adb;
 227     const ASN1_ADB_TABLE *atbl;
 228     long selector;
 229     const ASN1_VALUE **sfld;
 230     int i;
 231
 232     if ((tt->flags & ASN1_TFLG_ADB_MASK) == 0)
 233         return tt;
 234
 235     /* Else ANY DEFINED BY ... get the table */
 236     adb = ASN1_ADB_ptr(tt->item);
 237
 238     /* Get the selector field */
 239     sfld = offset2ptr(val, adb->offset);
 240
 241     /* Check if NULL */
 242     if (*sfld == NULL) {
 243         if (adb->null_tt == NULL)
 244             goto err;
 245         return adb->null_tt;
 246     }
 247
 248     /*
 249      * Convert type to a long: NB: don't check for NID_undef here because it
 250      * might be a legitimate value in the table
 251      */
 252     if ((tt->flags & ASN1_TFLG_ADB_OID) != 0)
 253         selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
 254     else
 255         selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
 256
 257     /* Let application callback translate value */
 258     if (adb->adb_cb != NULL && adb->adb_cb(&selector) == 0) {
 259         ERR_raise(ERR_LIB_ASN1, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 260         return NULL;
 261     }
 262
 263     /*
 264      * Try to find matching entry in table Maybe should check application
 265      * types first to allow application override? Might also be useful to
 266      * have a flag which indicates table is sorted and we can do a binary
 267      * search. For now stick to a linear search.
 268      */
 269
 270     for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
 271         if (atbl->value == selector)
 272             return &atbl->tt;
 273
 274     /* FIXME: need to search application table too */
 275
 276     /* No match, return default type */
 277     if (!adb->default_tt)
 278         goto err;
 279     return adb->default_tt;
 280
 281  err:
 282     /* FIXME: should log the value or OID of unsupported type */
 283     if (nullerr)
 284         ERR_raise(ERR_LIB_ASN1, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
 285     return NULL;
 286 }