crypto/ocsp/ocsp_vfy.c

   1 /* ocsp_vfy.c */
   2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
   3  * project 2000.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 #include <openssl/ocsp.h>
  60 #include <openssl/err.h>
  61
  62 static X509 *ocsp_find_signer(OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
  63                                 X509_STORE *st, unsigned long flags);
  64 static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id);
  65
  66 /* Verify a basic response message */
  67
  68 int OCSP_basic_verify(OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
  69                                 X509_STORE *st, unsigned long flags)
  70         {
  71         X509 *signer, *x;
  72         STACK_OF(X509) *chain = NULL;
  73         X509_STORE_CTX ctx;
  74         int i, ret = 0;
  75         signer = ocsp_find_signer(bs, certs, st, flags);
  76         if (!signer)
  77                 {
  78                 OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND);
  79                 goto end;
  80                 }
  81         if(!(flags & OCSP_NOSIGS))
  82                 {
  83                 EVP_PKEY *skey;
  84                 skey = X509_get_pubkey(signer);
  85                 ret = OCSP_BASICRESP_verify(bs, skey, 0);
  86                 EVP_PKEY_free(skey);
  87                 if(ret <= 0)
  88                         {
  89                         OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, OCSP_R_SIGNATURE_FAILURE);
  90                         goto end;
  91                         }
  92                 }
  93         if(!(flags & OCSP_NOVERIFY))
  94                 {
  95                 if(flags & OCSP_NOCHAIN)
  96                         X509_STORE_CTX_init(&ctx, st, signer, NULL);
  97                 else
  98                         X509_STORE_CTX_init(&ctx, st, signer, bs->certs);
  99
 100                 X509_STORE_CTX_set_purpose(&ctx, X509_PURPOSE_OCSP_HELPER);
 101                 ret = X509_verify_cert(&ctx);
 102                 chain = X509_STORE_CTX_get1_chain(&ctx);
 103                 X509_STORE_CTX_cleanup(&ctx);
 104                 if (ret <= 0)
 105                         {
 106                         i = X509_STORE_CTX_get_error(&ctx);
 107                         OCSPerr(OCSP_F_OCSP_BASIC_VERIFY,OCSP_R_CERTIFICATE_VERIFY_ERROR);
 108                         ERR_add_error_data(2, "Verify error:",
 109                                         X509_verify_cert_error_string(i));
 110                         goto end;
 111                         }
 112                 if(flags & OCSP_NOCHECKS)
 113                         {
 114                         ret = 1;
 115                         goto end;
 116                         }
 117                 /* At this point we have a valid certificate chain
 118                  * need to verify it against the OCSP criteria.
 119                  */
 120 #if 0
 121                 if(ocsp_check_issuer(bs, chain, flags))
 122                         {
 123                         ret = 1;
 124                         goto end;
 125                         }
 126 #endif
 127
 128                 /* Easy case: explicitly trusted. Get root CA and
 129                  * check for explicit trust
 130                  */
 131                 if(flags & OCSP_NOEXPLICIT) goto end;
 132
 133                 x = sk_X509_value(chain, sk_X509_num(chain) - 1);
 134                 if(X509_check_trust(x, NID_OCSP_sign, 0) != X509_TRUST_TRUSTED)
 135                         {
 136                         OCSPerr(OCSP_F_OCSP_BASIC_VERIFY,OCSP_R_ROOT_CA_NOT_TRUSTED);
 137                         goto end;
 138                         }
 139                 ret = 1;
 140                 }
 141
 142
 143
 144         end:
 145         if(chain) sk_X509_pop_free(chain, X509_free);
 146         return 1;
 147         }
 148
 149
 150 static X509 *ocsp_find_signer(OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
 151                                 X509_STORE *st, unsigned long flags)
 152         {
 153         X509 *signer;
 154         OCSP_RESPID *rid = bs->tbsResponseData->responderId;
 155         if ((signer = ocsp_find_signer_sk(certs, rid)))
 156                 return signer;
 157         if(!(flags & OCSP_NOINTERN) &&
 158             (signer = ocsp_find_signer_sk(bs->certs, rid)))
 159                 return signer;
 160         /* Maybe lookup from store if by subject name */
 161
 162         return NULL;
 163         }
 164
 165
 166 static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id)
 167         {
 168         int i;
 169         unsigned char tmphash[SHA_DIGEST_LENGTH], *keyhash;
 170         ASN1_BIT_STRING *key;
 171         EVP_MD_CTX ctx;
 172         X509 *x;
 173
 174         /* Easy if lookup by name */
 175         if(id->type == V_OCSP_RESPID_NAME)
 176                 return X509_find_by_subject(certs, id->value.byName);
 177
 178         /* Lookup by key hash */
 179
 180         /* If key hash isn't SHA1 length then forget it */
 181         if(id->value.byKey->length != SHA_DIGEST_LENGTH) return NULL;
 182         keyhash = id->value.byKey->data;
 183         /* Calculate hash of each key and compare */
 184         for(i = 0; i < sk_X509_num(certs); i++)
 185                 {
 186                 x = sk_X509_value(certs, i);
 187                 key = x->cert_info->key->public_key;
 188                 EVP_DigestInit(&ctx,EVP_sha1());
 189                 EVP_DigestUpdate(&ctx,key->data, key->length);
 190                 EVP_DigestFinal(&ctx,tmphash,NULL);
 191                 if(!memcmp(keyhash, tmphash, SHA_DIGEST_LENGTH))
 192                         return x;
 193                 }
 194         return NULL;
 195         }
 196
 197