/* ocsp_vfy.c */
/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
* project 2000.
*/
/* ====================================================================
* Copyright (c) 2000-2004 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include <openssl/ocsp.h>
#include <openssl/err.h>
#include <string.h>
static int ocsp_find_signer(X509 **psigner, OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
X509_STORE *st, unsigned long flags);
static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id);
static int ocsp_check_issuer(OCSP_BASICRESP *bs, STACK_OF(X509) *chain, unsigned long flags);
static int ocsp_check_ids(STACK_OF(OCSP_SINGLERESP) *sresp, OCSP_CERTID **ret);
static int ocsp_match_issuerid(X509 *cert, OCSP_CERTID *cid, STACK_OF(OCSP_SINGLERESP) *sresp);
static int ocsp_check_delegated(X509 *x, int flags);
static int ocsp_req_find_signer(X509 **psigner, OCSP_REQUEST *req, X509_NAME *nm, STACK_OF(X509) *certs,
X509_STORE *st, unsigned long flags);
/* Verify a basic response message */
int OCSP_basic_verify(OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
X509_STORE *st, unsigned long flags)
{
X509 *signer, *x;
STACK_OF(X509) *chain = NULL;
X509_STORE_CTX ctx;
int i, ret = 0;
ret = ocsp_find_signer(&signer, bs, certs, st, flags);
if (!ret)
{
OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND);
goto end;
}
if ((ret == 2) && (flags & OCSP_TRUSTOTHER))
flags |= OCSP_NOVERIFY;
if (!(flags & OCSP_NOSIGS))
{
EVP_PKEY *skey;
skey = X509_get_pubkey(signer);
ret = OCSP_BASICRESP_verify(bs, skey, 0);
EVP_PKEY_free(skey);
if(ret <= 0)
{
OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, OCSP_R_SIGNATURE_FAILURE);
goto end;
}
}
if (!(flags & OCSP_NOVERIFY))
{
int init_res;
if(flags & OCSP_NOCHAIN)
init_res = X509_STORE_CTX_init(&ctx, st, signer, NULL);
else
init_res = X509_STORE_CTX_init(&ctx, st, signer, bs->certs);
if(!init_res)
{
OCSPerr(OCSP_F_OCSP_BASIC_VERIFY,ERR_R_X509_LIB);
goto end;
}
X509_STORE_CTX_set_purpose(&ctx, X509_PURPOSE_OCSP_HELPER);
ret = X509_verify_cert(&ctx);
chain = X509_STORE_CTX_get1_chain(&ctx);
X509_STORE_CTX_cleanup(&ctx);
if (ret <= 0)
{
i = X509_STORE_CTX_get_error(&ctx);
OCSPerr(OCSP_F_OCSP_BASIC_VERIFY,OCSP_R_CERTIFICATE_VERIFY_ERROR);
ERR_add_error_data(2, "Verify error:",
X509_verify_cert_error_string(i));
goto end;
}
if(flags & OCSP_NOCHECKS)
{
ret = 1;
goto end;
}
/* At this point we have a valid certificate chain
* need to verify it against the OCSP issuer criteria.
*/
ret = ocsp_check_issuer(bs, chain, flags);
/* If fatal error or valid match then finish */
if (ret != 0) goto end;
/* Easy case: explicitly trusted. Get root CA and
* check for explicit trust
*/
if(flags & OCSP_NOEXPLICIT) goto end;
x = sk_X509_value(chain, sk_X509_num(chain) - 1);
if(X509_check_trust(x, NID_OCSP_sign, 0) != X509_TRUST_TRUSTED)
{
OCSPerr(OCSP_F_OCSP_BASIC_VERIFY,OCSP_R_ROOT_CA_NOT_TRUSTED);
goto end;
}
ret = 1;
}
end:
if(chain) sk_X509_pop_free(chain, X509_free);
return ret;
}
static int ocsp_find_signer(X509 **psigner, OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
X509_STORE *st, unsigned long flags)
{
X509 *signer;
OCSP_RESPID *rid = bs->tbsResponseData->responderId;
if ((signer = ocsp_find_signer_sk(certs, rid)))
{
*psigner = signer;
return 2;
}
if(!(flags & OCSP_NOINTERN) &&
(signer = ocsp_find_signer_sk(bs->certs, rid)))
{
*psigner = signer;
return 1;
}
/* Maybe lookup from store if by subject name */
*psigner = NULL;
return 0;
}
static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id)
{
int i;
unsigned char tmphash[SHA_DIGEST_LENGTH], *keyhash;
X509 *x;
/* Easy if lookup by name */
if (id->type == V_OCSP_RESPID_NAME)
return X509_find_by_subject(certs, id->value.byName);
/* Lookup by key hash */
/* If key hash isn't SHA1 length then forget it */
if (id->value.byKey->length != SHA_DIGEST_LENGTH) return NULL;
keyhash = id->value.byKey->data;
/* Calculate hash of each key and compare */
for (i = 0; i < sk_X509_num(certs); i++)
{
x = sk_X509_value(certs, i);
X509_pubkey_digest(x, EVP_sha1(), tmphash, NULL);
if(!memcmp(keyhash, tmphash, SHA_DIGEST_LENGTH))
return x;
}
return NULL;
}
static int ocsp_check_issuer(OCSP_BASICRESP *bs, STACK_OF(X509) *chain, unsigned long flags)
{
STACK_OF(OCSP_SINGLERESP) *sresp;
X509 *signer, *sca;
OCSP_CERTID *caid = NULL;
int i;
sresp = bs->tbsResponseData->responses;
if (sk_X509_num(chain) <= 0)
{
OCSPerr(OCSP_F_OCSP_CHECK_ISSUER, OCSP_R_NO_CERTIFICATES_IN_CHAIN);
return -1;
}
/* See if the issuer IDs match. */
i = ocsp_check_ids(sresp, &caid);
/* If ID mismatch or other error then return */
if (i <= 0) return i;
signer = sk_X509_value(chain, 0);
/* Check to see if OCSP responder CA matches request CA */
if (sk_X509_num(chain) > 1)
{
sca = sk_X509_value(chain, 1);
i = ocsp_match_issuerid(sca, caid, sresp);
if (i < 0) return i;
if (i)
{
/* We have a match, if extensions OK then success */
if (ocsp_check_delegated(signer, flags)) return 1;
return 0;
}
}
/* Otherwise check if OCSP request signed directly by request CA */
return ocsp_match_issuerid(signer, caid, sresp);
}
/* Check the issuer certificate IDs for equality. If there is a mismatch with the same
* algorithm then there's no point trying to match any certificates against the issuer.
* If the issuer IDs all match then we just need to check equality against one of them.
*/
static int ocsp_check_ids(STACK_OF(OCSP_SINGLERESP) *sresp, OCSP_CERTID **ret)
{
OCSP_CERTID *tmpid, *cid;
int i, idcount;
idcount = sk_OCSP_SINGLERESP_num(sresp);
if (idcount <= 0)
{
OCSPerr(OCSP_F_OCSP_CHECK_IDS, OCSP_R_RESPONSE_CONTAINS_NO_REVOCATION_DATA);
return -1;
}
cid = sk_OCSP_SINGLERESP_value(sresp, 0)->certId;
*ret = NULL;
for (i = 1; i < idcount; i++)
{
tmpid = sk_OCSP_SINGLERESP_value(sresp, i)->certId;
/* Check to see if IDs match */
if (OCSP_id_issuer_cmp(cid, tmpid))
{
/* If algoritm mismatch let caller deal with it */
if (OBJ_cmp(tmpid->hashAlgorithm->algorithm,
cid->hashAlgorithm->algorithm))
return 2;
/* Else mismatch */
return 0;
}
}
/* All IDs match: only need to check one ID */
*ret = cid;
return 1;
}
static int ocsp_match_issuerid(X509 *cert, OCSP_CERTID *cid,
STACK_OF(OCSP_SINGLERESP) *sresp)
{
/* If only one ID to match then do it */
if(cid)
{
const EVP_MD *dgst;
X509_NAME *iname;
int mdlen;
unsigned char md[EVP_MAX_MD_SIZE];
if (!(dgst = EVP_get_digestbyobj(cid->hashAlgorithm->algorithm)))
{
OCSPerr(OCSP_F_OCSP_MATCH_ISSUERID, OCSP_R_UNKNOWN_MESSAGE_DIGEST);
return -1;
}
mdlen = EVP_MD_size(dgst);
if ((cid->issuerNameHash->length != mdlen) ||
(cid->issuerKeyHash->length != mdlen))
return 0;
iname = X509_get_subject_name(cert);
if (!X509_NAME_digest(iname, dgst, md, NULL))
return -1;
if (memcmp(md, cid->issuerNameHash->data, mdlen))
return 0;
X509_pubkey_digest(cert, EVP_sha1(), md, NULL);
if (memcmp(md, cid->issuerKeyHash->data, mdlen))
return 0;
return 1;
}
else
{
/* We have to match the whole lot */
int i, ret;
OCSP_CERTID *tmpid;
for (i = 0; i < sk_OCSP_SINGLERESP_num(sresp); i++)
{
tmpid = sk_OCSP_SINGLERESP_value(sresp, i)->certId;
ret = ocsp_match_issuerid(cert, tmpid, NULL);
if (ret <= 0) return ret;
}
return 1;
}
}
static int ocsp_check_delegated(X509 *x, int flags)
{
X509_check_purpose(x, -1, 0);
if ((x->ex_flags & EXFLAG_XKUSAGE) &&
(x->ex_xkusage & XKU_OCSP_SIGN))
return 1;
OCSPerr(OCSP_F_OCSP_CHECK_DELEGATED, OCSP_R_MISSING_OCSPSIGNING_USAGE);
return 0;
}
/* Verify an OCSP request. This is fortunately much easier than OCSP
* response verify. Just find the signers certificate and verify it
* against a given trust value.
*/
int OCSP_request_verify(OCSP_REQUEST *req, STACK_OF(X509) *certs, X509_STORE *store, unsigned long flags)
{
X509 *signer;
X509_NAME *nm;
GENERAL_NAME *gen;
int ret;
X509_STORE_CTX ctx;
if (!req->optionalSignature)
{
OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY, OCSP_R_REQUEST_NOT_SIGNED);
return 0;
}
gen = req->tbsRequest->requestorName;
if (!gen || gen->type != GEN_DIRNAME)
{
OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY, OCSP_R_UNSUPPORTED_REQUESTORNAME_TYPE);
return 0;
}
nm = gen->d.directoryName;
ret = ocsp_req_find_signer(&signer, req, nm, certs, store, flags);
if (ret <= 0)
{
OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY, OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND);
return 0;
}
if ((ret == 2) && (flags & OCSP_TRUSTOTHER))
flags |= OCSP_NOVERIFY;
if (!(flags & OCSP_NOSIGS))
{
EVP_PKEY *skey;
skey = X509_get_pubkey(signer);
ret = OCSP_REQUEST_verify(req, skey);
EVP_PKEY_free(skey);
if(ret <= 0)
{
OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY, OCSP_R_SIGNATURE_FAILURE);
return 0;
}
}
if (!(flags & OCSP_NOVERIFY))
{
int init_res;
if(flags & OCSP_NOCHAIN)
init_res = X509_STORE_CTX_init(&ctx, store, signer, NULL);
else
init_res = X509_STORE_CTX_init(&ctx, store, signer,
req->optionalSignature->certs);
if(!init_res)
{
OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY,ERR_R_X509_LIB);
return 0;
}
X509_STORE_CTX_set_purpose(&ctx, X509_PURPOSE_OCSP_HELPER);
X509_STORE_CTX_set_trust(&ctx, X509_TRUST_OCSP_REQUEST);
ret = X509_verify_cert(&ctx);
X509_STORE_CTX_cleanup(&ctx);
if (ret <= 0)
{
ret = X509_STORE_CTX_get_error(&ctx);
OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY,OCSP_R_CERTIFICATE_VERIFY_ERROR);
ERR_add_error_data(2, "Verify error:",
X509_verify_cert_error_string(ret));
return 0;
}
}
return 1;
}
static int ocsp_req_find_signer(X509 **psigner, OCSP_REQUEST *req, X509_NAME *nm, STACK_OF(X509) *certs,
X509_STORE *st, unsigned long flags)
{
X509 *signer;
if(!(flags & OCSP_NOINTERN))
{
signer = X509_find_by_subject(req->optionalSignature->certs, nm);
*psigner = signer;
return 1;
}
signer = X509_find_by_subject(certs, nm);
if (signer)
{
*psigner = signer;
return 2;
}
return 0;
}
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