2 * Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved.
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
10 #include <openssl/ocsp.h>
11 #include "ocsp_local.h"
12 #include <openssl/err.h>
15 static int ocsp_find_signer(X509 **psigner, OCSP_BASICRESP *bs,
16 STACK_OF(X509) *certs, unsigned long flags);
17 static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id);
18 static int ocsp_check_issuer(OCSP_BASICRESP *bs, STACK_OF(X509) *chain);
19 static int ocsp_check_ids(STACK_OF(OCSP_SINGLERESP) *sresp,
21 static int ocsp_match_issuerid(X509 *cert, OCSP_CERTID *cid,
22 STACK_OF(OCSP_SINGLERESP) *sresp);
23 static int ocsp_check_delegated(X509 *x);
24 static int ocsp_req_find_signer(X509 **psigner, OCSP_REQUEST *req,
25 const X509_NAME *nm, STACK_OF(X509) *certs,
28 /* Returns 1 on success, 0 on failure, or -1 on fatal error */
29 static int ocsp_verify_signer(X509 *signer, int response,
30 X509_STORE *st, unsigned long flags,
31 STACK_OF(X509) *untrusted, STACK_OF(X509) **chain)
33 X509_STORE_CTX *ctx = X509_STORE_CTX_new();
34 X509_VERIFY_PARAM *vp;
38 ERR_raise(ERR_LIB_OCSP, ERR_R_MALLOC_FAILURE);
41 if (!X509_STORE_CTX_init(ctx, st, signer, untrusted)) {
42 ERR_raise(ERR_LIB_OCSP, ERR_R_X509_LIB);
45 if ((vp = X509_STORE_CTX_get0_param(ctx)) == NULL)
47 if ((flags & OCSP_PARTIAL_CHAIN) != 0)
48 X509_VERIFY_PARAM_set_flags(vp, X509_V_FLAG_PARTIAL_CHAIN);
50 && X509_get_ext_by_NID(signer, NID_id_pkix_OCSP_noCheck, -1) >= 0)
52 * Locally disable revocation status checking for OCSP responder cert.
53 * Done here for CRLs; TODO should be done also for OCSP-based checks.
55 X509_VERIFY_PARAM_clear_flags(vp, X509_V_FLAG_CRL_CHECK);
56 X509_STORE_CTX_set_purpose(ctx, X509_PURPOSE_OCSP_HELPER);
57 X509_STORE_CTX_set_trust(ctx, X509_TRUST_OCSP_REQUEST);
58 /* TODO: why is X509_TRUST_OCSP_REQUEST set? Seems to get ignored. */
60 ret = X509_verify_cert(ctx);
62 ret = X509_STORE_CTX_get_error(ctx);
63 ERR_raise_data(ERR_LIB_OCSP, OCSP_R_CERTIFICATE_VERIFY_ERROR,
64 "Verify error: %s", X509_verify_cert_error_string(ret));
68 *chain = X509_STORE_CTX_get1_chain(ctx);
71 X509_STORE_CTX_free(ctx);
75 static int ocsp_verify(OCSP_REQUEST *req, OCSP_BASICRESP *bs,
76 X509 *signer, unsigned long flags)
81 if ((flags & OCSP_NOSIGS) == 0) {
82 if ((skey = X509_get0_pubkey(signer)) == NULL) {
83 ERR_raise(ERR_LIB_OCSP, OCSP_R_NO_SIGNER_KEY);
87 ret = OCSP_REQUEST_verify(req, skey);
89 ret = OCSP_BASICRESP_verify(bs, skey);
91 ERR_raise(ERR_LIB_OCSP, OCSP_R_SIGNATURE_FAILURE);
96 /* Verify a basic response message */
97 int OCSP_basic_verify(OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
98 X509_STORE *st, unsigned long flags)
101 STACK_OF(X509) *chain = NULL;
102 STACK_OF(X509) *untrusted = NULL;
103 int ret = ocsp_find_signer(&signer, bs, certs, flags);
106 ERR_raise(ERR_LIB_OCSP, OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND);
109 if ((ret == 2) && (flags & OCSP_TRUSTOTHER) != 0)
110 flags |= OCSP_NOVERIFY;
112 if ((ret = ocsp_verify(NULL, bs, signer, flags)) <= 0)
114 if ((flags & OCSP_NOVERIFY) == 0) {
116 if ((flags & OCSP_NOCHAIN) == 0) {
117 if ((untrusted = sk_X509_dup(bs->certs)) == NULL)
119 if (!X509_add_certs(untrusted, certs, X509_ADD_FLAG_DEFAULT))
121 } else if (certs != NULL) {
124 untrusted = bs->certs;
126 ret = ocsp_verify_signer(signer, 1, st, flags, untrusted, &chain);
129 if ((flags & OCSP_NOCHECKS) != 0) {
134 * At this point we have a valid certificate chain need to verify it
135 * against the OCSP issuer criteria.
137 ret = ocsp_check_issuer(bs, chain);
139 /* If fatal error or valid match then finish */
144 * Easy case: explicitly trusted. Get root CA and check for explicit
147 if ((flags & OCSP_NOEXPLICIT) != 0)
150 x = sk_X509_value(chain, sk_X509_num(chain) - 1);
151 if (X509_check_trust(x, NID_OCSP_sign, 0) != X509_TRUST_TRUSTED) {
152 ERR_raise(ERR_LIB_OCSP, OCSP_R_ROOT_CA_NOT_TRUSTED);
160 sk_X509_pop_free(chain, X509_free);
161 sk_X509_free(untrusted);
165 int OCSP_resp_get0_signer(OCSP_BASICRESP *bs, X509 **signer,
166 STACK_OF(X509) *extra_certs)
168 return ocsp_find_signer(signer, bs, extra_certs, 0) > 0;
171 static int ocsp_find_signer(X509 **psigner, OCSP_BASICRESP *bs,
172 STACK_OF(X509) *certs, unsigned long flags)
175 OCSP_RESPID *rid = &bs->tbsResponseData.responderId;
177 if ((signer = ocsp_find_signer_sk(certs, rid)) != NULL) {
181 if ((flags & OCSP_NOINTERN) == 0 &&
182 (signer = ocsp_find_signer_sk(bs->certs, rid))) {
186 /* Maybe lookup from store if by subject name */
192 static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id)
195 unsigned char tmphash[SHA_DIGEST_LENGTH], *keyhash;
198 /* Easy if lookup by name */
199 if (id->type == V_OCSP_RESPID_NAME)
200 return X509_find_by_subject(certs, id->value.byName);
202 /* Lookup by key hash */
204 /* If key hash isn't SHA1 length then forget it */
205 if (id->value.byKey->length != SHA_DIGEST_LENGTH)
207 keyhash = id->value.byKey->data;
208 /* Calculate hash of each key and compare */
209 for (i = 0; i < sk_X509_num(certs); i++) {
210 x = sk_X509_value(certs, i);
211 if (!X509_pubkey_digest(x, EVP_sha1(), tmphash, NULL))
213 if (memcmp(keyhash, tmphash, SHA_DIGEST_LENGTH) == 0)
219 static int ocsp_check_issuer(OCSP_BASICRESP *bs, STACK_OF(X509) *chain)
221 STACK_OF(OCSP_SINGLERESP) *sresp = bs->tbsResponseData.responses;
223 OCSP_CERTID *caid = NULL;
226 if (sk_X509_num(chain) <= 0) {
227 ERR_raise(ERR_LIB_OCSP, OCSP_R_NO_CERTIFICATES_IN_CHAIN);
231 /* See if the issuer IDs match. */
232 ret = ocsp_check_ids(sresp, &caid);
234 /* If ID mismatch or other error then return */
238 signer = sk_X509_value(chain, 0);
239 /* Check to see if OCSP responder CA matches request CA */
240 if (sk_X509_num(chain) > 1) {
241 sca = sk_X509_value(chain, 1);
242 ret = ocsp_match_issuerid(sca, caid, sresp);
246 /* We have a match, if extensions OK then success */
247 if (ocsp_check_delegated(signer))
253 /* Otherwise check if OCSP request signed directly by request CA */
254 return ocsp_match_issuerid(signer, caid, sresp);
258 * Check the issuer certificate IDs for equality. If there is a mismatch with
259 * the same algorithm then there's no point trying to match any certificates
260 * against the issuer. If the issuer IDs all match then we just need to check
261 * equality against one of them.
264 static int ocsp_check_ids(STACK_OF(OCSP_SINGLERESP) *sresp, OCSP_CERTID **ret)
266 OCSP_CERTID *tmpid, *cid;
269 idcount = sk_OCSP_SINGLERESP_num(sresp);
271 ERR_raise(ERR_LIB_OCSP, OCSP_R_RESPONSE_CONTAINS_NO_REVOCATION_DATA);
275 cid = sk_OCSP_SINGLERESP_value(sresp, 0)->certId;
278 for (i = 1; i < idcount; i++) {
279 tmpid = sk_OCSP_SINGLERESP_value(sresp, i)->certId;
280 /* Check to see if IDs match */
281 if (OCSP_id_issuer_cmp(cid, tmpid)) {
282 /* If algorithm mismatch let caller deal with it */
283 if (OBJ_cmp(tmpid->hashAlgorithm.algorithm,
284 cid->hashAlgorithm.algorithm))
291 /* All IDs match: only need to check one ID */
297 * Match the certificate issuer ID.
298 * Returns -1 on fatal error, 0 if there is no match and 1 if there is a match.
300 static int ocsp_match_issuerid(X509 *cert, OCSP_CERTID *cid,
301 STACK_OF(OCSP_SINGLERESP) *sresp)
303 /* If only one ID to match then do it */
305 const EVP_MD *dgst = EVP_get_digestbyobj(cid->hashAlgorithm.algorithm);
306 const X509_NAME *iname;
308 unsigned char md[EVP_MAX_MD_SIZE];
311 ERR_raise(ERR_LIB_OCSP, OCSP_R_UNKNOWN_MESSAGE_DIGEST);
315 mdlen = EVP_MD_size(dgst);
317 ERR_raise(ERR_LIB_OCSP, OCSP_R_DIGEST_SIZE_ERR);
320 if (cid->issuerNameHash.length != mdlen ||
321 cid->issuerKeyHash.length != mdlen)
323 iname = X509_get_subject_name(cert);
324 if (!X509_NAME_digest(iname, dgst, md, NULL)) {
325 ERR_raise(ERR_LIB_OCSP, OCSP_R_DIGEST_NAME_ERR);
328 if (memcmp(md, cid->issuerNameHash.data, mdlen) != 0)
330 if (!X509_pubkey_digest(cert, dgst, md, NULL)) {
331 ERR_raise(ERR_LIB_OCSP, OCSP_R_DIGEST_ERR);
334 if (memcmp(md, cid->issuerKeyHash.data, mdlen) != 0)
337 /* We have to match the whole lot */
341 for (i = 0; i < sk_OCSP_SINGLERESP_num(sresp); i++) {
342 tmpid = sk_OCSP_SINGLERESP_value(sresp, i)->certId;
343 ret = ocsp_match_issuerid(cert, tmpid, NULL);
351 static int ocsp_check_delegated(X509 *x)
353 if ((X509_get_extension_flags(x) & EXFLAG_XKUSAGE)
354 && (X509_get_extended_key_usage(x) & XKU_OCSP_SIGN))
356 ERR_raise(ERR_LIB_OCSP, OCSP_R_MISSING_OCSPSIGNING_USAGE);
361 * Verify an OCSP request. This is much easier than OCSP response verify.
362 * Just find the signer's certificate and verify it against a given trust value.
363 * Returns 1 on success, 0 on failure and on fatal error.
365 int OCSP_request_verify(OCSP_REQUEST *req, STACK_OF(X509) *certs,
366 X509_STORE *store, unsigned long flags)
373 if (!req->optionalSignature) {
374 ERR_raise(ERR_LIB_OCSP, OCSP_R_REQUEST_NOT_SIGNED);
377 gen = req->tbsRequest.requestorName;
378 if (!gen || gen->type != GEN_DIRNAME) {
379 ERR_raise(ERR_LIB_OCSP, OCSP_R_UNSUPPORTED_REQUESTORNAME_TYPE);
380 return 0; /* not returning -1 here for backward compatibility*/
382 nm = gen->d.directoryName;
383 ret = ocsp_req_find_signer(&signer, req, nm, certs, flags);
385 ERR_raise(ERR_LIB_OCSP, OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND);
386 return 0; /* not returning -1 here for backward compatibility*/
388 if ((ret == 2) && (flags & OCSP_TRUSTOTHER) != 0)
389 flags |= OCSP_NOVERIFY;
391 if ((ret = ocsp_verify(req, NULL, signer, flags)) <= 0)
392 return 0; /* not returning 'ret' here for backward compatibility*/
393 if ((flags & OCSP_NOVERIFY) != 0)
395 return ocsp_verify_signer(signer, 0, store, flags,
396 (flags & OCSP_NOCHAIN) != 0 ?
397 NULL : req->optionalSignature->certs, NULL) > 0;
398 /* using '> 0' here to avoid breaking backward compatibility returning -1 */
401 static int ocsp_req_find_signer(X509 **psigner, OCSP_REQUEST *req,
402 const X509_NAME *nm, STACK_OF(X509) *certs,
407 if ((flags & OCSP_NOINTERN) == 0) {
408 signer = X509_find_by_subject(req->optionalSignature->certs, nm);
409 if (signer != NULL) {
415 if ((signer = X509_find_by_subject(certs, nm)) != NULL) {