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Make OCSP response verification more flexible.
[thirdparty/openssl.git] / crypto / ocsp / ocsp_vfy.c
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9b4dc830 1/* ocsp_vfy.c */
0f113f3e
MC
2/*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
4 * 2000.
9b4dc830
DSH
5 */
6/* ====================================================================
91180d45 7 * Copyright (c) 2000-2004 The OpenSSL Project. All rights reserved.
9b4dc830
DSH
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
0f113f3e 14 * notice, this list of conditions and the following disclaimer.
9b4dc830
DSH
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#include <openssl/ocsp.h>
6ef869d7 61#include "ocsp_lcl.h"
9b4dc830 62#include <openssl/err.h>
3ebac273 63#include <string.h>
9b4dc830 64
0f113f3e
MC
65static int ocsp_find_signer(X509 **psigner, OCSP_BASICRESP *bs,
66 STACK_OF(X509) *certs, X509_STORE *st,
67 unsigned long flags);
9b4dc830 68static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id);
0f113f3e
MC
69static int ocsp_check_issuer(OCSP_BASICRESP *bs, STACK_OF(X509) *chain,
70 unsigned long flags);
71static int ocsp_check_ids(STACK_OF(OCSP_SINGLERESP) *sresp,
72 OCSP_CERTID **ret);
73static int ocsp_match_issuerid(X509 *cert, OCSP_CERTID *cid,
74 STACK_OF(OCSP_SINGLERESP) *sresp);
e8af92fc 75static int ocsp_check_delegated(X509 *x, int flags);
0f113f3e
MC
76static int ocsp_req_find_signer(X509 **psigner, OCSP_REQUEST *req,
77 X509_NAME *nm, STACK_OF(X509) *certs,
78 X509_STORE *st, unsigned long flags);
9b4dc830
DSH
79
80/* Verify a basic response message */
81
82int OCSP_basic_verify(OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
0f113f3e
MC
83 X509_STORE *st, unsigned long flags)
84{
85 X509 *signer, *x;
86 STACK_OF(X509) *chain = NULL;
4ca5efc2 87 STACK_OF(X509) *untrusted = NULL;
0f113f3e
MC
88 X509_STORE_CTX ctx;
89 int i, ret = 0;
90 ret = ocsp_find_signer(&signer, bs, certs, st, flags);
91 if (!ret) {
92 OCSPerr(OCSP_F_OCSP_BASIC_VERIFY,
93 OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND);
94 goto end;
95 }
96 if ((ret == 2) && (flags & OCSP_TRUSTOTHER))
97 flags |= OCSP_NOVERIFY;
98 if (!(flags & OCSP_NOSIGS)) {
99 EVP_PKEY *skey;
100 skey = X509_get_pubkey(signer);
101 if (skey) {
102 ret = OCSP_BASICRESP_verify(bs, skey, 0);
103 EVP_PKEY_free(skey);
104 }
105 if (!skey || ret <= 0) {
106 OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, OCSP_R_SIGNATURE_FAILURE);
107 goto end;
108 }
109 }
110 if (!(flags & OCSP_NOVERIFY)) {
111 int init_res;
4ca5efc2
DSH
112 if (flags & OCSP_NOCHAIN) {
113 untrusted = NULL;
114 } else if (bs->certs && certs) {
115 untrusted = sk_X509_dup(bs->certs);
116 for (i = 0; i < sk_X509_num(certs); i++) {
117 if (!sk_X509_push(untrusted, sk_X509_value(certs, i))) {
118 OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, ERR_R_MALLOC_FAILURE);
119 goto end;
120 }
121 }
122 } else {
123 untrusted = bs->certs;
124 }
125 init_res = X509_STORE_CTX_init(&ctx, st, signer, untrusted);
0f113f3e
MC
126 if (!init_res) {
127 ret = -1;
128 OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, ERR_R_X509_LIB);
129 goto end;
130 }
9b4dc830 131
0f113f3e
MC
132 X509_STORE_CTX_set_purpose(&ctx, X509_PURPOSE_OCSP_HELPER);
133 ret = X509_verify_cert(&ctx);
134 chain = X509_STORE_CTX_get1_chain(&ctx);
135 X509_STORE_CTX_cleanup(&ctx);
136 if (ret <= 0) {
137 i = X509_STORE_CTX_get_error(&ctx);
138 OCSPerr(OCSP_F_OCSP_BASIC_VERIFY,
139 OCSP_R_CERTIFICATE_VERIFY_ERROR);
140 ERR_add_error_data(2, "Verify error:",
141 X509_verify_cert_error_string(i));
142 goto end;
143 }
144 if (flags & OCSP_NOCHECKS) {
145 ret = 1;
146 goto end;
147 }
148 /*
149 * At this point we have a valid certificate chain need to verify it
150 * against the OCSP issuer criteria.
151 */
152 ret = ocsp_check_issuer(bs, chain, flags);
153
154 /* If fatal error or valid match then finish */
155 if (ret != 0)
156 goto end;
157
158 /*
159 * Easy case: explicitly trusted. Get root CA and check for explicit
160 * trust
161 */
162 if (flags & OCSP_NOEXPLICIT)
163 goto end;
164
165 x = sk_X509_value(chain, sk_X509_num(chain) - 1);
166 if (X509_check_trust(x, NID_OCSP_sign, 0) != X509_TRUST_TRUSTED) {
167 OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, OCSP_R_ROOT_CA_NOT_TRUSTED);
168 goto end;
169 }
170 ret = 1;
171 }
172
173 end:
174 if (chain)
175 sk_X509_pop_free(chain, X509_free);
4ca5efc2
DSH
176 if (bs->certs && certs)
177 sk_X509_free(untrusted);
0f113f3e
MC
178 return ret;
179}
180
181static int ocsp_find_signer(X509 **psigner, OCSP_BASICRESP *bs,
182 STACK_OF(X509) *certs, X509_STORE *st,
183 unsigned long flags)
184{
185 X509 *signer;
186 OCSP_RESPID *rid = bs->tbsResponseData->responderId;
187 if ((signer = ocsp_find_signer_sk(certs, rid))) {
188 *psigner = signer;
189 return 2;
190 }
191 if (!(flags & OCSP_NOINTERN) &&
192 (signer = ocsp_find_signer_sk(bs->certs, rid))) {
193 *psigner = signer;
194 return 1;
195 }
196 /* Maybe lookup from store if by subject name */
197
198 *psigner = NULL;
199 return 0;
200}
9b4dc830
DSH
201
202static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id)
0f113f3e
MC
203{
204 int i;
205 unsigned char tmphash[SHA_DIGEST_LENGTH], *keyhash;
206 X509 *x;
207
208 /* Easy if lookup by name */
209 if (id->type == V_OCSP_RESPID_NAME)
210 return X509_find_by_subject(certs, id->value.byName);
211
212 /* Lookup by key hash */
213
214 /* If key hash isn't SHA1 length then forget it */
215 if (id->value.byKey->length != SHA_DIGEST_LENGTH)
216 return NULL;
217 keyhash = id->value.byKey->data;
218 /* Calculate hash of each key and compare */
219 for (i = 0; i < sk_X509_num(certs); i++) {
220 x = sk_X509_value(certs, i);
221 X509_pubkey_digest(x, EVP_sha1(), tmphash, NULL);
222 if (!memcmp(keyhash, tmphash, SHA_DIGEST_LENGTH))
223 return x;
224 }
225 return NULL;
226}
227
228static int ocsp_check_issuer(OCSP_BASICRESP *bs, STACK_OF(X509) *chain,
229 unsigned long flags)
230{
231 STACK_OF(OCSP_SINGLERESP) *sresp;
232 X509 *signer, *sca;
233 OCSP_CERTID *caid = NULL;
234 int i;
235 sresp = bs->tbsResponseData->responses;
236
237 if (sk_X509_num(chain) <= 0) {
238 OCSPerr(OCSP_F_OCSP_CHECK_ISSUER, OCSP_R_NO_CERTIFICATES_IN_CHAIN);
239 return -1;
240 }
241
242 /* See if the issuer IDs match. */
243 i = ocsp_check_ids(sresp, &caid);
244
245 /* If ID mismatch or other error then return */
246 if (i <= 0)
247 return i;
248
249 signer = sk_X509_value(chain, 0);
250 /* Check to see if OCSP responder CA matches request CA */
251 if (sk_X509_num(chain) > 1) {
252 sca = sk_X509_value(chain, 1);
253 i = ocsp_match_issuerid(sca, caid, sresp);
254 if (i < 0)
255 return i;
256 if (i) {
257 /* We have a match, if extensions OK then success */
258 if (ocsp_check_delegated(signer, flags))
259 return 1;
260 return 0;
261 }
262 }
263
264 /* Otherwise check if OCSP request signed directly by request CA */
265 return ocsp_match_issuerid(signer, caid, sresp);
266}
267
268/*
269 * Check the issuer certificate IDs for equality. If there is a mismatch with
270 * the same algorithm then there's no point trying to match any certificates
271 * against the issuer. If the issuer IDs all match then we just need to check
272 * equality against one of them.
e8af92fc 273 */
0f113f3e 274
e8af92fc 275static int ocsp_check_ids(STACK_OF(OCSP_SINGLERESP) *sresp, OCSP_CERTID **ret)
0f113f3e
MC
276{
277 OCSP_CERTID *tmpid, *cid;
278 int i, idcount;
279
280 idcount = sk_OCSP_SINGLERESP_num(sresp);
281 if (idcount <= 0) {
282 OCSPerr(OCSP_F_OCSP_CHECK_IDS,
283 OCSP_R_RESPONSE_CONTAINS_NO_REVOCATION_DATA);
284 return -1;
285 }
286
287 cid = sk_OCSP_SINGLERESP_value(sresp, 0)->certId;
288
289 *ret = NULL;
290
291 for (i = 1; i < idcount; i++) {
292 tmpid = sk_OCSP_SINGLERESP_value(sresp, i)->certId;
293 /* Check to see if IDs match */
294 if (OCSP_id_issuer_cmp(cid, tmpid)) {
295 /* If algoritm mismatch let caller deal with it */
296 if (OBJ_cmp(tmpid->hashAlgorithm->algorithm,
297 cid->hashAlgorithm->algorithm))
298 return 2;
299 /* Else mismatch */
300 return 0;
301 }
302 }
e8af92fc 303
0f113f3e
MC
304 /* All IDs match: only need to check one ID */
305 *ret = cid;
306 return 1;
307}
e8af92fc
DSH
308
309static int ocsp_match_issuerid(X509 *cert, OCSP_CERTID *cid,
0f113f3e
MC
310 STACK_OF(OCSP_SINGLERESP) *sresp)
311{
312 /* If only one ID to match then do it */
313 if (cid) {
314 const EVP_MD *dgst;
315 X509_NAME *iname;
316 int mdlen;
317 unsigned char md[EVP_MAX_MD_SIZE];
318 if (!(dgst = EVP_get_digestbyobj(cid->hashAlgorithm->algorithm))) {
319 OCSPerr(OCSP_F_OCSP_MATCH_ISSUERID,
320 OCSP_R_UNKNOWN_MESSAGE_DIGEST);
321 return -1;
322 }
323
324 mdlen = EVP_MD_size(dgst);
325 if (mdlen < 0)
326 return -1;
327 if ((cid->issuerNameHash->length != mdlen) ||
328 (cid->issuerKeyHash->length != mdlen))
329 return 0;
330 iname = X509_get_subject_name(cert);
331 if (!X509_NAME_digest(iname, dgst, md, NULL))
332 return -1;
333 if (memcmp(md, cid->issuerNameHash->data, mdlen))
334 return 0;
335 X509_pubkey_digest(cert, dgst, md, NULL);
336 if (memcmp(md, cid->issuerKeyHash->data, mdlen))
337 return 0;
338
339 return 1;
340
341 } else {
342 /* We have to match the whole lot */
343 int i, ret;
344 OCSP_CERTID *tmpid;
345 for (i = 0; i < sk_OCSP_SINGLERESP_num(sresp); i++) {
346 tmpid = sk_OCSP_SINGLERESP_value(sresp, i)->certId;
347 ret = ocsp_match_issuerid(cert, tmpid, NULL);
348 if (ret <= 0)
349 return ret;
350 }
351 return 1;
352 }
353
354}
e8af92fc
DSH
355
356static int ocsp_check_delegated(X509 *x, int flags)
0f113f3e
MC
357{
358 X509_check_purpose(x, -1, 0);
359 if ((x->ex_flags & EXFLAG_XKUSAGE) && (x->ex_xkusage & XKU_OCSP_SIGN))
360 return 1;
361 OCSPerr(OCSP_F_OCSP_CHECK_DELEGATED, OCSP_R_MISSING_OCSPSIGNING_USAGE);
362 return 0;
363}
364
365/*
366 * Verify an OCSP request. This is fortunately much easier than OCSP response
367 * verify. Just find the signers certificate and verify it against a given
368 * trust value.
fafc7f98
DSH
369 */
370
0f113f3e
MC
371int OCSP_request_verify(OCSP_REQUEST *req, STACK_OF(X509) *certs,
372 X509_STORE *store, unsigned long flags)
373{
374 X509 *signer;
375 X509_NAME *nm;
376 GENERAL_NAME *gen;
377 int ret;
378 X509_STORE_CTX ctx;
379 if (!req->optionalSignature) {
380 OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY, OCSP_R_REQUEST_NOT_SIGNED);
381 return 0;
382 }
383 gen = req->tbsRequest->requestorName;
384 if (!gen || gen->type != GEN_DIRNAME) {
385 OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY,
386 OCSP_R_UNSUPPORTED_REQUESTORNAME_TYPE);
387 return 0;
388 }
389 nm = gen->d.directoryName;
390 ret = ocsp_req_find_signer(&signer, req, nm, certs, store, flags);
391 if (ret <= 0) {
392 OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY,
393 OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND);
394 return 0;
395 }
396 if ((ret == 2) && (flags & OCSP_TRUSTOTHER))
397 flags |= OCSP_NOVERIFY;
398 if (!(flags & OCSP_NOSIGS)) {
399 EVP_PKEY *skey;
400 skey = X509_get_pubkey(signer);
401 ret = OCSP_REQUEST_verify(req, skey);
402 EVP_PKEY_free(skey);
403 if (ret <= 0) {
404 OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY, OCSP_R_SIGNATURE_FAILURE);
405 return 0;
406 }
407 }
408 if (!(flags & OCSP_NOVERIFY)) {
409 int init_res;
410 if (flags & OCSP_NOCHAIN)
411 init_res = X509_STORE_CTX_init(&ctx, store, signer, NULL);
412 else
413 init_res = X509_STORE_CTX_init(&ctx, store, signer,
414 req->optionalSignature->certs);
415 if (!init_res) {
416 OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY, ERR_R_X509_LIB);
417 return 0;
fafc7f98
DSH
418 }
419
0f113f3e
MC
420 X509_STORE_CTX_set_purpose(&ctx, X509_PURPOSE_OCSP_HELPER);
421 X509_STORE_CTX_set_trust(&ctx, X509_TRUST_OCSP_REQUEST);
422 ret = X509_verify_cert(&ctx);
423 X509_STORE_CTX_cleanup(&ctx);
424 if (ret <= 0) {
425 ret = X509_STORE_CTX_get_error(&ctx);
426 OCSPerr(OCSP_F_OCSP_REQUEST_VERIFY,
427 OCSP_R_CERTIFICATE_VERIFY_ERROR);
428 ERR_add_error_data(2, "Verify error:",
429 X509_verify_cert_error_string(ret));
430 return 0;
431 }
432 }
433 return 1;
434}
435
436static int ocsp_req_find_signer(X509 **psigner, OCSP_REQUEST *req,
437 X509_NAME *nm, STACK_OF(X509) *certs,
438 X509_STORE *st, unsigned long flags)
439{
440 X509 *signer;
441 if (!(flags & OCSP_NOINTERN)) {
442 signer = X509_find_by_subject(req->optionalSignature->certs, nm);
443 if (signer) {
444 *psigner = signer;
445 return 1;
446 }
447 }
448
449 signer = X509_find_by_subject(certs, nm);
450 if (signer) {
451 *psigner = signer;
452 return 2;
453 }
454 return 0;
455}