1 /* $OpenBSD: ocsp_cl.c,v 1.21 2022/01/07 09:45:52 tb Exp $ */
2 /* Written by Tom Titchener <Tom_Titchener@groove.net> for the OpenSSL
3  * project. */
4 
5 /* History:
6    This file was transfered to Richard Levitte from CertCo by Kathy
7    Weinhold in mid-spring 2000 to be included in OpenSSL or released
8    as a patch kit. */
9 
10 /* ====================================================================
11  * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  *
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  *
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in
22  *    the documentation and/or other materials provided with the
23  *    distribution.
24  *
25  * 3. All advertising materials mentioning features or use of this
26  *    software must display the following acknowledgment:
27  *    "This product includes software developed by the OpenSSL Project
28  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
29  *
30  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
31  *    endorse or promote products derived from this software without
32  *    prior written permission. For written permission, please contact
33  *    openssl-core@openssl.org.
34  *
35  * 5. Products derived from this software may not be called "OpenSSL"
36  *    nor may "OpenSSL" appear in their names without prior written
37  *    permission of the OpenSSL Project.
38  *
39  * 6. Redistributions of any form whatsoever must retain the following
40  *    acknowledgment:
41  *    "This product includes software developed by the OpenSSL Project
42  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
43  *
44  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
45  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
47  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
48  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
49  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
50  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
51  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
53  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
54  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
55  * OF THE POSSIBILITY OF SUCH DAMAGE.
56  * ====================================================================
57  *
58  * This product includes cryptographic software written by Eric Young
59  * (eay@cryptsoft.com).  This product includes software written by Tim
60  * Hudson (tjh@cryptsoft.com).
61  *
62  */
63 
64 #include <stdio.h>
65 #include <time.h>
66 
67 #include <openssl/err.h>
68 #include <openssl/ocsp.h>
69 #include <openssl/objects.h>
70 #include <openssl/pem.h>
71 #include <openssl/x509.h>
72 #include <openssl/x509v3.h>
73 
74 #include "ocsp_local.h"
75 
76 /* Utility functions related to sending OCSP requests and extracting
77  * relevant information from the response.
78  */
79 
80 /* Add an OCSP_CERTID to an OCSP request. Return new OCSP_ONEREQ
81  * pointer: useful if we want to add extensions.
82  */
83 OCSP_ONEREQ *
84 OCSP_request_add0_id(OCSP_REQUEST *req, OCSP_CERTID *cid)
85 {
86 	OCSP_ONEREQ *one;
87 
88 	if ((one = OCSP_ONEREQ_new()) == NULL)
89 		goto err;
90 	if (req != NULL) {
91 		if (!sk_OCSP_ONEREQ_push(req->tbsRequest->requestList, one))
92 			goto err;
93 	}
94 	OCSP_CERTID_free(one->reqCert);
95 	one->reqCert = cid;
96 	return one;
97 
98  err:
99 	OCSP_ONEREQ_free(one);
100 	return NULL;
101 }
102 
103 /* Set requestorName from an X509_NAME structure */
104 int
105 OCSP_request_set1_name(OCSP_REQUEST *req, X509_NAME *nm)
106 {
107 	GENERAL_NAME *gen;
108 
109 	gen = GENERAL_NAME_new();
110 	if (gen == NULL)
111 		return 0;
112 	if (!X509_NAME_set(&gen->d.directoryName, nm)) {
113 		GENERAL_NAME_free(gen);
114 		return 0;
115 	}
116 	gen->type = GEN_DIRNAME;
117 	if (req->tbsRequest->requestorName)
118 		GENERAL_NAME_free(req->tbsRequest->requestorName);
119 	req->tbsRequest->requestorName = gen;
120 	return 1;
121 }
122 
123 /* Add a certificate to an OCSP request */
124 int
125 OCSP_request_add1_cert(OCSP_REQUEST *req, X509 *cert)
126 {
127 	OCSP_SIGNATURE *sig;
128 
129 	if (!req->optionalSignature)
130 		req->optionalSignature = OCSP_SIGNATURE_new();
131 	sig = req->optionalSignature;
132 	if (!sig)
133 		return 0;
134 	if (!cert)
135 		return 1;
136 	if (!sig->certs && !(sig->certs = sk_X509_new_null()))
137 		return 0;
138 
139 	if (!sk_X509_push(sig->certs, cert))
140 		return 0;
141 	X509_up_ref(cert);
142 	return 1;
143 }
144 
145 /* Sign an OCSP request set the requestorName to the subject
146  * name of an optional signers certificate and include one
147  * or more optional certificates in the request. Behaves
148  * like PKCS7_sign().
149  */
150 int
151 OCSP_request_sign(OCSP_REQUEST *req, X509 *signer, EVP_PKEY *key,
152     const EVP_MD *dgst, STACK_OF(X509) *certs, unsigned long flags)
153 {
154 	int i;
155 	OCSP_SIGNATURE *sig;
156 	X509 *x;
157 
158 	if (!OCSP_request_set1_name(req, X509_get_subject_name(signer)))
159 		goto err;
160 
161 	if (!(req->optionalSignature = sig = OCSP_SIGNATURE_new()))
162 		goto err;
163 	if (key) {
164 		if (!X509_check_private_key(signer, key)) {
165 			OCSPerror(OCSP_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
166 			goto err;
167 		}
168 		if (!OCSP_REQUEST_sign(req, key, dgst))
169 			goto err;
170 	}
171 
172 	if (!(flags & OCSP_NOCERTS)) {
173 		if (!OCSP_request_add1_cert(req, signer))
174 			goto err;
175 		for (i = 0; i < sk_X509_num(certs); i++) {
176 			x = sk_X509_value(certs, i);
177 			if (!OCSP_request_add1_cert(req, x))
178 				goto err;
179 		}
180 	}
181 
182 	return 1;
183 
184 err:
185 	OCSP_SIGNATURE_free(req->optionalSignature);
186 	req->optionalSignature = NULL;
187 	return 0;
188 }
189 
190 /* Get response status */
191 int
192 OCSP_response_status(OCSP_RESPONSE *resp)
193 {
194 	return ASN1_ENUMERATED_get(resp->responseStatus);
195 }
196 
197 /* Extract basic response from OCSP_RESPONSE or NULL if
198  * no basic response present.
199  */
200 OCSP_BASICRESP *
201 OCSP_response_get1_basic(OCSP_RESPONSE *resp)
202 {
203 	OCSP_RESPBYTES *rb;
204 
205 	rb = resp->responseBytes;
206 	if (!rb) {
207 		OCSPerror(OCSP_R_NO_RESPONSE_DATA);
208 		return NULL;
209 	}
210 	if (OBJ_obj2nid(rb->responseType) != NID_id_pkix_OCSP_basic) {
211 		OCSPerror(OCSP_R_NOT_BASIC_RESPONSE);
212 		return NULL;
213 	}
214 
215 	return ASN1_item_unpack(rb->response, &OCSP_BASICRESP_it);
216 }
217 
218 /* Return number of OCSP_SINGLERESP reponses present in
219  * a basic response.
220  */
221 int
222 OCSP_resp_count(OCSP_BASICRESP *bs)
223 {
224 	if (!bs)
225 		return -1;
226 	return sk_OCSP_SINGLERESP_num(bs->tbsResponseData->responses);
227 }
228 
229 /* Extract an OCSP_SINGLERESP response with a given index */
230 OCSP_SINGLERESP *
231 OCSP_resp_get0(OCSP_BASICRESP *bs, int idx)
232 {
233 	if (!bs)
234 		return NULL;
235 	return sk_OCSP_SINGLERESP_value(bs->tbsResponseData->responses, idx);
236 }
237 
238 const ASN1_GENERALIZEDTIME *
239 OCSP_resp_get0_produced_at(const OCSP_BASICRESP *bs)
240 {
241 	return bs->tbsResponseData->producedAt;
242 }
243 
244 const STACK_OF(X509) *
245 OCSP_resp_get0_certs(const OCSP_BASICRESP *bs)
246 {
247 	return bs->certs;
248 }
249 
250 int
251 OCSP_resp_get0_id(const OCSP_BASICRESP *bs, const ASN1_OCTET_STRING **pid,
252     const X509_NAME **pname)
253 {
254 	const OCSP_RESPID *rid = bs->tbsResponseData->responderId;
255 
256 	if (rid->type == V_OCSP_RESPID_NAME) {
257 		*pname = rid->value.byName;
258 		*pid = NULL;
259 	} else if (rid->type == V_OCSP_RESPID_KEY) {
260 		*pid = rid->value.byKey;
261 		*pname = NULL;
262 	} else {
263 		return 0;
264 	}
265 
266 	return 1;
267 }
268 
269 const ASN1_OCTET_STRING *
270 OCSP_resp_get0_signature(const OCSP_BASICRESP *bs)
271 {
272 	return bs->signature;
273 }
274 
275 const X509_ALGOR *
276 OCSP_resp_get0_tbs_sigalg(const OCSP_BASICRESP *bs)
277 {
278 	return bs->signatureAlgorithm;
279 }
280 
281 const OCSP_RESPDATA *
282 OCSP_resp_get0_respdata(const OCSP_BASICRESP *bs)
283 {
284 	return bs->tbsResponseData;
285 }
286 
287 /* Look single response matching a given certificate ID */
288 int
289 OCSP_resp_find(OCSP_BASICRESP *bs, OCSP_CERTID *id, int last)
290 {
291 	int i;
292 	STACK_OF(OCSP_SINGLERESP) *sresp;
293 	OCSP_SINGLERESP *single;
294 
295 	if (!bs)
296 		return -1;
297 	if (last < 0)
298 		last = 0;
299 	else
300 		last++;
301 	sresp = bs->tbsResponseData->responses;
302 	for (i = last; i < sk_OCSP_SINGLERESP_num(sresp); i++) {
303 		single = sk_OCSP_SINGLERESP_value(sresp, i);
304 		if (!OCSP_id_cmp(id, single->certId))
305 			return i;
306 	}
307 	return -1;
308 }
309 
310 /* Extract status information from an OCSP_SINGLERESP structure.
311  * Note: the revtime and reason values are only set if the
312  * certificate status is revoked. Returns numerical value of
313  * status.
314  */
315 int
316 OCSP_single_get0_status(OCSP_SINGLERESP *single, int *reason,
317     ASN1_GENERALIZEDTIME **revtime, ASN1_GENERALIZEDTIME **thisupd,
318     ASN1_GENERALIZEDTIME **nextupd)
319 {
320 	int ret;
321 	OCSP_CERTSTATUS *cst;
322 
323 	if (!single)
324 		return -1;
325 	cst = single->certStatus;
326 	ret = cst->type;
327 	if (ret == V_OCSP_CERTSTATUS_REVOKED) {
328 		OCSP_REVOKEDINFO *rev = cst->value.revoked;
329 
330 		if (revtime)
331 			*revtime = rev->revocationTime;
332 		if (reason) {
333 			if (rev->revocationReason)
334 				*reason = ASN1_ENUMERATED_get(
335 				    rev->revocationReason);
336 			else
337 				*reason = -1;
338 		}
339 	}
340 	if (thisupd)
341 		*thisupd = single->thisUpdate;
342 	if (nextupd)
343 		*nextupd = single->nextUpdate;
344 	return ret;
345 }
346 
347 /* This function combines the previous ones: look up a certificate ID and
348  * if found extract status information. Return 0 is successful.
349  */
350 int
351 OCSP_resp_find_status(OCSP_BASICRESP *bs, OCSP_CERTID *id, int *status,
352     int *reason, ASN1_GENERALIZEDTIME **revtime, ASN1_GENERALIZEDTIME **thisupd,
353     ASN1_GENERALIZEDTIME **nextupd)
354 {
355 	int i;
356 	OCSP_SINGLERESP *single;
357 
358 	i = OCSP_resp_find(bs, id, -1);
359 	/* Maybe check for multiple responses and give an error? */
360 	if (i < 0)
361 		return 0;
362 	single = OCSP_resp_get0(bs, i);
363 	i = OCSP_single_get0_status(single, reason, revtime, thisupd, nextupd);
364 	if (status)
365 		*status = i;
366 	return 1;
367 }
368 
369 /* Check validity of thisUpdate and nextUpdate fields. It is possible that the request will
370  * take a few seconds to process and/or the time wont be totally accurate. Therefore to avoid
371  * rejecting otherwise valid time we allow the times to be within 'nsec' of the current time.
372  * Also to avoid accepting very old responses without a nextUpdate field an optional maxage
373  * parameter specifies the maximum age the thisUpdate field can be.
374  */
375 int
376 OCSP_check_validity(ASN1_GENERALIZEDTIME *thisupd,
377     ASN1_GENERALIZEDTIME *nextupd, long nsec, long maxsec)
378 {
379 	time_t t_now, t_tmp;
380 	struct tm tm_this, tm_next, tm_tmp;
381 
382 	time(&t_now);
383 
384 	/*
385 	 * Times must explicitly be a GENERALIZEDTIME as per section
386 	 * 4.2.2.1 of RFC 6960 - It is invalid to accept other times
387 	 * (such as UTCTIME permitted/required by RFC 5280 for certificates)
388 	 */
389 
390 	/* Check thisUpdate is valid and not more than nsec in the future */
391 	if (ASN1_time_parse(thisupd->data, thisupd->length, &tm_this,
392 	    V_ASN1_GENERALIZEDTIME) != V_ASN1_GENERALIZEDTIME) {
393 		OCSPerror(OCSP_R_ERROR_IN_THISUPDATE_FIELD);
394 		return 0;
395 	} else {
396 		t_tmp = t_now + nsec;
397 		if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
398 			return 0;
399 		if (ASN1_time_tm_cmp(&tm_this, &tm_tmp) > 0) {
400 			OCSPerror(OCSP_R_STATUS_NOT_YET_VALID);
401 			return 0;
402 		}
403 
404 		/*
405 		 * If maxsec specified check thisUpdate is not more than maxsec
406 		 * in the past
407 		 */
408 		if (maxsec >= 0) {
409 			t_tmp = t_now - maxsec;
410 			if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
411 				return 0;
412 			if (ASN1_time_tm_cmp(&tm_this, &tm_tmp) < 0) {
413 				OCSPerror(OCSP_R_STATUS_TOO_OLD);
414 				return 0;
415 			}
416 		}
417 	}
418 
419 	if (!nextupd)
420 		return 1;
421 
422 	/* Check nextUpdate is valid and not more than nsec in the past */
423 	if (ASN1_time_parse(nextupd->data, nextupd->length, &tm_next,
424 	    V_ASN1_GENERALIZEDTIME) != V_ASN1_GENERALIZEDTIME) {
425 		OCSPerror(OCSP_R_ERROR_IN_NEXTUPDATE_FIELD);
426 		return 0;
427 	} else {
428 		t_tmp = t_now - nsec;
429 		if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
430 			return 0;
431 		if (ASN1_time_tm_cmp(&tm_next, &tm_tmp) < 0) {
432 			OCSPerror(OCSP_R_STATUS_EXPIRED);
433 			return 0;
434 		}
435 	}
436 
437 	/* Also don't allow nextUpdate to precede thisUpdate */
438 	if (ASN1_time_tm_cmp(&tm_next, &tm_this) < 0) {
439 		OCSPerror(OCSP_R_NEXTUPDATE_BEFORE_THISUPDATE);
440 		return 0;
441 	}
442 
443 	return 1;
444 }
445 
446 const OCSP_CERTID *
447 OCSP_SINGLERESP_get0_id(const OCSP_SINGLERESP *single)
448 {
449 	return single->certId;
450 }
451