1 /* $OpenBSD: ocsp_cl.c,v 1.16 2018/11/25 19:48:43 jmc 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 /* Utility functions related to sending OCSP requests and extracting
75  * relevant information from the response.
76  */
77 
78 /* Add an OCSP_CERTID to an OCSP request. Return new OCSP_ONEREQ
79  * pointer: useful if we want to add extensions.
80  */
81 OCSP_ONEREQ *
82 OCSP_request_add0_id(OCSP_REQUEST *req, OCSP_CERTID *cid)
83 {
84 	OCSP_ONEREQ *one = NULL;
85 
86 	if (!(one = OCSP_ONEREQ_new()))
87 		goto err;
88 	if (one->reqCert)
89 		OCSP_CERTID_free(one->reqCert);
90 	one->reqCert = cid;
91 	if (req && !sk_OCSP_ONEREQ_push(req->tbsRequest->requestList, one))
92 		goto err;
93 	return one;
94 
95 err:
96 	OCSP_ONEREQ_free(one);
97 	return NULL;
98 }
99 
100 /* Set requestorName from an X509_NAME structure */
101 int
102 OCSP_request_set1_name(OCSP_REQUEST *req, X509_NAME *nm)
103 {
104 	GENERAL_NAME *gen;
105 
106 	gen = GENERAL_NAME_new();
107 	if (gen == NULL)
108 		return 0;
109 	if (!X509_NAME_set(&gen->d.directoryName, nm)) {
110 		GENERAL_NAME_free(gen);
111 		return 0;
112 	}
113 	gen->type = GEN_DIRNAME;
114 	if (req->tbsRequest->requestorName)
115 		GENERAL_NAME_free(req->tbsRequest->requestorName);
116 	req->tbsRequest->requestorName = gen;
117 	return 1;
118 }
119 
120 /* Add a certificate to an OCSP request */
121 int
122 OCSP_request_add1_cert(OCSP_REQUEST *req, X509 *cert)
123 {
124 	OCSP_SIGNATURE *sig;
125 
126 	if (!req->optionalSignature)
127 		req->optionalSignature = OCSP_SIGNATURE_new();
128 	sig = req->optionalSignature;
129 	if (!sig)
130 		return 0;
131 	if (!cert)
132 		return 1;
133 	if (!sig->certs && !(sig->certs = sk_X509_new_null()))
134 		return 0;
135 
136 	if (!sk_X509_push(sig->certs, cert))
137 		return 0;
138 	CRYPTO_add(&cert->references, 1, CRYPTO_LOCK_X509);
139 	return 1;
140 }
141 
142 /* Sign an OCSP request set the requestorName to the subject
143  * name of an optional signers certificate and include one
144  * or more optional certificates in the request. Behaves
145  * like PKCS7_sign().
146  */
147 int
148 OCSP_request_sign(OCSP_REQUEST *req, X509 *signer, EVP_PKEY *key,
149     const EVP_MD *dgst, STACK_OF(X509) *certs, unsigned long flags)
150 {
151 	int i;
152 	OCSP_SIGNATURE *sig;
153 	X509 *x;
154 
155 	if (!OCSP_request_set1_name(req, X509_get_subject_name(signer)))
156 		goto err;
157 
158 	if (!(req->optionalSignature = sig = OCSP_SIGNATURE_new()))
159 		goto err;
160 	if (key) {
161 		if (!X509_check_private_key(signer, key)) {
162 			OCSPerror(OCSP_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
163 			goto err;
164 		}
165 		if (!OCSP_REQUEST_sign(req, key, dgst))
166 			goto err;
167 	}
168 
169 	if (!(flags & OCSP_NOCERTS)) {
170 		if (!OCSP_request_add1_cert(req, signer))
171 			goto err;
172 		for (i = 0; i < sk_X509_num(certs); i++) {
173 			x = sk_X509_value(certs, i);
174 			if (!OCSP_request_add1_cert(req, x))
175 				goto err;
176 		}
177 	}
178 
179 	return 1;
180 
181 err:
182 	OCSP_SIGNATURE_free(req->optionalSignature);
183 	req->optionalSignature = NULL;
184 	return 0;
185 }
186 
187 /* Get response status */
188 int
189 OCSP_response_status(OCSP_RESPONSE *resp)
190 {
191 	return ASN1_ENUMERATED_get(resp->responseStatus);
192 }
193 
194 /* Extract basic response from OCSP_RESPONSE or NULL if
195  * no basic response present.
196  */
197 OCSP_BASICRESP *
198 OCSP_response_get1_basic(OCSP_RESPONSE *resp)
199 {
200 	OCSP_RESPBYTES *rb;
201 
202 	rb = resp->responseBytes;
203 	if (!rb) {
204 		OCSPerror(OCSP_R_NO_RESPONSE_DATA);
205 		return NULL;
206 	}
207 	if (OBJ_obj2nid(rb->responseType) != NID_id_pkix_OCSP_basic) {
208 		OCSPerror(OCSP_R_NOT_BASIC_RESPONSE);
209 		return NULL;
210 	}
211 
212 	return ASN1_item_unpack(rb->response, &OCSP_BASICRESP_it);
213 }
214 
215 /* Return number of OCSP_SINGLERESP reponses present in
216  * a basic response.
217  */
218 int
219 OCSP_resp_count(OCSP_BASICRESP *bs)
220 {
221 	if (!bs)
222 		return -1;
223 	return sk_OCSP_SINGLERESP_num(bs->tbsResponseData->responses);
224 }
225 
226 /* Extract an OCSP_SINGLERESP response with a given index */
227 OCSP_SINGLERESP *
228 OCSP_resp_get0(OCSP_BASICRESP *bs, int idx)
229 {
230 	if (!bs)
231 		return NULL;
232 	return sk_OCSP_SINGLERESP_value(bs->tbsResponseData->responses, idx);
233 }
234 
235 /* Look single response matching a given certificate ID */
236 int
237 OCSP_resp_find(OCSP_BASICRESP *bs, OCSP_CERTID *id, int last)
238 {
239 	int i;
240 	STACK_OF(OCSP_SINGLERESP) *sresp;
241 	OCSP_SINGLERESP *single;
242 
243 	if (!bs)
244 		return -1;
245 	if (last < 0)
246 		last = 0;
247 	else
248 		last++;
249 	sresp = bs->tbsResponseData->responses;
250 	for (i = last; i < sk_OCSP_SINGLERESP_num(sresp); i++) {
251 		single = sk_OCSP_SINGLERESP_value(sresp, i);
252 		if (!OCSP_id_cmp(id, single->certId))
253 			return i;
254 	}
255 	return -1;
256 }
257 
258 /* Extract status information from an OCSP_SINGLERESP structure.
259  * Note: the revtime and reason values are only set if the
260  * certificate status is revoked. Returns numerical value of
261  * status.
262  */
263 int
264 OCSP_single_get0_status(OCSP_SINGLERESP *single, int *reason,
265     ASN1_GENERALIZEDTIME **revtime, ASN1_GENERALIZEDTIME **thisupd,
266     ASN1_GENERALIZEDTIME **nextupd)
267 {
268 	int ret;
269 	OCSP_CERTSTATUS *cst;
270 
271 	if (!single)
272 		return -1;
273 	cst = single->certStatus;
274 	ret = cst->type;
275 	if (ret == V_OCSP_CERTSTATUS_REVOKED) {
276 		OCSP_REVOKEDINFO *rev = cst->value.revoked;
277 
278 		if (revtime)
279 			*revtime = rev->revocationTime;
280 		if (reason) {
281 			if (rev->revocationReason)
282 				*reason = ASN1_ENUMERATED_get(
283 				    rev->revocationReason);
284 			else
285 				*reason = -1;
286 		}
287 	}
288 	if (thisupd)
289 		*thisupd = single->thisUpdate;
290 	if (nextupd)
291 		*nextupd = single->nextUpdate;
292 	return ret;
293 }
294 
295 /* This function combines the previous ones: look up a certificate ID and
296  * if found extract status information. Return 0 is successful.
297  */
298 int
299 OCSP_resp_find_status(OCSP_BASICRESP *bs, OCSP_CERTID *id, int *status,
300     int *reason, ASN1_GENERALIZEDTIME **revtime, ASN1_GENERALIZEDTIME **thisupd,
301     ASN1_GENERALIZEDTIME **nextupd)
302 {
303 	int i;
304 	OCSP_SINGLERESP *single;
305 
306 	i = OCSP_resp_find(bs, id, -1);
307 	/* Maybe check for multiple responses and give an error? */
308 	if (i < 0)
309 		return 0;
310 	single = OCSP_resp_get0(bs, i);
311 	i = OCSP_single_get0_status(single, reason, revtime, thisupd, nextupd);
312 	if (status)
313 		*status = i;
314 	return 1;
315 }
316 
317 /* Check validity of thisUpdate and nextUpdate fields. It is possible that the request will
318  * take a few seconds to process and/or the time wont be totally accurate. Therefore to avoid
319  * rejecting otherwise valid time we allow the times to be within 'nsec' of the current time.
320  * Also to avoid accepting very old responses without a nextUpdate field an optional maxage
321  * parameter specifies the maximum age the thisUpdate field can be.
322  */
323 int
324 OCSP_check_validity(ASN1_GENERALIZEDTIME *thisupd,
325     ASN1_GENERALIZEDTIME *nextupd, long nsec, long maxsec)
326 {
327 	time_t t_now, t_tmp;
328 	struct tm tm_this, tm_next, tm_tmp;
329 
330 	time(&t_now);
331 
332 	/*
333 	 * Times must explicitly be a GENERALIZEDTIME as per section
334 	 * 4.2.2.1 of RFC 6960 - It is invalid to accept other times
335 	 * (such as UTCTIME permitted/required by RFC 5280 for certificates)
336 	 */
337 
338 	/* Check thisUpdate is valid and not more than nsec in the future */
339 	if (ASN1_time_parse(thisupd->data, thisupd->length, &tm_this,
340 	    V_ASN1_GENERALIZEDTIME) != V_ASN1_GENERALIZEDTIME) {
341 		OCSPerror(OCSP_R_ERROR_IN_THISUPDATE_FIELD);
342 		return 0;
343 	} else {
344 		t_tmp = t_now + nsec;
345 		if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
346 			return 0;
347 		if (ASN1_time_tm_cmp(&tm_this, &tm_tmp) > 0) {
348 			OCSPerror(OCSP_R_STATUS_NOT_YET_VALID);
349 			return 0;
350 		}
351 
352 		/*
353 		 * If maxsec specified check thisUpdate is not more than maxsec
354 		 * in the past
355 		 */
356 		if (maxsec >= 0) {
357 			t_tmp = t_now - maxsec;
358 			if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
359 				return 0;
360 			if (ASN1_time_tm_cmp(&tm_this, &tm_tmp) < 0) {
361 				OCSPerror(OCSP_R_STATUS_TOO_OLD);
362 				return 0;
363 			}
364 		}
365 	}
366 
367 	if (!nextupd)
368 		return 1;
369 
370 	/* Check nextUpdate is valid and not more than nsec in the past */
371 	if (ASN1_time_parse(nextupd->data, nextupd->length, &tm_next,
372 	    V_ASN1_GENERALIZEDTIME) != V_ASN1_GENERALIZEDTIME) {
373 		OCSPerror(OCSP_R_ERROR_IN_NEXTUPDATE_FIELD);
374 		return 0;
375 	} else {
376 		t_tmp = t_now - nsec;
377 		if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
378 			return 0;
379 		if (ASN1_time_tm_cmp(&tm_next, &tm_tmp) < 0) {
380 			OCSPerror(OCSP_R_STATUS_EXPIRED);
381 			return 0;
382 		}
383 	}
384 
385 	/* Also don't allow nextUpdate to precede thisUpdate */
386 	if (ASN1_time_tm_cmp(&tm_next, &tm_this) < 0) {
387 		OCSPerror(OCSP_R_NEXTUPDATE_BEFORE_THISUPDATE);
388 		return 0;
389 	}
390 
391 	return 1;
392 }
393 
394 const OCSP_CERTID *
395 OCSP_SINGLERESP_get0_id(const OCSP_SINGLERESP *single)
396 {
397 	return single->certId;
398 }
399