1 /* $OpenBSD: ocsp_cl.c,v 1.17 2020/10/09 17:19:35 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 /* 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 *
OCSP_request_add0_id(OCSP_REQUEST * req,OCSP_CERTID * cid)82 OCSP_request_add0_id(OCSP_REQUEST *req, OCSP_CERTID *cid)
83 {
84 	OCSP_ONEREQ *one;
85 
86 	if ((one = OCSP_ONEREQ_new()) == NULL)
87 		goto err;
88 	if (req != NULL) {
89 	       	if (!sk_OCSP_ONEREQ_push(req->tbsRequest->requestList, one))
90 			goto err;
91 	}
92 	OCSP_CERTID_free(one->reqCert);
93 	one->reqCert = cid;
94 	return one;
95 
96  err:
97 	OCSP_ONEREQ_free(one);
98 	return NULL;
99 }
100 
101 /* Set requestorName from an X509_NAME structure */
102 int
OCSP_request_set1_name(OCSP_REQUEST * req,X509_NAME * nm)103 OCSP_request_set1_name(OCSP_REQUEST *req, X509_NAME *nm)
104 {
105 	GENERAL_NAME *gen;
106 
107 	gen = GENERAL_NAME_new();
108 	if (gen == NULL)
109 		return 0;
110 	if (!X509_NAME_set(&gen->d.directoryName, nm)) {
111 		GENERAL_NAME_free(gen);
112 		return 0;
113 	}
114 	gen->type = GEN_DIRNAME;
115 	if (req->tbsRequest->requestorName)
116 		GENERAL_NAME_free(req->tbsRequest->requestorName);
117 	req->tbsRequest->requestorName = gen;
118 	return 1;
119 }
120 
121 /* Add a certificate to an OCSP request */
122 int
OCSP_request_add1_cert(OCSP_REQUEST * req,X509 * cert)123 OCSP_request_add1_cert(OCSP_REQUEST *req, X509 *cert)
124 {
125 	OCSP_SIGNATURE *sig;
126 
127 	if (!req->optionalSignature)
128 		req->optionalSignature = OCSP_SIGNATURE_new();
129 	sig = req->optionalSignature;
130 	if (!sig)
131 		return 0;
132 	if (!cert)
133 		return 1;
134 	if (!sig->certs && !(sig->certs = sk_X509_new_null()))
135 		return 0;
136 
137 	if (!sk_X509_push(sig->certs, cert))
138 		return 0;
139 	CRYPTO_add(&cert->references, 1, CRYPTO_LOCK_X509);
140 	return 1;
141 }
142 
143 /* Sign an OCSP request set the requestorName to the subject
144  * name of an optional signers certificate and include one
145  * or more optional certificates in the request. Behaves
146  * like PKCS7_sign().
147  */
148 int
OCSP_request_sign(OCSP_REQUEST * req,X509 * signer,EVP_PKEY * key,const EVP_MD * dgst,STACK_OF (X509)* certs,unsigned long flags)149 OCSP_request_sign(OCSP_REQUEST *req, X509 *signer, EVP_PKEY *key,
150     const EVP_MD *dgst, STACK_OF(X509) *certs, unsigned long flags)
151 {
152 	int i;
153 	OCSP_SIGNATURE *sig;
154 	X509 *x;
155 
156 	if (!OCSP_request_set1_name(req, X509_get_subject_name(signer)))
157 		goto err;
158 
159 	if (!(req->optionalSignature = sig = OCSP_SIGNATURE_new()))
160 		goto err;
161 	if (key) {
162 		if (!X509_check_private_key(signer, key)) {
163 			OCSPerror(OCSP_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
164 			goto err;
165 		}
166 		if (!OCSP_REQUEST_sign(req, key, dgst))
167 			goto err;
168 	}
169 
170 	if (!(flags & OCSP_NOCERTS)) {
171 		if (!OCSP_request_add1_cert(req, signer))
172 			goto err;
173 		for (i = 0; i < sk_X509_num(certs); i++) {
174 			x = sk_X509_value(certs, i);
175 			if (!OCSP_request_add1_cert(req, x))
176 				goto err;
177 		}
178 	}
179 
180 	return 1;
181 
182 err:
183 	OCSP_SIGNATURE_free(req->optionalSignature);
184 	req->optionalSignature = NULL;
185 	return 0;
186 }
187 
188 /* Get response status */
189 int
OCSP_response_status(OCSP_RESPONSE * resp)190 OCSP_response_status(OCSP_RESPONSE *resp)
191 {
192 	return ASN1_ENUMERATED_get(resp->responseStatus);
193 }
194 
195 /* Extract basic response from OCSP_RESPONSE or NULL if
196  * no basic response present.
197  */
198 OCSP_BASICRESP *
OCSP_response_get1_basic(OCSP_RESPONSE * resp)199 OCSP_response_get1_basic(OCSP_RESPONSE *resp)
200 {
201 	OCSP_RESPBYTES *rb;
202 
203 	rb = resp->responseBytes;
204 	if (!rb) {
205 		OCSPerror(OCSP_R_NO_RESPONSE_DATA);
206 		return NULL;
207 	}
208 	if (OBJ_obj2nid(rb->responseType) != NID_id_pkix_OCSP_basic) {
209 		OCSPerror(OCSP_R_NOT_BASIC_RESPONSE);
210 		return NULL;
211 	}
212 
213 	return ASN1_item_unpack(rb->response, &OCSP_BASICRESP_it);
214 }
215 
216 /* Return number of OCSP_SINGLERESP reponses present in
217  * a basic response.
218  */
219 int
OCSP_resp_count(OCSP_BASICRESP * bs)220 OCSP_resp_count(OCSP_BASICRESP *bs)
221 {
222 	if (!bs)
223 		return -1;
224 	return sk_OCSP_SINGLERESP_num(bs->tbsResponseData->responses);
225 }
226 
227 /* Extract an OCSP_SINGLERESP response with a given index */
228 OCSP_SINGLERESP *
OCSP_resp_get0(OCSP_BASICRESP * bs,int idx)229 OCSP_resp_get0(OCSP_BASICRESP *bs, int idx)
230 {
231 	if (!bs)
232 		return NULL;
233 	return sk_OCSP_SINGLERESP_value(bs->tbsResponseData->responses, idx);
234 }
235 
236 /* Look single response matching a given certificate ID */
237 int
OCSP_resp_find(OCSP_BASICRESP * bs,OCSP_CERTID * id,int last)238 OCSP_resp_find(OCSP_BASICRESP *bs, OCSP_CERTID *id, int last)
239 {
240 	int i;
241 	STACK_OF(OCSP_SINGLERESP) *sresp;
242 	OCSP_SINGLERESP *single;
243 
244 	if (!bs)
245 		return -1;
246 	if (last < 0)
247 		last = 0;
248 	else
249 		last++;
250 	sresp = bs->tbsResponseData->responses;
251 	for (i = last; i < sk_OCSP_SINGLERESP_num(sresp); i++) {
252 		single = sk_OCSP_SINGLERESP_value(sresp, i);
253 		if (!OCSP_id_cmp(id, single->certId))
254 			return i;
255 	}
256 	return -1;
257 }
258 
259 /* Extract status information from an OCSP_SINGLERESP structure.
260  * Note: the revtime and reason values are only set if the
261  * certificate status is revoked. Returns numerical value of
262  * status.
263  */
264 int
OCSP_single_get0_status(OCSP_SINGLERESP * single,int * reason,ASN1_GENERALIZEDTIME ** revtime,ASN1_GENERALIZEDTIME ** thisupd,ASN1_GENERALIZEDTIME ** nextupd)265 OCSP_single_get0_status(OCSP_SINGLERESP *single, int *reason,
266     ASN1_GENERALIZEDTIME **revtime, ASN1_GENERALIZEDTIME **thisupd,
267     ASN1_GENERALIZEDTIME **nextupd)
268 {
269 	int ret;
270 	OCSP_CERTSTATUS *cst;
271 
272 	if (!single)
273 		return -1;
274 	cst = single->certStatus;
275 	ret = cst->type;
276 	if (ret == V_OCSP_CERTSTATUS_REVOKED) {
277 		OCSP_REVOKEDINFO *rev = cst->value.revoked;
278 
279 		if (revtime)
280 			*revtime = rev->revocationTime;
281 		if (reason) {
282 			if (rev->revocationReason)
283 				*reason = ASN1_ENUMERATED_get(
284 				    rev->revocationReason);
285 			else
286 				*reason = -1;
287 		}
288 	}
289 	if (thisupd)
290 		*thisupd = single->thisUpdate;
291 	if (nextupd)
292 		*nextupd = single->nextUpdate;
293 	return ret;
294 }
295 
296 /* This function combines the previous ones: look up a certificate ID and
297  * if found extract status information. Return 0 is successful.
298  */
299 int
OCSP_resp_find_status(OCSP_BASICRESP * bs,OCSP_CERTID * id,int * status,int * reason,ASN1_GENERALIZEDTIME ** revtime,ASN1_GENERALIZEDTIME ** thisupd,ASN1_GENERALIZEDTIME ** nextupd)300 OCSP_resp_find_status(OCSP_BASICRESP *bs, OCSP_CERTID *id, int *status,
301     int *reason, ASN1_GENERALIZEDTIME **revtime, ASN1_GENERALIZEDTIME **thisupd,
302     ASN1_GENERALIZEDTIME **nextupd)
303 {
304 	int i;
305 	OCSP_SINGLERESP *single;
306 
307 	i = OCSP_resp_find(bs, id, -1);
308 	/* Maybe check for multiple responses and give an error? */
309 	if (i < 0)
310 		return 0;
311 	single = OCSP_resp_get0(bs, i);
312 	i = OCSP_single_get0_status(single, reason, revtime, thisupd, nextupd);
313 	if (status)
314 		*status = i;
315 	return 1;
316 }
317 
318 /* Check validity of thisUpdate and nextUpdate fields. It is possible that the request will
319  * take a few seconds to process and/or the time wont be totally accurate. Therefore to avoid
320  * rejecting otherwise valid time we allow the times to be within 'nsec' of the current time.
321  * Also to avoid accepting very old responses without a nextUpdate field an optional maxage
322  * parameter specifies the maximum age the thisUpdate field can be.
323  */
324 int
OCSP_check_validity(ASN1_GENERALIZEDTIME * thisupd,ASN1_GENERALIZEDTIME * nextupd,long nsec,long maxsec)325 OCSP_check_validity(ASN1_GENERALIZEDTIME *thisupd,
326     ASN1_GENERALIZEDTIME *nextupd, long nsec, long maxsec)
327 {
328 	time_t t_now, t_tmp;
329 	struct tm tm_this, tm_next, tm_tmp;
330 
331 	time(&t_now);
332 
333 	/*
334 	 * Times must explicitly be a GENERALIZEDTIME as per section
335 	 * 4.2.2.1 of RFC 6960 - It is invalid to accept other times
336 	 * (such as UTCTIME permitted/required by RFC 5280 for certificates)
337 	 */
338 
339 	/* Check thisUpdate is valid and not more than nsec in the future */
340 	if (ASN1_time_parse(thisupd->data, thisupd->length, &tm_this,
341 	    V_ASN1_GENERALIZEDTIME) != V_ASN1_GENERALIZEDTIME) {
342 		OCSPerror(OCSP_R_ERROR_IN_THISUPDATE_FIELD);
343 		return 0;
344 	} else {
345 		t_tmp = t_now + nsec;
346 		if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
347 			return 0;
348 		if (ASN1_time_tm_cmp(&tm_this, &tm_tmp) > 0) {
349 			OCSPerror(OCSP_R_STATUS_NOT_YET_VALID);
350 			return 0;
351 		}
352 
353 		/*
354 		 * If maxsec specified check thisUpdate is not more than maxsec
355 		 * in the past
356 		 */
357 		if (maxsec >= 0) {
358 			t_tmp = t_now - maxsec;
359 			if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
360 				return 0;
361 			if (ASN1_time_tm_cmp(&tm_this, &tm_tmp) < 0) {
362 				OCSPerror(OCSP_R_STATUS_TOO_OLD);
363 				return 0;
364 			}
365 		}
366 	}
367 
368 	if (!nextupd)
369 		return 1;
370 
371 	/* Check nextUpdate is valid and not more than nsec in the past */
372 	if (ASN1_time_parse(nextupd->data, nextupd->length, &tm_next,
373 	    V_ASN1_GENERALIZEDTIME) != V_ASN1_GENERALIZEDTIME) {
374 		OCSPerror(OCSP_R_ERROR_IN_NEXTUPDATE_FIELD);
375 		return 0;
376 	} else {
377 		t_tmp = t_now - nsec;
378 		if (gmtime_r(&t_tmp, &tm_tmp) == NULL)
379 			return 0;
380 		if (ASN1_time_tm_cmp(&tm_next, &tm_tmp) < 0) {
381 			OCSPerror(OCSP_R_STATUS_EXPIRED);
382 			return 0;
383 		}
384 	}
385 
386 	/* Also don't allow nextUpdate to precede thisUpdate */
387 	if (ASN1_time_tm_cmp(&tm_next, &tm_this) < 0) {
388 		OCSPerror(OCSP_R_NEXTUPDATE_BEFORE_THISUPDATE);
389 		return 0;
390 	}
391 
392 	return 1;
393 }
394 
395 const OCSP_CERTID *
OCSP_SINGLERESP_get0_id(const OCSP_SINGLERESP * single)396 OCSP_SINGLERESP_get0_id(const OCSP_SINGLERESP *single)
397 {
398 	return single->certId;
399 }
400