xref: /openbsd/usr.sbin/ocspcheck/ocspcheck.c (revision 3bef86f7)
1 /* $OpenBSD: ocspcheck.c,v 1.32 2023/11/13 11:46:24 tb Exp $ */
2 
3 /*
4  * Copyright (c) 2017,2020 Bob Beck <beck@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <arpa/inet.h>
20 #include <netinet/in.h>
21 #include <sys/socket.h>
22 #include <sys/stat.h>
23 
24 #include <err.h>
25 #include <fcntl.h>
26 #include <limits.h>
27 #include <netdb.h>
28 #include <poll.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <time.h>
33 #include <unistd.h>
34 
35 #include <openssl/err.h>
36 #include <openssl/ocsp.h>
37 #include <openssl/ssl.h>
38 
39 #include "http.h"
40 
41 #define MAXAGE_SEC (14*24*60*60)
42 #define JITTER_SEC (60)
43 #define OCSP_MAX_RESPONSE_SIZE (20480)
44 
45 typedef struct ocsp_request {
46 	STACK_OF(X509) *fullchain;
47 	OCSP_REQUEST *req;
48 	char *url;
49 	unsigned char *data;
50 	size_t size;
51 	int nonce;
52 } ocsp_request;
53 
54 int verbose;
55 #define vspew(fmt, ...) \
56 	do { if (verbose >= 1) fprintf(stderr, fmt, __VA_ARGS__); } while (0)
57 #define dspew(fmt, ...) \
58 	do { if (verbose >= 2) fprintf(stderr, fmt, __VA_ARGS__); } while (0)
59 
60 #define MAX_SERVERS_DNS 8
61 
62 struct addr {
63 	int	 family; /* 4 for PF_INET, 6 for PF_INET6 */
64 	char	 ip[INET6_ADDRSTRLEN];
65 };
66 
67 static ssize_t
68 host_dns(const char *s, struct addr vec[MAX_SERVERS_DNS])
69 {
70 	struct addrinfo		 hints, *res0, *res;
71 	int			 error;
72 	ssize_t			 vecsz;
73 	struct sockaddr		*sa;
74 
75 	memset(&hints, 0, sizeof(hints));
76 	hints.ai_family = PF_UNSPEC;
77 	hints.ai_socktype = SOCK_DGRAM; /* DUMMY */
78 
79 	error = getaddrinfo(s, NULL, &hints, &res0);
80 
81 	if (error == EAI_AGAIN ||
82 #ifdef EAI_NODATA
83 	    error == EAI_NODATA ||
84 #endif
85 	    error == EAI_NONAME)
86 		return 0;
87 
88 	if (error) {
89 		warnx("%s: parse error: %s", s, gai_strerror(error));
90 		return -1;
91 	}
92 
93 	for (vecsz = 0, res = res0;
94 	    res != NULL && vecsz < MAX_SERVERS_DNS;
95 	    res = res->ai_next) {
96 		if (res->ai_family != AF_INET &&
97 		    res->ai_family != AF_INET6)
98 			continue;
99 
100 		sa = res->ai_addr;
101 
102 		if (res->ai_family == AF_INET) {
103 			vec[vecsz].family = 4;
104 			inet_ntop(AF_INET,
105 			    &(((struct sockaddr_in *)sa)->sin_addr),
106 				vec[vecsz].ip, INET6_ADDRSTRLEN);
107 		} else {
108 			vec[vecsz].family = 6;
109 			inet_ntop(AF_INET6,
110 			    &(((struct sockaddr_in6 *)sa)->sin6_addr),
111 			    vec[vecsz].ip, INET6_ADDRSTRLEN);
112 		}
113 
114 		dspew("DNS returns %s for %s\n", vec[vecsz].ip, s);
115 		vecsz++;
116 	}
117 
118 	freeaddrinfo(res0);
119 	return vecsz;
120 }
121 
122 /*
123  * Extract the domain and port from a URL.
124  * The url must be formatted as schema://address[/stuff].
125  * This returns NULL on failure.
126  */
127 static char *
128 url2host(const char *host, short *port, char **path)
129 {
130 	char	*url, *ep;
131 
132 	/* We only understand HTTP and HTTPS. */
133 
134 	if (strncmp(host, "https://", 8) == 0) {
135 		*port = 443;
136 		if ((url = strdup(host + 8)) == NULL) {
137 			warn("strdup");
138 			return (NULL);
139 		}
140 	} else if (strncmp(host, "http://", 7) == 0) {
141 		*port = 80;
142 		if ((url = strdup(host + 7)) == NULL) {
143 			warn("strdup");
144 			return (NULL);
145 		}
146 	} else {
147 		warnx("%s: unknown schema", host);
148 		return (NULL);
149 	}
150 
151 	/* Terminate path part. */
152 
153 	if ((ep = strchr(url, '/')) != NULL) {
154 		*path = strdup(ep);
155 		*ep = '\0';
156 	} else
157 		*path = strdup("/");
158 
159 	if (*path == NULL) {
160 		warn("strdup");
161 		free(url);
162 		return (NULL);
163 	}
164 
165 	/* Check to see if there is a port in the url */
166 	if ((ep = strchr(url, ':')) != NULL) {
167 		const char *errstr;
168 		short pp;
169 		pp = strtonum(ep + 1, 1, SHRT_MAX, &errstr);
170 		if (errstr != NULL) {
171 			warnx("error parsing port from '%s': %s", url, errstr);
172 			free(url);
173 			free(*path);
174 			return NULL;
175 		}
176 		*port = pp;
177 		*ep = '\0';
178 	}
179 
180 	return (url);
181 }
182 
183 static time_t
184 parse_ocsp_time(ASN1_GENERALIZEDTIME *gt)
185 {
186 	struct tm tm;
187 	time_t rv = -1;
188 
189 	if (gt == NULL)
190 		return -1;
191 	/* RFC 6960 specifies that all times in OCSP must be GENERALIZEDTIME */
192 	if (!ASN1_GENERALIZEDTIME_check(gt))
193 		return -1;
194 	if (!ASN1_TIME_to_tm(gt, &tm))
195 		return -1;
196 	if ((rv = timegm(&tm)) == -1)
197 		return -1;
198 	return rv;
199 }
200 
201 static X509_STORE *
202 read_cacerts(const char *file, const char *dir)
203 {
204 	X509_STORE *store = NULL;
205 	X509_LOOKUP *lookup;
206 
207 	if (file == NULL && dir == NULL) {
208 		warnx("No CA certs to load");
209 		goto end;
210 	}
211 	if ((store = X509_STORE_new()) == NULL) {
212 		warnx("Malloc failed");
213 		goto end;
214 	}
215 	if (file != NULL) {
216 		if ((lookup = X509_STORE_add_lookup(store,
217 		    X509_LOOKUP_file())) == NULL) {
218 			warnx("Unable to load CA cert file");
219 			goto end;
220 		}
221 		if (!X509_LOOKUP_load_file(lookup, file, X509_FILETYPE_PEM)) {
222 			warnx("Unable to load CA certs from file %s", file);
223 			goto end;
224 		}
225 	}
226 	if (dir != NULL) {
227 		if ((lookup = X509_STORE_add_lookup(store,
228 		    X509_LOOKUP_hash_dir())) == NULL) {
229 			warnx("Unable to load CA cert directory");
230 			goto end;
231 		}
232 		if (!X509_LOOKUP_add_dir(lookup, dir, X509_FILETYPE_PEM)) {
233 			warnx("Unable to load CA certs from directory %s", dir);
234 			goto end;
235 		}
236 	}
237 	return store;
238 
239  end:
240 	X509_STORE_free(store);
241 	return NULL;
242 }
243 
244 static STACK_OF(X509) *
245 read_fullchain(const char *file, int *count)
246 {
247 	int i;
248 	BIO *bio;
249 	STACK_OF(X509_INFO) *xis = NULL;
250 	X509_INFO *xi;
251 	STACK_OF(X509) *rv = NULL;
252 
253 	*count = 0;
254 
255 	if ((bio = BIO_new_file(file, "r")) == NULL) {
256 		warn("Unable to read a certificate from %s", file);
257 		goto end;
258 	}
259 	if ((xis = PEM_X509_INFO_read_bio(bio, NULL, NULL, NULL)) == NULL) {
260 		warnx("Unable to read PEM format from %s", file);
261 		goto end;
262 	}
263 	if (sk_X509_INFO_num(xis) <= 0) {
264 		warnx("No certificates in file %s", file);
265 		goto end;
266 	}
267 	if ((rv = sk_X509_new_null()) == NULL) {
268 		warnx("malloc failed");
269 		goto end;
270 	}
271 
272 	for (i = 0; i < sk_X509_INFO_num(xis); i++) {
273 		xi = sk_X509_INFO_value(xis, i);
274 		if (xi->x509 == NULL)
275 			continue;
276 		if (!sk_X509_push(rv, xi->x509)) {
277 			warnx("unable to build x509 chain");
278 			sk_X509_pop_free(rv, X509_free);
279 			rv = NULL;
280 			goto end;
281 		}
282 		xi->x509 = NULL;
283 		(*count)++;
284 	}
285  end:
286 	BIO_free(bio);
287 	sk_X509_INFO_pop_free(xis, X509_INFO_free);
288 	return rv;
289 }
290 
291 static inline X509 *
292 cert_from_chain(STACK_OF(X509) *fullchain)
293 {
294 	return sk_X509_value(fullchain, 0);
295 }
296 
297 static const X509 *
298 issuer_from_chain(STACK_OF(X509) *fullchain)
299 {
300 	const X509 *cert;
301 	X509_NAME *issuer_name;
302 
303 	cert = cert_from_chain(fullchain);
304 	if ((issuer_name = X509_get_issuer_name(cert)) == NULL)
305 		return NULL;
306 
307 	return X509_find_by_subject(fullchain, issuer_name);
308 }
309 
310 static ocsp_request *
311 ocsp_request_new_from_cert(const char *cadir, char *file, int nonce)
312 {
313 	X509 *cert;
314 	int count = 0;
315 	OCSP_CERTID *id = NULL;
316 	ocsp_request *request = NULL;
317 	const EVP_MD *cert_id_md = NULL;
318 	const X509 *issuer;
319 	STACK_OF(OPENSSL_STRING) *urls = NULL;
320 
321 	if ((request = calloc(1, sizeof(ocsp_request))) == NULL) {
322 		warn("malloc");
323 		goto err;
324 	}
325 
326 	if ((request->req = OCSP_REQUEST_new()) == NULL)
327 		goto err;
328 
329 	request->fullchain = read_fullchain(file, &count);
330 	if (cadir == NULL) {
331 		/* Drop rpath from pledge, we don't need to read anymore */
332 		if (pledge("stdio inet dns", NULL) == -1)
333 			err(1, "pledge");
334 	}
335 	if (request->fullchain == NULL) {
336 		warnx("Unable to read cert chain from file %s", file);
337 		goto err;
338 	}
339 	if (count <= 1) {
340 		warnx("File %s does not contain a cert chain", file);
341 		goto err;
342 	}
343 	if ((cert = cert_from_chain(request->fullchain)) == NULL) {
344 		warnx("No certificate found in %s", file);
345 		goto err;
346 	}
347 	if ((issuer = issuer_from_chain(request->fullchain)) == NULL) {
348 		warnx("Unable to find issuer for cert in %s", file);
349 		goto err;
350 	}
351 
352 	urls = X509_get1_ocsp(cert);
353 	if (urls == NULL || sk_OPENSSL_STRING_num(urls) <= 0) {
354 		warnx("Certificate in %s contains no OCSP url", file);
355 		goto err;
356 	}
357 	if ((request->url = strdup(sk_OPENSSL_STRING_value(urls, 0))) == NULL)
358 		goto err;
359 	X509_email_free(urls);
360 	urls = NULL;
361 
362 	cert_id_md = EVP_sha1(); /* XXX. This sucks but OCSP is poopy */
363 	if ((id = OCSP_cert_to_id(cert_id_md, cert, issuer)) == NULL) {
364 		warnx("Unable to get certificate id from cert in %s", file);
365 		goto err;
366 	}
367 	if (OCSP_request_add0_id(request->req, id) == NULL) {
368 		warnx("Unable to add certificate id to request");
369 		goto err;
370 	}
371 	id = NULL;
372 
373 	request->nonce = nonce;
374 	if (request->nonce)
375 		OCSP_request_add1_nonce(request->req, NULL, -1);
376 
377 	if ((request->size = i2d_OCSP_REQUEST(request->req,
378 	    &request->data)) <= 0) {
379 		warnx("Unable to encode ocsp request");
380 		goto err;
381 	}
382 	if (request->data == NULL) {
383 		warnx("Unable to allocate memory");
384 		goto err;
385 	}
386 	return request;
387 
388  err:
389 	if (request != NULL) {
390 		sk_X509_pop_free(request->fullchain, X509_free);
391 		free(request->url);
392 		OCSP_REQUEST_free(request->req);
393 		free(request->data);
394 	}
395 	X509_email_free(urls);
396 	OCSP_CERTID_free(id);
397 	free(request);
398 	return NULL;
399 }
400 
401 
402 int
403 validate_response(char *buf, size_t size, ocsp_request *request,
404     X509_STORE *store, char *host, char *file)
405 {
406 	ASN1_GENERALIZEDTIME *revtime = NULL, *thisupd = NULL, *nextupd = NULL;
407 	const unsigned char **p = (const unsigned char **)&buf;
408 	int status, cert_status = 0, crl_reason = 0;
409 	time_t now, rev_t = -1, this_t, next_t;
410 	OCSP_RESPONSE *resp = NULL;
411 	OCSP_BASICRESP *bresp = NULL;
412 	OCSP_CERTID *cid = NULL;
413 	const X509 *cert, *issuer;
414 	int ret = 0;
415 
416 	if ((cert = cert_from_chain(request->fullchain)) == NULL) {
417 		warnx("No certificate found in %s", file);
418 		goto err;
419 	}
420 	if ((issuer = issuer_from_chain(request->fullchain)) == NULL) {
421 		warnx("Unable to find certificate issuer for cert in %s", file);
422 		goto err;
423 	}
424 	if ((cid = OCSP_cert_to_id(NULL, cert, issuer)) == NULL) {
425 		warnx("Unable to get issuer cert/CID in %s", file);
426 		goto err;
427 	}
428 
429 	if ((resp = d2i_OCSP_RESPONSE(NULL, p, size)) == NULL) {
430 		warnx("OCSP response unserializable from host %s", host);
431 		goto err;
432 	}
433 
434 	if ((bresp = OCSP_response_get1_basic(resp)) == NULL) {
435 		warnx("Failed to load OCSP response from %s", host);
436 		goto err;
437 	}
438 
439 	if (OCSP_basic_verify(bresp, request->fullchain, store,
440 		OCSP_TRUSTOTHER) != 1) {
441 		warnx("OCSP verify failed from %s", host);
442 		goto err;
443 	}
444 	dspew("OCSP response signature validated from %s\n", host);
445 
446 	status = OCSP_response_status(resp);
447 	if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) {
448 		warnx("OCSP Failure: code %d (%s) from host %s",
449 		    status, OCSP_response_status_str(status), host);
450 		goto err;
451 	}
452 	dspew("OCSP response status %d from host %s\n", status, host);
453 
454 	/* Check the nonce if we sent one */
455 
456 	if (request->nonce) {
457 		if (OCSP_check_nonce(request->req, bresp) <= 0) {
458 			warnx("No OCSP nonce, or mismatch, from host %s", host);
459 			goto err;
460 		}
461 	}
462 
463 	if (OCSP_resp_find_status(bresp, cid, &cert_status, &crl_reason,
464 	    &revtime, &thisupd, &nextupd) != 1) {
465 		warnx("OCSP verify failed: no result for cert");
466 		goto err;
467 	}
468 
469 	if (revtime && (rev_t = parse_ocsp_time(revtime)) == -1) {
470 		warnx("Unable to parse revocation time in OCSP reply");
471 		goto err;
472 	}
473 	/*
474 	 * Belt and suspenders, Treat it as revoked if there is either
475 	 * a revocation time, or status revoked.
476 	 */
477 	if (rev_t != -1 || cert_status == V_OCSP_CERTSTATUS_REVOKED) {
478 		warnx("Invalid OCSP reply: certificate is revoked");
479 		if (rev_t != -1)
480 			warnx("Certificate revoked at: %s", ctime(&rev_t));
481 		goto err;
482 	}
483 	if ((this_t = parse_ocsp_time(thisupd)) == -1) {
484 		warnx("unable to parse this update time in OCSP reply");
485 		goto err;
486 	}
487 	if ((next_t = parse_ocsp_time(nextupd)) == -1) {
488 		warnx("unable to parse next update time in OCSP reply");
489 		goto err;
490 	}
491 
492 	/* Don't allow this update to precede next update */
493 	if (this_t >= next_t) {
494 		warnx("Invalid OCSP reply: this update >= next update");
495 		goto err;
496 	}
497 
498 	now = time(NULL);
499 	/*
500 	 * Check that this update is not more than JITTER seconds
501 	 * in the future.
502 	 */
503 	if (this_t > now + JITTER_SEC) {
504 		warnx("Invalid OCSP reply: this update is in the future at %s",
505 		    ctime(&this_t));
506 		goto err;
507 	}
508 
509 	/*
510 	 * Check that this update is not more than MAXSEC
511 	 * in the past.
512 	 */
513 	if (this_t < now - MAXAGE_SEC) {
514 		warnx("Invalid OCSP reply: this update is too old %s",
515 		    ctime(&this_t));
516 		goto err;
517 	}
518 
519 	/*
520 	 * Check that next update is still valid
521 	 */
522 	if (next_t < now - JITTER_SEC) {
523 		warnx("Invalid OCSP reply: reply has expired at %s",
524 		    ctime(&next_t));
525 		goto err;
526 	}
527 
528 	vspew("OCSP response validated from %s\n", host);
529 	vspew("	   This Update: %s", ctime(&this_t));
530 	vspew("	   Next Update: %s", ctime(&next_t));
531 	ret = 1;
532  err:
533 	OCSP_RESPONSE_free(resp);
534 	OCSP_BASICRESP_free(bresp);
535 	OCSP_CERTID_free(cid);
536 	return ret;
537 }
538 
539 static void
540 usage(void)
541 {
542 	fprintf(stderr,
543 	    "usage: ocspcheck [-Nv] [-C CAfile] [-i staplefile] "
544 	    "[-o staplefile] file\n");
545 	exit(1);
546 }
547 
548 int
549 main(int argc, char **argv)
550 {
551 	const char *cafile = NULL, *cadir = NULL;
552 	char *host = NULL, *path = NULL, *certfile = NULL, *outfile = NULL,
553 	    *instaple = NULL, *infile = NULL;
554 	struct addr addrs[MAX_SERVERS_DNS] = {{0}};
555 	struct source sources[MAX_SERVERS_DNS];
556 	int i, ch, staplefd = -1, infd = -1, nonce = 1;
557 	ocsp_request *request = NULL;
558 	size_t rescount, httphsz = 0, instaplesz = 0;
559 	struct httphead	*httph = NULL;
560 	struct httpget *hget;
561 	X509_STORE *castore;
562 	ssize_t written, w;
563 	short port;
564 
565 	while ((ch = getopt(argc, argv, "C:i:No:v")) != -1) {
566 		switch (ch) {
567 		case 'C':
568 			cafile = optarg;
569 			break;
570 		case 'N':
571 			nonce = 0;
572 			break;
573 		case 'o':
574 			outfile = optarg;
575 			break;
576 		case 'i':
577 			infile = optarg;
578 			break;
579 		case 'v':
580 			verbose++;
581 			break;
582 		default:
583 			usage();
584 		}
585 	}
586 	argc -= optind;
587 	argv += optind;
588 
589 	if (argc != 1 || (certfile = argv[0]) == NULL)
590 		usage();
591 
592 	if (outfile != NULL) {
593 		if (strcmp(outfile, "-") == 0)
594 			staplefd = STDOUT_FILENO;
595 		else
596 			staplefd = open(outfile, O_WRONLY|O_CREAT,
597 			    S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH);
598 		if (staplefd < 0)
599 			err(1, "Unable to open output file %s", outfile);
600 	}
601 
602 	if (infile != NULL) {
603 		if (strcmp(infile, "-") == 0)
604 			infd = STDIN_FILENO;
605 		else
606 			infd = open(infile, O_RDONLY);
607 		if (infd < 0)
608 			err(1, "Unable to open input file %s", infile);
609 		nonce = 0; /* Can't validate a nonce on a saved reply */
610 	}
611 
612 	if (cafile == NULL) {
613 		if (access(X509_get_default_cert_file(), R_OK) == 0)
614 			cafile = X509_get_default_cert_file();
615 		if (access(X509_get_default_cert_dir(), F_OK) == 0)
616 			cadir = X509_get_default_cert_dir();
617 	}
618 
619 	if (cafile != NULL) {
620 		if (unveil(cafile, "r") == -1)
621 			err(1, "unveil %s", cafile);
622 	}
623 	if (cadir != NULL) {
624 		if (unveil(cadir, "r") == -1)
625 			err(1, "unveil %s", cadir);
626 	}
627 	if (unveil(certfile, "r") == -1)
628 		err(1, "unveil %s", certfile);
629 
630 	if (pledge("stdio inet rpath dns", NULL) == -1)
631 		err(1, "pledge");
632 
633 	/*
634 	 * Load our certificate and keystore, and build up an
635 	 * OCSP request based on the full certificate chain
636 	 * we have been given to check.
637 	 */
638 	if ((castore = read_cacerts(cafile, cadir)) == NULL)
639 		exit(1);
640 	if ((request = ocsp_request_new_from_cert(cadir, certfile, nonce))
641 	    == NULL)
642 		exit(1);
643 
644 	dspew("Built an %zu byte ocsp request\n", request->size);
645 
646 	if ((host = url2host(request->url, &port, &path)) == NULL)
647 		errx(1, "Invalid OCSP url %s from %s", request->url,
648 		    certfile);
649 
650 	if (infd == -1) {
651 		/* Get a new OCSP response from the indicated server */
652 
653 		vspew("Using %s to host %s, port %d, path %s\n",
654 		    port == 443 ? "https" : "http", host, port, path);
655 
656 		rescount = host_dns(host, addrs);
657 		for (i = 0; i < rescount; i++) {
658 			sources[i].ip = addrs[i].ip;
659 			sources[i].family = addrs[i].family;
660 		}
661 
662 		/*
663 		 * Do an HTTP post to send our request to the OCSP
664 		 * server, and hopefully get an answer back
665 		 */
666 		hget = http_get(sources, rescount, host, port, path,
667 		    request->data, request->size);
668 		if (hget == NULL)
669 			errx(1, "http_get");
670 		/*
671 		 * Pledge minimally before fiddling with libcrypto init
672 		 * routines and parsing untrusted input from someone's OCSP
673 		 * server.
674 		 */
675 		if (cadir == NULL) {
676 			if (pledge("stdio", NULL) == -1)
677 				err(1, "pledge");
678 		} else {
679 			if (pledge("stdio rpath", NULL) == -1)
680 				err(1, "pledge");
681 		}
682 
683 		dspew("Server at %s returns:\n", host);
684 		for (i = 0; i < httphsz; i++)
685 			dspew("	  [%s]=[%s]\n", httph[i].key, httph[i].val);
686 		dspew("	  [Body]=[%zu bytes]\n", hget->bodypartsz);
687 		if (hget->bodypartsz <= 0)
688 			errx(1, "No body in reply from %s", host);
689 
690 		if (hget->code != 200)
691 			errx(1, "http reply code %d from %s", hget->code, host);
692 
693 		/*
694 		 * Validate the OCSP response we got back
695 		 */
696 		OPENSSL_add_all_algorithms_noconf();
697 		if (!validate_response(hget->bodypart, hget->bodypartsz,
698 			request, castore, host, certfile))
699 			exit(1);
700 		instaple = hget->bodypart;
701 		instaplesz = hget->bodypartsz;
702 	} else {
703 		size_t nr = 0;
704 		instaplesz = 0;
705 
706 		/*
707 		 * Pledge minimally before fiddling with libcrypto init
708 		 */
709 		if (cadir == NULL) {
710 			if (pledge("stdio", NULL) == -1)
711 				err(1, "pledge");
712 		} else {
713 			if (pledge("stdio rpath", NULL) == -1)
714 				err(1, "pledge");
715 		}
716 
717 		dspew("Using ocsp response saved in %s:\n", infile);
718 
719 		/* Use the existing OCSP response saved in infd */
720 		instaple = calloc(OCSP_MAX_RESPONSE_SIZE, 1);
721 		if (instaple) {
722 			while ((nr = read(infd, instaple + instaplesz,
723 			    OCSP_MAX_RESPONSE_SIZE - instaplesz)) != -1 &&
724 			    nr != 0)
725 				instaplesz += nr;
726 		}
727 		if (instaplesz == 0)
728 			exit(1);
729 		/*
730 		 * Validate the OCSP staple we read in.
731 		 */
732 		OPENSSL_add_all_algorithms_noconf();
733 		if (!validate_response(instaple, instaplesz,
734 			request, castore, host, certfile))
735 			exit(1);
736 	}
737 
738 	/*
739 	 * If we have been given a place to save a staple,
740 	 * write out the DER format response to the staplefd
741 	 */
742 	if (staplefd >= 0) {
743 		while (ftruncate(staplefd, 0) < 0) {
744 			if (errno == EINVAL)
745 				break;
746 			if (errno != EINTR && errno != EAGAIN)
747 				err(1, "Write of OCSP response failed");
748 		}
749 		written = 0;
750 		while (written < instaplesz) {
751 			w = write(staplefd, instaple + written,
752 			    instaplesz - written);
753 			if (w == -1) {
754 				if (errno != EINTR && errno != EAGAIN)
755 					err(1, "Write of OCSP response failed");
756 			} else
757 				written += w;
758 		}
759 		close(staplefd);
760 	}
761 	exit(0);
762 }
763