xref: /openbsd/usr.sbin/ocspcheck/ocspcheck.c (revision ddff58c9)
1 /* $OpenBSD: ocspcheck.c,v 1.34 2024/12/04 07:58:51 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/posix_time.h>
38 #include <openssl/ssl.h>
39 
40 #include "http.h"
41 
42 #define MAXAGE_SEC (14*24*60*60)
43 #define JITTER_SEC (60)
44 #define OCSP_MAX_RESPONSE_SIZE (20480)
45 
46 typedef struct ocsp_request {
47 	STACK_OF(X509) *fullchain;
48 	OCSP_REQUEST *req;
49 	char *url;
50 	unsigned char *data;
51 	size_t size;
52 	int nonce;
53 } ocsp_request;
54 
55 int verbose;
56 #define vspew(fmt, ...) \
57 	do { if (verbose >= 1) fprintf(stderr, fmt, __VA_ARGS__); } while (0)
58 #define dspew(fmt, ...) \
59 	do { if (verbose >= 2) fprintf(stderr, fmt, __VA_ARGS__); } while (0)
60 
61 #define MAX_SERVERS_DNS 8
62 
63 struct addr {
64 	int	 family; /* 4 for PF_INET, 6 for PF_INET6 */
65 	char	 ip[INET6_ADDRSTRLEN];
66 };
67 
68 static ssize_t
host_dns(const char * s,struct addr vec[MAX_SERVERS_DNS])69 host_dns(const char *s, struct addr vec[MAX_SERVERS_DNS])
70 {
71 	struct addrinfo		 hints, *res0, *res;
72 	int			 error;
73 	ssize_t			 vecsz;
74 	struct sockaddr		*sa;
75 
76 	memset(&hints, 0, sizeof(hints));
77 	hints.ai_family = PF_UNSPEC;
78 	hints.ai_socktype = SOCK_DGRAM; /* DUMMY */
79 
80 	error = getaddrinfo(s, NULL, &hints, &res0);
81 
82 	if (error == EAI_AGAIN ||
83 #ifdef EAI_NODATA
84 	    error == EAI_NODATA ||
85 #endif
86 	    error == EAI_NONAME)
87 		return 0;
88 
89 	if (error) {
90 		warnx("%s: parse error: %s", s, gai_strerror(error));
91 		return -1;
92 	}
93 
94 	for (vecsz = 0, res = res0;
95 	    res != NULL && vecsz < MAX_SERVERS_DNS;
96 	    res = res->ai_next) {
97 		if (res->ai_family != AF_INET &&
98 		    res->ai_family != AF_INET6)
99 			continue;
100 
101 		sa = res->ai_addr;
102 
103 		if (res->ai_family == AF_INET) {
104 			vec[vecsz].family = 4;
105 			inet_ntop(AF_INET,
106 			    &(((struct sockaddr_in *)sa)->sin_addr),
107 				vec[vecsz].ip, INET6_ADDRSTRLEN);
108 		} else {
109 			vec[vecsz].family = 6;
110 			inet_ntop(AF_INET6,
111 			    &(((struct sockaddr_in6 *)sa)->sin6_addr),
112 			    vec[vecsz].ip, INET6_ADDRSTRLEN);
113 		}
114 
115 		dspew("DNS returns %s for %s\n", vec[vecsz].ip, s);
116 		vecsz++;
117 	}
118 
119 	freeaddrinfo(res0);
120 	return vecsz;
121 }
122 
123 /*
124  * Extract the domain and port from a URL.
125  * The url must be formatted as schema://address[/stuff].
126  * This returns NULL on failure.
127  */
128 static char *
url2host(const char * host,short * port,char ** path)129 url2host(const char *host, short *port, char **path)
130 {
131 	char	*url, *ep;
132 
133 	/* We only understand HTTP and HTTPS. */
134 
135 	if (strncmp(host, "https://", 8) == 0) {
136 		*port = 443;
137 		if ((url = strdup(host + 8)) == NULL) {
138 			warn("strdup");
139 			return (NULL);
140 		}
141 	} else if (strncmp(host, "http://", 7) == 0) {
142 		*port = 80;
143 		if ((url = strdup(host + 7)) == NULL) {
144 			warn("strdup");
145 			return (NULL);
146 		}
147 	} else {
148 		warnx("%s: unknown schema", host);
149 		return (NULL);
150 	}
151 
152 	/* Terminate path part. */
153 
154 	if ((ep = strchr(url, '/')) != NULL) {
155 		*path = strdup(ep);
156 		*ep = '\0';
157 	} else
158 		*path = strdup("/");
159 
160 	if (*path == NULL) {
161 		warn("strdup");
162 		free(url);
163 		return (NULL);
164 	}
165 
166 	/* Check to see if there is a port in the url */
167 	if ((ep = strchr(url, ':')) != NULL) {
168 		const char *errstr;
169 		short pp;
170 		pp = strtonum(ep + 1, 1, SHRT_MAX, &errstr);
171 		if (errstr != NULL) {
172 			warnx("error parsing port from '%s': %s", url, errstr);
173 			free(url);
174 			free(*path);
175 			return NULL;
176 		}
177 		*port = pp;
178 		*ep = '\0';
179 	}
180 
181 	return (url);
182 }
183 
184 static time_t
parse_ocsp_time(ASN1_GENERALIZEDTIME * gt)185 parse_ocsp_time(ASN1_GENERALIZEDTIME *gt)
186 {
187 	struct tm tm;
188 	time_t rv = -1;
189 
190 	if (gt == NULL)
191 		return -1;
192 	/* RFC 6960 specifies that all times in OCSP must be GENERALIZEDTIME */
193 	if (!ASN1_GENERALIZEDTIME_check(gt))
194 		return -1;
195 	if (!ASN1_TIME_to_tm(gt, &tm))
196 		return -1;
197 	if (!OPENSSL_timegm(&tm, &rv))
198 		return -1;
199 	return rv;
200 }
201 
202 static X509_STORE *
read_cacerts(const char * file,const char * dir)203 read_cacerts(const char *file, const char *dir)
204 {
205 	X509_STORE *store = NULL;
206 	X509_LOOKUP *lookup;
207 
208 	if (file == NULL && dir == NULL) {
209 		warnx("No CA certs to load");
210 		goto end;
211 	}
212 	if ((store = X509_STORE_new()) == NULL) {
213 		warnx("Malloc failed");
214 		goto end;
215 	}
216 	if (file != NULL) {
217 		if ((lookup = X509_STORE_add_lookup(store,
218 		    X509_LOOKUP_file())) == NULL) {
219 			warnx("Unable to load CA cert file");
220 			goto end;
221 		}
222 		if (!X509_LOOKUP_load_file(lookup, file, X509_FILETYPE_PEM)) {
223 			warnx("Unable to load CA certs from file %s", file);
224 			goto end;
225 		}
226 	}
227 	if (dir != NULL) {
228 		if ((lookup = X509_STORE_add_lookup(store,
229 		    X509_LOOKUP_hash_dir())) == NULL) {
230 			warnx("Unable to load CA cert directory");
231 			goto end;
232 		}
233 		if (!X509_LOOKUP_add_dir(lookup, dir, X509_FILETYPE_PEM)) {
234 			warnx("Unable to load CA certs from directory %s", dir);
235 			goto end;
236 		}
237 	}
238 	return store;
239 
240  end:
241 	X509_STORE_free(store);
242 	return NULL;
243 }
244 
STACK_OF(X509)245 static STACK_OF(X509) *
246 read_fullchain(const char *file, int *count)
247 {
248 	int i;
249 	BIO *bio;
250 	STACK_OF(X509_INFO) *xis = NULL;
251 	X509_INFO *xi;
252 	STACK_OF(X509) *rv = NULL;
253 
254 	*count = 0;
255 
256 	if ((bio = BIO_new_file(file, "r")) == NULL) {
257 		warn("Unable to read a certificate from %s", file);
258 		goto end;
259 	}
260 	if ((xis = PEM_X509_INFO_read_bio(bio, NULL, NULL, NULL)) == NULL) {
261 		warnx("Unable to read PEM format from %s", file);
262 		goto end;
263 	}
264 	if (sk_X509_INFO_num(xis) <= 0) {
265 		warnx("No certificates in file %s", file);
266 		goto end;
267 	}
268 	if ((rv = sk_X509_new_null()) == NULL) {
269 		warnx("malloc failed");
270 		goto end;
271 	}
272 
273 	for (i = 0; i < sk_X509_INFO_num(xis); i++) {
274 		xi = sk_X509_INFO_value(xis, i);
275 		if (xi->x509 == NULL)
276 			continue;
277 		if (!sk_X509_push(rv, xi->x509)) {
278 			warnx("unable to build x509 chain");
279 			sk_X509_pop_free(rv, X509_free);
280 			rv = NULL;
281 			goto end;
282 		}
283 		xi->x509 = NULL;
284 		(*count)++;
285 	}
286  end:
287 	BIO_free(bio);
288 	sk_X509_INFO_pop_free(xis, X509_INFO_free);
289 	return rv;
290 }
291 
292 static inline X509 *
cert_from_chain(STACK_OF (X509)* fullchain)293 cert_from_chain(STACK_OF(X509) *fullchain)
294 {
295 	return sk_X509_value(fullchain, 0);
296 }
297 
298 static const X509 *
issuer_from_chain(STACK_OF (X509)* fullchain)299 issuer_from_chain(STACK_OF(X509) *fullchain)
300 {
301 	const X509 *cert;
302 	X509_NAME *issuer_name;
303 
304 	cert = cert_from_chain(fullchain);
305 	if ((issuer_name = X509_get_issuer_name(cert)) == NULL)
306 		return NULL;
307 
308 	return X509_find_by_subject(fullchain, issuer_name);
309 }
310 
311 static ocsp_request *
ocsp_request_new_from_cert(const char * cadir,char * file,int nonce)312 ocsp_request_new_from_cert(const char *cadir, char *file, int nonce)
313 {
314 	X509 *cert;
315 	int count = 0;
316 	OCSP_CERTID *id = NULL;
317 	ocsp_request *request = NULL;
318 	const EVP_MD *cert_id_md = NULL;
319 	const X509 *issuer;
320 	STACK_OF(OPENSSL_STRING) *urls = NULL;
321 
322 	if ((request = calloc(1, sizeof(ocsp_request))) == NULL) {
323 		warn("malloc");
324 		goto err;
325 	}
326 
327 	if ((request->req = OCSP_REQUEST_new()) == NULL)
328 		goto err;
329 
330 	request->fullchain = read_fullchain(file, &count);
331 	if (cadir == NULL) {
332 		/* Drop rpath from pledge, we don't need to read anymore */
333 		if (pledge("stdio inet dns", NULL) == -1)
334 			err(1, "pledge");
335 	}
336 	if (request->fullchain == NULL) {
337 		warnx("Unable to read cert chain from file %s", file);
338 		goto err;
339 	}
340 	if (count <= 1) {
341 		warnx("File %s does not contain a cert chain", file);
342 		goto err;
343 	}
344 	if ((cert = cert_from_chain(request->fullchain)) == NULL) {
345 		warnx("No certificate found in %s", file);
346 		goto err;
347 	}
348 	if ((issuer = issuer_from_chain(request->fullchain)) == NULL) {
349 		warnx("Unable to find issuer for cert in %s", file);
350 		goto err;
351 	}
352 
353 	urls = X509_get1_ocsp(cert);
354 	if (urls == NULL || sk_OPENSSL_STRING_num(urls) <= 0) {
355 		warnx("Certificate in %s contains no OCSP url", file);
356 		goto err;
357 	}
358 	if ((request->url = strdup(sk_OPENSSL_STRING_value(urls, 0))) == NULL)
359 		goto err;
360 	X509_email_free(urls);
361 	urls = NULL;
362 
363 	cert_id_md = EVP_sha1(); /* XXX. This sucks but OCSP is poopy */
364 	if ((id = OCSP_cert_to_id(cert_id_md, cert, issuer)) == NULL) {
365 		warnx("Unable to get certificate id from cert in %s", file);
366 		goto err;
367 	}
368 	if (OCSP_request_add0_id(request->req, id) == NULL) {
369 		warnx("Unable to add certificate id to request");
370 		goto err;
371 	}
372 	id = NULL;
373 
374 	request->nonce = nonce;
375 	if (request->nonce)
376 		OCSP_request_add1_nonce(request->req, NULL, -1);
377 
378 	if ((request->size = i2d_OCSP_REQUEST(request->req,
379 	    &request->data)) <= 0) {
380 		warnx("Unable to encode ocsp request");
381 		goto err;
382 	}
383 	if (request->data == NULL) {
384 		warnx("Unable to allocate memory");
385 		goto err;
386 	}
387 	return request;
388 
389  err:
390 	if (request != NULL) {
391 		sk_X509_pop_free(request->fullchain, X509_free);
392 		free(request->url);
393 		OCSP_REQUEST_free(request->req);
394 		free(request->data);
395 	}
396 	X509_email_free(urls);
397 	OCSP_CERTID_free(id);
398 	free(request);
399 	return NULL;
400 }
401 
402 
403 int
validate_response(char * buf,size_t size,ocsp_request * request,X509_STORE * store,char * host,char * file)404 validate_response(char *buf, size_t size, ocsp_request *request,
405     X509_STORE *store, char *host, char *file)
406 {
407 	ASN1_GENERALIZEDTIME *revtime = NULL, *thisupd = NULL, *nextupd = NULL;
408 	const unsigned char **p = (const unsigned char **)&buf;
409 	int status, cert_status = 0, crl_reason = 0;
410 	time_t now, rev_t = -1, this_t, next_t;
411 	OCSP_RESPONSE *resp = NULL;
412 	OCSP_BASICRESP *bresp = NULL;
413 	OCSP_CERTID *cid = NULL;
414 	const X509 *cert, *issuer;
415 	int ret = 0;
416 
417 	if ((cert = cert_from_chain(request->fullchain)) == NULL) {
418 		warnx("No certificate found in %s", file);
419 		goto err;
420 	}
421 	if ((issuer = issuer_from_chain(request->fullchain)) == NULL) {
422 		warnx("Unable to find certificate issuer for cert in %s", file);
423 		goto err;
424 	}
425 	if ((cid = OCSP_cert_to_id(NULL, cert, issuer)) == NULL) {
426 		warnx("Unable to get issuer cert/CID in %s", file);
427 		goto err;
428 	}
429 
430 	if ((resp = d2i_OCSP_RESPONSE(NULL, p, size)) == NULL) {
431 		warnx("OCSP response unserializable from host %s", host);
432 		goto err;
433 	}
434 
435 	if ((bresp = OCSP_response_get1_basic(resp)) == NULL) {
436 		warnx("Failed to load OCSP response from %s", host);
437 		goto err;
438 	}
439 
440 	if (OCSP_basic_verify(bresp, request->fullchain, store,
441 		OCSP_TRUSTOTHER) != 1) {
442 		warnx("OCSP verify failed from %s", host);
443 		goto err;
444 	}
445 	dspew("OCSP response signature validated from %s\n", host);
446 
447 	status = OCSP_response_status(resp);
448 	if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) {
449 		warnx("OCSP Failure: code %d (%s) from host %s",
450 		    status, OCSP_response_status_str(status), host);
451 		goto err;
452 	}
453 	dspew("OCSP response status %d from host %s\n", status, host);
454 
455 	/* Check the nonce if we sent one */
456 
457 	if (request->nonce) {
458 		if (OCSP_check_nonce(request->req, bresp) <= 0) {
459 			warnx("No OCSP nonce, or mismatch, from host %s", host);
460 			goto err;
461 		}
462 	}
463 
464 	if (OCSP_resp_find_status(bresp, cid, &cert_status, &crl_reason,
465 	    &revtime, &thisupd, &nextupd) != 1) {
466 		warnx("OCSP verify failed: no result for cert");
467 		goto err;
468 	}
469 
470 	if (revtime && (rev_t = parse_ocsp_time(revtime)) == -1) {
471 		warnx("Unable to parse revocation time in OCSP reply");
472 		goto err;
473 	}
474 	/*
475 	 * Belt and suspenders, Treat it as revoked if there is either
476 	 * a revocation time, or status revoked.
477 	 */
478 	if (rev_t != -1 || cert_status == V_OCSP_CERTSTATUS_REVOKED) {
479 		warnx("Invalid OCSP reply: certificate is revoked");
480 		if (rev_t != -1)
481 			warnx("Certificate revoked at: %s", ctime(&rev_t));
482 		goto err;
483 	}
484 	if ((this_t = parse_ocsp_time(thisupd)) == -1) {
485 		warnx("unable to parse this update time in OCSP reply");
486 		goto err;
487 	}
488 	if ((next_t = parse_ocsp_time(nextupd)) == -1) {
489 		warnx("unable to parse next update time in OCSP reply");
490 		goto err;
491 	}
492 
493 	/* Don't allow this update to precede next update */
494 	if (this_t >= next_t) {
495 		warnx("Invalid OCSP reply: this update >= next update");
496 		goto err;
497 	}
498 
499 	now = time(NULL);
500 	/*
501 	 * Check that this update is not more than JITTER seconds
502 	 * in the future.
503 	 */
504 	if (this_t > now + JITTER_SEC) {
505 		warnx("Invalid OCSP reply: this update is in the future at %s",
506 		    ctime(&this_t));
507 		goto err;
508 	}
509 
510 	/*
511 	 * Check that this update is not more than MAXSEC
512 	 * in the past.
513 	 */
514 	if (this_t < now - MAXAGE_SEC) {
515 		warnx("Invalid OCSP reply: this update is too old %s",
516 		    ctime(&this_t));
517 		goto err;
518 	}
519 
520 	/*
521 	 * Check that next update is still valid
522 	 */
523 	if (next_t < now - JITTER_SEC) {
524 		warnx("Invalid OCSP reply: reply has expired at %s",
525 		    ctime(&next_t));
526 		goto err;
527 	}
528 
529 	vspew("OCSP response validated from %s\n", host);
530 	vspew("	   This Update: %s", ctime(&this_t));
531 	vspew("	   Next Update: %s", ctime(&next_t));
532 	ret = 1;
533  err:
534 	OCSP_RESPONSE_free(resp);
535 	OCSP_BASICRESP_free(bresp);
536 	OCSP_CERTID_free(cid);
537 	return ret;
538 }
539 
540 static void
usage(void)541 usage(void)
542 {
543 	fprintf(stderr,
544 	    "usage: ocspcheck [-Nv] [-C CAfile] [-i staplefile] "
545 	    "[-o staplefile] file\n");
546 	exit(1);
547 }
548 
549 int
main(int argc,char ** argv)550 main(int argc, char **argv)
551 {
552 	const char *cafile = NULL, *cadir = NULL;
553 	char *host = NULL, *path = NULL, *certfile = NULL, *outfile = NULL,
554 	    *instaple = NULL, *infile = NULL;
555 	struct addr addrs[MAX_SERVERS_DNS] = {{0}};
556 	struct source sources[MAX_SERVERS_DNS];
557 	int i, ch, staplefd = -1, infd = -1, nonce = 1;
558 	ocsp_request *request = NULL;
559 	size_t rescount, instaplesz = 0;
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 < hget->headsz; i++)
685 			dspew("   [%s]=[%s]\n", hget->head[i].key, hget->head[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