1 /* $Id: http.c,v 1.32 2022/12/14 18:32:26 florian Exp $ */
2 /*
3 * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <sys/types.h>
19 #include <sys/socket.h>
20
21 #include <arpa/inet.h>
22 #include <netinet/in.h>
23
24 #include <ctype.h>
25 #include <err.h>
26 #include <limits.h>
27 #include <netdb.h>
28 #include <stdio.h>
29 #include <stdint.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <tls.h>
33 #include <unistd.h>
34
35 #include "http.h"
36 #include "extern.h"
37
38 /*
39 * A buffer for transferring HTTP/S data.
40 */
41 struct httpxfer {
42 char *hbuf; /* header transfer buffer */
43 size_t hbufsz; /* header buffer size */
44 int headok; /* header has been parsed */
45 char *bbuf; /* body transfer buffer */
46 size_t bbufsz; /* body buffer size */
47 int bodyok; /* body has been parsed */
48 char *headbuf; /* lookaside buffer for headers */
49 struct httphead *head; /* parsed headers */
50 size_t headsz; /* number of headers */
51 };
52
53 /*
54 * An HTTP/S connection object.
55 */
56 struct http {
57 int fd; /* connected socket */
58 short port; /* port number */
59 struct source src; /* endpoint (raw) host */
60 char *path; /* path to request */
61 char *host; /* name of endpoint host */
62 struct tls *ctx; /* if TLS */
63 writefp writer; /* write function */
64 readfp reader; /* read function */
65 };
66
67 struct tls_config *tlscfg;
68
69 static ssize_t
dosysread(char * buf,size_t sz,const struct http * http)70 dosysread(char *buf, size_t sz, const struct http *http)
71 {
72 ssize_t rc;
73
74 rc = read(http->fd, buf, sz);
75 if (rc == -1)
76 warn("%s: read", http->src.ip);
77 return rc;
78 }
79
80 static ssize_t
dosyswrite(const void * buf,size_t sz,const struct http * http)81 dosyswrite(const void *buf, size_t sz, const struct http *http)
82 {
83 ssize_t rc;
84
85 rc = write(http->fd, buf, sz);
86 if (rc == -1)
87 warn("%s: write", http->src.ip);
88 return rc;
89 }
90
91 static ssize_t
dotlsread(char * buf,size_t sz,const struct http * http)92 dotlsread(char *buf, size_t sz, const struct http *http)
93 {
94 ssize_t rc;
95
96 do {
97 rc = tls_read(http->ctx, buf, sz);
98 } while (rc == TLS_WANT_POLLIN || rc == TLS_WANT_POLLOUT);
99
100 if (rc == -1)
101 warnx("%s: tls_read: %s", http->src.ip,
102 tls_error(http->ctx));
103 return rc;
104 }
105
106 static ssize_t
dotlswrite(const void * buf,size_t sz,const struct http * http)107 dotlswrite(const void *buf, size_t sz, const struct http *http)
108 {
109 ssize_t rc;
110
111 do {
112 rc = tls_write(http->ctx, buf, sz);
113 } while (rc == TLS_WANT_POLLIN || rc == TLS_WANT_POLLOUT);
114
115 if (rc == -1)
116 warnx("%s: tls_write: %s", http->src.ip,
117 tls_error(http->ctx));
118 return rc;
119 }
120
121 int
http_init(void)122 http_init(void)
123 {
124 if (tlscfg != NULL)
125 return 0;
126
127 tlscfg = tls_config_new();
128 if (tlscfg == NULL) {
129 warn("tls_config_new");
130 goto err;
131 }
132
133 if (tls_config_set_ca_file(tlscfg, tls_default_ca_cert_file()) == -1) {
134 warn("tls_config_set_ca_file: %s", tls_config_error(tlscfg));
135 goto err;
136 }
137
138 return 0;
139
140 err:
141 tls_config_free(tlscfg);
142 tlscfg = NULL;
143
144 return -1;
145 }
146
147 static ssize_t
http_read(char * buf,size_t sz,const struct http * http)148 http_read(char *buf, size_t sz, const struct http *http)
149 {
150 ssize_t ssz, xfer;
151
152 xfer = 0;
153 do {
154 if ((ssz = http->reader(buf, sz, http)) < 0)
155 return -1;
156 if (ssz == 0)
157 break;
158 xfer += ssz;
159 sz -= ssz;
160 buf += ssz;
161 } while (ssz > 0 && sz > 0);
162
163 return xfer;
164 }
165
166 static int
http_write(const char * buf,size_t sz,const struct http * http)167 http_write(const char *buf, size_t sz, const struct http *http)
168 {
169 ssize_t ssz, xfer;
170
171 xfer = sz;
172 while (sz > 0) {
173 if ((ssz = http->writer(buf, sz, http)) < 0)
174 return -1;
175 sz -= ssz;
176 buf += (size_t)ssz;
177 }
178 return xfer;
179 }
180
181 void
http_disconnect(struct http * http)182 http_disconnect(struct http *http)
183 {
184 int rc;
185
186 if (http->ctx != NULL) {
187 /* TLS connection. */
188 do {
189 rc = tls_close(http->ctx);
190 } while (rc == TLS_WANT_POLLIN || rc == TLS_WANT_POLLOUT);
191
192 tls_free(http->ctx);
193 }
194 if (http->fd != -1) {
195 if (close(http->fd) == -1)
196 warn("%s: close", http->src.ip);
197 }
198
199 http->fd = -1;
200 http->ctx = NULL;
201 }
202
203 void
http_free(struct http * http)204 http_free(struct http *http)
205 {
206
207 if (http == NULL)
208 return;
209 http_disconnect(http);
210 free(http->host);
211 free(http->path);
212 free(http->src.ip);
213 free(http);
214 }
215
216 struct http *
http_alloc(const struct source * addrs,size_t addrsz,const char * host,short port,const char * path)217 http_alloc(const struct source *addrs, size_t addrsz,
218 const char *host, short port, const char *path)
219 {
220 struct sockaddr_storage ss;
221 int family, fd, c;
222 socklen_t len;
223 size_t cur, i = 0;
224 struct http *http;
225
226 /* Do this while we still have addresses to connect. */
227 again:
228 if (i == addrsz)
229 return NULL;
230 cur = i++;
231
232 /* Convert to PF_INET or PF_INET6 address from string. */
233
234 memset(&ss, 0, sizeof(struct sockaddr_storage));
235
236 if (addrs[cur].family == 4) {
237 family = PF_INET;
238 ((struct sockaddr_in *)&ss)->sin_family = AF_INET;
239 ((struct sockaddr_in *)&ss)->sin_port = htons(port);
240 c = inet_pton(AF_INET, addrs[cur].ip,
241 &((struct sockaddr_in *)&ss)->sin_addr);
242 len = sizeof(struct sockaddr_in);
243 } else if (addrs[cur].family == 6) {
244 family = PF_INET6;
245 ((struct sockaddr_in6 *)&ss)->sin6_family = AF_INET6;
246 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(port);
247 c = inet_pton(AF_INET6, addrs[cur].ip,
248 &((struct sockaddr_in6 *)&ss)->sin6_addr);
249 len = sizeof(struct sockaddr_in6);
250 } else {
251 warnx("%s: unknown family", addrs[cur].ip);
252 goto again;
253 }
254
255 if (c < 0) {
256 warn("%s: inet_ntop", addrs[cur].ip);
257 goto again;
258 } else if (c == 0) {
259 warnx("%s: inet_ntop", addrs[cur].ip);
260 goto again;
261 }
262
263 /* Create socket and connect. */
264
265 fd = socket(family, SOCK_STREAM, 0);
266 if (fd == -1) {
267 warn("%s: socket", addrs[cur].ip);
268 goto again;
269 } else if (connect(fd, (struct sockaddr *)&ss, len) == -1) {
270 warn("%s: connect", addrs[cur].ip);
271 close(fd);
272 goto again;
273 }
274
275 /* Allocate the communicator. */
276
277 http = calloc(1, sizeof(struct http));
278 if (http == NULL) {
279 warn("calloc");
280 close(fd);
281 return NULL;
282 }
283 http->fd = fd;
284 http->port = port;
285 http->src.family = addrs[cur].family;
286 http->src.ip = strdup(addrs[cur].ip);
287 http->host = strdup(host);
288 http->path = strdup(path);
289 if (http->src.ip == NULL || http->host == NULL || http->path == NULL) {
290 warn("strdup");
291 goto err;
292 }
293
294 /* If necessary, do our TLS setup. */
295
296 if (port != 443) {
297 http->writer = dosyswrite;
298 http->reader = dosysread;
299 return http;
300 }
301
302 http->writer = dotlswrite;
303 http->reader = dotlsread;
304
305 if ((http->ctx = tls_client()) == NULL) {
306 warn("tls_client");
307 goto err;
308 } else if (tls_configure(http->ctx, tlscfg) == -1) {
309 warnx("%s: tls_configure: %s",
310 http->src.ip, tls_error(http->ctx));
311 goto err;
312 }
313
314 if (tls_connect_socket(http->ctx, http->fd, http->host) != 0) {
315 warnx("%s: tls_connect_socket: %s, %s", http->src.ip,
316 http->host, tls_error(http->ctx));
317 goto err;
318 }
319
320 return http;
321 err:
322 http_free(http);
323 return NULL;
324 }
325
326 struct httpxfer *
http_open(const struct http * http,int headreq,const void * p,size_t psz)327 http_open(const struct http *http, int headreq, const void *p, size_t psz)
328 {
329 char *req;
330 int c;
331 struct httpxfer *trans;
332
333 if (p == NULL) {
334 if (headreq)
335 c = asprintf(&req,
336 "HEAD %s HTTP/1.0\r\n"
337 "Host: %s\r\n"
338 "User-Agent: OpenBSD-acme-client\r\n"
339 "\r\n",
340 http->path, http->host);
341 else
342 c = asprintf(&req,
343 "GET %s HTTP/1.0\r\n"
344 "Host: %s\r\n"
345 "User-Agent: OpenBSD-acme-client\r\n"
346 "\r\n",
347 http->path, http->host);
348 } else {
349 c = asprintf(&req,
350 "POST %s HTTP/1.0\r\n"
351 "Host: %s\r\n"
352 "Content-Length: %zu\r\n"
353 "Content-Type: application/jose+json\r\n"
354 "User-Agent: OpenBSD-acme-client\r\n"
355 "\r\n",
356 http->path, http->host, psz);
357 }
358
359 if (c == -1) {
360 warn("asprintf");
361 return NULL;
362 } else if (!http_write(req, c, http)) {
363 free(req);
364 return NULL;
365 } else if (p != NULL && !http_write(p, psz, http)) {
366 free(req);
367 return NULL;
368 }
369
370 free(req);
371
372 trans = calloc(1, sizeof(struct httpxfer));
373 if (trans == NULL)
374 warn("calloc");
375 return trans;
376 }
377
378 void
http_close(struct httpxfer * x)379 http_close(struct httpxfer *x)
380 {
381
382 if (x == NULL)
383 return;
384 free(x->hbuf);
385 free(x->bbuf);
386 free(x->headbuf);
387 free(x->head);
388 free(x);
389 }
390
391 /*
392 * Read the HTTP body from the wire.
393 * If invoked multiple times, this will return the same pointer with the
394 * same data (or NULL, if the original invocation returned NULL).
395 * Returns NULL if read or allocation errors occur.
396 * You must not free the returned pointer.
397 */
398 char *
http_body_read(const struct http * http,struct httpxfer * trans,size_t * sz)399 http_body_read(const struct http *http, struct httpxfer *trans, size_t *sz)
400 {
401 char buf[BUFSIZ];
402 ssize_t ssz;
403 void *pp;
404 size_t szp;
405
406 if (sz == NULL)
407 sz = &szp;
408
409 /* Have we already parsed this? */
410
411 if (trans->bodyok > 0) {
412 *sz = trans->bbufsz;
413 return trans->bbuf;
414 } else if (trans->bodyok < 0)
415 return NULL;
416
417 *sz = 0;
418 trans->bodyok = -1;
419
420 do {
421 /* If less than sizeof(buf), at EOF. */
422 if ((ssz = http_read(buf, sizeof(buf), http)) < 0)
423 return NULL;
424 else if (ssz == 0)
425 break;
426 pp = recallocarray(trans->bbuf,
427 trans->bbufsz, trans->bbufsz + ssz, 1);
428 if (pp == NULL) {
429 warn("recallocarray");
430 return NULL;
431 }
432 trans->bbuf = pp;
433 memcpy(trans->bbuf + trans->bbufsz, buf, ssz);
434 trans->bbufsz += ssz;
435 } while (ssz == sizeof(buf));
436
437 trans->bodyok = 1;
438 *sz = trans->bbufsz;
439 return trans->bbuf;
440 }
441
442 struct httphead *
http_head_get(const char * v,struct httphead * h,size_t hsz)443 http_head_get(const char *v, struct httphead *h, size_t hsz)
444 {
445 size_t i;
446
447 for (i = 0; i < hsz; i++) {
448 if (strcasecmp(h[i].key, v) == 0)
449 return &h[i];
450 }
451 return NULL;
452 }
453
454 /*
455 * Look through the headers and determine our HTTP code.
456 * This will return -1 on failure, otherwise the code.
457 */
458 int
http_head_status(const struct http * http,struct httphead * h,size_t sz)459 http_head_status(const struct http *http, struct httphead *h, size_t sz)
460 {
461 int rc;
462 unsigned int code;
463 struct httphead *st;
464
465 if ((st = http_head_get("Status", h, sz)) == NULL) {
466 warnx("%s: no status header", http->src.ip);
467 return -1;
468 }
469
470 rc = sscanf(st->val, "%*s %u %*s", &code);
471 if (rc < 0) {
472 warn("sscanf");
473 return -1;
474 } else if (rc != 1) {
475 warnx("%s: cannot convert status header", http->src.ip);
476 return -1;
477 }
478 return code;
479 }
480
481 /*
482 * Parse headers from the transfer.
483 * Malformed headers are skipped.
484 * A special "Status" header is added for the HTTP status line.
485 * This can only happen once http_head_read has been called with
486 * success.
487 * This can be invoked multiple times: it will only parse the headers
488 * once and after that it will just return the cache.
489 * You must not free the returned pointer.
490 * If the original header parse failed, or if memory allocation fails
491 * internally, this returns NULL.
492 */
493 struct httphead *
http_head_parse(const struct http * http,struct httpxfer * trans,size_t * sz)494 http_head_parse(const struct http *http, struct httpxfer *trans, size_t *sz)
495 {
496 size_t hsz, szp;
497 struct httphead *h;
498 char *cp, *ep, *ccp, *buf;
499
500 if (sz == NULL)
501 sz = &szp;
502
503 /*
504 * If we've already parsed the headers, return the
505 * previously-parsed buffer now.
506 * If we have errors on the stream, return NULL now.
507 */
508
509 if (trans->head != NULL) {
510 *sz = trans->headsz;
511 return trans->head;
512 } else if (trans->headok <= 0)
513 return NULL;
514
515 if ((buf = strdup(trans->hbuf)) == NULL) {
516 warn("strdup");
517 return NULL;
518 }
519 hsz = 0;
520 cp = buf;
521
522 do {
523 if ((cp = strstr(cp, "\r\n")) != NULL)
524 cp += 2;
525 hsz++;
526 } while (cp != NULL);
527
528 /*
529 * Allocate headers, then step through the data buffer, parsing
530 * out headers as we have them.
531 * We know at this point that the buffer is NUL-terminated in
532 * the usual way.
533 */
534
535 h = calloc(hsz, sizeof(struct httphead));
536 if (h == NULL) {
537 warn("calloc");
538 free(buf);
539 return NULL;
540 }
541
542 *sz = hsz;
543 hsz = 0;
544 cp = buf;
545
546 do {
547 if ((ep = strstr(cp, "\r\n")) != NULL) {
548 *ep = '\0';
549 ep += 2;
550 }
551 if (hsz == 0) {
552 h[hsz].key = "Status";
553 h[hsz++].val = cp;
554 continue;
555 }
556
557 /* Skip bad headers. */
558 if ((ccp = strchr(cp, ':')) == NULL) {
559 warnx("%s: header without separator", http->src.ip);
560 continue;
561 }
562
563 *ccp++ = '\0';
564 while (isspace((unsigned char)*ccp))
565 ccp++;
566 h[hsz].key = cp;
567 h[hsz++].val = ccp;
568 } while ((cp = ep) != NULL);
569
570 trans->headbuf = buf;
571 trans->head = h;
572 trans->headsz = hsz;
573 return h;
574 }
575
576 /*
577 * Read the HTTP headers from the wire.
578 * If invoked multiple times, this will return the same pointer with the
579 * same data (or NULL, if the original invocation returned NULL).
580 * Returns NULL if read or allocation errors occur.
581 * You must not free the returned pointer.
582 */
583 char *
http_head_read(const struct http * http,struct httpxfer * trans,size_t * sz)584 http_head_read(const struct http *http, struct httpxfer *trans, size_t *sz)
585 {
586 char buf[BUFSIZ];
587 ssize_t ssz;
588 char *ep;
589 void *pp;
590 size_t szp;
591
592 if (sz == NULL)
593 sz = &szp;
594
595 /* Have we already parsed this? */
596
597 if (trans->headok > 0) {
598 *sz = trans->hbufsz;
599 return trans->hbuf;
600 } else if (trans->headok < 0)
601 return NULL;
602
603 *sz = 0;
604 ep = NULL;
605 trans->headok = -1;
606
607 /*
608 * Begin by reading by BUFSIZ blocks until we reach the header
609 * termination marker (two CRLFs).
610 * We might read into our body, but that's ok: we'll copy out
611 * the body parts into our body buffer afterward.
612 */
613
614 do {
615 /* If less than sizeof(buf), at EOF. */
616 if ((ssz = http_read(buf, sizeof(buf), http)) < 0)
617 return NULL;
618 else if (ssz == 0)
619 break;
620 pp = recallocarray(trans->hbuf,
621 trans->hbufsz, trans->hbufsz + ssz, 1);
622 if (pp == NULL) {
623 warn("recallocarray");
624 return NULL;
625 }
626 trans->hbuf = pp;
627 memcpy(trans->hbuf + trans->hbufsz, buf, ssz);
628 trans->hbufsz += ssz;
629 /* Search for end of headers marker. */
630 ep = memmem(trans->hbuf, trans->hbufsz, "\r\n\r\n", 4);
631 } while (ep == NULL && ssz == sizeof(buf));
632
633 if (ep == NULL) {
634 warnx("%s: partial transfer", http->src.ip);
635 return NULL;
636 }
637 *ep = '\0';
638
639 /*
640 * The header data is invalid if it has any binary characters in
641 * it: check that now.
642 * This is important because we want to guarantee that all
643 * header keys and pairs are properly NUL-terminated.
644 */
645
646 if (strlen(trans->hbuf) != (uintptr_t)(ep - trans->hbuf)) {
647 warnx("%s: binary data in header", http->src.ip);
648 return NULL;
649 }
650
651 /*
652 * Copy remaining buffer into body buffer.
653 */
654
655 ep += 4;
656 trans->bbufsz = (trans->hbuf + trans->hbufsz) - ep;
657 trans->bbuf = malloc(trans->bbufsz);
658 if (trans->bbuf == NULL) {
659 warn("malloc");
660 return NULL;
661 }
662 memcpy(trans->bbuf, ep, trans->bbufsz);
663
664 trans->headok = 1;
665 *sz = trans->hbufsz;
666 return trans->hbuf;
667 }
668
669 void
http_get_free(struct httpget * g)670 http_get_free(struct httpget *g)
671 {
672
673 if (g == NULL)
674 return;
675 http_close(g->xfer);
676 http_free(g->http);
677 free(g);
678 }
679
680 struct httpget *
http_get(const struct source * addrs,size_t addrsz,const char * domain,short port,const char * path,int headreq,const void * post,size_t postsz)681 http_get(const struct source *addrs, size_t addrsz, const char *domain,
682 short port, const char *path, int headreq, const void *post, size_t postsz)
683 {
684 struct http *h;
685 struct httpxfer *x;
686 struct httpget *g;
687 struct httphead *head;
688 size_t headsz, bodsz, headrsz;
689 int code;
690 char *bod, *headr;
691
692 h = http_alloc(addrs, addrsz, domain, port, path);
693 if (h == NULL)
694 return NULL;
695
696 if ((x = http_open(h, headreq, post, postsz)) == NULL) {
697 http_free(h);
698 return NULL;
699 } else if ((headr = http_head_read(h, x, &headrsz)) == NULL) {
700 http_close(x);
701 http_free(h);
702 return NULL;
703 } else if ((bod = http_body_read(h, x, &bodsz)) == NULL) {
704 http_close(x);
705 http_free(h);
706 return NULL;
707 }
708
709 http_disconnect(h);
710
711 if ((head = http_head_parse(h, x, &headsz)) == NULL) {
712 http_close(x);
713 http_free(h);
714 return NULL;
715 } else if ((code = http_head_status(h, head, headsz)) < 0) {
716 http_close(x);
717 http_free(h);
718 return NULL;
719 }
720
721 if ((g = calloc(1, sizeof(struct httpget))) == NULL) {
722 warn("calloc");
723 http_close(x);
724 http_free(h);
725 return NULL;
726 }
727
728 g->headpart = headr;
729 g->headpartsz = headrsz;
730 g->bodypart = bod;
731 g->bodypartsz = bodsz;
732 g->head = head;
733 g->headsz = headsz;
734 g->code = code;
735 g->xfer = x;
736 g->http = h;
737 return g;
738 }
739