xref: /freebsd/lib/libfetch/http.c (revision 67350cb56a69468c118bd4ccf6e361b7ebfa9eb4)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2000-2014 Dag-Erling Smørgrav
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer
12  *    in this position and unchanged.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 /*
35  * The following copyright applies to the base64 code:
36  *
37  *-
38  * Copyright 1997 Massachusetts Institute of Technology
39  *
40  * Permission to use, copy, modify, and distribute this software and
41  * its documentation for any purpose and without fee is hereby
42  * granted, provided that both the above copyright notice and this
43  * permission notice appear in all copies, that both the above
44  * copyright notice and this permission notice appear in all
45  * supporting documentation, and that the name of M.I.T. not be used
46  * in advertising or publicity pertaining to distribution of the
47  * software without specific, written prior permission.  M.I.T. makes
48  * no representations about the suitability of this software for any
49  * purpose.  It is provided "as is" without express or implied
50  * warranty.
51  *
52  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
53  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
54  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
55  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
56  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
57  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
58  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
59  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
60  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
61  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
62  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  */
65 
66 #include <sys/param.h>
67 #include <sys/socket.h>
68 #include <sys/time.h>
69 
70 #include <ctype.h>
71 #include <err.h>
72 #include <errno.h>
73 #include <locale.h>
74 #include <netdb.h>
75 #include <stdarg.h>
76 #include <stdio.h>
77 #include <stdlib.h>
78 #include <string.h>
79 #include <time.h>
80 #include <unistd.h>
81 
82 #ifdef WITH_SSL
83 #include <openssl/md5.h>
84 #define MD5Init(c) MD5_Init(c)
85 #define MD5Update(c, data, len) MD5_Update(c, data, len)
86 #define MD5Final(md, c) MD5_Final(md, c)
87 #else
88 #include <md5.h>
89 #endif
90 
91 #include <netinet/in.h>
92 #include <netinet/tcp.h>
93 
94 #include "fetch.h"
95 #include "common.h"
96 #include "httperr.h"
97 
98 /* Maximum number of redirects to follow */
99 #define MAX_REDIRECT 20
100 
101 /* Symbolic names for reply codes we care about */
102 #define HTTP_OK			200
103 #define HTTP_PARTIAL		206
104 #define HTTP_MOVED_PERM		301
105 #define HTTP_MOVED_TEMP		302
106 #define HTTP_SEE_OTHER		303
107 #define HTTP_NOT_MODIFIED	304
108 #define HTTP_USE_PROXY		305
109 #define HTTP_TEMP_REDIRECT	307
110 #define HTTP_PERM_REDIRECT	308
111 #define HTTP_NEED_AUTH		401
112 #define HTTP_NEED_PROXY_AUTH	407
113 #define HTTP_BAD_RANGE		416
114 #define HTTP_PROTOCOL_ERROR	999
115 
116 #define HTTP_REDIRECT(xyz) ((xyz) == HTTP_MOVED_PERM \
117 			    || (xyz) == HTTP_MOVED_TEMP \
118 			    || (xyz) == HTTP_TEMP_REDIRECT \
119 			    || (xyz) == HTTP_PERM_REDIRECT \
120 			    || (xyz) == HTTP_USE_PROXY \
121 			    || (xyz) == HTTP_SEE_OTHER)
122 
123 #define HTTP_ERROR(xyz) ((xyz) >= 400 && (xyz) <= 599)
124 
125 
126 /*****************************************************************************
127  * I/O functions for decoding chunked streams
128  */
129 
130 struct httpio
131 {
132 	conn_t		*conn;		/* connection */
133 	int		 chunked;	/* chunked mode */
134 	char		*buf;		/* chunk buffer */
135 	size_t		 bufsize;	/* size of chunk buffer */
136 	size_t		 buflen;	/* amount of data currently in buffer */
137 	size_t		 bufpos;	/* current read offset in buffer */
138 	int		 eof;		/* end-of-file flag */
139 	int		 error;		/* error flag */
140 	size_t		 chunksize;	/* remaining size of current chunk */
141 #ifndef NDEBUG
142 	size_t		 total;
143 #endif
144 };
145 
146 /*
147  * Get next chunk header
148  */
149 static int
150 http_new_chunk(struct httpio *io)
151 {
152 	char *p;
153 
154 	if (fetch_getln(io->conn) == -1)
155 		return (-1);
156 
157 	if (io->conn->buflen < 2 || !isxdigit((unsigned char)*io->conn->buf))
158 		return (-1);
159 
160 	for (p = io->conn->buf; *p && !isspace((unsigned char)*p); ++p) {
161 		if (*p == ';')
162 			break;
163 		if (!isxdigit((unsigned char)*p))
164 			return (-1);
165 		if (isdigit((unsigned char)*p)) {
166 			io->chunksize = io->chunksize * 16 +
167 			    *p - '0';
168 		} else {
169 			io->chunksize = io->chunksize * 16 +
170 			    10 + tolower((unsigned char)*p) - 'a';
171 		}
172 	}
173 
174 #ifndef NDEBUG
175 	if (fetchDebug) {
176 		io->total += io->chunksize;
177 		if (io->chunksize == 0)
178 			fprintf(stderr, "%s(): end of last chunk\n", __func__);
179 		else
180 			fprintf(stderr, "%s(): new chunk: %lu (%lu)\n",
181 			    __func__, (unsigned long)io->chunksize,
182 			    (unsigned long)io->total);
183 	}
184 #endif
185 
186 	return (io->chunksize);
187 }
188 
189 /*
190  * Grow the input buffer to at least len bytes
191  */
192 static inline int
193 http_growbuf(struct httpio *io, size_t len)
194 {
195 	char *tmp;
196 
197 	if (io->bufsize >= len)
198 		return (0);
199 
200 	if ((tmp = realloc(io->buf, len)) == NULL)
201 		return (-1);
202 	io->buf = tmp;
203 	io->bufsize = len;
204 	return (0);
205 }
206 
207 /*
208  * Fill the input buffer, do chunk decoding on the fly
209  */
210 static ssize_t
211 http_fillbuf(struct httpio *io, size_t len)
212 {
213 	ssize_t nbytes;
214 	char ch;
215 
216 	if (io->error)
217 		return (-1);
218 	if (io->eof)
219 		return (0);
220 
221 	/* not chunked: just fetch the requested amount */
222 	if (io->chunked == 0) {
223 		if (http_growbuf(io, len) == -1)
224 			return (-1);
225 		if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
226 			io->error = errno;
227 			return (-1);
228 		}
229 		io->buflen = nbytes;
230 		io->bufpos = 0;
231 		return (io->buflen);
232 	}
233 
234 	/* chunked, but we ran out: get the next chunk header */
235 	if (io->chunksize == 0) {
236 		switch (http_new_chunk(io)) {
237 		case -1:
238 			io->error = EPROTO;
239 			return (-1);
240 		case 0:
241 			io->eof = 1;
242 			return (0);
243 		}
244 	}
245 
246 	/* fetch the requested amount, but no more than the current chunk */
247 	if (len > io->chunksize)
248 		len = io->chunksize;
249 	if (http_growbuf(io, len) == -1)
250 		return (-1);
251 	if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
252 		io->error = errno;
253 		return (-1);
254 	}
255 	io->bufpos = 0;
256 	io->buflen = nbytes;
257 	io->chunksize -= nbytes;
258 
259 	if (io->chunksize == 0) {
260 		if (fetch_read(io->conn, &ch, 1) != 1 || ch != '\r' ||
261 		    fetch_read(io->conn, &ch, 1) != 1 || ch != '\n')
262 			return (-1);
263 	}
264 
265 	return (io->buflen);
266 }
267 
268 /*
269  * Read function
270  */
271 static int
272 http_readfn(void *v, char *buf, int len)
273 {
274 	struct httpio *io = (struct httpio *)v;
275 	int rlen;
276 
277 	if (io->error)
278 		return (-1);
279 	if (io->eof)
280 		return (0);
281 
282 	/* empty buffer */
283 	if (!io->buf || io->bufpos == io->buflen) {
284 		if ((rlen = http_fillbuf(io, len)) < 0) {
285 			if ((errno = io->error) == EINTR)
286 				io->error = 0;
287 			return (-1);
288 		} else if (rlen == 0) {
289 			return (0);
290 		}
291 	}
292 
293 	rlen = io->buflen - io->bufpos;
294 	if (len < rlen)
295 		rlen = len;
296 	memcpy(buf, io->buf + io->bufpos, rlen);
297 	io->bufpos += rlen;
298 	return (rlen);
299 }
300 
301 /*
302  * Write function
303  */
304 static int
305 http_writefn(void *v, const char *buf, int len)
306 {
307 	struct httpio *io = (struct httpio *)v;
308 
309 	return (fetch_write(io->conn, buf, len));
310 }
311 
312 /*
313  * Close function
314  */
315 static int
316 http_closefn(void *v)
317 {
318 	struct httpio *io = (struct httpio *)v;
319 	int r;
320 
321 	r = fetch_close(io->conn);
322 	if (io->buf)
323 		free(io->buf);
324 	free(io);
325 	return (r);
326 }
327 
328 /*
329  * Wrap a file descriptor up
330  */
331 static FILE *
332 http_funopen(conn_t *conn, int chunked)
333 {
334 	struct httpio *io;
335 	FILE *f;
336 
337 	if ((io = calloc(1, sizeof(*io))) == NULL) {
338 		fetch_syserr();
339 		return (NULL);
340 	}
341 	io->conn = conn;
342 	io->chunked = chunked;
343 	f = funopen(io, http_readfn, http_writefn, NULL, http_closefn);
344 	if (f == NULL) {
345 		fetch_syserr();
346 		free(io);
347 		return (NULL);
348 	}
349 	return (f);
350 }
351 
352 
353 /*****************************************************************************
354  * Helper functions for talking to the server and parsing its replies
355  */
356 
357 /* Header types */
358 typedef enum {
359 	hdr_syserror = -2,
360 	hdr_error = -1,
361 	hdr_end = 0,
362 	hdr_unknown = 1,
363 	hdr_content_length,
364 	hdr_content_range,
365 	hdr_last_modified,
366 	hdr_location,
367 	hdr_transfer_encoding,
368 	hdr_www_authenticate,
369 	hdr_proxy_authenticate,
370 } hdr_t;
371 
372 /* Names of interesting headers */
373 static struct {
374 	hdr_t		 num;
375 	const char	*name;
376 } hdr_names[] = {
377 	{ hdr_content_length,		"Content-Length" },
378 	{ hdr_content_range,		"Content-Range" },
379 	{ hdr_last_modified,		"Last-Modified" },
380 	{ hdr_location,			"Location" },
381 	{ hdr_transfer_encoding,	"Transfer-Encoding" },
382 	{ hdr_www_authenticate,		"WWW-Authenticate" },
383 	{ hdr_proxy_authenticate,	"Proxy-Authenticate" },
384 	{ hdr_unknown,			NULL },
385 };
386 
387 /*
388  * Send a formatted line; optionally echo to terminal
389  */
390 static int
391 http_cmd(conn_t *conn, const char *fmt, ...)
392 {
393 	va_list ap;
394 	size_t len;
395 	char *msg;
396 	int r;
397 
398 	va_start(ap, fmt);
399 	len = vasprintf(&msg, fmt, ap);
400 	va_end(ap);
401 
402 	if (msg == NULL) {
403 		errno = ENOMEM;
404 		fetch_syserr();
405 		return (-1);
406 	}
407 
408 	r = fetch_putln(conn, msg, len);
409 	free(msg);
410 
411 	if (r == -1) {
412 		fetch_syserr();
413 		return (-1);
414 	}
415 
416 	return (0);
417 }
418 
419 /*
420  * Get and parse status line
421  */
422 static int
423 http_get_reply(conn_t *conn)
424 {
425 	char *p;
426 
427 	if (fetch_getln(conn) == -1)
428 		return (-1);
429 	/*
430 	 * A valid status line looks like "HTTP/m.n xyz reason" where m
431 	 * and n are the major and minor protocol version numbers and xyz
432 	 * is the reply code.
433 	 * Unfortunately, there are servers out there (NCSA 1.5.1, to name
434 	 * just one) that do not send a version number, so we can't rely
435 	 * on finding one, but if we do, insist on it being 1.0 or 1.1.
436 	 * We don't care about the reason phrase.
437 	 */
438 	if (strncmp(conn->buf, "HTTP", 4) != 0)
439 		return (HTTP_PROTOCOL_ERROR);
440 	p = conn->buf + 4;
441 	if (*p == '/') {
442 		if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
443 			return (HTTP_PROTOCOL_ERROR);
444 		p += 4;
445 	}
446 	if (*p != ' ' ||
447 	    !isdigit((unsigned char)p[1]) ||
448 	    !isdigit((unsigned char)p[2]) ||
449 	    !isdigit((unsigned char)p[3]))
450 		return (HTTP_PROTOCOL_ERROR);
451 
452 	conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
453 	return (conn->err);
454 }
455 
456 /*
457  * Check a header; if the type matches the given string, return a pointer
458  * to the beginning of the value.
459  */
460 static const char *
461 http_match(const char *str, const char *hdr)
462 {
463 	while (*str && *hdr &&
464 	    tolower((unsigned char)*str++) == tolower((unsigned char)*hdr++))
465 		/* nothing */;
466 	if (*str || *hdr != ':')
467 		return (NULL);
468 	while (*hdr && isspace((unsigned char)*++hdr))
469 		/* nothing */;
470 	return (hdr);
471 }
472 
473 
474 /*
475  * Get the next header and return the appropriate symbolic code.  We
476  * need to read one line ahead for checking for a continuation line
477  * belonging to the current header (continuation lines start with
478  * white space).
479  *
480  * We get called with a fresh line already in the conn buffer, either
481  * from the previous http_next_header() invocation, or, the first
482  * time, from a fetch_getln() performed by our caller.
483  *
484  * This stops when we encounter an empty line (we dont read beyond the header
485  * area).
486  *
487  * Note that the "headerbuf" is just a place to return the result. Its
488  * contents are not used for the next call. This means that no cleanup
489  * is needed when ie doing another connection, just call the cleanup when
490  * fully done to deallocate memory.
491  */
492 
493 /* Limit the max number of continuation lines to some reasonable value */
494 #define HTTP_MAX_CONT_LINES 10
495 
496 /* Place into which to build a header from one or several lines */
497 typedef struct {
498 	char	*buf;		/* buffer */
499 	size_t	 bufsize;	/* buffer size */
500 	size_t	 buflen;	/* length of buffer contents */
501 } http_headerbuf_t;
502 
503 static void
504 init_http_headerbuf(http_headerbuf_t *buf)
505 {
506 	buf->buf = NULL;
507 	buf->bufsize = 0;
508 	buf->buflen = 0;
509 }
510 
511 static void
512 clean_http_headerbuf(http_headerbuf_t *buf)
513 {
514 	if (buf->buf)
515 		free(buf->buf);
516 	init_http_headerbuf(buf);
517 }
518 
519 /* Remove whitespace at the end of the buffer */
520 static void
521 http_conn_trimright(conn_t *conn)
522 {
523 	while (conn->buflen &&
524 	       isspace((unsigned char)conn->buf[conn->buflen - 1]))
525 		conn->buflen--;
526 	conn->buf[conn->buflen] = '\0';
527 }
528 
529 static hdr_t
530 http_next_header(conn_t *conn, http_headerbuf_t *hbuf, const char **p)
531 {
532 	unsigned int i, len;
533 
534 	/*
535 	 * Have to do the stripping here because of the first line. So
536 	 * it's done twice for the subsequent lines. No big deal
537 	 */
538 	http_conn_trimright(conn);
539 	if (conn->buflen == 0)
540 		return (hdr_end);
541 
542 	/* Copy the line to the headerbuf */
543 	if (hbuf->bufsize < conn->buflen + 1) {
544 		if ((hbuf->buf = realloc(hbuf->buf, conn->buflen + 1)) == NULL)
545 			return (hdr_syserror);
546 		hbuf->bufsize = conn->buflen + 1;
547 	}
548 	strcpy(hbuf->buf, conn->buf);
549 	hbuf->buflen = conn->buflen;
550 
551 	/*
552 	 * Fetch possible continuation lines. Stop at 1st non-continuation
553 	 * and leave it in the conn buffer
554 	 */
555 	for (i = 0; i < HTTP_MAX_CONT_LINES; i++) {
556 		if (fetch_getln(conn) == -1)
557 			return (hdr_syserror);
558 
559 		/*
560 		 * Note: we carry on the idea from the previous version
561 		 * that a pure whitespace line is equivalent to an empty
562 		 * one (so it's not continuation and will be handled when
563 		 * we are called next)
564 		 */
565 		http_conn_trimright(conn);
566 		if (conn->buf[0] != ' ' && conn->buf[0] != "\t"[0])
567 			break;
568 
569 		/* Got a continuation line. Concatenate to previous */
570 		len = hbuf->buflen + conn->buflen;
571 		if (hbuf->bufsize < len + 1) {
572 			len *= 2;
573 			if ((hbuf->buf = realloc(hbuf->buf, len + 1)) == NULL)
574 				return (hdr_syserror);
575 			hbuf->bufsize = len + 1;
576 		}
577 		strcpy(hbuf->buf + hbuf->buflen, conn->buf);
578 		hbuf->buflen += conn->buflen;
579 	}
580 
581 	/*
582 	 * We could check for malformed headers but we don't really care.
583 	 * A valid header starts with a token immediately followed by a
584 	 * colon; a token is any sequence of non-control, non-whitespace
585 	 * characters except "()<>@,;:\\\"{}".
586 	 */
587 	for (i = 0; hdr_names[i].num != hdr_unknown; i++)
588 		if ((*p = http_match(hdr_names[i].name, hbuf->buf)) != NULL)
589 			return (hdr_names[i].num);
590 
591 	return (hdr_unknown);
592 }
593 
594 /**************************
595  * [Proxy-]Authenticate header parsing
596  */
597 
598 /*
599  * Read doublequote-delimited string into output buffer obuf (allocated
600  * by caller, whose responsibility it is to ensure that it's big enough)
601  * cp points to the first char after the initial '"'
602  * Handles \ quoting
603  * Returns pointer to the first char after the terminating double quote, or
604  * NULL for error.
605  */
606 static const char *
607 http_parse_headerstring(const char *cp, char *obuf)
608 {
609 	for (;;) {
610 		switch (*cp) {
611 		case 0: /* Unterminated string */
612 			*obuf = 0;
613 			return (NULL);
614 		case '"': /* Ending quote */
615 			*obuf = 0;
616 			return (++cp);
617 		case '\\':
618 			if (*++cp == 0) {
619 				*obuf = 0;
620 				return (NULL);
621 			}
622 			/* FALLTHROUGH */
623 		default:
624 			*obuf++ = *cp++;
625 		}
626 	}
627 }
628 
629 /* Http auth challenge schemes */
630 typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
631 
632 /* Data holder for a Basic or Digest challenge. */
633 typedef struct {
634 	http_auth_schemes_t scheme;
635 	char	*realm;
636 	char	*qop;
637 	char	*nonce;
638 	char	*opaque;
639 	char	*algo;
640 	int	 stale;
641 	int	 nc; /* Nonce count */
642 } http_auth_challenge_t;
643 
644 static void
645 init_http_auth_challenge(http_auth_challenge_t *b)
646 {
647 	b->scheme = HTTPAS_UNKNOWN;
648 	b->realm = b->qop = b->nonce = b->opaque = b->algo = NULL;
649 	b->stale = b->nc = 0;
650 }
651 
652 static void
653 clean_http_auth_challenge(http_auth_challenge_t *b)
654 {
655 	if (b->realm)
656 		free(b->realm);
657 	if (b->qop)
658 		free(b->qop);
659 	if (b->nonce)
660 		free(b->nonce);
661 	if (b->opaque)
662 		free(b->opaque);
663 	if (b->algo)
664 		free(b->algo);
665 	init_http_auth_challenge(b);
666 }
667 
668 /* Data holder for an array of challenges offered in an http response. */
669 #define MAX_CHALLENGES 10
670 typedef struct {
671 	http_auth_challenge_t *challenges[MAX_CHALLENGES];
672 	int	count; /* Number of parsed challenges in the array */
673 	int	valid; /* We did parse an authenticate header */
674 } http_auth_challenges_t;
675 
676 static void
677 init_http_auth_challenges(http_auth_challenges_t *cs)
678 {
679 	int i;
680 	for (i = 0; i < MAX_CHALLENGES; i++)
681 		cs->challenges[i] = NULL;
682 	cs->count = cs->valid = 0;
683 }
684 
685 static void
686 clean_http_auth_challenges(http_auth_challenges_t *cs)
687 {
688 	int i;
689 	/* We rely on non-zero pointers being allocated, not on the count */
690 	for (i = 0; i < MAX_CHALLENGES; i++) {
691 		if (cs->challenges[i] != NULL) {
692 			clean_http_auth_challenge(cs->challenges[i]);
693 			free(cs->challenges[i]);
694 		}
695 	}
696 	init_http_auth_challenges(cs);
697 }
698 
699 /*
700  * Enumeration for lexical elements. Separators will be returned as their own
701  * ascii value
702  */
703 typedef enum {HTTPHL_WORD=256, HTTPHL_STRING=257, HTTPHL_END=258,
704 	      HTTPHL_ERROR = 259} http_header_lex_t;
705 
706 /*
707  * Determine what kind of token comes next and return possible value
708  * in buf, which is supposed to have been allocated big enough by
709  * caller. Advance input pointer and return element type.
710  */
711 static int
712 http_header_lex(const char **cpp, char *buf)
713 {
714 	size_t l;
715 	/* Eat initial whitespace */
716 	*cpp += strspn(*cpp, " \t");
717 	if (**cpp == 0)
718 		return (HTTPHL_END);
719 
720 	/* Separator ? */
721 	if (**cpp == ',' || **cpp == '=')
722 		return (*((*cpp)++));
723 
724 	/* String ? */
725 	if (**cpp == '"') {
726 		*cpp = http_parse_headerstring(++*cpp, buf);
727 		if (*cpp == NULL)
728 			return (HTTPHL_ERROR);
729 		return (HTTPHL_STRING);
730 	}
731 
732 	/* Read other token, until separator or whitespace */
733 	l = strcspn(*cpp, " \t,=");
734 	memcpy(buf, *cpp, l);
735 	buf[l] = 0;
736 	*cpp += l;
737 	return (HTTPHL_WORD);
738 }
739 
740 /*
741  * Read challenges from http xxx-authenticate header and accumulate them
742  * in the challenges list structure.
743  *
744  * Headers with multiple challenges are specified by rfc2617, but
745  * servers (ie: squid) often send them in separate headers instead,
746  * which in turn is forbidden by the http spec (multiple headers with
747  * the same name are only allowed for pure comma-separated lists, see
748  * rfc2616 sec 4.2).
749  *
750  * We support both approaches anyway
751  */
752 static int
753 http_parse_authenticate(const char *cp, http_auth_challenges_t *cs)
754 {
755 	int ret = -1;
756 	http_header_lex_t lex;
757 	char *key = malloc(strlen(cp) + 1);
758 	char *value = malloc(strlen(cp) + 1);
759 	char *buf = malloc(strlen(cp) + 1);
760 
761 	if (key == NULL || value == NULL || buf == NULL) {
762 		fetch_syserr();
763 		goto out;
764 	}
765 
766 	/* In any case we've seen the header and we set the valid bit */
767 	cs->valid = 1;
768 
769 	/* Need word first */
770 	lex = http_header_lex(&cp, key);
771 	if (lex != HTTPHL_WORD)
772 		goto out;
773 
774 	/* Loop on challenges */
775 	for (; cs->count < MAX_CHALLENGES; cs->count++) {
776 		cs->challenges[cs->count] =
777 			malloc(sizeof(http_auth_challenge_t));
778 		if (cs->challenges[cs->count] == NULL) {
779 			fetch_syserr();
780 			goto out;
781 		}
782 		init_http_auth_challenge(cs->challenges[cs->count]);
783 		if (strcasecmp(key, "basic") == 0) {
784 			cs->challenges[cs->count]->scheme = HTTPAS_BASIC;
785 		} else if (strcasecmp(key, "digest") == 0) {
786 			cs->challenges[cs->count]->scheme = HTTPAS_DIGEST;
787 		} else {
788 			cs->challenges[cs->count]->scheme = HTTPAS_UNKNOWN;
789 			/*
790 			 * Continue parsing as basic or digest may
791 			 * follow, and the syntax is the same for
792 			 * all. We'll just ignore this one when
793 			 * looking at the list
794 			 */
795 		}
796 
797 		/* Loop on attributes */
798 		for (;;) {
799 			/* Key */
800 			lex = http_header_lex(&cp, key);
801 			if (lex != HTTPHL_WORD)
802 				goto out;
803 
804 			/* Equal sign */
805 			lex = http_header_lex(&cp, buf);
806 			if (lex != '=')
807 				goto out;
808 
809 			/* Value */
810 			lex = http_header_lex(&cp, value);
811 			if (lex != HTTPHL_WORD && lex != HTTPHL_STRING)
812 				goto out;
813 
814 			if (strcasecmp(key, "realm") == 0) {
815 				cs->challenges[cs->count]->realm =
816 				    strdup(value);
817 			} else if (strcasecmp(key, "qop") == 0) {
818 				cs->challenges[cs->count]->qop =
819 				    strdup(value);
820 			} else if (strcasecmp(key, "nonce") == 0) {
821 				cs->challenges[cs->count]->nonce =
822 				    strdup(value);
823 			} else if (strcasecmp(key, "opaque") == 0) {
824 				cs->challenges[cs->count]->opaque =
825 				    strdup(value);
826 			} else if (strcasecmp(key, "algorithm") == 0) {
827 				cs->challenges[cs->count]->algo =
828 				    strdup(value);
829 			} else if (strcasecmp(key, "stale") == 0) {
830 				cs->challenges[cs->count]->stale =
831 				    strcasecmp(value, "no");
832 			} else {
833 				/* ignore unknown attributes */
834 			}
835 
836 			/* Comma or Next challenge or End */
837 			lex = http_header_lex(&cp, key);
838 			/*
839 			 * If we get a word here, this is the beginning of the
840 			 * next challenge. Break the attributes loop
841 			 */
842 			if (lex == HTTPHL_WORD)
843 				break;
844 
845 			if (lex == HTTPHL_END) {
846 				/* End while looking for ',' is normal exit */
847 				cs->count++;
848 				ret = 0;
849 				goto out;
850 			}
851 			/* Anything else is an error */
852 			if (lex != ',')
853 				goto out;
854 
855 		} /* End attributes loop */
856 	} /* End challenge loop */
857 
858 	/*
859 	 * Challenges max count exceeded. This really can't happen
860 	 * with normal data, something's fishy -> error
861 	 */
862 
863 out:
864 	if (key)
865 		free(key);
866 	if (value)
867 		free(value);
868 	if (buf)
869 		free(buf);
870 	return (ret);
871 }
872 
873 
874 /*
875  * Parse a last-modified header
876  */
877 static int
878 http_parse_mtime(const char *p, time_t *mtime)
879 {
880 	char locale[64], *r;
881 	struct tm tm;
882 
883 	strlcpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
884 	setlocale(LC_TIME, "C");
885 	r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
886 	/*
887 	 * Some proxies use UTC in response, but it should still be
888 	 * parsed. RFC2616 states GMT and UTC are exactly equal for HTTP.
889 	 */
890 	if (r == NULL)
891 		r = strptime(p, "%a, %d %b %Y %H:%M:%S UTC", &tm);
892 	/* XXX should add support for date-2 and date-3 */
893 	setlocale(LC_TIME, locale);
894 	if (r == NULL)
895 		return (-1);
896 	DEBUGF("last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
897 	    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
898 	    tm.tm_hour, tm.tm_min, tm.tm_sec);
899 	*mtime = timegm(&tm);
900 	return (0);
901 }
902 
903 /*
904  * Parse a content-length header
905  */
906 static int
907 http_parse_length(const char *p, off_t *length)
908 {
909 	off_t len;
910 
911 	for (len = 0; *p && isdigit((unsigned char)*p); ++p)
912 		len = len * 10 + (*p - '0');
913 	if (*p)
914 		return (-1);
915 	DEBUGF("content length: [%lld]\n", (long long)len);
916 	*length = len;
917 	return (0);
918 }
919 
920 /*
921  * Parse a content-range header
922  */
923 static int
924 http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
925 {
926 	off_t first, last, len;
927 
928 	if (strncasecmp(p, "bytes ", 6) != 0)
929 		return (-1);
930 	p += 6;
931 	if (*p == '*') {
932 		first = last = -1;
933 		++p;
934 	} else {
935 		for (first = 0; *p && isdigit((unsigned char)*p); ++p)
936 			first = first * 10 + *p - '0';
937 		if (*p != '-')
938 			return (-1);
939 		for (last = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
940 			last = last * 10 + *p - '0';
941 	}
942 	if (first > last || *p != '/')
943 		return (-1);
944 	for (len = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
945 		len = len * 10 + *p - '0';
946 	if (*p || len < last - first + 1)
947 		return (-1);
948 	if (first == -1) {
949 		DEBUGF("content range: [*/%lld]\n", (long long)len);
950 		*length = 0;
951 	} else {
952 		DEBUGF("content range: [%lld-%lld/%lld]\n",
953 		    (long long)first, (long long)last, (long long)len);
954 		*length = last - first + 1;
955 	}
956 	*offset = first;
957 	*size = len;
958 	return (0);
959 }
960 
961 
962 /*****************************************************************************
963  * Helper functions for authorization
964  */
965 
966 /*
967  * Base64 encoding
968  */
969 static char *
970 http_base64(const char *src)
971 {
972 	static const char base64[] =
973 	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
974 	    "abcdefghijklmnopqrstuvwxyz"
975 	    "0123456789+/";
976 	char *str, *dst;
977 	size_t l;
978 	int t, r;
979 
980 	l = strlen(src);
981 	if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
982 		return (NULL);
983 	dst = str;
984 	r = 0;
985 
986 	while (l >= 3) {
987 		t = (src[0] << 16) | (src[1] << 8) | src[2];
988 		dst[0] = base64[(t >> 18) & 0x3f];
989 		dst[1] = base64[(t >> 12) & 0x3f];
990 		dst[2] = base64[(t >> 6) & 0x3f];
991 		dst[3] = base64[(t >> 0) & 0x3f];
992 		src += 3; l -= 3;
993 		dst += 4; r += 4;
994 	}
995 
996 	switch (l) {
997 	case 2:
998 		t = (src[0] << 16) | (src[1] << 8);
999 		dst[0] = base64[(t >> 18) & 0x3f];
1000 		dst[1] = base64[(t >> 12) & 0x3f];
1001 		dst[2] = base64[(t >> 6) & 0x3f];
1002 		dst[3] = '=';
1003 		dst += 4;
1004 		r += 4;
1005 		break;
1006 	case 1:
1007 		t = src[0] << 16;
1008 		dst[0] = base64[(t >> 18) & 0x3f];
1009 		dst[1] = base64[(t >> 12) & 0x3f];
1010 		dst[2] = dst[3] = '=';
1011 		dst += 4;
1012 		r += 4;
1013 		break;
1014 	case 0:
1015 		break;
1016 	}
1017 
1018 	*dst = 0;
1019 	return (str);
1020 }
1021 
1022 
1023 /*
1024  * Extract authorization parameters from environment value.
1025  * The value is like scheme:realm:user:pass
1026  */
1027 typedef struct {
1028 	char	*scheme;
1029 	char	*realm;
1030 	char	*user;
1031 	char	*password;
1032 } http_auth_params_t;
1033 
1034 static void
1035 init_http_auth_params(http_auth_params_t *s)
1036 {
1037 	s->scheme = s->realm = s->user = s->password = NULL;
1038 }
1039 
1040 static void
1041 clean_http_auth_params(http_auth_params_t *s)
1042 {
1043 	if (s->scheme)
1044 		free(s->scheme);
1045 	if (s->realm)
1046 		free(s->realm);
1047 	if (s->user)
1048 		free(s->user);
1049 	if (s->password)
1050 		free(s->password);
1051 	init_http_auth_params(s);
1052 }
1053 
1054 static int
1055 http_authfromenv(const char *p, http_auth_params_t *parms)
1056 {
1057 	int ret = -1;
1058 	char *v, *ve;
1059 	char *str = strdup(p);
1060 
1061 	if (str == NULL) {
1062 		fetch_syserr();
1063 		return (-1);
1064 	}
1065 	v = str;
1066 
1067 	if ((ve = strchr(v, ':')) == NULL)
1068 		goto out;
1069 
1070 	*ve = 0;
1071 	if ((parms->scheme = strdup(v)) == NULL) {
1072 		fetch_syserr();
1073 		goto out;
1074 	}
1075 	v = ve + 1;
1076 
1077 	if ((ve = strchr(v, ':')) == NULL)
1078 		goto out;
1079 
1080 	*ve = 0;
1081 	if ((parms->realm = strdup(v)) == NULL) {
1082 		fetch_syserr();
1083 		goto out;
1084 	}
1085 	v = ve + 1;
1086 
1087 	if ((ve = strchr(v, ':')) == NULL)
1088 		goto out;
1089 
1090 	*ve = 0;
1091 	if ((parms->user = strdup(v)) == NULL) {
1092 		fetch_syserr();
1093 		goto out;
1094 	}
1095 	v = ve + 1;
1096 
1097 
1098 	if ((parms->password = strdup(v)) == NULL) {
1099 		fetch_syserr();
1100 		goto out;
1101 	}
1102 	ret = 0;
1103 out:
1104 	if (ret == -1)
1105 		clean_http_auth_params(parms);
1106 	if (str)
1107 		free(str);
1108 	return (ret);
1109 }
1110 
1111 
1112 /*
1113  * Digest response: the code to compute the digest is taken from the
1114  * sample implementation in RFC2616
1115  */
1116 #define IN const
1117 #define OUT
1118 
1119 #define HASHLEN 16
1120 typedef char HASH[HASHLEN];
1121 #define HASHHEXLEN 32
1122 typedef char HASHHEX[HASHHEXLEN+1];
1123 
1124 static const char *hexchars = "0123456789abcdef";
1125 static void
1126 CvtHex(IN HASH Bin, OUT HASHHEX Hex)
1127 {
1128 	unsigned short i;
1129 	unsigned char j;
1130 
1131 	for (i = 0; i < HASHLEN; i++) {
1132 		j = (Bin[i] >> 4) & 0xf;
1133 		Hex[i*2] = hexchars[j];
1134 		j = Bin[i] & 0xf;
1135 		Hex[i*2+1] = hexchars[j];
1136 	}
1137 	Hex[HASHHEXLEN] = '\0';
1138 };
1139 
1140 /* calculate H(A1) as per spec */
1141 static void
1142 DigestCalcHA1(
1143 	IN char * pszAlg,
1144 	IN char * pszUserName,
1145 	IN char * pszRealm,
1146 	IN char * pszPassword,
1147 	IN char * pszNonce,
1148 	IN char * pszCNonce,
1149 	OUT HASHHEX SessionKey
1150 	)
1151 {
1152 	MD5_CTX Md5Ctx;
1153 	HASH HA1;
1154 
1155 	MD5Init(&Md5Ctx);
1156 	MD5Update(&Md5Ctx, pszUserName, strlen(pszUserName));
1157 	MD5Update(&Md5Ctx, ":", 1);
1158 	MD5Update(&Md5Ctx, pszRealm, strlen(pszRealm));
1159 	MD5Update(&Md5Ctx, ":", 1);
1160 	MD5Update(&Md5Ctx, pszPassword, strlen(pszPassword));
1161 	MD5Final(HA1, &Md5Ctx);
1162 	if (strcasecmp(pszAlg, "md5-sess") == 0) {
1163 
1164 		MD5Init(&Md5Ctx);
1165 		MD5Update(&Md5Ctx, HA1, HASHLEN);
1166 		MD5Update(&Md5Ctx, ":", 1);
1167 		MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1168 		MD5Update(&Md5Ctx, ":", 1);
1169 		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1170 		MD5Final(HA1, &Md5Ctx);
1171 	}
1172 	CvtHex(HA1, SessionKey);
1173 }
1174 
1175 /* calculate request-digest/response-digest as per HTTP Digest spec */
1176 static void
1177 DigestCalcResponse(
1178 	IN HASHHEX HA1,           /* H(A1) */
1179 	IN char * pszNonce,       /* nonce from server */
1180 	IN char * pszNonceCount,  /* 8 hex digits */
1181 	IN char * pszCNonce,      /* client nonce */
1182 	IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
1183 	IN char * pszMethod,      /* method from the request */
1184 	IN char * pszDigestUri,   /* requested URL */
1185 	IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
1186 	OUT HASHHEX Response      /* request-digest or response-digest */
1187 	)
1188 {
1189 #if 0
1190 	DEBUGF("Calc: HA1[%s] Nonce[%s] qop[%s] method[%s] URI[%s]\n",
1191 	    HA1, pszNonce, pszQop, pszMethod, pszDigestUri);
1192 #endif
1193 	MD5_CTX Md5Ctx;
1194 	HASH HA2;
1195 	HASH RespHash;
1196 	HASHHEX HA2Hex;
1197 
1198 	// calculate H(A2)
1199 	MD5Init(&Md5Ctx);
1200 	MD5Update(&Md5Ctx, pszMethod, strlen(pszMethod));
1201 	MD5Update(&Md5Ctx, ":", 1);
1202 	MD5Update(&Md5Ctx, pszDigestUri, strlen(pszDigestUri));
1203 	if (strcasecmp(pszQop, "auth-int") == 0) {
1204 		MD5Update(&Md5Ctx, ":", 1);
1205 		MD5Update(&Md5Ctx, HEntity, HASHHEXLEN);
1206 	}
1207 	MD5Final(HA2, &Md5Ctx);
1208 	CvtHex(HA2, HA2Hex);
1209 
1210 	// calculate response
1211 	MD5Init(&Md5Ctx);
1212 	MD5Update(&Md5Ctx, HA1, HASHHEXLEN);
1213 	MD5Update(&Md5Ctx, ":", 1);
1214 	MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1215 	MD5Update(&Md5Ctx, ":", 1);
1216 	if (*pszQop) {
1217 		MD5Update(&Md5Ctx, pszNonceCount, strlen(pszNonceCount));
1218 		MD5Update(&Md5Ctx, ":", 1);
1219 		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1220 		MD5Update(&Md5Ctx, ":", 1);
1221 		MD5Update(&Md5Ctx, pszQop, strlen(pszQop));
1222 		MD5Update(&Md5Ctx, ":", 1);
1223 	}
1224 	MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
1225 	MD5Final(RespHash, &Md5Ctx);
1226 	CvtHex(RespHash, Response);
1227 }
1228 
1229 /*
1230  * Generate/Send a Digest authorization header
1231  * This looks like: [Proxy-]Authorization: credentials
1232  *
1233  *  credentials      = "Digest" digest-response
1234  *  digest-response  = 1#( username | realm | nonce | digest-uri
1235  *                      | response | [ algorithm ] | [cnonce] |
1236  *                      [opaque] | [message-qop] |
1237  *                          [nonce-count]  | [auth-param] )
1238  *  username         = "username" "=" username-value
1239  *  username-value   = quoted-string
1240  *  digest-uri       = "uri" "=" digest-uri-value
1241  *  digest-uri-value = request-uri   ; As specified by HTTP/1.1
1242  *  message-qop      = "qop" "=" qop-value
1243  *  cnonce           = "cnonce" "=" cnonce-value
1244  *  cnonce-value     = nonce-value
1245  *  nonce-count      = "nc" "=" nc-value
1246  *  nc-value         = 8LHEX
1247  *  response         = "response" "=" request-digest
1248  *  request-digest = <"> 32LHEX <">
1249  */
1250 static int
1251 http_digest_auth(conn_t *conn, const char *hdr, http_auth_challenge_t *c,
1252 		 http_auth_params_t *parms, struct url *url)
1253 {
1254 	int r;
1255 	char noncecount[10];
1256 	char cnonce[40];
1257 	char *options = NULL;
1258 
1259 	if (!c->realm || !c->nonce) {
1260 		DEBUGF("realm/nonce not set in challenge\n");
1261 		return(-1);
1262 	}
1263 	if (!c->algo)
1264 		c->algo = strdup("");
1265 
1266 	if (asprintf(&options, "%s%s%s%s",
1267 	    *c->algo? ",algorithm=" : "", c->algo,
1268 	    c->opaque? ",opaque=" : "", c->opaque?c->opaque:"") < 0)
1269 		return (-1);
1270 
1271 	if (!c->qop) {
1272 		c->qop = strdup("");
1273 		*noncecount = 0;
1274 		*cnonce = 0;
1275 	} else {
1276 		c->nc++;
1277 		sprintf(noncecount, "%08x", c->nc);
1278 		/* We don't try very hard with the cnonce ... */
1279 		sprintf(cnonce, "%x%lx", getpid(), (unsigned long)time(0));
1280 	}
1281 
1282 	HASHHEX HA1;
1283 	DigestCalcHA1(c->algo, parms->user, c->realm,
1284 		      parms->password, c->nonce, cnonce, HA1);
1285 	DEBUGF("HA1: [%s]\n", HA1);
1286 	HASHHEX digest;
1287 	DigestCalcResponse(HA1, c->nonce, noncecount, cnonce, c->qop,
1288 			   "GET", url->doc, "", digest);
1289 
1290 	if (c->qop[0]) {
1291 		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1292 			     "nonce=\"%s\",uri=\"%s\",response=\"%s\","
1293 			     "qop=\"auth\", cnonce=\"%s\", nc=%s%s",
1294 			     hdr, parms->user, c->realm,
1295 			     c->nonce, url->doc, digest,
1296 			     cnonce, noncecount, options);
1297 	} else {
1298 		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1299 			     "nonce=\"%s\",uri=\"%s\",response=\"%s\"%s",
1300 			     hdr, parms->user, c->realm,
1301 			     c->nonce, url->doc, digest, options);
1302 	}
1303 	if (options)
1304 		free(options);
1305 	return (r);
1306 }
1307 
1308 /*
1309  * Encode username and password
1310  */
1311 static int
1312 http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
1313 {
1314 	char *upw, *auth;
1315 	int r;
1316 
1317 	DEBUGF("basic: usr: [%s]\n", usr);
1318 	DEBUGF("basic: pwd: [%s]\n", pwd);
1319 	if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
1320 		return (-1);
1321 	auth = http_base64(upw);
1322 	free(upw);
1323 	if (auth == NULL)
1324 		return (-1);
1325 	r = http_cmd(conn, "%s: Basic %s", hdr, auth);
1326 	free(auth);
1327 	return (r);
1328 }
1329 
1330 /*
1331  * Chose the challenge to answer and call the appropriate routine to
1332  * produce the header.
1333  */
1334 static int
1335 http_authorize(conn_t *conn, const char *hdr, http_auth_challenges_t *cs,
1336 	       http_auth_params_t *parms, struct url *url)
1337 {
1338 	http_auth_challenge_t *digest = NULL;
1339 	int i;
1340 
1341 	/* If user or pass are null we're not happy */
1342 	if (!parms->user || !parms->password) {
1343 		DEBUGF("NULL usr or pass\n");
1344 		return (-1);
1345 	}
1346 
1347 	/* Look for a Digest */
1348 	for (i = 0; i < cs->count; i++) {
1349 		if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1350 			digest = cs->challenges[i];
1351 	}
1352 
1353 	/* Error if "Digest" was specified and there is no Digest challenge */
1354 	if (!digest &&
1355 	    (parms->scheme && strcasecmp(parms->scheme, "digest") == 0)) {
1356 		DEBUGF("Digest auth in env, not supported by peer\n");
1357 		return (-1);
1358 	}
1359 	/*
1360 	 * If "basic" was specified in the environment, or there is no Digest
1361 	 * challenge, do the basic thing. Don't need a challenge for this,
1362 	 * so no need to check basic!=NULL
1363 	 */
1364 	if (!digest ||
1365 	    (parms->scheme && strcasecmp(parms->scheme, "basic") == 0))
1366 		return (http_basic_auth(conn,hdr,parms->user,parms->password));
1367 
1368 	/* Else, prefer digest. We just checked that it's not NULL */
1369 	return (http_digest_auth(conn, hdr, digest, parms, url));
1370 }
1371 
1372 /*****************************************************************************
1373  * Helper functions for connecting to a server or proxy
1374  */
1375 
1376 /*
1377  * Connect to the correct HTTP server or proxy.
1378  */
1379 static conn_t *
1380 http_connect(struct url *URL, struct url *purl, const char *flags)
1381 {
1382 	struct url *curl;
1383 	conn_t *conn;
1384 	hdr_t h;
1385 	http_headerbuf_t headerbuf;
1386 	const char *p;
1387 	int verbose;
1388 	int af, val;
1389 	int serrno;
1390 
1391 #ifdef INET6
1392 	af = AF_UNSPEC;
1393 #else
1394 	af = AF_INET;
1395 #endif
1396 
1397 	verbose = CHECK_FLAG('v');
1398 	if (CHECK_FLAG('4'))
1399 		af = AF_INET;
1400 #ifdef INET6
1401 	else if (CHECK_FLAG('6'))
1402 		af = AF_INET6;
1403 #endif
1404 
1405 	curl = (purl != NULL) ? purl : URL;
1406 
1407 	if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1408 		/* fetch_connect() has already set an error code */
1409 		return (NULL);
1410 	init_http_headerbuf(&headerbuf);
1411 	if (strcmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1412 		http_cmd(conn, "CONNECT %s:%d HTTP/1.1",
1413 		    URL->host, URL->port);
1414 		http_cmd(conn, "Host: %s:%d",
1415 		    URL->host, URL->port);
1416 		http_cmd(conn, "");
1417 		if (http_get_reply(conn) != HTTP_OK) {
1418 			http_seterr(conn->err);
1419 			goto ouch;
1420 		}
1421 		/* Read and discard the rest of the proxy response */
1422 		if (fetch_getln(conn) < 0) {
1423 			fetch_syserr();
1424 			goto ouch;
1425 		}
1426 		do {
1427 			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1428 			case hdr_syserror:
1429 				fetch_syserr();
1430 				goto ouch;
1431 			case hdr_error:
1432 				http_seterr(HTTP_PROTOCOL_ERROR);
1433 				goto ouch;
1434 			default:
1435 				/* ignore */ ;
1436 			}
1437 		} while (h > hdr_end);
1438 	}
1439 	if (strcmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1440 	    fetch_ssl(conn, URL, verbose) == -1) {
1441 		/* grrr */
1442 		errno = EAUTH;
1443 		fetch_syserr();
1444 		goto ouch;
1445 	}
1446 
1447 	val = 1;
1448 	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1449 
1450 	clean_http_headerbuf(&headerbuf);
1451 	return (conn);
1452 ouch:
1453 	serrno = errno;
1454 	clean_http_headerbuf(&headerbuf);
1455 	fetch_close(conn);
1456 	errno = serrno;
1457 	return (NULL);
1458 }
1459 
1460 static struct url *
1461 http_get_proxy(struct url * url, const char *flags)
1462 {
1463 	struct url *purl;
1464 	char *p;
1465 
1466 	if (flags != NULL && strchr(flags, 'd') != NULL)
1467 		return (NULL);
1468 	if (fetch_no_proxy_match(url->host))
1469 		return (NULL);
1470 	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1471 	    *p && (purl = fetchParseURL(p))) {
1472 		if (!*purl->scheme)
1473 			strcpy(purl->scheme, SCHEME_HTTP);
1474 		if (!purl->port)
1475 			purl->port = fetch_default_proxy_port(purl->scheme);
1476 		if (strcmp(purl->scheme, SCHEME_HTTP) == 0)
1477 			return (purl);
1478 		fetchFreeURL(purl);
1479 	}
1480 	return (NULL);
1481 }
1482 
1483 static void
1484 http_print_html(FILE *out, FILE *in)
1485 {
1486 	size_t len;
1487 	char *line, *p, *q;
1488 	int comment, tag;
1489 
1490 	comment = tag = 0;
1491 	while ((line = fgetln(in, &len)) != NULL) {
1492 		while (len && isspace((unsigned char)line[len - 1]))
1493 			--len;
1494 		for (p = q = line; q < line + len; ++q) {
1495 			if (comment && *q == '-') {
1496 				if (q + 2 < line + len &&
1497 				    strcmp(q, "-->") == 0) {
1498 					tag = comment = 0;
1499 					q += 2;
1500 				}
1501 			} else if (tag && !comment && *q == '>') {
1502 				p = q + 1;
1503 				tag = 0;
1504 			} else if (!tag && *q == '<') {
1505 				if (q > p)
1506 					fwrite(p, q - p, 1, out);
1507 				tag = 1;
1508 				if (q + 3 < line + len &&
1509 				    strcmp(q, "<!--") == 0) {
1510 					comment = 1;
1511 					q += 3;
1512 				}
1513 			}
1514 		}
1515 		if (!tag && q > p)
1516 			fwrite(p, q - p, 1, out);
1517 		fputc('\n', out);
1518 	}
1519 }
1520 
1521 
1522 /*****************************************************************************
1523  * Core
1524  */
1525 
1526 FILE *
1527 http_request(struct url *URL, const char *op, struct url_stat *us,
1528 	struct url *purl, const char *flags)
1529 {
1530 
1531 	return (http_request_body(URL, op, us, purl, flags, NULL, NULL));
1532 }
1533 
1534 /*
1535  * Send a request and process the reply
1536  *
1537  * XXX This function is way too long, the do..while loop should be split
1538  * XXX off into a separate function.
1539  */
1540 FILE *
1541 http_request_body(struct url *URL, const char *op, struct url_stat *us,
1542 	struct url *purl, const char *flags, const char *content_type,
1543 	const char *body)
1544 {
1545 	char timebuf[80];
1546 	char hbuf[MAXHOSTNAMELEN + 7], *host;
1547 	conn_t *conn;
1548 	struct url *url, *new;
1549 	int chunked, direct, ims, noredirect, verbose;
1550 	int e, i, n, val;
1551 	off_t offset, clength, length, size;
1552 	time_t mtime;
1553 	const char *p;
1554 	FILE *f;
1555 	hdr_t h;
1556 	struct tm *timestruct;
1557 	http_headerbuf_t headerbuf;
1558 	http_auth_challenges_t server_challenges;
1559 	http_auth_challenges_t proxy_challenges;
1560 	size_t body_len;
1561 
1562 	/* The following calls don't allocate anything */
1563 	init_http_headerbuf(&headerbuf);
1564 	init_http_auth_challenges(&server_challenges);
1565 	init_http_auth_challenges(&proxy_challenges);
1566 
1567 	direct = CHECK_FLAG('d');
1568 	noredirect = CHECK_FLAG('A');
1569 	verbose = CHECK_FLAG('v');
1570 	ims = CHECK_FLAG('i');
1571 
1572 	if (direct && purl) {
1573 		fetchFreeURL(purl);
1574 		purl = NULL;
1575 	}
1576 
1577 	/* try the provided URL first */
1578 	url = URL;
1579 
1580 	n = MAX_REDIRECT;
1581 	i = 0;
1582 
1583 	e = HTTP_PROTOCOL_ERROR;
1584 	do {
1585 		new = NULL;
1586 		chunked = 0;
1587 		offset = 0;
1588 		clength = -1;
1589 		length = -1;
1590 		size = -1;
1591 		mtime = 0;
1592 
1593 		/* check port */
1594 		if (!url->port)
1595 			url->port = fetch_default_port(url->scheme);
1596 
1597 		/* were we redirected to an FTP URL? */
1598 		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1599 			if (strcmp(op, "GET") == 0)
1600 				return (ftp_request(url, "RETR", us, purl, flags));
1601 			else if (strcmp(op, "HEAD") == 0)
1602 				return (ftp_request(url, "STAT", us, purl, flags));
1603 		}
1604 
1605 		/* connect to server or proxy */
1606 		if ((conn = http_connect(url, purl, flags)) == NULL)
1607 			goto ouch;
1608 
1609 		/* append port number only if necessary */
1610 		host = url->host;
1611 		if (url->port != fetch_default_port(url->scheme)) {
1612 			snprintf(hbuf, sizeof(hbuf), "%s:%d", host, url->port);
1613 			host = hbuf;
1614 		}
1615 
1616 		/* send request */
1617 		if (verbose)
1618 			fetch_info("requesting %s://%s%s",
1619 			    url->scheme, host, url->doc);
1620 		if (purl && strcmp(url->scheme, SCHEME_HTTPS) != 0) {
1621 			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1622 			    op, url->scheme, host, url->doc);
1623 		} else {
1624 			http_cmd(conn, "%s %s HTTP/1.1",
1625 			    op, url->doc);
1626 		}
1627 
1628 		if (ims && url->ims_time) {
1629 			timestruct = gmtime((time_t *)&url->ims_time);
1630 			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1631 			    timestruct);
1632 			if (verbose)
1633 				fetch_info("If-Modified-Since: %s", timebuf);
1634 			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1635 		}
1636 		/* virtual host */
1637 		http_cmd(conn, "Host: %s", host);
1638 
1639 		/*
1640 		 * Proxy authorization: we only send auth after we received
1641 		 * a 407 error. We do not first try basic anyway (changed
1642 		 * when support was added for digest-auth)
1643 		 */
1644 		if (purl && proxy_challenges.valid) {
1645 			http_auth_params_t aparams;
1646 			init_http_auth_params(&aparams);
1647 			if (*purl->user || *purl->pwd) {
1648 				aparams.user = strdup(purl->user);
1649 				aparams.password = strdup(purl->pwd);
1650 			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1651 				   *p != '\0') {
1652 				if (http_authfromenv(p, &aparams) < 0) {
1653 					http_seterr(HTTP_NEED_PROXY_AUTH);
1654 					goto ouch;
1655 				}
1656 			} else if (fetch_netrc_auth(purl) == 0) {
1657 				aparams.user = strdup(purl->user);
1658 				aparams.password = strdup(purl->pwd);
1659 			}
1660 			http_authorize(conn, "Proxy-Authorization",
1661 				       &proxy_challenges, &aparams, url);
1662 			clean_http_auth_params(&aparams);
1663 		}
1664 
1665 		/*
1666 		 * Server authorization: we never send "a priori"
1667 		 * Basic auth, which used to be done if user/pass were
1668 		 * set in the url. This would be weird because we'd send the
1669 		 * password in the clear even if Digest is finally to be
1670 		 * used (it would have made more sense for the
1671 		 * pre-digest version to do this when Basic was specified
1672 		 * in the environment)
1673 		 */
1674 		if (server_challenges.valid) {
1675 			http_auth_params_t aparams;
1676 			init_http_auth_params(&aparams);
1677 			if (*url->user || *url->pwd) {
1678 				aparams.user = strdup(url->user);
1679 				aparams.password = strdup(url->pwd);
1680 			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1681 				   *p != '\0') {
1682 				if (http_authfromenv(p, &aparams) < 0) {
1683 					http_seterr(HTTP_NEED_AUTH);
1684 					goto ouch;
1685 				}
1686 			} else if (fetch_netrc_auth(url) == 0) {
1687 				aparams.user = strdup(url->user);
1688 				aparams.password = strdup(url->pwd);
1689 			} else if (fetchAuthMethod &&
1690 				   fetchAuthMethod(url) == 0) {
1691 				aparams.user = strdup(url->user);
1692 				aparams.password = strdup(url->pwd);
1693 			} else {
1694 				http_seterr(HTTP_NEED_AUTH);
1695 				goto ouch;
1696 			}
1697 			http_authorize(conn, "Authorization",
1698 				       &server_challenges, &aparams, url);
1699 			clean_http_auth_params(&aparams);
1700 		}
1701 
1702 		/* other headers */
1703 		if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1704 			if (*p != '\0')
1705 				http_cmd(conn, "Accept: %s", p);
1706 		} else {
1707 			http_cmd(conn, "Accept: */*");
1708 		}
1709 		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1710 			if (strcasecmp(p, "auto") == 0)
1711 				http_cmd(conn, "Referer: %s://%s%s",
1712 				    url->scheme, host, url->doc);
1713 			else
1714 				http_cmd(conn, "Referer: %s", p);
1715 		}
1716 		if ((p = getenv("HTTP_USER_AGENT")) != NULL) {
1717 			/* no User-Agent if defined but empty */
1718 			if  (*p != '\0')
1719 				http_cmd(conn, "User-Agent: %s", p);
1720 		} else {
1721 			/* default User-Agent */
1722 			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER,
1723 			    getprogname());
1724 		}
1725 		if (url->offset > 0)
1726 			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1727 		http_cmd(conn, "Connection: close");
1728 
1729 		if (body) {
1730 			body_len = strlen(body);
1731 			http_cmd(conn, "Content-Length: %zu", body_len);
1732 			if (content_type != NULL)
1733 				http_cmd(conn, "Content-Type: %s", content_type);
1734 		}
1735 
1736 		http_cmd(conn, "");
1737 
1738 		if (body)
1739 			fetch_write(conn, body, body_len);
1740 
1741 		/*
1742 		 * Force the queued request to be dispatched.  Normally, one
1743 		 * would do this with shutdown(2) but squid proxies can be
1744 		 * configured to disallow such half-closed connections.  To
1745 		 * be compatible with such configurations, fiddle with socket
1746 		 * options to force the pending data to be written.
1747 		 */
1748 		val = 0;
1749 		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1750 			   sizeof(val));
1751 		val = 1;
1752 		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1753 			   sizeof(val));
1754 
1755 		/* get reply */
1756 		switch (http_get_reply(conn)) {
1757 		case HTTP_OK:
1758 		case HTTP_PARTIAL:
1759 		case HTTP_NOT_MODIFIED:
1760 			/* fine */
1761 			break;
1762 		case HTTP_MOVED_PERM:
1763 		case HTTP_MOVED_TEMP:
1764 		case HTTP_TEMP_REDIRECT:
1765 		case HTTP_PERM_REDIRECT:
1766 		case HTTP_SEE_OTHER:
1767 		case HTTP_USE_PROXY:
1768 			/*
1769 			 * Not so fine, but we still have to read the
1770 			 * headers to get the new location.
1771 			 */
1772 			break;
1773 		case HTTP_NEED_AUTH:
1774 			if (server_challenges.valid) {
1775 				/*
1776 				 * We already sent out authorization code,
1777 				 * so there's nothing more we can do.
1778 				 */
1779 				http_seterr(conn->err);
1780 				goto ouch;
1781 			}
1782 			/* try again, but send the password this time */
1783 			if (verbose)
1784 				fetch_info("server requires authorization");
1785 			break;
1786 		case HTTP_NEED_PROXY_AUTH:
1787 			if (proxy_challenges.valid) {
1788 				/*
1789 				 * We already sent our proxy
1790 				 * authorization code, so there's
1791 				 * nothing more we can do. */
1792 				http_seterr(conn->err);
1793 				goto ouch;
1794 			}
1795 			/* try again, but send the password this time */
1796 			if (verbose)
1797 				fetch_info("proxy requires authorization");
1798 			break;
1799 		case HTTP_BAD_RANGE:
1800 			/*
1801 			 * This can happen if we ask for 0 bytes because
1802 			 * we already have the whole file.  Consider this
1803 			 * a success for now, and check sizes later.
1804 			 */
1805 			break;
1806 		case HTTP_PROTOCOL_ERROR:
1807 			/* fall through */
1808 		case -1:
1809 			fetch_syserr();
1810 			goto ouch;
1811 		default:
1812 			http_seterr(conn->err);
1813 			if (!verbose)
1814 				goto ouch;
1815 			/* fall through so we can get the full error message */
1816 		}
1817 
1818 		/* get headers. http_next_header expects one line readahead */
1819 		if (fetch_getln(conn) == -1) {
1820 			fetch_syserr();
1821 			goto ouch;
1822 		}
1823 		do {
1824 			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1825 			case hdr_syserror:
1826 				fetch_syserr();
1827 				goto ouch;
1828 			case hdr_error:
1829 				http_seterr(HTTP_PROTOCOL_ERROR);
1830 				goto ouch;
1831 			case hdr_content_length:
1832 				http_parse_length(p, &clength);
1833 				break;
1834 			case hdr_content_range:
1835 				http_parse_range(p, &offset, &length, &size);
1836 				break;
1837 			case hdr_last_modified:
1838 				http_parse_mtime(p, &mtime);
1839 				break;
1840 			case hdr_location:
1841 				if (!HTTP_REDIRECT(conn->err))
1842 					break;
1843 				/*
1844 				 * if the A flag is set, we don't follow
1845 				 * temporary redirects.
1846 				 */
1847 				if (noredirect &&
1848 				    conn->err != HTTP_MOVED_PERM &&
1849 				    conn->err != HTTP_PERM_REDIRECT &&
1850 				    conn->err != HTTP_USE_PROXY) {
1851 					n = 1;
1852 					break;
1853 				}
1854 				if (new)
1855 					free(new);
1856 				if (verbose)
1857 					fetch_info("%d redirect to %s",
1858 					    conn->err, p);
1859 				if (*p == '/')
1860 					/* absolute path */
1861 					new = fetchMakeURL(url->scheme, url->host,
1862 					    url->port, p, url->user, url->pwd);
1863 				else
1864 					new = fetchParseURL(p);
1865 				if (new == NULL) {
1866 					/* XXX should set an error code */
1867 					DEBUGF("failed to parse new URL\n");
1868 					goto ouch;
1869 				}
1870 
1871 				/* Only copy credentials if the host matches */
1872 				if (strcmp(new->host, url->host) == 0 &&
1873 				    !*new->user && !*new->pwd) {
1874 					strcpy(new->user, url->user);
1875 					strcpy(new->pwd, url->pwd);
1876 				}
1877 				new->offset = url->offset;
1878 				new->length = url->length;
1879 				new->ims_time = url->ims_time;
1880 				break;
1881 			case hdr_transfer_encoding:
1882 				/* XXX weak test*/
1883 				chunked = (strcasecmp(p, "chunked") == 0);
1884 				break;
1885 			case hdr_www_authenticate:
1886 				if (conn->err != HTTP_NEED_AUTH)
1887 					break;
1888 				if (http_parse_authenticate(p, &server_challenges) == 0)
1889 					++n;
1890 				break;
1891 			case hdr_proxy_authenticate:
1892 				if (conn->err != HTTP_NEED_PROXY_AUTH)
1893 					break;
1894 				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1895 					++n;
1896 				break;
1897 			case hdr_end:
1898 				/* fall through */
1899 			case hdr_unknown:
1900 				/* ignore */
1901 				break;
1902 			}
1903 		} while (h > hdr_end);
1904 
1905 		/* we need to provide authentication */
1906 		if (conn->err == HTTP_NEED_AUTH ||
1907 		    conn->err == HTTP_NEED_PROXY_AUTH) {
1908 			e = conn->err;
1909 			if ((conn->err == HTTP_NEED_AUTH &&
1910 			     !server_challenges.valid) ||
1911 			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1912 			     !proxy_challenges.valid)) {
1913 				/* 401/7 but no www/proxy-authenticate ?? */
1914 				DEBUGF("%03d without auth header\n", conn->err);
1915 				goto ouch;
1916 			}
1917 			fetch_close(conn);
1918 			conn = NULL;
1919 			continue;
1920 		}
1921 
1922 		/* requested range not satisfiable */
1923 		if (conn->err == HTTP_BAD_RANGE) {
1924 			if (url->offset > 0 && url->length == 0) {
1925 				/* asked for 0 bytes; fake it */
1926 				offset = url->offset;
1927 				clength = -1;
1928 				conn->err = HTTP_OK;
1929 				break;
1930 			} else {
1931 				http_seterr(conn->err);
1932 				goto ouch;
1933 			}
1934 		}
1935 
1936 		/* we have a hit or an error */
1937 		if (conn->err == HTTP_OK
1938 		    || conn->err == HTTP_NOT_MODIFIED
1939 		    || conn->err == HTTP_PARTIAL
1940 		    || HTTP_ERROR(conn->err))
1941 			break;
1942 
1943 		/* all other cases: we got a redirect */
1944 		e = conn->err;
1945 		clean_http_auth_challenges(&server_challenges);
1946 		fetch_close(conn);
1947 		conn = NULL;
1948 		if (!new) {
1949 			DEBUGF("redirect with no new location\n");
1950 			break;
1951 		}
1952 		if (url != URL)
1953 			fetchFreeURL(url);
1954 		url = new;
1955 	} while (++i < n);
1956 
1957 	/* we failed, or ran out of retries */
1958 	if (conn == NULL) {
1959 		http_seterr(e);
1960 		goto ouch;
1961 	}
1962 
1963 	DEBUGF("offset %lld, length %lld, size %lld, clength %lld\n",
1964 	    (long long)offset, (long long)length,
1965 	    (long long)size, (long long)clength);
1966 
1967 	if (conn->err == HTTP_NOT_MODIFIED) {
1968 		http_seterr(HTTP_NOT_MODIFIED);
1969 		return (NULL);
1970 	}
1971 
1972 	/* check for inconsistencies */
1973 	if (clength != -1 && length != -1 && clength != length) {
1974 		http_seterr(HTTP_PROTOCOL_ERROR);
1975 		goto ouch;
1976 	}
1977 	if (clength == -1)
1978 		clength = length;
1979 	if (clength != -1)
1980 		length = offset + clength;
1981 	if (length != -1 && size != -1 && length != size) {
1982 		http_seterr(HTTP_PROTOCOL_ERROR);
1983 		goto ouch;
1984 	}
1985 	if (size == -1)
1986 		size = length;
1987 
1988 	/* fill in stats */
1989 	if (us) {
1990 		us->size = size;
1991 		us->atime = us->mtime = mtime;
1992 	}
1993 
1994 	/* too far? */
1995 	if (URL->offset > 0 && offset > URL->offset) {
1996 		http_seterr(HTTP_PROTOCOL_ERROR);
1997 		goto ouch;
1998 	}
1999 
2000 	/* report back real offset and size */
2001 	URL->offset = offset;
2002 	URL->length = clength;
2003 
2004 	/* wrap it up in a FILE */
2005 	if ((f = http_funopen(conn, chunked)) == NULL) {
2006 		fetch_syserr();
2007 		goto ouch;
2008 	}
2009 
2010 	if (url != URL)
2011 		fetchFreeURL(url);
2012 	if (purl)
2013 		fetchFreeURL(purl);
2014 
2015 	if (HTTP_ERROR(conn->err)) {
2016 		http_print_html(stderr, f);
2017 		fclose(f);
2018 		f = NULL;
2019 	}
2020 	clean_http_headerbuf(&headerbuf);
2021 	clean_http_auth_challenges(&server_challenges);
2022 	clean_http_auth_challenges(&proxy_challenges);
2023 	return (f);
2024 
2025 ouch:
2026 	if (url != URL)
2027 		fetchFreeURL(url);
2028 	if (purl)
2029 		fetchFreeURL(purl);
2030 	if (conn != NULL)
2031 		fetch_close(conn);
2032 	clean_http_headerbuf(&headerbuf);
2033 	clean_http_auth_challenges(&server_challenges);
2034 	clean_http_auth_challenges(&proxy_challenges);
2035 	return (NULL);
2036 }
2037 
2038 
2039 /*****************************************************************************
2040  * Entry points
2041  */
2042 
2043 /*
2044  * Retrieve and stat a file by HTTP
2045  */
2046 FILE *
2047 fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
2048 {
2049 	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
2050 }
2051 
2052 /*
2053  * Retrieve a file by HTTP
2054  */
2055 FILE *
2056 fetchGetHTTP(struct url *URL, const char *flags)
2057 {
2058 	return (fetchXGetHTTP(URL, NULL, flags));
2059 }
2060 
2061 /*
2062  * Store a file by HTTP
2063  */
2064 FILE *
2065 fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2066 {
2067 	warnx("fetchPutHTTP(): not implemented");
2068 	return (NULL);
2069 }
2070 
2071 /*
2072  * Get an HTTP document's metadata
2073  */
2074 int
2075 fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2076 {
2077 	FILE *f;
2078 
2079 	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2080 	if (f == NULL)
2081 		return (-1);
2082 	fclose(f);
2083 	return (0);
2084 }
2085 
2086 /*
2087  * List a directory
2088  */
2089 struct url_ent *
2090 fetchListHTTP(struct url *url __unused, const char *flags __unused)
2091 {
2092 	warnx("fetchListHTTP(): not implemented");
2093 	return (NULL);
2094 }
2095 
2096 FILE *
2097 fetchReqHTTP(struct url *URL, const char *method, const char *flags,
2098 	const char *content_type, const char *body)
2099 {
2100 
2101 	return (http_request_body(URL, method, NULL, http_get_proxy(URL, flags),
2102 	    flags, content_type, body));
2103 }
2104