xref: /freebsd/lib/libfetch/http.c (revision 7431dfd4580e850375fe5478d92ec770344db098)
1 /*-
2  * Copyright (c) 2000-2014 Dag-Erling Smørgrav
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 /*
33  * The following copyright applies to the base64 code:
34  *
35  *-
36  * Copyright 1997 Massachusetts Institute of Technology
37  *
38  * Permission to use, copy, modify, and distribute this software and
39  * its documentation for any purpose and without fee is hereby
40  * granted, provided that both the above copyright notice and this
41  * permission notice appear in all copies, that both the above
42  * copyright notice and this permission notice appear in all
43  * supporting documentation, and that the name of M.I.T. not be used
44  * in advertising or publicity pertaining to distribution of the
45  * software without specific, written prior permission.  M.I.T. makes
46  * no representations about the suitability of this software for any
47  * purpose.  It is provided "as is" without express or implied
48  * warranty.
49  *
50  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
51  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
52  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
53  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
54  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
55  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
56  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
57  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
58  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
59  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
60  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  */
63 
64 #include <sys/param.h>
65 #include <sys/socket.h>
66 #include <sys/time.h>
67 
68 #include <ctype.h>
69 #include <err.h>
70 #include <errno.h>
71 #include <locale.h>
72 #include <netdb.h>
73 #include <stdarg.h>
74 #include <stdio.h>
75 #include <stdlib.h>
76 #include <string.h>
77 #include <time.h>
78 #include <unistd.h>
79 
80 #ifdef WITH_SSL
81 #include <openssl/md5.h>
82 #define MD5Init(c) MD5_Init(c)
83 #define MD5Update(c, data, len) MD5_Update(c, data, len)
84 #define MD5Final(md, c) MD5_Final(md, c)
85 #else
86 #include <md5.h>
87 #endif
88 
89 #include <netinet/in.h>
90 #include <netinet/tcp.h>
91 
92 #include "fetch.h"
93 #include "common.h"
94 #include "httperr.h"
95 
96 /* Maximum number of redirects to follow */
97 #define MAX_REDIRECT 20
98 
99 /* Symbolic names for reply codes we care about */
100 #define HTTP_OK			200
101 #define HTTP_PARTIAL		206
102 #define HTTP_MOVED_PERM		301
103 #define HTTP_MOVED_TEMP		302
104 #define HTTP_SEE_OTHER		303
105 #define HTTP_NOT_MODIFIED	304
106 #define HTTP_USE_PROXY		305
107 #define HTTP_TEMP_REDIRECT	307
108 #define HTTP_PERM_REDIRECT	308
109 #define HTTP_NEED_AUTH		401
110 #define HTTP_NEED_PROXY_AUTH	407
111 #define HTTP_BAD_RANGE		416
112 #define HTTP_PROTOCOL_ERROR	999
113 
114 #define HTTP_REDIRECT(xyz) ((xyz) == HTTP_MOVED_PERM \
115 			    || (xyz) == HTTP_MOVED_TEMP \
116 			    || (xyz) == HTTP_TEMP_REDIRECT \
117 			    || (xyz) == HTTP_USE_PROXY \
118 			    || (xyz) == HTTP_SEE_OTHER)
119 
120 #define HTTP_ERROR(xyz) ((xyz) > 400 && (xyz) < 599)
121 
122 
123 /*****************************************************************************
124  * I/O functions for decoding chunked streams
125  */
126 
127 struct httpio
128 {
129 	conn_t		*conn;		/* connection */
130 	int		 chunked;	/* chunked mode */
131 	char		*buf;		/* chunk buffer */
132 	size_t		 bufsize;	/* size of chunk buffer */
133 	ssize_t		 buflen;	/* amount of data currently in buffer */
134 	int		 bufpos;	/* current read offset in buffer */
135 	int		 eof;		/* end-of-file flag */
136 	int		 error;		/* error flag */
137 	size_t		 chunksize;	/* remaining size of current chunk */
138 #ifndef NDEBUG
139 	size_t		 total;
140 #endif
141 };
142 
143 /*
144  * Get next chunk header
145  */
146 static int
147 http_new_chunk(struct httpio *io)
148 {
149 	char *p;
150 
151 	if (fetch_getln(io->conn) == -1)
152 		return (-1);
153 
154 	if (io->conn->buflen < 2 || !isxdigit((unsigned char)*io->conn->buf))
155 		return (-1);
156 
157 	for (p = io->conn->buf; *p && !isspace((unsigned char)*p); ++p) {
158 		if (*p == ';')
159 			break;
160 		if (!isxdigit((unsigned char)*p))
161 			return (-1);
162 		if (isdigit((unsigned char)*p)) {
163 			io->chunksize = io->chunksize * 16 +
164 			    *p - '0';
165 		} else {
166 			io->chunksize = io->chunksize * 16 +
167 			    10 + tolower((unsigned char)*p) - 'a';
168 		}
169 	}
170 
171 #ifndef NDEBUG
172 	if (fetchDebug) {
173 		io->total += io->chunksize;
174 		if (io->chunksize == 0)
175 			fprintf(stderr, "%s(): end of last chunk\n", __func__);
176 		else
177 			fprintf(stderr, "%s(): new chunk: %lu (%lu)\n",
178 			    __func__, (unsigned long)io->chunksize,
179 			    (unsigned long)io->total);
180 	}
181 #endif
182 
183 	return (io->chunksize);
184 }
185 
186 /*
187  * Grow the input buffer to at least len bytes
188  */
189 static inline int
190 http_growbuf(struct httpio *io, size_t len)
191 {
192 	char *tmp;
193 
194 	if (io->bufsize >= len)
195 		return (0);
196 
197 	if ((tmp = realloc(io->buf, len)) == NULL)
198 		return (-1);
199 	io->buf = tmp;
200 	io->bufsize = len;
201 	return (0);
202 }
203 
204 /*
205  * Fill the input buffer, do chunk decoding on the fly
206  */
207 static ssize_t
208 http_fillbuf(struct httpio *io, size_t len)
209 {
210 	ssize_t nbytes;
211 	char ch;
212 
213 	if (io->error)
214 		return (-1);
215 	if (io->eof)
216 		return (0);
217 
218 	if (io->chunked == 0) {
219 		if (http_growbuf(io, len) == -1)
220 			return (-1);
221 		if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
222 			io->error = errno;
223 			return (-1);
224 		}
225 		io->buflen = nbytes;
226 		io->bufpos = 0;
227 		return (io->buflen);
228 	}
229 
230 	if (io->chunksize == 0) {
231 		switch (http_new_chunk(io)) {
232 		case -1:
233 			io->error = EPROTO;
234 			return (-1);
235 		case 0:
236 			io->eof = 1;
237 			return (0);
238 		}
239 	}
240 
241 	if (len > io->chunksize)
242 		len = io->chunksize;
243 	if (http_growbuf(io, len) == -1)
244 		return (-1);
245 	if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
246 		io->error = errno;
247 		return (-1);
248 	}
249 	io->buflen = nbytes;
250 	io->chunksize -= io->buflen;
251 
252 	if (io->chunksize == 0) {
253 		if (fetch_read(io->conn, &ch, 1) != 1 || ch != '\r' ||
254 		    fetch_read(io->conn, &ch, 1) != 1 || ch != '\n')
255 			return (-1);
256 	}
257 
258 	io->bufpos = 0;
259 
260 	return (io->buflen);
261 }
262 
263 /*
264  * Read function
265  */
266 static int
267 http_readfn(void *v, char *buf, int len)
268 {
269 	struct httpio *io = (struct httpio *)v;
270 	int rlen;
271 
272 	if (io->error)
273 		return (-1);
274 	if (io->eof)
275 		return (0);
276 
277 	/* empty buffer */
278 	if (!io->buf || io->bufpos == io->buflen) {
279 		if ((rlen = http_fillbuf(io, len)) < 0) {
280 			if ((errno = io->error) == EINTR)
281 				io->error = 0;
282 			return (-1);
283 		} else if (rlen == 0) {
284 			return (0);
285 		}
286 	}
287 
288 	rlen = io->buflen - io->bufpos;
289 	if (len < rlen)
290 		rlen = len;
291 	memcpy(buf, io->buf + io->bufpos, rlen);
292 	io->bufpos += rlen;
293 	return (rlen);
294 }
295 
296 /*
297  * Write function
298  */
299 static int
300 http_writefn(void *v, const char *buf, int len)
301 {
302 	struct httpio *io = (struct httpio *)v;
303 
304 	return (fetch_write(io->conn, buf, len));
305 }
306 
307 /*
308  * Close function
309  */
310 static int
311 http_closefn(void *v)
312 {
313 	struct httpio *io = (struct httpio *)v;
314 	int r;
315 
316 	r = fetch_close(io->conn);
317 	if (io->buf)
318 		free(io->buf);
319 	free(io);
320 	return (r);
321 }
322 
323 /*
324  * Wrap a file descriptor up
325  */
326 static FILE *
327 http_funopen(conn_t *conn, int chunked)
328 {
329 	struct httpio *io;
330 	FILE *f;
331 
332 	if ((io = calloc(1, sizeof(*io))) == NULL) {
333 		fetch_syserr();
334 		return (NULL);
335 	}
336 	io->conn = conn;
337 	io->chunked = chunked;
338 	f = funopen(io, http_readfn, http_writefn, NULL, http_closefn);
339 	if (f == NULL) {
340 		fetch_syserr();
341 		free(io);
342 		return (NULL);
343 	}
344 	return (f);
345 }
346 
347 
348 /*****************************************************************************
349  * Helper functions for talking to the server and parsing its replies
350  */
351 
352 /* Header types */
353 typedef enum {
354 	hdr_syserror = -2,
355 	hdr_error = -1,
356 	hdr_end = 0,
357 	hdr_unknown = 1,
358 	hdr_content_length,
359 	hdr_content_range,
360 	hdr_last_modified,
361 	hdr_location,
362 	hdr_transfer_encoding,
363 	hdr_www_authenticate,
364 	hdr_proxy_authenticate,
365 } hdr_t;
366 
367 /* Names of interesting headers */
368 static struct {
369 	hdr_t		 num;
370 	const char	*name;
371 } hdr_names[] = {
372 	{ hdr_content_length,		"Content-Length" },
373 	{ hdr_content_range,		"Content-Range" },
374 	{ hdr_last_modified,		"Last-Modified" },
375 	{ hdr_location,			"Location" },
376 	{ hdr_transfer_encoding,	"Transfer-Encoding" },
377 	{ hdr_www_authenticate,		"WWW-Authenticate" },
378 	{ hdr_proxy_authenticate,	"Proxy-Authenticate" },
379 	{ hdr_unknown,			NULL },
380 };
381 
382 /*
383  * Send a formatted line; optionally echo to terminal
384  */
385 static int
386 http_cmd(conn_t *conn, const char *fmt, ...)
387 {
388 	va_list ap;
389 	size_t len;
390 	char *msg;
391 	int r;
392 
393 	va_start(ap, fmt);
394 	len = vasprintf(&msg, fmt, ap);
395 	va_end(ap);
396 
397 	if (msg == NULL) {
398 		errno = ENOMEM;
399 		fetch_syserr();
400 		return (-1);
401 	}
402 
403 	r = fetch_putln(conn, msg, len);
404 	free(msg);
405 
406 	if (r == -1) {
407 		fetch_syserr();
408 		return (-1);
409 	}
410 
411 	return (0);
412 }
413 
414 /*
415  * Get and parse status line
416  */
417 static int
418 http_get_reply(conn_t *conn)
419 {
420 	char *p;
421 
422 	if (fetch_getln(conn) == -1)
423 		return (-1);
424 	/*
425 	 * A valid status line looks like "HTTP/m.n xyz reason" where m
426 	 * and n are the major and minor protocol version numbers and xyz
427 	 * is the reply code.
428 	 * Unfortunately, there are servers out there (NCSA 1.5.1, to name
429 	 * just one) that do not send a version number, so we can't rely
430 	 * on finding one, but if we do, insist on it being 1.0 or 1.1.
431 	 * We don't care about the reason phrase.
432 	 */
433 	if (strncmp(conn->buf, "HTTP", 4) != 0)
434 		return (HTTP_PROTOCOL_ERROR);
435 	p = conn->buf + 4;
436 	if (*p == '/') {
437 		if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
438 			return (HTTP_PROTOCOL_ERROR);
439 		p += 4;
440 	}
441 	if (*p != ' ' ||
442 	    !isdigit((unsigned char)p[1]) ||
443 	    !isdigit((unsigned char)p[2]) ||
444 	    !isdigit((unsigned char)p[3]))
445 		return (HTTP_PROTOCOL_ERROR);
446 
447 	conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
448 	return (conn->err);
449 }
450 
451 /*
452  * Check a header; if the type matches the given string, return a pointer
453  * to the beginning of the value.
454  */
455 static const char *
456 http_match(const char *str, const char *hdr)
457 {
458 	while (*str && *hdr &&
459 	    tolower((unsigned char)*str++) == tolower((unsigned char)*hdr++))
460 		/* nothing */;
461 	if (*str || *hdr != ':')
462 		return (NULL);
463 	while (*hdr && isspace((unsigned char)*++hdr))
464 		/* nothing */;
465 	return (hdr);
466 }
467 
468 
469 /*
470  * Get the next header and return the appropriate symbolic code.  We
471  * need to read one line ahead for checking for a continuation line
472  * belonging to the current header (continuation lines start with
473  * white space).
474  *
475  * We get called with a fresh line already in the conn buffer, either
476  * from the previous http_next_header() invocation, or, the first
477  * time, from a fetch_getln() performed by our caller.
478  *
479  * This stops when we encounter an empty line (we dont read beyond the header
480  * area).
481  *
482  * Note that the "headerbuf" is just a place to return the result. Its
483  * contents are not used for the next call. This means that no cleanup
484  * is needed when ie doing another connection, just call the cleanup when
485  * fully done to deallocate memory.
486  */
487 
488 /* Limit the max number of continuation lines to some reasonable value */
489 #define HTTP_MAX_CONT_LINES 10
490 
491 /* Place into which to build a header from one or several lines */
492 typedef struct {
493 	char	*buf;		/* buffer */
494 	size_t	 bufsize;	/* buffer size */
495 	size_t	 buflen;	/* length of buffer contents */
496 } http_headerbuf_t;
497 
498 static void
499 init_http_headerbuf(http_headerbuf_t *buf)
500 {
501 	buf->buf = NULL;
502 	buf->bufsize = 0;
503 	buf->buflen = 0;
504 }
505 
506 static void
507 clean_http_headerbuf(http_headerbuf_t *buf)
508 {
509 	if (buf->buf)
510 		free(buf->buf);
511 	init_http_headerbuf(buf);
512 }
513 
514 /* Remove whitespace at the end of the buffer */
515 static void
516 http_conn_trimright(conn_t *conn)
517 {
518 	while (conn->buflen &&
519 	       isspace((unsigned char)conn->buf[conn->buflen - 1]))
520 		conn->buflen--;
521 	conn->buf[conn->buflen] = '\0';
522 }
523 
524 static hdr_t
525 http_next_header(conn_t *conn, http_headerbuf_t *hbuf, const char **p)
526 {
527 	unsigned int i, len;
528 
529 	/*
530 	 * Have to do the stripping here because of the first line. So
531 	 * it's done twice for the subsequent lines. No big deal
532 	 */
533 	http_conn_trimright(conn);
534 	if (conn->buflen == 0)
535 		return (hdr_end);
536 
537 	/* Copy the line to the headerbuf */
538 	if (hbuf->bufsize < conn->buflen + 1) {
539 		if ((hbuf->buf = realloc(hbuf->buf, conn->buflen + 1)) == NULL)
540 			return (hdr_syserror);
541 		hbuf->bufsize = conn->buflen + 1;
542 	}
543 	strcpy(hbuf->buf, conn->buf);
544 	hbuf->buflen = conn->buflen;
545 
546 	/*
547 	 * Fetch possible continuation lines. Stop at 1st non-continuation
548 	 * and leave it in the conn buffer
549 	 */
550 	for (i = 0; i < HTTP_MAX_CONT_LINES; i++) {
551 		if (fetch_getln(conn) == -1)
552 			return (hdr_syserror);
553 
554 		/*
555 		 * Note: we carry on the idea from the previous version
556 		 * that a pure whitespace line is equivalent to an empty
557 		 * one (so it's not continuation and will be handled when
558 		 * we are called next)
559 		 */
560 		http_conn_trimright(conn);
561 		if (conn->buf[0] != ' ' && conn->buf[0] != "\t"[0])
562 			break;
563 
564 		/* Got a continuation line. Concatenate to previous */
565 		len = hbuf->buflen + conn->buflen;
566 		if (hbuf->bufsize < len + 1) {
567 			len *= 2;
568 			if ((hbuf->buf = realloc(hbuf->buf, len + 1)) == NULL)
569 				return (hdr_syserror);
570 			hbuf->bufsize = len + 1;
571 		}
572 		strcpy(hbuf->buf + hbuf->buflen, conn->buf);
573 		hbuf->buflen += conn->buflen;
574 	}
575 
576 	/*
577 	 * We could check for malformed headers but we don't really care.
578 	 * A valid header starts with a token immediately followed by a
579 	 * colon; a token is any sequence of non-control, non-whitespace
580 	 * characters except "()<>@,;:\\\"{}".
581 	 */
582 	for (i = 0; hdr_names[i].num != hdr_unknown; i++)
583 		if ((*p = http_match(hdr_names[i].name, hbuf->buf)) != NULL)
584 			return (hdr_names[i].num);
585 
586 	return (hdr_unknown);
587 }
588 
589 /**************************
590  * [Proxy-]Authenticate header parsing
591  */
592 
593 /*
594  * Read doublequote-delimited string into output buffer obuf (allocated
595  * by caller, whose responsibility it is to ensure that it's big enough)
596  * cp points to the first char after the initial '"'
597  * Handles \ quoting
598  * Returns pointer to the first char after the terminating double quote, or
599  * NULL for error.
600  */
601 static const char *
602 http_parse_headerstring(const char *cp, char *obuf)
603 {
604 	for (;;) {
605 		switch (*cp) {
606 		case 0: /* Unterminated string */
607 			*obuf = 0;
608 			return (NULL);
609 		case '"': /* Ending quote */
610 			*obuf = 0;
611 			return (++cp);
612 		case '\\':
613 			if (*++cp == 0) {
614 				*obuf = 0;
615 				return (NULL);
616 			}
617 			/* FALLTHROUGH */
618 		default:
619 			*obuf++ = *cp++;
620 		}
621 	}
622 }
623 
624 /* Http auth challenge schemes */
625 typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
626 
627 /* Data holder for a Basic or Digest challenge. */
628 typedef struct {
629 	http_auth_schemes_t scheme;
630 	char	*realm;
631 	char	*qop;
632 	char	*nonce;
633 	char	*opaque;
634 	char	*algo;
635 	int	 stale;
636 	int	 nc; /* Nonce count */
637 } http_auth_challenge_t;
638 
639 static void
640 init_http_auth_challenge(http_auth_challenge_t *b)
641 {
642 	b->scheme = HTTPAS_UNKNOWN;
643 	b->realm = b->qop = b->nonce = b->opaque = b->algo = NULL;
644 	b->stale = b->nc = 0;
645 }
646 
647 static void
648 clean_http_auth_challenge(http_auth_challenge_t *b)
649 {
650 	if (b->realm)
651 		free(b->realm);
652 	if (b->qop)
653 		free(b->qop);
654 	if (b->nonce)
655 		free(b->nonce);
656 	if (b->opaque)
657 		free(b->opaque);
658 	if (b->algo)
659 		free(b->algo);
660 	init_http_auth_challenge(b);
661 }
662 
663 /* Data holder for an array of challenges offered in an http response. */
664 #define MAX_CHALLENGES 10
665 typedef struct {
666 	http_auth_challenge_t *challenges[MAX_CHALLENGES];
667 	int	count; /* Number of parsed challenges in the array */
668 	int	valid; /* We did parse an authenticate header */
669 } http_auth_challenges_t;
670 
671 static void
672 init_http_auth_challenges(http_auth_challenges_t *cs)
673 {
674 	int i;
675 	for (i = 0; i < MAX_CHALLENGES; i++)
676 		cs->challenges[i] = NULL;
677 	cs->count = cs->valid = 0;
678 }
679 
680 static void
681 clean_http_auth_challenges(http_auth_challenges_t *cs)
682 {
683 	int i;
684 	/* We rely on non-zero pointers being allocated, not on the count */
685 	for (i = 0; i < MAX_CHALLENGES; i++) {
686 		if (cs->challenges[i] != NULL) {
687 			clean_http_auth_challenge(cs->challenges[i]);
688 			free(cs->challenges[i]);
689 		}
690 	}
691 	init_http_auth_challenges(cs);
692 }
693 
694 /*
695  * Enumeration for lexical elements. Separators will be returned as their own
696  * ascii value
697  */
698 typedef enum {HTTPHL_WORD=256, HTTPHL_STRING=257, HTTPHL_END=258,
699 	      HTTPHL_ERROR = 259} http_header_lex_t;
700 
701 /*
702  * Determine what kind of token comes next and return possible value
703  * in buf, which is supposed to have been allocated big enough by
704  * caller. Advance input pointer and return element type.
705  */
706 static int
707 http_header_lex(const char **cpp, char *buf)
708 {
709 	size_t l;
710 	/* Eat initial whitespace */
711 	*cpp += strspn(*cpp, " \t");
712 	if (**cpp == 0)
713 		return (HTTPHL_END);
714 
715 	/* Separator ? */
716 	if (**cpp == ',' || **cpp == '=')
717 		return (*((*cpp)++));
718 
719 	/* String ? */
720 	if (**cpp == '"') {
721 		*cpp = http_parse_headerstring(++*cpp, buf);
722 		if (*cpp == NULL)
723 			return (HTTPHL_ERROR);
724 		return (HTTPHL_STRING);
725 	}
726 
727 	/* Read other token, until separator or whitespace */
728 	l = strcspn(*cpp, " \t,=");
729 	memcpy(buf, *cpp, l);
730 	buf[l] = 0;
731 	*cpp += l;
732 	return (HTTPHL_WORD);
733 }
734 
735 /*
736  * Read challenges from http xxx-authenticate header and accumulate them
737  * in the challenges list structure.
738  *
739  * Headers with multiple challenges are specified by rfc2617, but
740  * servers (ie: squid) often send them in separate headers instead,
741  * which in turn is forbidden by the http spec (multiple headers with
742  * the same name are only allowed for pure comma-separated lists, see
743  * rfc2616 sec 4.2).
744  *
745  * We support both approaches anyway
746  */
747 static int
748 http_parse_authenticate(const char *cp, http_auth_challenges_t *cs)
749 {
750 	int ret = -1;
751 	http_header_lex_t lex;
752 	char *key = malloc(strlen(cp) + 1);
753 	char *value = malloc(strlen(cp) + 1);
754 	char *buf = malloc(strlen(cp) + 1);
755 
756 	if (key == NULL || value == NULL || buf == NULL) {
757 		fetch_syserr();
758 		goto out;
759 	}
760 
761 	/* In any case we've seen the header and we set the valid bit */
762 	cs->valid = 1;
763 
764 	/* Need word first */
765 	lex = http_header_lex(&cp, key);
766 	if (lex != HTTPHL_WORD)
767 		goto out;
768 
769 	/* Loop on challenges */
770 	for (; cs->count < MAX_CHALLENGES; cs->count++) {
771 		cs->challenges[cs->count] =
772 			malloc(sizeof(http_auth_challenge_t));
773 		if (cs->challenges[cs->count] == NULL) {
774 			fetch_syserr();
775 			goto out;
776 		}
777 		init_http_auth_challenge(cs->challenges[cs->count]);
778 		if (!strcasecmp(key, "basic")) {
779 			cs->challenges[cs->count]->scheme = HTTPAS_BASIC;
780 		} else if (!strcasecmp(key, "digest")) {
781 			cs->challenges[cs->count]->scheme = HTTPAS_DIGEST;
782 		} else {
783 			cs->challenges[cs->count]->scheme = HTTPAS_UNKNOWN;
784 			/*
785 			 * Continue parsing as basic or digest may
786 			 * follow, and the syntax is the same for
787 			 * all. We'll just ignore this one when
788 			 * looking at the list
789 			 */
790 		}
791 
792 		/* Loop on attributes */
793 		for (;;) {
794 			/* Key */
795 			lex = http_header_lex(&cp, key);
796 			if (lex != HTTPHL_WORD)
797 				goto out;
798 
799 			/* Equal sign */
800 			lex = http_header_lex(&cp, buf);
801 			if (lex != '=')
802 				goto out;
803 
804 			/* Value */
805 			lex = http_header_lex(&cp, value);
806 			if (lex != HTTPHL_WORD && lex != HTTPHL_STRING)
807 				goto out;
808 
809 			if (!strcasecmp(key, "realm"))
810 				cs->challenges[cs->count]->realm =
811 					strdup(value);
812 			else if (!strcasecmp(key, "qop"))
813 				cs->challenges[cs->count]->qop =
814 					strdup(value);
815 			else if (!strcasecmp(key, "nonce"))
816 				cs->challenges[cs->count]->nonce =
817 					strdup(value);
818 			else if (!strcasecmp(key, "opaque"))
819 				cs->challenges[cs->count]->opaque =
820 					strdup(value);
821 			else if (!strcasecmp(key, "algorithm"))
822 				cs->challenges[cs->count]->algo =
823 					strdup(value);
824 			else if (!strcasecmp(key, "stale"))
825 				cs->challenges[cs->count]->stale =
826 					strcasecmp(value, "no");
827 			/* Else ignore unknown attributes */
828 
829 			/* Comma or Next challenge or End */
830 			lex = http_header_lex(&cp, key);
831 			/*
832 			 * If we get a word here, this is the beginning of the
833 			 * next challenge. Break the attributes loop
834 			 */
835 			if (lex == HTTPHL_WORD)
836 				break;
837 
838 			if (lex == HTTPHL_END) {
839 				/* End while looking for ',' is normal exit */
840 				cs->count++;
841 				ret = 0;
842 				goto out;
843 			}
844 			/* Anything else is an error */
845 			if (lex != ',')
846 				goto out;
847 
848 		} /* End attributes loop */
849 	} /* End challenge loop */
850 
851 	/*
852 	 * Challenges max count exceeded. This really can't happen
853 	 * with normal data, something's fishy -> error
854 	 */
855 
856 out:
857 	if (key)
858 		free(key);
859 	if (value)
860 		free(value);
861 	if (buf)
862 		free(buf);
863 	return (ret);
864 }
865 
866 
867 /*
868  * Parse a last-modified header
869  */
870 static int
871 http_parse_mtime(const char *p, time_t *mtime)
872 {
873 	char locale[64], *r;
874 	struct tm tm;
875 
876 	strncpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
877 	setlocale(LC_TIME, "C");
878 	r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
879 	/*
880 	 * Some proxies use UTC in response, but it should still be
881 	 * parsed. RFC2616 states GMT and UTC are exactly equal for HTTP.
882 	 */
883 	if (r == NULL)
884 		r = strptime(p, "%a, %d %b %Y %H:%M:%S UTC", &tm);
885 	/* XXX should add support for date-2 and date-3 */
886 	setlocale(LC_TIME, locale);
887 	if (r == NULL)
888 		return (-1);
889 	DEBUG(fprintf(stderr, "last modified: [%04d-%02d-%02d "
890 		  "%02d:%02d:%02d]\n",
891 		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
892 		  tm.tm_hour, tm.tm_min, tm.tm_sec));
893 	*mtime = timegm(&tm);
894 	return (0);
895 }
896 
897 /*
898  * Parse a content-length header
899  */
900 static int
901 http_parse_length(const char *p, off_t *length)
902 {
903 	off_t len;
904 
905 	for (len = 0; *p && isdigit((unsigned char)*p); ++p)
906 		len = len * 10 + (*p - '0');
907 	if (*p)
908 		return (-1);
909 	DEBUG(fprintf(stderr, "content length: [%lld]\n",
910 	    (long long)len));
911 	*length = len;
912 	return (0);
913 }
914 
915 /*
916  * Parse a content-range header
917  */
918 static int
919 http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
920 {
921 	off_t first, last, len;
922 
923 	if (strncasecmp(p, "bytes ", 6) != 0)
924 		return (-1);
925 	p += 6;
926 	if (*p == '*') {
927 		first = last = -1;
928 		++p;
929 	} else {
930 		for (first = 0; *p && isdigit((unsigned char)*p); ++p)
931 			first = first * 10 + *p - '0';
932 		if (*p != '-')
933 			return (-1);
934 		for (last = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
935 			last = last * 10 + *p - '0';
936 	}
937 	if (first > last || *p != '/')
938 		return (-1);
939 	for (len = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
940 		len = len * 10 + *p - '0';
941 	if (*p || len < last - first + 1)
942 		return (-1);
943 	if (first == -1) {
944 		DEBUG(fprintf(stderr, "content range: [*/%lld]\n",
945 		    (long long)len));
946 		*length = 0;
947 	} else {
948 		DEBUG(fprintf(stderr, "content range: [%lld-%lld/%lld]\n",
949 		    (long long)first, (long long)last, (long long)len));
950 		*length = last - first + 1;
951 	}
952 	*offset = first;
953 	*size = len;
954 	return (0);
955 }
956 
957 
958 /*****************************************************************************
959  * Helper functions for authorization
960  */
961 
962 /*
963  * Base64 encoding
964  */
965 static char *
966 http_base64(const char *src)
967 {
968 	static const char base64[] =
969 	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
970 	    "abcdefghijklmnopqrstuvwxyz"
971 	    "0123456789+/";
972 	char *str, *dst;
973 	size_t l;
974 	int t, r;
975 
976 	l = strlen(src);
977 	if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
978 		return (NULL);
979 	dst = str;
980 	r = 0;
981 
982 	while (l >= 3) {
983 		t = (src[0] << 16) | (src[1] << 8) | src[2];
984 		dst[0] = base64[(t >> 18) & 0x3f];
985 		dst[1] = base64[(t >> 12) & 0x3f];
986 		dst[2] = base64[(t >> 6) & 0x3f];
987 		dst[3] = base64[(t >> 0) & 0x3f];
988 		src += 3; l -= 3;
989 		dst += 4; r += 4;
990 	}
991 
992 	switch (l) {
993 	case 2:
994 		t = (src[0] << 16) | (src[1] << 8);
995 		dst[0] = base64[(t >> 18) & 0x3f];
996 		dst[1] = base64[(t >> 12) & 0x3f];
997 		dst[2] = base64[(t >> 6) & 0x3f];
998 		dst[3] = '=';
999 		dst += 4;
1000 		r += 4;
1001 		break;
1002 	case 1:
1003 		t = src[0] << 16;
1004 		dst[0] = base64[(t >> 18) & 0x3f];
1005 		dst[1] = base64[(t >> 12) & 0x3f];
1006 		dst[2] = dst[3] = '=';
1007 		dst += 4;
1008 		r += 4;
1009 		break;
1010 	case 0:
1011 		break;
1012 	}
1013 
1014 	*dst = 0;
1015 	return (str);
1016 }
1017 
1018 
1019 /*
1020  * Extract authorization parameters from environment value.
1021  * The value is like scheme:realm:user:pass
1022  */
1023 typedef struct {
1024 	char	*scheme;
1025 	char	*realm;
1026 	char	*user;
1027 	char	*password;
1028 } http_auth_params_t;
1029 
1030 static void
1031 init_http_auth_params(http_auth_params_t *s)
1032 {
1033 	s->scheme = s->realm = s->user = s->password = NULL;
1034 }
1035 
1036 static void
1037 clean_http_auth_params(http_auth_params_t *s)
1038 {
1039 	if (s->scheme)
1040 		free(s->scheme);
1041 	if (s->realm)
1042 		free(s->realm);
1043 	if (s->user)
1044 		free(s->user);
1045 	if (s->password)
1046 		free(s->password);
1047 	init_http_auth_params(s);
1048 }
1049 
1050 static int
1051 http_authfromenv(const char *p, http_auth_params_t *parms)
1052 {
1053 	int ret = -1;
1054 	char *v, *ve;
1055 	char *str = strdup(p);
1056 
1057 	if (str == NULL) {
1058 		fetch_syserr();
1059 		return (-1);
1060 	}
1061 	v = str;
1062 
1063 	if ((ve = strchr(v, ':')) == NULL)
1064 		goto out;
1065 
1066 	*ve = 0;
1067 	if ((parms->scheme = strdup(v)) == NULL) {
1068 		fetch_syserr();
1069 		goto out;
1070 	}
1071 	v = ve + 1;
1072 
1073 	if ((ve = strchr(v, ':')) == NULL)
1074 		goto out;
1075 
1076 	*ve = 0;
1077 	if ((parms->realm = strdup(v)) == NULL) {
1078 		fetch_syserr();
1079 		goto out;
1080 	}
1081 	v = ve + 1;
1082 
1083 	if ((ve = strchr(v, ':')) == NULL)
1084 		goto out;
1085 
1086 	*ve = 0;
1087 	if ((parms->user = strdup(v)) == NULL) {
1088 		fetch_syserr();
1089 		goto out;
1090 	}
1091 	v = ve + 1;
1092 
1093 
1094 	if ((parms->password = strdup(v)) == NULL) {
1095 		fetch_syserr();
1096 		goto out;
1097 	}
1098 	ret = 0;
1099 out:
1100 	if (ret == -1)
1101 		clean_http_auth_params(parms);
1102 	if (str)
1103 		free(str);
1104 	return (ret);
1105 }
1106 
1107 
1108 /*
1109  * Digest response: the code to compute the digest is taken from the
1110  * sample implementation in RFC2616
1111  */
1112 #define IN const
1113 #define OUT
1114 
1115 #define HASHLEN 16
1116 typedef char HASH[HASHLEN];
1117 #define HASHHEXLEN 32
1118 typedef char HASHHEX[HASHHEXLEN+1];
1119 
1120 static const char *hexchars = "0123456789abcdef";
1121 static void
1122 CvtHex(IN HASH Bin, OUT HASHHEX Hex)
1123 {
1124 	unsigned short i;
1125 	unsigned char j;
1126 
1127 	for (i = 0; i < HASHLEN; i++) {
1128 		j = (Bin[i] >> 4) & 0xf;
1129 		Hex[i*2] = hexchars[j];
1130 		j = Bin[i] & 0xf;
1131 		Hex[i*2+1] = hexchars[j];
1132 	}
1133 	Hex[HASHHEXLEN] = '\0';
1134 };
1135 
1136 /* calculate H(A1) as per spec */
1137 static void
1138 DigestCalcHA1(
1139 	IN char * pszAlg,
1140 	IN char * pszUserName,
1141 	IN char * pszRealm,
1142 	IN char * pszPassword,
1143 	IN char * pszNonce,
1144 	IN char * pszCNonce,
1145 	OUT HASHHEX SessionKey
1146 	)
1147 {
1148 	MD5_CTX Md5Ctx;
1149 	HASH HA1;
1150 
1151 	MD5Init(&Md5Ctx);
1152 	MD5Update(&Md5Ctx, pszUserName, strlen(pszUserName));
1153 	MD5Update(&Md5Ctx, ":", 1);
1154 	MD5Update(&Md5Ctx, pszRealm, strlen(pszRealm));
1155 	MD5Update(&Md5Ctx, ":", 1);
1156 	MD5Update(&Md5Ctx, pszPassword, strlen(pszPassword));
1157 	MD5Final(HA1, &Md5Ctx);
1158 	if (strcasecmp(pszAlg, "md5-sess") == 0) {
1159 
1160 		MD5Init(&Md5Ctx);
1161 		MD5Update(&Md5Ctx, HA1, HASHLEN);
1162 		MD5Update(&Md5Ctx, ":", 1);
1163 		MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1164 		MD5Update(&Md5Ctx, ":", 1);
1165 		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1166 		MD5Final(HA1, &Md5Ctx);
1167 	}
1168 	CvtHex(HA1, SessionKey);
1169 }
1170 
1171 /* calculate request-digest/response-digest as per HTTP Digest spec */
1172 static void
1173 DigestCalcResponse(
1174 	IN HASHHEX HA1,           /* H(A1) */
1175 	IN char * pszNonce,       /* nonce from server */
1176 	IN char * pszNonceCount,  /* 8 hex digits */
1177 	IN char * pszCNonce,      /* client nonce */
1178 	IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
1179 	IN char * pszMethod,      /* method from the request */
1180 	IN char * pszDigestUri,   /* requested URL */
1181 	IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
1182 	OUT HASHHEX Response      /* request-digest or response-digest */
1183 	)
1184 {
1185 /*	DEBUG(fprintf(stderr,
1186 		      "Calc: HA1[%s] Nonce[%s] qop[%s] method[%s] URI[%s]\n",
1187 		      HA1, pszNonce, pszQop, pszMethod, pszDigestUri));*/
1188 	MD5_CTX Md5Ctx;
1189 	HASH HA2;
1190 	HASH RespHash;
1191 	HASHHEX HA2Hex;
1192 
1193 	// calculate H(A2)
1194 	MD5Init(&Md5Ctx);
1195 	MD5Update(&Md5Ctx, pszMethod, strlen(pszMethod));
1196 	MD5Update(&Md5Ctx, ":", 1);
1197 	MD5Update(&Md5Ctx, pszDigestUri, strlen(pszDigestUri));
1198 	if (strcasecmp(pszQop, "auth-int") == 0) {
1199 		MD5Update(&Md5Ctx, ":", 1);
1200 		MD5Update(&Md5Ctx, HEntity, HASHHEXLEN);
1201 	}
1202 	MD5Final(HA2, &Md5Ctx);
1203 	CvtHex(HA2, HA2Hex);
1204 
1205 	// calculate response
1206 	MD5Init(&Md5Ctx);
1207 	MD5Update(&Md5Ctx, HA1, HASHHEXLEN);
1208 	MD5Update(&Md5Ctx, ":", 1);
1209 	MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1210 	MD5Update(&Md5Ctx, ":", 1);
1211 	if (*pszQop) {
1212 		MD5Update(&Md5Ctx, pszNonceCount, strlen(pszNonceCount));
1213 		MD5Update(&Md5Ctx, ":", 1);
1214 		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1215 		MD5Update(&Md5Ctx, ":", 1);
1216 		MD5Update(&Md5Ctx, pszQop, strlen(pszQop));
1217 		MD5Update(&Md5Ctx, ":", 1);
1218 	}
1219 	MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
1220 	MD5Final(RespHash, &Md5Ctx);
1221 	CvtHex(RespHash, Response);
1222 }
1223 
1224 /*
1225  * Generate/Send a Digest authorization header
1226  * This looks like: [Proxy-]Authorization: credentials
1227  *
1228  *  credentials      = "Digest" digest-response
1229  *  digest-response  = 1#( username | realm | nonce | digest-uri
1230  *                      | response | [ algorithm ] | [cnonce] |
1231  *                      [opaque] | [message-qop] |
1232  *                          [nonce-count]  | [auth-param] )
1233  *  username         = "username" "=" username-value
1234  *  username-value   = quoted-string
1235  *  digest-uri       = "uri" "=" digest-uri-value
1236  *  digest-uri-value = request-uri   ; As specified by HTTP/1.1
1237  *  message-qop      = "qop" "=" qop-value
1238  *  cnonce           = "cnonce" "=" cnonce-value
1239  *  cnonce-value     = nonce-value
1240  *  nonce-count      = "nc" "=" nc-value
1241  *  nc-value         = 8LHEX
1242  *  response         = "response" "=" request-digest
1243  *  request-digest = <"> 32LHEX <">
1244  */
1245 static int
1246 http_digest_auth(conn_t *conn, const char *hdr, http_auth_challenge_t *c,
1247 		 http_auth_params_t *parms, struct url *url)
1248 {
1249 	int r;
1250 	char noncecount[10];
1251 	char cnonce[40];
1252 	char *options = NULL;
1253 
1254 	if (!c->realm || !c->nonce) {
1255 		DEBUG(fprintf(stderr, "realm/nonce not set in challenge\n"));
1256 		return(-1);
1257 	}
1258 	if (!c->algo)
1259 		c->algo = strdup("");
1260 
1261 	if (asprintf(&options, "%s%s%s%s",
1262 		     *c->algo? ",algorithm=" : "", c->algo,
1263 		     c->opaque? ",opaque=" : "", c->opaque?c->opaque:"")== -1)
1264 		return (-1);
1265 
1266 	if (!c->qop) {
1267 		c->qop = strdup("");
1268 		*noncecount = 0;
1269 		*cnonce = 0;
1270 	} else {
1271 		c->nc++;
1272 		sprintf(noncecount, "%08x", c->nc);
1273 		/* We don't try very hard with the cnonce ... */
1274 		sprintf(cnonce, "%x%lx", getpid(), (unsigned long)time(0));
1275 	}
1276 
1277 	HASHHEX HA1;
1278 	DigestCalcHA1(c->algo, parms->user, c->realm,
1279 		      parms->password, c->nonce, cnonce, HA1);
1280 	DEBUG(fprintf(stderr, "HA1: [%s]\n", HA1));
1281 	HASHHEX digest;
1282 	DigestCalcResponse(HA1, c->nonce, noncecount, cnonce, c->qop,
1283 			   "GET", url->doc, "", digest);
1284 
1285 	if (c->qop[0]) {
1286 		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1287 			     "nonce=\"%s\",uri=\"%s\",response=\"%s\","
1288 			     "qop=\"auth\", cnonce=\"%s\", nc=%s%s",
1289 			     hdr, parms->user, c->realm,
1290 			     c->nonce, url->doc, digest,
1291 			     cnonce, noncecount, options);
1292 	} else {
1293 		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1294 			     "nonce=\"%s\",uri=\"%s\",response=\"%s\"%s",
1295 			     hdr, parms->user, c->realm,
1296 			     c->nonce, url->doc, digest, options);
1297 	}
1298 	if (options)
1299 		free(options);
1300 	return (r);
1301 }
1302 
1303 /*
1304  * Encode username and password
1305  */
1306 static int
1307 http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
1308 {
1309 	char *upw, *auth;
1310 	int r;
1311 
1312 	DEBUG(fprintf(stderr, "basic: usr: [%s]\n", usr));
1313 	DEBUG(fprintf(stderr, "basic: pwd: [%s]\n", pwd));
1314 	if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
1315 		return (-1);
1316 	auth = http_base64(upw);
1317 	free(upw);
1318 	if (auth == NULL)
1319 		return (-1);
1320 	r = http_cmd(conn, "%s: Basic %s", hdr, auth);
1321 	free(auth);
1322 	return (r);
1323 }
1324 
1325 /*
1326  * Chose the challenge to answer and call the appropriate routine to
1327  * produce the header.
1328  */
1329 static int
1330 http_authorize(conn_t *conn, const char *hdr, http_auth_challenges_t *cs,
1331 	       http_auth_params_t *parms, struct url *url)
1332 {
1333 	http_auth_challenge_t *basic = NULL;
1334 	http_auth_challenge_t *digest = NULL;
1335 	int i;
1336 
1337 	/* If user or pass are null we're not happy */
1338 	if (!parms->user || !parms->password) {
1339 		DEBUG(fprintf(stderr, "NULL usr or pass\n"));
1340 		return (-1);
1341 	}
1342 
1343 	/* Look for a Digest and a Basic challenge */
1344 	for (i = 0; i < cs->count; i++) {
1345 		if (cs->challenges[i]->scheme == HTTPAS_BASIC)
1346 			basic = cs->challenges[i];
1347 		if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1348 			digest = cs->challenges[i];
1349 	}
1350 
1351 	/* Error if "Digest" was specified and there is no Digest challenge */
1352 	if (!digest && (parms->scheme &&
1353 			!strcasecmp(parms->scheme, "digest"))) {
1354 		DEBUG(fprintf(stderr,
1355 			      "Digest auth in env, not supported by peer\n"));
1356 		return (-1);
1357 	}
1358 	/*
1359 	 * If "basic" was specified in the environment, or there is no Digest
1360 	 * challenge, do the basic thing. Don't need a challenge for this,
1361 	 * so no need to check basic!=NULL
1362 	 */
1363 	if (!digest || (parms->scheme && !strcasecmp(parms->scheme,"basic")))
1364 		return (http_basic_auth(conn,hdr,parms->user,parms->password));
1365 
1366 	/* Else, prefer digest. We just checked that it's not NULL */
1367 	return (http_digest_auth(conn, hdr, digest, parms, url));
1368 }
1369 
1370 /*****************************************************************************
1371  * Helper functions for connecting to a server or proxy
1372  */
1373 
1374 /*
1375  * Connect to the correct HTTP server or proxy.
1376  */
1377 static conn_t *
1378 http_connect(struct url *URL, struct url *purl, const char *flags)
1379 {
1380 	struct url *curl;
1381 	conn_t *conn;
1382 	int verbose;
1383 	int af, val;
1384 
1385 #ifdef INET6
1386 	af = AF_UNSPEC;
1387 #else
1388 	af = AF_INET;
1389 #endif
1390 
1391 	verbose = CHECK_FLAG('v');
1392 	if (CHECK_FLAG('4'))
1393 		af = AF_INET;
1394 #ifdef INET6
1395 	else if (CHECK_FLAG('6'))
1396 		af = AF_INET6;
1397 #endif
1398 
1399 	curl = (purl != NULL) ? purl : URL;
1400 
1401 	if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1402 		/* fetch_connect() has already set an error code */
1403 		return (NULL);
1404 	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1405 		http_cmd(conn, "CONNECT %s:%d HTTP/1.1",
1406 		    URL->host, URL->port);
1407 		http_cmd(conn, "Host: %s:%d",
1408 		    URL->host, URL->port);
1409 		http_cmd(conn, "");
1410 		if (http_get_reply(conn) != HTTP_OK) {
1411 			fetch_close(conn);
1412 			return (NULL);
1413 		}
1414 		http_get_reply(conn);
1415 	}
1416 	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1417 	    fetch_ssl(conn, URL, verbose) == -1) {
1418 		fetch_close(conn);
1419 		/* grrr */
1420 		errno = EAUTH;
1421 		fetch_syserr();
1422 		return (NULL);
1423 	}
1424 
1425 	val = 1;
1426 	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1427 
1428 	return (conn);
1429 }
1430 
1431 static struct url *
1432 http_get_proxy(struct url * url, const char *flags)
1433 {
1434 	struct url *purl;
1435 	char *p;
1436 
1437 	if (flags != NULL && strchr(flags, 'd') != NULL)
1438 		return (NULL);
1439 	if (fetch_no_proxy_match(url->host))
1440 		return (NULL);
1441 	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1442 	    *p && (purl = fetchParseURL(p))) {
1443 		if (!*purl->scheme)
1444 			strcpy(purl->scheme, SCHEME_HTTP);
1445 		if (!purl->port)
1446 			purl->port = fetch_default_proxy_port(purl->scheme);
1447 		if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1448 			return (purl);
1449 		fetchFreeURL(purl);
1450 	}
1451 	return (NULL);
1452 }
1453 
1454 static void
1455 http_print_html(FILE *out, FILE *in)
1456 {
1457 	size_t len;
1458 	char *line, *p, *q;
1459 	int comment, tag;
1460 
1461 	comment = tag = 0;
1462 	while ((line = fgetln(in, &len)) != NULL) {
1463 		while (len && isspace((unsigned char)line[len - 1]))
1464 			--len;
1465 		for (p = q = line; q < line + len; ++q) {
1466 			if (comment && *q == '-') {
1467 				if (q + 2 < line + len &&
1468 				    strcmp(q, "-->") == 0) {
1469 					tag = comment = 0;
1470 					q += 2;
1471 				}
1472 			} else if (tag && !comment && *q == '>') {
1473 				p = q + 1;
1474 				tag = 0;
1475 			} else if (!tag && *q == '<') {
1476 				if (q > p)
1477 					fwrite(p, q - p, 1, out);
1478 				tag = 1;
1479 				if (q + 3 < line + len &&
1480 				    strcmp(q, "<!--") == 0) {
1481 					comment = 1;
1482 					q += 3;
1483 				}
1484 			}
1485 		}
1486 		if (!tag && q > p)
1487 			fwrite(p, q - p, 1, out);
1488 		fputc('\n', out);
1489 	}
1490 }
1491 
1492 
1493 /*****************************************************************************
1494  * Core
1495  */
1496 
1497 FILE *
1498 http_request(struct url *URL, const char *op, struct url_stat *us,
1499 	struct url *purl, const char *flags)
1500 {
1501 
1502 	return (http_request_body(URL, op, us, purl, flags, NULL, NULL));
1503 }
1504 
1505 /*
1506  * Send a request and process the reply
1507  *
1508  * XXX This function is way too long, the do..while loop should be split
1509  * XXX off into a separate function.
1510  */
1511 FILE *
1512 http_request_body(struct url *URL, const char *op, struct url_stat *us,
1513 	struct url *purl, const char *flags, const char *content_type,
1514 	const char *body)
1515 {
1516 	char timebuf[80];
1517 	char hbuf[MAXHOSTNAMELEN + 7], *host;
1518 	conn_t *conn;
1519 	struct url *url, *new;
1520 	int chunked, direct, ims, noredirect, verbose;
1521 	int e, i, n, val;
1522 	off_t offset, clength, length, size;
1523 	time_t mtime;
1524 	const char *p;
1525 	FILE *f;
1526 	hdr_t h;
1527 	struct tm *timestruct;
1528 	http_headerbuf_t headerbuf;
1529 	http_auth_challenges_t server_challenges;
1530 	http_auth_challenges_t proxy_challenges;
1531 	size_t body_len;
1532 
1533 	/* The following calls don't allocate anything */
1534 	init_http_headerbuf(&headerbuf);
1535 	init_http_auth_challenges(&server_challenges);
1536 	init_http_auth_challenges(&proxy_challenges);
1537 
1538 	direct = CHECK_FLAG('d');
1539 	noredirect = CHECK_FLAG('A');
1540 	verbose = CHECK_FLAG('v');
1541 	ims = CHECK_FLAG('i');
1542 
1543 	if (direct && purl) {
1544 		fetchFreeURL(purl);
1545 		purl = NULL;
1546 	}
1547 
1548 	/* try the provided URL first */
1549 	url = URL;
1550 
1551 	n = MAX_REDIRECT;
1552 	i = 0;
1553 
1554 	e = HTTP_PROTOCOL_ERROR;
1555 	do {
1556 		new = NULL;
1557 		chunked = 0;
1558 		offset = 0;
1559 		clength = -1;
1560 		length = -1;
1561 		size = -1;
1562 		mtime = 0;
1563 
1564 		/* check port */
1565 		if (!url->port)
1566 			url->port = fetch_default_port(url->scheme);
1567 
1568 		/* were we redirected to an FTP URL? */
1569 		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1570 			if (strcmp(op, "GET") == 0)
1571 				return (ftp_request(url, "RETR", us, purl, flags));
1572 			else if (strcmp(op, "HEAD") == 0)
1573 				return (ftp_request(url, "STAT", us, purl, flags));
1574 		}
1575 
1576 		/* connect to server or proxy */
1577 		if ((conn = http_connect(url, purl, flags)) == NULL)
1578 			goto ouch;
1579 
1580 		host = url->host;
1581 #ifdef INET6
1582 		if (strchr(url->host, ':')) {
1583 			snprintf(hbuf, sizeof(hbuf), "[%s]", url->host);
1584 			host = hbuf;
1585 		}
1586 #endif
1587 		if (url->port != fetch_default_port(url->scheme)) {
1588 			if (host != hbuf) {
1589 				strcpy(hbuf, host);
1590 				host = hbuf;
1591 			}
1592 			snprintf(hbuf + strlen(hbuf),
1593 			    sizeof(hbuf) - strlen(hbuf), ":%d", url->port);
1594 		}
1595 
1596 		/* send request */
1597 		if (verbose)
1598 			fetch_info("requesting %s://%s%s",
1599 			    url->scheme, host, url->doc);
1600 		if (purl && strcasecmp(URL->scheme, SCHEME_HTTPS) != 0) {
1601 			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1602 			    op, url->scheme, host, url->doc);
1603 		} else {
1604 			http_cmd(conn, "%s %s HTTP/1.1",
1605 			    op, url->doc);
1606 		}
1607 
1608 		if (ims && url->ims_time) {
1609 			timestruct = gmtime((time_t *)&url->ims_time);
1610 			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1611 			    timestruct);
1612 			if (verbose)
1613 				fetch_info("If-Modified-Since: %s", timebuf);
1614 			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1615 		}
1616 		/* virtual host */
1617 		http_cmd(conn, "Host: %s", host);
1618 
1619 		/*
1620 		 * Proxy authorization: we only send auth after we received
1621 		 * a 407 error. We do not first try basic anyway (changed
1622 		 * when support was added for digest-auth)
1623 		 */
1624 		if (purl && proxy_challenges.valid) {
1625 			http_auth_params_t aparams;
1626 			init_http_auth_params(&aparams);
1627 			if (*purl->user || *purl->pwd) {
1628 				aparams.user = purl->user ?
1629 					strdup(purl->user) : strdup("");
1630 				aparams.password = purl->pwd?
1631 					strdup(purl->pwd) : strdup("");
1632 			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1633 				   *p != '\0') {
1634 				if (http_authfromenv(p, &aparams) < 0) {
1635 					http_seterr(HTTP_NEED_PROXY_AUTH);
1636 					goto ouch;
1637 				}
1638 			}
1639 			http_authorize(conn, "Proxy-Authorization",
1640 				       &proxy_challenges, &aparams, url);
1641 			clean_http_auth_params(&aparams);
1642 		}
1643 
1644 		/*
1645 		 * Server authorization: we never send "a priori"
1646 		 * Basic auth, which used to be done if user/pass were
1647 		 * set in the url. This would be weird because we'd send the
1648 		 * password in the clear even if Digest is finally to be
1649 		 * used (it would have made more sense for the
1650 		 * pre-digest version to do this when Basic was specified
1651 		 * in the environment)
1652 		 */
1653 		if (server_challenges.valid) {
1654 			http_auth_params_t aparams;
1655 			init_http_auth_params(&aparams);
1656 			if (*url->user || *url->pwd) {
1657 				aparams.user = url->user ?
1658 					strdup(url->user) : strdup("");
1659 				aparams.password = url->pwd ?
1660 					strdup(url->pwd) : strdup("");
1661 			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1662 				   *p != '\0') {
1663 				if (http_authfromenv(p, &aparams) < 0) {
1664 					http_seterr(HTTP_NEED_AUTH);
1665 					goto ouch;
1666 				}
1667 			} else if (fetchAuthMethod &&
1668 				   fetchAuthMethod(url) == 0) {
1669 				aparams.user = url->user ?
1670 					strdup(url->user) : strdup("");
1671 				aparams.password = url->pwd ?
1672 					strdup(url->pwd) : strdup("");
1673 			} else {
1674 				http_seterr(HTTP_NEED_AUTH);
1675 				goto ouch;
1676 			}
1677 			http_authorize(conn, "Authorization",
1678 				       &server_challenges, &aparams, url);
1679 			clean_http_auth_params(&aparams);
1680 		}
1681 
1682 		/* other headers */
1683 		if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1684 			if (*p != '\0')
1685 				http_cmd(conn, "Accept: %s", p);
1686 		} else {
1687 			http_cmd(conn, "Accept: */*");
1688 		}
1689 		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1690 			if (strcasecmp(p, "auto") == 0)
1691 				http_cmd(conn, "Referer: %s://%s%s",
1692 				    url->scheme, host, url->doc);
1693 			else
1694 				http_cmd(conn, "Referer: %s", p);
1695 		}
1696 		if ((p = getenv("HTTP_USER_AGENT")) != NULL) {
1697 			/* no User-Agent if defined but empty */
1698 			if  (*p != '\0')
1699 				http_cmd(conn, "User-Agent: %s", p);
1700 		} else {
1701 			/* default User-Agent */
1702 			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER,
1703 			    getprogname());
1704 		}
1705 		if (url->offset > 0)
1706 			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1707 		http_cmd(conn, "Connection: close");
1708 
1709 		if (body) {
1710 			body_len = strlen(body);
1711 			http_cmd(conn, "Content-Length: %zu", body_len);
1712 			if (content_type != NULL)
1713 				http_cmd(conn, "Content-Type: %s", content_type);
1714 		}
1715 
1716 		http_cmd(conn, "");
1717 
1718 		if (body)
1719 			fetch_write(conn, body, body_len);
1720 
1721 		/*
1722 		 * Force the queued request to be dispatched.  Normally, one
1723 		 * would do this with shutdown(2) but squid proxies can be
1724 		 * configured to disallow such half-closed connections.  To
1725 		 * be compatible with such configurations, fiddle with socket
1726 		 * options to force the pending data to be written.
1727 		 */
1728 		val = 0;
1729 		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1730 			   sizeof(val));
1731 		val = 1;
1732 		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1733 			   sizeof(val));
1734 
1735 		/* get reply */
1736 		switch (http_get_reply(conn)) {
1737 		case HTTP_OK:
1738 		case HTTP_PARTIAL:
1739 		case HTTP_NOT_MODIFIED:
1740 			/* fine */
1741 			break;
1742 		case HTTP_MOVED_PERM:
1743 		case HTTP_MOVED_TEMP:
1744 		case HTTP_SEE_OTHER:
1745 		case HTTP_USE_PROXY:
1746 			/*
1747 			 * Not so fine, but we still have to read the
1748 			 * headers to get the new location.
1749 			 */
1750 			break;
1751 		case HTTP_NEED_AUTH:
1752 			if (server_challenges.valid) {
1753 				/*
1754 				 * We already sent out authorization code,
1755 				 * so there's nothing more we can do.
1756 				 */
1757 				http_seterr(conn->err);
1758 				goto ouch;
1759 			}
1760 			/* try again, but send the password this time */
1761 			if (verbose)
1762 				fetch_info("server requires authorization");
1763 			break;
1764 		case HTTP_NEED_PROXY_AUTH:
1765 			if (proxy_challenges.valid) {
1766 				/*
1767 				 * We already sent our proxy
1768 				 * authorization code, so there's
1769 				 * nothing more we can do. */
1770 				http_seterr(conn->err);
1771 				goto ouch;
1772 			}
1773 			/* try again, but send the password this time */
1774 			if (verbose)
1775 				fetch_info("proxy requires authorization");
1776 			break;
1777 		case HTTP_BAD_RANGE:
1778 			/*
1779 			 * This can happen if we ask for 0 bytes because
1780 			 * we already have the whole file.  Consider this
1781 			 * a success for now, and check sizes later.
1782 			 */
1783 			break;
1784 		case HTTP_PROTOCOL_ERROR:
1785 			/* fall through */
1786 		case -1:
1787 			fetch_syserr();
1788 			goto ouch;
1789 		default:
1790 			http_seterr(conn->err);
1791 			if (!verbose)
1792 				goto ouch;
1793 			/* fall through so we can get the full error message */
1794 		}
1795 
1796 		/* get headers. http_next_header expects one line readahead */
1797 		if (fetch_getln(conn) == -1) {
1798 			fetch_syserr();
1799 			goto ouch;
1800 		}
1801 		do {
1802 			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1803 			case hdr_syserror:
1804 				fetch_syserr();
1805 				goto ouch;
1806 			case hdr_error:
1807 				http_seterr(HTTP_PROTOCOL_ERROR);
1808 				goto ouch;
1809 			case hdr_content_length:
1810 				http_parse_length(p, &clength);
1811 				break;
1812 			case hdr_content_range:
1813 				http_parse_range(p, &offset, &length, &size);
1814 				break;
1815 			case hdr_last_modified:
1816 				http_parse_mtime(p, &mtime);
1817 				break;
1818 			case hdr_location:
1819 				if (!HTTP_REDIRECT(conn->err))
1820 					break;
1821 				/*
1822 				 * if the A flag is set, we don't follow
1823 				 * temporary redirects.
1824 				 */
1825 				if (noredirect &&
1826 				    conn->err != HTTP_MOVED_PERM &&
1827 				    conn->err != HTTP_PERM_REDIRECT &&
1828 				    conn->err != HTTP_USE_PROXY) {
1829 					n = 1;
1830 					break;
1831 				}
1832 				if (new)
1833 					free(new);
1834 				if (verbose)
1835 					fetch_info("%d redirect to %s", conn->err, p);
1836 				if (*p == '/')
1837 					/* absolute path */
1838 					new = fetchMakeURL(url->scheme, url->host, url->port, p,
1839 					    url->user, url->pwd);
1840 				else
1841 					new = fetchParseURL(p);
1842 				if (new == NULL) {
1843 					/* XXX should set an error code */
1844 					DEBUG(fprintf(stderr, "failed to parse new URL\n"));
1845 					goto ouch;
1846 				}
1847 
1848 				/* Only copy credentials if the host matches */
1849 				if (!strcmp(new->host, url->host) && !*new->user && !*new->pwd) {
1850 					strcpy(new->user, url->user);
1851 					strcpy(new->pwd, url->pwd);
1852 				}
1853 				new->offset = url->offset;
1854 				new->length = url->length;
1855 				break;
1856 			case hdr_transfer_encoding:
1857 				/* XXX weak test*/
1858 				chunked = (strcasecmp(p, "chunked") == 0);
1859 				break;
1860 			case hdr_www_authenticate:
1861 				if (conn->err != HTTP_NEED_AUTH)
1862 					break;
1863 				if (http_parse_authenticate(p, &server_challenges) == 0)
1864 					++n;
1865 				break;
1866 			case hdr_proxy_authenticate:
1867 				if (conn->err != HTTP_NEED_PROXY_AUTH)
1868 					break;
1869 				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1870 					++n;
1871 				break;
1872 			case hdr_end:
1873 				/* fall through */
1874 			case hdr_unknown:
1875 				/* ignore */
1876 				break;
1877 			}
1878 		} while (h > hdr_end);
1879 
1880 		/* we need to provide authentication */
1881 		if (conn->err == HTTP_NEED_AUTH ||
1882 		    conn->err == HTTP_NEED_PROXY_AUTH) {
1883 			e = conn->err;
1884 			if ((conn->err == HTTP_NEED_AUTH &&
1885 			     !server_challenges.valid) ||
1886 			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1887 			     !proxy_challenges.valid)) {
1888 				/* 401/7 but no www/proxy-authenticate ?? */
1889 				DEBUG(fprintf(stderr, "401/7 and no auth header\n"));
1890 				goto ouch;
1891 			}
1892 			fetch_close(conn);
1893 			conn = NULL;
1894 			continue;
1895 		}
1896 
1897 		/* requested range not satisfiable */
1898 		if (conn->err == HTTP_BAD_RANGE) {
1899 			if (url->offset == size && url->length == 0) {
1900 				/* asked for 0 bytes; fake it */
1901 				offset = url->offset;
1902 				clength = -1;
1903 				conn->err = HTTP_OK;
1904 				break;
1905 			} else {
1906 				http_seterr(conn->err);
1907 				goto ouch;
1908 			}
1909 		}
1910 
1911 		/* we have a hit or an error */
1912 		if (conn->err == HTTP_OK
1913 		    || conn->err == HTTP_NOT_MODIFIED
1914 		    || conn->err == HTTP_PARTIAL
1915 		    || HTTP_ERROR(conn->err))
1916 			break;
1917 
1918 		/* all other cases: we got a redirect */
1919 		e = conn->err;
1920 		clean_http_auth_challenges(&server_challenges);
1921 		fetch_close(conn);
1922 		conn = NULL;
1923 		if (!new) {
1924 			DEBUG(fprintf(stderr, "redirect with no new location\n"));
1925 			break;
1926 		}
1927 		if (url != URL)
1928 			fetchFreeURL(url);
1929 		url = new;
1930 	} while (++i < n);
1931 
1932 	/* we failed, or ran out of retries */
1933 	if (conn == NULL) {
1934 		http_seterr(e);
1935 		goto ouch;
1936 	}
1937 
1938 	DEBUG(fprintf(stderr, "offset %lld, length %lld,"
1939 		  " size %lld, clength %lld\n",
1940 		  (long long)offset, (long long)length,
1941 		  (long long)size, (long long)clength));
1942 
1943 	if (conn->err == HTTP_NOT_MODIFIED) {
1944 		http_seterr(HTTP_NOT_MODIFIED);
1945 		return (NULL);
1946 	}
1947 
1948 	/* check for inconsistencies */
1949 	if (clength != -1 && length != -1 && clength != length) {
1950 		http_seterr(HTTP_PROTOCOL_ERROR);
1951 		goto ouch;
1952 	}
1953 	if (clength == -1)
1954 		clength = length;
1955 	if (clength != -1)
1956 		length = offset + clength;
1957 	if (length != -1 && size != -1 && length != size) {
1958 		http_seterr(HTTP_PROTOCOL_ERROR);
1959 		goto ouch;
1960 	}
1961 	if (size == -1)
1962 		size = length;
1963 
1964 	/* fill in stats */
1965 	if (us) {
1966 		us->size = size;
1967 		us->atime = us->mtime = mtime;
1968 	}
1969 
1970 	/* too far? */
1971 	if (URL->offset > 0 && offset > URL->offset) {
1972 		http_seterr(HTTP_PROTOCOL_ERROR);
1973 		goto ouch;
1974 	}
1975 
1976 	/* report back real offset and size */
1977 	URL->offset = offset;
1978 	URL->length = clength;
1979 
1980 	/* wrap it up in a FILE */
1981 	if ((f = http_funopen(conn, chunked)) == NULL) {
1982 		fetch_syserr();
1983 		goto ouch;
1984 	}
1985 
1986 	if (url != URL)
1987 		fetchFreeURL(url);
1988 	if (purl)
1989 		fetchFreeURL(purl);
1990 
1991 	if (HTTP_ERROR(conn->err)) {
1992 		http_print_html(stderr, f);
1993 		fclose(f);
1994 		f = NULL;
1995 	}
1996 	clean_http_headerbuf(&headerbuf);
1997 	clean_http_auth_challenges(&server_challenges);
1998 	clean_http_auth_challenges(&proxy_challenges);
1999 	return (f);
2000 
2001 ouch:
2002 	if (url != URL)
2003 		fetchFreeURL(url);
2004 	if (purl)
2005 		fetchFreeURL(purl);
2006 	if (conn != NULL)
2007 		fetch_close(conn);
2008 	clean_http_headerbuf(&headerbuf);
2009 	clean_http_auth_challenges(&server_challenges);
2010 	clean_http_auth_challenges(&proxy_challenges);
2011 	return (NULL);
2012 }
2013 
2014 
2015 /*****************************************************************************
2016  * Entry points
2017  */
2018 
2019 /*
2020  * Retrieve and stat a file by HTTP
2021  */
2022 FILE *
2023 fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
2024 {
2025 	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
2026 }
2027 
2028 /*
2029  * Retrieve a file by HTTP
2030  */
2031 FILE *
2032 fetchGetHTTP(struct url *URL, const char *flags)
2033 {
2034 	return (fetchXGetHTTP(URL, NULL, flags));
2035 }
2036 
2037 /*
2038  * Store a file by HTTP
2039  */
2040 FILE *
2041 fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2042 {
2043 	warnx("fetchPutHTTP(): not implemented");
2044 	return (NULL);
2045 }
2046 
2047 /*
2048  * Get an HTTP document's metadata
2049  */
2050 int
2051 fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2052 {
2053 	FILE *f;
2054 
2055 	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2056 	if (f == NULL)
2057 		return (-1);
2058 	fclose(f);
2059 	return (0);
2060 }
2061 
2062 /*
2063  * List a directory
2064  */
2065 struct url_ent *
2066 fetchListHTTP(struct url *url __unused, const char *flags __unused)
2067 {
2068 	warnx("fetchListHTTP(): not implemented");
2069 	return (NULL);
2070 }
2071 
2072 FILE *
2073 fetchReqHTTP(struct url *URL, const char *method, const char *flags,
2074 	const char *content_type, const char *body)
2075 {
2076 
2077 	return (http_request_body(URL, method, NULL, http_get_proxy(URL, flags),
2078 	    flags, content_type, body));
2079 }
2080