xref: /freebsd/lib/libfetch/http.c (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
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 	size_t		 buflen;	/* amount of data currently in buffer */
134 	size_t		 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 	/* not chunked: just fetch the requested amount */
219 	if (io->chunked == 0) {
220 		if (http_growbuf(io, len) == -1)
221 			return (-1);
222 		if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
223 			io->error = errno;
224 			return (-1);
225 		}
226 		io->buflen = nbytes;
227 		io->bufpos = 0;
228 		return (io->buflen);
229 	}
230 
231 	/* chunked, but we ran out: get the next chunk header */
232 	if (io->chunksize == 0) {
233 		switch (http_new_chunk(io)) {
234 		case -1:
235 			io->error = EPROTO;
236 			return (-1);
237 		case 0:
238 			io->eof = 1;
239 			return (0);
240 		}
241 	}
242 
243 	/* fetch the requested amount, but no more than the current chunk */
244 	if (len > io->chunksize)
245 		len = io->chunksize;
246 	if (http_growbuf(io, len) == -1)
247 		return (-1);
248 	if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
249 		io->error = errno;
250 		return (-1);
251 	}
252 	io->bufpos = 0;
253 	io->buflen = nbytes;
254 	io->chunksize -= nbytes;
255 
256 	if (io->chunksize == 0) {
257 		if (fetch_read(io->conn, &ch, 1) != 1 || ch != '\r' ||
258 		    fetch_read(io->conn, &ch, 1) != 1 || ch != '\n')
259 			return (-1);
260 	}
261 
262 	return (io->buflen);
263 }
264 
265 /*
266  * Read function
267  */
268 static int
269 http_readfn(void *v, char *buf, int len)
270 {
271 	struct httpio *io = (struct httpio *)v;
272 	int rlen;
273 
274 	if (io->error)
275 		return (-1);
276 	if (io->eof)
277 		return (0);
278 
279 	/* empty buffer */
280 	if (!io->buf || io->bufpos == io->buflen) {
281 		if ((rlen = http_fillbuf(io, len)) < 0) {
282 			if ((errno = io->error) == EINTR)
283 				io->error = 0;
284 			return (-1);
285 		} else if (rlen == 0) {
286 			return (0);
287 		}
288 	}
289 
290 	rlen = io->buflen - io->bufpos;
291 	if (len < rlen)
292 		rlen = len;
293 	memcpy(buf, io->buf + io->bufpos, rlen);
294 	io->bufpos += rlen;
295 	return (rlen);
296 }
297 
298 /*
299  * Write function
300  */
301 static int
302 http_writefn(void *v, const char *buf, int len)
303 {
304 	struct httpio *io = (struct httpio *)v;
305 
306 	return (fetch_write(io->conn, buf, len));
307 }
308 
309 /*
310  * Close function
311  */
312 static int
313 http_closefn(void *v)
314 {
315 	struct httpio *io = (struct httpio *)v;
316 	int r;
317 
318 	r = fetch_close(io->conn);
319 	if (io->buf)
320 		free(io->buf);
321 	free(io);
322 	return (r);
323 }
324 
325 /*
326  * Wrap a file descriptor up
327  */
328 static FILE *
329 http_funopen(conn_t *conn, int chunked)
330 {
331 	struct httpio *io;
332 	FILE *f;
333 
334 	if ((io = calloc(1, sizeof(*io))) == NULL) {
335 		fetch_syserr();
336 		return (NULL);
337 	}
338 	io->conn = conn;
339 	io->chunked = chunked;
340 	f = funopen(io, http_readfn, http_writefn, NULL, http_closefn);
341 	if (f == NULL) {
342 		fetch_syserr();
343 		free(io);
344 		return (NULL);
345 	}
346 	return (f);
347 }
348 
349 
350 /*****************************************************************************
351  * Helper functions for talking to the server and parsing its replies
352  */
353 
354 /* Header types */
355 typedef enum {
356 	hdr_syserror = -2,
357 	hdr_error = -1,
358 	hdr_end = 0,
359 	hdr_unknown = 1,
360 	hdr_content_length,
361 	hdr_content_range,
362 	hdr_last_modified,
363 	hdr_location,
364 	hdr_transfer_encoding,
365 	hdr_www_authenticate,
366 	hdr_proxy_authenticate,
367 } hdr_t;
368 
369 /* Names of interesting headers */
370 static struct {
371 	hdr_t		 num;
372 	const char	*name;
373 } hdr_names[] = {
374 	{ hdr_content_length,		"Content-Length" },
375 	{ hdr_content_range,		"Content-Range" },
376 	{ hdr_last_modified,		"Last-Modified" },
377 	{ hdr_location,			"Location" },
378 	{ hdr_transfer_encoding,	"Transfer-Encoding" },
379 	{ hdr_www_authenticate,		"WWW-Authenticate" },
380 	{ hdr_proxy_authenticate,	"Proxy-Authenticate" },
381 	{ hdr_unknown,			NULL },
382 };
383 
384 /*
385  * Send a formatted line; optionally echo to terminal
386  */
387 static int
388 http_cmd(conn_t *conn, const char *fmt, ...)
389 {
390 	va_list ap;
391 	size_t len;
392 	char *msg;
393 	int r;
394 
395 	va_start(ap, fmt);
396 	len = vasprintf(&msg, fmt, ap);
397 	va_end(ap);
398 
399 	if (msg == NULL) {
400 		errno = ENOMEM;
401 		fetch_syserr();
402 		return (-1);
403 	}
404 
405 	r = fetch_putln(conn, msg, len);
406 	free(msg);
407 
408 	if (r == -1) {
409 		fetch_syserr();
410 		return (-1);
411 	}
412 
413 	return (0);
414 }
415 
416 /*
417  * Get and parse status line
418  */
419 static int
420 http_get_reply(conn_t *conn)
421 {
422 	char *p;
423 
424 	if (fetch_getln(conn) == -1)
425 		return (-1);
426 	/*
427 	 * A valid status line looks like "HTTP/m.n xyz reason" where m
428 	 * and n are the major and minor protocol version numbers and xyz
429 	 * is the reply code.
430 	 * Unfortunately, there are servers out there (NCSA 1.5.1, to name
431 	 * just one) that do not send a version number, so we can't rely
432 	 * on finding one, but if we do, insist on it being 1.0 or 1.1.
433 	 * We don't care about the reason phrase.
434 	 */
435 	if (strncmp(conn->buf, "HTTP", 4) != 0)
436 		return (HTTP_PROTOCOL_ERROR);
437 	p = conn->buf + 4;
438 	if (*p == '/') {
439 		if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
440 			return (HTTP_PROTOCOL_ERROR);
441 		p += 4;
442 	}
443 	if (*p != ' ' ||
444 	    !isdigit((unsigned char)p[1]) ||
445 	    !isdigit((unsigned char)p[2]) ||
446 	    !isdigit((unsigned char)p[3]))
447 		return (HTTP_PROTOCOL_ERROR);
448 
449 	conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
450 	return (conn->err);
451 }
452 
453 /*
454  * Check a header; if the type matches the given string, return a pointer
455  * to the beginning of the value.
456  */
457 static const char *
458 http_match(const char *str, const char *hdr)
459 {
460 	while (*str && *hdr &&
461 	    tolower((unsigned char)*str++) == tolower((unsigned char)*hdr++))
462 		/* nothing */;
463 	if (*str || *hdr != ':')
464 		return (NULL);
465 	while (*hdr && isspace((unsigned char)*++hdr))
466 		/* nothing */;
467 	return (hdr);
468 }
469 
470 
471 /*
472  * Get the next header and return the appropriate symbolic code.  We
473  * need to read one line ahead for checking for a continuation line
474  * belonging to the current header (continuation lines start with
475  * white space).
476  *
477  * We get called with a fresh line already in the conn buffer, either
478  * from the previous http_next_header() invocation, or, the first
479  * time, from a fetch_getln() performed by our caller.
480  *
481  * This stops when we encounter an empty line (we dont read beyond the header
482  * area).
483  *
484  * Note that the "headerbuf" is just a place to return the result. Its
485  * contents are not used for the next call. This means that no cleanup
486  * is needed when ie doing another connection, just call the cleanup when
487  * fully done to deallocate memory.
488  */
489 
490 /* Limit the max number of continuation lines to some reasonable value */
491 #define HTTP_MAX_CONT_LINES 10
492 
493 /* Place into which to build a header from one or several lines */
494 typedef struct {
495 	char	*buf;		/* buffer */
496 	size_t	 bufsize;	/* buffer size */
497 	size_t	 buflen;	/* length of buffer contents */
498 } http_headerbuf_t;
499 
500 static void
501 init_http_headerbuf(http_headerbuf_t *buf)
502 {
503 	buf->buf = NULL;
504 	buf->bufsize = 0;
505 	buf->buflen = 0;
506 }
507 
508 static void
509 clean_http_headerbuf(http_headerbuf_t *buf)
510 {
511 	if (buf->buf)
512 		free(buf->buf);
513 	init_http_headerbuf(buf);
514 }
515 
516 /* Remove whitespace at the end of the buffer */
517 static void
518 http_conn_trimright(conn_t *conn)
519 {
520 	while (conn->buflen &&
521 	       isspace((unsigned char)conn->buf[conn->buflen - 1]))
522 		conn->buflen--;
523 	conn->buf[conn->buflen] = '\0';
524 }
525 
526 static hdr_t
527 http_next_header(conn_t *conn, http_headerbuf_t *hbuf, const char **p)
528 {
529 	unsigned int i, len;
530 
531 	/*
532 	 * Have to do the stripping here because of the first line. So
533 	 * it's done twice for the subsequent lines. No big deal
534 	 */
535 	http_conn_trimright(conn);
536 	if (conn->buflen == 0)
537 		return (hdr_end);
538 
539 	/* Copy the line to the headerbuf */
540 	if (hbuf->bufsize < conn->buflen + 1) {
541 		if ((hbuf->buf = realloc(hbuf->buf, conn->buflen + 1)) == NULL)
542 			return (hdr_syserror);
543 		hbuf->bufsize = conn->buflen + 1;
544 	}
545 	strcpy(hbuf->buf, conn->buf);
546 	hbuf->buflen = conn->buflen;
547 
548 	/*
549 	 * Fetch possible continuation lines. Stop at 1st non-continuation
550 	 * and leave it in the conn buffer
551 	 */
552 	for (i = 0; i < HTTP_MAX_CONT_LINES; i++) {
553 		if (fetch_getln(conn) == -1)
554 			return (hdr_syserror);
555 
556 		/*
557 		 * Note: we carry on the idea from the previous version
558 		 * that a pure whitespace line is equivalent to an empty
559 		 * one (so it's not continuation and will be handled when
560 		 * we are called next)
561 		 */
562 		http_conn_trimright(conn);
563 		if (conn->buf[0] != ' ' && conn->buf[0] != "\t"[0])
564 			break;
565 
566 		/* Got a continuation line. Concatenate to previous */
567 		len = hbuf->buflen + conn->buflen;
568 		if (hbuf->bufsize < len + 1) {
569 			len *= 2;
570 			if ((hbuf->buf = realloc(hbuf->buf, len + 1)) == NULL)
571 				return (hdr_syserror);
572 			hbuf->bufsize = len + 1;
573 		}
574 		strcpy(hbuf->buf + hbuf->buflen, conn->buf);
575 		hbuf->buflen += conn->buflen;
576 	}
577 
578 	/*
579 	 * We could check for malformed headers but we don't really care.
580 	 * A valid header starts with a token immediately followed by a
581 	 * colon; a token is any sequence of non-control, non-whitespace
582 	 * characters except "()<>@,;:\\\"{}".
583 	 */
584 	for (i = 0; hdr_names[i].num != hdr_unknown; i++)
585 		if ((*p = http_match(hdr_names[i].name, hbuf->buf)) != NULL)
586 			return (hdr_names[i].num);
587 
588 	return (hdr_unknown);
589 }
590 
591 /**************************
592  * [Proxy-]Authenticate header parsing
593  */
594 
595 /*
596  * Read doublequote-delimited string into output buffer obuf (allocated
597  * by caller, whose responsibility it is to ensure that it's big enough)
598  * cp points to the first char after the initial '"'
599  * Handles \ quoting
600  * Returns pointer to the first char after the terminating double quote, or
601  * NULL for error.
602  */
603 static const char *
604 http_parse_headerstring(const char *cp, char *obuf)
605 {
606 	for (;;) {
607 		switch (*cp) {
608 		case 0: /* Unterminated string */
609 			*obuf = 0;
610 			return (NULL);
611 		case '"': /* Ending quote */
612 			*obuf = 0;
613 			return (++cp);
614 		case '\\':
615 			if (*++cp == 0) {
616 				*obuf = 0;
617 				return (NULL);
618 			}
619 			/* FALLTHROUGH */
620 		default:
621 			*obuf++ = *cp++;
622 		}
623 	}
624 }
625 
626 /* Http auth challenge schemes */
627 typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
628 
629 /* Data holder for a Basic or Digest challenge. */
630 typedef struct {
631 	http_auth_schemes_t scheme;
632 	char	*realm;
633 	char	*qop;
634 	char	*nonce;
635 	char	*opaque;
636 	char	*algo;
637 	int	 stale;
638 	int	 nc; /* Nonce count */
639 } http_auth_challenge_t;
640 
641 static void
642 init_http_auth_challenge(http_auth_challenge_t *b)
643 {
644 	b->scheme = HTTPAS_UNKNOWN;
645 	b->realm = b->qop = b->nonce = b->opaque = b->algo = NULL;
646 	b->stale = b->nc = 0;
647 }
648 
649 static void
650 clean_http_auth_challenge(http_auth_challenge_t *b)
651 {
652 	if (b->realm)
653 		free(b->realm);
654 	if (b->qop)
655 		free(b->qop);
656 	if (b->nonce)
657 		free(b->nonce);
658 	if (b->opaque)
659 		free(b->opaque);
660 	if (b->algo)
661 		free(b->algo);
662 	init_http_auth_challenge(b);
663 }
664 
665 /* Data holder for an array of challenges offered in an http response. */
666 #define MAX_CHALLENGES 10
667 typedef struct {
668 	http_auth_challenge_t *challenges[MAX_CHALLENGES];
669 	int	count; /* Number of parsed challenges in the array */
670 	int	valid; /* We did parse an authenticate header */
671 } http_auth_challenges_t;
672 
673 static void
674 init_http_auth_challenges(http_auth_challenges_t *cs)
675 {
676 	int i;
677 	for (i = 0; i < MAX_CHALLENGES; i++)
678 		cs->challenges[i] = NULL;
679 	cs->count = cs->valid = 0;
680 }
681 
682 static void
683 clean_http_auth_challenges(http_auth_challenges_t *cs)
684 {
685 	int i;
686 	/* We rely on non-zero pointers being allocated, not on the count */
687 	for (i = 0; i < MAX_CHALLENGES; i++) {
688 		if (cs->challenges[i] != NULL) {
689 			clean_http_auth_challenge(cs->challenges[i]);
690 			free(cs->challenges[i]);
691 		}
692 	}
693 	init_http_auth_challenges(cs);
694 }
695 
696 /*
697  * Enumeration for lexical elements. Separators will be returned as their own
698  * ascii value
699  */
700 typedef enum {HTTPHL_WORD=256, HTTPHL_STRING=257, HTTPHL_END=258,
701 	      HTTPHL_ERROR = 259} http_header_lex_t;
702 
703 /*
704  * Determine what kind of token comes next and return possible value
705  * in buf, which is supposed to have been allocated big enough by
706  * caller. Advance input pointer and return element type.
707  */
708 static int
709 http_header_lex(const char **cpp, char *buf)
710 {
711 	size_t l;
712 	/* Eat initial whitespace */
713 	*cpp += strspn(*cpp, " \t");
714 	if (**cpp == 0)
715 		return (HTTPHL_END);
716 
717 	/* Separator ? */
718 	if (**cpp == ',' || **cpp == '=')
719 		return (*((*cpp)++));
720 
721 	/* String ? */
722 	if (**cpp == '"') {
723 		*cpp = http_parse_headerstring(++*cpp, buf);
724 		if (*cpp == NULL)
725 			return (HTTPHL_ERROR);
726 		return (HTTPHL_STRING);
727 	}
728 
729 	/* Read other token, until separator or whitespace */
730 	l = strcspn(*cpp, " \t,=");
731 	memcpy(buf, *cpp, l);
732 	buf[l] = 0;
733 	*cpp += l;
734 	return (HTTPHL_WORD);
735 }
736 
737 /*
738  * Read challenges from http xxx-authenticate header and accumulate them
739  * in the challenges list structure.
740  *
741  * Headers with multiple challenges are specified by rfc2617, but
742  * servers (ie: squid) often send them in separate headers instead,
743  * which in turn is forbidden by the http spec (multiple headers with
744  * the same name are only allowed for pure comma-separated lists, see
745  * rfc2616 sec 4.2).
746  *
747  * We support both approaches anyway
748  */
749 static int
750 http_parse_authenticate(const char *cp, http_auth_challenges_t *cs)
751 {
752 	int ret = -1;
753 	http_header_lex_t lex;
754 	char *key = malloc(strlen(cp) + 1);
755 	char *value = malloc(strlen(cp) + 1);
756 	char *buf = malloc(strlen(cp) + 1);
757 
758 	if (key == NULL || value == NULL || buf == NULL) {
759 		fetch_syserr();
760 		goto out;
761 	}
762 
763 	/* In any case we've seen the header and we set the valid bit */
764 	cs->valid = 1;
765 
766 	/* Need word first */
767 	lex = http_header_lex(&cp, key);
768 	if (lex != HTTPHL_WORD)
769 		goto out;
770 
771 	/* Loop on challenges */
772 	for (; cs->count < MAX_CHALLENGES; cs->count++) {
773 		cs->challenges[cs->count] =
774 			malloc(sizeof(http_auth_challenge_t));
775 		if (cs->challenges[cs->count] == NULL) {
776 			fetch_syserr();
777 			goto out;
778 		}
779 		init_http_auth_challenge(cs->challenges[cs->count]);
780 		if (!strcasecmp(key, "basic")) {
781 			cs->challenges[cs->count]->scheme = HTTPAS_BASIC;
782 		} else if (!strcasecmp(key, "digest")) {
783 			cs->challenges[cs->count]->scheme = HTTPAS_DIGEST;
784 		} else {
785 			cs->challenges[cs->count]->scheme = HTTPAS_UNKNOWN;
786 			/*
787 			 * Continue parsing as basic or digest may
788 			 * follow, and the syntax is the same for
789 			 * all. We'll just ignore this one when
790 			 * looking at the list
791 			 */
792 		}
793 
794 		/* Loop on attributes */
795 		for (;;) {
796 			/* Key */
797 			lex = http_header_lex(&cp, key);
798 			if (lex != HTTPHL_WORD)
799 				goto out;
800 
801 			/* Equal sign */
802 			lex = http_header_lex(&cp, buf);
803 			if (lex != '=')
804 				goto out;
805 
806 			/* Value */
807 			lex = http_header_lex(&cp, value);
808 			if (lex != HTTPHL_WORD && lex != HTTPHL_STRING)
809 				goto out;
810 
811 			if (!strcasecmp(key, "realm"))
812 				cs->challenges[cs->count]->realm =
813 					strdup(value);
814 			else if (!strcasecmp(key, "qop"))
815 				cs->challenges[cs->count]->qop =
816 					strdup(value);
817 			else if (!strcasecmp(key, "nonce"))
818 				cs->challenges[cs->count]->nonce =
819 					strdup(value);
820 			else if (!strcasecmp(key, "opaque"))
821 				cs->challenges[cs->count]->opaque =
822 					strdup(value);
823 			else if (!strcasecmp(key, "algorithm"))
824 				cs->challenges[cs->count]->algo =
825 					strdup(value);
826 			else if (!strcasecmp(key, "stale"))
827 				cs->challenges[cs->count]->stale =
828 					strcasecmp(value, "no");
829 			/* Else ignore unknown attributes */
830 
831 			/* Comma or Next challenge or End */
832 			lex = http_header_lex(&cp, key);
833 			/*
834 			 * If we get a word here, this is the beginning of the
835 			 * next challenge. Break the attributes loop
836 			 */
837 			if (lex == HTTPHL_WORD)
838 				break;
839 
840 			if (lex == HTTPHL_END) {
841 				/* End while looking for ',' is normal exit */
842 				cs->count++;
843 				ret = 0;
844 				goto out;
845 			}
846 			/* Anything else is an error */
847 			if (lex != ',')
848 				goto out;
849 
850 		} /* End attributes loop */
851 	} /* End challenge loop */
852 
853 	/*
854 	 * Challenges max count exceeded. This really can't happen
855 	 * with normal data, something's fishy -> error
856 	 */
857 
858 out:
859 	if (key)
860 		free(key);
861 	if (value)
862 		free(value);
863 	if (buf)
864 		free(buf);
865 	return (ret);
866 }
867 
868 
869 /*
870  * Parse a last-modified header
871  */
872 static int
873 http_parse_mtime(const char *p, time_t *mtime)
874 {
875 	char locale[64], *r;
876 	struct tm tm;
877 
878 	strncpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
879 	setlocale(LC_TIME, "C");
880 	r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
881 	/*
882 	 * Some proxies use UTC in response, but it should still be
883 	 * parsed. RFC2616 states GMT and UTC are exactly equal for HTTP.
884 	 */
885 	if (r == NULL)
886 		r = strptime(p, "%a, %d %b %Y %H:%M:%S UTC", &tm);
887 	/* XXX should add support for date-2 and date-3 */
888 	setlocale(LC_TIME, locale);
889 	if (r == NULL)
890 		return (-1);
891 	DEBUG(fprintf(stderr, "last modified: [%04d-%02d-%02d "
892 		  "%02d:%02d:%02d]\n",
893 		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
894 		  tm.tm_hour, tm.tm_min, tm.tm_sec));
895 	*mtime = timegm(&tm);
896 	return (0);
897 }
898 
899 /*
900  * Parse a content-length header
901  */
902 static int
903 http_parse_length(const char *p, off_t *length)
904 {
905 	off_t len;
906 
907 	for (len = 0; *p && isdigit((unsigned char)*p); ++p)
908 		len = len * 10 + (*p - '0');
909 	if (*p)
910 		return (-1);
911 	DEBUG(fprintf(stderr, "content length: [%lld]\n",
912 	    (long long)len));
913 	*length = len;
914 	return (0);
915 }
916 
917 /*
918  * Parse a content-range header
919  */
920 static int
921 http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
922 {
923 	off_t first, last, len;
924 
925 	if (strncasecmp(p, "bytes ", 6) != 0)
926 		return (-1);
927 	p += 6;
928 	if (*p == '*') {
929 		first = last = -1;
930 		++p;
931 	} else {
932 		for (first = 0; *p && isdigit((unsigned char)*p); ++p)
933 			first = first * 10 + *p - '0';
934 		if (*p != '-')
935 			return (-1);
936 		for (last = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
937 			last = last * 10 + *p - '0';
938 	}
939 	if (first > last || *p != '/')
940 		return (-1);
941 	for (len = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
942 		len = len * 10 + *p - '0';
943 	if (*p || len < last - first + 1)
944 		return (-1);
945 	if (first == -1) {
946 		DEBUG(fprintf(stderr, "content range: [*/%lld]\n",
947 		    (long long)len));
948 		*length = 0;
949 	} else {
950 		DEBUG(fprintf(stderr, "content range: [%lld-%lld/%lld]\n",
951 		    (long long)first, (long long)last, (long long)len));
952 		*length = last - first + 1;
953 	}
954 	*offset = first;
955 	*size = len;
956 	return (0);
957 }
958 
959 
960 /*****************************************************************************
961  * Helper functions for authorization
962  */
963 
964 /*
965  * Base64 encoding
966  */
967 static char *
968 http_base64(const char *src)
969 {
970 	static const char base64[] =
971 	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
972 	    "abcdefghijklmnopqrstuvwxyz"
973 	    "0123456789+/";
974 	char *str, *dst;
975 	size_t l;
976 	int t, r;
977 
978 	l = strlen(src);
979 	if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
980 		return (NULL);
981 	dst = str;
982 	r = 0;
983 
984 	while (l >= 3) {
985 		t = (src[0] << 16) | (src[1] << 8) | src[2];
986 		dst[0] = base64[(t >> 18) & 0x3f];
987 		dst[1] = base64[(t >> 12) & 0x3f];
988 		dst[2] = base64[(t >> 6) & 0x3f];
989 		dst[3] = base64[(t >> 0) & 0x3f];
990 		src += 3; l -= 3;
991 		dst += 4; r += 4;
992 	}
993 
994 	switch (l) {
995 	case 2:
996 		t = (src[0] << 16) | (src[1] << 8);
997 		dst[0] = base64[(t >> 18) & 0x3f];
998 		dst[1] = base64[(t >> 12) & 0x3f];
999 		dst[2] = base64[(t >> 6) & 0x3f];
1000 		dst[3] = '=';
1001 		dst += 4;
1002 		r += 4;
1003 		break;
1004 	case 1:
1005 		t = src[0] << 16;
1006 		dst[0] = base64[(t >> 18) & 0x3f];
1007 		dst[1] = base64[(t >> 12) & 0x3f];
1008 		dst[2] = dst[3] = '=';
1009 		dst += 4;
1010 		r += 4;
1011 		break;
1012 	case 0:
1013 		break;
1014 	}
1015 
1016 	*dst = 0;
1017 	return (str);
1018 }
1019 
1020 
1021 /*
1022  * Extract authorization parameters from environment value.
1023  * The value is like scheme:realm:user:pass
1024  */
1025 typedef struct {
1026 	char	*scheme;
1027 	char	*realm;
1028 	char	*user;
1029 	char	*password;
1030 } http_auth_params_t;
1031 
1032 static void
1033 init_http_auth_params(http_auth_params_t *s)
1034 {
1035 	s->scheme = s->realm = s->user = s->password = NULL;
1036 }
1037 
1038 static void
1039 clean_http_auth_params(http_auth_params_t *s)
1040 {
1041 	if (s->scheme)
1042 		free(s->scheme);
1043 	if (s->realm)
1044 		free(s->realm);
1045 	if (s->user)
1046 		free(s->user);
1047 	if (s->password)
1048 		free(s->password);
1049 	init_http_auth_params(s);
1050 }
1051 
1052 static int
1053 http_authfromenv(const char *p, http_auth_params_t *parms)
1054 {
1055 	int ret = -1;
1056 	char *v, *ve;
1057 	char *str = strdup(p);
1058 
1059 	if (str == NULL) {
1060 		fetch_syserr();
1061 		return (-1);
1062 	}
1063 	v = str;
1064 
1065 	if ((ve = strchr(v, ':')) == NULL)
1066 		goto out;
1067 
1068 	*ve = 0;
1069 	if ((parms->scheme = strdup(v)) == NULL) {
1070 		fetch_syserr();
1071 		goto out;
1072 	}
1073 	v = ve + 1;
1074 
1075 	if ((ve = strchr(v, ':')) == NULL)
1076 		goto out;
1077 
1078 	*ve = 0;
1079 	if ((parms->realm = strdup(v)) == NULL) {
1080 		fetch_syserr();
1081 		goto out;
1082 	}
1083 	v = ve + 1;
1084 
1085 	if ((ve = strchr(v, ':')) == NULL)
1086 		goto out;
1087 
1088 	*ve = 0;
1089 	if ((parms->user = strdup(v)) == NULL) {
1090 		fetch_syserr();
1091 		goto out;
1092 	}
1093 	v = ve + 1;
1094 
1095 
1096 	if ((parms->password = strdup(v)) == NULL) {
1097 		fetch_syserr();
1098 		goto out;
1099 	}
1100 	ret = 0;
1101 out:
1102 	if (ret == -1)
1103 		clean_http_auth_params(parms);
1104 	if (str)
1105 		free(str);
1106 	return (ret);
1107 }
1108 
1109 
1110 /*
1111  * Digest response: the code to compute the digest is taken from the
1112  * sample implementation in RFC2616
1113  */
1114 #define IN const
1115 #define OUT
1116 
1117 #define HASHLEN 16
1118 typedef char HASH[HASHLEN];
1119 #define HASHHEXLEN 32
1120 typedef char HASHHEX[HASHHEXLEN+1];
1121 
1122 static const char *hexchars = "0123456789abcdef";
1123 static void
1124 CvtHex(IN HASH Bin, OUT HASHHEX Hex)
1125 {
1126 	unsigned short i;
1127 	unsigned char j;
1128 
1129 	for (i = 0; i < HASHLEN; i++) {
1130 		j = (Bin[i] >> 4) & 0xf;
1131 		Hex[i*2] = hexchars[j];
1132 		j = Bin[i] & 0xf;
1133 		Hex[i*2+1] = hexchars[j];
1134 	}
1135 	Hex[HASHHEXLEN] = '\0';
1136 };
1137 
1138 /* calculate H(A1) as per spec */
1139 static void
1140 DigestCalcHA1(
1141 	IN char * pszAlg,
1142 	IN char * pszUserName,
1143 	IN char * pszRealm,
1144 	IN char * pszPassword,
1145 	IN char * pszNonce,
1146 	IN char * pszCNonce,
1147 	OUT HASHHEX SessionKey
1148 	)
1149 {
1150 	MD5_CTX Md5Ctx;
1151 	HASH HA1;
1152 
1153 	MD5Init(&Md5Ctx);
1154 	MD5Update(&Md5Ctx, pszUserName, strlen(pszUserName));
1155 	MD5Update(&Md5Ctx, ":", 1);
1156 	MD5Update(&Md5Ctx, pszRealm, strlen(pszRealm));
1157 	MD5Update(&Md5Ctx, ":", 1);
1158 	MD5Update(&Md5Ctx, pszPassword, strlen(pszPassword));
1159 	MD5Final(HA1, &Md5Ctx);
1160 	if (strcasecmp(pszAlg, "md5-sess") == 0) {
1161 
1162 		MD5Init(&Md5Ctx);
1163 		MD5Update(&Md5Ctx, HA1, HASHLEN);
1164 		MD5Update(&Md5Ctx, ":", 1);
1165 		MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1166 		MD5Update(&Md5Ctx, ":", 1);
1167 		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1168 		MD5Final(HA1, &Md5Ctx);
1169 	}
1170 	CvtHex(HA1, SessionKey);
1171 }
1172 
1173 /* calculate request-digest/response-digest as per HTTP Digest spec */
1174 static void
1175 DigestCalcResponse(
1176 	IN HASHHEX HA1,           /* H(A1) */
1177 	IN char * pszNonce,       /* nonce from server */
1178 	IN char * pszNonceCount,  /* 8 hex digits */
1179 	IN char * pszCNonce,      /* client nonce */
1180 	IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
1181 	IN char * pszMethod,      /* method from the request */
1182 	IN char * pszDigestUri,   /* requested URL */
1183 	IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
1184 	OUT HASHHEX Response      /* request-digest or response-digest */
1185 	)
1186 {
1187 /*	DEBUG(fprintf(stderr,
1188 		      "Calc: HA1[%s] Nonce[%s] qop[%s] method[%s] URI[%s]\n",
1189 		      HA1, pszNonce, pszQop, pszMethod, pszDigestUri));*/
1190 	MD5_CTX Md5Ctx;
1191 	HASH HA2;
1192 	HASH RespHash;
1193 	HASHHEX HA2Hex;
1194 
1195 	// calculate H(A2)
1196 	MD5Init(&Md5Ctx);
1197 	MD5Update(&Md5Ctx, pszMethod, strlen(pszMethod));
1198 	MD5Update(&Md5Ctx, ":", 1);
1199 	MD5Update(&Md5Ctx, pszDigestUri, strlen(pszDigestUri));
1200 	if (strcasecmp(pszQop, "auth-int") == 0) {
1201 		MD5Update(&Md5Ctx, ":", 1);
1202 		MD5Update(&Md5Ctx, HEntity, HASHHEXLEN);
1203 	}
1204 	MD5Final(HA2, &Md5Ctx);
1205 	CvtHex(HA2, HA2Hex);
1206 
1207 	// calculate response
1208 	MD5Init(&Md5Ctx);
1209 	MD5Update(&Md5Ctx, HA1, HASHHEXLEN);
1210 	MD5Update(&Md5Ctx, ":", 1);
1211 	MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1212 	MD5Update(&Md5Ctx, ":", 1);
1213 	if (*pszQop) {
1214 		MD5Update(&Md5Ctx, pszNonceCount, strlen(pszNonceCount));
1215 		MD5Update(&Md5Ctx, ":", 1);
1216 		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1217 		MD5Update(&Md5Ctx, ":", 1);
1218 		MD5Update(&Md5Ctx, pszQop, strlen(pszQop));
1219 		MD5Update(&Md5Ctx, ":", 1);
1220 	}
1221 	MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
1222 	MD5Final(RespHash, &Md5Ctx);
1223 	CvtHex(RespHash, Response);
1224 }
1225 
1226 /*
1227  * Generate/Send a Digest authorization header
1228  * This looks like: [Proxy-]Authorization: credentials
1229  *
1230  *  credentials      = "Digest" digest-response
1231  *  digest-response  = 1#( username | realm | nonce | digest-uri
1232  *                      | response | [ algorithm ] | [cnonce] |
1233  *                      [opaque] | [message-qop] |
1234  *                          [nonce-count]  | [auth-param] )
1235  *  username         = "username" "=" username-value
1236  *  username-value   = quoted-string
1237  *  digest-uri       = "uri" "=" digest-uri-value
1238  *  digest-uri-value = request-uri   ; As specified by HTTP/1.1
1239  *  message-qop      = "qop" "=" qop-value
1240  *  cnonce           = "cnonce" "=" cnonce-value
1241  *  cnonce-value     = nonce-value
1242  *  nonce-count      = "nc" "=" nc-value
1243  *  nc-value         = 8LHEX
1244  *  response         = "response" "=" request-digest
1245  *  request-digest = <"> 32LHEX <">
1246  */
1247 static int
1248 http_digest_auth(conn_t *conn, const char *hdr, http_auth_challenge_t *c,
1249 		 http_auth_params_t *parms, struct url *url)
1250 {
1251 	int r;
1252 	char noncecount[10];
1253 	char cnonce[40];
1254 	char *options = NULL;
1255 
1256 	if (!c->realm || !c->nonce) {
1257 		DEBUG(fprintf(stderr, "realm/nonce not set in challenge\n"));
1258 		return(-1);
1259 	}
1260 	if (!c->algo)
1261 		c->algo = strdup("");
1262 
1263 	if (asprintf(&options, "%s%s%s%s",
1264 		     *c->algo? ",algorithm=" : "", c->algo,
1265 		     c->opaque? ",opaque=" : "", c->opaque?c->opaque:"")== -1)
1266 		return (-1);
1267 
1268 	if (!c->qop) {
1269 		c->qop = strdup("");
1270 		*noncecount = 0;
1271 		*cnonce = 0;
1272 	} else {
1273 		c->nc++;
1274 		sprintf(noncecount, "%08x", c->nc);
1275 		/* We don't try very hard with the cnonce ... */
1276 		sprintf(cnonce, "%x%lx", getpid(), (unsigned long)time(0));
1277 	}
1278 
1279 	HASHHEX HA1;
1280 	DigestCalcHA1(c->algo, parms->user, c->realm,
1281 		      parms->password, c->nonce, cnonce, HA1);
1282 	DEBUG(fprintf(stderr, "HA1: [%s]\n", HA1));
1283 	HASHHEX digest;
1284 	DigestCalcResponse(HA1, c->nonce, noncecount, cnonce, c->qop,
1285 			   "GET", url->doc, "", digest);
1286 
1287 	if (c->qop[0]) {
1288 		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1289 			     "nonce=\"%s\",uri=\"%s\",response=\"%s\","
1290 			     "qop=\"auth\", cnonce=\"%s\", nc=%s%s",
1291 			     hdr, parms->user, c->realm,
1292 			     c->nonce, url->doc, digest,
1293 			     cnonce, noncecount, options);
1294 	} else {
1295 		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1296 			     "nonce=\"%s\",uri=\"%s\",response=\"%s\"%s",
1297 			     hdr, parms->user, c->realm,
1298 			     c->nonce, url->doc, digest, options);
1299 	}
1300 	if (options)
1301 		free(options);
1302 	return (r);
1303 }
1304 
1305 /*
1306  * Encode username and password
1307  */
1308 static int
1309 http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
1310 {
1311 	char *upw, *auth;
1312 	int r;
1313 
1314 	DEBUG(fprintf(stderr, "basic: usr: [%s]\n", usr));
1315 	DEBUG(fprintf(stderr, "basic: pwd: [%s]\n", pwd));
1316 	if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
1317 		return (-1);
1318 	auth = http_base64(upw);
1319 	free(upw);
1320 	if (auth == NULL)
1321 		return (-1);
1322 	r = http_cmd(conn, "%s: Basic %s", hdr, auth);
1323 	free(auth);
1324 	return (r);
1325 }
1326 
1327 /*
1328  * Chose the challenge to answer and call the appropriate routine to
1329  * produce the header.
1330  */
1331 static int
1332 http_authorize(conn_t *conn, const char *hdr, http_auth_challenges_t *cs,
1333 	       http_auth_params_t *parms, struct url *url)
1334 {
1335 	http_auth_challenge_t *digest = NULL;
1336 	int i;
1337 
1338 	/* If user or pass are null we're not happy */
1339 	if (!parms->user || !parms->password) {
1340 		DEBUG(fprintf(stderr, "NULL usr or pass\n"));
1341 		return (-1);
1342 	}
1343 
1344 	/* Look for a Digest */
1345 	for (i = 0; i < cs->count; i++) {
1346 		if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1347 			digest = cs->challenges[i];
1348 	}
1349 
1350 	/* Error if "Digest" was specified and there is no Digest challenge */
1351 	if (!digest && (parms->scheme &&
1352 			!strcasecmp(parms->scheme, "digest"))) {
1353 		DEBUG(fprintf(stderr,
1354 			      "Digest auth in env, not supported by peer\n"));
1355 		return (-1);
1356 	}
1357 	/*
1358 	 * If "basic" was specified in the environment, or there is no Digest
1359 	 * challenge, do the basic thing. Don't need a challenge for this,
1360 	 * so no need to check basic!=NULL
1361 	 */
1362 	if (!digest || (parms->scheme && !strcasecmp(parms->scheme,"basic")))
1363 		return (http_basic_auth(conn,hdr,parms->user,parms->password));
1364 
1365 	/* Else, prefer digest. We just checked that it's not NULL */
1366 	return (http_digest_auth(conn, hdr, digest, parms, url));
1367 }
1368 
1369 /*****************************************************************************
1370  * Helper functions for connecting to a server or proxy
1371  */
1372 
1373 /*
1374  * Connect to the correct HTTP server or proxy.
1375  */
1376 static conn_t *
1377 http_connect(struct url *URL, struct url *purl, const char *flags)
1378 {
1379 	struct url *curl;
1380 	conn_t *conn;
1381 	hdr_t h;
1382 	http_headerbuf_t headerbuf;
1383 	const char *p;
1384 	int verbose;
1385 	int af, val;
1386 	int serrno;
1387 
1388 #ifdef INET6
1389 	af = AF_UNSPEC;
1390 #else
1391 	af = AF_INET;
1392 #endif
1393 
1394 	verbose = CHECK_FLAG('v');
1395 	if (CHECK_FLAG('4'))
1396 		af = AF_INET;
1397 #ifdef INET6
1398 	else if (CHECK_FLAG('6'))
1399 		af = AF_INET6;
1400 #endif
1401 
1402 	curl = (purl != NULL) ? purl : URL;
1403 
1404 	if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1405 		/* fetch_connect() has already set an error code */
1406 		return (NULL);
1407 	init_http_headerbuf(&headerbuf);
1408 	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1409 		http_cmd(conn, "CONNECT %s:%d HTTP/1.1",
1410 		    URL->host, URL->port);
1411 		http_cmd(conn, "Host: %s:%d",
1412 		    URL->host, URL->port);
1413 		http_cmd(conn, "");
1414 		if (http_get_reply(conn) != HTTP_OK) {
1415 			http_seterr(conn->err);
1416 			goto ouch;
1417 		}
1418 		/* Read and discard the rest of the proxy response */
1419 		if (fetch_getln(conn) < 0) {
1420 			fetch_syserr();
1421 			goto ouch;
1422 		}
1423 		do {
1424 			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1425 			case hdr_syserror:
1426 				fetch_syserr();
1427 				goto ouch;
1428 			case hdr_error:
1429 				http_seterr(HTTP_PROTOCOL_ERROR);
1430 				goto ouch;
1431 			default:
1432 				/* ignore */ ;
1433 			}
1434 		} while (h < hdr_end);
1435 	}
1436 	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1437 	    fetch_ssl(conn, URL, verbose) == -1) {
1438 		/* grrr */
1439 		errno = EAUTH;
1440 		fetch_syserr();
1441 		goto ouch;
1442 	}
1443 
1444 	val = 1;
1445 	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1446 
1447 	clean_http_headerbuf(&headerbuf);
1448 	return (conn);
1449 ouch:
1450 	serrno = errno;
1451 	clean_http_headerbuf(&headerbuf);
1452 	fetch_close(conn);
1453 	errno = serrno;
1454 	return (NULL);
1455 }
1456 
1457 static struct url *
1458 http_get_proxy(struct url * url, const char *flags)
1459 {
1460 	struct url *purl;
1461 	char *p;
1462 
1463 	if (flags != NULL && strchr(flags, 'd') != NULL)
1464 		return (NULL);
1465 	if (fetch_no_proxy_match(url->host))
1466 		return (NULL);
1467 	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1468 	    *p && (purl = fetchParseURL(p))) {
1469 		if (!*purl->scheme)
1470 			strcpy(purl->scheme, SCHEME_HTTP);
1471 		if (!purl->port)
1472 			purl->port = fetch_default_proxy_port(purl->scheme);
1473 		if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1474 			return (purl);
1475 		fetchFreeURL(purl);
1476 	}
1477 	return (NULL);
1478 }
1479 
1480 static void
1481 http_print_html(FILE *out, FILE *in)
1482 {
1483 	size_t len;
1484 	char *line, *p, *q;
1485 	int comment, tag;
1486 
1487 	comment = tag = 0;
1488 	while ((line = fgetln(in, &len)) != NULL) {
1489 		while (len && isspace((unsigned char)line[len - 1]))
1490 			--len;
1491 		for (p = q = line; q < line + len; ++q) {
1492 			if (comment && *q == '-') {
1493 				if (q + 2 < line + len &&
1494 				    strcmp(q, "-->") == 0) {
1495 					tag = comment = 0;
1496 					q += 2;
1497 				}
1498 			} else if (tag && !comment && *q == '>') {
1499 				p = q + 1;
1500 				tag = 0;
1501 			} else if (!tag && *q == '<') {
1502 				if (q > p)
1503 					fwrite(p, q - p, 1, out);
1504 				tag = 1;
1505 				if (q + 3 < line + len &&
1506 				    strcmp(q, "<!--") == 0) {
1507 					comment = 1;
1508 					q += 3;
1509 				}
1510 			}
1511 		}
1512 		if (!tag && q > p)
1513 			fwrite(p, q - p, 1, out);
1514 		fputc('\n', out);
1515 	}
1516 }
1517 
1518 
1519 /*****************************************************************************
1520  * Core
1521  */
1522 
1523 FILE *
1524 http_request(struct url *URL, const char *op, struct url_stat *us,
1525 	struct url *purl, const char *flags)
1526 {
1527 
1528 	return (http_request_body(URL, op, us, purl, flags, NULL, NULL));
1529 }
1530 
1531 /*
1532  * Send a request and process the reply
1533  *
1534  * XXX This function is way too long, the do..while loop should be split
1535  * XXX off into a separate function.
1536  */
1537 FILE *
1538 http_request_body(struct url *URL, const char *op, struct url_stat *us,
1539 	struct url *purl, const char *flags, const char *content_type,
1540 	const char *body)
1541 {
1542 	char timebuf[80];
1543 	char hbuf[MAXHOSTNAMELEN + 7], *host;
1544 	conn_t *conn;
1545 	struct url *url, *new;
1546 	int chunked, direct, ims, noredirect, verbose;
1547 	int e, i, n, val;
1548 	off_t offset, clength, length, size;
1549 	time_t mtime;
1550 	const char *p;
1551 	FILE *f;
1552 	hdr_t h;
1553 	struct tm *timestruct;
1554 	http_headerbuf_t headerbuf;
1555 	http_auth_challenges_t server_challenges;
1556 	http_auth_challenges_t proxy_challenges;
1557 	size_t body_len;
1558 
1559 	/* The following calls don't allocate anything */
1560 	init_http_headerbuf(&headerbuf);
1561 	init_http_auth_challenges(&server_challenges);
1562 	init_http_auth_challenges(&proxy_challenges);
1563 
1564 	direct = CHECK_FLAG('d');
1565 	noredirect = CHECK_FLAG('A');
1566 	verbose = CHECK_FLAG('v');
1567 	ims = CHECK_FLAG('i');
1568 
1569 	if (direct && purl) {
1570 		fetchFreeURL(purl);
1571 		purl = NULL;
1572 	}
1573 
1574 	/* try the provided URL first */
1575 	url = URL;
1576 
1577 	n = MAX_REDIRECT;
1578 	i = 0;
1579 
1580 	e = HTTP_PROTOCOL_ERROR;
1581 	do {
1582 		new = NULL;
1583 		chunked = 0;
1584 		offset = 0;
1585 		clength = -1;
1586 		length = -1;
1587 		size = -1;
1588 		mtime = 0;
1589 
1590 		/* check port */
1591 		if (!url->port)
1592 			url->port = fetch_default_port(url->scheme);
1593 
1594 		/* were we redirected to an FTP URL? */
1595 		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1596 			if (strcmp(op, "GET") == 0)
1597 				return (ftp_request(url, "RETR", us, purl, flags));
1598 			else if (strcmp(op, "HEAD") == 0)
1599 				return (ftp_request(url, "STAT", us, purl, flags));
1600 		}
1601 
1602 		/* connect to server or proxy */
1603 		if ((conn = http_connect(url, purl, flags)) == NULL)
1604 			goto ouch;
1605 
1606 		host = url->host;
1607 #ifdef INET6
1608 		if (strchr(url->host, ':')) {
1609 			snprintf(hbuf, sizeof(hbuf), "[%s]", url->host);
1610 			host = hbuf;
1611 		}
1612 #endif
1613 		if (url->port != fetch_default_port(url->scheme)) {
1614 			if (host != hbuf) {
1615 				strcpy(hbuf, host);
1616 				host = hbuf;
1617 			}
1618 			snprintf(hbuf + strlen(hbuf),
1619 			    sizeof(hbuf) - strlen(hbuf), ":%d", url->port);
1620 		}
1621 
1622 		/* send request */
1623 		if (verbose)
1624 			fetch_info("requesting %s://%s%s",
1625 			    url->scheme, host, url->doc);
1626 		if (purl && strcasecmp(URL->scheme, SCHEME_HTTPS) != 0) {
1627 			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1628 			    op, url->scheme, host, url->doc);
1629 		} else {
1630 			http_cmd(conn, "%s %s HTTP/1.1",
1631 			    op, url->doc);
1632 		}
1633 
1634 		if (ims && url->ims_time) {
1635 			timestruct = gmtime((time_t *)&url->ims_time);
1636 			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1637 			    timestruct);
1638 			if (verbose)
1639 				fetch_info("If-Modified-Since: %s", timebuf);
1640 			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1641 		}
1642 		/* virtual host */
1643 		http_cmd(conn, "Host: %s", host);
1644 
1645 		/*
1646 		 * Proxy authorization: we only send auth after we received
1647 		 * a 407 error. We do not first try basic anyway (changed
1648 		 * when support was added for digest-auth)
1649 		 */
1650 		if (purl && proxy_challenges.valid) {
1651 			http_auth_params_t aparams;
1652 			init_http_auth_params(&aparams);
1653 			if (*purl->user || *purl->pwd) {
1654 				aparams.user = strdup(purl->user);
1655 				aparams.password = strdup(purl->pwd);
1656 			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1657 				   *p != '\0') {
1658 				if (http_authfromenv(p, &aparams) < 0) {
1659 					http_seterr(HTTP_NEED_PROXY_AUTH);
1660 					goto ouch;
1661 				}
1662 			} else if (fetch_netrc_auth(purl) == 0) {
1663 				aparams.user = strdup(purl->user);
1664 				aparams.password = strdup(purl->pwd);
1665 			}
1666 			http_authorize(conn, "Proxy-Authorization",
1667 				       &proxy_challenges, &aparams, url);
1668 			clean_http_auth_params(&aparams);
1669 		}
1670 
1671 		/*
1672 		 * Server authorization: we never send "a priori"
1673 		 * Basic auth, which used to be done if user/pass were
1674 		 * set in the url. This would be weird because we'd send the
1675 		 * password in the clear even if Digest is finally to be
1676 		 * used (it would have made more sense for the
1677 		 * pre-digest version to do this when Basic was specified
1678 		 * in the environment)
1679 		 */
1680 		if (server_challenges.valid) {
1681 			http_auth_params_t aparams;
1682 			init_http_auth_params(&aparams);
1683 			if (*url->user || *url->pwd) {
1684 				aparams.user = strdup(url->user);
1685 				aparams.password = strdup(url->pwd);
1686 			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1687 				   *p != '\0') {
1688 				if (http_authfromenv(p, &aparams) < 0) {
1689 					http_seterr(HTTP_NEED_AUTH);
1690 					goto ouch;
1691 				}
1692 			} else if (fetch_netrc_auth(url) == 0) {
1693 				aparams.user = strdup(url->user);
1694 				aparams.password = strdup(url->pwd);
1695 			} else if (fetchAuthMethod &&
1696 				   fetchAuthMethod(url) == 0) {
1697 				aparams.user = strdup(url->user);
1698 				aparams.password = strdup(url->pwd);
1699 			} else {
1700 				http_seterr(HTTP_NEED_AUTH);
1701 				goto ouch;
1702 			}
1703 			http_authorize(conn, "Authorization",
1704 				       &server_challenges, &aparams, url);
1705 			clean_http_auth_params(&aparams);
1706 		}
1707 
1708 		/* other headers */
1709 		if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1710 			if (*p != '\0')
1711 				http_cmd(conn, "Accept: %s", p);
1712 		} else {
1713 			http_cmd(conn, "Accept: */*");
1714 		}
1715 		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1716 			if (strcasecmp(p, "auto") == 0)
1717 				http_cmd(conn, "Referer: %s://%s%s",
1718 				    url->scheme, host, url->doc);
1719 			else
1720 				http_cmd(conn, "Referer: %s", p);
1721 		}
1722 		if ((p = getenv("HTTP_USER_AGENT")) != NULL) {
1723 			/* no User-Agent if defined but empty */
1724 			if  (*p != '\0')
1725 				http_cmd(conn, "User-Agent: %s", p);
1726 		} else {
1727 			/* default User-Agent */
1728 			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER,
1729 			    getprogname());
1730 		}
1731 		if (url->offset > 0)
1732 			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1733 		http_cmd(conn, "Connection: close");
1734 
1735 		if (body) {
1736 			body_len = strlen(body);
1737 			http_cmd(conn, "Content-Length: %zu", body_len);
1738 			if (content_type != NULL)
1739 				http_cmd(conn, "Content-Type: %s", content_type);
1740 		}
1741 
1742 		http_cmd(conn, "");
1743 
1744 		if (body)
1745 			fetch_write(conn, body, body_len);
1746 
1747 		/*
1748 		 * Force the queued request to be dispatched.  Normally, one
1749 		 * would do this with shutdown(2) but squid proxies can be
1750 		 * configured to disallow such half-closed connections.  To
1751 		 * be compatible with such configurations, fiddle with socket
1752 		 * options to force the pending data to be written.
1753 		 */
1754 		val = 0;
1755 		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1756 			   sizeof(val));
1757 		val = 1;
1758 		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1759 			   sizeof(val));
1760 
1761 		/* get reply */
1762 		switch (http_get_reply(conn)) {
1763 		case HTTP_OK:
1764 		case HTTP_PARTIAL:
1765 		case HTTP_NOT_MODIFIED:
1766 			/* fine */
1767 			break;
1768 		case HTTP_MOVED_PERM:
1769 		case HTTP_MOVED_TEMP:
1770 		case HTTP_SEE_OTHER:
1771 		case HTTP_USE_PROXY:
1772 			/*
1773 			 * Not so fine, but we still have to read the
1774 			 * headers to get the new location.
1775 			 */
1776 			break;
1777 		case HTTP_NEED_AUTH:
1778 			if (server_challenges.valid) {
1779 				/*
1780 				 * We already sent out authorization code,
1781 				 * so there's nothing more we can do.
1782 				 */
1783 				http_seterr(conn->err);
1784 				goto ouch;
1785 			}
1786 			/* try again, but send the password this time */
1787 			if (verbose)
1788 				fetch_info("server requires authorization");
1789 			break;
1790 		case HTTP_NEED_PROXY_AUTH:
1791 			if (proxy_challenges.valid) {
1792 				/*
1793 				 * We already sent our proxy
1794 				 * authorization code, so there's
1795 				 * nothing more we can do. */
1796 				http_seterr(conn->err);
1797 				goto ouch;
1798 			}
1799 			/* try again, but send the password this time */
1800 			if (verbose)
1801 				fetch_info("proxy requires authorization");
1802 			break;
1803 		case HTTP_BAD_RANGE:
1804 			/*
1805 			 * This can happen if we ask for 0 bytes because
1806 			 * we already have the whole file.  Consider this
1807 			 * a success for now, and check sizes later.
1808 			 */
1809 			break;
1810 		case HTTP_PROTOCOL_ERROR:
1811 			/* fall through */
1812 		case -1:
1813 			fetch_syserr();
1814 			goto ouch;
1815 		default:
1816 			http_seterr(conn->err);
1817 			if (!verbose)
1818 				goto ouch;
1819 			/* fall through so we can get the full error message */
1820 		}
1821 
1822 		/* get headers. http_next_header expects one line readahead */
1823 		if (fetch_getln(conn) == -1) {
1824 			fetch_syserr();
1825 			goto ouch;
1826 		}
1827 		do {
1828 			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1829 			case hdr_syserror:
1830 				fetch_syserr();
1831 				goto ouch;
1832 			case hdr_error:
1833 				http_seterr(HTTP_PROTOCOL_ERROR);
1834 				goto ouch;
1835 			case hdr_content_length:
1836 				http_parse_length(p, &clength);
1837 				break;
1838 			case hdr_content_range:
1839 				http_parse_range(p, &offset, &length, &size);
1840 				break;
1841 			case hdr_last_modified:
1842 				http_parse_mtime(p, &mtime);
1843 				break;
1844 			case hdr_location:
1845 				if (!HTTP_REDIRECT(conn->err))
1846 					break;
1847 				/*
1848 				 * if the A flag is set, we don't follow
1849 				 * temporary redirects.
1850 				 */
1851 				if (noredirect &&
1852 				    conn->err != HTTP_MOVED_PERM &&
1853 				    conn->err != HTTP_PERM_REDIRECT &&
1854 				    conn->err != HTTP_USE_PROXY) {
1855 					n = 1;
1856 					break;
1857 				}
1858 				if (new)
1859 					free(new);
1860 				if (verbose)
1861 					fetch_info("%d redirect to %s", conn->err, p);
1862 				if (*p == '/')
1863 					/* absolute path */
1864 					new = fetchMakeURL(url->scheme, url->host, url->port, p,
1865 					    url->user, url->pwd);
1866 				else
1867 					new = fetchParseURL(p);
1868 				if (new == NULL) {
1869 					/* XXX should set an error code */
1870 					DEBUG(fprintf(stderr, "failed to parse new URL\n"));
1871 					goto ouch;
1872 				}
1873 
1874 				/* Only copy credentials if the host matches */
1875 				if (!strcmp(new->host, url->host) && !*new->user && !*new->pwd) {
1876 					strcpy(new->user, url->user);
1877 					strcpy(new->pwd, url->pwd);
1878 				}
1879 				new->offset = url->offset;
1880 				new->length = url->length;
1881 				break;
1882 			case hdr_transfer_encoding:
1883 				/* XXX weak test*/
1884 				chunked = (strcasecmp(p, "chunked") == 0);
1885 				break;
1886 			case hdr_www_authenticate:
1887 				if (conn->err != HTTP_NEED_AUTH)
1888 					break;
1889 				if (http_parse_authenticate(p, &server_challenges) == 0)
1890 					++n;
1891 				break;
1892 			case hdr_proxy_authenticate:
1893 				if (conn->err != HTTP_NEED_PROXY_AUTH)
1894 					break;
1895 				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1896 					++n;
1897 				break;
1898 			case hdr_end:
1899 				/* fall through */
1900 			case hdr_unknown:
1901 				/* ignore */
1902 				break;
1903 			}
1904 		} while (h > hdr_end);
1905 
1906 		/* we need to provide authentication */
1907 		if (conn->err == HTTP_NEED_AUTH ||
1908 		    conn->err == HTTP_NEED_PROXY_AUTH) {
1909 			e = conn->err;
1910 			if ((conn->err == HTTP_NEED_AUTH &&
1911 			     !server_challenges.valid) ||
1912 			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1913 			     !proxy_challenges.valid)) {
1914 				/* 401/7 but no www/proxy-authenticate ?? */
1915 				DEBUG(fprintf(stderr, "401/7 and no auth header\n"));
1916 				goto ouch;
1917 			}
1918 			fetch_close(conn);
1919 			conn = NULL;
1920 			continue;
1921 		}
1922 
1923 		/* requested range not satisfiable */
1924 		if (conn->err == HTTP_BAD_RANGE) {
1925 			if (url->offset == size && url->length == 0) {
1926 				/* asked for 0 bytes; fake it */
1927 				offset = url->offset;
1928 				clength = -1;
1929 				conn->err = HTTP_OK;
1930 				break;
1931 			} else {
1932 				http_seterr(conn->err);
1933 				goto ouch;
1934 			}
1935 		}
1936 
1937 		/* we have a hit or an error */
1938 		if (conn->err == HTTP_OK
1939 		    || conn->err == HTTP_NOT_MODIFIED
1940 		    || conn->err == HTTP_PARTIAL
1941 		    || HTTP_ERROR(conn->err))
1942 			break;
1943 
1944 		/* all other cases: we got a redirect */
1945 		e = conn->err;
1946 		clean_http_auth_challenges(&server_challenges);
1947 		fetch_close(conn);
1948 		conn = NULL;
1949 		if (!new) {
1950 			DEBUG(fprintf(stderr, "redirect with no new location\n"));
1951 			break;
1952 		}
1953 		if (url != URL)
1954 			fetchFreeURL(url);
1955 		url = new;
1956 	} while (++i < n);
1957 
1958 	/* we failed, or ran out of retries */
1959 	if (conn == NULL) {
1960 		http_seterr(e);
1961 		goto ouch;
1962 	}
1963 
1964 	DEBUG(fprintf(stderr, "offset %lld, length %lld,"
1965 		  " size %lld, clength %lld\n",
1966 		  (long long)offset, (long long)length,
1967 		  (long long)size, (long long)clength));
1968 
1969 	if (conn->err == HTTP_NOT_MODIFIED) {
1970 		http_seterr(HTTP_NOT_MODIFIED);
1971 		return (NULL);
1972 	}
1973 
1974 	/* check for inconsistencies */
1975 	if (clength != -1 && length != -1 && clength != length) {
1976 		http_seterr(HTTP_PROTOCOL_ERROR);
1977 		goto ouch;
1978 	}
1979 	if (clength == -1)
1980 		clength = length;
1981 	if (clength != -1)
1982 		length = offset + clength;
1983 	if (length != -1 && size != -1 && length != size) {
1984 		http_seterr(HTTP_PROTOCOL_ERROR);
1985 		goto ouch;
1986 	}
1987 	if (size == -1)
1988 		size = length;
1989 
1990 	/* fill in stats */
1991 	if (us) {
1992 		us->size = size;
1993 		us->atime = us->mtime = mtime;
1994 	}
1995 
1996 	/* too far? */
1997 	if (URL->offset > 0 && offset > URL->offset) {
1998 		http_seterr(HTTP_PROTOCOL_ERROR);
1999 		goto ouch;
2000 	}
2001 
2002 	/* report back real offset and size */
2003 	URL->offset = offset;
2004 	URL->length = clength;
2005 
2006 	/* wrap it up in a FILE */
2007 	if ((f = http_funopen(conn, chunked)) == NULL) {
2008 		fetch_syserr();
2009 		goto ouch;
2010 	}
2011 
2012 	if (url != URL)
2013 		fetchFreeURL(url);
2014 	if (purl)
2015 		fetchFreeURL(purl);
2016 
2017 	if (HTTP_ERROR(conn->err)) {
2018 		http_print_html(stderr, f);
2019 		fclose(f);
2020 		f = NULL;
2021 	}
2022 	clean_http_headerbuf(&headerbuf);
2023 	clean_http_auth_challenges(&server_challenges);
2024 	clean_http_auth_challenges(&proxy_challenges);
2025 	return (f);
2026 
2027 ouch:
2028 	if (url != URL)
2029 		fetchFreeURL(url);
2030 	if (purl)
2031 		fetchFreeURL(purl);
2032 	if (conn != NULL)
2033 		fetch_close(conn);
2034 	clean_http_headerbuf(&headerbuf);
2035 	clean_http_auth_challenges(&server_challenges);
2036 	clean_http_auth_challenges(&proxy_challenges);
2037 	return (NULL);
2038 }
2039 
2040 
2041 /*****************************************************************************
2042  * Entry points
2043  */
2044 
2045 /*
2046  * Retrieve and stat a file by HTTP
2047  */
2048 FILE *
2049 fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
2050 {
2051 	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
2052 }
2053 
2054 /*
2055  * Retrieve a file by HTTP
2056  */
2057 FILE *
2058 fetchGetHTTP(struct url *URL, const char *flags)
2059 {
2060 	return (fetchXGetHTTP(URL, NULL, flags));
2061 }
2062 
2063 /*
2064  * Store a file by HTTP
2065  */
2066 FILE *
2067 fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2068 {
2069 	warnx("fetchPutHTTP(): not implemented");
2070 	return (NULL);
2071 }
2072 
2073 /*
2074  * Get an HTTP document's metadata
2075  */
2076 int
2077 fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2078 {
2079 	FILE *f;
2080 
2081 	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2082 	if (f == NULL)
2083 		return (-1);
2084 	fclose(f);
2085 	return (0);
2086 }
2087 
2088 /*
2089  * List a directory
2090  */
2091 struct url_ent *
2092 fetchListHTTP(struct url *url __unused, const char *flags __unused)
2093 {
2094 	warnx("fetchListHTTP(): not implemented");
2095 	return (NULL);
2096 }
2097 
2098 FILE *
2099 fetchReqHTTP(struct url *URL, const char *method, const char *flags,
2100 	const char *content_type, const char *body)
2101 {
2102 
2103 	return (http_request_body(URL, method, NULL, http_get_proxy(URL, flags),
2104 	    flags, content_type, body));
2105 }
2106