http.c revision 291461 
1/*-
2 * Copyright (c) 2000-2014 Dag-Erling Sm��rgrav
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: head/lib/libfetch/http.c 291461 2015-11-29 22:37:48Z dim $");
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
127struct 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 */
146static int
147http_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 */
189static inline int
190http_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 */
207static ssize_t
208http_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 */
266static int
267http_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 */
299static int
300http_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 */
310static int
311http_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 */
326static FILE *
327http_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 */
353typedef 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 */
368static 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 */
385static int
386http_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 */
417static int
418http_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 */
455static const char *
456http_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 */
492typedef struct {
493	char	*buf;		/* buffer */
494	size_t	 bufsize;	/* buffer size */
495	size_t	 buflen;	/* length of buffer contents */
496} http_headerbuf_t;
497
498static void
499init_http_headerbuf(http_headerbuf_t *buf)
500{
501	buf->buf = NULL;
502	buf->bufsize = 0;
503	buf->buflen = 0;
504}
505
506static void
507clean_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 */
515static void
516http_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
524static hdr_t
525http_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 */
601static const char *
602http_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 */
625typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
626
627/* Data holder for a Basic or Digest challenge. */
628typedef 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
639static void
640init_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
647static void
648clean_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
665typedef 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
671static void
672init_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
680static void
681clean_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 */
698typedef 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 */
706static int
707http_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 */
747static int
748http_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
856out:
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 */
870static int
871http_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 */
900static int
901http_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 */
918static int
919http_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 */
965static char *
966http_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 */
1023typedef struct {
1024	char	*scheme;
1025	char	*realm;
1026	char	*user;
1027	char	*password;
1028} http_auth_params_t;
1029
1030static void
1031init_http_auth_params(http_auth_params_t *s)
1032{
1033	s->scheme = s->realm = s->user = s->password = NULL;
1034}
1035
1036static void
1037clean_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
1050static int
1051http_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;
1099out:
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
1116typedef char HASH[HASHLEN];
1117#define HASHHEXLEN 32
1118typedef char HASHHEX[HASHHEXLEN+1];
1119
1120static const char *hexchars = "0123456789abcdef";
1121static void
1122CvtHex(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 */
1137static void
1138DigestCalcHA1(
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 */
1172static void
1173DigestCalcResponse(
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 */
1245static int
1246http_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 */
1306static int
1307http_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 */
1329static int
1330http_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 *digest = NULL;
1334	int i;
1335
1336	/* If user or pass are null we're not happy */
1337	if (!parms->user || !parms->password) {
1338		DEBUG(fprintf(stderr, "NULL usr or pass\n"));
1339		return (-1);
1340	}
1341
1342	/* Look for a Digest */
1343	for (i = 0; i < cs->count; i++) {
1344		if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1345			digest = cs->challenges[i];
1346	}
1347
1348	/* Error if "Digest" was specified and there is no Digest challenge */
1349	if (!digest && (parms->scheme &&
1350			!strcasecmp(parms->scheme, "digest"))) {
1351		DEBUG(fprintf(stderr,
1352			      "Digest auth in env, not supported by peer\n"));
1353		return (-1);
1354	}
1355	/*
1356	 * If "basic" was specified in the environment, or there is no Digest
1357	 * challenge, do the basic thing. Don't need a challenge for this,
1358	 * so no need to check basic!=NULL
1359	 */
1360	if (!digest || (parms->scheme && !strcasecmp(parms->scheme,"basic")))
1361		return (http_basic_auth(conn,hdr,parms->user,parms->password));
1362
1363	/* Else, prefer digest. We just checked that it's not NULL */
1364	return (http_digest_auth(conn, hdr, digest, parms, url));
1365}
1366
1367/*****************************************************************************
1368 * Helper functions for connecting to a server or proxy
1369 */
1370
1371/*
1372 * Connect to the correct HTTP server or proxy.
1373 */
1374static conn_t *
1375http_connect(struct url *URL, struct url *purl, const char *flags)
1376{
1377	struct url *curl;
1378	conn_t *conn;
1379	hdr_t h;
1380	http_headerbuf_t headerbuf;
1381	const char *p;
1382	int verbose;
1383	int af, val;
1384	int serrno;
1385
1386#ifdef INET6
1387	af = AF_UNSPEC;
1388#else
1389	af = AF_INET;
1390#endif
1391
1392	verbose = CHECK_FLAG('v');
1393	if (CHECK_FLAG('4'))
1394		af = AF_INET;
1395#ifdef INET6
1396	else if (CHECK_FLAG('6'))
1397		af = AF_INET6;
1398#endif
1399
1400	curl = (purl != NULL) ? purl : URL;
1401
1402	if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1403		/* fetch_connect() has already set an error code */
1404		return (NULL);
1405	init_http_headerbuf(&headerbuf);
1406	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1407		http_cmd(conn, "CONNECT %s:%d HTTP/1.1",
1408		    URL->host, URL->port);
1409		http_cmd(conn, "Host: %s:%d",
1410		    URL->host, URL->port);
1411		http_cmd(conn, "");
1412		if (http_get_reply(conn) != HTTP_OK) {
1413			http_seterr(conn->err);
1414			goto ouch;
1415		}
1416		/* Read and discard the rest of the proxy response */
1417		if (fetch_getln(conn) < 0) {
1418			fetch_syserr();
1419			goto ouch;
1420		}
1421		do {
1422			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1423			case hdr_syserror:
1424				fetch_syserr();
1425				goto ouch;
1426			case hdr_error:
1427				http_seterr(HTTP_PROTOCOL_ERROR);
1428				goto ouch;
1429			default:
1430				/* ignore */ ;
1431			}
1432		} while (h < hdr_end);
1433	}
1434	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1435	    fetch_ssl(conn, URL, verbose) == -1) {
1436		fetch_close(conn);
1437		/* grrr */
1438		errno = EAUTH;
1439		fetch_syserr();
1440		goto ouch;
1441	}
1442
1443	val = 1;
1444	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1445
1446	clean_http_headerbuf(&headerbuf);
1447	return (conn);
1448ouch:
1449	serrno = errno;
1450	clean_http_headerbuf(&headerbuf);
1451	fetch_close(conn);
1452	errno = serrno;
1453	return (NULL);
1454}
1455
1456static struct url *
1457http_get_proxy(struct url * url, const char *flags)
1458{
1459	struct url *purl;
1460	char *p;
1461
1462	if (flags != NULL && strchr(flags, 'd') != NULL)
1463		return (NULL);
1464	if (fetch_no_proxy_match(url->host))
1465		return (NULL);
1466	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1467	    *p && (purl = fetchParseURL(p))) {
1468		if (!*purl->scheme)
1469			strcpy(purl->scheme, SCHEME_HTTP);
1470		if (!purl->port)
1471			purl->port = fetch_default_proxy_port(purl->scheme);
1472		if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1473			return (purl);
1474		fetchFreeURL(purl);
1475	}
1476	return (NULL);
1477}
1478
1479static void
1480http_print_html(FILE *out, FILE *in)
1481{
1482	size_t len;
1483	char *line, *p, *q;
1484	int comment, tag;
1485
1486	comment = tag = 0;
1487	while ((line = fgetln(in, &len)) != NULL) {
1488		while (len && isspace((unsigned char)line[len - 1]))
1489			--len;
1490		for (p = q = line; q < line + len; ++q) {
1491			if (comment && *q == '-') {
1492				if (q + 2 < line + len &&
1493				    strcmp(q, "-->") == 0) {
1494					tag = comment = 0;
1495					q += 2;
1496				}
1497			} else if (tag && !comment && *q == '>') {
1498				p = q + 1;
1499				tag = 0;
1500			} else if (!tag && *q == '<') {
1501				if (q > p)
1502					fwrite(p, q - p, 1, out);
1503				tag = 1;
1504				if (q + 3 < line + len &&
1505				    strcmp(q, "<!--") == 0) {
1506					comment = 1;
1507					q += 3;
1508				}
1509			}
1510		}
1511		if (!tag && q > p)
1512			fwrite(p, q - p, 1, out);
1513		fputc('\n', out);
1514	}
1515}
1516
1517
1518/*****************************************************************************
1519 * Core
1520 */
1521
1522FILE *
1523http_request(struct url *URL, const char *op, struct url_stat *us,
1524	struct url *purl, const char *flags)
1525{
1526
1527	return (http_request_body(URL, op, us, purl, flags, NULL, NULL));
1528}
1529
1530/*
1531 * Send a request and process the reply
1532 *
1533 * XXX This function is way too long, the do..while loop should be split
1534 * XXX off into a separate function.
1535 */
1536FILE *
1537http_request_body(struct url *URL, const char *op, struct url_stat *us,
1538	struct url *purl, const char *flags, const char *content_type,
1539	const char *body)
1540{
1541	char timebuf[80];
1542	char hbuf[MAXHOSTNAMELEN + 7], *host;
1543	conn_t *conn;
1544	struct url *url, *new;
1545	int chunked, direct, ims, noredirect, verbose;
1546	int e, i, n, val;
1547	off_t offset, clength, length, size;
1548	time_t mtime;
1549	const char *p;
1550	FILE *f;
1551	hdr_t h;
1552	struct tm *timestruct;
1553	http_headerbuf_t headerbuf;
1554	http_auth_challenges_t server_challenges;
1555	http_auth_challenges_t proxy_challenges;
1556	size_t body_len;
1557
1558	/* The following calls don't allocate anything */
1559	init_http_headerbuf(&headerbuf);
1560	init_http_auth_challenges(&server_challenges);
1561	init_http_auth_challenges(&proxy_challenges);
1562
1563	direct = CHECK_FLAG('d');
1564	noredirect = CHECK_FLAG('A');
1565	verbose = CHECK_FLAG('v');
1566	ims = CHECK_FLAG('i');
1567
1568	if (direct && purl) {
1569		fetchFreeURL(purl);
1570		purl = NULL;
1571	}
1572
1573	/* try the provided URL first */
1574	url = URL;
1575
1576	n = MAX_REDIRECT;
1577	i = 0;
1578
1579	e = HTTP_PROTOCOL_ERROR;
1580	do {
1581		new = NULL;
1582		chunked = 0;
1583		offset = 0;
1584		clength = -1;
1585		length = -1;
1586		size = -1;
1587		mtime = 0;
1588
1589		/* check port */
1590		if (!url->port)
1591			url->port = fetch_default_port(url->scheme);
1592
1593		/* were we redirected to an FTP URL? */
1594		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1595			if (strcmp(op, "GET") == 0)
1596				return (ftp_request(url, "RETR", us, purl, flags));
1597			else if (strcmp(op, "HEAD") == 0)
1598				return (ftp_request(url, "STAT", us, purl, flags));
1599		}
1600
1601		/* connect to server or proxy */
1602		if ((conn = http_connect(url, purl, flags)) == NULL)
1603			goto ouch;
1604
1605		host = url->host;
1606#ifdef INET6
1607		if (strchr(url->host, ':')) {
1608			snprintf(hbuf, sizeof(hbuf), "[%s]", url->host);
1609			host = hbuf;
1610		}
1611#endif
1612		if (url->port != fetch_default_port(url->scheme)) {
1613			if (host != hbuf) {
1614				strcpy(hbuf, host);
1615				host = hbuf;
1616			}
1617			snprintf(hbuf + strlen(hbuf),
1618			    sizeof(hbuf) - strlen(hbuf), ":%d", url->port);
1619		}
1620
1621		/* send request */
1622		if (verbose)
1623			fetch_info("requesting %s://%s%s",
1624			    url->scheme, host, url->doc);
1625		if (purl && strcasecmp(URL->scheme, SCHEME_HTTPS) != 0) {
1626			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1627			    op, url->scheme, host, url->doc);
1628		} else {
1629			http_cmd(conn, "%s %s HTTP/1.1",
1630			    op, url->doc);
1631		}
1632
1633		if (ims && url->ims_time) {
1634			timestruct = gmtime((time_t *)&url->ims_time);
1635			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1636			    timestruct);
1637			if (verbose)
1638				fetch_info("If-Modified-Since: %s", timebuf);
1639			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1640		}
1641		/* virtual host */
1642		http_cmd(conn, "Host: %s", host);
1643
1644		/*
1645		 * Proxy authorization: we only send auth after we received
1646		 * a 407 error. We do not first try basic anyway (changed
1647		 * when support was added for digest-auth)
1648		 */
1649		if (purl && proxy_challenges.valid) {
1650			http_auth_params_t aparams;
1651			init_http_auth_params(&aparams);
1652			if (*purl->user || *purl->pwd) {
1653				aparams.user = strdup(purl->user);
1654				aparams.password = strdup(purl->pwd);
1655			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1656				   *p != '\0') {
1657				if (http_authfromenv(p, &aparams) < 0) {
1658					http_seterr(HTTP_NEED_PROXY_AUTH);
1659					goto ouch;
1660				}
1661			} else if (fetch_netrc_auth(purl) == 0) {
1662				aparams.user = strdup(purl->user);
1663				aparams.password = strdup(purl->pwd);
1664			}
1665			http_authorize(conn, "Proxy-Authorization",
1666				       &proxy_challenges, &aparams, url);
1667			clean_http_auth_params(&aparams);
1668		}
1669
1670		/*
1671		 * Server authorization: we never send "a priori"
1672		 * Basic auth, which used to be done if user/pass were
1673		 * set in the url. This would be weird because we'd send the
1674		 * password in the clear even if Digest is finally to be
1675		 * used (it would have made more sense for the
1676		 * pre-digest version to do this when Basic was specified
1677		 * in the environment)
1678		 */
1679		if (server_challenges.valid) {
1680			http_auth_params_t aparams;
1681			init_http_auth_params(&aparams);
1682			if (*url->user || *url->pwd) {
1683				aparams.user = strdup(url->user);
1684				aparams.password = strdup(url->pwd);
1685			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1686				   *p != '\0') {
1687				if (http_authfromenv(p, &aparams) < 0) {
1688					http_seterr(HTTP_NEED_AUTH);
1689					goto ouch;
1690				}
1691			} else if (fetch_netrc_auth(url) == 0) {
1692				aparams.user = strdup(url->user);
1693				aparams.password = strdup(url->pwd);
1694			} else if (fetchAuthMethod &&
1695				   fetchAuthMethod(url) == 0) {
1696				aparams.user = strdup(url->user);
1697				aparams.password = strdup(url->pwd);
1698			} else {
1699				http_seterr(HTTP_NEED_AUTH);
1700				goto ouch;
1701			}
1702			http_authorize(conn, "Authorization",
1703				       &server_challenges, &aparams, url);
1704			clean_http_auth_params(&aparams);
1705		}
1706
1707		/* other headers */
1708		if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1709			if (*p != '\0')
1710				http_cmd(conn, "Accept: %s", p);
1711		} else {
1712			http_cmd(conn, "Accept: */*");
1713		}
1714		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1715			if (strcasecmp(p, "auto") == 0)
1716				http_cmd(conn, "Referer: %s://%s%s",
1717				    url->scheme, host, url->doc);
1718			else
1719				http_cmd(conn, "Referer: %s", p);
1720		}
1721		if ((p = getenv("HTTP_USER_AGENT")) != NULL) {
1722			/* no User-Agent if defined but empty */
1723			if  (*p != '\0')
1724				http_cmd(conn, "User-Agent: %s", p);
1725		} else {
1726			/* default User-Agent */
1727			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER,
1728			    getprogname());
1729		}
1730		if (url->offset > 0)
1731			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1732		http_cmd(conn, "Connection: close");
1733
1734		if (body) {
1735			body_len = strlen(body);
1736			http_cmd(conn, "Content-Length: %zu", body_len);
1737			if (content_type != NULL)
1738				http_cmd(conn, "Content-Type: %s", content_type);
1739		}
1740
1741		http_cmd(conn, "");
1742
1743		if (body)
1744			fetch_write(conn, body, body_len);
1745
1746		/*
1747		 * Force the queued request to be dispatched.  Normally, one
1748		 * would do this with shutdown(2) but squid proxies can be
1749		 * configured to disallow such half-closed connections.  To
1750		 * be compatible with such configurations, fiddle with socket
1751		 * options to force the pending data to be written.
1752		 */
1753		val = 0;
1754		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1755			   sizeof(val));
1756		val = 1;
1757		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1758			   sizeof(val));
1759
1760		/* get reply */
1761		switch (http_get_reply(conn)) {
1762		case HTTP_OK:
1763		case HTTP_PARTIAL:
1764		case HTTP_NOT_MODIFIED:
1765			/* fine */
1766			break;
1767		case HTTP_MOVED_PERM:
1768		case HTTP_MOVED_TEMP:
1769		case HTTP_SEE_OTHER:
1770		case HTTP_USE_PROXY:
1771			/*
1772			 * Not so fine, but we still have to read the
1773			 * headers to get the new location.
1774			 */
1775			break;
1776		case HTTP_NEED_AUTH:
1777			if (server_challenges.valid) {
1778				/*
1779				 * We already sent out authorization code,
1780				 * so there's nothing more we can do.
1781				 */
1782				http_seterr(conn->err);
1783				goto ouch;
1784			}
1785			/* try again, but send the password this time */
1786			if (verbose)
1787				fetch_info("server requires authorization");
1788			break;
1789		case HTTP_NEED_PROXY_AUTH:
1790			if (proxy_challenges.valid) {
1791				/*
1792				 * We already sent our proxy
1793				 * authorization code, so there's
1794				 * nothing more we can do. */
1795				http_seterr(conn->err);
1796				goto ouch;
1797			}
1798			/* try again, but send the password this time */
1799			if (verbose)
1800				fetch_info("proxy requires authorization");
1801			break;
1802		case HTTP_BAD_RANGE:
1803			/*
1804			 * This can happen if we ask for 0 bytes because
1805			 * we already have the whole file.  Consider this
1806			 * a success for now, and check sizes later.
1807			 */
1808			break;
1809		case HTTP_PROTOCOL_ERROR:
1810			/* fall through */
1811		case -1:
1812			fetch_syserr();
1813			goto ouch;
1814		default:
1815			http_seterr(conn->err);
1816			if (!verbose)
1817				goto ouch;
1818			/* fall through so we can get the full error message */
1819		}
1820
1821		/* get headers. http_next_header expects one line readahead */
1822		if (fetch_getln(conn) == -1) {
1823			fetch_syserr();
1824			goto ouch;
1825		}
1826		do {
1827			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1828			case hdr_syserror:
1829				fetch_syserr();
1830				goto ouch;
1831			case hdr_error:
1832				http_seterr(HTTP_PROTOCOL_ERROR);
1833				goto ouch;
1834			case hdr_content_length:
1835				http_parse_length(p, &clength);
1836				break;
1837			case hdr_content_range:
1838				http_parse_range(p, &offset, &length, &size);
1839				break;
1840			case hdr_last_modified:
1841				http_parse_mtime(p, &mtime);
1842				break;
1843			case hdr_location:
1844				if (!HTTP_REDIRECT(conn->err))
1845					break;
1846				/*
1847				 * if the A flag is set, we don't follow
1848				 * temporary redirects.
1849				 */
1850				if (noredirect &&
1851				    conn->err != HTTP_MOVED_PERM &&
1852				    conn->err != HTTP_PERM_REDIRECT &&
1853				    conn->err != HTTP_USE_PROXY) {
1854					n = 1;
1855					break;
1856				}
1857				if (new)
1858					free(new);
1859				if (verbose)
1860					fetch_info("%d redirect to %s", conn->err, p);
1861				if (*p == '/')
1862					/* absolute path */
1863					new = fetchMakeURL(url->scheme, url->host, url->port, p,
1864					    url->user, url->pwd);
1865				else
1866					new = fetchParseURL(p);
1867				if (new == NULL) {
1868					/* XXX should set an error code */
1869					DEBUG(fprintf(stderr, "failed to parse new URL\n"));
1870					goto ouch;
1871				}
1872
1873				/* Only copy credentials if the host matches */
1874				if (!strcmp(new->host, url->host) && !*new->user && !*new->pwd) {
1875					strcpy(new->user, url->user);
1876					strcpy(new->pwd, url->pwd);
1877				}
1878				new->offset = url->offset;
1879				new->length = url->length;
1880				break;
1881			case hdr_transfer_encoding:
1882				/* XXX weak test*/
1883				chunked = (strcasecmp(p, "chunked") == 0);
1884				break;
1885			case hdr_www_authenticate:
1886				if (conn->err != HTTP_NEED_AUTH)
1887					break;
1888				if (http_parse_authenticate(p, &server_challenges) == 0)
1889					++n;
1890				break;
1891			case hdr_proxy_authenticate:
1892				if (conn->err != HTTP_NEED_PROXY_AUTH)
1893					break;
1894				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1895					++n;
1896				break;
1897			case hdr_end:
1898				/* fall through */
1899			case hdr_unknown:
1900				/* ignore */
1901				break;
1902			}
1903		} while (h > hdr_end);
1904
1905		/* we need to provide authentication */
1906		if (conn->err == HTTP_NEED_AUTH ||
1907		    conn->err == HTTP_NEED_PROXY_AUTH) {
1908			e = conn->err;
1909			if ((conn->err == HTTP_NEED_AUTH &&
1910			     !server_challenges.valid) ||
1911			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1912			     !proxy_challenges.valid)) {
1913				/* 401/7 but no www/proxy-authenticate ?? */
1914				DEBUG(fprintf(stderr, "401/7 and no auth header\n"));
1915				goto ouch;
1916			}
1917			fetch_close(conn);
1918			conn = NULL;
1919			continue;
1920		}
1921
1922		/* requested range not satisfiable */
1923		if (conn->err == HTTP_BAD_RANGE) {
1924			if (url->offset == size && url->length == 0) {
1925				/* asked for 0 bytes; fake it */
1926				offset = url->offset;
1927				clength = -1;
1928				conn->err = HTTP_OK;
1929				break;
1930			} else {
1931				http_seterr(conn->err);
1932				goto ouch;
1933			}
1934		}
1935
1936		/* we have a hit or an error */
1937		if (conn->err == HTTP_OK
1938		    || conn->err == HTTP_NOT_MODIFIED
1939		    || conn->err == HTTP_PARTIAL
1940		    || HTTP_ERROR(conn->err))
1941			break;
1942
1943		/* all other cases: we got a redirect */
1944		e = conn->err;
1945		clean_http_auth_challenges(&server_challenges);
1946		fetch_close(conn);
1947		conn = NULL;
1948		if (!new) {
1949			DEBUG(fprintf(stderr, "redirect with no new location\n"));
1950			break;
1951		}
1952		if (url != URL)
1953			fetchFreeURL(url);
1954		url = new;
1955	} while (++i < n);
1956
1957	/* we failed, or ran out of retries */
1958	if (conn == NULL) {
1959		http_seterr(e);
1960		goto ouch;
1961	}
1962
1963	DEBUG(fprintf(stderr, "offset %lld, length %lld,"
1964		  " size %lld, clength %lld\n",
1965		  (long long)offset, (long long)length,
1966		  (long long)size, (long long)clength));
1967
1968	if (conn->err == HTTP_NOT_MODIFIED) {
1969		http_seterr(HTTP_NOT_MODIFIED);
1970		return (NULL);
1971	}
1972
1973	/* check for inconsistencies */
1974	if (clength != -1 && length != -1 && clength != length) {
1975		http_seterr(HTTP_PROTOCOL_ERROR);
1976		goto ouch;
1977	}
1978	if (clength == -1)
1979		clength = length;
1980	if (clength != -1)
1981		length = offset + clength;
1982	if (length != -1 && size != -1 && length != size) {
1983		http_seterr(HTTP_PROTOCOL_ERROR);
1984		goto ouch;
1985	}
1986	if (size == -1)
1987		size = length;
1988
1989	/* fill in stats */
1990	if (us) {
1991		us->size = size;
1992		us->atime = us->mtime = mtime;
1993	}
1994
1995	/* too far? */
1996	if (URL->offset > 0 && offset > URL->offset) {
1997		http_seterr(HTTP_PROTOCOL_ERROR);
1998		goto ouch;
1999	}
2000
2001	/* report back real offset and size */
2002	URL->offset = offset;
2003	URL->length = clength;
2004
2005	/* wrap it up in a FILE */
2006	if ((f = http_funopen(conn, chunked)) == NULL) {
2007		fetch_syserr();
2008		goto ouch;
2009	}
2010
2011	if (url != URL)
2012		fetchFreeURL(url);
2013	if (purl)
2014		fetchFreeURL(purl);
2015
2016	if (HTTP_ERROR(conn->err)) {
2017		http_print_html(stderr, f);
2018		fclose(f);
2019		f = NULL;
2020	}
2021	clean_http_headerbuf(&headerbuf);
2022	clean_http_auth_challenges(&server_challenges);
2023	clean_http_auth_challenges(&proxy_challenges);
2024	return (f);
2025
2026ouch:
2027	if (url != URL)
2028		fetchFreeURL(url);
2029	if (purl)
2030		fetchFreeURL(purl);
2031	if (conn != NULL)
2032		fetch_close(conn);
2033	clean_http_headerbuf(&headerbuf);
2034	clean_http_auth_challenges(&server_challenges);
2035	clean_http_auth_challenges(&proxy_challenges);
2036	return (NULL);
2037}
2038
2039
2040/*****************************************************************************
2041 * Entry points
2042 */
2043
2044/*
2045 * Retrieve and stat a file by HTTP
2046 */
2047FILE *
2048fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
2049{
2050	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
2051}
2052
2053/*
2054 * Retrieve a file by HTTP
2055 */
2056FILE *
2057fetchGetHTTP(struct url *URL, const char *flags)
2058{
2059	return (fetchXGetHTTP(URL, NULL, flags));
2060}
2061
2062/*
2063 * Store a file by HTTP
2064 */
2065FILE *
2066fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2067{
2068	warnx("fetchPutHTTP(): not implemented");
2069	return (NULL);
2070}
2071
2072/*
2073 * Get an HTTP document's metadata
2074 */
2075int
2076fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2077{
2078	FILE *f;
2079
2080	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2081	if (f == NULL)
2082		return (-1);
2083	fclose(f);
2084	return (0);
2085}
2086
2087/*
2088 * List a directory
2089 */
2090struct url_ent *
2091fetchListHTTP(struct url *url __unused, const char *flags __unused)
2092{
2093	warnx("fetchListHTTP(): not implemented");
2094	return (NULL);
2095}
2096
2097FILE *
2098fetchReqHTTP(struct url *URL, const char *method, const char *flags,
2099	const char *content_type, const char *body)
2100{
2101
2102	return (http_request_body(URL, method, NULL, http_get_proxy(URL, flags),
2103	    flags, content_type, body));
2104}
2105