http.c revision 221821 
1/*-
2 * Copyright (c) 2000-2004 Dag-Erling Co�dan 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 221821 2011-05-12 21:18:55Z des $");
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#include <md5.h>
80
81#include <netinet/in.h>
82#include <netinet/tcp.h>
83
84#include "fetch.h"
85#include "common.h"
86#include "httperr.h"
87
88/* Maximum number of redirects to follow */
89#define MAX_REDIRECT 5
90
91/* Symbolic names for reply codes we care about */
92#define HTTP_OK			200
93#define HTTP_PARTIAL		206
94#define HTTP_MOVED_PERM		301
95#define HTTP_MOVED_TEMP		302
96#define HTTP_SEE_OTHER		303
97#define HTTP_NOT_MODIFIED	304
98#define HTTP_TEMP_REDIRECT	307
99#define HTTP_NEED_AUTH		401
100#define HTTP_NEED_PROXY_AUTH	407
101#define HTTP_BAD_RANGE		416
102#define HTTP_PROTOCOL_ERROR	999
103
104#define HTTP_REDIRECT(xyz) ((xyz) == HTTP_MOVED_PERM \
105			    || (xyz) == HTTP_MOVED_TEMP \
106			    || (xyz) == HTTP_TEMP_REDIRECT \
107			    || (xyz) == HTTP_SEE_OTHER)
108
109#define HTTP_ERROR(xyz) ((xyz) > 400 && (xyz) < 599)
110
111
112/*****************************************************************************
113 * I/O functions for decoding chunked streams
114 */
115
116struct httpio
117{
118	conn_t		*conn;		/* connection */
119	int		 chunked;	/* chunked mode */
120	char		*buf;		/* chunk buffer */
121	size_t		 bufsize;	/* size of chunk buffer */
122	ssize_t		 buflen;	/* amount of data currently in buffer */
123	int		 bufpos;	/* current read offset in buffer */
124	int		 eof;		/* end-of-file flag */
125	int		 error;		/* error flag */
126	size_t		 chunksize;	/* remaining size of current chunk */
127#ifndef NDEBUG
128	size_t		 total;
129#endif
130};
131
132/*
133 * Get next chunk header
134 */
135static int
136http_new_chunk(struct httpio *io)
137{
138	char *p;
139
140	if (fetch_getln(io->conn) == -1)
141		return (-1);
142
143	if (io->conn->buflen < 2 || !isxdigit((unsigned char)*io->conn->buf))
144		return (-1);
145
146	for (p = io->conn->buf; *p && !isspace((unsigned char)*p); ++p) {
147		if (*p == ';')
148			break;
149		if (!isxdigit((unsigned char)*p))
150			return (-1);
151		if (isdigit((unsigned char)*p)) {
152			io->chunksize = io->chunksize * 16 +
153			    *p - '0';
154		} else {
155			io->chunksize = io->chunksize * 16 +
156			    10 + tolower((unsigned char)*p) - 'a';
157		}
158	}
159
160#ifndef NDEBUG
161	if (fetchDebug) {
162		io->total += io->chunksize;
163		if (io->chunksize == 0)
164			fprintf(stderr, "%s(): end of last chunk\n", __func__);
165		else
166			fprintf(stderr, "%s(): new chunk: %lu (%lu)\n",
167			    __func__, (unsigned long)io->chunksize,
168			    (unsigned long)io->total);
169	}
170#endif
171
172	return (io->chunksize);
173}
174
175/*
176 * Grow the input buffer to at least len bytes
177 */
178static inline int
179http_growbuf(struct httpio *io, size_t len)
180{
181	char *tmp;
182
183	if (io->bufsize >= len)
184		return (0);
185
186	if ((tmp = realloc(io->buf, len)) == NULL)
187		return (-1);
188	io->buf = tmp;
189	io->bufsize = len;
190	return (0);
191}
192
193/*
194 * Fill the input buffer, do chunk decoding on the fly
195 */
196static int
197http_fillbuf(struct httpio *io, size_t len)
198{
199	if (io->error)
200		return (-1);
201	if (io->eof)
202		return (0);
203
204	if (io->chunked == 0) {
205		if (http_growbuf(io, len) == -1)
206			return (-1);
207		if ((io->buflen = fetch_read(io->conn, io->buf, len)) == -1) {
208			io->error = 1;
209			return (-1);
210		}
211		io->bufpos = 0;
212		return (io->buflen);
213	}
214
215	if (io->chunksize == 0) {
216		switch (http_new_chunk(io)) {
217		case -1:
218			io->error = 1;
219			return (-1);
220		case 0:
221			io->eof = 1;
222			return (0);
223		}
224	}
225
226	if (len > io->chunksize)
227		len = io->chunksize;
228	if (http_growbuf(io, len) == -1)
229		return (-1);
230	if ((io->buflen = fetch_read(io->conn, io->buf, len)) == -1) {
231		io->error = 1;
232		return (-1);
233	}
234	io->chunksize -= io->buflen;
235
236	if (io->chunksize == 0) {
237		char endl[2];
238
239		if (fetch_read(io->conn, endl, 2) != 2 ||
240		    endl[0] != '\r' || endl[1] != '\n')
241			return (-1);
242	}
243
244	io->bufpos = 0;
245
246	return (io->buflen);
247}
248
249/*
250 * Read function
251 */
252static int
253http_readfn(void *v, char *buf, int len)
254{
255	struct httpio *io = (struct httpio *)v;
256	int l, pos;
257
258	if (io->error)
259		return (-1);
260	if (io->eof)
261		return (0);
262
263	for (pos = 0; len > 0; pos += l, len -= l) {
264		/* empty buffer */
265		if (!io->buf || io->bufpos == io->buflen)
266			if (http_fillbuf(io, len) < 1)
267				break;
268		l = io->buflen - io->bufpos;
269		if (len < l)
270			l = len;
271		memcpy(buf + pos, io->buf + io->bufpos, l);
272		io->bufpos += l;
273	}
274
275	if (!pos && io->error)
276		return (-1);
277	return (pos);
278}
279
280/*
281 * Write function
282 */
283static int
284http_writefn(void *v, const char *buf, int len)
285{
286	struct httpio *io = (struct httpio *)v;
287
288	return (fetch_write(io->conn, buf, len));
289}
290
291/*
292 * Close function
293 */
294static int
295http_closefn(void *v)
296{
297	struct httpio *io = (struct httpio *)v;
298	int r;
299
300	r = fetch_close(io->conn);
301	if (io->buf)
302		free(io->buf);
303	free(io);
304	return (r);
305}
306
307/*
308 * Wrap a file descriptor up
309 */
310static FILE *
311http_funopen(conn_t *conn, int chunked)
312{
313	struct httpio *io;
314	FILE *f;
315
316	if ((io = calloc(1, sizeof(*io))) == NULL) {
317		fetch_syserr();
318		return (NULL);
319	}
320	io->conn = conn;
321	io->chunked = chunked;
322	f = funopen(io, http_readfn, http_writefn, NULL, http_closefn);
323	if (f == NULL) {
324		fetch_syserr();
325		free(io);
326		return (NULL);
327	}
328	return (f);
329}
330
331
332/*****************************************************************************
333 * Helper functions for talking to the server and parsing its replies
334 */
335
336/* Header types */
337typedef enum {
338	hdr_syserror = -2,
339	hdr_error = -1,
340	hdr_end = 0,
341	hdr_unknown = 1,
342	hdr_content_length,
343	hdr_content_range,
344	hdr_last_modified,
345	hdr_location,
346	hdr_transfer_encoding,
347	hdr_www_authenticate,
348	hdr_proxy_authenticate,
349} hdr_t;
350
351/* Names of interesting headers */
352static struct {
353	hdr_t		 num;
354	const char	*name;
355} hdr_names[] = {
356	{ hdr_content_length,		"Content-Length" },
357	{ hdr_content_range,		"Content-Range" },
358	{ hdr_last_modified,		"Last-Modified" },
359	{ hdr_location,			"Location" },
360	{ hdr_transfer_encoding,	"Transfer-Encoding" },
361	{ hdr_www_authenticate,		"WWW-Authenticate" },
362	{ hdr_proxy_authenticate,	"Proxy-Authenticate" },
363	{ hdr_unknown,			NULL },
364};
365
366/*
367 * Send a formatted line; optionally echo to terminal
368 */
369static int
370http_cmd(conn_t *conn, const char *fmt, ...)
371{
372	va_list ap;
373	size_t len;
374	char *msg;
375	int r;
376
377	va_start(ap, fmt);
378	len = vasprintf(&msg, fmt, ap);
379	va_end(ap);
380
381	if (msg == NULL) {
382		errno = ENOMEM;
383		fetch_syserr();
384		return (-1);
385	}
386
387	r = fetch_putln(conn, msg, len);
388	free(msg);
389
390	if (r == -1) {
391		fetch_syserr();
392		return (-1);
393	}
394
395	return (0);
396}
397
398/*
399 * Get and parse status line
400 */
401static int
402http_get_reply(conn_t *conn)
403{
404	char *p;
405
406	if (fetch_getln(conn) == -1)
407		return (-1);
408	/*
409	 * A valid status line looks like "HTTP/m.n xyz reason" where m
410	 * and n are the major and minor protocol version numbers and xyz
411	 * is the reply code.
412	 * Unfortunately, there are servers out there (NCSA 1.5.1, to name
413	 * just one) that do not send a version number, so we can't rely
414	 * on finding one, but if we do, insist on it being 1.0 or 1.1.
415	 * We don't care about the reason phrase.
416	 */
417	if (strncmp(conn->buf, "HTTP", 4) != 0)
418		return (HTTP_PROTOCOL_ERROR);
419	p = conn->buf + 4;
420	if (*p == '/') {
421		if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
422			return (HTTP_PROTOCOL_ERROR);
423		p += 4;
424	}
425	if (*p != ' ' ||
426	    !isdigit((unsigned char)p[1]) ||
427	    !isdigit((unsigned char)p[2]) ||
428	    !isdigit((unsigned char)p[3]))
429		return (HTTP_PROTOCOL_ERROR);
430
431	conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
432	return (conn->err);
433}
434
435/*
436 * Check a header; if the type matches the given string, return a pointer
437 * to the beginning of the value.
438 */
439static const char *
440http_match(const char *str, const char *hdr)
441{
442	while (*str && *hdr &&
443	    tolower((unsigned char)*str++) == tolower((unsigned char)*hdr++))
444		/* nothing */;
445	if (*str || *hdr != ':')
446		return (NULL);
447	while (*hdr && isspace((unsigned char)*++hdr))
448		/* nothing */;
449	return (hdr);
450}
451
452
453/*
454 * Get the next header and return the appropriate symbolic code.  We
455 * need to read one line ahead for checking for a continuation line
456 * belonging to the current header (continuation lines start with
457 * white space).
458 *
459 * We get called with a fresh line already in the conn buffer, either
460 * from the previous http_next_header() invocation, or, the first
461 * time, from a fetch_getln() performed by our caller.
462 *
463 * This stops when we encounter an empty line (we dont read beyond the header
464 * area).
465 *
466 * Note that the "headerbuf" is just a place to return the result. Its
467 * contents are not used for the next call. This means that no cleanup
468 * is needed when ie doing another connection, just call the cleanup when
469 * fully done to deallocate memory.
470 */
471
472/* Limit the max number of continuation lines to some reasonable value */
473#define HTTP_MAX_CONT_LINES 10
474
475/* Place into which to build a header from one or several lines */
476typedef struct {
477	char	*buf;		/* buffer */
478	size_t	 bufsize;	/* buffer size */
479	size_t	 buflen;	/* length of buffer contents */
480} http_headerbuf_t;
481
482static void
483init_http_headerbuf(http_headerbuf_t *buf)
484{
485	buf->buf = NULL;
486	buf->bufsize = 0;
487	buf->buflen = 0;
488}
489
490static void
491clean_http_headerbuf(http_headerbuf_t *buf)
492{
493	if (buf->buf)
494		free(buf->buf);
495	init_http_headerbuf(buf);
496}
497
498/* Remove whitespace at the end of the buffer */
499static void
500http_conn_trimright(conn_t *conn)
501{
502	while (conn->buflen &&
503	       isspace((unsigned char)conn->buf[conn->buflen - 1]))
504		conn->buflen--;
505	conn->buf[conn->buflen] = '\0';
506}
507
508static hdr_t
509http_next_header(conn_t *conn, http_headerbuf_t *hbuf, const char **p)
510{
511	unsigned int i, len;
512
513	/*
514	 * Have to do the stripping here because of the first line. So
515	 * it's done twice for the subsequent lines. No big deal
516	 */
517	http_conn_trimright(conn);
518	if (conn->buflen == 0)
519		return (hdr_end);
520
521	/* Copy the line to the headerbuf */
522	if (hbuf->bufsize < conn->buflen + 1) {
523		if ((hbuf->buf = realloc(hbuf->buf, conn->buflen + 1)) == NULL)
524			return (hdr_syserror);
525		hbuf->bufsize = conn->buflen + 1;
526	}
527	strcpy(hbuf->buf, conn->buf);
528	hbuf->buflen = conn->buflen;
529
530	/*
531	 * Fetch possible continuation lines. Stop at 1st non-continuation
532	 * and leave it in the conn buffer
533	 */
534	for (i = 0; i < HTTP_MAX_CONT_LINES; i++) {
535		if (fetch_getln(conn) == -1)
536			return (hdr_syserror);
537
538		/*
539		 * Note: we carry on the idea from the previous version
540		 * that a pure whitespace line is equivalent to an empty
541		 * one (so it's not continuation and will be handled when
542		 * we are called next)
543		 */
544		http_conn_trimright(conn);
545		if (conn->buf[0] != ' ' && conn->buf[0] != "\t"[0])
546			break;
547
548		/* Got a continuation line. Concatenate to previous */
549		len = hbuf->buflen + conn->buflen;
550		if (hbuf->bufsize < len + 1) {
551			len *= 2;
552			if ((hbuf->buf = realloc(hbuf->buf, len + 1)) == NULL)
553				return (hdr_syserror);
554			hbuf->bufsize = len + 1;
555		}
556		strcpy(hbuf->buf + hbuf->buflen, conn->buf);
557		hbuf->buflen += conn->buflen;
558	}
559
560	/*
561	 * We could check for malformed headers but we don't really care.
562	 * A valid header starts with a token immediately followed by a
563	 * colon; a token is any sequence of non-control, non-whitespace
564	 * characters except "()<>@,;:\\\"{}".
565	 */
566	for (i = 0; hdr_names[i].num != hdr_unknown; i++)
567		if ((*p = http_match(hdr_names[i].name, hbuf->buf)) != NULL)
568			return (hdr_names[i].num);
569
570	return (hdr_unknown);
571}
572
573/**************************
574 * [Proxy-]Authenticate header parsing
575 */
576
577/*
578 * Read doublequote-delimited string into output buffer obuf (allocated
579 * by caller, whose responsibility it is to ensure that it's big enough)
580 * cp points to the first char after the initial '"'
581 * Handles \ quoting
582 * Returns pointer to the first char after the terminating double quote, or
583 * NULL for error.
584 */
585static const char *
586http_parse_headerstring(const char *cp, char *obuf)
587{
588	for (;;) {
589		switch (*cp) {
590		case 0: /* Unterminated string */
591			*obuf = 0;
592			return (NULL);
593		case '"': /* Ending quote */
594			*obuf = 0;
595			return (++cp);
596		case '\\':
597			if (*++cp == 0) {
598				*obuf = 0;
599				return (NULL);
600			}
601			/* FALLTHROUGH */
602		default:
603			*obuf++ = *cp++;
604		}
605	}
606}
607
608/* Http auth challenge schemes */
609typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
610
611/* Data holder for a Basic or Digest challenge. */
612typedef struct {
613	http_auth_schemes_t scheme;
614	char	*realm;
615	char	*qop;
616	char	*nonce;
617	char	*opaque;
618	char	*algo;
619	int	 stale;
620	int	 nc; /* Nonce count */
621} http_auth_challenge_t;
622
623static void
624init_http_auth_challenge(http_auth_challenge_t *b)
625{
626	b->scheme = HTTPAS_UNKNOWN;
627	b->realm = b->qop = b->nonce = b->opaque = b->algo = NULL;
628	b->stale = b->nc = 0;
629}
630
631static void
632clean_http_auth_challenge(http_auth_challenge_t *b)
633{
634	if (b->realm)
635		free(b->realm);
636	if (b->qop)
637		free(b->qop);
638	if (b->nonce)
639		free(b->nonce);
640	if (b->opaque)
641		free(b->opaque);
642	if (b->algo)
643		free(b->algo);
644	init_http_auth_challenge(b);
645}
646
647/* Data holder for an array of challenges offered in an http response. */
648#define MAX_CHALLENGES 10
649typedef struct {
650	http_auth_challenge_t *challenges[MAX_CHALLENGES];
651	int	count; /* Number of parsed challenges in the array */
652	int	valid; /* We did parse an authenticate header */
653} http_auth_challenges_t;
654
655static void
656init_http_auth_challenges(http_auth_challenges_t *cs)
657{
658	int i;
659	for (i = 0; i < MAX_CHALLENGES; i++)
660		cs->challenges[i] = NULL;
661	cs->count = cs->valid = 0;
662}
663
664static void
665clean_http_auth_challenges(http_auth_challenges_t *cs)
666{
667	int i;
668	/* We rely on non-zero pointers being allocated, not on the count */
669	for (i = 0; i < MAX_CHALLENGES; i++) {
670		if (cs->challenges[i] != NULL) {
671			clean_http_auth_challenge(cs->challenges[i]);
672			free(cs->challenges[i]);
673		}
674	}
675	init_http_auth_challenges(cs);
676}
677
678/*
679 * Enumeration for lexical elements. Separators will be returned as their own
680 * ascii value
681 */
682typedef enum {HTTPHL_WORD=256, HTTPHL_STRING=257, HTTPHL_END=258,
683	      HTTPHL_ERROR = 259} http_header_lex_t;
684
685/*
686 * Determine what kind of token comes next and return possible value
687 * in buf, which is supposed to have been allocated big enough by
688 * caller. Advance input pointer and return element type.
689 */
690static int
691http_header_lex(const char **cpp, char *buf)
692{
693	size_t l;
694	/* Eat initial whitespace */
695	*cpp += strspn(*cpp, " \t");
696	if (**cpp == 0)
697		return (HTTPHL_END);
698
699	/* Separator ? */
700	if (**cpp == ',' || **cpp == '=')
701		return (*((*cpp)++));
702
703	/* String ? */
704	if (**cpp == '"') {
705		*cpp = http_parse_headerstring(++*cpp, buf);
706		if (*cpp == NULL)
707			return (HTTPHL_ERROR);
708		return (HTTPHL_STRING);
709	}
710
711	/* Read other token, until separator or whitespace */
712	l = strcspn(*cpp, " \t,=");
713	memcpy(buf, *cpp, l);
714	buf[l] = 0;
715	*cpp += l;
716	return (HTTPHL_WORD);
717}
718
719/*
720 * Read challenges from http xxx-authenticate header and accumulate them
721 * in the challenges list structure.
722 *
723 * Headers with multiple challenges are specified by rfc2617, but
724 * servers (ie: squid) often send them in separate headers instead,
725 * which in turn is forbidden by the http spec (multiple headers with
726 * the same name are only allowed for pure comma-separated lists, see
727 * rfc2616 sec 4.2).
728 *
729 * We support both approaches anyway
730 */
731static int
732http_parse_authenticate(const char *cp, http_auth_challenges_t *cs)
733{
734	int ret = -1;
735	http_header_lex_t lex;
736	char *key = malloc(strlen(cp) + 1);
737	char *value = malloc(strlen(cp) + 1);
738	char *buf = malloc(strlen(cp) + 1);
739
740	if (key == NULL || value == NULL || buf == NULL) {
741		fetch_syserr();
742		goto out;
743	}
744
745	/* In any case we've seen the header and we set the valid bit */
746	cs->valid = 1;
747
748	/* Need word first */
749	lex = http_header_lex(&cp, key);
750	if (lex != HTTPHL_WORD)
751		goto out;
752
753	/* Loop on challenges */
754	for (; cs->count < MAX_CHALLENGES; cs->count++) {
755		cs->challenges[cs->count] =
756			malloc(sizeof(http_auth_challenge_t));
757		if (cs->challenges[cs->count] == NULL) {
758			fetch_syserr();
759			goto out;
760		}
761		init_http_auth_challenge(cs->challenges[cs->count]);
762		if (!strcasecmp(key, "basic")) {
763			cs->challenges[cs->count]->scheme = HTTPAS_BASIC;
764		} else if (!strcasecmp(key, "digest")) {
765			cs->challenges[cs->count]->scheme = HTTPAS_DIGEST;
766		} else {
767			cs->challenges[cs->count]->scheme = HTTPAS_UNKNOWN;
768			/*
769			 * Continue parsing as basic or digest may
770			 * follow, and the syntax is the same for
771			 * all. We'll just ignore this one when
772			 * looking at the list
773			 */
774		}
775
776		/* Loop on attributes */
777		for (;;) {
778			/* Key */
779			lex = http_header_lex(&cp, key);
780			if (lex != HTTPHL_WORD)
781				goto out;
782
783			/* Equal sign */
784			lex = http_header_lex(&cp, buf);
785			if (lex != '=')
786				goto out;
787
788			/* Value */
789			lex = http_header_lex(&cp, value);
790			if (lex != HTTPHL_WORD && lex != HTTPHL_STRING)
791				goto out;
792
793			if (!strcasecmp(key, "realm"))
794				cs->challenges[cs->count]->realm =
795					strdup(value);
796			else if (!strcasecmp(key, "qop"))
797				cs->challenges[cs->count]->qop =
798					strdup(value);
799			else if (!strcasecmp(key, "nonce"))
800				cs->challenges[cs->count]->nonce =
801					strdup(value);
802			else if (!strcasecmp(key, "opaque"))
803				cs->challenges[cs->count]->opaque =
804					strdup(value);
805			else if (!strcasecmp(key, "algorithm"))
806				cs->challenges[cs->count]->algo =
807					strdup(value);
808			else if (!strcasecmp(key, "stale"))
809				cs->challenges[cs->count]->stale =
810					strcasecmp(value, "no");
811			/* Else ignore unknown attributes */
812
813			/* Comma or Next challenge or End */
814			lex = http_header_lex(&cp, key);
815			/*
816			 * If we get a word here, this is the beginning of the
817			 * next challenge. Break the attributes loop
818			 */
819			if (lex == HTTPHL_WORD)
820				break;
821
822			if (lex == HTTPHL_END) {
823				/* End while looking for ',' is normal exit */
824				cs->count++;
825				ret = 0;
826				goto out;
827			}
828			/* Anything else is an error */
829			if (lex != ',')
830				goto out;
831
832		} /* End attributes loop */
833	} /* End challenge loop */
834
835	/*
836	 * Challenges max count exceeded. This really can't happen
837	 * with normal data, something's fishy -> error
838	 */
839
840out:
841	if (key)
842		free(key);
843	if (value)
844		free(value);
845	if (buf)
846		free(buf);
847	return (ret);
848}
849
850
851/*
852 * Parse a last-modified header
853 */
854static int
855http_parse_mtime(const char *p, time_t *mtime)
856{
857	char locale[64], *r;
858	struct tm tm;
859
860	strncpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
861	setlocale(LC_TIME, "C");
862	r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
863	/* XXX should add support for date-2 and date-3 */
864	setlocale(LC_TIME, locale);
865	if (r == NULL)
866		return (-1);
867	DEBUG(fprintf(stderr, "last modified: [%04d-%02d-%02d "
868		  "%02d:%02d:%02d]\n",
869		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
870		  tm.tm_hour, tm.tm_min, tm.tm_sec));
871	*mtime = timegm(&tm);
872	return (0);
873}
874
875/*
876 * Parse a content-length header
877 */
878static int
879http_parse_length(const char *p, off_t *length)
880{
881	off_t len;
882
883	for (len = 0; *p && isdigit((unsigned char)*p); ++p)
884		len = len * 10 + (*p - '0');
885	if (*p)
886		return (-1);
887	DEBUG(fprintf(stderr, "content length: [%lld]\n",
888	    (long long)len));
889	*length = len;
890	return (0);
891}
892
893/*
894 * Parse a content-range header
895 */
896static int
897http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
898{
899	off_t first, last, len;
900
901	if (strncasecmp(p, "bytes ", 6) != 0)
902		return (-1);
903	p += 6;
904	if (*p == '*') {
905		first = last = -1;
906		++p;
907	} else {
908		for (first = 0; *p && isdigit((unsigned char)*p); ++p)
909			first = first * 10 + *p - '0';
910		if (*p != '-')
911			return (-1);
912		for (last = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
913			last = last * 10 + *p - '0';
914	}
915	if (first > last || *p != '/')
916		return (-1);
917	for (len = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
918		len = len * 10 + *p - '0';
919	if (*p || len < last - first + 1)
920		return (-1);
921	if (first == -1) {
922		DEBUG(fprintf(stderr, "content range: [*/%lld]\n",
923		    (long long)len));
924		*length = 0;
925	} else {
926		DEBUG(fprintf(stderr, "content range: [%lld-%lld/%lld]\n",
927		    (long long)first, (long long)last, (long long)len));
928		*length = last - first + 1;
929	}
930	*offset = first;
931	*size = len;
932	return (0);
933}
934
935
936/*****************************************************************************
937 * Helper functions for authorization
938 */
939
940/*
941 * Base64 encoding
942 */
943static char *
944http_base64(const char *src)
945{
946	static const char base64[] =
947	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
948	    "abcdefghijklmnopqrstuvwxyz"
949	    "0123456789+/";
950	char *str, *dst;
951	size_t l;
952	int t, r;
953
954	l = strlen(src);
955	if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
956		return (NULL);
957	dst = str;
958	r = 0;
959
960	while (l >= 3) {
961		t = (src[0] << 16) | (src[1] << 8) | src[2];
962		dst[0] = base64[(t >> 18) & 0x3f];
963		dst[1] = base64[(t >> 12) & 0x3f];
964		dst[2] = base64[(t >> 6) & 0x3f];
965		dst[3] = base64[(t >> 0) & 0x3f];
966		src += 3; l -= 3;
967		dst += 4; r += 4;
968	}
969
970	switch (l) {
971	case 2:
972		t = (src[0] << 16) | (src[1] << 8);
973		dst[0] = base64[(t >> 18) & 0x3f];
974		dst[1] = base64[(t >> 12) & 0x3f];
975		dst[2] = base64[(t >> 6) & 0x3f];
976		dst[3] = '=';
977		dst += 4;
978		r += 4;
979		break;
980	case 1:
981		t = src[0] << 16;
982		dst[0] = base64[(t >> 18) & 0x3f];
983		dst[1] = base64[(t >> 12) & 0x3f];
984		dst[2] = dst[3] = '=';
985		dst += 4;
986		r += 4;
987		break;
988	case 0:
989		break;
990	}
991
992	*dst = 0;
993	return (str);
994}
995
996
997/*
998 * Extract authorization parameters from environment value.
999 * The value is like scheme:realm:user:pass
1000 */
1001typedef struct {
1002	char	*scheme;
1003	char	*realm;
1004	char	*user;
1005	char	*password;
1006} http_auth_params_t;
1007
1008static void
1009init_http_auth_params(http_auth_params_t *s)
1010{
1011	s->scheme = s->realm = s->user = s->password = 0;
1012}
1013
1014static void
1015clean_http_auth_params(http_auth_params_t *s)
1016{
1017	if (s->scheme)
1018		free(s->scheme);
1019	if (s->realm)
1020		free(s->realm);
1021	if (s->user)
1022		free(s->user);
1023	if (s->password)
1024		free(s->password);
1025	init_http_auth_params(s);
1026}
1027
1028static int
1029http_authfromenv(const char *p, http_auth_params_t *parms)
1030{
1031	int ret = -1;
1032	char *v, *ve;
1033	char *str = strdup(p);
1034
1035	if (str == NULL) {
1036		fetch_syserr();
1037		return (-1);
1038	}
1039	v = str;
1040
1041	if ((ve = strchr(v, ':')) == NULL)
1042		goto out;
1043
1044	*ve = 0;
1045	if ((parms->scheme = strdup(v)) == NULL) {
1046		fetch_syserr();
1047		goto out;
1048	}
1049	v = ve + 1;
1050
1051	if ((ve = strchr(v, ':')) == NULL)
1052		goto out;
1053
1054	*ve = 0;
1055	if ((parms->realm = strdup(v)) == NULL) {
1056		fetch_syserr();
1057		goto out;
1058	}
1059	v = ve + 1;
1060
1061	if ((ve = strchr(v, ':')) == NULL)
1062		goto out;
1063
1064	*ve = 0;
1065	if ((parms->user = strdup(v)) == NULL) {
1066		fetch_syserr();
1067		goto out;
1068	}
1069	v = ve + 1;
1070
1071
1072	if ((parms->password = strdup(v)) == NULL) {
1073		fetch_syserr();
1074		goto out;
1075	}
1076	ret = 0;
1077out:
1078	if (ret == -1)
1079		clean_http_auth_params(parms);
1080	if (str)
1081		free(str);
1082	return (ret);
1083}
1084
1085
1086/*
1087 * Digest response: the code to compute the digest is taken from the
1088 * sample implementation in RFC2616
1089 */
1090#define IN
1091#define OUT
1092
1093#define HASHLEN 16
1094typedef char HASH[HASHLEN];
1095#define HASHHEXLEN 32
1096typedef char HASHHEX[HASHHEXLEN+1];
1097
1098static const char *hexchars = "0123456789abcdef";
1099static void
1100CvtHex(IN HASH Bin, OUT HASHHEX Hex)
1101{
1102	unsigned short i;
1103	unsigned char j;
1104
1105	for (i = 0; i < HASHLEN; i++) {
1106		j = (Bin[i] >> 4) & 0xf;
1107		Hex[i*2] = hexchars[j];
1108		j = Bin[i] & 0xf;
1109		Hex[i*2+1] = hexchars[j];
1110	};
1111	Hex[HASHHEXLEN] = '\0';
1112};
1113
1114/* calculate H(A1) as per spec */
1115static void
1116DigestCalcHA1(
1117	IN char * pszAlg,
1118	IN char * pszUserName,
1119	IN char * pszRealm,
1120	IN char * pszPassword,
1121	IN char * pszNonce,
1122	IN char * pszCNonce,
1123	OUT HASHHEX SessionKey
1124	)
1125{
1126	MD5_CTX Md5Ctx;
1127	HASH HA1;
1128
1129	MD5Init(&Md5Ctx);
1130	MD5Update(&Md5Ctx, pszUserName, strlen(pszUserName));
1131	MD5Update(&Md5Ctx, ":", 1);
1132	MD5Update(&Md5Ctx, pszRealm, strlen(pszRealm));
1133	MD5Update(&Md5Ctx, ":", 1);
1134	MD5Update(&Md5Ctx, pszPassword, strlen(pszPassword));
1135	MD5Final(HA1, &Md5Ctx);
1136	if (strcasecmp(pszAlg, "md5-sess") == 0) {
1137
1138		MD5Init(&Md5Ctx);
1139		MD5Update(&Md5Ctx, HA1, HASHLEN);
1140		MD5Update(&Md5Ctx, ":", 1);
1141		MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1142		MD5Update(&Md5Ctx, ":", 1);
1143		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1144		MD5Final(HA1, &Md5Ctx);
1145	};
1146	CvtHex(HA1, SessionKey);
1147}
1148
1149/* calculate request-digest/response-digest as per HTTP Digest spec */
1150static void
1151DigestCalcResponse(
1152	IN HASHHEX HA1,           /* H(A1) */
1153	IN char * pszNonce,       /* nonce from server */
1154	IN char * pszNonceCount,  /* 8 hex digits */
1155	IN char * pszCNonce,      /* client nonce */
1156	IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
1157	IN char * pszMethod,      /* method from the request */
1158	IN char * pszDigestUri,   /* requested URL */
1159	IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
1160	OUT HASHHEX Response      /* request-digest or response-digest */
1161	)
1162{
1163/*	DEBUG(fprintf(stderr,
1164		      "Calc: HA1[%s] Nonce[%s] qop[%s] method[%s] URI[%s]\n",
1165		      HA1, pszNonce, pszQop, pszMethod, pszDigestUri));*/
1166	MD5_CTX Md5Ctx;
1167	HASH HA2;
1168	HASH RespHash;
1169	HASHHEX HA2Hex;
1170
1171	// calculate H(A2)
1172	MD5Init(&Md5Ctx);
1173	MD5Update(&Md5Ctx, pszMethod, strlen(pszMethod));
1174	MD5Update(&Md5Ctx, ":", 1);
1175	MD5Update(&Md5Ctx, pszDigestUri, strlen(pszDigestUri));
1176	if (strcasecmp(pszQop, "auth-int") == 0) {
1177		MD5Update(&Md5Ctx, ":", 1);
1178		MD5Update(&Md5Ctx, HEntity, HASHHEXLEN);
1179	};
1180	MD5Final(HA2, &Md5Ctx);
1181	CvtHex(HA2, HA2Hex);
1182
1183	// calculate response
1184	MD5Init(&Md5Ctx);
1185	MD5Update(&Md5Ctx, HA1, HASHHEXLEN);
1186	MD5Update(&Md5Ctx, ":", 1);
1187	MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1188	MD5Update(&Md5Ctx, ":", 1);
1189	if (*pszQop) {
1190		MD5Update(&Md5Ctx, pszNonceCount, strlen(pszNonceCount));
1191		MD5Update(&Md5Ctx, ":", 1);
1192		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1193		MD5Update(&Md5Ctx, ":", 1);
1194		MD5Update(&Md5Ctx, pszQop, strlen(pszQop));
1195		MD5Update(&Md5Ctx, ":", 1);
1196	};
1197	MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
1198	MD5Final(RespHash, &Md5Ctx);
1199	CvtHex(RespHash, Response);
1200}
1201
1202/*
1203 * Generate/Send a Digest authorization header
1204 * This looks like: [Proxy-]Authorization: credentials
1205 *
1206 *  credentials      = "Digest" digest-response
1207 *  digest-response  = 1#( username | realm | nonce | digest-uri
1208 *                      | response | [ algorithm ] | [cnonce] |
1209 *                      [opaque] | [message-qop] |
1210 *                          [nonce-count]  | [auth-param] )
1211 *  username         = "username" "=" username-value
1212 *  username-value   = quoted-string
1213 *  digest-uri       = "uri" "=" digest-uri-value
1214 *  digest-uri-value = request-uri   ; As specified by HTTP/1.1
1215 *  message-qop      = "qop" "=" qop-value
1216 *  cnonce           = "cnonce" "=" cnonce-value
1217 *  cnonce-value     = nonce-value
1218 *  nonce-count      = "nc" "=" nc-value
1219 *  nc-value         = 8LHEX
1220 *  response         = "response" "=" request-digest
1221 *  request-digest = <"> 32LHEX <">
1222 */
1223static int
1224http_digest_auth(conn_t *conn, const char *hdr, http_auth_challenge_t *c,
1225		 http_auth_params_t *parms, struct url *url)
1226{
1227	int r;
1228	char noncecount[10];
1229	char cnonce[40];
1230	char *options = 0;
1231
1232	if (!c->realm || !c->nonce) {
1233		DEBUG(fprintf(stderr, "realm/nonce not set in challenge\n"));
1234		return(-1);
1235	}
1236	if (!c->algo)
1237		c->algo = strdup("");
1238
1239	if (asprintf(&options, "%s%s%s%s",
1240		     *c->algo? ",algorithm=" : "", c->algo,
1241		     c->opaque? ",opaque=" : "", c->opaque?c->opaque:"")== -1)
1242		return (-1);
1243
1244	if (!c->qop) {
1245		c->qop = strdup("");
1246		*noncecount = 0;
1247		*cnonce = 0;
1248	} else {
1249		c->nc++;
1250		sprintf(noncecount, "%08x", c->nc);
1251		/* We don't try very hard with the cnonce ... */
1252		sprintf(cnonce, "%x%lx", getpid(), (unsigned long)time(0));
1253	}
1254
1255	HASHHEX HA1;
1256	DigestCalcHA1(c->algo, parms->user, c->realm,
1257		      parms->password, c->nonce, cnonce, HA1);
1258	DEBUG(fprintf(stderr, "HA1: [%s]\n", HA1));
1259	HASHHEX digest;
1260	DigestCalcResponse(HA1, c->nonce, noncecount, cnonce, c->qop,
1261			   "GET", url->doc, "", digest);
1262
1263	if (c->qop[0]) {
1264		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1265			     "nonce=\"%s\",uri=\"%s\",response=\"%s\","
1266			     "qop=\"auth\", cnonce=\"%s\", nc=%s%s",
1267			     hdr, parms->user, c->realm,
1268			     c->nonce, url->doc, digest,
1269			     cnonce, noncecount, options);
1270	} else {
1271		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1272			     "nonce=\"%s\",uri=\"%s\",response=\"%s\"%s",
1273			     hdr, parms->user, c->realm,
1274			     c->nonce, url->doc, digest, options);
1275	}
1276	if (options)
1277		free(options);
1278	return (r);
1279}
1280
1281/*
1282 * Encode username and password
1283 */
1284static int
1285http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
1286{
1287	char *upw, *auth;
1288	int r;
1289
1290	DEBUG(fprintf(stderr, "basic: usr: [%s]\n", usr));
1291	DEBUG(fprintf(stderr, "basic: pwd: [%s]\n", pwd));
1292	if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
1293		return (-1);
1294	auth = http_base64(upw);
1295	free(upw);
1296	if (auth == NULL)
1297		return (-1);
1298	r = http_cmd(conn, "%s: Basic %s", hdr, auth);
1299	free(auth);
1300	return (r);
1301}
1302
1303/*
1304 * Chose the challenge to answer and call the appropriate routine to
1305 * produce the header.
1306 */
1307static int
1308http_authorize(conn_t *conn, const char *hdr, http_auth_challenges_t *cs,
1309	       http_auth_params_t *parms, struct url *url)
1310{
1311	http_auth_challenge_t *basic = NULL;
1312	http_auth_challenge_t *digest = NULL;
1313	int i;
1314
1315	/* If user or pass are null we're not happy */
1316	if (!parms->user || !parms->password) {
1317		DEBUG(fprintf(stderr, "NULL usr or pass\n"));
1318		return (-1);
1319	}
1320
1321	/* Look for a Digest and a Basic challenge */
1322	for (i = 0; i < cs->count; i++) {
1323		if (cs->challenges[i]->scheme == HTTPAS_BASIC)
1324			basic = cs->challenges[i];
1325		if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1326			digest = cs->challenges[i];
1327	}
1328
1329	/* Error if "Digest" was specified and there is no Digest challenge */
1330	if (!digest && (parms->scheme &&
1331			!strcasecmp(parms->scheme, "digest"))) {
1332		DEBUG(fprintf(stderr,
1333			      "Digest auth in env, not supported by peer\n"));
1334		return (-1);
1335	}
1336	/*
1337	 * If "basic" was specified in the environment, or there is no Digest
1338	 * challenge, do the basic thing. Don't need a challenge for this,
1339	 * so no need to check basic!=NULL
1340	 */
1341	if (!digest || (parms->scheme && !strcasecmp(parms->scheme,"basic")))
1342		return (http_basic_auth(conn,hdr,parms->user,parms->password));
1343
1344	/* Else, prefer digest. We just checked that it's not NULL */
1345	return (http_digest_auth(conn, hdr, digest, parms, url));
1346}
1347
1348/*****************************************************************************
1349 * Helper functions for connecting to a server or proxy
1350 */
1351
1352/*
1353 * Connect to the correct HTTP server or proxy.
1354 */
1355static conn_t *
1356http_connect(struct url *URL, struct url *purl, const char *flags)
1357{
1358	conn_t *conn;
1359	int verbose;
1360	int af, val;
1361
1362#ifdef INET6
1363	af = AF_UNSPEC;
1364#else
1365	af = AF_INET;
1366#endif
1367
1368	verbose = CHECK_FLAG('v');
1369	if (CHECK_FLAG('4'))
1370		af = AF_INET;
1371#ifdef INET6
1372	else if (CHECK_FLAG('6'))
1373		af = AF_INET6;
1374#endif
1375
1376	if (purl && strcasecmp(URL->scheme, SCHEME_HTTPS) != 0) {
1377		URL = purl;
1378	} else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0) {
1379		/* can't talk http to an ftp server */
1380		/* XXX should set an error code */
1381		return (NULL);
1382	}
1383
1384	if ((conn = fetch_connect(URL->host, URL->port, af, verbose)) == NULL)
1385		/* fetch_connect() has already set an error code */
1386		return (NULL);
1387	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1388	    fetch_ssl(conn, verbose) == -1) {
1389		fetch_close(conn);
1390		/* grrr */
1391		errno = EAUTH;
1392		fetch_syserr();
1393		return (NULL);
1394	}
1395
1396	val = 1;
1397	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1398
1399	return (conn);
1400}
1401
1402static struct url *
1403http_get_proxy(struct url * url, const char *flags)
1404{
1405	struct url *purl;
1406	char *p;
1407
1408	if (flags != NULL && strchr(flags, 'd') != NULL)
1409		return (NULL);
1410	if (fetch_no_proxy_match(url->host))
1411		return (NULL);
1412	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1413	    *p && (purl = fetchParseURL(p))) {
1414		if (!*purl->scheme)
1415			strcpy(purl->scheme, SCHEME_HTTP);
1416		if (!purl->port)
1417			purl->port = fetch_default_proxy_port(purl->scheme);
1418		if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1419			return (purl);
1420		fetchFreeURL(purl);
1421	}
1422	return (NULL);
1423}
1424
1425static void
1426http_print_html(FILE *out, FILE *in)
1427{
1428	size_t len;
1429	char *line, *p, *q;
1430	int comment, tag;
1431
1432	comment = tag = 0;
1433	while ((line = fgetln(in, &len)) != NULL) {
1434		while (len && isspace((unsigned char)line[len - 1]))
1435			--len;
1436		for (p = q = line; q < line + len; ++q) {
1437			if (comment && *q == '-') {
1438				if (q + 2 < line + len &&
1439				    strcmp(q, "-->") == 0) {
1440					tag = comment = 0;
1441					q += 2;
1442				}
1443			} else if (tag && !comment && *q == '>') {
1444				p = q + 1;
1445				tag = 0;
1446			} else if (!tag && *q == '<') {
1447				if (q > p)
1448					fwrite(p, q - p, 1, out);
1449				tag = 1;
1450				if (q + 3 < line + len &&
1451				    strcmp(q, "<!--") == 0) {
1452					comment = 1;
1453					q += 3;
1454				}
1455			}
1456		}
1457		if (!tag && q > p)
1458			fwrite(p, q - p, 1, out);
1459		fputc('\n', out);
1460	}
1461}
1462
1463
1464/*****************************************************************************
1465 * Core
1466 */
1467
1468/*
1469 * Send a request and process the reply
1470 *
1471 * XXX This function is way too long, the do..while loop should be split
1472 * XXX off into a separate function.
1473 */
1474FILE *
1475http_request(struct url *URL, const char *op, struct url_stat *us,
1476	struct url *purl, const char *flags)
1477{
1478	char timebuf[80];
1479	char hbuf[MAXHOSTNAMELEN + 7], *host;
1480	conn_t *conn;
1481	struct url *url, *new;
1482	int chunked, direct, ims, noredirect, verbose;
1483	int e, i, n, val;
1484	off_t offset, clength, length, size;
1485	time_t mtime;
1486	const char *p;
1487	FILE *f;
1488	hdr_t h;
1489	struct tm *timestruct;
1490	http_headerbuf_t headerbuf;
1491	http_auth_challenges_t server_challenges;
1492	http_auth_challenges_t proxy_challenges;
1493
1494	/* The following calls don't allocate anything */
1495	init_http_headerbuf(&headerbuf);
1496	init_http_auth_challenges(&server_challenges);
1497	init_http_auth_challenges(&proxy_challenges);
1498
1499	direct = CHECK_FLAG('d');
1500	noredirect = CHECK_FLAG('A');
1501	verbose = CHECK_FLAG('v');
1502	ims = CHECK_FLAG('i');
1503
1504	if (direct && purl) {
1505		fetchFreeURL(purl);
1506		purl = NULL;
1507	}
1508
1509	/* try the provided URL first */
1510	url = URL;
1511
1512	/* if the A flag is set, we only get one try */
1513	n = noredirect ? 1 : MAX_REDIRECT;
1514	i = 0;
1515
1516	e = HTTP_PROTOCOL_ERROR;
1517	do {
1518		new = NULL;
1519		chunked = 0;
1520		offset = 0;
1521		clength = -1;
1522		length = -1;
1523		size = -1;
1524		mtime = 0;
1525
1526		/* check port */
1527		if (!url->port)
1528			url->port = fetch_default_port(url->scheme);
1529
1530		/* were we redirected to an FTP URL? */
1531		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1532			if (strcmp(op, "GET") == 0)
1533				return (ftp_request(url, "RETR", us, purl, flags));
1534			else if (strcmp(op, "HEAD") == 0)
1535				return (ftp_request(url, "STAT", us, purl, flags));
1536		}
1537
1538		/* connect to server or proxy */
1539		if ((conn = http_connect(url, purl, flags)) == NULL)
1540			goto ouch;
1541
1542		host = url->host;
1543#ifdef INET6
1544		if (strchr(url->host, ':')) {
1545			snprintf(hbuf, sizeof(hbuf), "[%s]", url->host);
1546			host = hbuf;
1547		}
1548#endif
1549		if (url->port != fetch_default_port(url->scheme)) {
1550			if (host != hbuf) {
1551				strcpy(hbuf, host);
1552				host = hbuf;
1553			}
1554			snprintf(hbuf + strlen(hbuf),
1555			    sizeof(hbuf) - strlen(hbuf), ":%d", url->port);
1556		}
1557
1558		/* send request */
1559		if (verbose)
1560			fetch_info("requesting %s://%s%s",
1561			    url->scheme, host, url->doc);
1562		if (purl) {
1563			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1564			    op, url->scheme, host, url->doc);
1565		} else {
1566			http_cmd(conn, "%s %s HTTP/1.1",
1567			    op, url->doc);
1568		}
1569
1570		if (ims && url->ims_time) {
1571			timestruct = gmtime((time_t *)&url->ims_time);
1572			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1573			    timestruct);
1574			if (verbose)
1575				fetch_info("If-Modified-Since: %s", timebuf);
1576			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1577		}
1578		/* virtual host */
1579		http_cmd(conn, "Host: %s", host);
1580
1581		/*
1582		 * Proxy authorization: we only send auth after we received
1583		 * a 407 error. We do not first try basic anyway (changed
1584		 * when support was added for digest-auth)
1585		 */
1586		if (purl && proxy_challenges.valid) {
1587			http_auth_params_t aparams;
1588			init_http_auth_params(&aparams);
1589			if (*purl->user || *purl->pwd) {
1590				aparams.user = purl->user ?
1591					strdup(purl->user) : strdup("");
1592				aparams.password = purl->pwd?
1593					strdup(purl->pwd) : strdup("");
1594			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1595				   *p != '\0') {
1596				if (http_authfromenv(p, &aparams) < 0) {
1597					http_seterr(HTTP_NEED_PROXY_AUTH);
1598					goto ouch;
1599				}
1600			}
1601			http_authorize(conn, "Proxy-Authorization",
1602				       &proxy_challenges, &aparams, url);
1603			clean_http_auth_params(&aparams);
1604		}
1605
1606		/*
1607		 * Server authorization: we never send "a priori"
1608		 * Basic auth, which used to be done if user/pass were
1609		 * set in the url. This would be weird because we'd send the
1610		 * password in the clear even if Digest is finally to be
1611		 * used (it would have made more sense for the
1612		 * pre-digest version to do this when Basic was specified
1613		 * in the environment)
1614		 */
1615		if (server_challenges.valid) {
1616			http_auth_params_t aparams;
1617			init_http_auth_params(&aparams);
1618			if (*url->user || *url->pwd) {
1619				aparams.user = url->user ?
1620					strdup(url->user) : strdup("");
1621				aparams.password = url->pwd ?
1622					strdup(url->pwd) : strdup("");
1623			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1624				   *p != '\0') {
1625				if (http_authfromenv(p, &aparams) < 0) {
1626					http_seterr(HTTP_NEED_AUTH);
1627					goto ouch;
1628				}
1629			} else if (fetchAuthMethod &&
1630				   fetchAuthMethod(url) == 0) {
1631				aparams.user = url->user ?
1632					strdup(url->user) : strdup("");
1633				aparams.password = url->pwd ?
1634					strdup(url->pwd) : strdup("");
1635			} else {
1636				http_seterr(HTTP_NEED_AUTH);
1637				goto ouch;
1638			}
1639			http_authorize(conn, "Authorization",
1640				       &server_challenges, &aparams, url);
1641			clean_http_auth_params(&aparams);
1642		}
1643
1644		/* other headers */
1645		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1646			if (strcasecmp(p, "auto") == 0)
1647				http_cmd(conn, "Referer: %s://%s%s",
1648				    url->scheme, host, url->doc);
1649			else
1650				http_cmd(conn, "Referer: %s", p);
1651		}
1652		if ((p = getenv("HTTP_USER_AGENT")) != NULL && *p != '\0')
1653			http_cmd(conn, "User-Agent: %s", p);
1654		else
1655			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER, getprogname());
1656		if (url->offset > 0)
1657			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1658		http_cmd(conn, "Connection: close");
1659		http_cmd(conn, "");
1660
1661		/*
1662		 * Force the queued request to be dispatched.  Normally, one
1663		 * would do this with shutdown(2) but squid proxies can be
1664		 * configured to disallow such half-closed connections.  To
1665		 * be compatible with such configurations, fiddle with socket
1666		 * options to force the pending data to be written.
1667		 */
1668		val = 0;
1669		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1670			   sizeof(val));
1671		val = 1;
1672		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1673			   sizeof(val));
1674
1675		/* get reply */
1676		switch (http_get_reply(conn)) {
1677		case HTTP_OK:
1678		case HTTP_PARTIAL:
1679		case HTTP_NOT_MODIFIED:
1680			/* fine */
1681			break;
1682		case HTTP_MOVED_PERM:
1683		case HTTP_MOVED_TEMP:
1684		case HTTP_SEE_OTHER:
1685			/*
1686			 * Not so fine, but we still have to read the
1687			 * headers to get the new location.
1688			 */
1689			break;
1690		case HTTP_NEED_AUTH:
1691			if (server_challenges.valid) {
1692				/*
1693				 * We already sent out authorization code,
1694				 * so there's nothing more we can do.
1695				 */
1696				http_seterr(conn->err);
1697				goto ouch;
1698			}
1699			/* try again, but send the password this time */
1700			if (verbose)
1701				fetch_info("server requires authorization");
1702			break;
1703		case HTTP_NEED_PROXY_AUTH:
1704			if (proxy_challenges.valid) {
1705				/*
1706				 * We already sent our proxy
1707				 * authorization code, so there's
1708				 * nothing more we can do. */
1709				http_seterr(conn->err);
1710				goto ouch;
1711			}
1712			/* try again, but send the password this time */
1713			if (verbose)
1714				fetch_info("proxy requires authorization");
1715			break;
1716		case HTTP_BAD_RANGE:
1717			/*
1718			 * This can happen if we ask for 0 bytes because
1719			 * we already have the whole file.  Consider this
1720			 * a success for now, and check sizes later.
1721			 */
1722			break;
1723		case HTTP_PROTOCOL_ERROR:
1724			/* fall through */
1725		case -1:
1726			fetch_syserr();
1727			goto ouch;
1728		default:
1729			http_seterr(conn->err);
1730			if (!verbose)
1731				goto ouch;
1732			/* fall through so we can get the full error message */
1733		}
1734
1735		/* get headers. http_next_header expects one line readahead */
1736		if (fetch_getln(conn) == -1) {
1737		    fetch_syserr();
1738		    goto ouch;
1739		}
1740		do {
1741		    switch ((h = http_next_header(conn, &headerbuf, &p))) {
1742			case hdr_syserror:
1743				fetch_syserr();
1744				goto ouch;
1745			case hdr_error:
1746				http_seterr(HTTP_PROTOCOL_ERROR);
1747				goto ouch;
1748			case hdr_content_length:
1749				http_parse_length(p, &clength);
1750				break;
1751			case hdr_content_range:
1752				http_parse_range(p, &offset, &length, &size);
1753				break;
1754			case hdr_last_modified:
1755				http_parse_mtime(p, &mtime);
1756				break;
1757			case hdr_location:
1758				if (!HTTP_REDIRECT(conn->err))
1759					break;
1760				if (new)
1761					free(new);
1762				if (verbose)
1763					fetch_info("%d redirect to %s", conn->err, p);
1764				if (*p == '/')
1765					/* absolute path */
1766					new = fetchMakeURL(url->scheme, url->host, url->port, p,
1767					    url->user, url->pwd);
1768				else
1769					new = fetchParseURL(p);
1770				if (new == NULL) {
1771					/* XXX should set an error code */
1772					DEBUG(fprintf(stderr, "failed to parse new URL\n"));
1773					goto ouch;
1774				}
1775				if (!*new->user && !*new->pwd) {
1776					strcpy(new->user, url->user);
1777					strcpy(new->pwd, url->pwd);
1778				}
1779				new->offset = url->offset;
1780				new->length = url->length;
1781				break;
1782			case hdr_transfer_encoding:
1783				/* XXX weak test*/
1784				chunked = (strcasecmp(p, "chunked") == 0);
1785				break;
1786			case hdr_www_authenticate:
1787				if (conn->err != HTTP_NEED_AUTH)
1788					break;
1789				if (http_parse_authenticate(p, &server_challenges) == 0)
1790					++n;
1791				break;
1792			case hdr_proxy_authenticate:
1793				if (conn->err != HTTP_NEED_PROXY_AUTH)
1794					break;
1795				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1796					++n;
1797				break;
1798			case hdr_end:
1799				/* fall through */
1800			case hdr_unknown:
1801				/* ignore */
1802				break;
1803			}
1804		} while (h > hdr_end);
1805
1806		/* we need to provide authentication */
1807		if (conn->err == HTTP_NEED_AUTH ||
1808		    conn->err == HTTP_NEED_PROXY_AUTH) {
1809			e = conn->err;
1810			if ((conn->err == HTTP_NEED_AUTH &&
1811			     !server_challenges.valid) ||
1812			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1813			     !proxy_challenges.valid)) {
1814				/* 401/7 but no www/proxy-authenticate ?? */
1815				DEBUG(fprintf(stderr, "401/7 and no auth header\n"));
1816				goto ouch;
1817			}
1818			fetch_close(conn);
1819			conn = NULL;
1820			continue;
1821		}
1822
1823		/* requested range not satisfiable */
1824		if (conn->err == HTTP_BAD_RANGE) {
1825			if (url->offset == size && url->length == 0) {
1826				/* asked for 0 bytes; fake it */
1827				offset = url->offset;
1828				clength = -1;
1829				conn->err = HTTP_OK;
1830				break;
1831			} else {
1832				http_seterr(conn->err);
1833				goto ouch;
1834			}
1835		}
1836
1837		/* we have a hit or an error */
1838		if (conn->err == HTTP_OK
1839		    || conn->err == HTTP_NOT_MODIFIED
1840		    || conn->err == HTTP_PARTIAL
1841		    || HTTP_ERROR(conn->err))
1842			break;
1843
1844		/* all other cases: we got a redirect */
1845		e = conn->err;
1846		clean_http_auth_challenges(&server_challenges);
1847		fetch_close(conn);
1848		conn = NULL;
1849		if (!new) {
1850			DEBUG(fprintf(stderr, "redirect with no new location\n"));
1851			break;
1852		}
1853		if (url != URL)
1854			fetchFreeURL(url);
1855		url = new;
1856	} while (++i < n);
1857
1858	/* we failed, or ran out of retries */
1859	if (conn == NULL) {
1860		http_seterr(e);
1861		goto ouch;
1862	}
1863
1864	DEBUG(fprintf(stderr, "offset %lld, length %lld,"
1865		  " size %lld, clength %lld\n",
1866		  (long long)offset, (long long)length,
1867		  (long long)size, (long long)clength));
1868
1869	if (conn->err == HTTP_NOT_MODIFIED) {
1870		http_seterr(HTTP_NOT_MODIFIED);
1871		return (NULL);
1872	}
1873
1874	/* check for inconsistencies */
1875	if (clength != -1 && length != -1 && clength != length) {
1876		http_seterr(HTTP_PROTOCOL_ERROR);
1877		goto ouch;
1878	}
1879	if (clength == -1)
1880		clength = length;
1881	if (clength != -1)
1882		length = offset + clength;
1883	if (length != -1 && size != -1 && length != size) {
1884		http_seterr(HTTP_PROTOCOL_ERROR);
1885		goto ouch;
1886	}
1887	if (size == -1)
1888		size = length;
1889
1890	/* fill in stats */
1891	if (us) {
1892		us->size = size;
1893		us->atime = us->mtime = mtime;
1894	}
1895
1896	/* too far? */
1897	if (URL->offset > 0 && offset > URL->offset) {
1898		http_seterr(HTTP_PROTOCOL_ERROR);
1899		goto ouch;
1900	}
1901
1902	/* report back real offset and size */
1903	URL->offset = offset;
1904	URL->length = clength;
1905
1906	/* wrap it up in a FILE */
1907	if ((f = http_funopen(conn, chunked)) == NULL) {
1908		fetch_syserr();
1909		goto ouch;
1910	}
1911
1912	if (url != URL)
1913		fetchFreeURL(url);
1914	if (purl)
1915		fetchFreeURL(purl);
1916
1917	if (HTTP_ERROR(conn->err)) {
1918		http_print_html(stderr, f);
1919		fclose(f);
1920		f = NULL;
1921	}
1922	clean_http_headerbuf(&headerbuf);
1923	clean_http_auth_challenges(&server_challenges);
1924	clean_http_auth_challenges(&proxy_challenges);
1925	return (f);
1926
1927ouch:
1928	if (url != URL)
1929		fetchFreeURL(url);
1930	if (purl)
1931		fetchFreeURL(purl);
1932	if (conn != NULL)
1933		fetch_close(conn);
1934	clean_http_headerbuf(&headerbuf);
1935	clean_http_auth_challenges(&server_challenges);
1936	clean_http_auth_challenges(&proxy_challenges);
1937	return (NULL);
1938}
1939
1940
1941/*****************************************************************************
1942 * Entry points
1943 */
1944
1945/*
1946 * Retrieve and stat a file by HTTP
1947 */
1948FILE *
1949fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
1950{
1951	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
1952}
1953
1954/*
1955 * Retrieve a file by HTTP
1956 */
1957FILE *
1958fetchGetHTTP(struct url *URL, const char *flags)
1959{
1960	return (fetchXGetHTTP(URL, NULL, flags));
1961}
1962
1963/*
1964 * Store a file by HTTP
1965 */
1966FILE *
1967fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
1968{
1969	warnx("fetchPutHTTP(): not implemented");
1970	return (NULL);
1971}
1972
1973/*
1974 * Get an HTTP document's metadata
1975 */
1976int
1977fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
1978{
1979	FILE *f;
1980
1981	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
1982	if (f == NULL)
1983		return (-1);
1984	fclose(f);
1985	return (0);
1986}
1987
1988/*
1989 * List a directory
1990 */
1991struct url_ent *
1992fetchListHTTP(struct url *url __unused, const char *flags __unused)
1993{
1994	warnx("fetchListHTTP(): not implemented");
1995	return (NULL);
1996}
1997