http.c revision 267127 
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 267127 2014-06-05 20:27:16Z 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
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 = 0;
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 = 0;
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 *basic = NULL;
1334	http_auth_challenge_t *digest = NULL;
1335	int i;
1336
1337	/* If user or pass are null we're not happy */
1338	if (!parms->user || !parms->password) {
1339		DEBUG(fprintf(stderr, "NULL usr or pass\n"));
1340		return (-1);
1341	}
1342
1343	/* Look for a Digest and a Basic challenge */
1344	for (i = 0; i < cs->count; i++) {
1345		if (cs->challenges[i]->scheme == HTTPAS_BASIC)
1346			basic = cs->challenges[i];
1347		if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1348			digest = cs->challenges[i];
1349	}
1350
1351	/* Error if "Digest" was specified and there is no Digest challenge */
1352	if (!digest && (parms->scheme &&
1353			!strcasecmp(parms->scheme, "digest"))) {
1354		DEBUG(fprintf(stderr,
1355			      "Digest auth in env, not supported by peer\n"));
1356		return (-1);
1357	}
1358	/*
1359	 * If "basic" was specified in the environment, or there is no Digest
1360	 * challenge, do the basic thing. Don't need a challenge for this,
1361	 * so no need to check basic!=NULL
1362	 */
1363	if (!digest || (parms->scheme && !strcasecmp(parms->scheme,"basic")))
1364		return (http_basic_auth(conn,hdr,parms->user,parms->password));
1365
1366	/* Else, prefer digest. We just checked that it's not NULL */
1367	return (http_digest_auth(conn, hdr, digest, parms, url));
1368}
1369
1370/*****************************************************************************
1371 * Helper functions for connecting to a server or proxy
1372 */
1373
1374/*
1375 * Connect to the correct HTTP server or proxy.
1376 */
1377static conn_t *
1378http_connect(struct url *URL, struct url *purl, const char *flags)
1379{
1380	struct url *curl;
1381	conn_t *conn;
1382	int verbose;
1383	int af, val;
1384
1385#ifdef INET6
1386	af = AF_UNSPEC;
1387#else
1388	af = AF_INET;
1389#endif
1390
1391	verbose = CHECK_FLAG('v');
1392	if (CHECK_FLAG('4'))
1393		af = AF_INET;
1394#ifdef INET6
1395	else if (CHECK_FLAG('6'))
1396		af = AF_INET6;
1397#endif
1398
1399	curl = (purl != NULL) ? purl : URL;
1400
1401	if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1402		/* fetch_connect() has already set an error code */
1403		return (NULL);
1404	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1405		http_cmd(conn, "CONNECT %s:%d HTTP/1.1",
1406		    URL->host, URL->port);
1407		http_cmd(conn, "Host: %s:%d",
1408		    URL->host, URL->port);
1409		http_cmd(conn, "");
1410		if (http_get_reply(conn) != HTTP_OK) {
1411			fetch_close(conn);
1412			return (NULL);
1413		}
1414		http_get_reply(conn);
1415	}
1416	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1417	    fetch_ssl(conn, URL, verbose) == -1) {
1418		fetch_close(conn);
1419		/* grrr */
1420		errno = EAUTH;
1421		fetch_syserr();
1422		return (NULL);
1423	}
1424
1425	val = 1;
1426	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1427
1428	return (conn);
1429}
1430
1431static struct url *
1432http_get_proxy(struct url * url, const char *flags)
1433{
1434	struct url *purl;
1435	char *p;
1436
1437	if (flags != NULL && strchr(flags, 'd') != NULL)
1438		return (NULL);
1439	if (fetch_no_proxy_match(url->host))
1440		return (NULL);
1441	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1442	    *p && (purl = fetchParseURL(p))) {
1443		if (!*purl->scheme)
1444			strcpy(purl->scheme, SCHEME_HTTP);
1445		if (!purl->port)
1446			purl->port = fetch_default_proxy_port(purl->scheme);
1447		if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1448			return (purl);
1449		fetchFreeURL(purl);
1450	}
1451	return (NULL);
1452}
1453
1454static void
1455http_print_html(FILE *out, FILE *in)
1456{
1457	size_t len;
1458	char *line, *p, *q;
1459	int comment, tag;
1460
1461	comment = tag = 0;
1462	while ((line = fgetln(in, &len)) != NULL) {
1463		while (len && isspace((unsigned char)line[len - 1]))
1464			--len;
1465		for (p = q = line; q < line + len; ++q) {
1466			if (comment && *q == '-') {
1467				if (q + 2 < line + len &&
1468				    strcmp(q, "-->") == 0) {
1469					tag = comment = 0;
1470					q += 2;
1471				}
1472			} else if (tag && !comment && *q == '>') {
1473				p = q + 1;
1474				tag = 0;
1475			} else if (!tag && *q == '<') {
1476				if (q > p)
1477					fwrite(p, q - p, 1, out);
1478				tag = 1;
1479				if (q + 3 < line + len &&
1480				    strcmp(q, "<!--") == 0) {
1481					comment = 1;
1482					q += 3;
1483				}
1484			}
1485		}
1486		if (!tag && q > p)
1487			fwrite(p, q - p, 1, out);
1488		fputc('\n', out);
1489	}
1490}
1491
1492
1493/*****************************************************************************
1494 * Core
1495 */
1496
1497/*
1498 * Send a request and process the reply
1499 *
1500 * XXX This function is way too long, the do..while loop should be split
1501 * XXX off into a separate function.
1502 */
1503FILE *
1504http_request(struct url *URL, const char *op, struct url_stat *us,
1505	struct url *purl, const char *flags)
1506{
1507	char timebuf[80];
1508	char hbuf[MAXHOSTNAMELEN + 7], *host;
1509	conn_t *conn;
1510	struct url *url, *new;
1511	int chunked, direct, ims, noredirect, verbose;
1512	int e, i, n, val;
1513	off_t offset, clength, length, size;
1514	time_t mtime;
1515	const char *p;
1516	FILE *f;
1517	hdr_t h;
1518	struct tm *timestruct;
1519	http_headerbuf_t headerbuf;
1520	http_auth_challenges_t server_challenges;
1521	http_auth_challenges_t proxy_challenges;
1522
1523	/* The following calls don't allocate anything */
1524	init_http_headerbuf(&headerbuf);
1525	init_http_auth_challenges(&server_challenges);
1526	init_http_auth_challenges(&proxy_challenges);
1527
1528	direct = CHECK_FLAG('d');
1529	noredirect = CHECK_FLAG('A');
1530	verbose = CHECK_FLAG('v');
1531	ims = CHECK_FLAG('i');
1532
1533	if (direct && purl) {
1534		fetchFreeURL(purl);
1535		purl = NULL;
1536	}
1537
1538	/* try the provided URL first */
1539	url = URL;
1540
1541	n = MAX_REDIRECT;
1542	i = 0;
1543
1544	e = HTTP_PROTOCOL_ERROR;
1545	do {
1546		new = NULL;
1547		chunked = 0;
1548		offset = 0;
1549		clength = -1;
1550		length = -1;
1551		size = -1;
1552		mtime = 0;
1553
1554		/* check port */
1555		if (!url->port)
1556			url->port = fetch_default_port(url->scheme);
1557
1558		/* were we redirected to an FTP URL? */
1559		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1560			if (strcmp(op, "GET") == 0)
1561				return (ftp_request(url, "RETR", us, purl, flags));
1562			else if (strcmp(op, "HEAD") == 0)
1563				return (ftp_request(url, "STAT", us, purl, flags));
1564		}
1565
1566		/* connect to server or proxy */
1567		if ((conn = http_connect(url, purl, flags)) == NULL)
1568			goto ouch;
1569
1570		host = url->host;
1571#ifdef INET6
1572		if (strchr(url->host, ':')) {
1573			snprintf(hbuf, sizeof(hbuf), "[%s]", url->host);
1574			host = hbuf;
1575		}
1576#endif
1577		if (url->port != fetch_default_port(url->scheme)) {
1578			if (host != hbuf) {
1579				strcpy(hbuf, host);
1580				host = hbuf;
1581			}
1582			snprintf(hbuf + strlen(hbuf),
1583			    sizeof(hbuf) - strlen(hbuf), ":%d", url->port);
1584		}
1585
1586		/* send request */
1587		if (verbose)
1588			fetch_info("requesting %s://%s%s",
1589			    url->scheme, host, url->doc);
1590		if (purl && strcasecmp(URL->scheme, SCHEME_HTTPS) != 0) {
1591			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1592			    op, url->scheme, host, url->doc);
1593		} else {
1594			http_cmd(conn, "%s %s HTTP/1.1",
1595			    op, url->doc);
1596		}
1597
1598		if (ims && url->ims_time) {
1599			timestruct = gmtime((time_t *)&url->ims_time);
1600			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1601			    timestruct);
1602			if (verbose)
1603				fetch_info("If-Modified-Since: %s", timebuf);
1604			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1605		}
1606		/* virtual host */
1607		http_cmd(conn, "Host: %s", host);
1608
1609		/*
1610		 * Proxy authorization: we only send auth after we received
1611		 * a 407 error. We do not first try basic anyway (changed
1612		 * when support was added for digest-auth)
1613		 */
1614		if (purl && proxy_challenges.valid) {
1615			http_auth_params_t aparams;
1616			init_http_auth_params(&aparams);
1617			if (*purl->user || *purl->pwd) {
1618				aparams.user = purl->user ?
1619					strdup(purl->user) : strdup("");
1620				aparams.password = purl->pwd?
1621					strdup(purl->pwd) : strdup("");
1622			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1623				   *p != '\0') {
1624				if (http_authfromenv(p, &aparams) < 0) {
1625					http_seterr(HTTP_NEED_PROXY_AUTH);
1626					goto ouch;
1627				}
1628			}
1629			http_authorize(conn, "Proxy-Authorization",
1630				       &proxy_challenges, &aparams, url);
1631			clean_http_auth_params(&aparams);
1632		}
1633
1634		/*
1635		 * Server authorization: we never send "a priori"
1636		 * Basic auth, which used to be done if user/pass were
1637		 * set in the url. This would be weird because we'd send the
1638		 * password in the clear even if Digest is finally to be
1639		 * used (it would have made more sense for the
1640		 * pre-digest version to do this when Basic was specified
1641		 * in the environment)
1642		 */
1643		if (server_challenges.valid) {
1644			http_auth_params_t aparams;
1645			init_http_auth_params(&aparams);
1646			if (*url->user || *url->pwd) {
1647				aparams.user = url->user ?
1648					strdup(url->user) : strdup("");
1649				aparams.password = url->pwd ?
1650					strdup(url->pwd) : strdup("");
1651			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1652				   *p != '\0') {
1653				if (http_authfromenv(p, &aparams) < 0) {
1654					http_seterr(HTTP_NEED_AUTH);
1655					goto ouch;
1656				}
1657			} else if (fetchAuthMethod &&
1658				   fetchAuthMethod(url) == 0) {
1659				aparams.user = url->user ?
1660					strdup(url->user) : strdup("");
1661				aparams.password = url->pwd ?
1662					strdup(url->pwd) : strdup("");
1663			} else {
1664				http_seterr(HTTP_NEED_AUTH);
1665				goto ouch;
1666			}
1667			http_authorize(conn, "Authorization",
1668				       &server_challenges, &aparams, url);
1669			clean_http_auth_params(&aparams);
1670		}
1671
1672		/* other headers */
1673		if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1674			if (*p != '\0')
1675				http_cmd(conn, "Accept: %s", p);
1676		} else {
1677			http_cmd(conn, "Accept: */*");
1678		}
1679		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1680			if (strcasecmp(p, "auto") == 0)
1681				http_cmd(conn, "Referer: %s://%s%s",
1682				    url->scheme, host, url->doc);
1683			else
1684				http_cmd(conn, "Referer: %s", p);
1685		}
1686		if ((p = getenv("HTTP_USER_AGENT")) != NULL) {
1687			/* no User-Agent if defined but empty */
1688			if  (*p != '\0')
1689				http_cmd(conn, "User-Agent: %s", p);
1690		} else {
1691			/* default User-Agent */
1692			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER,
1693			    getprogname());
1694		}
1695		if (url->offset > 0)
1696			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1697		http_cmd(conn, "Connection: close");
1698		http_cmd(conn, "");
1699
1700		/*
1701		 * Force the queued request to be dispatched.  Normally, one
1702		 * would do this with shutdown(2) but squid proxies can be
1703		 * configured to disallow such half-closed connections.  To
1704		 * be compatible with such configurations, fiddle with socket
1705		 * options to force the pending data to be written.
1706		 */
1707		val = 0;
1708		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1709			   sizeof(val));
1710		val = 1;
1711		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1712			   sizeof(val));
1713
1714		/* get reply */
1715		switch (http_get_reply(conn)) {
1716		case HTTP_OK:
1717		case HTTP_PARTIAL:
1718		case HTTP_NOT_MODIFIED:
1719			/* fine */
1720			break;
1721		case HTTP_MOVED_PERM:
1722		case HTTP_MOVED_TEMP:
1723		case HTTP_SEE_OTHER:
1724		case HTTP_USE_PROXY:
1725			/*
1726			 * Not so fine, but we still have to read the
1727			 * headers to get the new location.
1728			 */
1729			break;
1730		case HTTP_NEED_AUTH:
1731			if (server_challenges.valid) {
1732				/*
1733				 * We already sent out authorization code,
1734				 * so there's nothing more we can do.
1735				 */
1736				http_seterr(conn->err);
1737				goto ouch;
1738			}
1739			/* try again, but send the password this time */
1740			if (verbose)
1741				fetch_info("server requires authorization");
1742			break;
1743		case HTTP_NEED_PROXY_AUTH:
1744			if (proxy_challenges.valid) {
1745				/*
1746				 * We already sent our proxy
1747				 * authorization code, so there's
1748				 * nothing more we can do. */
1749				http_seterr(conn->err);
1750				goto ouch;
1751			}
1752			/* try again, but send the password this time */
1753			if (verbose)
1754				fetch_info("proxy requires authorization");
1755			break;
1756		case HTTP_BAD_RANGE:
1757			/*
1758			 * This can happen if we ask for 0 bytes because
1759			 * we already have the whole file.  Consider this
1760			 * a success for now, and check sizes later.
1761			 */
1762			break;
1763		case HTTP_PROTOCOL_ERROR:
1764			/* fall through */
1765		case -1:
1766			fetch_syserr();
1767			goto ouch;
1768		default:
1769			http_seterr(conn->err);
1770			if (!verbose)
1771				goto ouch;
1772			/* fall through so we can get the full error message */
1773		}
1774
1775		/* get headers. http_next_header expects one line readahead */
1776		if (fetch_getln(conn) == -1) {
1777			fetch_syserr();
1778			goto ouch;
1779		}
1780		do {
1781			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1782			case hdr_syserror:
1783				fetch_syserr();
1784				goto ouch;
1785			case hdr_error:
1786				http_seterr(HTTP_PROTOCOL_ERROR);
1787				goto ouch;
1788			case hdr_content_length:
1789				http_parse_length(p, &clength);
1790				break;
1791			case hdr_content_range:
1792				http_parse_range(p, &offset, &length, &size);
1793				break;
1794			case hdr_last_modified:
1795				http_parse_mtime(p, &mtime);
1796				break;
1797			case hdr_location:
1798				if (!HTTP_REDIRECT(conn->err))
1799					break;
1800				/*
1801				 * if the A flag is set, we don't follow
1802				 * temporary redirects.
1803				 */
1804				if (noredirect &&
1805				    conn->err != HTTP_MOVED_PERM &&
1806				    conn->err != HTTP_PERM_REDIRECT &&
1807				    conn->err != HTTP_USE_PROXY) {
1808					n = 1;
1809					break;
1810				}
1811				if (new)
1812					free(new);
1813				if (verbose)
1814					fetch_info("%d redirect to %s", conn->err, p);
1815				if (*p == '/')
1816					/* absolute path */
1817					new = fetchMakeURL(url->scheme, url->host, url->port, p,
1818					    url->user, url->pwd);
1819				else
1820					new = fetchParseURL(p);
1821				if (new == NULL) {
1822					/* XXX should set an error code */
1823					DEBUG(fprintf(stderr, "failed to parse new URL\n"));
1824					goto ouch;
1825				}
1826
1827				/* Only copy credentials if the host matches */
1828				if (!strcmp(new->host, url->host) && !*new->user && !*new->pwd) {
1829					strcpy(new->user, url->user);
1830					strcpy(new->pwd, url->pwd);
1831				}
1832				new->offset = url->offset;
1833				new->length = url->length;
1834				break;
1835			case hdr_transfer_encoding:
1836				/* XXX weak test*/
1837				chunked = (strcasecmp(p, "chunked") == 0);
1838				break;
1839			case hdr_www_authenticate:
1840				if (conn->err != HTTP_NEED_AUTH)
1841					break;
1842				if (http_parse_authenticate(p, &server_challenges) == 0)
1843					++n;
1844				break;
1845			case hdr_proxy_authenticate:
1846				if (conn->err != HTTP_NEED_PROXY_AUTH)
1847					break;
1848				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1849					++n;
1850				break;
1851			case hdr_end:
1852				/* fall through */
1853			case hdr_unknown:
1854				/* ignore */
1855				break;
1856			}
1857		} while (h > hdr_end);
1858
1859		/* we need to provide authentication */
1860		if (conn->err == HTTP_NEED_AUTH ||
1861		    conn->err == HTTP_NEED_PROXY_AUTH) {
1862			e = conn->err;
1863			if ((conn->err == HTTP_NEED_AUTH &&
1864			     !server_challenges.valid) ||
1865			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1866			     !proxy_challenges.valid)) {
1867				/* 401/7 but no www/proxy-authenticate ?? */
1868				DEBUG(fprintf(stderr, "401/7 and no auth header\n"));
1869				goto ouch;
1870			}
1871			fetch_close(conn);
1872			conn = NULL;
1873			continue;
1874		}
1875
1876		/* requested range not satisfiable */
1877		if (conn->err == HTTP_BAD_RANGE) {
1878			if (url->offset == size && url->length == 0) {
1879				/* asked for 0 bytes; fake it */
1880				offset = url->offset;
1881				clength = -1;
1882				conn->err = HTTP_OK;
1883				break;
1884			} else {
1885				http_seterr(conn->err);
1886				goto ouch;
1887			}
1888		}
1889
1890		/* we have a hit or an error */
1891		if (conn->err == HTTP_OK
1892		    || conn->err == HTTP_NOT_MODIFIED
1893		    || conn->err == HTTP_PARTIAL
1894		    || HTTP_ERROR(conn->err))
1895			break;
1896
1897		/* all other cases: we got a redirect */
1898		e = conn->err;
1899		clean_http_auth_challenges(&server_challenges);
1900		fetch_close(conn);
1901		conn = NULL;
1902		if (!new) {
1903			DEBUG(fprintf(stderr, "redirect with no new location\n"));
1904			break;
1905		}
1906		if (url != URL)
1907			fetchFreeURL(url);
1908		url = new;
1909	} while (++i < n);
1910
1911	/* we failed, or ran out of retries */
1912	if (conn == NULL) {
1913		http_seterr(e);
1914		goto ouch;
1915	}
1916
1917	DEBUG(fprintf(stderr, "offset %lld, length %lld,"
1918		  " size %lld, clength %lld\n",
1919		  (long long)offset, (long long)length,
1920		  (long long)size, (long long)clength));
1921
1922	if (conn->err == HTTP_NOT_MODIFIED) {
1923		http_seterr(HTTP_NOT_MODIFIED);
1924		return (NULL);
1925	}
1926
1927	/* check for inconsistencies */
1928	if (clength != -1 && length != -1 && clength != length) {
1929		http_seterr(HTTP_PROTOCOL_ERROR);
1930		goto ouch;
1931	}
1932	if (clength == -1)
1933		clength = length;
1934	if (clength != -1)
1935		length = offset + clength;
1936	if (length != -1 && size != -1 && length != size) {
1937		http_seterr(HTTP_PROTOCOL_ERROR);
1938		goto ouch;
1939	}
1940	if (size == -1)
1941		size = length;
1942
1943	/* fill in stats */
1944	if (us) {
1945		us->size = size;
1946		us->atime = us->mtime = mtime;
1947	}
1948
1949	/* too far? */
1950	if (URL->offset > 0 && offset > URL->offset) {
1951		http_seterr(HTTP_PROTOCOL_ERROR);
1952		goto ouch;
1953	}
1954
1955	/* report back real offset and size */
1956	URL->offset = offset;
1957	URL->length = clength;
1958
1959	/* wrap it up in a FILE */
1960	if ((f = http_funopen(conn, chunked)) == NULL) {
1961		fetch_syserr();
1962		goto ouch;
1963	}
1964
1965	if (url != URL)
1966		fetchFreeURL(url);
1967	if (purl)
1968		fetchFreeURL(purl);
1969
1970	if (HTTP_ERROR(conn->err)) {
1971		http_print_html(stderr, f);
1972		fclose(f);
1973		f = NULL;
1974	}
1975	clean_http_headerbuf(&headerbuf);
1976	clean_http_auth_challenges(&server_challenges);
1977	clean_http_auth_challenges(&proxy_challenges);
1978	return (f);
1979
1980ouch:
1981	if (url != URL)
1982		fetchFreeURL(url);
1983	if (purl)
1984		fetchFreeURL(purl);
1985	if (conn != NULL)
1986		fetch_close(conn);
1987	clean_http_headerbuf(&headerbuf);
1988	clean_http_auth_challenges(&server_challenges);
1989	clean_http_auth_challenges(&proxy_challenges);
1990	return (NULL);
1991}
1992
1993
1994/*****************************************************************************
1995 * Entry points
1996 */
1997
1998/*
1999 * Retrieve and stat a file by HTTP
2000 */
2001FILE *
2002fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
2003{
2004	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
2005}
2006
2007/*
2008 * Retrieve a file by HTTP
2009 */
2010FILE *
2011fetchGetHTTP(struct url *URL, const char *flags)
2012{
2013	return (fetchXGetHTTP(URL, NULL, flags));
2014}
2015
2016/*
2017 * Store a file by HTTP
2018 */
2019FILE *
2020fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2021{
2022	warnx("fetchPutHTTP(): not implemented");
2023	return (NULL);
2024}
2025
2026/*
2027 * Get an HTTP document's metadata
2028 */
2029int
2030fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2031{
2032	FILE *f;
2033
2034	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2035	if (f == NULL)
2036		return (-1);
2037	fclose(f);
2038	return (0);
2039}
2040
2041/*
2042 * List a directory
2043 */
2044struct url_ent *
2045fetchListHTTP(struct url *url __unused, const char *flags __unused)
2046{
2047	warnx("fetchListHTTP(): not implemented");
2048	return (NULL);
2049}
2050