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: stable/11/lib/libfetch/http.c 339250 2018-10-09 10:49:19Z 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_PERM_REDIRECT \
118			    || (xyz) == HTTP_USE_PROXY \
119			    || (xyz) == HTTP_SEE_OTHER)
120
121#define HTTP_ERROR(xyz) ((xyz) >= 400 && (xyz) <= 599)
122
123
124/*****************************************************************************
125 * I/O functions for decoding chunked streams
126 */
127
128struct httpio
129{
130	conn_t		*conn;		/* connection */
131	int		 chunked;	/* chunked mode */
132	char		*buf;		/* chunk buffer */
133	size_t		 bufsize;	/* size of chunk buffer */
134	size_t		 buflen;	/* amount of data currently in buffer */
135	size_t		 bufpos;	/* current read offset in buffer */
136	int		 eof;		/* end-of-file flag */
137	int		 error;		/* error flag */
138	size_t		 chunksize;	/* remaining size of current chunk */
139#ifndef NDEBUG
140	size_t		 total;
141#endif
142};
143
144/*
145 * Get next chunk header
146 */
147static int
148http_new_chunk(struct httpio *io)
149{
150	char *p;
151
152	if (fetch_getln(io->conn) == -1)
153		return (-1);
154
155	if (io->conn->buflen < 2 || !isxdigit((unsigned char)*io->conn->buf))
156		return (-1);
157
158	for (p = io->conn->buf; *p && !isspace((unsigned char)*p); ++p) {
159		if (*p == ';')
160			break;
161		if (!isxdigit((unsigned char)*p))
162			return (-1);
163		if (isdigit((unsigned char)*p)) {
164			io->chunksize = io->chunksize * 16 +
165			    *p - '0';
166		} else {
167			io->chunksize = io->chunksize * 16 +
168			    10 + tolower((unsigned char)*p) - 'a';
169		}
170	}
171
172#ifndef NDEBUG
173	if (fetchDebug) {
174		io->total += io->chunksize;
175		if (io->chunksize == 0)
176			fprintf(stderr, "%s(): end of last chunk\n", __func__);
177		else
178			fprintf(stderr, "%s(): new chunk: %lu (%lu)\n",
179			    __func__, (unsigned long)io->chunksize,
180			    (unsigned long)io->total);
181	}
182#endif
183
184	return (io->chunksize);
185}
186
187/*
188 * Grow the input buffer to at least len bytes
189 */
190static inline int
191http_growbuf(struct httpio *io, size_t len)
192{
193	char *tmp;
194
195	if (io->bufsize >= len)
196		return (0);
197
198	if ((tmp = realloc(io->buf, len)) == NULL)
199		return (-1);
200	io->buf = tmp;
201	io->bufsize = len;
202	return (0);
203}
204
205/*
206 * Fill the input buffer, do chunk decoding on the fly
207 */
208static ssize_t
209http_fillbuf(struct httpio *io, size_t len)
210{
211	ssize_t nbytes;
212	char ch;
213
214	if (io->error)
215		return (-1);
216	if (io->eof)
217		return (0);
218
219	/* not chunked: just fetch the requested amount */
220	if (io->chunked == 0) {
221		if (http_growbuf(io, len) == -1)
222			return (-1);
223		if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
224			io->error = errno;
225			return (-1);
226		}
227		io->buflen = nbytes;
228		io->bufpos = 0;
229		return (io->buflen);
230	}
231
232	/* chunked, but we ran out: get the next chunk header */
233	if (io->chunksize == 0) {
234		switch (http_new_chunk(io)) {
235		case -1:
236			io->error = EPROTO;
237			return (-1);
238		case 0:
239			io->eof = 1;
240			return (0);
241		}
242	}
243
244	/* fetch the requested amount, but no more than the current chunk */
245	if (len > io->chunksize)
246		len = io->chunksize;
247	if (http_growbuf(io, len) == -1)
248		return (-1);
249	if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
250		io->error = errno;
251		return (-1);
252	}
253	io->bufpos = 0;
254	io->buflen = nbytes;
255	io->chunksize -= nbytes;
256
257	if (io->chunksize == 0) {
258		if (fetch_read(io->conn, &ch, 1) != 1 || ch != '\r' ||
259		    fetch_read(io->conn, &ch, 1) != 1 || ch != '\n')
260			return (-1);
261	}
262
263	return (io->buflen);
264}
265
266/*
267 * Read function
268 */
269static int
270http_readfn(void *v, char *buf, int len)
271{
272	struct httpio *io = (struct httpio *)v;
273	int rlen;
274
275	if (io->error)
276		return (-1);
277	if (io->eof)
278		return (0);
279
280	/* empty buffer */
281	if (!io->buf || io->bufpos == io->buflen) {
282		if ((rlen = http_fillbuf(io, len)) < 0) {
283			if ((errno = io->error) == EINTR)
284				io->error = 0;
285			return (-1);
286		} else if (rlen == 0) {
287			return (0);
288		}
289	}
290
291	rlen = io->buflen - io->bufpos;
292	if (len < rlen)
293		rlen = len;
294	memcpy(buf, io->buf + io->bufpos, rlen);
295	io->bufpos += rlen;
296	return (rlen);
297}
298
299/*
300 * Write function
301 */
302static int
303http_writefn(void *v, const char *buf, int len)
304{
305	struct httpio *io = (struct httpio *)v;
306
307	return (fetch_write(io->conn, buf, len));
308}
309
310/*
311 * Close function
312 */
313static int
314http_closefn(void *v)
315{
316	struct httpio *io = (struct httpio *)v;
317	int r;
318
319	r = fetch_close(io->conn);
320	if (io->buf)
321		free(io->buf);
322	free(io);
323	return (r);
324}
325
326/*
327 * Wrap a file descriptor up
328 */
329static FILE *
330http_funopen(conn_t *conn, int chunked)
331{
332	struct httpio *io;
333	FILE *f;
334
335	if ((io = calloc(1, sizeof(*io))) == NULL) {
336		fetch_syserr();
337		return (NULL);
338	}
339	io->conn = conn;
340	io->chunked = chunked;
341	f = funopen(io, http_readfn, http_writefn, NULL, http_closefn);
342	if (f == NULL) {
343		fetch_syserr();
344		free(io);
345		return (NULL);
346	}
347	return (f);
348}
349
350
351/*****************************************************************************
352 * Helper functions for talking to the server and parsing its replies
353 */
354
355/* Header types */
356typedef enum {
357	hdr_syserror = -2,
358	hdr_error = -1,
359	hdr_end = 0,
360	hdr_unknown = 1,
361	hdr_content_length,
362	hdr_content_range,
363	hdr_last_modified,
364	hdr_location,
365	hdr_transfer_encoding,
366	hdr_www_authenticate,
367	hdr_proxy_authenticate,
368} hdr_t;
369
370/* Names of interesting headers */
371static struct {
372	hdr_t		 num;
373	const char	*name;
374} hdr_names[] = {
375	{ hdr_content_length,		"Content-Length" },
376	{ hdr_content_range,		"Content-Range" },
377	{ hdr_last_modified,		"Last-Modified" },
378	{ hdr_location,			"Location" },
379	{ hdr_transfer_encoding,	"Transfer-Encoding" },
380	{ hdr_www_authenticate,		"WWW-Authenticate" },
381	{ hdr_proxy_authenticate,	"Proxy-Authenticate" },
382	{ hdr_unknown,			NULL },
383};
384
385/*
386 * Send a formatted line; optionally echo to terminal
387 */
388static int
389http_cmd(conn_t *conn, const char *fmt, ...)
390{
391	va_list ap;
392	size_t len;
393	char *msg;
394	int r;
395
396	va_start(ap, fmt);
397	len = vasprintf(&msg, fmt, ap);
398	va_end(ap);
399
400	if (msg == NULL) {
401		errno = ENOMEM;
402		fetch_syserr();
403		return (-1);
404	}
405
406	r = fetch_putln(conn, msg, len);
407	free(msg);
408
409	if (r == -1) {
410		fetch_syserr();
411		return (-1);
412	}
413
414	return (0);
415}
416
417/*
418 * Get and parse status line
419 */
420static int
421http_get_reply(conn_t *conn)
422{
423	char *p;
424
425	if (fetch_getln(conn) == -1)
426		return (-1);
427	/*
428	 * A valid status line looks like "HTTP/m.n xyz reason" where m
429	 * and n are the major and minor protocol version numbers and xyz
430	 * is the reply code.
431	 * Unfortunately, there are servers out there (NCSA 1.5.1, to name
432	 * just one) that do not send a version number, so we can't rely
433	 * on finding one, but if we do, insist on it being 1.0 or 1.1.
434	 * We don't care about the reason phrase.
435	 */
436	if (strncmp(conn->buf, "HTTP", 4) != 0)
437		return (HTTP_PROTOCOL_ERROR);
438	p = conn->buf + 4;
439	if (*p == '/') {
440		if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
441			return (HTTP_PROTOCOL_ERROR);
442		p += 4;
443	}
444	if (*p != ' ' ||
445	    !isdigit((unsigned char)p[1]) ||
446	    !isdigit((unsigned char)p[2]) ||
447	    !isdigit((unsigned char)p[3]))
448		return (HTTP_PROTOCOL_ERROR);
449
450	conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
451	return (conn->err);
452}
453
454/*
455 * Check a header; if the type matches the given string, return a pointer
456 * to the beginning of the value.
457 */
458static const char *
459http_match(const char *str, const char *hdr)
460{
461	while (*str && *hdr &&
462	    tolower((unsigned char)*str++) == tolower((unsigned char)*hdr++))
463		/* nothing */;
464	if (*str || *hdr != ':')
465		return (NULL);
466	while (*hdr && isspace((unsigned char)*++hdr))
467		/* nothing */;
468	return (hdr);
469}
470
471
472/*
473 * Get the next header and return the appropriate symbolic code.  We
474 * need to read one line ahead for checking for a continuation line
475 * belonging to the current header (continuation lines start with
476 * white space).
477 *
478 * We get called with a fresh line already in the conn buffer, either
479 * from the previous http_next_header() invocation, or, the first
480 * time, from a fetch_getln() performed by our caller.
481 *
482 * This stops when we encounter an empty line (we dont read beyond the header
483 * area).
484 *
485 * Note that the "headerbuf" is just a place to return the result. Its
486 * contents are not used for the next call. This means that no cleanup
487 * is needed when ie doing another connection, just call the cleanup when
488 * fully done to deallocate memory.
489 */
490
491/* Limit the max number of continuation lines to some reasonable value */
492#define HTTP_MAX_CONT_LINES 10
493
494/* Place into which to build a header from one or several lines */
495typedef struct {
496	char	*buf;		/* buffer */
497	size_t	 bufsize;	/* buffer size */
498	size_t	 buflen;	/* length of buffer contents */
499} http_headerbuf_t;
500
501static void
502init_http_headerbuf(http_headerbuf_t *buf)
503{
504	buf->buf = NULL;
505	buf->bufsize = 0;
506	buf->buflen = 0;
507}
508
509static void
510clean_http_headerbuf(http_headerbuf_t *buf)
511{
512	if (buf->buf)
513		free(buf->buf);
514	init_http_headerbuf(buf);
515}
516
517/* Remove whitespace at the end of the buffer */
518static void
519http_conn_trimright(conn_t *conn)
520{
521	while (conn->buflen &&
522	       isspace((unsigned char)conn->buf[conn->buflen - 1]))
523		conn->buflen--;
524	conn->buf[conn->buflen] = '\0';
525}
526
527static hdr_t
528http_next_header(conn_t *conn, http_headerbuf_t *hbuf, const char **p)
529{
530	unsigned int i, len;
531
532	/*
533	 * Have to do the stripping here because of the first line. So
534	 * it's done twice for the subsequent lines. No big deal
535	 */
536	http_conn_trimright(conn);
537	if (conn->buflen == 0)
538		return (hdr_end);
539
540	/* Copy the line to the headerbuf */
541	if (hbuf->bufsize < conn->buflen + 1) {
542		if ((hbuf->buf = realloc(hbuf->buf, conn->buflen + 1)) == NULL)
543			return (hdr_syserror);
544		hbuf->bufsize = conn->buflen + 1;
545	}
546	strcpy(hbuf->buf, conn->buf);
547	hbuf->buflen = conn->buflen;
548
549	/*
550	 * Fetch possible continuation lines. Stop at 1st non-continuation
551	 * and leave it in the conn buffer
552	 */
553	for (i = 0; i < HTTP_MAX_CONT_LINES; i++) {
554		if (fetch_getln(conn) == -1)
555			return (hdr_syserror);
556
557		/*
558		 * Note: we carry on the idea from the previous version
559		 * that a pure whitespace line is equivalent to an empty
560		 * one (so it's not continuation and will be handled when
561		 * we are called next)
562		 */
563		http_conn_trimright(conn);
564		if (conn->buf[0] != ' ' && conn->buf[0] != "\t"[0])
565			break;
566
567		/* Got a continuation line. Concatenate to previous */
568		len = hbuf->buflen + conn->buflen;
569		if (hbuf->bufsize < len + 1) {
570			len *= 2;
571			if ((hbuf->buf = realloc(hbuf->buf, len + 1)) == NULL)
572				return (hdr_syserror);
573			hbuf->bufsize = len + 1;
574		}
575		strcpy(hbuf->buf + hbuf->buflen, conn->buf);
576		hbuf->buflen += conn->buflen;
577	}
578
579	/*
580	 * We could check for malformed headers but we don't really care.
581	 * A valid header starts with a token immediately followed by a
582	 * colon; a token is any sequence of non-control, non-whitespace
583	 * characters except "()<>@,;:\\\"{}".
584	 */
585	for (i = 0; hdr_names[i].num != hdr_unknown; i++)
586		if ((*p = http_match(hdr_names[i].name, hbuf->buf)) != NULL)
587			return (hdr_names[i].num);
588
589	return (hdr_unknown);
590}
591
592/**************************
593 * [Proxy-]Authenticate header parsing
594 */
595
596/*
597 * Read doublequote-delimited string into output buffer obuf (allocated
598 * by caller, whose responsibility it is to ensure that it's big enough)
599 * cp points to the first char after the initial '"'
600 * Handles \ quoting
601 * Returns pointer to the first char after the terminating double quote, or
602 * NULL for error.
603 */
604static const char *
605http_parse_headerstring(const char *cp, char *obuf)
606{
607	for (;;) {
608		switch (*cp) {
609		case 0: /* Unterminated string */
610			*obuf = 0;
611			return (NULL);
612		case '"': /* Ending quote */
613			*obuf = 0;
614			return (++cp);
615		case '\\':
616			if (*++cp == 0) {
617				*obuf = 0;
618				return (NULL);
619			}
620			/* FALLTHROUGH */
621		default:
622			*obuf++ = *cp++;
623		}
624	}
625}
626
627/* Http auth challenge schemes */
628typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
629
630/* Data holder for a Basic or Digest challenge. */
631typedef struct {
632	http_auth_schemes_t scheme;
633	char	*realm;
634	char	*qop;
635	char	*nonce;
636	char	*opaque;
637	char	*algo;
638	int	 stale;
639	int	 nc; /* Nonce count */
640} http_auth_challenge_t;
641
642static void
643init_http_auth_challenge(http_auth_challenge_t *b)
644{
645	b->scheme = HTTPAS_UNKNOWN;
646	b->realm = b->qop = b->nonce = b->opaque = b->algo = NULL;
647	b->stale = b->nc = 0;
648}
649
650static void
651clean_http_auth_challenge(http_auth_challenge_t *b)
652{
653	if (b->realm)
654		free(b->realm);
655	if (b->qop)
656		free(b->qop);
657	if (b->nonce)
658		free(b->nonce);
659	if (b->opaque)
660		free(b->opaque);
661	if (b->algo)
662		free(b->algo);
663	init_http_auth_challenge(b);
664}
665
666/* Data holder for an array of challenges offered in an http response. */
667#define MAX_CHALLENGES 10
668typedef struct {
669	http_auth_challenge_t *challenges[MAX_CHALLENGES];
670	int	count; /* Number of parsed challenges in the array */
671	int	valid; /* We did parse an authenticate header */
672} http_auth_challenges_t;
673
674static void
675init_http_auth_challenges(http_auth_challenges_t *cs)
676{
677	int i;
678	for (i = 0; i < MAX_CHALLENGES; i++)
679		cs->challenges[i] = NULL;
680	cs->count = cs->valid = 0;
681}
682
683static void
684clean_http_auth_challenges(http_auth_challenges_t *cs)
685{
686	int i;
687	/* We rely on non-zero pointers being allocated, not on the count */
688	for (i = 0; i < MAX_CHALLENGES; i++) {
689		if (cs->challenges[i] != NULL) {
690			clean_http_auth_challenge(cs->challenges[i]);
691			free(cs->challenges[i]);
692		}
693	}
694	init_http_auth_challenges(cs);
695}
696
697/*
698 * Enumeration for lexical elements. Separators will be returned as their own
699 * ascii value
700 */
701typedef enum {HTTPHL_WORD=256, HTTPHL_STRING=257, HTTPHL_END=258,
702	      HTTPHL_ERROR = 259} http_header_lex_t;
703
704/*
705 * Determine what kind of token comes next and return possible value
706 * in buf, which is supposed to have been allocated big enough by
707 * caller. Advance input pointer and return element type.
708 */
709static int
710http_header_lex(const char **cpp, char *buf)
711{
712	size_t l;
713	/* Eat initial whitespace */
714	*cpp += strspn(*cpp, " \t");
715	if (**cpp == 0)
716		return (HTTPHL_END);
717
718	/* Separator ? */
719	if (**cpp == ',' || **cpp == '=')
720		return (*((*cpp)++));
721
722	/* String ? */
723	if (**cpp == '"') {
724		*cpp = http_parse_headerstring(++*cpp, buf);
725		if (*cpp == NULL)
726			return (HTTPHL_ERROR);
727		return (HTTPHL_STRING);
728	}
729
730	/* Read other token, until separator or whitespace */
731	l = strcspn(*cpp, " \t,=");
732	memcpy(buf, *cpp, l);
733	buf[l] = 0;
734	*cpp += l;
735	return (HTTPHL_WORD);
736}
737
738/*
739 * Read challenges from http xxx-authenticate header and accumulate them
740 * in the challenges list structure.
741 *
742 * Headers with multiple challenges are specified by rfc2617, but
743 * servers (ie: squid) often send them in separate headers instead,
744 * which in turn is forbidden by the http spec (multiple headers with
745 * the same name are only allowed for pure comma-separated lists, see
746 * rfc2616 sec 4.2).
747 *
748 * We support both approaches anyway
749 */
750static int
751http_parse_authenticate(const char *cp, http_auth_challenges_t *cs)
752{
753	int ret = -1;
754	http_header_lex_t lex;
755	char *key = malloc(strlen(cp) + 1);
756	char *value = malloc(strlen(cp) + 1);
757	char *buf = malloc(strlen(cp) + 1);
758
759	if (key == NULL || value == NULL || buf == NULL) {
760		fetch_syserr();
761		goto out;
762	}
763
764	/* In any case we've seen the header and we set the valid bit */
765	cs->valid = 1;
766
767	/* Need word first */
768	lex = http_header_lex(&cp, key);
769	if (lex != HTTPHL_WORD)
770		goto out;
771
772	/* Loop on challenges */
773	for (; cs->count < MAX_CHALLENGES; cs->count++) {
774		cs->challenges[cs->count] =
775			malloc(sizeof(http_auth_challenge_t));
776		if (cs->challenges[cs->count] == NULL) {
777			fetch_syserr();
778			goto out;
779		}
780		init_http_auth_challenge(cs->challenges[cs->count]);
781		if (strcasecmp(key, "basic") == 0) {
782			cs->challenges[cs->count]->scheme = HTTPAS_BASIC;
783		} else if (strcasecmp(key, "digest") == 0) {
784			cs->challenges[cs->count]->scheme = HTTPAS_DIGEST;
785		} else {
786			cs->challenges[cs->count]->scheme = HTTPAS_UNKNOWN;
787			/*
788			 * Continue parsing as basic or digest may
789			 * follow, and the syntax is the same for
790			 * all. We'll just ignore this one when
791			 * looking at the list
792			 */
793		}
794
795		/* Loop on attributes */
796		for (;;) {
797			/* Key */
798			lex = http_header_lex(&cp, key);
799			if (lex != HTTPHL_WORD)
800				goto out;
801
802			/* Equal sign */
803			lex = http_header_lex(&cp, buf);
804			if (lex != '=')
805				goto out;
806
807			/* Value */
808			lex = http_header_lex(&cp, value);
809			if (lex != HTTPHL_WORD && lex != HTTPHL_STRING)
810				goto out;
811
812			if (strcasecmp(key, "realm") == 0) {
813				cs->challenges[cs->count]->realm =
814				    strdup(value);
815			} else if (strcasecmp(key, "qop") == 0) {
816				cs->challenges[cs->count]->qop =
817				    strdup(value);
818			} else if (strcasecmp(key, "nonce") == 0) {
819				cs->challenges[cs->count]->nonce =
820				    strdup(value);
821			} else if (strcasecmp(key, "opaque") == 0) {
822				cs->challenges[cs->count]->opaque =
823				    strdup(value);
824			} else if (strcasecmp(key, "algorithm") == 0) {
825				cs->challenges[cs->count]->algo =
826				    strdup(value);
827			} else if (strcasecmp(key, "stale") == 0) {
828				cs->challenges[cs->count]->stale =
829				    strcasecmp(value, "no");
830			} else {
831				/* ignore unknown attributes */
832			}
833
834			/* Comma or Next challenge or End */
835			lex = http_header_lex(&cp, key);
836			/*
837			 * If we get a word here, this is the beginning of the
838			 * next challenge. Break the attributes loop
839			 */
840			if (lex == HTTPHL_WORD)
841				break;
842
843			if (lex == HTTPHL_END) {
844				/* End while looking for ',' is normal exit */
845				cs->count++;
846				ret = 0;
847				goto out;
848			}
849			/* Anything else is an error */
850			if (lex != ',')
851				goto out;
852
853		} /* End attributes loop */
854	} /* End challenge loop */
855
856	/*
857	 * Challenges max count exceeded. This really can't happen
858	 * with normal data, something's fishy -> error
859	 */
860
861out:
862	if (key)
863		free(key);
864	if (value)
865		free(value);
866	if (buf)
867		free(buf);
868	return (ret);
869}
870
871
872/*
873 * Parse a last-modified header
874 */
875static int
876http_parse_mtime(const char *p, time_t *mtime)
877{
878	char locale[64], *r;
879	struct tm tm;
880
881	strlcpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
882	setlocale(LC_TIME, "C");
883	r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
884	/*
885	 * Some proxies use UTC in response, but it should still be
886	 * parsed. RFC2616 states GMT and UTC are exactly equal for HTTP.
887	 */
888	if (r == NULL)
889		r = strptime(p, "%a, %d %b %Y %H:%M:%S UTC", &tm);
890	/* XXX should add support for date-2 and date-3 */
891	setlocale(LC_TIME, locale);
892	if (r == NULL)
893		return (-1);
894	DEBUGF("last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
895	    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
896	    tm.tm_hour, tm.tm_min, tm.tm_sec);
897	*mtime = timegm(&tm);
898	return (0);
899}
900
901/*
902 * Parse a content-length header
903 */
904static int
905http_parse_length(const char *p, off_t *length)
906{
907	off_t len;
908
909	for (len = 0; *p && isdigit((unsigned char)*p); ++p)
910		len = len * 10 + (*p - '0');
911	if (*p)
912		return (-1);
913	DEBUGF("content length: [%lld]\n", (long long)len);
914	*length = len;
915	return (0);
916}
917
918/*
919 * Parse a content-range header
920 */
921static int
922http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
923{
924	off_t first, last, len;
925
926	if (strncasecmp(p, "bytes ", 6) != 0)
927		return (-1);
928	p += 6;
929	if (*p == '*') {
930		first = last = -1;
931		++p;
932	} else {
933		for (first = 0; *p && isdigit((unsigned char)*p); ++p)
934			first = first * 10 + *p - '0';
935		if (*p != '-')
936			return (-1);
937		for (last = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
938			last = last * 10 + *p - '0';
939	}
940	if (first > last || *p != '/')
941		return (-1);
942	for (len = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
943		len = len * 10 + *p - '0';
944	if (*p || len < last - first + 1)
945		return (-1);
946	if (first == -1) {
947		DEBUGF("content range: [*/%lld]\n", (long long)len);
948		*length = 0;
949	} else {
950		DEBUGF("content range: [%lld-%lld/%lld]\n",
951		    (long long)first, (long long)last, (long long)len);
952		*length = last - first + 1;
953	}
954	*offset = first;
955	*size = len;
956	return (0);
957}
958
959
960/*****************************************************************************
961 * Helper functions for authorization
962 */
963
964/*
965 * Base64 encoding
966 */
967static char *
968http_base64(const char *src)
969{
970	static const char base64[] =
971	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
972	    "abcdefghijklmnopqrstuvwxyz"
973	    "0123456789+/";
974	char *str, *dst;
975	size_t l;
976	int t, r;
977
978	l = strlen(src);
979	if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
980		return (NULL);
981	dst = str;
982	r = 0;
983
984	while (l >= 3) {
985		t = (src[0] << 16) | (src[1] << 8) | src[2];
986		dst[0] = base64[(t >> 18) & 0x3f];
987		dst[1] = base64[(t >> 12) & 0x3f];
988		dst[2] = base64[(t >> 6) & 0x3f];
989		dst[3] = base64[(t >> 0) & 0x3f];
990		src += 3; l -= 3;
991		dst += 4; r += 4;
992	}
993
994	switch (l) {
995	case 2:
996		t = (src[0] << 16) | (src[1] << 8);
997		dst[0] = base64[(t >> 18) & 0x3f];
998		dst[1] = base64[(t >> 12) & 0x3f];
999		dst[2] = base64[(t >> 6) & 0x3f];
1000		dst[3] = '=';
1001		dst += 4;
1002		r += 4;
1003		break;
1004	case 1:
1005		t = src[0] << 16;
1006		dst[0] = base64[(t >> 18) & 0x3f];
1007		dst[1] = base64[(t >> 12) & 0x3f];
1008		dst[2] = dst[3] = '=';
1009		dst += 4;
1010		r += 4;
1011		break;
1012	case 0:
1013		break;
1014	}
1015
1016	*dst = 0;
1017	return (str);
1018}
1019
1020
1021/*
1022 * Extract authorization parameters from environment value.
1023 * The value is like scheme:realm:user:pass
1024 */
1025typedef struct {
1026	char	*scheme;
1027	char	*realm;
1028	char	*user;
1029	char	*password;
1030} http_auth_params_t;
1031
1032static void
1033init_http_auth_params(http_auth_params_t *s)
1034{
1035	s->scheme = s->realm = s->user = s->password = NULL;
1036}
1037
1038static void
1039clean_http_auth_params(http_auth_params_t *s)
1040{
1041	if (s->scheme)
1042		free(s->scheme);
1043	if (s->realm)
1044		free(s->realm);
1045	if (s->user)
1046		free(s->user);
1047	if (s->password)
1048		free(s->password);
1049	init_http_auth_params(s);
1050}
1051
1052static int
1053http_authfromenv(const char *p, http_auth_params_t *parms)
1054{
1055	int ret = -1;
1056	char *v, *ve;
1057	char *str = strdup(p);
1058
1059	if (str == NULL) {
1060		fetch_syserr();
1061		return (-1);
1062	}
1063	v = str;
1064
1065	if ((ve = strchr(v, ':')) == NULL)
1066		goto out;
1067
1068	*ve = 0;
1069	if ((parms->scheme = strdup(v)) == NULL) {
1070		fetch_syserr();
1071		goto out;
1072	}
1073	v = ve + 1;
1074
1075	if ((ve = strchr(v, ':')) == NULL)
1076		goto out;
1077
1078	*ve = 0;
1079	if ((parms->realm = strdup(v)) == NULL) {
1080		fetch_syserr();
1081		goto out;
1082	}
1083	v = ve + 1;
1084
1085	if ((ve = strchr(v, ':')) == NULL)
1086		goto out;
1087
1088	*ve = 0;
1089	if ((parms->user = strdup(v)) == NULL) {
1090		fetch_syserr();
1091		goto out;
1092	}
1093	v = ve + 1;
1094
1095
1096	if ((parms->password = strdup(v)) == NULL) {
1097		fetch_syserr();
1098		goto out;
1099	}
1100	ret = 0;
1101out:
1102	if (ret == -1)
1103		clean_http_auth_params(parms);
1104	if (str)
1105		free(str);
1106	return (ret);
1107}
1108
1109
1110/*
1111 * Digest response: the code to compute the digest is taken from the
1112 * sample implementation in RFC2616
1113 */
1114#define IN const
1115#define OUT
1116
1117#define HASHLEN 16
1118typedef char HASH[HASHLEN];
1119#define HASHHEXLEN 32
1120typedef char HASHHEX[HASHHEXLEN+1];
1121
1122static const char *hexchars = "0123456789abcdef";
1123static void
1124CvtHex(IN HASH Bin, OUT HASHHEX Hex)
1125{
1126	unsigned short i;
1127	unsigned char j;
1128
1129	for (i = 0; i < HASHLEN; i++) {
1130		j = (Bin[i] >> 4) & 0xf;
1131		Hex[i*2] = hexchars[j];
1132		j = Bin[i] & 0xf;
1133		Hex[i*2+1] = hexchars[j];
1134	}
1135	Hex[HASHHEXLEN] = '\0';
1136};
1137
1138/* calculate H(A1) as per spec */
1139static void
1140DigestCalcHA1(
1141	IN char * pszAlg,
1142	IN char * pszUserName,
1143	IN char * pszRealm,
1144	IN char * pszPassword,
1145	IN char * pszNonce,
1146	IN char * pszCNonce,
1147	OUT HASHHEX SessionKey
1148	)
1149{
1150	MD5_CTX Md5Ctx;
1151	HASH HA1;
1152
1153	MD5Init(&Md5Ctx);
1154	MD5Update(&Md5Ctx, pszUserName, strlen(pszUserName));
1155	MD5Update(&Md5Ctx, ":", 1);
1156	MD5Update(&Md5Ctx, pszRealm, strlen(pszRealm));
1157	MD5Update(&Md5Ctx, ":", 1);
1158	MD5Update(&Md5Ctx, pszPassword, strlen(pszPassword));
1159	MD5Final(HA1, &Md5Ctx);
1160	if (strcasecmp(pszAlg, "md5-sess") == 0) {
1161
1162		MD5Init(&Md5Ctx);
1163		MD5Update(&Md5Ctx, HA1, HASHLEN);
1164		MD5Update(&Md5Ctx, ":", 1);
1165		MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1166		MD5Update(&Md5Ctx, ":", 1);
1167		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1168		MD5Final(HA1, &Md5Ctx);
1169	}
1170	CvtHex(HA1, SessionKey);
1171}
1172
1173/* calculate request-digest/response-digest as per HTTP Digest spec */
1174static void
1175DigestCalcResponse(
1176	IN HASHHEX HA1,           /* H(A1) */
1177	IN char * pszNonce,       /* nonce from server */
1178	IN char * pszNonceCount,  /* 8 hex digits */
1179	IN char * pszCNonce,      /* client nonce */
1180	IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
1181	IN char * pszMethod,      /* method from the request */
1182	IN char * pszDigestUri,   /* requested URL */
1183	IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
1184	OUT HASHHEX Response      /* request-digest or response-digest */
1185	)
1186{
1187#if 0
1188	DEBUGF("Calc: HA1[%s] Nonce[%s] qop[%s] method[%s] URI[%s]\n",
1189	    HA1, pszNonce, pszQop, pszMethod, pszDigestUri);
1190#endif
1191	MD5_CTX Md5Ctx;
1192	HASH HA2;
1193	HASH RespHash;
1194	HASHHEX HA2Hex;
1195
1196	// calculate H(A2)
1197	MD5Init(&Md5Ctx);
1198	MD5Update(&Md5Ctx, pszMethod, strlen(pszMethod));
1199	MD5Update(&Md5Ctx, ":", 1);
1200	MD5Update(&Md5Ctx, pszDigestUri, strlen(pszDigestUri));
1201	if (strcasecmp(pszQop, "auth-int") == 0) {
1202		MD5Update(&Md5Ctx, ":", 1);
1203		MD5Update(&Md5Ctx, HEntity, HASHHEXLEN);
1204	}
1205	MD5Final(HA2, &Md5Ctx);
1206	CvtHex(HA2, HA2Hex);
1207
1208	// calculate response
1209	MD5Init(&Md5Ctx);
1210	MD5Update(&Md5Ctx, HA1, HASHHEXLEN);
1211	MD5Update(&Md5Ctx, ":", 1);
1212	MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1213	MD5Update(&Md5Ctx, ":", 1);
1214	if (*pszQop) {
1215		MD5Update(&Md5Ctx, pszNonceCount, strlen(pszNonceCount));
1216		MD5Update(&Md5Ctx, ":", 1);
1217		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1218		MD5Update(&Md5Ctx, ":", 1);
1219		MD5Update(&Md5Ctx, pszQop, strlen(pszQop));
1220		MD5Update(&Md5Ctx, ":", 1);
1221	}
1222	MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
1223	MD5Final(RespHash, &Md5Ctx);
1224	CvtHex(RespHash, Response);
1225}
1226
1227/*
1228 * Generate/Send a Digest authorization header
1229 * This looks like: [Proxy-]Authorization: credentials
1230 *
1231 *  credentials      = "Digest" digest-response
1232 *  digest-response  = 1#( username | realm | nonce | digest-uri
1233 *                      | response | [ algorithm ] | [cnonce] |
1234 *                      [opaque] | [message-qop] |
1235 *                          [nonce-count]  | [auth-param] )
1236 *  username         = "username" "=" username-value
1237 *  username-value   = quoted-string
1238 *  digest-uri       = "uri" "=" digest-uri-value
1239 *  digest-uri-value = request-uri   ; As specified by HTTP/1.1
1240 *  message-qop      = "qop" "=" qop-value
1241 *  cnonce           = "cnonce" "=" cnonce-value
1242 *  cnonce-value     = nonce-value
1243 *  nonce-count      = "nc" "=" nc-value
1244 *  nc-value         = 8LHEX
1245 *  response         = "response" "=" request-digest
1246 *  request-digest = <"> 32LHEX <">
1247 */
1248static int
1249http_digest_auth(conn_t *conn, const char *hdr, http_auth_challenge_t *c,
1250		 http_auth_params_t *parms, struct url *url)
1251{
1252	int r;
1253	char noncecount[10];
1254	char cnonce[40];
1255	char *options = NULL;
1256
1257	if (!c->realm || !c->nonce) {
1258		DEBUGF("realm/nonce not set in challenge\n");
1259		return(-1);
1260	}
1261	if (!c->algo)
1262		c->algo = strdup("");
1263
1264	if (asprintf(&options, "%s%s%s%s",
1265	    *c->algo? ",algorithm=" : "", c->algo,
1266	    c->opaque? ",opaque=" : "", c->opaque?c->opaque:"") < 0)
1267		return (-1);
1268
1269	if (!c->qop) {
1270		c->qop = strdup("");
1271		*noncecount = 0;
1272		*cnonce = 0;
1273	} else {
1274		c->nc++;
1275		sprintf(noncecount, "%08x", c->nc);
1276		/* We don't try very hard with the cnonce ... */
1277		sprintf(cnonce, "%x%lx", getpid(), (unsigned long)time(0));
1278	}
1279
1280	HASHHEX HA1;
1281	DigestCalcHA1(c->algo, parms->user, c->realm,
1282		      parms->password, c->nonce, cnonce, HA1);
1283	DEBUGF("HA1: [%s]\n", HA1);
1284	HASHHEX digest;
1285	DigestCalcResponse(HA1, c->nonce, noncecount, cnonce, c->qop,
1286			   "GET", url->doc, "", digest);
1287
1288	if (c->qop[0]) {
1289		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1290			     "nonce=\"%s\",uri=\"%s\",response=\"%s\","
1291			     "qop=\"auth\", cnonce=\"%s\", nc=%s%s",
1292			     hdr, parms->user, c->realm,
1293			     c->nonce, url->doc, digest,
1294			     cnonce, noncecount, options);
1295	} else {
1296		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1297			     "nonce=\"%s\",uri=\"%s\",response=\"%s\"%s",
1298			     hdr, parms->user, c->realm,
1299			     c->nonce, url->doc, digest, options);
1300	}
1301	if (options)
1302		free(options);
1303	return (r);
1304}
1305
1306/*
1307 * Encode username and password
1308 */
1309static int
1310http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
1311{
1312	char *upw, *auth;
1313	int r;
1314
1315	DEBUGF("basic: usr: [%s]\n", usr);
1316	DEBUGF("basic: pwd: [%s]\n", pwd);
1317	if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
1318		return (-1);
1319	auth = http_base64(upw);
1320	free(upw);
1321	if (auth == NULL)
1322		return (-1);
1323	r = http_cmd(conn, "%s: Basic %s", hdr, auth);
1324	free(auth);
1325	return (r);
1326}
1327
1328/*
1329 * Chose the challenge to answer and call the appropriate routine to
1330 * produce the header.
1331 */
1332static int
1333http_authorize(conn_t *conn, const char *hdr, http_auth_challenges_t *cs,
1334	       http_auth_params_t *parms, struct url *url)
1335{
1336	http_auth_challenge_t *digest = NULL;
1337	int i;
1338
1339	/* If user or pass are null we're not happy */
1340	if (!parms->user || !parms->password) {
1341		DEBUGF("NULL usr or pass\n");
1342		return (-1);
1343	}
1344
1345	/* Look for a Digest */
1346	for (i = 0; i < cs->count; 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 &&
1353	    (parms->scheme && strcasecmp(parms->scheme, "digest") == 0)) {
1354		DEBUGF("Digest auth in env, not supported by peer\n");
1355		return (-1);
1356	}
1357	/*
1358	 * If "basic" was specified in the environment, or there is no Digest
1359	 * challenge, do the basic thing. Don't need a challenge for this,
1360	 * so no need to check basic!=NULL
1361	 */
1362	if (!digest ||
1363	    (parms->scheme && strcasecmp(parms->scheme, "basic") == 0))
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	hdr_t h;
1383	http_headerbuf_t headerbuf;
1384	const char *p;
1385	int verbose;
1386	int af, val;
1387	int serrno;
1388
1389#ifdef INET6
1390	af = AF_UNSPEC;
1391#else
1392	af = AF_INET;
1393#endif
1394
1395	verbose = CHECK_FLAG('v');
1396	if (CHECK_FLAG('4'))
1397		af = AF_INET;
1398#ifdef INET6
1399	else if (CHECK_FLAG('6'))
1400		af = AF_INET6;
1401#endif
1402
1403	curl = (purl != NULL) ? purl : URL;
1404
1405	if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1406		/* fetch_connect() has already set an error code */
1407		return (NULL);
1408	init_http_headerbuf(&headerbuf);
1409	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1410		http_cmd(conn, "CONNECT %s:%d HTTP/1.1",
1411		    URL->host, URL->port);
1412		http_cmd(conn, "Host: %s:%d",
1413		    URL->host, URL->port);
1414		http_cmd(conn, "");
1415		if (http_get_reply(conn) != HTTP_OK) {
1416			http_seterr(conn->err);
1417			goto ouch;
1418		}
1419		/* Read and discard the rest of the proxy response */
1420		if (fetch_getln(conn) < 0) {
1421			fetch_syserr();
1422			goto ouch;
1423		}
1424		do {
1425			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1426			case hdr_syserror:
1427				fetch_syserr();
1428				goto ouch;
1429			case hdr_error:
1430				http_seterr(HTTP_PROTOCOL_ERROR);
1431				goto ouch;
1432			default:
1433				/* ignore */ ;
1434			}
1435		} while (h > hdr_end);
1436	}
1437	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1438	    fetch_ssl(conn, URL, verbose) == -1) {
1439		/* grrr */
1440		errno = EAUTH;
1441		fetch_syserr();
1442		goto ouch;
1443	}
1444
1445	val = 1;
1446	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1447
1448	clean_http_headerbuf(&headerbuf);
1449	return (conn);
1450ouch:
1451	serrno = errno;
1452	clean_http_headerbuf(&headerbuf);
1453	fetch_close(conn);
1454	errno = serrno;
1455	return (NULL);
1456}
1457
1458static struct url *
1459http_get_proxy(struct url * url, const char *flags)
1460{
1461	struct url *purl;
1462	char *p;
1463
1464	if (flags != NULL && strchr(flags, 'd') != NULL)
1465		return (NULL);
1466	if (fetch_no_proxy_match(url->host))
1467		return (NULL);
1468	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1469	    *p && (purl = fetchParseURL(p))) {
1470		if (!*purl->scheme)
1471			strcpy(purl->scheme, SCHEME_HTTP);
1472		if (!purl->port)
1473			purl->port = fetch_default_proxy_port(purl->scheme);
1474		if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1475			return (purl);
1476		fetchFreeURL(purl);
1477	}
1478	return (NULL);
1479}
1480
1481static void
1482http_print_html(FILE *out, FILE *in)
1483{
1484	size_t len;
1485	char *line, *p, *q;
1486	int comment, tag;
1487
1488	comment = tag = 0;
1489	while ((line = fgetln(in, &len)) != NULL) {
1490		while (len && isspace((unsigned char)line[len - 1]))
1491			--len;
1492		for (p = q = line; q < line + len; ++q) {
1493			if (comment && *q == '-') {
1494				if (q + 2 < line + len &&
1495				    strcmp(q, "-->") == 0) {
1496					tag = comment = 0;
1497					q += 2;
1498				}
1499			} else if (tag && !comment && *q == '>') {
1500				p = q + 1;
1501				tag = 0;
1502			} else if (!tag && *q == '<') {
1503				if (q > p)
1504					fwrite(p, q - p, 1, out);
1505				tag = 1;
1506				if (q + 3 < line + len &&
1507				    strcmp(q, "<!--") == 0) {
1508					comment = 1;
1509					q += 3;
1510				}
1511			}
1512		}
1513		if (!tag && q > p)
1514			fwrite(p, q - p, 1, out);
1515		fputc('\n', out);
1516	}
1517}
1518
1519
1520/*****************************************************************************
1521 * Core
1522 */
1523
1524FILE *
1525http_request(struct url *URL, const char *op, struct url_stat *us,
1526	struct url *purl, const char *flags)
1527{
1528
1529	return (http_request_body(URL, op, us, purl, flags, NULL, NULL));
1530}
1531
1532/*
1533 * Send a request and process the reply
1534 *
1535 * XXX This function is way too long, the do..while loop should be split
1536 * XXX off into a separate function.
1537 */
1538FILE *
1539http_request_body(struct url *URL, const char *op, struct url_stat *us,
1540	struct url *purl, const char *flags, const char *content_type,
1541	const char *body)
1542{
1543	char timebuf[80];
1544	char hbuf[MAXHOSTNAMELEN + 7], *host;
1545	conn_t *conn;
1546	struct url *url, *new;
1547	int chunked, direct, ims, noredirect, verbose;
1548	int e, i, n, val;
1549	off_t offset, clength, length, size;
1550	time_t mtime;
1551	const char *p;
1552	FILE *f;
1553	hdr_t h;
1554	struct tm *timestruct;
1555	http_headerbuf_t headerbuf;
1556	http_auth_challenges_t server_challenges;
1557	http_auth_challenges_t proxy_challenges;
1558	size_t body_len;
1559
1560	/* The following calls don't allocate anything */
1561	init_http_headerbuf(&headerbuf);
1562	init_http_auth_challenges(&server_challenges);
1563	init_http_auth_challenges(&proxy_challenges);
1564
1565	direct = CHECK_FLAG('d');
1566	noredirect = CHECK_FLAG('A');
1567	verbose = CHECK_FLAG('v');
1568	ims = CHECK_FLAG('i');
1569
1570	if (direct && purl) {
1571		fetchFreeURL(purl);
1572		purl = NULL;
1573	}
1574
1575	/* try the provided URL first */
1576	url = URL;
1577
1578	n = MAX_REDIRECT;
1579	i = 0;
1580
1581	e = HTTP_PROTOCOL_ERROR;
1582	do {
1583		new = NULL;
1584		chunked = 0;
1585		offset = 0;
1586		clength = -1;
1587		length = -1;
1588		size = -1;
1589		mtime = 0;
1590
1591		/* check port */
1592		if (!url->port)
1593			url->port = fetch_default_port(url->scheme);
1594
1595		/* were we redirected to an FTP URL? */
1596		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1597			if (strcmp(op, "GET") == 0)
1598				return (ftp_request(url, "RETR", us, purl, flags));
1599			else if (strcmp(op, "HEAD") == 0)
1600				return (ftp_request(url, "STAT", us, purl, flags));
1601		}
1602
1603		/* connect to server or proxy */
1604		if ((conn = http_connect(url, purl, flags)) == NULL)
1605			goto ouch;
1606
1607		/* append port number only if necessary */
1608		host = url->host;
1609		if (url->port != fetch_default_port(url->scheme)) {
1610			snprintf(hbuf, sizeof(hbuf), "%s:%d", host, url->port);
1611			host = hbuf;
1612		}
1613
1614		/* send request */
1615		if (verbose)
1616			fetch_info("requesting %s://%s%s",
1617			    url->scheme, host, url->doc);
1618		if (purl && strcasecmp(URL->scheme, SCHEME_HTTPS) != 0) {
1619			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1620			    op, url->scheme, host, url->doc);
1621		} else {
1622			http_cmd(conn, "%s %s HTTP/1.1",
1623			    op, url->doc);
1624		}
1625
1626		if (ims && url->ims_time) {
1627			timestruct = gmtime((time_t *)&url->ims_time);
1628			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1629			    timestruct);
1630			if (verbose)
1631				fetch_info("If-Modified-Since: %s", timebuf);
1632			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1633		}
1634		/* virtual host */
1635		http_cmd(conn, "Host: %s", host);
1636
1637		/*
1638		 * Proxy authorization: we only send auth after we received
1639		 * a 407 error. We do not first try basic anyway (changed
1640		 * when support was added for digest-auth)
1641		 */
1642		if (purl && proxy_challenges.valid) {
1643			http_auth_params_t aparams;
1644			init_http_auth_params(&aparams);
1645			if (*purl->user || *purl->pwd) {
1646				aparams.user = strdup(purl->user);
1647				aparams.password = strdup(purl->pwd);
1648			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1649				   *p != '\0') {
1650				if (http_authfromenv(p, &aparams) < 0) {
1651					http_seterr(HTTP_NEED_PROXY_AUTH);
1652					goto ouch;
1653				}
1654			} else if (fetch_netrc_auth(purl) == 0) {
1655				aparams.user = strdup(purl->user);
1656				aparams.password = strdup(purl->pwd);
1657			}
1658			http_authorize(conn, "Proxy-Authorization",
1659				       &proxy_challenges, &aparams, url);
1660			clean_http_auth_params(&aparams);
1661		}
1662
1663		/*
1664		 * Server authorization: we never send "a priori"
1665		 * Basic auth, which used to be done if user/pass were
1666		 * set in the url. This would be weird because we'd send the
1667		 * password in the clear even if Digest is finally to be
1668		 * used (it would have made more sense for the
1669		 * pre-digest version to do this when Basic was specified
1670		 * in the environment)
1671		 */
1672		if (server_challenges.valid) {
1673			http_auth_params_t aparams;
1674			init_http_auth_params(&aparams);
1675			if (*url->user || *url->pwd) {
1676				aparams.user = strdup(url->user);
1677				aparams.password = strdup(url->pwd);
1678			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1679				   *p != '\0') {
1680				if (http_authfromenv(p, &aparams) < 0) {
1681					http_seterr(HTTP_NEED_AUTH);
1682					goto ouch;
1683				}
1684			} else if (fetch_netrc_auth(url) == 0) {
1685				aparams.user = strdup(url->user);
1686				aparams.password = strdup(url->pwd);
1687			} else if (fetchAuthMethod &&
1688				   fetchAuthMethod(url) == 0) {
1689				aparams.user = strdup(url->user);
1690				aparams.password = strdup(url->pwd);
1691			} else {
1692				http_seterr(HTTP_NEED_AUTH);
1693				goto ouch;
1694			}
1695			http_authorize(conn, "Authorization",
1696				       &server_challenges, &aparams, url);
1697			clean_http_auth_params(&aparams);
1698		}
1699
1700		/* other headers */
1701		if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1702			if (*p != '\0')
1703				http_cmd(conn, "Accept: %s", p);
1704		} else {
1705			http_cmd(conn, "Accept: */*");
1706		}
1707		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1708			if (strcasecmp(p, "auto") == 0)
1709				http_cmd(conn, "Referer: %s://%s%s",
1710				    url->scheme, host, url->doc);
1711			else
1712				http_cmd(conn, "Referer: %s", p);
1713		}
1714		if ((p = getenv("HTTP_USER_AGENT")) != NULL) {
1715			/* no User-Agent if defined but empty */
1716			if  (*p != '\0')
1717				http_cmd(conn, "User-Agent: %s", p);
1718		} else {
1719			/* default User-Agent */
1720			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER,
1721			    getprogname());
1722		}
1723		if (url->offset > 0)
1724			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1725		http_cmd(conn, "Connection: close");
1726
1727		if (body) {
1728			body_len = strlen(body);
1729			http_cmd(conn, "Content-Length: %zu", body_len);
1730			if (content_type != NULL)
1731				http_cmd(conn, "Content-Type: %s", content_type);
1732		}
1733
1734		http_cmd(conn, "");
1735
1736		if (body)
1737			fetch_write(conn, body, body_len);
1738
1739		/*
1740		 * Force the queued request to be dispatched.  Normally, one
1741		 * would do this with shutdown(2) but squid proxies can be
1742		 * configured to disallow such half-closed connections.  To
1743		 * be compatible with such configurations, fiddle with socket
1744		 * options to force the pending data to be written.
1745		 */
1746		val = 0;
1747		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1748			   sizeof(val));
1749		val = 1;
1750		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1751			   sizeof(val));
1752
1753		/* get reply */
1754		switch (http_get_reply(conn)) {
1755		case HTTP_OK:
1756		case HTTP_PARTIAL:
1757		case HTTP_NOT_MODIFIED:
1758			/* fine */
1759			break;
1760		case HTTP_MOVED_PERM:
1761		case HTTP_MOVED_TEMP:
1762		case HTTP_TEMP_REDIRECT:
1763		case HTTP_PERM_REDIRECT:
1764		case HTTP_SEE_OTHER:
1765		case HTTP_USE_PROXY:
1766			/*
1767			 * Not so fine, but we still have to read the
1768			 * headers to get the new location.
1769			 */
1770			break;
1771		case HTTP_NEED_AUTH:
1772			if (server_challenges.valid) {
1773				/*
1774				 * We already sent out authorization code,
1775				 * so there's nothing more we can do.
1776				 */
1777				http_seterr(conn->err);
1778				goto ouch;
1779			}
1780			/* try again, but send the password this time */
1781			if (verbose)
1782				fetch_info("server requires authorization");
1783			break;
1784		case HTTP_NEED_PROXY_AUTH:
1785			if (proxy_challenges.valid) {
1786				/*
1787				 * We already sent our proxy
1788				 * authorization code, so there's
1789				 * nothing more we can do. */
1790				http_seterr(conn->err);
1791				goto ouch;
1792			}
1793			/* try again, but send the password this time */
1794			if (verbose)
1795				fetch_info("proxy requires authorization");
1796			break;
1797		case HTTP_BAD_RANGE:
1798			/*
1799			 * This can happen if we ask for 0 bytes because
1800			 * we already have the whole file.  Consider this
1801			 * a success for now, and check sizes later.
1802			 */
1803			break;
1804		case HTTP_PROTOCOL_ERROR:
1805			/* fall through */
1806		case -1:
1807			fetch_syserr();
1808			goto ouch;
1809		default:
1810			http_seterr(conn->err);
1811			if (!verbose)
1812				goto ouch;
1813			/* fall through so we can get the full error message */
1814		}
1815
1816		/* get headers. http_next_header expects one line readahead */
1817		if (fetch_getln(conn) == -1) {
1818			fetch_syserr();
1819			goto ouch;
1820		}
1821		do {
1822			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1823			case hdr_syserror:
1824				fetch_syserr();
1825				goto ouch;
1826			case hdr_error:
1827				http_seterr(HTTP_PROTOCOL_ERROR);
1828				goto ouch;
1829			case hdr_content_length:
1830				http_parse_length(p, &clength);
1831				break;
1832			case hdr_content_range:
1833				http_parse_range(p, &offset, &length, &size);
1834				break;
1835			case hdr_last_modified:
1836				http_parse_mtime(p, &mtime);
1837				break;
1838			case hdr_location:
1839				if (!HTTP_REDIRECT(conn->err))
1840					break;
1841				/*
1842				 * if the A flag is set, we don't follow
1843				 * temporary redirects.
1844				 */
1845				if (noredirect &&
1846				    conn->err != HTTP_MOVED_PERM &&
1847				    conn->err != HTTP_PERM_REDIRECT &&
1848				    conn->err != HTTP_USE_PROXY) {
1849					n = 1;
1850					break;
1851				}
1852				if (new)
1853					free(new);
1854				if (verbose)
1855					fetch_info("%d redirect to %s",
1856					    conn->err, p);
1857				if (*p == '/')
1858					/* absolute path */
1859					new = fetchMakeURL(url->scheme, url->host,
1860					    url->port, p, url->user, url->pwd);
1861				else
1862					new = fetchParseURL(p);
1863				if (new == NULL) {
1864					/* XXX should set an error code */
1865					DEBUGF("failed to parse new URL\n");
1866					goto ouch;
1867				}
1868
1869				/* Only copy credentials if the host matches */
1870				if (strcmp(new->host, url->host) == 0 &&
1871				    !*new->user && !*new->pwd) {
1872					strcpy(new->user, url->user);
1873					strcpy(new->pwd, url->pwd);
1874				}
1875				new->offset = url->offset;
1876				new->length = url->length;
1877				new->ims_time = url->ims_time;
1878				break;
1879			case hdr_transfer_encoding:
1880				/* XXX weak test*/
1881				chunked = (strcasecmp(p, "chunked") == 0);
1882				break;
1883			case hdr_www_authenticate:
1884				if (conn->err != HTTP_NEED_AUTH)
1885					break;
1886				if (http_parse_authenticate(p, &server_challenges) == 0)
1887					++n;
1888				break;
1889			case hdr_proxy_authenticate:
1890				if (conn->err != HTTP_NEED_PROXY_AUTH)
1891					break;
1892				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1893					++n;
1894				break;
1895			case hdr_end:
1896				/* fall through */
1897			case hdr_unknown:
1898				/* ignore */
1899				break;
1900			}
1901		} while (h > hdr_end);
1902
1903		/* we need to provide authentication */
1904		if (conn->err == HTTP_NEED_AUTH ||
1905		    conn->err == HTTP_NEED_PROXY_AUTH) {
1906			e = conn->err;
1907			if ((conn->err == HTTP_NEED_AUTH &&
1908			     !server_challenges.valid) ||
1909			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1910			     !proxy_challenges.valid)) {
1911				/* 401/7 but no www/proxy-authenticate ?? */
1912				DEBUGF("%03d without auth header\n", conn->err);
1913				goto ouch;
1914			}
1915			fetch_close(conn);
1916			conn = NULL;
1917			continue;
1918		}
1919
1920		/* requested range not satisfiable */
1921		if (conn->err == HTTP_BAD_RANGE) {
1922			if (url->offset > 0 && url->length == 0) {
1923				/* asked for 0 bytes; fake it */
1924				offset = url->offset;
1925				clength = -1;
1926				conn->err = HTTP_OK;
1927				break;
1928			} else {
1929				http_seterr(conn->err);
1930				goto ouch;
1931			}
1932		}
1933
1934		/* we have a hit or an error */
1935		if (conn->err == HTTP_OK
1936		    || conn->err == HTTP_NOT_MODIFIED
1937		    || conn->err == HTTP_PARTIAL
1938		    || HTTP_ERROR(conn->err))
1939			break;
1940
1941		/* all other cases: we got a redirect */
1942		e = conn->err;
1943		clean_http_auth_challenges(&server_challenges);
1944		fetch_close(conn);
1945		conn = NULL;
1946		if (!new) {
1947			DEBUGF("redirect with no new location\n");
1948			break;
1949		}
1950		if (url != URL)
1951			fetchFreeURL(url);
1952		url = new;
1953	} while (++i < n);
1954
1955	/* we failed, or ran out of retries */
1956	if (conn == NULL) {
1957		http_seterr(e);
1958		goto ouch;
1959	}
1960
1961	DEBUGF("offset %lld, length %lld, size %lld, clength %lld\n",
1962	    (long long)offset, (long long)length,
1963	    (long long)size, (long long)clength);
1964
1965	if (conn->err == HTTP_NOT_MODIFIED) {
1966		http_seterr(HTTP_NOT_MODIFIED);
1967		return (NULL);
1968	}
1969
1970	/* check for inconsistencies */
1971	if (clength != -1 && length != -1 && clength != length) {
1972		http_seterr(HTTP_PROTOCOL_ERROR);
1973		goto ouch;
1974	}
1975	if (clength == -1)
1976		clength = length;
1977	if (clength != -1)
1978		length = offset + clength;
1979	if (length != -1 && size != -1 && length != size) {
1980		http_seterr(HTTP_PROTOCOL_ERROR);
1981		goto ouch;
1982	}
1983	if (size == -1)
1984		size = length;
1985
1986	/* fill in stats */
1987	if (us) {
1988		us->size = size;
1989		us->atime = us->mtime = mtime;
1990	}
1991
1992	/* too far? */
1993	if (URL->offset > 0 && offset > URL->offset) {
1994		http_seterr(HTTP_PROTOCOL_ERROR);
1995		goto ouch;
1996	}
1997
1998	/* report back real offset and size */
1999	URL->offset = offset;
2000	URL->length = clength;
2001
2002	/* wrap it up in a FILE */
2003	if ((f = http_funopen(conn, chunked)) == NULL) {
2004		fetch_syserr();
2005		goto ouch;
2006	}
2007
2008	if (url != URL)
2009		fetchFreeURL(url);
2010	if (purl)
2011		fetchFreeURL(purl);
2012
2013	if (HTTP_ERROR(conn->err)) {
2014		http_print_html(stderr, f);
2015		fclose(f);
2016		f = NULL;
2017	}
2018	clean_http_headerbuf(&headerbuf);
2019	clean_http_auth_challenges(&server_challenges);
2020	clean_http_auth_challenges(&proxy_challenges);
2021	return (f);
2022
2023ouch:
2024	if (url != URL)
2025		fetchFreeURL(url);
2026	if (purl)
2027		fetchFreeURL(purl);
2028	if (conn != NULL)
2029		fetch_close(conn);
2030	clean_http_headerbuf(&headerbuf);
2031	clean_http_auth_challenges(&server_challenges);
2032	clean_http_auth_challenges(&proxy_challenges);
2033	return (NULL);
2034}
2035
2036
2037/*****************************************************************************
2038 * Entry points
2039 */
2040
2041/*
2042 * Retrieve and stat a file by HTTP
2043 */
2044FILE *
2045fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
2046{
2047	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
2048}
2049
2050/*
2051 * Retrieve a file by HTTP
2052 */
2053FILE *
2054fetchGetHTTP(struct url *URL, const char *flags)
2055{
2056	return (fetchXGetHTTP(URL, NULL, flags));
2057}
2058
2059/*
2060 * Store a file by HTTP
2061 */
2062FILE *
2063fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2064{
2065	warnx("fetchPutHTTP(): not implemented");
2066	return (NULL);
2067}
2068
2069/*
2070 * Get an HTTP document's metadata
2071 */
2072int
2073fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2074{
2075	FILE *f;
2076
2077	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2078	if (f == NULL)
2079		return (-1);
2080	fclose(f);
2081	return (0);
2082}
2083
2084/*
2085 * List a directory
2086 */
2087struct url_ent *
2088fetchListHTTP(struct url *url __unused, const char *flags __unused)
2089{
2090	warnx("fetchListHTTP(): not implemented");
2091	return (NULL);
2092}
2093
2094FILE *
2095fetchReqHTTP(struct url *URL, const char *method, const char *flags,
2096	const char *content_type, const char *body)
2097{
2098
2099	return (http_request_body(URL, method, NULL, http_get_proxy(URL, flags),
2100	    flags, content_type, body));
2101}
2102