1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2000-2014 Dag-Erling Sm��rgrav
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer
12 *    in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
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 <stdbool.h>
75#include <stdio.h>
76#include <stdlib.h>
77#include <string.h>
78#include <time.h>
79#include <unistd.h>
80
81#ifdef WITH_SSL
82#include <openssl/md5.h>
83#define MD5Init(c) MD5_Init(c)
84#define MD5Update(c, data, len) MD5_Update(c, data, len)
85#define MD5Final(md, c) MD5_Final(md, c)
86#else
87#include <md5.h>
88#endif
89
90#include <netinet/in.h>
91#include <netinet/tcp.h>
92
93#include "fetch.h"
94#include "common.h"
95#include "httperr.h"
96
97/* Maximum number of redirects to follow */
98#define MAX_REDIRECT 20
99
100/* Symbolic names for reply codes we care about */
101#define HTTP_OK			200
102#define HTTP_PARTIAL		206
103#define HTTP_MOVED_PERM		301
104#define HTTP_MOVED_TEMP		302
105#define HTTP_SEE_OTHER		303
106#define HTTP_NOT_MODIFIED	304
107#define HTTP_USE_PROXY		305
108#define HTTP_TEMP_REDIRECT	307
109#define HTTP_PERM_REDIRECT	308
110#define HTTP_NEED_AUTH		401
111#define HTTP_NEED_PROXY_AUTH	407
112#define HTTP_BAD_RANGE		416
113#define HTTP_PROTOCOL_ERROR	999
114
115#define HTTP_REDIRECT(xyz) ((xyz) == HTTP_MOVED_PERM \
116			    || (xyz) == HTTP_MOVED_TEMP \
117			    || (xyz) == HTTP_TEMP_REDIRECT \
118			    || (xyz) == HTTP_PERM_REDIRECT \
119			    || (xyz) == HTTP_USE_PROXY \
120			    || (xyz) == HTTP_SEE_OTHER)
121
122#define HTTP_ERROR(xyz) ((xyz) >= 400 && (xyz) <= 599)
123
124
125/*****************************************************************************
126 * I/O functions for decoding chunked streams
127 */
128
129struct httpio
130{
131	conn_t		*conn;		/* connection */
132	int		 chunked;	/* chunked mode */
133	char		*buf;		/* chunk buffer */
134	size_t		 bufsize;	/* size of chunk buffer */
135	size_t		 buflen;	/* amount of data currently in buffer */
136	size_t		 bufpos;	/* current read offset in buffer */
137	int		 eof;		/* end-of-file flag */
138	int		 error;		/* error flag */
139	size_t		 chunksize;	/* remaining size of current chunk */
140#ifndef NDEBUG
141	size_t		 total;
142#endif
143};
144
145/*
146 * Get next chunk header
147 */
148static int
149http_new_chunk(struct httpio *io)
150{
151	char *p;
152
153	if (fetch_getln(io->conn) == -1)
154		return (-1);
155
156	if (io->conn->buflen < 2 || !isxdigit((unsigned char)*io->conn->buf))
157		return (-1);
158
159	for (p = io->conn->buf; *p && !isspace((unsigned char)*p); ++p) {
160		if (*p == ';')
161			break;
162		if (!isxdigit((unsigned char)*p))
163			return (-1);
164		if (isdigit((unsigned char)*p)) {
165			io->chunksize = io->chunksize * 16 +
166			    *p - '0';
167		} else {
168			io->chunksize = io->chunksize * 16 +
169			    10 + tolower((unsigned char)*p) - 'a';
170		}
171	}
172
173#ifndef NDEBUG
174	if (fetchDebug) {
175		io->total += io->chunksize;
176		if (io->chunksize == 0)
177			fprintf(stderr, "%s(): end of last chunk\n", __func__);
178		else
179			fprintf(stderr, "%s(): new chunk: %lu (%lu)\n",
180			    __func__, (unsigned long)io->chunksize,
181			    (unsigned long)io->total);
182	}
183#endif
184
185	return (io->chunksize);
186}
187
188/*
189 * Grow the input buffer to at least len bytes
190 */
191static inline int
192http_growbuf(struct httpio *io, size_t len)
193{
194	char *tmp;
195
196	if (io->bufsize >= len)
197		return (0);
198
199	if ((tmp = realloc(io->buf, len)) == NULL)
200		return (-1);
201	io->buf = tmp;
202	io->bufsize = len;
203	return (0);
204}
205
206/*
207 * Fill the input buffer, do chunk decoding on the fly
208 */
209static ssize_t
210http_fillbuf(struct httpio *io, size_t len)
211{
212	ssize_t nbytes;
213	char ch;
214
215	if (io->error)
216		return (-1);
217	if (io->eof)
218		return (0);
219
220	/* not chunked: just fetch the requested amount */
221	if (io->chunked == 0) {
222		if (http_growbuf(io, len) == -1)
223			return (-1);
224		if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
225			io->error = errno;
226			return (-1);
227		}
228		io->buflen = nbytes;
229		io->bufpos = 0;
230		return (io->buflen);
231	}
232
233	/* chunked, but we ran out: get the next chunk header */
234	if (io->chunksize == 0) {
235		switch (http_new_chunk(io)) {
236		case -1:
237			io->error = EPROTO;
238			return (-1);
239		case 0:
240			io->eof = 1;
241			return (0);
242		}
243	}
244
245	/* fetch the requested amount, but no more than the current chunk */
246	if (len > io->chunksize)
247		len = io->chunksize;
248	if (http_growbuf(io, len) == -1)
249		return (-1);
250	if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
251		io->error = errno;
252		return (-1);
253	}
254	io->bufpos = 0;
255	io->buflen = nbytes;
256	io->chunksize -= nbytes;
257
258	if (io->chunksize == 0) {
259		if (fetch_read(io->conn, &ch, 1) != 1 || ch != '\r' ||
260		    fetch_read(io->conn, &ch, 1) != 1 || ch != '\n')
261			return (-1);
262	}
263
264	return (io->buflen);
265}
266
267/*
268 * Read function
269 */
270static int
271http_readfn(void *v, char *buf, int len)
272{
273	struct httpio *io = (struct httpio *)v;
274	int rlen;
275
276	if (io->error)
277		return (-1);
278	if (io->eof)
279		return (0);
280
281	/* empty buffer */
282	if (!io->buf || io->bufpos == io->buflen) {
283		if ((rlen = http_fillbuf(io, len)) < 0) {
284			if ((errno = io->error) == EINTR)
285				io->error = 0;
286			return (-1);
287		} else if (rlen == 0) {
288			return (0);
289		}
290	}
291
292	rlen = io->buflen - io->bufpos;
293	if (len < rlen)
294		rlen = len;
295	memcpy(buf, io->buf + io->bufpos, rlen);
296	io->bufpos += rlen;
297	return (rlen);
298}
299
300/*
301 * Write function
302 */
303static int
304http_writefn(void *v, const char *buf, int len)
305{
306	struct httpio *io = (struct httpio *)v;
307
308	return (fetch_write(io->conn, buf, len));
309}
310
311/*
312 * Close function
313 */
314static int
315http_closefn(void *v)
316{
317	struct httpio *io = (struct httpio *)v;
318	int r;
319
320	r = fetch_close(io->conn);
321	if (io->buf)
322		free(io->buf);
323	free(io);
324	return (r);
325}
326
327/*
328 * Wrap a file descriptor up
329 */
330static FILE *
331http_funopen(conn_t *conn, int chunked)
332{
333	struct httpio *io;
334	FILE *f;
335
336	if ((io = calloc(1, sizeof(*io))) == NULL) {
337		fetch_syserr();
338		return (NULL);
339	}
340	io->conn = conn;
341	io->chunked = chunked;
342	f = funopen(io, http_readfn, http_writefn, NULL, http_closefn);
343	if (f == NULL) {
344		fetch_syserr();
345		free(io);
346		return (NULL);
347	}
348	return (f);
349}
350
351
352/*****************************************************************************
353 * Helper functions for talking to the server and parsing its replies
354 */
355
356/* Header types */
357typedef enum {
358	hdr_syserror = -2,
359	hdr_error = -1,
360	hdr_end = 0,
361	hdr_unknown = 1,
362	hdr_content_length,
363	hdr_content_range,
364	hdr_last_modified,
365	hdr_location,
366	hdr_transfer_encoding,
367	hdr_www_authenticate,
368	hdr_proxy_authenticate,
369} hdr_t;
370
371/* Names of interesting headers */
372static struct {
373	hdr_t		 num;
374	const char	*name;
375} hdr_names[] = {
376	{ hdr_content_length,		"Content-Length" },
377	{ hdr_content_range,		"Content-Range" },
378	{ hdr_last_modified,		"Last-Modified" },
379	{ hdr_location,			"Location" },
380	{ hdr_transfer_encoding,	"Transfer-Encoding" },
381	{ hdr_www_authenticate,		"WWW-Authenticate" },
382	{ hdr_proxy_authenticate,	"Proxy-Authenticate" },
383	{ hdr_unknown,			NULL },
384};
385
386/*
387 * Send a formatted line; optionally echo to terminal
388 */
389static int
390http_cmd(conn_t *conn, const char *fmt, ...)
391{
392	va_list ap;
393	size_t len;
394	char *msg;
395	int r;
396
397	va_start(ap, fmt);
398	len = vasprintf(&msg, fmt, ap);
399	va_end(ap);
400
401	if (msg == NULL) {
402		errno = ENOMEM;
403		fetch_syserr();
404		return (-1);
405	}
406
407	r = fetch_putln(conn, msg, len);
408	free(msg);
409
410	if (r == -1) {
411		fetch_syserr();
412		return (-1);
413	}
414
415	return (0);
416}
417
418/*
419 * Get and parse status line
420 */
421static int
422http_get_reply(conn_t *conn)
423{
424	char *p;
425
426	if (fetch_getln(conn) == -1)
427		return (-1);
428	/*
429	 * A valid status line looks like "HTTP/m.n xyz reason" where m
430	 * and n are the major and minor protocol version numbers and xyz
431	 * is the reply code.
432	 * Unfortunately, there are servers out there (NCSA 1.5.1, to name
433	 * just one) that do not send a version number, so we can't rely
434	 * on finding one, but if we do, insist on it being 1.0 or 1.1.
435	 * We don't care about the reason phrase.
436	 */
437	if (strncmp(conn->buf, "HTTP", 4) != 0)
438		return (HTTP_PROTOCOL_ERROR);
439	p = conn->buf + 4;
440	if (*p == '/') {
441		if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
442			return (HTTP_PROTOCOL_ERROR);
443		p += 4;
444	}
445	if (*p != ' ' ||
446	    !isdigit((unsigned char)p[1]) ||
447	    !isdigit((unsigned char)p[2]) ||
448	    !isdigit((unsigned char)p[3]))
449		return (HTTP_PROTOCOL_ERROR);
450
451	conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
452	return (conn->err);
453}
454
455/*
456 * Check a header; if the type matches the given string, return a pointer
457 * to the beginning of the value.
458 */
459static const char *
460http_match(const char *str, const char *hdr)
461{
462	while (*str && *hdr &&
463	    tolower((unsigned char)*str++) == tolower((unsigned char)*hdr++))
464		/* nothing */;
465	if (*str || *hdr != ':')
466		return (NULL);
467	while (*hdr && isspace((unsigned char)*++hdr))
468		/* nothing */;
469	return (hdr);
470}
471
472
473/*
474 * Get the next header and return the appropriate symbolic code.  We
475 * need to read one line ahead for checking for a continuation line
476 * belonging to the current header (continuation lines start with
477 * white space).
478 *
479 * We get called with a fresh line already in the conn buffer, either
480 * from the previous http_next_header() invocation, or, the first
481 * time, from a fetch_getln() performed by our caller.
482 *
483 * This stops when we encounter an empty line (we dont read beyond the header
484 * area).
485 *
486 * Note that the "headerbuf" is just a place to return the result. Its
487 * contents are not used for the next call. This means that no cleanup
488 * is needed when ie doing another connection, just call the cleanup when
489 * fully done to deallocate memory.
490 */
491
492/* Limit the max number of continuation lines to some reasonable value */
493#define HTTP_MAX_CONT_LINES 10
494
495/* Place into which to build a header from one or several lines */
496typedef struct {
497	char	*buf;		/* buffer */
498	size_t	 bufsize;	/* buffer size */
499	size_t	 buflen;	/* length of buffer contents */
500} http_headerbuf_t;
501
502static void
503init_http_headerbuf(http_headerbuf_t *buf)
504{
505	buf->buf = NULL;
506	buf->bufsize = 0;
507	buf->buflen = 0;
508}
509
510static void
511clean_http_headerbuf(http_headerbuf_t *buf)
512{
513	if (buf->buf)
514		free(buf->buf);
515	init_http_headerbuf(buf);
516}
517
518/* Remove whitespace at the end of the buffer */
519static void
520http_conn_trimright(conn_t *conn)
521{
522	while (conn->buflen &&
523	       isspace((unsigned char)conn->buf[conn->buflen - 1]))
524		conn->buflen--;
525	conn->buf[conn->buflen] = '\0';
526}
527
528static hdr_t
529http_next_header(conn_t *conn, http_headerbuf_t *hbuf, const char **p)
530{
531	unsigned int i, len;
532
533	/*
534	 * Have to do the stripping here because of the first line. So
535	 * it's done twice for the subsequent lines. No big deal
536	 */
537	http_conn_trimright(conn);
538	if (conn->buflen == 0)
539		return (hdr_end);
540
541	/* Copy the line to the headerbuf */
542	if (hbuf->bufsize < conn->buflen + 1) {
543		if ((hbuf->buf = realloc(hbuf->buf, conn->buflen + 1)) == NULL)
544			return (hdr_syserror);
545		hbuf->bufsize = conn->buflen + 1;
546	}
547	strcpy(hbuf->buf, conn->buf);
548	hbuf->buflen = conn->buflen;
549
550	/*
551	 * Fetch possible continuation lines. Stop at 1st non-continuation
552	 * and leave it in the conn buffer
553	 */
554	for (i = 0; i < HTTP_MAX_CONT_LINES; i++) {
555		if (fetch_getln(conn) == -1)
556			return (hdr_syserror);
557
558		/*
559		 * Note: we carry on the idea from the previous version
560		 * that a pure whitespace line is equivalent to an empty
561		 * one (so it's not continuation and will be handled when
562		 * we are called next)
563		 */
564		http_conn_trimright(conn);
565		if (conn->buf[0] != ' ' && conn->buf[0] != "\t"[0])
566			break;
567
568		/* Got a continuation line. Concatenate to previous */
569		len = hbuf->buflen + conn->buflen;
570		if (hbuf->bufsize < len + 1) {
571			len *= 2;
572			if ((hbuf->buf = realloc(hbuf->buf, len + 1)) == NULL)
573				return (hdr_syserror);
574			hbuf->bufsize = len + 1;
575		}
576		strcpy(hbuf->buf + hbuf->buflen, conn->buf);
577		hbuf->buflen += conn->buflen;
578	}
579
580	/*
581	 * We could check for malformed headers but we don't really care.
582	 * A valid header starts with a token immediately followed by a
583	 * colon; a token is any sequence of non-control, non-whitespace
584	 * characters except "()<>@,;:\\\"{}".
585	 */
586	for (i = 0; hdr_names[i].num != hdr_unknown; i++)
587		if ((*p = http_match(hdr_names[i].name, hbuf->buf)) != NULL)
588			return (hdr_names[i].num);
589
590	return (hdr_unknown);
591}
592
593/**************************
594 * [Proxy-]Authenticate header parsing
595 */
596
597/*
598 * Read doublequote-delimited string into output buffer obuf (allocated
599 * by caller, whose responsibility it is to ensure that it's big enough)
600 * cp points to the first char after the initial '"'
601 * Handles \ quoting
602 * Returns pointer to the first char after the terminating double quote, or
603 * NULL for error.
604 */
605static const char *
606http_parse_headerstring(const char *cp, char *obuf)
607{
608	for (;;) {
609		switch (*cp) {
610		case 0: /* Unterminated string */
611			*obuf = 0;
612			return (NULL);
613		case '"': /* Ending quote */
614			*obuf = 0;
615			return (++cp);
616		case '\\':
617			if (*++cp == 0) {
618				*obuf = 0;
619				return (NULL);
620			}
621			/* FALLTHROUGH */
622		default:
623			*obuf++ = *cp++;
624		}
625	}
626}
627
628/* Http auth challenge schemes */
629typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
630
631/* Data holder for a Basic or Digest challenge. */
632typedef struct {
633	http_auth_schemes_t scheme;
634	char	*realm;
635	char	*qop;
636	char	*nonce;
637	char	*opaque;
638	char	*algo;
639	int	 stale;
640	int	 nc; /* Nonce count */
641} http_auth_challenge_t;
642
643static void
644init_http_auth_challenge(http_auth_challenge_t *b)
645{
646	b->scheme = HTTPAS_UNKNOWN;
647	b->realm = b->qop = b->nonce = b->opaque = b->algo = NULL;
648	b->stale = b->nc = 0;
649}
650
651static void
652clean_http_auth_challenge(http_auth_challenge_t *b)
653{
654	if (b->realm)
655		free(b->realm);
656	if (b->qop)
657		free(b->qop);
658	if (b->nonce)
659		free(b->nonce);
660	if (b->opaque)
661		free(b->opaque);
662	if (b->algo)
663		free(b->algo);
664	init_http_auth_challenge(b);
665}
666
667/* Data holder for an array of challenges offered in an http response. */
668#define MAX_CHALLENGES 10
669typedef struct {
670	http_auth_challenge_t *challenges[MAX_CHALLENGES];
671	int	count; /* Number of parsed challenges in the array */
672	int	valid; /* We did parse an authenticate header */
673} http_auth_challenges_t;
674
675static void
676init_http_auth_challenges(http_auth_challenges_t *cs)
677{
678	int i;
679	for (i = 0; i < MAX_CHALLENGES; i++)
680		cs->challenges[i] = NULL;
681	cs->count = cs->valid = 0;
682}
683
684static void
685clean_http_auth_challenges(http_auth_challenges_t *cs)
686{
687	int i;
688	/* We rely on non-zero pointers being allocated, not on the count */
689	for (i = 0; i < MAX_CHALLENGES; i++) {
690		if (cs->challenges[i] != NULL) {
691			clean_http_auth_challenge(cs->challenges[i]);
692			free(cs->challenges[i]);
693		}
694	}
695	init_http_auth_challenges(cs);
696}
697
698/*
699 * Enumeration for lexical elements. Separators will be returned as their own
700 * ascii value
701 */
702typedef enum {HTTPHL_WORD=256, HTTPHL_STRING=257, HTTPHL_END=258,
703	      HTTPHL_ERROR = 259} http_header_lex_t;
704
705/*
706 * Determine what kind of token comes next and return possible value
707 * in buf, which is supposed to have been allocated big enough by
708 * caller. Advance input pointer and return element type.
709 */
710static int
711http_header_lex(const char **cpp, char *buf)
712{
713	size_t l;
714	/* Eat initial whitespace */
715	*cpp += strspn(*cpp, " \t");
716	if (**cpp == 0)
717		return (HTTPHL_END);
718
719	/* Separator ? */
720	if (**cpp == ',' || **cpp == '=')
721		return (*((*cpp)++));
722
723	/* String ? */
724	if (**cpp == '"') {
725		*cpp = http_parse_headerstring(++*cpp, buf);
726		if (*cpp == NULL)
727			return (HTTPHL_ERROR);
728		return (HTTPHL_STRING);
729	}
730
731	/* Read other token, until separator or whitespace */
732	l = strcspn(*cpp, " \t,=");
733	memcpy(buf, *cpp, l);
734	buf[l] = 0;
735	*cpp += l;
736	return (HTTPHL_WORD);
737}
738
739/*
740 * Read challenges from http xxx-authenticate header and accumulate them
741 * in the challenges list structure.
742 *
743 * Headers with multiple challenges are specified by rfc2617, but
744 * servers (ie: squid) often send them in separate headers instead,
745 * which in turn is forbidden by the http spec (multiple headers with
746 * the same name are only allowed for pure comma-separated lists, see
747 * rfc2616 sec 4.2).
748 *
749 * We support both approaches anyway
750 */
751static int
752http_parse_authenticate(const char *cp, http_auth_challenges_t *cs)
753{
754	int ret = -1;
755	http_header_lex_t lex;
756	char *key = malloc(strlen(cp) + 1);
757	char *value = malloc(strlen(cp) + 1);
758	char *buf = malloc(strlen(cp) + 1);
759
760	if (key == NULL || value == NULL || buf == NULL) {
761		fetch_syserr();
762		goto out;
763	}
764
765	/* In any case we've seen the header and we set the valid bit */
766	cs->valid = 1;
767
768	/* Need word first */
769	lex = http_header_lex(&cp, key);
770	if (lex != HTTPHL_WORD)
771		goto out;
772
773	/* Loop on challenges */
774	for (; cs->count < MAX_CHALLENGES; cs->count++) {
775		cs->challenges[cs->count] =
776			malloc(sizeof(http_auth_challenge_t));
777		if (cs->challenges[cs->count] == NULL) {
778			fetch_syserr();
779			goto out;
780		}
781		init_http_auth_challenge(cs->challenges[cs->count]);
782		if (strcasecmp(key, "basic") == 0) {
783			cs->challenges[cs->count]->scheme = HTTPAS_BASIC;
784		} else if (strcasecmp(key, "digest") == 0) {
785			cs->challenges[cs->count]->scheme = HTTPAS_DIGEST;
786		} else {
787			cs->challenges[cs->count]->scheme = HTTPAS_UNKNOWN;
788			/*
789			 * Continue parsing as basic or digest may
790			 * follow, and the syntax is the same for
791			 * all. We'll just ignore this one when
792			 * looking at the list
793			 */
794		}
795
796		/* Loop on attributes */
797		for (;;) {
798			/* Key */
799			lex = http_header_lex(&cp, key);
800			if (lex != HTTPHL_WORD)
801				goto out;
802
803			/* Equal sign */
804			lex = http_header_lex(&cp, buf);
805			if (lex != '=')
806				goto out;
807
808			/* Value */
809			lex = http_header_lex(&cp, value);
810			if (lex != HTTPHL_WORD && lex != HTTPHL_STRING)
811				goto out;
812
813			if (strcasecmp(key, "realm") == 0) {
814				cs->challenges[cs->count]->realm =
815				    strdup(value);
816			} else if (strcasecmp(key, "qop") == 0) {
817				cs->challenges[cs->count]->qop =
818				    strdup(value);
819			} else if (strcasecmp(key, "nonce") == 0) {
820				cs->challenges[cs->count]->nonce =
821				    strdup(value);
822			} else if (strcasecmp(key, "opaque") == 0) {
823				cs->challenges[cs->count]->opaque =
824				    strdup(value);
825			} else if (strcasecmp(key, "algorithm") == 0) {
826				cs->challenges[cs->count]->algo =
827				    strdup(value);
828			} else if (strcasecmp(key, "stale") == 0) {
829				cs->challenges[cs->count]->stale =
830				    strcasecmp(value, "no");
831			} else {
832				/* ignore unknown attributes */
833			}
834
835			/* Comma or Next challenge or End */
836			lex = http_header_lex(&cp, key);
837			/*
838			 * If we get a word here, this is the beginning of the
839			 * next challenge. Break the attributes loop
840			 */
841			if (lex == HTTPHL_WORD)
842				break;
843
844			if (lex == HTTPHL_END) {
845				/* End while looking for ',' is normal exit */
846				cs->count++;
847				ret = 0;
848				goto out;
849			}
850			/* Anything else is an error */
851			if (lex != ',')
852				goto out;
853
854		} /* End attributes loop */
855	} /* End challenge loop */
856
857	/*
858	 * Challenges max count exceeded. This really can't happen
859	 * with normal data, something's fishy -> error
860	 */
861
862out:
863	if (key)
864		free(key);
865	if (value)
866		free(value);
867	if (buf)
868		free(buf);
869	return (ret);
870}
871
872
873/*
874 * Parse a last-modified header
875 */
876static int
877http_parse_mtime(const char *p, time_t *mtime)
878{
879	char locale[64], *r;
880	struct tm tm;
881
882	strlcpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
883	setlocale(LC_TIME, "C");
884	r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
885	/*
886	 * Some proxies use UTC in response, but it should still be
887	 * parsed. RFC2616 states GMT and UTC are exactly equal for HTTP.
888	 */
889	if (r == NULL)
890		r = strptime(p, "%a, %d %b %Y %H:%M:%S UTC", &tm);
891	/* XXX should add support for date-2 and date-3 */
892	setlocale(LC_TIME, locale);
893	if (r == NULL)
894		return (-1);
895	DEBUGF("last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
896	    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
897	    tm.tm_hour, tm.tm_min, tm.tm_sec);
898	*mtime = timegm(&tm);
899	return (0);
900}
901
902/*
903 * Parse a content-length header
904 */
905static int
906http_parse_length(const char *p, off_t *length)
907{
908	off_t len;
909
910	for (len = 0; *p && isdigit((unsigned char)*p); ++p)
911		len = len * 10 + (*p - '0');
912	if (*p)
913		return (-1);
914	DEBUGF("content length: [%lld]\n", (long long)len);
915	*length = len;
916	return (0);
917}
918
919/*
920 * Parse a content-range header
921 */
922static int
923http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
924{
925	off_t first, last, len;
926
927	if (strncasecmp(p, "bytes ", 6) != 0)
928		return (-1);
929	p += 6;
930	if (*p == '*') {
931		first = last = -1;
932		++p;
933	} else {
934		for (first = 0; *p && isdigit((unsigned char)*p); ++p)
935			first = first * 10 + *p - '0';
936		if (*p != '-')
937			return (-1);
938		for (last = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
939			last = last * 10 + *p - '0';
940	}
941	if (first > last || *p != '/')
942		return (-1);
943	for (len = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
944		len = len * 10 + *p - '0';
945	if (*p || len < last - first + 1)
946		return (-1);
947	if (first == -1) {
948		DEBUGF("content range: [*/%lld]\n", (long long)len);
949		*length = 0;
950	} else {
951		DEBUGF("content range: [%lld-%lld/%lld]\n",
952		    (long long)first, (long long)last, (long long)len);
953		*length = last - first + 1;
954	}
955	*offset = first;
956	*size = len;
957	return (0);
958}
959
960
961/*****************************************************************************
962 * Helper functions for authorization
963 */
964
965/*
966 * Base64 encoding
967 */
968static char *
969http_base64(const char *src)
970{
971	static const char base64[] =
972	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
973	    "abcdefghijklmnopqrstuvwxyz"
974	    "0123456789+/";
975	char *str, *dst;
976	size_t l;
977	int t;
978
979	l = strlen(src);
980	if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
981		return (NULL);
982	dst = str;
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;
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		break;
1003	case 1:
1004		t = src[0] << 16;
1005		dst[0] = base64[(t >> 18) & 0x3f];
1006		dst[1] = base64[(t >> 12) & 0x3f];
1007		dst[2] = dst[3] = '=';
1008		dst += 4;
1009		break;
1010	case 0:
1011		break;
1012	}
1013
1014	*dst = 0;
1015	return (str);
1016}
1017
1018
1019/*
1020 * Extract authorization parameters from environment value.
1021 * The value is like scheme:realm:user:pass
1022 */
1023typedef struct {
1024	char	*scheme;
1025	char	*realm;
1026	char	*user;
1027	char	*password;
1028} http_auth_params_t;
1029
1030static void
1031init_http_auth_params(http_auth_params_t *s)
1032{
1033	s->scheme = s->realm = s->user = s->password = NULL;
1034}
1035
1036static void
1037clean_http_auth_params(http_auth_params_t *s)
1038{
1039	if (s->scheme)
1040		free(s->scheme);
1041	if (s->realm)
1042		free(s->realm);
1043	if (s->user)
1044		free(s->user);
1045	if (s->password)
1046		free(s->password);
1047	init_http_auth_params(s);
1048}
1049
1050static int
1051http_authfromenv(const char *p, http_auth_params_t *parms)
1052{
1053	int ret = -1;
1054	char *v, *ve;
1055	char *str = strdup(p);
1056
1057	if (str == NULL) {
1058		fetch_syserr();
1059		return (-1);
1060	}
1061	v = str;
1062
1063	if ((ve = strchr(v, ':')) == NULL)
1064		goto out;
1065
1066	*ve = 0;
1067	if ((parms->scheme = strdup(v)) == NULL) {
1068		fetch_syserr();
1069		goto out;
1070	}
1071	v = ve + 1;
1072
1073	if ((ve = strchr(v, ':')) == NULL)
1074		goto out;
1075
1076	*ve = 0;
1077	if ((parms->realm = strdup(v)) == NULL) {
1078		fetch_syserr();
1079		goto out;
1080	}
1081	v = ve + 1;
1082
1083	if ((ve = strchr(v, ':')) == NULL)
1084		goto out;
1085
1086	*ve = 0;
1087	if ((parms->user = strdup(v)) == NULL) {
1088		fetch_syserr();
1089		goto out;
1090	}
1091	v = ve + 1;
1092
1093
1094	if ((parms->password = strdup(v)) == NULL) {
1095		fetch_syserr();
1096		goto out;
1097	}
1098	ret = 0;
1099out:
1100	if (ret == -1)
1101		clean_http_auth_params(parms);
1102	if (str)
1103		free(str);
1104	return (ret);
1105}
1106
1107
1108/*
1109 * Digest response: the code to compute the digest is taken from the
1110 * sample implementation in RFC2616
1111 */
1112#define IN const
1113#define OUT
1114
1115#define HASHLEN 16
1116typedef char HASH[HASHLEN];
1117#define HASHHEXLEN 32
1118typedef char HASHHEX[HASHHEXLEN+1];
1119
1120static const char *hexchars = "0123456789abcdef";
1121static void
1122CvtHex(IN HASH Bin, OUT HASHHEX Hex)
1123{
1124	unsigned short i;
1125	unsigned char j;
1126
1127	for (i = 0; i < HASHLEN; i++) {
1128		j = (Bin[i] >> 4) & 0xf;
1129		Hex[i*2] = hexchars[j];
1130		j = Bin[i] & 0xf;
1131		Hex[i*2+1] = hexchars[j];
1132	}
1133	Hex[HASHHEXLEN] = '\0';
1134};
1135
1136/* calculate H(A1) as per spec */
1137static void
1138DigestCalcHA1(
1139	IN char * pszAlg,
1140	IN char * pszUserName,
1141	IN char * pszRealm,
1142	IN char * pszPassword,
1143	IN char * pszNonce,
1144	IN char * pszCNonce,
1145	OUT HASHHEX SessionKey
1146	)
1147{
1148	MD5_CTX Md5Ctx;
1149	HASH HA1;
1150
1151	MD5Init(&Md5Ctx);
1152	MD5Update(&Md5Ctx, pszUserName, strlen(pszUserName));
1153	MD5Update(&Md5Ctx, ":", 1);
1154	MD5Update(&Md5Ctx, pszRealm, strlen(pszRealm));
1155	MD5Update(&Md5Ctx, ":", 1);
1156	MD5Update(&Md5Ctx, pszPassword, strlen(pszPassword));
1157	MD5Final(HA1, &Md5Ctx);
1158	if (strcasecmp(pszAlg, "md5-sess") == 0) {
1159
1160		MD5Init(&Md5Ctx);
1161		MD5Update(&Md5Ctx, HA1, HASHLEN);
1162		MD5Update(&Md5Ctx, ":", 1);
1163		MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1164		MD5Update(&Md5Ctx, ":", 1);
1165		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1166		MD5Final(HA1, &Md5Ctx);
1167	}
1168	CvtHex(HA1, SessionKey);
1169}
1170
1171/* calculate request-digest/response-digest as per HTTP Digest spec */
1172static void
1173DigestCalcResponse(
1174	IN HASHHEX HA1,           /* H(A1) */
1175	IN char * pszNonce,       /* nonce from server */
1176	IN char * pszNonceCount,  /* 8 hex digits */
1177	IN char * pszCNonce,      /* client nonce */
1178	IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
1179	IN char * pszMethod,      /* method from the request */
1180	IN char * pszDigestUri,   /* requested URL */
1181	IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
1182	OUT HASHHEX Response      /* request-digest or response-digest */
1183	)
1184{
1185#if 0
1186	DEBUGF("Calc: HA1[%s] Nonce[%s] qop[%s] method[%s] URI[%s]\n",
1187	    HA1, pszNonce, pszQop, pszMethod, pszDigestUri);
1188#endif
1189	MD5_CTX Md5Ctx;
1190	HASH HA2;
1191	HASH RespHash;
1192	HASHHEX HA2Hex;
1193
1194	// calculate H(A2)
1195	MD5Init(&Md5Ctx);
1196	MD5Update(&Md5Ctx, pszMethod, strlen(pszMethod));
1197	MD5Update(&Md5Ctx, ":", 1);
1198	MD5Update(&Md5Ctx, pszDigestUri, strlen(pszDigestUri));
1199	if (strcasecmp(pszQop, "auth-int") == 0) {
1200		MD5Update(&Md5Ctx, ":", 1);
1201		MD5Update(&Md5Ctx, HEntity, HASHHEXLEN);
1202	}
1203	MD5Final(HA2, &Md5Ctx);
1204	CvtHex(HA2, HA2Hex);
1205
1206	// calculate response
1207	MD5Init(&Md5Ctx);
1208	MD5Update(&Md5Ctx, HA1, HASHHEXLEN);
1209	MD5Update(&Md5Ctx, ":", 1);
1210	MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1211	MD5Update(&Md5Ctx, ":", 1);
1212	if (*pszQop) {
1213		MD5Update(&Md5Ctx, pszNonceCount, strlen(pszNonceCount));
1214		MD5Update(&Md5Ctx, ":", 1);
1215		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1216		MD5Update(&Md5Ctx, ":", 1);
1217		MD5Update(&Md5Ctx, pszQop, strlen(pszQop));
1218		MD5Update(&Md5Ctx, ":", 1);
1219	}
1220	MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
1221	MD5Final(RespHash, &Md5Ctx);
1222	CvtHex(RespHash, Response);
1223}
1224
1225/*
1226 * Generate/Send a Digest authorization header
1227 * This looks like: [Proxy-]Authorization: credentials
1228 *
1229 *  credentials      = "Digest" digest-response
1230 *  digest-response  = 1#( username | realm | nonce | digest-uri
1231 *                      | response | [ algorithm ] | [cnonce] |
1232 *                      [opaque] | [message-qop] |
1233 *                          [nonce-count]  | [auth-param] )
1234 *  username         = "username" "=" username-value
1235 *  username-value   = quoted-string
1236 *  digest-uri       = "uri" "=" digest-uri-value
1237 *  digest-uri-value = request-uri   ; As specified by HTTP/1.1
1238 *  message-qop      = "qop" "=" qop-value
1239 *  cnonce           = "cnonce" "=" cnonce-value
1240 *  cnonce-value     = nonce-value
1241 *  nonce-count      = "nc" "=" nc-value
1242 *  nc-value         = 8LHEX
1243 *  response         = "response" "=" request-digest
1244 *  request-digest = <"> 32LHEX <">
1245 */
1246static int
1247http_digest_auth(conn_t *conn, const char *hdr, http_auth_challenge_t *c,
1248		 http_auth_params_t *parms, struct url *url)
1249{
1250	int r;
1251	char noncecount[10];
1252	char cnonce[40];
1253	char *options = NULL;
1254
1255	if (!c->realm || !c->nonce) {
1256		DEBUGF("realm/nonce not set in challenge\n");
1257		return(-1);
1258	}
1259	if (!c->algo)
1260		c->algo = strdup("");
1261
1262	if (asprintf(&options, "%s%s%s%s",
1263	    *c->algo? ",algorithm=" : "", c->algo,
1264	    c->opaque? ",opaque=" : "", c->opaque?c->opaque:"") < 0)
1265		return (-1);
1266
1267	if (!c->qop) {
1268		c->qop = strdup("");
1269		*noncecount = 0;
1270		*cnonce = 0;
1271	} else {
1272		c->nc++;
1273		sprintf(noncecount, "%08x", c->nc);
1274		/* We don't try very hard with the cnonce ... */
1275		sprintf(cnonce, "%x%lx", getpid(), (unsigned long)time(0));
1276	}
1277
1278	HASHHEX HA1;
1279	DigestCalcHA1(c->algo, parms->user, c->realm,
1280		      parms->password, c->nonce, cnonce, HA1);
1281	DEBUGF("HA1: [%s]\n", HA1);
1282	HASHHEX digest, null;
1283	memset(null, 0, sizeof(null));
1284	DigestCalcResponse(HA1, c->nonce, noncecount, cnonce, c->qop,
1285			   "GET", url->doc, null, digest);
1286
1287	if (c->qop[0]) {
1288		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1289			     "nonce=\"%s\",uri=\"%s\",response=\"%s\","
1290			     "qop=\"auth\", cnonce=\"%s\", nc=%s%s",
1291			     hdr, parms->user, c->realm,
1292			     c->nonce, url->doc, digest,
1293			     cnonce, noncecount, options);
1294	} else {
1295		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1296			     "nonce=\"%s\",uri=\"%s\",response=\"%s\"%s",
1297			     hdr, parms->user, c->realm,
1298			     c->nonce, url->doc, digest, options);
1299	}
1300	if (options)
1301		free(options);
1302	return (r);
1303}
1304
1305/*
1306 * Encode username and password
1307 */
1308static int
1309http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
1310{
1311	char *upw, *auth;
1312	int r;
1313
1314	DEBUGF("basic: usr: [%s]\n", usr);
1315	DEBUGF("basic: pwd: [%s]\n", pwd);
1316	if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
1317		return (-1);
1318	auth = http_base64(upw);
1319	free(upw);
1320	if (auth == NULL)
1321		return (-1);
1322	r = http_cmd(conn, "%s: Basic %s", hdr, auth);
1323	free(auth);
1324	return (r);
1325}
1326
1327/*
1328 * Chose the challenge to answer and call the appropriate routine to
1329 * produce the header.
1330 */
1331static int
1332http_authorize(conn_t *conn, const char *hdr, http_auth_challenges_t *cs,
1333	       http_auth_params_t *parms, struct url *url)
1334{
1335	http_auth_challenge_t *digest = NULL;
1336	int i;
1337
1338	/* If user or pass are null we're not happy */
1339	if (!parms->user || !parms->password) {
1340		DEBUGF("NULL usr or pass\n");
1341		return (-1);
1342	}
1343
1344	/* Look for a Digest */
1345	for (i = 0; i < cs->count; i++) {
1346		if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1347			digest = cs->challenges[i];
1348	}
1349
1350	/* Error if "Digest" was specified and there is no Digest challenge */
1351	if (!digest &&
1352	    (parms->scheme && strcasecmp(parms->scheme, "digest") == 0)) {
1353		DEBUGF("Digest auth in env, not supported by peer\n");
1354		return (-1);
1355	}
1356	/*
1357	 * If "basic" was specified in the environment, or there is no Digest
1358	 * challenge, do the basic thing. Don't need a challenge for this,
1359	 * so no need to check basic!=NULL
1360	 */
1361	if (!digest ||
1362	    (parms->scheme && strcasecmp(parms->scheme, "basic") == 0))
1363		return (http_basic_auth(conn,hdr,parms->user,parms->password));
1364
1365	/* Else, prefer digest. We just checked that it's not NULL */
1366	return (http_digest_auth(conn, hdr, digest, parms, url));
1367}
1368
1369/*****************************************************************************
1370 * Helper functions for connecting to a server or proxy
1371 */
1372
1373/*
1374 * Connect to the correct HTTP server or proxy.
1375 */
1376static conn_t *
1377http_connect(struct url *URL, struct url *purl, const char *flags)
1378{
1379	struct url *curl;
1380	conn_t *conn;
1381	hdr_t h;
1382	http_headerbuf_t headerbuf;
1383	const char *p;
1384	int verbose;
1385	int af, val;
1386	int serrno;
1387	bool isproxyauth = false;
1388	http_auth_challenges_t proxy_challenges;
1389
1390#ifdef INET6
1391	af = AF_UNSPEC;
1392#else
1393	af = AF_INET;
1394#endif
1395
1396	verbose = CHECK_FLAG('v');
1397	if (CHECK_FLAG('4'))
1398		af = AF_INET;
1399#ifdef INET6
1400	else if (CHECK_FLAG('6'))
1401		af = AF_INET6;
1402#endif
1403
1404	curl = (purl != NULL) ? purl : URL;
1405
1406retry:
1407	if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1408		/* fetch_connect() has already set an error code */
1409		return (NULL);
1410	init_http_headerbuf(&headerbuf);
1411	if (strcmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1412		init_http_auth_challenges(&proxy_challenges);
1413		http_cmd(conn, "CONNECT %s:%d HTTP/1.1", URL->host, URL->port);
1414		http_cmd(conn, "Host: %s:%d", URL->host, URL->port);
1415		if (isproxyauth) {
1416			http_auth_params_t aparams;
1417			init_http_auth_params(&aparams);
1418			if (*purl->user || *purl->pwd) {
1419				aparams.user = strdup(purl->user);
1420				aparams.password = strdup(purl->pwd);
1421			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1422				    *p != '\0') {
1423				if (http_authfromenv(p, &aparams) < 0) {
1424					http_seterr(HTTP_NEED_PROXY_AUTH);
1425					fetch_syserr();
1426					goto ouch;
1427				}
1428			} else if (fetch_netrc_auth(purl) == 0) {
1429				aparams.user = strdup(purl->user);
1430				aparams.password = strdup(purl->pwd);
1431			} else {
1432				/*
1433				 * No auth information found in system - exiting
1434				 * with warning.
1435				 */
1436				warnx("Missing username and/or password set");
1437				fetch_syserr();
1438				goto ouch;
1439			}
1440			http_authorize(conn, "Proxy-Authorization",
1441			    &proxy_challenges, &aparams, purl);
1442			clean_http_auth_params(&aparams);
1443		}
1444		http_cmd(conn, "");
1445		/* Get reply from CONNECT Tunnel attempt */
1446		int httpreply = http_get_reply(conn);
1447		if (httpreply != HTTP_OK) {
1448			http_seterr(httpreply);
1449			/* If the error is a 407/HTTP_NEED_PROXY_AUTH */
1450			if (httpreply == HTTP_NEED_PROXY_AUTH &&
1451			    ! isproxyauth) {
1452				/* Try again with authentication. */
1453				clean_http_headerbuf(&headerbuf);
1454				fetch_close(conn);
1455				isproxyauth = true;
1456				goto retry;
1457			}
1458			goto ouch;
1459		}
1460		/* Read and discard the rest of the proxy response */
1461		if (fetch_getln(conn) < 0) {
1462			fetch_syserr();
1463			goto ouch;
1464		}
1465		do {
1466			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1467			case hdr_syserror:
1468				fetch_syserr();
1469				goto ouch;
1470			case hdr_error:
1471				http_seterr(HTTP_PROTOCOL_ERROR);
1472				goto ouch;
1473			default:
1474				/* ignore */ ;
1475			}
1476		} while (h > hdr_end);
1477	}
1478	if (strcmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1479	    fetch_ssl(conn, URL, verbose) == -1) {
1480		/* grrr */
1481		errno = EAUTH;
1482		fetch_syserr();
1483		goto ouch;
1484	}
1485
1486	val = 1;
1487	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1488
1489	clean_http_headerbuf(&headerbuf);
1490	return (conn);
1491ouch:
1492	serrno = errno;
1493	clean_http_headerbuf(&headerbuf);
1494	fetch_close(conn);
1495	errno = serrno;
1496	return (NULL);
1497}
1498
1499static struct url *
1500http_get_proxy(struct url * url, const char *flags)
1501{
1502	struct url *purl;
1503	char *p;
1504
1505	if (flags != NULL && strchr(flags, 'd') != NULL)
1506		return (NULL);
1507	if (fetch_no_proxy_match(url->host))
1508		return (NULL);
1509	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1510	    *p && (purl = fetchParseURL(p))) {
1511		if (!*purl->scheme)
1512			strcpy(purl->scheme, SCHEME_HTTP);
1513		if (!purl->port)
1514			purl->port = fetch_default_proxy_port(purl->scheme);
1515		if (strcmp(purl->scheme, SCHEME_HTTP) == 0)
1516			return (purl);
1517		fetchFreeURL(purl);
1518	}
1519	return (NULL);
1520}
1521
1522static void
1523http_print_html(FILE *out, FILE *in)
1524{
1525	ssize_t len = 0;
1526	size_t cap;
1527	char *line = NULL, *p, *q;
1528	int comment, tag;
1529
1530	comment = tag = 0;
1531	while ((len = getline(&line, &cap, in)) >= 0) {
1532		while (len && isspace((unsigned char)line[len - 1]))
1533			--len;
1534		for (p = q = line; q < line + len; ++q) {
1535			if (comment && *q == '-') {
1536				if (q + 2 < line + len &&
1537				    strcmp(q, "-->") == 0) {
1538					tag = comment = 0;
1539					q += 2;
1540				}
1541			} else if (tag && !comment && *q == '>') {
1542				p = q + 1;
1543				tag = 0;
1544			} else if (!tag && *q == '<') {
1545				if (q > p)
1546					fwrite(p, q - p, 1, out);
1547				tag = 1;
1548				if (q + 3 < line + len &&
1549				    strcmp(q, "<!--") == 0) {
1550					comment = 1;
1551					q += 3;
1552				}
1553			}
1554		}
1555		if (!tag && q > p)
1556			fwrite(p, q - p, 1, out);
1557		fputc('\n', out);
1558	}
1559
1560	free(line);
1561}
1562
1563
1564/*****************************************************************************
1565 * Core
1566 */
1567
1568FILE *
1569http_request(struct url *URL, const char *op, struct url_stat *us,
1570	struct url *purl, const char *flags)
1571{
1572
1573	return (http_request_body(URL, op, us, purl, flags, NULL, NULL));
1574}
1575
1576/*
1577 * Send a request and process the reply
1578 *
1579 * XXX This function is way too long, the do..while loop should be split
1580 * XXX off into a separate function.
1581 */
1582FILE *
1583http_request_body(struct url *URL, const char *op, struct url_stat *us,
1584	struct url *purl, const char *flags, const char *content_type,
1585	const char *body)
1586{
1587	char timebuf[80];
1588	char hbuf[MAXHOSTNAMELEN + 7], *host;
1589	conn_t *conn;
1590	struct url *url, *new;
1591	int chunked, direct, ims, noredirect, verbose;
1592	int e, i, n, val;
1593	off_t offset, clength, length, size;
1594	time_t mtime;
1595	const char *p;
1596	FILE *f;
1597	hdr_t h;
1598	struct tm *timestruct;
1599	http_headerbuf_t headerbuf;
1600	http_auth_challenges_t server_challenges;
1601	http_auth_challenges_t proxy_challenges;
1602	size_t body_len;
1603
1604	/* The following calls don't allocate anything */
1605	init_http_headerbuf(&headerbuf);
1606	init_http_auth_challenges(&server_challenges);
1607	init_http_auth_challenges(&proxy_challenges);
1608
1609	direct = CHECK_FLAG('d');
1610	noredirect = CHECK_FLAG('A');
1611	verbose = CHECK_FLAG('v');
1612	ims = CHECK_FLAG('i');
1613
1614	if (direct && purl) {
1615		fetchFreeURL(purl);
1616		purl = NULL;
1617	}
1618
1619	/* try the provided URL first */
1620	url = URL;
1621
1622	n = MAX_REDIRECT;
1623	i = 0;
1624
1625	e = HTTP_PROTOCOL_ERROR;
1626	do {
1627		new = NULL;
1628		chunked = 0;
1629		offset = 0;
1630		clength = -1;
1631		length = -1;
1632		size = -1;
1633		mtime = 0;
1634
1635		/* check port */
1636		if (!url->port)
1637			url->port = fetch_default_port(url->scheme);
1638
1639		/* were we redirected to an FTP URL? */
1640		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1641			if (strcmp(op, "GET") == 0)
1642				return (ftp_request(url, "RETR", us, purl, flags));
1643			else if (strcmp(op, "HEAD") == 0)
1644				return (ftp_request(url, "STAT", us, purl, flags));
1645		}
1646
1647		/* connect to server or proxy */
1648		if ((conn = http_connect(url, purl, flags)) == NULL)
1649			goto ouch;
1650
1651		/* append port number only if necessary */
1652		host = url->host;
1653		if (url->port != fetch_default_port(url->scheme)) {
1654			snprintf(hbuf, sizeof(hbuf), "%s:%d", host, url->port);
1655			host = hbuf;
1656		}
1657
1658		/* send request */
1659		if (verbose)
1660			fetch_info("requesting %s://%s%s",
1661			    url->scheme, host, url->doc);
1662		if (purl && strcmp(url->scheme, SCHEME_HTTPS) != 0) {
1663			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1664			    op, url->scheme, host, url->doc);
1665		} else {
1666			http_cmd(conn, "%s %s HTTP/1.1",
1667			    op, url->doc);
1668		}
1669
1670		if (ims && url->ims_time) {
1671			timestruct = gmtime((time_t *)&url->ims_time);
1672			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1673			    timestruct);
1674			if (verbose)
1675				fetch_info("If-Modified-Since: %s", timebuf);
1676			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1677		}
1678		/* virtual host */
1679		http_cmd(conn, "Host: %s", host);
1680
1681		/*
1682		 * Proxy authorization: we only send auth after we received
1683		 * a 407 error. We do not first try basic anyway (changed
1684		 * when support was added for digest-auth)
1685		 */
1686		if (purl && proxy_challenges.valid) {
1687			http_auth_params_t aparams;
1688			init_http_auth_params(&aparams);
1689			if (*purl->user || *purl->pwd) {
1690				aparams.user = strdup(purl->user);
1691				aparams.password = strdup(purl->pwd);
1692			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1693				   *p != '\0') {
1694				if (http_authfromenv(p, &aparams) < 0) {
1695					http_seterr(HTTP_NEED_PROXY_AUTH);
1696					goto ouch;
1697				}
1698			} else if (fetch_netrc_auth(purl) == 0) {
1699				aparams.user = strdup(purl->user);
1700				aparams.password = strdup(purl->pwd);
1701			}
1702			http_authorize(conn, "Proxy-Authorization",
1703				       &proxy_challenges, &aparams, url);
1704			clean_http_auth_params(&aparams);
1705		}
1706
1707		/*
1708		 * Server authorization: we never send "a priori"
1709		 * Basic auth, which used to be done if user/pass were
1710		 * set in the url. This would be weird because we'd send the
1711		 * password in the clear even if Digest is finally to be
1712		 * used (it would have made more sense for the
1713		 * pre-digest version to do this when Basic was specified
1714		 * in the environment)
1715		 */
1716		if (server_challenges.valid) {
1717			http_auth_params_t aparams;
1718			init_http_auth_params(&aparams);
1719			if (*url->user || *url->pwd) {
1720				aparams.user = strdup(url->user);
1721				aparams.password = strdup(url->pwd);
1722			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1723				   *p != '\0') {
1724				if (http_authfromenv(p, &aparams) < 0) {
1725					http_seterr(HTTP_NEED_AUTH);
1726					goto ouch;
1727				}
1728			} else if (fetch_netrc_auth(url) == 0) {
1729				aparams.user = strdup(url->user);
1730				aparams.password = strdup(url->pwd);
1731			} else if (fetchAuthMethod &&
1732				   fetchAuthMethod(url) == 0) {
1733				aparams.user = strdup(url->user);
1734				aparams.password = strdup(url->pwd);
1735			} else {
1736				http_seterr(HTTP_NEED_AUTH);
1737				goto ouch;
1738			}
1739			http_authorize(conn, "Authorization",
1740				       &server_challenges, &aparams, url);
1741			clean_http_auth_params(&aparams);
1742		}
1743
1744		/* other headers */
1745		if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1746			if (*p != '\0')
1747				http_cmd(conn, "Accept: %s", p);
1748		} else {
1749			http_cmd(conn, "Accept: */*");
1750		}
1751		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1752			if (strcasecmp(p, "auto") == 0)
1753				http_cmd(conn, "Referer: %s://%s%s",
1754				    url->scheme, host, url->doc);
1755			else
1756				http_cmd(conn, "Referer: %s", p);
1757		}
1758		if ((p = getenv("HTTP_USER_AGENT")) != NULL) {
1759			/* no User-Agent if defined but empty */
1760			if  (*p != '\0')
1761				http_cmd(conn, "User-Agent: %s", p);
1762		} else {
1763			/* default User-Agent */
1764			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER,
1765			    getprogname());
1766		}
1767		if (url->offset > 0)
1768			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1769		http_cmd(conn, "Connection: close");
1770
1771		if (body) {
1772			body_len = strlen(body);
1773			http_cmd(conn, "Content-Length: %zu", body_len);
1774			if (content_type != NULL)
1775				http_cmd(conn, "Content-Type: %s", content_type);
1776		}
1777
1778		http_cmd(conn, "");
1779
1780		if (body)
1781			fetch_write(conn, body, body_len);
1782
1783		/*
1784		 * Force the queued request to be dispatched.  Normally, one
1785		 * would do this with shutdown(2) but squid proxies can be
1786		 * configured to disallow such half-closed connections.  To
1787		 * be compatible with such configurations, fiddle with socket
1788		 * options to force the pending data to be written.
1789		 */
1790		val = 0;
1791		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1792			   sizeof(val));
1793		val = 1;
1794		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1795			   sizeof(val));
1796
1797		/* get reply */
1798		switch (http_get_reply(conn)) {
1799		case HTTP_OK:
1800		case HTTP_PARTIAL:
1801		case HTTP_NOT_MODIFIED:
1802			/* fine */
1803			break;
1804		case HTTP_MOVED_PERM:
1805		case HTTP_MOVED_TEMP:
1806		case HTTP_TEMP_REDIRECT:
1807		case HTTP_PERM_REDIRECT:
1808		case HTTP_SEE_OTHER:
1809		case HTTP_USE_PROXY:
1810			/*
1811			 * Not so fine, but we still have to read the
1812			 * headers to get the new location.
1813			 */
1814			break;
1815		case HTTP_NEED_AUTH:
1816			if (server_challenges.valid) {
1817				/*
1818				 * We already sent out authorization code,
1819				 * so there's nothing more we can do.
1820				 */
1821				http_seterr(conn->err);
1822				goto ouch;
1823			}
1824			/* try again, but send the password this time */
1825			if (verbose)
1826				fetch_info("server requires authorization");
1827			break;
1828		case HTTP_NEED_PROXY_AUTH:
1829			if (proxy_challenges.valid) {
1830				/*
1831				 * We already sent our proxy
1832				 * authorization code, so there's
1833				 * nothing more we can do. */
1834				http_seterr(conn->err);
1835				goto ouch;
1836			}
1837			/* try again, but send the password this time */
1838			if (verbose)
1839				fetch_info("proxy requires authorization");
1840			break;
1841		case HTTP_BAD_RANGE:
1842			/*
1843			 * This can happen if we ask for 0 bytes because
1844			 * we already have the whole file.  Consider this
1845			 * a success for now, and check sizes later.
1846			 */
1847			break;
1848		case HTTP_PROTOCOL_ERROR:
1849			/* fall through */
1850		case -1:
1851			fetch_syserr();
1852			goto ouch;
1853		default:
1854			http_seterr(conn->err);
1855			if (!verbose)
1856				goto ouch;
1857			/* fall through so we can get the full error message */
1858		}
1859
1860		/* get headers. http_next_header expects one line readahead */
1861		if (fetch_getln(conn) == -1) {
1862			fetch_syserr();
1863			goto ouch;
1864		}
1865		do {
1866			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1867			case hdr_syserror:
1868				fetch_syserr();
1869				goto ouch;
1870			case hdr_error:
1871				http_seterr(HTTP_PROTOCOL_ERROR);
1872				goto ouch;
1873			case hdr_content_length:
1874				http_parse_length(p, &clength);
1875				break;
1876			case hdr_content_range:
1877				http_parse_range(p, &offset, &length, &size);
1878				break;
1879			case hdr_last_modified:
1880				http_parse_mtime(p, &mtime);
1881				break;
1882			case hdr_location:
1883				if (!HTTP_REDIRECT(conn->err))
1884					break;
1885				/*
1886				 * if the A flag is set, we don't follow
1887				 * temporary redirects.
1888				 */
1889				if (noredirect &&
1890				    conn->err != HTTP_MOVED_PERM &&
1891				    conn->err != HTTP_PERM_REDIRECT &&
1892				    conn->err != HTTP_USE_PROXY) {
1893					n = 1;
1894					break;
1895				}
1896				if (new)
1897					free(new);
1898				if (verbose)
1899					fetch_info("%d redirect to %s",
1900					    conn->err, p);
1901				if (*p == '/')
1902					/* absolute path */
1903					new = fetchMakeURL(url->scheme, url->host,
1904					    url->port, p, url->user, url->pwd);
1905				else
1906					new = fetchParseURL(p);
1907				if (new == NULL) {
1908					/* XXX should set an error code */
1909					DEBUGF("failed to parse new URL\n");
1910					goto ouch;
1911				}
1912
1913				/* Only copy credentials if the host matches */
1914				if (strcmp(new->host, url->host) == 0 &&
1915				    !*new->user && !*new->pwd) {
1916					strcpy(new->user, url->user);
1917					strcpy(new->pwd, url->pwd);
1918				}
1919				new->offset = url->offset;
1920				new->length = url->length;
1921				new->ims_time = url->ims_time;
1922				break;
1923			case hdr_transfer_encoding:
1924				/* XXX weak test*/
1925				chunked = (strcasecmp(p, "chunked") == 0);
1926				break;
1927			case hdr_www_authenticate:
1928				if (conn->err != HTTP_NEED_AUTH)
1929					break;
1930				if (http_parse_authenticate(p, &server_challenges) == 0)
1931					++n;
1932				break;
1933			case hdr_proxy_authenticate:
1934				if (conn->err != HTTP_NEED_PROXY_AUTH)
1935					break;
1936				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1937					++n;
1938				break;
1939			case hdr_end:
1940				/* fall through */
1941			case hdr_unknown:
1942				/* ignore */
1943				break;
1944			}
1945		} while (h > hdr_end);
1946
1947		/* we need to provide authentication */
1948		if (conn->err == HTTP_NEED_AUTH ||
1949		    conn->err == HTTP_NEED_PROXY_AUTH) {
1950			e = conn->err;
1951			if ((conn->err == HTTP_NEED_AUTH &&
1952			     !server_challenges.valid) ||
1953			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1954			     !proxy_challenges.valid)) {
1955				/* 401/7 but no www/proxy-authenticate ?? */
1956				DEBUGF("%03d without auth header\n", conn->err);
1957				goto ouch;
1958			}
1959			fetch_close(conn);
1960			conn = NULL;
1961			continue;
1962		}
1963
1964		/* requested range not satisfiable */
1965		if (conn->err == HTTP_BAD_RANGE) {
1966			if (url->offset > 0 && url->length == 0) {
1967				/* asked for 0 bytes; fake it */
1968				offset = url->offset;
1969				clength = -1;
1970				conn->err = HTTP_OK;
1971				break;
1972			} else {
1973				http_seterr(conn->err);
1974				goto ouch;
1975			}
1976		}
1977
1978		/* we have a hit or an error */
1979		if (conn->err == HTTP_OK
1980		    || conn->err == HTTP_NOT_MODIFIED
1981		    || conn->err == HTTP_PARTIAL
1982		    || HTTP_ERROR(conn->err))
1983			break;
1984
1985		/* all other cases: we got a redirect */
1986		e = conn->err;
1987		clean_http_auth_challenges(&server_challenges);
1988		fetch_close(conn);
1989		conn = NULL;
1990		if (!new) {
1991			DEBUGF("redirect with no new location\n");
1992			break;
1993		}
1994		if (url != URL)
1995			fetchFreeURL(url);
1996		url = new;
1997	} while (++i < n);
1998
1999	/* we failed, or ran out of retries */
2000	if (conn == NULL) {
2001		http_seterr(e);
2002		goto ouch;
2003	}
2004
2005	DEBUGF("offset %lld, length %lld, size %lld, clength %lld\n",
2006	    (long long)offset, (long long)length,
2007	    (long long)size, (long long)clength);
2008
2009	if (conn->err == HTTP_NOT_MODIFIED) {
2010		http_seterr(HTTP_NOT_MODIFIED);
2011		return (NULL);
2012	}
2013
2014	/* check for inconsistencies */
2015	if (clength != -1 && length != -1 && clength != length) {
2016		http_seterr(HTTP_PROTOCOL_ERROR);
2017		goto ouch;
2018	}
2019	if (clength == -1)
2020		clength = length;
2021	if (clength != -1)
2022		length = offset + clength;
2023	if (length != -1 && size != -1 && length != size) {
2024		http_seterr(HTTP_PROTOCOL_ERROR);
2025		goto ouch;
2026	}
2027	if (size == -1)
2028		size = length;
2029
2030	/* fill in stats */
2031	if (us) {
2032		us->size = size;
2033		us->atime = us->mtime = mtime;
2034	}
2035
2036	/* too far? */
2037	if (URL->offset > 0 && offset > URL->offset) {
2038		http_seterr(HTTP_PROTOCOL_ERROR);
2039		goto ouch;
2040	}
2041
2042	/* report back real offset and size */
2043	URL->offset = offset;
2044	URL->length = clength;
2045
2046	/* wrap it up in a FILE */
2047	if ((f = http_funopen(conn, chunked)) == NULL) {
2048		fetch_syserr();
2049		goto ouch;
2050	}
2051
2052	if (url != URL)
2053		fetchFreeURL(url);
2054	if (purl)
2055		fetchFreeURL(purl);
2056
2057	if (HTTP_ERROR(conn->err)) {
2058		http_print_html(stderr, f);
2059		fclose(f);
2060		f = NULL;
2061	}
2062	clean_http_headerbuf(&headerbuf);
2063	clean_http_auth_challenges(&server_challenges);
2064	clean_http_auth_challenges(&proxy_challenges);
2065	return (f);
2066
2067ouch:
2068	if (url != URL)
2069		fetchFreeURL(url);
2070	if (purl)
2071		fetchFreeURL(purl);
2072	if (conn != NULL)
2073		fetch_close(conn);
2074	clean_http_headerbuf(&headerbuf);
2075	clean_http_auth_challenges(&server_challenges);
2076	clean_http_auth_challenges(&proxy_challenges);
2077	return (NULL);
2078}
2079
2080
2081/*****************************************************************************
2082 * Entry points
2083 */
2084
2085/*
2086 * Retrieve and stat a file by HTTP
2087 */
2088FILE *
2089fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
2090{
2091	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
2092}
2093
2094/*
2095 * Retrieve a file by HTTP
2096 */
2097FILE *
2098fetchGetHTTP(struct url *URL, const char *flags)
2099{
2100	return (fetchXGetHTTP(URL, NULL, flags));
2101}
2102
2103/*
2104 * Store a file by HTTP
2105 */
2106FILE *
2107fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2108{
2109	warnx("fetchPutHTTP(): not implemented");
2110	return (NULL);
2111}
2112
2113/*
2114 * Get an HTTP document's metadata
2115 */
2116int
2117fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2118{
2119	FILE *f;
2120
2121	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2122	if (f == NULL)
2123		return (-1);
2124	fclose(f);
2125	return (0);
2126}
2127
2128/*
2129 * List a directory
2130 */
2131struct url_ent *
2132fetchListHTTP(struct url *url __unused, const char *flags __unused)
2133{
2134	warnx("fetchListHTTP(): not implemented");
2135	return (NULL);
2136}
2137
2138/*
2139 * Arbitrary HTTP verb and content requests
2140 */
2141FILE *
2142fetchReqHTTP(struct url *URL, const char *method, const char *flags,
2143	const char *content_type, const char *body)
2144{
2145
2146	return (http_request_body(URL, method, NULL, http_get_proxy(URL, flags),
2147	    flags, content_type, body));
2148}
2149