xref: /freebsd/lib/libfetch/http.c (revision d8b88105c2ccf7686552516877f541efb54fb6c8)
1 /*-
2  * Copyright (c) 2000-2013 Dag-Erling Smørgrav
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("$FreeBSD$");
31 
32 /*
33  * The following copyright applies to the base64 code:
34  *
35  *-
36  * Copyright 1997 Massachusetts Institute of Technology
37  *
38  * Permission to use, copy, modify, and distribute this software and
39  * its documentation for any purpose and without fee is hereby
40  * granted, provided that both the above copyright notice and this
41  * permission notice appear in all copies, that both the above
42  * copyright notice and this permission notice appear in all
43  * supporting documentation, and that the name of M.I.T. not be used
44  * in advertising or publicity pertaining to distribution of the
45  * software without specific, written prior permission.  M.I.T. makes
46  * no representations about the suitability of this software for any
47  * purpose.  It is provided "as is" without express or implied
48  * warranty.
49  *
50  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
51  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
52  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
53  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
54  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
55  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
56  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
57  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
58  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
59  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
60  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  */
63 
64 #include <sys/param.h>
65 #include <sys/socket.h>
66 #include <sys/time.h>
67 
68 #include <ctype.h>
69 #include <err.h>
70 #include <errno.h>
71 #include <locale.h>
72 #include <netdb.h>
73 #include <stdarg.h>
74 #include <stdio.h>
75 #include <stdlib.h>
76 #include <string.h>
77 #include <time.h>
78 #include <unistd.h>
79 
80 #ifdef WITH_SSL
81 #include <openssl/md5.h>
82 #define MD5Init(c) MD5_Init(c)
83 #define MD5Update(c, data, len) MD5_Update(c, data, len)
84 #define MD5Final(md, c) MD5_Final(md, c)
85 #else
86 #include <md5.h>
87 #endif
88 
89 #include <netinet/in.h>
90 #include <netinet/tcp.h>
91 
92 #include "fetch.h"
93 #include "common.h"
94 #include "httperr.h"
95 
96 /* Maximum number of redirects to follow */
97 #define MAX_REDIRECT 20
98 
99 /* Symbolic names for reply codes we care about */
100 #define HTTP_OK			200
101 #define HTTP_PARTIAL		206
102 #define HTTP_MOVED_PERM		301
103 #define HTTP_MOVED_TEMP		302
104 #define HTTP_SEE_OTHER		303
105 #define HTTP_NOT_MODIFIED	304
106 #define HTTP_USE_PROXY		305
107 #define HTTP_TEMP_REDIRECT	307
108 #define HTTP_PERM_REDIRECT	308
109 #define HTTP_NEED_AUTH		401
110 #define HTTP_NEED_PROXY_AUTH	407
111 #define HTTP_BAD_RANGE		416
112 #define HTTP_PROTOCOL_ERROR	999
113 
114 #define HTTP_REDIRECT(xyz) ((xyz) == HTTP_MOVED_PERM \
115 			    || (xyz) == HTTP_MOVED_TEMP \
116 			    || (xyz) == HTTP_TEMP_REDIRECT \
117 			    || (xyz) == HTTP_USE_PROXY \
118 			    || (xyz) == HTTP_SEE_OTHER)
119 
120 #define HTTP_ERROR(xyz) ((xyz) > 400 && (xyz) < 599)
121 
122 
123 /*****************************************************************************
124  * I/O functions for decoding chunked streams
125  */
126 
127 struct httpio
128 {
129 	conn_t		*conn;		/* connection */
130 	int		 chunked;	/* chunked mode */
131 	char		*buf;		/* chunk buffer */
132 	size_t		 bufsize;	/* size of chunk buffer */
133 	ssize_t		 buflen;	/* amount of data currently in buffer */
134 	int		 bufpos;	/* current read offset in buffer */
135 	int		 eof;		/* end-of-file flag */
136 	int		 error;		/* error flag */
137 	size_t		 chunksize;	/* remaining size of current chunk */
138 #ifndef NDEBUG
139 	size_t		 total;
140 #endif
141 };
142 
143 /*
144  * Get next chunk header
145  */
146 static int
147 http_new_chunk(struct httpio *io)
148 {
149 	char *p;
150 
151 	if (fetch_getln(io->conn) == -1)
152 		return (-1);
153 
154 	if (io->conn->buflen < 2 || !isxdigit((unsigned char)*io->conn->buf))
155 		return (-1);
156 
157 	for (p = io->conn->buf; *p && !isspace((unsigned char)*p); ++p) {
158 		if (*p == ';')
159 			break;
160 		if (!isxdigit((unsigned char)*p))
161 			return (-1);
162 		if (isdigit((unsigned char)*p)) {
163 			io->chunksize = io->chunksize * 16 +
164 			    *p - '0';
165 		} else {
166 			io->chunksize = io->chunksize * 16 +
167 			    10 + tolower((unsigned char)*p) - 'a';
168 		}
169 	}
170 
171 #ifndef NDEBUG
172 	if (fetchDebug) {
173 		io->total += io->chunksize;
174 		if (io->chunksize == 0)
175 			fprintf(stderr, "%s(): end of last chunk\n", __func__);
176 		else
177 			fprintf(stderr, "%s(): new chunk: %lu (%lu)\n",
178 			    __func__, (unsigned long)io->chunksize,
179 			    (unsigned long)io->total);
180 	}
181 #endif
182 
183 	return (io->chunksize);
184 }
185 
186 /*
187  * Grow the input buffer to at least len bytes
188  */
189 static inline int
190 http_growbuf(struct httpio *io, size_t len)
191 {
192 	char *tmp;
193 
194 	if (io->bufsize >= len)
195 		return (0);
196 
197 	if ((tmp = realloc(io->buf, len)) == NULL)
198 		return (-1);
199 	io->buf = tmp;
200 	io->bufsize = len;
201 	return (0);
202 }
203 
204 /*
205  * Fill the input buffer, do chunk decoding on the fly
206  */
207 static int
208 http_fillbuf(struct httpio *io, size_t len)
209 {
210 	ssize_t nbytes;
211 	char ch;
212 
213 	if (io->error)
214 		return (-1);
215 	if (io->eof)
216 		return (0);
217 
218 	if (io->chunked == 0) {
219 		if (http_growbuf(io, len) == -1)
220 			return (-1);
221 		if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
222 			io->error = errno;
223 			return (-1);
224 		}
225 		io->buflen = nbytes;
226 		io->bufpos = 0;
227 		return (io->buflen);
228 	}
229 
230 	if (io->chunksize == 0) {
231 		switch (http_new_chunk(io)) {
232 		case -1:
233 			io->error = 1;
234 			return (-1);
235 		case 0:
236 			io->eof = 1;
237 			return (0);
238 		}
239 	}
240 
241 	if (len > io->chunksize)
242 		len = io->chunksize;
243 	if (http_growbuf(io, len) == -1)
244 		return (-1);
245 	if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
246 		io->error = errno;
247 		return (-1);
248 	}
249 	io->buflen = nbytes;
250 	io->chunksize -= io->buflen;
251 
252 	if (io->chunksize == 0) {
253 		if (fetch_read(io->conn, &ch, 1) != 1 || ch != '\r' ||
254 		    fetch_read(io->conn, &ch, 1) != 1 || ch != '\n')
255 			return (-1);
256 	}
257 
258 	io->bufpos = 0;
259 
260 	return (io->buflen);
261 }
262 
263 /*
264  * Read function
265  */
266 static int
267 http_readfn(void *v, char *buf, int len)
268 {
269 	struct httpio *io = (struct httpio *)v;
270 	int rlen;
271 
272 	if (io->error)
273 		return (-1);
274 	if (io->eof)
275 		return (0);
276 
277 	/* empty buffer */
278 	if (!io->buf || io->bufpos == io->buflen) {
279 		if (http_fillbuf(io, len) < 1) {
280 			if (io->error == EINTR)
281 				io->error = 0;
282 			return (-1);
283 		}
284 	}
285 
286 	rlen = io->buflen - io->bufpos;
287 	if (len < rlen)
288 		rlen = len;
289 	memcpy(buf, io->buf + io->bufpos, rlen);
290 	io->bufpos += rlen;
291 	return (rlen);
292 }
293 
294 /*
295  * Write function
296  */
297 static int
298 http_writefn(void *v, const char *buf, int len)
299 {
300 	struct httpio *io = (struct httpio *)v;
301 
302 	return (fetch_write(io->conn, buf, len));
303 }
304 
305 /*
306  * Close function
307  */
308 static int
309 http_closefn(void *v)
310 {
311 	struct httpio *io = (struct httpio *)v;
312 	int r;
313 
314 	r = fetch_close(io->conn);
315 	if (io->buf)
316 		free(io->buf);
317 	free(io);
318 	return (r);
319 }
320 
321 /*
322  * Wrap a file descriptor up
323  */
324 static FILE *
325 http_funopen(conn_t *conn, int chunked)
326 {
327 	struct httpio *io;
328 	FILE *f;
329 
330 	if ((io = calloc(1, sizeof(*io))) == NULL) {
331 		fetch_syserr();
332 		return (NULL);
333 	}
334 	io->conn = conn;
335 	io->chunked = chunked;
336 	f = funopen(io, http_readfn, http_writefn, NULL, http_closefn);
337 	if (f == NULL) {
338 		fetch_syserr();
339 		free(io);
340 		return (NULL);
341 	}
342 	return (f);
343 }
344 
345 
346 /*****************************************************************************
347  * Helper functions for talking to the server and parsing its replies
348  */
349 
350 /* Header types */
351 typedef enum {
352 	hdr_syserror = -2,
353 	hdr_error = -1,
354 	hdr_end = 0,
355 	hdr_unknown = 1,
356 	hdr_content_length,
357 	hdr_content_range,
358 	hdr_last_modified,
359 	hdr_location,
360 	hdr_transfer_encoding,
361 	hdr_www_authenticate,
362 	hdr_proxy_authenticate,
363 } hdr_t;
364 
365 /* Names of interesting headers */
366 static struct {
367 	hdr_t		 num;
368 	const char	*name;
369 } hdr_names[] = {
370 	{ hdr_content_length,		"Content-Length" },
371 	{ hdr_content_range,		"Content-Range" },
372 	{ hdr_last_modified,		"Last-Modified" },
373 	{ hdr_location,			"Location" },
374 	{ hdr_transfer_encoding,	"Transfer-Encoding" },
375 	{ hdr_www_authenticate,		"WWW-Authenticate" },
376 	{ hdr_proxy_authenticate,	"Proxy-Authenticate" },
377 	{ hdr_unknown,			NULL },
378 };
379 
380 /*
381  * Send a formatted line; optionally echo to terminal
382  */
383 static int
384 http_cmd(conn_t *conn, const char *fmt, ...)
385 {
386 	va_list ap;
387 	size_t len;
388 	char *msg;
389 	int r;
390 
391 	va_start(ap, fmt);
392 	len = vasprintf(&msg, fmt, ap);
393 	va_end(ap);
394 
395 	if (msg == NULL) {
396 		errno = ENOMEM;
397 		fetch_syserr();
398 		return (-1);
399 	}
400 
401 	r = fetch_putln(conn, msg, len);
402 	free(msg);
403 
404 	if (r == -1) {
405 		fetch_syserr();
406 		return (-1);
407 	}
408 
409 	return (0);
410 }
411 
412 /*
413  * Get and parse status line
414  */
415 static int
416 http_get_reply(conn_t *conn)
417 {
418 	char *p;
419 
420 	if (fetch_getln(conn) == -1)
421 		return (-1);
422 	/*
423 	 * A valid status line looks like "HTTP/m.n xyz reason" where m
424 	 * and n are the major and minor protocol version numbers and xyz
425 	 * is the reply code.
426 	 * Unfortunately, there are servers out there (NCSA 1.5.1, to name
427 	 * just one) that do not send a version number, so we can't rely
428 	 * on finding one, but if we do, insist on it being 1.0 or 1.1.
429 	 * We don't care about the reason phrase.
430 	 */
431 	if (strncmp(conn->buf, "HTTP", 4) != 0)
432 		return (HTTP_PROTOCOL_ERROR);
433 	p = conn->buf + 4;
434 	if (*p == '/') {
435 		if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
436 			return (HTTP_PROTOCOL_ERROR);
437 		p += 4;
438 	}
439 	if (*p != ' ' ||
440 	    !isdigit((unsigned char)p[1]) ||
441 	    !isdigit((unsigned char)p[2]) ||
442 	    !isdigit((unsigned char)p[3]))
443 		return (HTTP_PROTOCOL_ERROR);
444 
445 	conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
446 	return (conn->err);
447 }
448 
449 /*
450  * Check a header; if the type matches the given string, return a pointer
451  * to the beginning of the value.
452  */
453 static const char *
454 http_match(const char *str, const char *hdr)
455 {
456 	while (*str && *hdr &&
457 	    tolower((unsigned char)*str++) == tolower((unsigned char)*hdr++))
458 		/* nothing */;
459 	if (*str || *hdr != ':')
460 		return (NULL);
461 	while (*hdr && isspace((unsigned char)*++hdr))
462 		/* nothing */;
463 	return (hdr);
464 }
465 
466 
467 /*
468  * Get the next header and return the appropriate symbolic code.  We
469  * need to read one line ahead for checking for a continuation line
470  * belonging to the current header (continuation lines start with
471  * white space).
472  *
473  * We get called with a fresh line already in the conn buffer, either
474  * from the previous http_next_header() invocation, or, the first
475  * time, from a fetch_getln() performed by our caller.
476  *
477  * This stops when we encounter an empty line (we dont read beyond the header
478  * area).
479  *
480  * Note that the "headerbuf" is just a place to return the result. Its
481  * contents are not used for the next call. This means that no cleanup
482  * is needed when ie doing another connection, just call the cleanup when
483  * fully done to deallocate memory.
484  */
485 
486 /* Limit the max number of continuation lines to some reasonable value */
487 #define HTTP_MAX_CONT_LINES 10
488 
489 /* Place into which to build a header from one or several lines */
490 typedef struct {
491 	char	*buf;		/* buffer */
492 	size_t	 bufsize;	/* buffer size */
493 	size_t	 buflen;	/* length of buffer contents */
494 } http_headerbuf_t;
495 
496 static void
497 init_http_headerbuf(http_headerbuf_t *buf)
498 {
499 	buf->buf = NULL;
500 	buf->bufsize = 0;
501 	buf->buflen = 0;
502 }
503 
504 static void
505 clean_http_headerbuf(http_headerbuf_t *buf)
506 {
507 	if (buf->buf)
508 		free(buf->buf);
509 	init_http_headerbuf(buf);
510 }
511 
512 /* Remove whitespace at the end of the buffer */
513 static void
514 http_conn_trimright(conn_t *conn)
515 {
516 	while (conn->buflen &&
517 	       isspace((unsigned char)conn->buf[conn->buflen - 1]))
518 		conn->buflen--;
519 	conn->buf[conn->buflen] = '\0';
520 }
521 
522 static hdr_t
523 http_next_header(conn_t *conn, http_headerbuf_t *hbuf, const char **p)
524 {
525 	unsigned int i, len;
526 
527 	/*
528 	 * Have to do the stripping here because of the first line. So
529 	 * it's done twice for the subsequent lines. No big deal
530 	 */
531 	http_conn_trimright(conn);
532 	if (conn->buflen == 0)
533 		return (hdr_end);
534 
535 	/* Copy the line to the headerbuf */
536 	if (hbuf->bufsize < conn->buflen + 1) {
537 		if ((hbuf->buf = realloc(hbuf->buf, conn->buflen + 1)) == NULL)
538 			return (hdr_syserror);
539 		hbuf->bufsize = conn->buflen + 1;
540 	}
541 	strcpy(hbuf->buf, conn->buf);
542 	hbuf->buflen = conn->buflen;
543 
544 	/*
545 	 * Fetch possible continuation lines. Stop at 1st non-continuation
546 	 * and leave it in the conn buffer
547 	 */
548 	for (i = 0; i < HTTP_MAX_CONT_LINES; i++) {
549 		if (fetch_getln(conn) == -1)
550 			return (hdr_syserror);
551 
552 		/*
553 		 * Note: we carry on the idea from the previous version
554 		 * that a pure whitespace line is equivalent to an empty
555 		 * one (so it's not continuation and will be handled when
556 		 * we are called next)
557 		 */
558 		http_conn_trimright(conn);
559 		if (conn->buf[0] != ' ' && conn->buf[0] != "\t"[0])
560 			break;
561 
562 		/* Got a continuation line. Concatenate to previous */
563 		len = hbuf->buflen + conn->buflen;
564 		if (hbuf->bufsize < len + 1) {
565 			len *= 2;
566 			if ((hbuf->buf = realloc(hbuf->buf, len + 1)) == NULL)
567 				return (hdr_syserror);
568 			hbuf->bufsize = len + 1;
569 		}
570 		strcpy(hbuf->buf + hbuf->buflen, conn->buf);
571 		hbuf->buflen += conn->buflen;
572 	}
573 
574 	/*
575 	 * We could check for malformed headers but we don't really care.
576 	 * A valid header starts with a token immediately followed by a
577 	 * colon; a token is any sequence of non-control, non-whitespace
578 	 * characters except "()<>@,;:\\\"{}".
579 	 */
580 	for (i = 0; hdr_names[i].num != hdr_unknown; i++)
581 		if ((*p = http_match(hdr_names[i].name, hbuf->buf)) != NULL)
582 			return (hdr_names[i].num);
583 
584 	return (hdr_unknown);
585 }
586 
587 /**************************
588  * [Proxy-]Authenticate header parsing
589  */
590 
591 /*
592  * Read doublequote-delimited string into output buffer obuf (allocated
593  * by caller, whose responsibility it is to ensure that it's big enough)
594  * cp points to the first char after the initial '"'
595  * Handles \ quoting
596  * Returns pointer to the first char after the terminating double quote, or
597  * NULL for error.
598  */
599 static const char *
600 http_parse_headerstring(const char *cp, char *obuf)
601 {
602 	for (;;) {
603 		switch (*cp) {
604 		case 0: /* Unterminated string */
605 			*obuf = 0;
606 			return (NULL);
607 		case '"': /* Ending quote */
608 			*obuf = 0;
609 			return (++cp);
610 		case '\\':
611 			if (*++cp == 0) {
612 				*obuf = 0;
613 				return (NULL);
614 			}
615 			/* FALLTHROUGH */
616 		default:
617 			*obuf++ = *cp++;
618 		}
619 	}
620 }
621 
622 /* Http auth challenge schemes */
623 typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
624 
625 /* Data holder for a Basic or Digest challenge. */
626 typedef struct {
627 	http_auth_schemes_t scheme;
628 	char	*realm;
629 	char	*qop;
630 	char	*nonce;
631 	char	*opaque;
632 	char	*algo;
633 	int	 stale;
634 	int	 nc; /* Nonce count */
635 } http_auth_challenge_t;
636 
637 static void
638 init_http_auth_challenge(http_auth_challenge_t *b)
639 {
640 	b->scheme = HTTPAS_UNKNOWN;
641 	b->realm = b->qop = b->nonce = b->opaque = b->algo = NULL;
642 	b->stale = b->nc = 0;
643 }
644 
645 static void
646 clean_http_auth_challenge(http_auth_challenge_t *b)
647 {
648 	if (b->realm)
649 		free(b->realm);
650 	if (b->qop)
651 		free(b->qop);
652 	if (b->nonce)
653 		free(b->nonce);
654 	if (b->opaque)
655 		free(b->opaque);
656 	if (b->algo)
657 		free(b->algo);
658 	init_http_auth_challenge(b);
659 }
660 
661 /* Data holder for an array of challenges offered in an http response. */
662 #define MAX_CHALLENGES 10
663 typedef struct {
664 	http_auth_challenge_t *challenges[MAX_CHALLENGES];
665 	int	count; /* Number of parsed challenges in the array */
666 	int	valid; /* We did parse an authenticate header */
667 } http_auth_challenges_t;
668 
669 static void
670 init_http_auth_challenges(http_auth_challenges_t *cs)
671 {
672 	int i;
673 	for (i = 0; i < MAX_CHALLENGES; i++)
674 		cs->challenges[i] = NULL;
675 	cs->count = cs->valid = 0;
676 }
677 
678 static void
679 clean_http_auth_challenges(http_auth_challenges_t *cs)
680 {
681 	int i;
682 	/* We rely on non-zero pointers being allocated, not on the count */
683 	for (i = 0; i < MAX_CHALLENGES; i++) {
684 		if (cs->challenges[i] != NULL) {
685 			clean_http_auth_challenge(cs->challenges[i]);
686 			free(cs->challenges[i]);
687 		}
688 	}
689 	init_http_auth_challenges(cs);
690 }
691 
692 /*
693  * Enumeration for lexical elements. Separators will be returned as their own
694  * ascii value
695  */
696 typedef enum {HTTPHL_WORD=256, HTTPHL_STRING=257, HTTPHL_END=258,
697 	      HTTPHL_ERROR = 259} http_header_lex_t;
698 
699 /*
700  * Determine what kind of token comes next and return possible value
701  * in buf, which is supposed to have been allocated big enough by
702  * caller. Advance input pointer and return element type.
703  */
704 static int
705 http_header_lex(const char **cpp, char *buf)
706 {
707 	size_t l;
708 	/* Eat initial whitespace */
709 	*cpp += strspn(*cpp, " \t");
710 	if (**cpp == 0)
711 		return (HTTPHL_END);
712 
713 	/* Separator ? */
714 	if (**cpp == ',' || **cpp == '=')
715 		return (*((*cpp)++));
716 
717 	/* String ? */
718 	if (**cpp == '"') {
719 		*cpp = http_parse_headerstring(++*cpp, buf);
720 		if (*cpp == NULL)
721 			return (HTTPHL_ERROR);
722 		return (HTTPHL_STRING);
723 	}
724 
725 	/* Read other token, until separator or whitespace */
726 	l = strcspn(*cpp, " \t,=");
727 	memcpy(buf, *cpp, l);
728 	buf[l] = 0;
729 	*cpp += l;
730 	return (HTTPHL_WORD);
731 }
732 
733 /*
734  * Read challenges from http xxx-authenticate header and accumulate them
735  * in the challenges list structure.
736  *
737  * Headers with multiple challenges are specified by rfc2617, but
738  * servers (ie: squid) often send them in separate headers instead,
739  * which in turn is forbidden by the http spec (multiple headers with
740  * the same name are only allowed for pure comma-separated lists, see
741  * rfc2616 sec 4.2).
742  *
743  * We support both approaches anyway
744  */
745 static int
746 http_parse_authenticate(const char *cp, http_auth_challenges_t *cs)
747 {
748 	int ret = -1;
749 	http_header_lex_t lex;
750 	char *key = malloc(strlen(cp) + 1);
751 	char *value = malloc(strlen(cp) + 1);
752 	char *buf = malloc(strlen(cp) + 1);
753 
754 	if (key == NULL || value == NULL || buf == NULL) {
755 		fetch_syserr();
756 		goto out;
757 	}
758 
759 	/* In any case we've seen the header and we set the valid bit */
760 	cs->valid = 1;
761 
762 	/* Need word first */
763 	lex = http_header_lex(&cp, key);
764 	if (lex != HTTPHL_WORD)
765 		goto out;
766 
767 	/* Loop on challenges */
768 	for (; cs->count < MAX_CHALLENGES; cs->count++) {
769 		cs->challenges[cs->count] =
770 			malloc(sizeof(http_auth_challenge_t));
771 		if (cs->challenges[cs->count] == NULL) {
772 			fetch_syserr();
773 			goto out;
774 		}
775 		init_http_auth_challenge(cs->challenges[cs->count]);
776 		if (!strcasecmp(key, "basic")) {
777 			cs->challenges[cs->count]->scheme = HTTPAS_BASIC;
778 		} else if (!strcasecmp(key, "digest")) {
779 			cs->challenges[cs->count]->scheme = HTTPAS_DIGEST;
780 		} else {
781 			cs->challenges[cs->count]->scheme = HTTPAS_UNKNOWN;
782 			/*
783 			 * Continue parsing as basic or digest may
784 			 * follow, and the syntax is the same for
785 			 * all. We'll just ignore this one when
786 			 * looking at the list
787 			 */
788 		}
789 
790 		/* Loop on attributes */
791 		for (;;) {
792 			/* Key */
793 			lex = http_header_lex(&cp, key);
794 			if (lex != HTTPHL_WORD)
795 				goto out;
796 
797 			/* Equal sign */
798 			lex = http_header_lex(&cp, buf);
799 			if (lex != '=')
800 				goto out;
801 
802 			/* Value */
803 			lex = http_header_lex(&cp, value);
804 			if (lex != HTTPHL_WORD && lex != HTTPHL_STRING)
805 				goto out;
806 
807 			if (!strcasecmp(key, "realm"))
808 				cs->challenges[cs->count]->realm =
809 					strdup(value);
810 			else if (!strcasecmp(key, "qop"))
811 				cs->challenges[cs->count]->qop =
812 					strdup(value);
813 			else if (!strcasecmp(key, "nonce"))
814 				cs->challenges[cs->count]->nonce =
815 					strdup(value);
816 			else if (!strcasecmp(key, "opaque"))
817 				cs->challenges[cs->count]->opaque =
818 					strdup(value);
819 			else if (!strcasecmp(key, "algorithm"))
820 				cs->challenges[cs->count]->algo =
821 					strdup(value);
822 			else if (!strcasecmp(key, "stale"))
823 				cs->challenges[cs->count]->stale =
824 					strcasecmp(value, "no");
825 			/* Else ignore unknown attributes */
826 
827 			/* Comma or Next challenge or End */
828 			lex = http_header_lex(&cp, key);
829 			/*
830 			 * If we get a word here, this is the beginning of the
831 			 * next challenge. Break the attributes loop
832 			 */
833 			if (lex == HTTPHL_WORD)
834 				break;
835 
836 			if (lex == HTTPHL_END) {
837 				/* End while looking for ',' is normal exit */
838 				cs->count++;
839 				ret = 0;
840 				goto out;
841 			}
842 			/* Anything else is an error */
843 			if (lex != ',')
844 				goto out;
845 
846 		} /* End attributes loop */
847 	} /* End challenge loop */
848 
849 	/*
850 	 * Challenges max count exceeded. This really can't happen
851 	 * with normal data, something's fishy -> error
852 	 */
853 
854 out:
855 	if (key)
856 		free(key);
857 	if (value)
858 		free(value);
859 	if (buf)
860 		free(buf);
861 	return (ret);
862 }
863 
864 
865 /*
866  * Parse a last-modified header
867  */
868 static int
869 http_parse_mtime(const char *p, time_t *mtime)
870 {
871 	char locale[64], *r;
872 	struct tm tm;
873 
874 	strncpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
875 	setlocale(LC_TIME, "C");
876 	r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
877 	/* XXX should add support for date-2 and date-3 */
878 	setlocale(LC_TIME, locale);
879 	if (r == NULL)
880 		return (-1);
881 	DEBUG(fprintf(stderr, "last modified: [%04d-%02d-%02d "
882 		  "%02d:%02d:%02d]\n",
883 		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
884 		  tm.tm_hour, tm.tm_min, tm.tm_sec));
885 	*mtime = timegm(&tm);
886 	return (0);
887 }
888 
889 /*
890  * Parse a content-length header
891  */
892 static int
893 http_parse_length(const char *p, off_t *length)
894 {
895 	off_t len;
896 
897 	for (len = 0; *p && isdigit((unsigned char)*p); ++p)
898 		len = len * 10 + (*p - '0');
899 	if (*p)
900 		return (-1);
901 	DEBUG(fprintf(stderr, "content length: [%lld]\n",
902 	    (long long)len));
903 	*length = len;
904 	return (0);
905 }
906 
907 /*
908  * Parse a content-range header
909  */
910 static int
911 http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
912 {
913 	off_t first, last, len;
914 
915 	if (strncasecmp(p, "bytes ", 6) != 0)
916 		return (-1);
917 	p += 6;
918 	if (*p == '*') {
919 		first = last = -1;
920 		++p;
921 	} else {
922 		for (first = 0; *p && isdigit((unsigned char)*p); ++p)
923 			first = first * 10 + *p - '0';
924 		if (*p != '-')
925 			return (-1);
926 		for (last = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
927 			last = last * 10 + *p - '0';
928 	}
929 	if (first > last || *p != '/')
930 		return (-1);
931 	for (len = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
932 		len = len * 10 + *p - '0';
933 	if (*p || len < last - first + 1)
934 		return (-1);
935 	if (first == -1) {
936 		DEBUG(fprintf(stderr, "content range: [*/%lld]\n",
937 		    (long long)len));
938 		*length = 0;
939 	} else {
940 		DEBUG(fprintf(stderr, "content range: [%lld-%lld/%lld]\n",
941 		    (long long)first, (long long)last, (long long)len));
942 		*length = last - first + 1;
943 	}
944 	*offset = first;
945 	*size = len;
946 	return (0);
947 }
948 
949 
950 /*****************************************************************************
951  * Helper functions for authorization
952  */
953 
954 /*
955  * Base64 encoding
956  */
957 static char *
958 http_base64(const char *src)
959 {
960 	static const char base64[] =
961 	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
962 	    "abcdefghijklmnopqrstuvwxyz"
963 	    "0123456789+/";
964 	char *str, *dst;
965 	size_t l;
966 	int t, r;
967 
968 	l = strlen(src);
969 	if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
970 		return (NULL);
971 	dst = str;
972 	r = 0;
973 
974 	while (l >= 3) {
975 		t = (src[0] << 16) | (src[1] << 8) | src[2];
976 		dst[0] = base64[(t >> 18) & 0x3f];
977 		dst[1] = base64[(t >> 12) & 0x3f];
978 		dst[2] = base64[(t >> 6) & 0x3f];
979 		dst[3] = base64[(t >> 0) & 0x3f];
980 		src += 3; l -= 3;
981 		dst += 4; r += 4;
982 	}
983 
984 	switch (l) {
985 	case 2:
986 		t = (src[0] << 16) | (src[1] << 8);
987 		dst[0] = base64[(t >> 18) & 0x3f];
988 		dst[1] = base64[(t >> 12) & 0x3f];
989 		dst[2] = base64[(t >> 6) & 0x3f];
990 		dst[3] = '=';
991 		dst += 4;
992 		r += 4;
993 		break;
994 	case 1:
995 		t = src[0] << 16;
996 		dst[0] = base64[(t >> 18) & 0x3f];
997 		dst[1] = base64[(t >> 12) & 0x3f];
998 		dst[2] = dst[3] = '=';
999 		dst += 4;
1000 		r += 4;
1001 		break;
1002 	case 0:
1003 		break;
1004 	}
1005 
1006 	*dst = 0;
1007 	return (str);
1008 }
1009 
1010 
1011 /*
1012  * Extract authorization parameters from environment value.
1013  * The value is like scheme:realm:user:pass
1014  */
1015 typedef struct {
1016 	char	*scheme;
1017 	char	*realm;
1018 	char	*user;
1019 	char	*password;
1020 } http_auth_params_t;
1021 
1022 static void
1023 init_http_auth_params(http_auth_params_t *s)
1024 {
1025 	s->scheme = s->realm = s->user = s->password = 0;
1026 }
1027 
1028 static void
1029 clean_http_auth_params(http_auth_params_t *s)
1030 {
1031 	if (s->scheme)
1032 		free(s->scheme);
1033 	if (s->realm)
1034 		free(s->realm);
1035 	if (s->user)
1036 		free(s->user);
1037 	if (s->password)
1038 		free(s->password);
1039 	init_http_auth_params(s);
1040 }
1041 
1042 static int
1043 http_authfromenv(const char *p, http_auth_params_t *parms)
1044 {
1045 	int ret = -1;
1046 	char *v, *ve;
1047 	char *str = strdup(p);
1048 
1049 	if (str == NULL) {
1050 		fetch_syserr();
1051 		return (-1);
1052 	}
1053 	v = str;
1054 
1055 	if ((ve = strchr(v, ':')) == NULL)
1056 		goto out;
1057 
1058 	*ve = 0;
1059 	if ((parms->scheme = strdup(v)) == NULL) {
1060 		fetch_syserr();
1061 		goto out;
1062 	}
1063 	v = ve + 1;
1064 
1065 	if ((ve = strchr(v, ':')) == NULL)
1066 		goto out;
1067 
1068 	*ve = 0;
1069 	if ((parms->realm = 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->user = strdup(v)) == NULL) {
1080 		fetch_syserr();
1081 		goto out;
1082 	}
1083 	v = ve + 1;
1084 
1085 
1086 	if ((parms->password = strdup(v)) == NULL) {
1087 		fetch_syserr();
1088 		goto out;
1089 	}
1090 	ret = 0;
1091 out:
1092 	if (ret == -1)
1093 		clean_http_auth_params(parms);
1094 	if (str)
1095 		free(str);
1096 	return (ret);
1097 }
1098 
1099 
1100 /*
1101  * Digest response: the code to compute the digest is taken from the
1102  * sample implementation in RFC2616
1103  */
1104 #define IN const
1105 #define OUT
1106 
1107 #define HASHLEN 16
1108 typedef char HASH[HASHLEN];
1109 #define HASHHEXLEN 32
1110 typedef char HASHHEX[HASHHEXLEN+1];
1111 
1112 static const char *hexchars = "0123456789abcdef";
1113 static void
1114 CvtHex(IN HASH Bin, OUT HASHHEX Hex)
1115 {
1116 	unsigned short i;
1117 	unsigned char j;
1118 
1119 	for (i = 0; i < HASHLEN; i++) {
1120 		j = (Bin[i] >> 4) & 0xf;
1121 		Hex[i*2] = hexchars[j];
1122 		j = Bin[i] & 0xf;
1123 		Hex[i*2+1] = hexchars[j];
1124 	};
1125 	Hex[HASHHEXLEN] = '\0';
1126 };
1127 
1128 /* calculate H(A1) as per spec */
1129 static void
1130 DigestCalcHA1(
1131 	IN char * pszAlg,
1132 	IN char * pszUserName,
1133 	IN char * pszRealm,
1134 	IN char * pszPassword,
1135 	IN char * pszNonce,
1136 	IN char * pszCNonce,
1137 	OUT HASHHEX SessionKey
1138 	)
1139 {
1140 	MD5_CTX Md5Ctx;
1141 	HASH HA1;
1142 
1143 	MD5Init(&Md5Ctx);
1144 	MD5Update(&Md5Ctx, pszUserName, strlen(pszUserName));
1145 	MD5Update(&Md5Ctx, ":", 1);
1146 	MD5Update(&Md5Ctx, pszRealm, strlen(pszRealm));
1147 	MD5Update(&Md5Ctx, ":", 1);
1148 	MD5Update(&Md5Ctx, pszPassword, strlen(pszPassword));
1149 	MD5Final(HA1, &Md5Ctx);
1150 	if (strcasecmp(pszAlg, "md5-sess") == 0) {
1151 
1152 		MD5Init(&Md5Ctx);
1153 		MD5Update(&Md5Ctx, HA1, HASHLEN);
1154 		MD5Update(&Md5Ctx, ":", 1);
1155 		MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1156 		MD5Update(&Md5Ctx, ":", 1);
1157 		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1158 		MD5Final(HA1, &Md5Ctx);
1159 	};
1160 	CvtHex(HA1, SessionKey);
1161 }
1162 
1163 /* calculate request-digest/response-digest as per HTTP Digest spec */
1164 static void
1165 DigestCalcResponse(
1166 	IN HASHHEX HA1,           /* H(A1) */
1167 	IN char * pszNonce,       /* nonce from server */
1168 	IN char * pszNonceCount,  /* 8 hex digits */
1169 	IN char * pszCNonce,      /* client nonce */
1170 	IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
1171 	IN char * pszMethod,      /* method from the request */
1172 	IN char * pszDigestUri,   /* requested URL */
1173 	IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
1174 	OUT HASHHEX Response      /* request-digest or response-digest */
1175 	)
1176 {
1177 /*	DEBUG(fprintf(stderr,
1178 		      "Calc: HA1[%s] Nonce[%s] qop[%s] method[%s] URI[%s]\n",
1179 		      HA1, pszNonce, pszQop, pszMethod, pszDigestUri));*/
1180 	MD5_CTX Md5Ctx;
1181 	HASH HA2;
1182 	HASH RespHash;
1183 	HASHHEX HA2Hex;
1184 
1185 	// calculate H(A2)
1186 	MD5Init(&Md5Ctx);
1187 	MD5Update(&Md5Ctx, pszMethod, strlen(pszMethod));
1188 	MD5Update(&Md5Ctx, ":", 1);
1189 	MD5Update(&Md5Ctx, pszDigestUri, strlen(pszDigestUri));
1190 	if (strcasecmp(pszQop, "auth-int") == 0) {
1191 		MD5Update(&Md5Ctx, ":", 1);
1192 		MD5Update(&Md5Ctx, HEntity, HASHHEXLEN);
1193 	};
1194 	MD5Final(HA2, &Md5Ctx);
1195 	CvtHex(HA2, HA2Hex);
1196 
1197 	// calculate response
1198 	MD5Init(&Md5Ctx);
1199 	MD5Update(&Md5Ctx, HA1, HASHHEXLEN);
1200 	MD5Update(&Md5Ctx, ":", 1);
1201 	MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1202 	MD5Update(&Md5Ctx, ":", 1);
1203 	if (*pszQop) {
1204 		MD5Update(&Md5Ctx, pszNonceCount, strlen(pszNonceCount));
1205 		MD5Update(&Md5Ctx, ":", 1);
1206 		MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1207 		MD5Update(&Md5Ctx, ":", 1);
1208 		MD5Update(&Md5Ctx, pszQop, strlen(pszQop));
1209 		MD5Update(&Md5Ctx, ":", 1);
1210 	};
1211 	MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
1212 	MD5Final(RespHash, &Md5Ctx);
1213 	CvtHex(RespHash, Response);
1214 }
1215 
1216 /*
1217  * Generate/Send a Digest authorization header
1218  * This looks like: [Proxy-]Authorization: credentials
1219  *
1220  *  credentials      = "Digest" digest-response
1221  *  digest-response  = 1#( username | realm | nonce | digest-uri
1222  *                      | response | [ algorithm ] | [cnonce] |
1223  *                      [opaque] | [message-qop] |
1224  *                          [nonce-count]  | [auth-param] )
1225  *  username         = "username" "=" username-value
1226  *  username-value   = quoted-string
1227  *  digest-uri       = "uri" "=" digest-uri-value
1228  *  digest-uri-value = request-uri   ; As specified by HTTP/1.1
1229  *  message-qop      = "qop" "=" qop-value
1230  *  cnonce           = "cnonce" "=" cnonce-value
1231  *  cnonce-value     = nonce-value
1232  *  nonce-count      = "nc" "=" nc-value
1233  *  nc-value         = 8LHEX
1234  *  response         = "response" "=" request-digest
1235  *  request-digest = <"> 32LHEX <">
1236  */
1237 static int
1238 http_digest_auth(conn_t *conn, const char *hdr, http_auth_challenge_t *c,
1239 		 http_auth_params_t *parms, struct url *url)
1240 {
1241 	int r;
1242 	char noncecount[10];
1243 	char cnonce[40];
1244 	char *options = 0;
1245 
1246 	if (!c->realm || !c->nonce) {
1247 		DEBUG(fprintf(stderr, "realm/nonce not set in challenge\n"));
1248 		return(-1);
1249 	}
1250 	if (!c->algo)
1251 		c->algo = strdup("");
1252 
1253 	if (asprintf(&options, "%s%s%s%s",
1254 		     *c->algo? ",algorithm=" : "", c->algo,
1255 		     c->opaque? ",opaque=" : "", c->opaque?c->opaque:"")== -1)
1256 		return (-1);
1257 
1258 	if (!c->qop) {
1259 		c->qop = strdup("");
1260 		*noncecount = 0;
1261 		*cnonce = 0;
1262 	} else {
1263 		c->nc++;
1264 		sprintf(noncecount, "%08x", c->nc);
1265 		/* We don't try very hard with the cnonce ... */
1266 		sprintf(cnonce, "%x%lx", getpid(), (unsigned long)time(0));
1267 	}
1268 
1269 	HASHHEX HA1;
1270 	DigestCalcHA1(c->algo, parms->user, c->realm,
1271 		      parms->password, c->nonce, cnonce, HA1);
1272 	DEBUG(fprintf(stderr, "HA1: [%s]\n", HA1));
1273 	HASHHEX digest;
1274 	DigestCalcResponse(HA1, c->nonce, noncecount, cnonce, c->qop,
1275 			   "GET", url->doc, "", digest);
1276 
1277 	if (c->qop[0]) {
1278 		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1279 			     "nonce=\"%s\",uri=\"%s\",response=\"%s\","
1280 			     "qop=\"auth\", cnonce=\"%s\", nc=%s%s",
1281 			     hdr, parms->user, c->realm,
1282 			     c->nonce, url->doc, digest,
1283 			     cnonce, noncecount, options);
1284 	} else {
1285 		r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1286 			     "nonce=\"%s\",uri=\"%s\",response=\"%s\"%s",
1287 			     hdr, parms->user, c->realm,
1288 			     c->nonce, url->doc, digest, options);
1289 	}
1290 	if (options)
1291 		free(options);
1292 	return (r);
1293 }
1294 
1295 /*
1296  * Encode username and password
1297  */
1298 static int
1299 http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
1300 {
1301 	char *upw, *auth;
1302 	int r;
1303 
1304 	DEBUG(fprintf(stderr, "basic: usr: [%s]\n", usr));
1305 	DEBUG(fprintf(stderr, "basic: pwd: [%s]\n", pwd));
1306 	if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
1307 		return (-1);
1308 	auth = http_base64(upw);
1309 	free(upw);
1310 	if (auth == NULL)
1311 		return (-1);
1312 	r = http_cmd(conn, "%s: Basic %s", hdr, auth);
1313 	free(auth);
1314 	return (r);
1315 }
1316 
1317 /*
1318  * Chose the challenge to answer and call the appropriate routine to
1319  * produce the header.
1320  */
1321 static int
1322 http_authorize(conn_t *conn, const char *hdr, http_auth_challenges_t *cs,
1323 	       http_auth_params_t *parms, struct url *url)
1324 {
1325 	http_auth_challenge_t *basic = NULL;
1326 	http_auth_challenge_t *digest = NULL;
1327 	int i;
1328 
1329 	/* If user or pass are null we're not happy */
1330 	if (!parms->user || !parms->password) {
1331 		DEBUG(fprintf(stderr, "NULL usr or pass\n"));
1332 		return (-1);
1333 	}
1334 
1335 	/* Look for a Digest and a Basic challenge */
1336 	for (i = 0; i < cs->count; i++) {
1337 		if (cs->challenges[i]->scheme == HTTPAS_BASIC)
1338 			basic = cs->challenges[i];
1339 		if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1340 			digest = cs->challenges[i];
1341 	}
1342 
1343 	/* Error if "Digest" was specified and there is no Digest challenge */
1344 	if (!digest && (parms->scheme &&
1345 			!strcasecmp(parms->scheme, "digest"))) {
1346 		DEBUG(fprintf(stderr,
1347 			      "Digest auth in env, not supported by peer\n"));
1348 		return (-1);
1349 	}
1350 	/*
1351 	 * If "basic" was specified in the environment, or there is no Digest
1352 	 * challenge, do the basic thing. Don't need a challenge for this,
1353 	 * so no need to check basic!=NULL
1354 	 */
1355 	if (!digest || (parms->scheme && !strcasecmp(parms->scheme,"basic")))
1356 		return (http_basic_auth(conn,hdr,parms->user,parms->password));
1357 
1358 	/* Else, prefer digest. We just checked that it's not NULL */
1359 	return (http_digest_auth(conn, hdr, digest, parms, url));
1360 }
1361 
1362 /*****************************************************************************
1363  * Helper functions for connecting to a server or proxy
1364  */
1365 
1366 /*
1367  * Connect to the correct HTTP server or proxy.
1368  */
1369 static conn_t *
1370 http_connect(struct url *URL, struct url *purl, const char *flags)
1371 {
1372 	struct url *curl;
1373 	conn_t *conn;
1374 	int verbose;
1375 	int af, val;
1376 
1377 #ifdef INET6
1378 	af = AF_UNSPEC;
1379 #else
1380 	af = AF_INET;
1381 #endif
1382 
1383 	verbose = CHECK_FLAG('v');
1384 	if (CHECK_FLAG('4'))
1385 		af = AF_INET;
1386 #ifdef INET6
1387 	else if (CHECK_FLAG('6'))
1388 		af = AF_INET6;
1389 #endif
1390 
1391 	curl = (purl != NULL) ? purl : URL;
1392 
1393 	if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1394 		/* fetch_connect() has already set an error code */
1395 		return (NULL);
1396 	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1397 		http_cmd(conn, "CONNECT %s:%d HTTP/1.1",
1398 		    URL->host, URL->port);
1399 		http_cmd(conn, "Host: %s:%d",
1400 		    URL->host, URL->port);
1401 		http_cmd(conn, "");
1402 		if (http_get_reply(conn) != HTTP_OK) {
1403 			fetch_close(conn);
1404 			return (NULL);
1405 		}
1406 		http_get_reply(conn);
1407 	}
1408 	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1409 	    fetch_ssl(conn, URL, verbose) == -1) {
1410 		fetch_close(conn);
1411 		/* grrr */
1412 		errno = EAUTH;
1413 		fetch_syserr();
1414 		return (NULL);
1415 	}
1416 
1417 	val = 1;
1418 	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1419 
1420 	return (conn);
1421 }
1422 
1423 static struct url *
1424 http_get_proxy(struct url * url, const char *flags)
1425 {
1426 	struct url *purl;
1427 	char *p;
1428 
1429 	if (flags != NULL && strchr(flags, 'd') != NULL)
1430 		return (NULL);
1431 	if (fetch_no_proxy_match(url->host))
1432 		return (NULL);
1433 	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1434 	    *p && (purl = fetchParseURL(p))) {
1435 		if (!*purl->scheme)
1436 			strcpy(purl->scheme, SCHEME_HTTP);
1437 		if (!purl->port)
1438 			purl->port = fetch_default_proxy_port(purl->scheme);
1439 		if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1440 			return (purl);
1441 		fetchFreeURL(purl);
1442 	}
1443 	return (NULL);
1444 }
1445 
1446 static void
1447 http_print_html(FILE *out, FILE *in)
1448 {
1449 	size_t len;
1450 	char *line, *p, *q;
1451 	int comment, tag;
1452 
1453 	comment = tag = 0;
1454 	while ((line = fgetln(in, &len)) != NULL) {
1455 		while (len && isspace((unsigned char)line[len - 1]))
1456 			--len;
1457 		for (p = q = line; q < line + len; ++q) {
1458 			if (comment && *q == '-') {
1459 				if (q + 2 < line + len &&
1460 				    strcmp(q, "-->") == 0) {
1461 					tag = comment = 0;
1462 					q += 2;
1463 				}
1464 			} else if (tag && !comment && *q == '>') {
1465 				p = q + 1;
1466 				tag = 0;
1467 			} else if (!tag && *q == '<') {
1468 				if (q > p)
1469 					fwrite(p, q - p, 1, out);
1470 				tag = 1;
1471 				if (q + 3 < line + len &&
1472 				    strcmp(q, "<!--") == 0) {
1473 					comment = 1;
1474 					q += 3;
1475 				}
1476 			}
1477 		}
1478 		if (!tag && q > p)
1479 			fwrite(p, q - p, 1, out);
1480 		fputc('\n', out);
1481 	}
1482 }
1483 
1484 
1485 /*****************************************************************************
1486  * Core
1487  */
1488 
1489 /*
1490  * Send a request and process the reply
1491  *
1492  * XXX This function is way too long, the do..while loop should be split
1493  * XXX off into a separate function.
1494  */
1495 FILE *
1496 http_request(struct url *URL, const char *op, struct url_stat *us,
1497 	struct url *purl, const char *flags)
1498 {
1499 	char timebuf[80];
1500 	char hbuf[MAXHOSTNAMELEN + 7], *host;
1501 	conn_t *conn;
1502 	struct url *url, *new;
1503 	int chunked, direct, ims, noredirect, verbose;
1504 	int e, i, n, val;
1505 	off_t offset, clength, length, size;
1506 	time_t mtime;
1507 	const char *p;
1508 	FILE *f;
1509 	hdr_t h;
1510 	struct tm *timestruct;
1511 	http_headerbuf_t headerbuf;
1512 	http_auth_challenges_t server_challenges;
1513 	http_auth_challenges_t proxy_challenges;
1514 
1515 	/* The following calls don't allocate anything */
1516 	init_http_headerbuf(&headerbuf);
1517 	init_http_auth_challenges(&server_challenges);
1518 	init_http_auth_challenges(&proxy_challenges);
1519 
1520 	direct = CHECK_FLAG('d');
1521 	noredirect = CHECK_FLAG('A');
1522 	verbose = CHECK_FLAG('v');
1523 	ims = CHECK_FLAG('i');
1524 
1525 	if (direct && purl) {
1526 		fetchFreeURL(purl);
1527 		purl = NULL;
1528 	}
1529 
1530 	/* try the provided URL first */
1531 	url = URL;
1532 
1533 	n = MAX_REDIRECT;
1534 	i = 0;
1535 
1536 	e = HTTP_PROTOCOL_ERROR;
1537 	do {
1538 		new = NULL;
1539 		chunked = 0;
1540 		offset = 0;
1541 		clength = -1;
1542 		length = -1;
1543 		size = -1;
1544 		mtime = 0;
1545 
1546 		/* check port */
1547 		if (!url->port)
1548 			url->port = fetch_default_port(url->scheme);
1549 
1550 		/* were we redirected to an FTP URL? */
1551 		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1552 			if (strcmp(op, "GET") == 0)
1553 				return (ftp_request(url, "RETR", us, purl, flags));
1554 			else if (strcmp(op, "HEAD") == 0)
1555 				return (ftp_request(url, "STAT", us, purl, flags));
1556 		}
1557 
1558 		/* connect to server or proxy */
1559 		if ((conn = http_connect(url, purl, flags)) == NULL)
1560 			goto ouch;
1561 
1562 		host = url->host;
1563 #ifdef INET6
1564 		if (strchr(url->host, ':')) {
1565 			snprintf(hbuf, sizeof(hbuf), "[%s]", url->host);
1566 			host = hbuf;
1567 		}
1568 #endif
1569 		if (url->port != fetch_default_port(url->scheme)) {
1570 			if (host != hbuf) {
1571 				strcpy(hbuf, host);
1572 				host = hbuf;
1573 			}
1574 			snprintf(hbuf + strlen(hbuf),
1575 			    sizeof(hbuf) - strlen(hbuf), ":%d", url->port);
1576 		}
1577 
1578 		/* send request */
1579 		if (verbose)
1580 			fetch_info("requesting %s://%s%s",
1581 			    url->scheme, host, url->doc);
1582 		if (purl && strcasecmp(URL->scheme, SCHEME_HTTPS) != 0) {
1583 			http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1584 			    op, url->scheme, host, url->doc);
1585 		} else {
1586 			http_cmd(conn, "%s %s HTTP/1.1",
1587 			    op, url->doc);
1588 		}
1589 
1590 		if (ims && url->ims_time) {
1591 			timestruct = gmtime((time_t *)&url->ims_time);
1592 			(void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1593 			    timestruct);
1594 			if (verbose)
1595 				fetch_info("If-Modified-Since: %s", timebuf);
1596 			http_cmd(conn, "If-Modified-Since: %s", timebuf);
1597 		}
1598 		/* virtual host */
1599 		http_cmd(conn, "Host: %s", host);
1600 
1601 		/*
1602 		 * Proxy authorization: we only send auth after we received
1603 		 * a 407 error. We do not first try basic anyway (changed
1604 		 * when support was added for digest-auth)
1605 		 */
1606 		if (purl && proxy_challenges.valid) {
1607 			http_auth_params_t aparams;
1608 			init_http_auth_params(&aparams);
1609 			if (*purl->user || *purl->pwd) {
1610 				aparams.user = purl->user ?
1611 					strdup(purl->user) : strdup("");
1612 				aparams.password = purl->pwd?
1613 					strdup(purl->pwd) : strdup("");
1614 			} else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1615 				   *p != '\0') {
1616 				if (http_authfromenv(p, &aparams) < 0) {
1617 					http_seterr(HTTP_NEED_PROXY_AUTH);
1618 					goto ouch;
1619 				}
1620 			}
1621 			http_authorize(conn, "Proxy-Authorization",
1622 				       &proxy_challenges, &aparams, url);
1623 			clean_http_auth_params(&aparams);
1624 		}
1625 
1626 		/*
1627 		 * Server authorization: we never send "a priori"
1628 		 * Basic auth, which used to be done if user/pass were
1629 		 * set in the url. This would be weird because we'd send the
1630 		 * password in the clear even if Digest is finally to be
1631 		 * used (it would have made more sense for the
1632 		 * pre-digest version to do this when Basic was specified
1633 		 * in the environment)
1634 		 */
1635 		if (server_challenges.valid) {
1636 			http_auth_params_t aparams;
1637 			init_http_auth_params(&aparams);
1638 			if (*url->user || *url->pwd) {
1639 				aparams.user = url->user ?
1640 					strdup(url->user) : strdup("");
1641 				aparams.password = url->pwd ?
1642 					strdup(url->pwd) : strdup("");
1643 			} else if ((p = getenv("HTTP_AUTH")) != NULL &&
1644 				   *p != '\0') {
1645 				if (http_authfromenv(p, &aparams) < 0) {
1646 					http_seterr(HTTP_NEED_AUTH);
1647 					goto ouch;
1648 				}
1649 			} else if (fetchAuthMethod &&
1650 				   fetchAuthMethod(url) == 0) {
1651 				aparams.user = url->user ?
1652 					strdup(url->user) : strdup("");
1653 				aparams.password = url->pwd ?
1654 					strdup(url->pwd) : strdup("");
1655 			} else {
1656 				http_seterr(HTTP_NEED_AUTH);
1657 				goto ouch;
1658 			}
1659 			http_authorize(conn, "Authorization",
1660 				       &server_challenges, &aparams, url);
1661 			clean_http_auth_params(&aparams);
1662 		}
1663 
1664 		/* other headers */
1665 		if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1666 			if (*p != '\0')
1667 				http_cmd(conn, "Accept: %s", p);
1668 		} else {
1669 			http_cmd(conn, "Accept: */*");
1670 		}
1671 		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1672 			if (strcasecmp(p, "auto") == 0)
1673 				http_cmd(conn, "Referer: %s://%s%s",
1674 				    url->scheme, host, url->doc);
1675 			else
1676 				http_cmd(conn, "Referer: %s", p);
1677 		}
1678 		if ((p = getenv("HTTP_USER_AGENT")) != NULL && *p != '\0')
1679 			http_cmd(conn, "User-Agent: %s", p);
1680 		else
1681 			http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER, getprogname());
1682 		if (url->offset > 0)
1683 			http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1684 		http_cmd(conn, "Connection: close");
1685 		http_cmd(conn, "");
1686 
1687 		/*
1688 		 * Force the queued request to be dispatched.  Normally, one
1689 		 * would do this with shutdown(2) but squid proxies can be
1690 		 * configured to disallow such half-closed connections.  To
1691 		 * be compatible with such configurations, fiddle with socket
1692 		 * options to force the pending data to be written.
1693 		 */
1694 		val = 0;
1695 		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1696 			   sizeof(val));
1697 		val = 1;
1698 		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1699 			   sizeof(val));
1700 
1701 		/* get reply */
1702 		switch (http_get_reply(conn)) {
1703 		case HTTP_OK:
1704 		case HTTP_PARTIAL:
1705 		case HTTP_NOT_MODIFIED:
1706 			/* fine */
1707 			break;
1708 		case HTTP_MOVED_PERM:
1709 		case HTTP_MOVED_TEMP:
1710 		case HTTP_SEE_OTHER:
1711 		case HTTP_USE_PROXY:
1712 			/*
1713 			 * Not so fine, but we still have to read the
1714 			 * headers to get the new location.
1715 			 */
1716 			break;
1717 		case HTTP_NEED_AUTH:
1718 			if (server_challenges.valid) {
1719 				/*
1720 				 * We already sent out authorization code,
1721 				 * so there's nothing more we can do.
1722 				 */
1723 				http_seterr(conn->err);
1724 				goto ouch;
1725 			}
1726 			/* try again, but send the password this time */
1727 			if (verbose)
1728 				fetch_info("server requires authorization");
1729 			break;
1730 		case HTTP_NEED_PROXY_AUTH:
1731 			if (proxy_challenges.valid) {
1732 				/*
1733 				 * We already sent our proxy
1734 				 * authorization code, so there's
1735 				 * nothing more we can do. */
1736 				http_seterr(conn->err);
1737 				goto ouch;
1738 			}
1739 			/* try again, but send the password this time */
1740 			if (verbose)
1741 				fetch_info("proxy requires authorization");
1742 			break;
1743 		case HTTP_BAD_RANGE:
1744 			/*
1745 			 * This can happen if we ask for 0 bytes because
1746 			 * we already have the whole file.  Consider this
1747 			 * a success for now, and check sizes later.
1748 			 */
1749 			break;
1750 		case HTTP_PROTOCOL_ERROR:
1751 			/* fall through */
1752 		case -1:
1753 			fetch_syserr();
1754 			goto ouch;
1755 		default:
1756 			http_seterr(conn->err);
1757 			if (!verbose)
1758 				goto ouch;
1759 			/* fall through so we can get the full error message */
1760 		}
1761 
1762 		/* get headers. http_next_header expects one line readahead */
1763 		if (fetch_getln(conn) == -1) {
1764 			fetch_syserr();
1765 			goto ouch;
1766 		}
1767 		do {
1768 			switch ((h = http_next_header(conn, &headerbuf, &p))) {
1769 			case hdr_syserror:
1770 				fetch_syserr();
1771 				goto ouch;
1772 			case hdr_error:
1773 				http_seterr(HTTP_PROTOCOL_ERROR);
1774 				goto ouch;
1775 			case hdr_content_length:
1776 				http_parse_length(p, &clength);
1777 				break;
1778 			case hdr_content_range:
1779 				http_parse_range(p, &offset, &length, &size);
1780 				break;
1781 			case hdr_last_modified:
1782 				http_parse_mtime(p, &mtime);
1783 				break;
1784 			case hdr_location:
1785 				if (!HTTP_REDIRECT(conn->err))
1786 					break;
1787 				/*
1788 				 * if the A flag is set, we don't follow
1789 				 * temporary redirects.
1790 				 */
1791 				if (noredirect &&
1792 				    conn->err != HTTP_MOVED_PERM &&
1793 				    conn->err != HTTP_PERM_REDIRECT &&
1794 				    conn->err != HTTP_USE_PROXY) {
1795 					n = 1;
1796 					break;
1797 				}
1798 				if (new)
1799 					free(new);
1800 				if (verbose)
1801 					fetch_info("%d redirect to %s", conn->err, p);
1802 				if (*p == '/')
1803 					/* absolute path */
1804 					new = fetchMakeURL(url->scheme, url->host, url->port, p,
1805 					    url->user, url->pwd);
1806 				else
1807 					new = fetchParseURL(p);
1808 				if (new == NULL) {
1809 					/* XXX should set an error code */
1810 					DEBUG(fprintf(stderr, "failed to parse new URL\n"));
1811 					goto ouch;
1812 				}
1813 
1814 				/* Only copy credentials if the host matches */
1815 				if (!strcmp(new->host, url->host) && !*new->user && !*new->pwd) {
1816 					strcpy(new->user, url->user);
1817 					strcpy(new->pwd, url->pwd);
1818 				}
1819 				new->offset = url->offset;
1820 				new->length = url->length;
1821 				break;
1822 			case hdr_transfer_encoding:
1823 				/* XXX weak test*/
1824 				chunked = (strcasecmp(p, "chunked") == 0);
1825 				break;
1826 			case hdr_www_authenticate:
1827 				if (conn->err != HTTP_NEED_AUTH)
1828 					break;
1829 				if (http_parse_authenticate(p, &server_challenges) == 0)
1830 					++n;
1831 				break;
1832 			case hdr_proxy_authenticate:
1833 				if (conn->err != HTTP_NEED_PROXY_AUTH)
1834 					break;
1835 				if (http_parse_authenticate(p, &proxy_challenges) == 0)
1836 					++n;
1837 				break;
1838 			case hdr_end:
1839 				/* fall through */
1840 			case hdr_unknown:
1841 				/* ignore */
1842 				break;
1843 			}
1844 		} while (h > hdr_end);
1845 
1846 		/* we need to provide authentication */
1847 		if (conn->err == HTTP_NEED_AUTH ||
1848 		    conn->err == HTTP_NEED_PROXY_AUTH) {
1849 			e = conn->err;
1850 			if ((conn->err == HTTP_NEED_AUTH &&
1851 			     !server_challenges.valid) ||
1852 			    (conn->err == HTTP_NEED_PROXY_AUTH &&
1853 			     !proxy_challenges.valid)) {
1854 				/* 401/7 but no www/proxy-authenticate ?? */
1855 				DEBUG(fprintf(stderr, "401/7 and no auth header\n"));
1856 				goto ouch;
1857 			}
1858 			fetch_close(conn);
1859 			conn = NULL;
1860 			continue;
1861 		}
1862 
1863 		/* requested range not satisfiable */
1864 		if (conn->err == HTTP_BAD_RANGE) {
1865 			if (url->offset == size && url->length == 0) {
1866 				/* asked for 0 bytes; fake it */
1867 				offset = url->offset;
1868 				clength = -1;
1869 				conn->err = HTTP_OK;
1870 				break;
1871 			} else {
1872 				http_seterr(conn->err);
1873 				goto ouch;
1874 			}
1875 		}
1876 
1877 		/* we have a hit or an error */
1878 		if (conn->err == HTTP_OK
1879 		    || conn->err == HTTP_NOT_MODIFIED
1880 		    || conn->err == HTTP_PARTIAL
1881 		    || HTTP_ERROR(conn->err))
1882 			break;
1883 
1884 		/* all other cases: we got a redirect */
1885 		e = conn->err;
1886 		clean_http_auth_challenges(&server_challenges);
1887 		fetch_close(conn);
1888 		conn = NULL;
1889 		if (!new) {
1890 			DEBUG(fprintf(stderr, "redirect with no new location\n"));
1891 			break;
1892 		}
1893 		if (url != URL)
1894 			fetchFreeURL(url);
1895 		url = new;
1896 	} while (++i < n);
1897 
1898 	/* we failed, or ran out of retries */
1899 	if (conn == NULL) {
1900 		http_seterr(e);
1901 		goto ouch;
1902 	}
1903 
1904 	DEBUG(fprintf(stderr, "offset %lld, length %lld,"
1905 		  " size %lld, clength %lld\n",
1906 		  (long long)offset, (long long)length,
1907 		  (long long)size, (long long)clength));
1908 
1909 	if (conn->err == HTTP_NOT_MODIFIED) {
1910 		http_seterr(HTTP_NOT_MODIFIED);
1911 		return (NULL);
1912 	}
1913 
1914 	/* check for inconsistencies */
1915 	if (clength != -1 && length != -1 && clength != length) {
1916 		http_seterr(HTTP_PROTOCOL_ERROR);
1917 		goto ouch;
1918 	}
1919 	if (clength == -1)
1920 		clength = length;
1921 	if (clength != -1)
1922 		length = offset + clength;
1923 	if (length != -1 && size != -1 && length != size) {
1924 		http_seterr(HTTP_PROTOCOL_ERROR);
1925 		goto ouch;
1926 	}
1927 	if (size == -1)
1928 		size = length;
1929 
1930 	/* fill in stats */
1931 	if (us) {
1932 		us->size = size;
1933 		us->atime = us->mtime = mtime;
1934 	}
1935 
1936 	/* too far? */
1937 	if (URL->offset > 0 && offset > URL->offset) {
1938 		http_seterr(HTTP_PROTOCOL_ERROR);
1939 		goto ouch;
1940 	}
1941 
1942 	/* report back real offset and size */
1943 	URL->offset = offset;
1944 	URL->length = clength;
1945 
1946 	/* wrap it up in a FILE */
1947 	if ((f = http_funopen(conn, chunked)) == NULL) {
1948 		fetch_syserr();
1949 		goto ouch;
1950 	}
1951 
1952 	if (url != URL)
1953 		fetchFreeURL(url);
1954 	if (purl)
1955 		fetchFreeURL(purl);
1956 
1957 	if (HTTP_ERROR(conn->err)) {
1958 		http_print_html(stderr, f);
1959 		fclose(f);
1960 		f = NULL;
1961 	}
1962 	clean_http_headerbuf(&headerbuf);
1963 	clean_http_auth_challenges(&server_challenges);
1964 	clean_http_auth_challenges(&proxy_challenges);
1965 	return (f);
1966 
1967 ouch:
1968 	if (url != URL)
1969 		fetchFreeURL(url);
1970 	if (purl)
1971 		fetchFreeURL(purl);
1972 	if (conn != NULL)
1973 		fetch_close(conn);
1974 	clean_http_headerbuf(&headerbuf);
1975 	clean_http_auth_challenges(&server_challenges);
1976 	clean_http_auth_challenges(&proxy_challenges);
1977 	return (NULL);
1978 }
1979 
1980 
1981 /*****************************************************************************
1982  * Entry points
1983  */
1984 
1985 /*
1986  * Retrieve and stat a file by HTTP
1987  */
1988 FILE *
1989 fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
1990 {
1991 	return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
1992 }
1993 
1994 /*
1995  * Retrieve a file by HTTP
1996  */
1997 FILE *
1998 fetchGetHTTP(struct url *URL, const char *flags)
1999 {
2000 	return (fetchXGetHTTP(URL, NULL, flags));
2001 }
2002 
2003 /*
2004  * Store a file by HTTP
2005  */
2006 FILE *
2007 fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2008 {
2009 	warnx("fetchPutHTTP(): not implemented");
2010 	return (NULL);
2011 }
2012 
2013 /*
2014  * Get an HTTP document's metadata
2015  */
2016 int
2017 fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2018 {
2019 	FILE *f;
2020 
2021 	f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2022 	if (f == NULL)
2023 		return (-1);
2024 	fclose(f);
2025 	return (0);
2026 }
2027 
2028 /*
2029  * List a directory
2030  */
2031 struct url_ent *
2032 fetchListHTTP(struct url *url __unused, const char *flags __unused)
2033 {
2034 	warnx("fetchListHTTP(): not implemented");
2035 	return (NULL);
2036 }
2037