lib/libfetch/http.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 2000-2014 Dag-Erling Smørgrav
   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 __FBSDID("$FreeBSD$");
  33
  34 /*
  35  * The following copyright applies to the base64 code:
  36  *
  37  *-
  38  * Copyright 1997 Massachusetts Institute of Technology
  39  *
  40  * Permission to use, copy, modify, and distribute this software and
  41  * its documentation for any purpose and without fee is hereby
  42  * granted, provided that both the above copyright notice and this
  43  * permission notice appear in all copies, that both the above
  44  * copyright notice and this permission notice appear in all
  45  * supporting documentation, and that the name of M.I.T. not be used
  46  * in advertising or publicity pertaining to distribution of the
  47  * software without specific, written prior permission.  M.I.T. makes
  48  * no representations about the suitability of this software for any
  49  * purpose.  It is provided "as is" without express or implied
  50  * warranty.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
  53  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
  54  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  55  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
  56  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  57  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  58  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  59  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  60  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  61  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  62  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  63  * SUCH DAMAGE.
  64  */
  65
  66 #include <sys/param.h>
  67 #include <sys/socket.h>
  68 #include <sys/time.h>
  69
  70 #include <ctype.h>
  71 #include <err.h>
  72 #include <errno.h>
  73 #include <locale.h>
  74 #include <netdb.h>
  75 #include <stdarg.h>
  76 #include <stdbool.h>
  77 #include <stdio.h>
  78 #include <stdlib.h>
  79 #include <string.h>
  80 #include <time.h>
  81 #include <unistd.h>
  82
  83 #ifdef WITH_SSL
  84 #include <openssl/md5.h>
  85 #define MD5Init(c) MD5_Init(c)
  86 #define MD5Update(c, data, len) MD5_Update(c, data, len)
  87 #define MD5Final(md, c) MD5_Final(md, c)
  88 #else
  89 #include <md5.h>
  90 #endif
  91
  92 #include <netinet/in.h>
  93 #include <netinet/tcp.h>
  94
  95 #include "fetch.h"
  96 #include "common.h"
  97 #include "httperr.h"
  98
  99 /* Maximum number of redirects to follow */
 100 #define MAX_REDIRECT 20
 101
 102 /* Symbolic names for reply codes we care about */
 103 #define HTTP_OK                 200
 104 #define HTTP_PARTIAL            206
 105 #define HTTP_MOVED_PERM         301
 106 #define HTTP_MOVED_TEMP         302
 107 #define HTTP_SEE_OTHER          303
 108 #define HTTP_NOT_MODIFIED       304
 109 #define HTTP_USE_PROXY          305
 110 #define HTTP_TEMP_REDIRECT      307
 111 #define HTTP_PERM_REDIRECT      308
 112 #define HTTP_NEED_AUTH          401
 113 #define HTTP_NEED_PROXY_AUTH    407
 114 #define HTTP_BAD_RANGE          416
 115 #define HTTP_PROTOCOL_ERROR     999
 116
 117 #define HTTP_REDIRECT(xyz) ((xyz) == HTTP_MOVED_PERM \
 118                             || (xyz) == HTTP_MOVED_TEMP \
 119                             || (xyz) == HTTP_TEMP_REDIRECT \
 120                             || (xyz) == HTTP_PERM_REDIRECT \
 121                             || (xyz) == HTTP_USE_PROXY \
 122                             || (xyz) == HTTP_SEE_OTHER)
 123
 124 #define HTTP_ERROR(xyz) ((xyz) >= 400 && (xyz) <= 599)
 125
 126
 127 /*****************************************************************************
 128  * I/O functions for decoding chunked streams
 129  */
 130
 131 struct httpio
 132 {
 133         conn_t          *conn;          /* connection */
 134         int              chunked;       /* chunked mode */
 135         char            *buf;           /* chunk buffer */
 136         size_t           bufsize;       /* size of chunk buffer */
 137         size_t           buflen;        /* amount of data currently in buffer */
 138         size_t           bufpos;        /* current read offset in buffer */
 139         int              eof;           /* end-of-file flag */
 140         int              error;         /* error flag */
 141         size_t           chunksize;     /* remaining size of current chunk */
 142 #ifndef NDEBUG
 143         size_t           total;
 144 #endif
 145 };
 146
 147 /*
 148  * Get next chunk header
 149  */
 150 static int
 151 http_new_chunk(struct httpio *io)
 152 {
 153         char *p;
 154
 155         if (fetch_getln(io->conn) == -1)
 156                 return (-1);
 157
 158         if (io->conn->buflen < 2 || !isxdigit((unsigned char)*io->conn->buf))
 159                 return (-1);
 160
 161         for (p = io->conn->buf; *p && !isspace((unsigned char)*p); ++p) {
 162                 if (*p == ';')
 163                         break;
 164                 if (!isxdigit((unsigned char)*p))
 165                         return (-1);
 166                 if (isdigit((unsigned char)*p)) {
 167                         io->chunksize = io->chunksize * 16 +
 168                             *p - '0';
 169                 } else {
 170                         io->chunksize = io->chunksize * 16 +
 171                             10 + tolower((unsigned char)*p) - 'a';
 172                 }
 173         }
 174
 175 #ifndef NDEBUG
 176         if (fetchDebug) {
 177                 io->total += io->chunksize;
 178                 if (io->chunksize == 0)
 179                         fprintf(stderr, "%s(): end of last chunk\n", __func__);
 180                 else
 181                         fprintf(stderr, "%s(): new chunk: %lu (%lu)\n",
 182                             __func__, (unsigned long)io->chunksize,
 183                             (unsigned long)io->total);
 184         }
 185 #endif
 186
 187         return (io->chunksize);
 188 }
 189
 190 /*
 191  * Grow the input buffer to at least len bytes
 192  */
 193 static inline int
 194 http_growbuf(struct httpio *io, size_t len)
 195 {
 196         char *tmp;
 197
 198         if (io->bufsize >= len)
 199                 return (0);
 200
 201         if ((tmp = realloc(io->buf, len)) == NULL)
 202                 return (-1);
 203         io->buf = tmp;
 204         io->bufsize = len;
 205         return (0);
 206 }
 207
 208 /*
 209  * Fill the input buffer, do chunk decoding on the fly
 210  */
 211 static ssize_t
 212 http_fillbuf(struct httpio *io, size_t len)
 213 {
 214         ssize_t nbytes;
 215         char ch;
 216
 217         if (io->error)
 218                 return (-1);
 219         if (io->eof)
 220                 return (0);
 221
 222         /* not chunked: just fetch the requested amount */
 223         if (io->chunked == 0) {
 224                 if (http_growbuf(io, len) == -1)
 225                         return (-1);
 226                 if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
 227                         io->error = errno;
 228                         return (-1);
 229                 }
 230                 io->buflen = nbytes;
 231                 io->bufpos = 0;
 232                 return (io->buflen);
 233         }
 234
 235         /* chunked, but we ran out: get the next chunk header */
 236         if (io->chunksize == 0) {
 237                 switch (http_new_chunk(io)) {
 238                 case -1:
 239                         io->error = EPROTO;
 240                         return (-1);
 241                 case 0:
 242                         io->eof = 1;
 243                         return (0);
 244                 }
 245         }
 246
 247         /* fetch the requested amount, but no more than the current chunk */
 248         if (len > io->chunksize)
 249                 len = io->chunksize;
 250         if (http_growbuf(io, len) == -1)
 251                 return (-1);
 252         if ((nbytes = fetch_read(io->conn, io->buf, len)) == -1) {
 253                 io->error = errno;
 254                 return (-1);
 255         }
 256         io->bufpos = 0;
 257         io->buflen = nbytes;
 258         io->chunksize -= nbytes;
 259
 260         if (io->chunksize == 0) {
 261                 if (fetch_read(io->conn, &ch, 1) != 1 || ch != '\r' ||
 262                     fetch_read(io->conn, &ch, 1) != 1 || ch != '\n')
 263                         return (-1);
 264         }
 265
 266         return (io->buflen);
 267 }
 268
 269 /*
 270  * Read function
 271  */
 272 static int
 273 http_readfn(void *v, char *buf, int len)
 274 {
 275         struct httpio *io = (struct httpio *)v;
 276         int rlen;
 277
 278         if (io->error)
 279                 return (-1);
 280         if (io->eof)
 281                 return (0);
 282
 283         /* empty buffer */
 284         if (!io->buf || io->bufpos == io->buflen) {
 285                 if ((rlen = http_fillbuf(io, len)) < 0) {
 286                         if ((errno = io->error) == EINTR)
 287                                 io->error = 0;
 288                         return (-1);
 289                 } else if (rlen == 0) {
 290                         return (0);
 291                 }
 292         }
 293
 294         rlen = io->buflen - io->bufpos;
 295         if (len < rlen)
 296                 rlen = len;
 297         memcpy(buf, io->buf + io->bufpos, rlen);
 298         io->bufpos += rlen;
 299         return (rlen);
 300 }
 301
 302 /*
 303  * Write function
 304  */
 305 static int
 306 http_writefn(void *v, const char *buf, int len)
 307 {
 308         struct httpio *io = (struct httpio *)v;
 309
 310         return (fetch_write(io->conn, buf, len));
 311 }
 312
 313 /*
 314  * Close function
 315  */
 316 static int
 317 http_closefn(void *v)
 318 {
 319         struct httpio *io = (struct httpio *)v;
 320         int r;
 321
 322         r = fetch_close(io->conn);
 323         if (io->buf)
 324                 free(io->buf);
 325         free(io);
 326         return (r);
 327 }
 328
 329 /*
 330  * Wrap a file descriptor up
 331  */
 332 static FILE *
 333 http_funopen(conn_t *conn, int chunked)
 334 {
 335         struct httpio *io;
 336         FILE *f;
 337
 338         if ((io = calloc(1, sizeof(*io))) == NULL) {
 339                 fetch_syserr();
 340                 return (NULL);
 341         }
 342         io->conn = conn;
 343         io->chunked = chunked;
 344         f = funopen(io, http_readfn, http_writefn, NULL, http_closefn);
 345         if (f == NULL) {
 346                 fetch_syserr();
 347                 free(io);
 348                 return (NULL);
 349         }
 350         return (f);
 351 }
 352
 353
 354 /*****************************************************************************
 355  * Helper functions for talking to the server and parsing its replies
 356  */
 357
 358 /* Header types */
 359 typedef enum {
 360         hdr_syserror = -2,
 361         hdr_error = -1,
 362         hdr_end = 0,
 363         hdr_unknown = 1,
 364         hdr_content_length,
 365         hdr_content_range,
 366         hdr_last_modified,
 367         hdr_location,
 368         hdr_transfer_encoding,
 369         hdr_www_authenticate,
 370         hdr_proxy_authenticate,
 371 } hdr_t;
 372
 373 /* Names of interesting headers */
 374 static struct {
 375         hdr_t            num;
 376         const char      *name;
 377 } hdr_names[] = {
 378         { hdr_content_length,           "Content-Length" },
 379         { hdr_content_range,            "Content-Range" },
 380         { hdr_last_modified,            "Last-Modified" },
 381         { hdr_location,                 "Location" },
 382         { hdr_transfer_encoding,        "Transfer-Encoding" },
 383         { hdr_www_authenticate,         "WWW-Authenticate" },
 384         { hdr_proxy_authenticate,       "Proxy-Authenticate" },
 385         { hdr_unknown,                  NULL },
 386 };
 387
 388 /*
 389  * Send a formatted line; optionally echo to terminal
 390  */
 391 static int
 392 http_cmd(conn_t *conn, const char *fmt, ...)
 393 {
 394         va_list ap;
 395         size_t len;
 396         char *msg;
 397         int r;
 398
 399         va_start(ap, fmt);
 400         len = vasprintf(&msg, fmt, ap);
 401         va_end(ap);
 402
 403         if (msg == NULL) {
 404                 errno = ENOMEM;
 405                 fetch_syserr();
 406                 return (-1);
 407         }
 408
 409         r = fetch_putln(conn, msg, len);
 410         free(msg);
 411
 412         if (r == -1) {
 413                 fetch_syserr();
 414                 return (-1);
 415         }
 416
 417         return (0);
 418 }
 419
 420 /*
 421  * Get and parse status line
 422  */
 423 static int
 424 http_get_reply(conn_t *conn)
 425 {
 426         char *p;
 427
 428         if (fetch_getln(conn) == -1)
 429                 return (-1);
 430         /*
 431          * A valid status line looks like "HTTP/m.n xyz reason" where m
 432          * and n are the major and minor protocol version numbers and xyz
 433          * is the reply code.
 434          * Unfortunately, there are servers out there (NCSA 1.5.1, to name
 435          * just one) that do not send a version number, so we can't rely
 436          * on finding one, but if we do, insist on it being 1.0 or 1.1.
 437          * We don't care about the reason phrase.
 438          */
 439         if (strncmp(conn->buf, "HTTP", 4) != 0)
 440                 return (HTTP_PROTOCOL_ERROR);
 441         p = conn->buf + 4;
 442         if (*p == '/') {
 443                 if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
 444                         return (HTTP_PROTOCOL_ERROR);
 445                 p += 4;
 446         }
 447         if (*p != ' ' ||
 448             !isdigit((unsigned char)p[1]) ||
 449             !isdigit((unsigned char)p[2]) ||
 450             !isdigit((unsigned char)p[3]))
 451                 return (HTTP_PROTOCOL_ERROR);
 452
 453         conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
 454         return (conn->err);
 455 }
 456
 457 /*
 458  * Check a header; if the type matches the given string, return a pointer
 459  * to the beginning of the value.
 460  */
 461 static const char *
 462 http_match(const char *str, const char *hdr)
 463 {
 464         while (*str && *hdr &&
 465             tolower((unsigned char)*str++) == tolower((unsigned char)*hdr++))
 466                 /* nothing */;
 467         if (*str || *hdr != ':')
 468                 return (NULL);
 469         while (*hdr && isspace((unsigned char)*++hdr))
 470                 /* nothing */;
 471         return (hdr);
 472 }
 473
 474
 475 /*
 476  * Get the next header and return the appropriate symbolic code.  We
 477  * need to read one line ahead for checking for a continuation line
 478  * belonging to the current header (continuation lines start with
 479  * white space).
 480  *
 481  * We get called with a fresh line already in the conn buffer, either
 482  * from the previous http_next_header() invocation, or, the first
 483  * time, from a fetch_getln() performed by our caller.
 484  *
 485  * This stops when we encounter an empty line (we dont read beyond the header
 486  * area).
 487  *
 488  * Note that the "headerbuf" is just a place to return the result. Its
 489  * contents are not used for the next call. This means that no cleanup
 490  * is needed when ie doing another connection, just call the cleanup when
 491  * fully done to deallocate memory.
 492  */
 493
 494 /* Limit the max number of continuation lines to some reasonable value */
 495 #define HTTP_MAX_CONT_LINES 10
 496
 497 /* Place into which to build a header from one or several lines */
 498 typedef struct {
 499         char    *buf;           /* buffer */
 500         size_t   bufsize;       /* buffer size */
 501         size_t   buflen;        /* length of buffer contents */
 502 } http_headerbuf_t;
 503
 504 static void
 505 init_http_headerbuf(http_headerbuf_t *buf)
 506 {
 507         buf->buf = NULL;
 508         buf->bufsize = 0;
 509         buf->buflen = 0;
 510 }
 511
 512 static void
 513 clean_http_headerbuf(http_headerbuf_t *buf)
 514 {
 515         if (buf->buf)
 516                 free(buf->buf);
 517         init_http_headerbuf(buf);
 518 }
 519
 520 /* Remove whitespace at the end of the buffer */
 521 static void
 522 http_conn_trimright(conn_t *conn)
 523 {
 524         while (conn->buflen &&
 525                isspace((unsigned char)conn->buf[conn->buflen - 1]))
 526                 conn->buflen--;
 527         conn->buf[conn->buflen] = '\0';
 528 }
 529
 530 static hdr_t
 531 http_next_header(conn_t *conn, http_headerbuf_t *hbuf, const char **p)
 532 {
 533         unsigned int i, len;
 534
 535         /*
 536          * Have to do the stripping here because of the first line. So
 537          * it's done twice for the subsequent lines. No big deal
 538          */
 539         http_conn_trimright(conn);
 540         if (conn->buflen == 0)
 541                 return (hdr_end);
 542
 543         /* Copy the line to the headerbuf */
 544         if (hbuf->bufsize < conn->buflen + 1) {
 545                 if ((hbuf->buf = realloc(hbuf->buf, conn->buflen + 1)) == NULL)
 546                         return (hdr_syserror);
 547                 hbuf->bufsize = conn->buflen + 1;
 548         }
 549         strcpy(hbuf->buf, conn->buf);
 550         hbuf->buflen = conn->buflen;
 551
 552         /*
 553          * Fetch possible continuation lines. Stop at 1st non-continuation
 554          * and leave it in the conn buffer
 555          */
 556         for (i = 0; i < HTTP_MAX_CONT_LINES; i++) {
 557                 if (fetch_getln(conn) == -1)
 558                         return (hdr_syserror);
 559
 560                 /*
 561                  * Note: we carry on the idea from the previous version
 562                  * that a pure whitespace line is equivalent to an empty
 563                  * one (so it's not continuation and will be handled when
 564                  * we are called next)
 565                  */
 566                 http_conn_trimright(conn);
 567                 if (conn->buf[0] != ' ' && conn->buf[0] != "\t"[0])
 568                         break;
 569
 570                 /* Got a continuation line. Concatenate to previous */
 571                 len = hbuf->buflen + conn->buflen;
 572                 if (hbuf->bufsize < len + 1) {
 573                         len *= 2;
 574                         if ((hbuf->buf = realloc(hbuf->buf, len + 1)) == NULL)
 575                                 return (hdr_syserror);
 576                         hbuf->bufsize = len + 1;
 577                 }
 578                 strcpy(hbuf->buf + hbuf->buflen, conn->buf);
 579                 hbuf->buflen += conn->buflen;
 580         }
 581
 582         /*
 583          * We could check for malformed headers but we don't really care.
 584          * A valid header starts with a token immediately followed by a
 585          * colon; a token is any sequence of non-control, non-whitespace
 586          * characters except "()<>@,;:\\\"{}".
 587          */
 588         for (i = 0; hdr_names[i].num != hdr_unknown; i++)
 589                 if ((*p = http_match(hdr_names[i].name, hbuf->buf)) != NULL)
 590                         return (hdr_names[i].num);
 591
 592         return (hdr_unknown);
 593 }
 594
 595 /**************************
 596  * [Proxy-]Authenticate header parsing
 597  */
 598
 599 /*
 600  * Read doublequote-delimited string into output buffer obuf (allocated
 601  * by caller, whose responsibility it is to ensure that it's big enough)
 602  * cp points to the first char after the initial '"'
 603  * Handles \ quoting
 604  * Returns pointer to the first char after the terminating double quote, or
 605  * NULL for error.
 606  */
 607 static const char *
 608 http_parse_headerstring(const char *cp, char *obuf)
 609 {
 610         for (;;) {
 611                 switch (*cp) {
 612                 case 0: /* Unterminated string */
 613                         *obuf = 0;
 614                         return (NULL);
 615                 case '"': /* Ending quote */
 616                         *obuf = 0;
 617                         return (++cp);
 618                 case '\\':
 619                         if (*++cp == 0) {
 620                                 *obuf = 0;
 621                                 return (NULL);
 622                         }
 623                         /* FALLTHROUGH */
 624                 default:
 625                         *obuf++ = *cp++;
 626                 }
 627         }
 628 }
 629
 630 /* Http auth challenge schemes */
 631 typedef enum {HTTPAS_UNKNOWN, HTTPAS_BASIC,HTTPAS_DIGEST} http_auth_schemes_t;
 632
 633 /* Data holder for a Basic or Digest challenge. */
 634 typedef struct {
 635         http_auth_schemes_t scheme;
 636         char    *realm;
 637         char    *qop;
 638         char    *nonce;
 639         char    *opaque;
 640         char    *algo;
 641         int      stale;
 642         int      nc; /* Nonce count */
 643 } http_auth_challenge_t;
 644
 645 static void
 646 init_http_auth_challenge(http_auth_challenge_t *b)
 647 {
 648         b->scheme = HTTPAS_UNKNOWN;
 649         b->realm = b->qop = b->nonce = b->opaque = b->algo = NULL;
 650         b->stale = b->nc = 0;
 651 }
 652
 653 static void
 654 clean_http_auth_challenge(http_auth_challenge_t *b)
 655 {
 656         if (b->realm)
 657                 free(b->realm);
 658         if (b->qop)
 659                 free(b->qop);
 660         if (b->nonce)
 661                 free(b->nonce);
 662         if (b->opaque)
 663                 free(b->opaque);
 664         if (b->algo)
 665                 free(b->algo);
 666         init_http_auth_challenge(b);
 667 }
 668
 669 /* Data holder for an array of challenges offered in an http response. */
 670 #define MAX_CHALLENGES 10
 671 typedef struct {
 672         http_auth_challenge_t *challenges[MAX_CHALLENGES];
 673         int     count; /* Number of parsed challenges in the array */
 674         int     valid; /* We did parse an authenticate header */
 675 } http_auth_challenges_t;
 676
 677 static void
 678 init_http_auth_challenges(http_auth_challenges_t *cs)
 679 {
 680         int i;
 681         for (i = 0; i < MAX_CHALLENGES; i++)
 682                 cs->challenges[i] = NULL;
 683         cs->count = cs->valid = 0;
 684 }
 685
 686 static void
 687 clean_http_auth_challenges(http_auth_challenges_t *cs)
 688 {
 689         int i;
 690         /* We rely on non-zero pointers being allocated, not on the count */
 691         for (i = 0; i < MAX_CHALLENGES; i++) {
 692                 if (cs->challenges[i] != NULL) {
 693                         clean_http_auth_challenge(cs->challenges[i]);
 694                         free(cs->challenges[i]);
 695                 }
 696         }
 697         init_http_auth_challenges(cs);
 698 }
 699
 700 /*
 701  * Enumeration for lexical elements. Separators will be returned as their own
 702  * ascii value
 703  */
 704 typedef enum {HTTPHL_WORD=256, HTTPHL_STRING=257, HTTPHL_END=258,
 705               HTTPHL_ERROR = 259} http_header_lex_t;
 706
 707 /*
 708  * Determine what kind of token comes next and return possible value
 709  * in buf, which is supposed to have been allocated big enough by
 710  * caller. Advance input pointer and return element type.
 711  */
 712 static int
 713 http_header_lex(const char **cpp, char *buf)
 714 {
 715         size_t l;
 716         /* Eat initial whitespace */
 717         *cpp += strspn(*cpp, " \t");
 718         if (**cpp == 0)
 719                 return (HTTPHL_END);
 720
 721         /* Separator ? */
 722         if (**cpp == ',' || **cpp == '=')
 723                 return (*((*cpp)++));
 724
 725         /* String ? */
 726         if (**cpp == '"') {
 727                 *cpp = http_parse_headerstring(++*cpp, buf);
 728                 if (*cpp == NULL)
 729                         return (HTTPHL_ERROR);
 730                 return (HTTPHL_STRING);
 731         }
 732
 733         /* Read other token, until separator or whitespace */
 734         l = strcspn(*cpp, " \t,=");
 735         memcpy(buf, *cpp, l);
 736         buf[l] = 0;
 737         *cpp += l;
 738         return (HTTPHL_WORD);
 739 }
 740
 741 /*
 742  * Read challenges from http xxx-authenticate header and accumulate them
 743  * in the challenges list structure.
 744  *
 745  * Headers with multiple challenges are specified by rfc2617, but
 746  * servers (ie: squid) often send them in separate headers instead,
 747  * which in turn is forbidden by the http spec (multiple headers with
 748  * the same name are only allowed for pure comma-separated lists, see
 749  * rfc2616 sec 4.2).
 750  *
 751  * We support both approaches anyway
 752  */
 753 static int
 754 http_parse_authenticate(const char *cp, http_auth_challenges_t *cs)
 755 {
 756         int ret = -1;
 757         http_header_lex_t lex;
 758         char *key = malloc(strlen(cp) + 1);
 759         char *value = malloc(strlen(cp) + 1);
 760         char *buf = malloc(strlen(cp) + 1);
 761
 762         if (key == NULL || value == NULL || buf == NULL) {
 763                 fetch_syserr();
 764                 goto out;
 765         }
 766
 767         /* In any case we've seen the header and we set the valid bit */
 768         cs->valid = 1;
 769
 770         /* Need word first */
 771         lex = http_header_lex(&cp, key);
 772         if (lex != HTTPHL_WORD)
 773                 goto out;
 774
 775         /* Loop on challenges */
 776         for (; cs->count < MAX_CHALLENGES; cs->count++) {
 777                 cs->challenges[cs->count] =
 778                         malloc(sizeof(http_auth_challenge_t));
 779                 if (cs->challenges[cs->count] == NULL) {
 780                         fetch_syserr();
 781                         goto out;
 782                 }
 783                 init_http_auth_challenge(cs->challenges[cs->count]);
 784                 if (strcasecmp(key, "basic") == 0) {
 785                         cs->challenges[cs->count]->scheme = HTTPAS_BASIC;
 786                 } else if (strcasecmp(key, "digest") == 0) {
 787                         cs->challenges[cs->count]->scheme = HTTPAS_DIGEST;
 788                 } else {
 789                         cs->challenges[cs->count]->scheme = HTTPAS_UNKNOWN;
 790                         /*
 791                          * Continue parsing as basic or digest may
 792                          * follow, and the syntax is the same for
 793                          * all. We'll just ignore this one when
 794                          * looking at the list
 795                          */
 796                 }
 797
 798                 /* Loop on attributes */
 799                 for (;;) {
 800                         /* Key */
 801                         lex = http_header_lex(&cp, key);
 802                         if (lex != HTTPHL_WORD)
 803                                 goto out;
 804
 805                         /* Equal sign */
 806                         lex = http_header_lex(&cp, buf);
 807                         if (lex != '=')
 808                                 goto out;
 809
 810                         /* Value */
 811                         lex = http_header_lex(&cp, value);
 812                         if (lex != HTTPHL_WORD && lex != HTTPHL_STRING)
 813                                 goto out;
 814
 815                         if (strcasecmp(key, "realm") == 0) {
 816                                 cs->challenges[cs->count]->realm =
 817                                     strdup(value);
 818                         } else if (strcasecmp(key, "qop") == 0) {
 819                                 cs->challenges[cs->count]->qop =
 820                                     strdup(value);
 821                         } else if (strcasecmp(key, "nonce") == 0) {
 822                                 cs->challenges[cs->count]->nonce =
 823                                     strdup(value);
 824                         } else if (strcasecmp(key, "opaque") == 0) {
 825                                 cs->challenges[cs->count]->opaque =
 826                                     strdup(value);
 827                         } else if (strcasecmp(key, "algorithm") == 0) {
 828                                 cs->challenges[cs->count]->algo =
 829                                     strdup(value);
 830                         } else if (strcasecmp(key, "stale") == 0) {
 831                                 cs->challenges[cs->count]->stale =
 832                                     strcasecmp(value, "no");
 833                         } else {
 834                                 /* ignore unknown attributes */
 835                         }
 836
 837                         /* Comma or Next challenge or End */
 838                         lex = http_header_lex(&cp, key);
 839                         /*
 840                          * If we get a word here, this is the beginning of the
 841                          * next challenge. Break the attributes loop
 842                          */
 843                         if (lex == HTTPHL_WORD)
 844                                 break;
 845
 846                         if (lex == HTTPHL_END) {
 847                                 /* End while looking for ',' is normal exit */
 848                                 cs->count++;
 849                                 ret = 0;
 850                                 goto out;
 851                         }
 852                         /* Anything else is an error */
 853                         if (lex != ',')
 854                                 goto out;
 855
 856                 } /* End attributes loop */
 857         } /* End challenge loop */
 858
 859         /*
 860          * Challenges max count exceeded. This really can't happen
 861          * with normal data, something's fishy -> error
 862          */
 863
 864 out:
 865         if (key)
 866                 free(key);
 867         if (value)
 868                 free(value);
 869         if (buf)
 870                 free(buf);
 871         return (ret);
 872 }
 873
 874
 875 /*
 876  * Parse a last-modified header
 877  */
 878 static int
 879 http_parse_mtime(const char *p, time_t *mtime)
 880 {
 881         char locale[64], *r;
 882         struct tm tm;
 883
 884         strlcpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
 885         setlocale(LC_TIME, "C");
 886         r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
 887         /*
 888          * Some proxies use UTC in response, but it should still be
 889          * parsed. RFC2616 states GMT and UTC are exactly equal for HTTP.
 890          */
 891         if (r == NULL)
 892                 r = strptime(p, "%a, %d %b %Y %H:%M:%S UTC", &tm);
 893         /* XXX should add support for date-2 and date-3 */
 894         setlocale(LC_TIME, locale);
 895         if (r == NULL)
 896                 return (-1);
 897         DEBUGF("last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
 898             tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 899             tm.tm_hour, tm.tm_min, tm.tm_sec);
 900         *mtime = timegm(&tm);
 901         return (0);
 902 }
 903
 904 /*
 905  * Parse a content-length header
 906  */
 907 static int
 908 http_parse_length(const char *p, off_t *length)
 909 {
 910         off_t len;
 911
 912         for (len = 0; *p && isdigit((unsigned char)*p); ++p)
 913                 len = len * 10 + (*p - '0');
 914         if (*p)
 915                 return (-1);
 916         DEBUGF("content length: [%lld]\n", (long long)len);
 917         *length = len;
 918         return (0);
 919 }
 920
 921 /*
 922  * Parse a content-range header
 923  */
 924 static int
 925 http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
 926 {
 927         off_t first, last, len;
 928
 929         if (strncasecmp(p, "bytes ", 6) != 0)
 930                 return (-1);
 931         p += 6;
 932         if (*p == '*') {
 933                 first = last = -1;
 934                 ++p;
 935         } else {
 936                 for (first = 0; *p && isdigit((unsigned char)*p); ++p)
 937                         first = first * 10 + *p - '0';
 938                 if (*p != '-')
 939                         return (-1);
 940                 for (last = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
 941                         last = last * 10 + *p - '0';
 942         }
 943         if (first > last || *p != '/')
 944                 return (-1);
 945         for (len = 0, ++p; *p && isdigit((unsigned char)*p); ++p)
 946                 len = len * 10 + *p - '0';
 947         if (*p || len < last - first + 1)
 948                 return (-1);
 949         if (first == -1) {
 950                 DEBUGF("content range: [*/%lld]\n", (long long)len);
 951                 *length = 0;
 952         } else {
 953                 DEBUGF("content range: [%lld-%lld/%lld]\n",
 954                     (long long)first, (long long)last, (long long)len);
 955                 *length = last - first + 1;
 956         }
 957         *offset = first;
 958         *size = len;
 959         return (0);
 960 }
 961
 962
 963 /*****************************************************************************
 964  * Helper functions for authorization
 965  */
 966
 967 /*
 968  * Base64 encoding
 969  */
 970 static char *
 971 http_base64(const char *src)
 972 {
 973         static const char base64[] =
 974             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 975             "abcdefghijklmnopqrstuvwxyz"
 976             "0123456789+/";
 977         char *str, *dst;
 978         size_t l;
 979         int t, r;
 980
 981         l = strlen(src);
 982         if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
 983                 return (NULL);
 984         dst = str;
 985         r = 0;
 986
 987         while (l >= 3) {
 988                 t = (src[0] << 16) | (src[1] << 8) | src[2];
 989                 dst[0] = base64[(t >> 18) & 0x3f];
 990                 dst[1] = base64[(t >> 12) & 0x3f];
 991                 dst[2] = base64[(t >> 6) & 0x3f];
 992                 dst[3] = base64[(t >> 0) & 0x3f];
 993                 src += 3; l -= 3;
 994                 dst += 4; r += 4;
 995         }
 996
 997         switch (l) {
 998         case 2:
 999                 t = (src[0] << 16) | (src[1] << 8);
1000                 dst[0] = base64[(t >> 18) & 0x3f];
1001                 dst[1] = base64[(t >> 12) & 0x3f];
1002                 dst[2] = base64[(t >> 6) & 0x3f];
1003                 dst[3] = '=';
1004                 dst += 4;
1005                 r += 4;
1006                 break;
1007         case 1:
1008                 t = src[0] << 16;
1009                 dst[0] = base64[(t >> 18) & 0x3f];
1010                 dst[1] = base64[(t >> 12) & 0x3f];
1011                 dst[2] = dst[3] = '=';
1012                 dst += 4;
1013                 r += 4;
1014                 break;
1015         case 0:
1016                 break;
1017         }
1018
1019         *dst = 0;
1020         return (str);
1021 }
1022
1023
1024 /*
1025  * Extract authorization parameters from environment value.
1026  * The value is like scheme:realm:user:pass
1027  */
1028 typedef struct {
1029         char    *scheme;
1030         char    *realm;
1031         char    *user;
1032         char    *password;
1033 } http_auth_params_t;
1034
1035 static void
1036 init_http_auth_params(http_auth_params_t *s)
1037 {
1038         s->scheme = s->realm = s->user = s->password = NULL;
1039 }
1040
1041 static void
1042 clean_http_auth_params(http_auth_params_t *s)
1043 {
1044         if (s->scheme)
1045                 free(s->scheme);
1046         if (s->realm)
1047                 free(s->realm);
1048         if (s->user)
1049                 free(s->user);
1050         if (s->password)
1051                 free(s->password);
1052         init_http_auth_params(s);
1053 }
1054
1055 static int
1056 http_authfromenv(const char *p, http_auth_params_t *parms)
1057 {
1058         int ret = -1;
1059         char *v, *ve;
1060         char *str = strdup(p);
1061
1062         if (str == NULL) {
1063                 fetch_syserr();
1064                 return (-1);
1065         }
1066         v = str;
1067
1068         if ((ve = strchr(v, ':')) == NULL)
1069                 goto out;
1070
1071         *ve = 0;
1072         if ((parms->scheme = strdup(v)) == NULL) {
1073                 fetch_syserr();
1074                 goto out;
1075         }
1076         v = ve + 1;
1077
1078         if ((ve = strchr(v, ':')) == NULL)
1079                 goto out;
1080
1081         *ve = 0;
1082         if ((parms->realm = strdup(v)) == NULL) {
1083                 fetch_syserr();
1084                 goto out;
1085         }
1086         v = ve + 1;
1087
1088         if ((ve = strchr(v, ':')) == NULL)
1089                 goto out;
1090
1091         *ve = 0;
1092         if ((parms->user = strdup(v)) == NULL) {
1093                 fetch_syserr();
1094                 goto out;
1095         }
1096         v = ve + 1;
1097
1098
1099         if ((parms->password = strdup(v)) == NULL) {
1100                 fetch_syserr();
1101                 goto out;
1102         }
1103         ret = 0;
1104 out:
1105         if (ret == -1)
1106                 clean_http_auth_params(parms);
1107         if (str)
1108                 free(str);
1109         return (ret);
1110 }
1111
1112
1113 /*
1114  * Digest response: the code to compute the digest is taken from the
1115  * sample implementation in RFC2616
1116  */
1117 #define IN const
1118 #define OUT
1119
1120 #define HASHLEN 16
1121 typedef char HASH[HASHLEN];
1122 #define HASHHEXLEN 32
1123 typedef char HASHHEX[HASHHEXLEN+1];
1124
1125 static const char *hexchars = "0123456789abcdef";
1126 static void
1127 CvtHex(IN HASH Bin, OUT HASHHEX Hex)
1128 {
1129         unsigned short i;
1130         unsigned char j;
1131
1132         for (i = 0; i < HASHLEN; i++) {
1133                 j = (Bin[i] >> 4) & 0xf;
1134                 Hex[i*2] = hexchars[j];
1135                 j = Bin[i] & 0xf;
1136                 Hex[i*2+1] = hexchars[j];
1137         }
1138         Hex[HASHHEXLEN] = '\0';
1139 };
1140
1141 /* calculate H(A1) as per spec */
1142 static void
1143 DigestCalcHA1(
1144         IN char * pszAlg,
1145         IN char * pszUserName,
1146         IN char * pszRealm,
1147         IN char * pszPassword,
1148         IN char * pszNonce,
1149         IN char * pszCNonce,
1150         OUT HASHHEX SessionKey
1151         )
1152 {
1153         MD5_CTX Md5Ctx;
1154         HASH HA1;
1155
1156         MD5Init(&Md5Ctx);
1157         MD5Update(&Md5Ctx, pszUserName, strlen(pszUserName));
1158         MD5Update(&Md5Ctx, ":", 1);
1159         MD5Update(&Md5Ctx, pszRealm, strlen(pszRealm));
1160         MD5Update(&Md5Ctx, ":", 1);
1161         MD5Update(&Md5Ctx, pszPassword, strlen(pszPassword));
1162         MD5Final(HA1, &Md5Ctx);
1163         if (strcasecmp(pszAlg, "md5-sess") == 0) {
1164
1165                 MD5Init(&Md5Ctx);
1166                 MD5Update(&Md5Ctx, HA1, HASHLEN);
1167                 MD5Update(&Md5Ctx, ":", 1);
1168                 MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1169                 MD5Update(&Md5Ctx, ":", 1);
1170                 MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1171                 MD5Final(HA1, &Md5Ctx);
1172         }
1173         CvtHex(HA1, SessionKey);
1174 }
1175
1176 /* calculate request-digest/response-digest as per HTTP Digest spec */
1177 static void
1178 DigestCalcResponse(
1179         IN HASHHEX HA1,           /* H(A1) */
1180         IN char * pszNonce,       /* nonce from server */
1181         IN char * pszNonceCount,  /* 8 hex digits */
1182         IN char * pszCNonce,      /* client nonce */
1183         IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
1184         IN char * pszMethod,      /* method from the request */
1185         IN char * pszDigestUri,   /* requested URL */
1186         IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
1187         OUT HASHHEX Response      /* request-digest or response-digest */
1188         )
1189 {
1190 #if 0
1191         DEBUGF("Calc: HA1[%s] Nonce[%s] qop[%s] method[%s] URI[%s]\n",
1192             HA1, pszNonce, pszQop, pszMethod, pszDigestUri);
1193 #endif
1194         MD5_CTX Md5Ctx;
1195         HASH HA2;
1196         HASH RespHash;
1197         HASHHEX HA2Hex;
1198
1199         // calculate H(A2)
1200         MD5Init(&Md5Ctx);
1201         MD5Update(&Md5Ctx, pszMethod, strlen(pszMethod));
1202         MD5Update(&Md5Ctx, ":", 1);
1203         MD5Update(&Md5Ctx, pszDigestUri, strlen(pszDigestUri));
1204         if (strcasecmp(pszQop, "auth-int") == 0) {
1205                 MD5Update(&Md5Ctx, ":", 1);
1206                 MD5Update(&Md5Ctx, HEntity, HASHHEXLEN);
1207         }
1208         MD5Final(HA2, &Md5Ctx);
1209         CvtHex(HA2, HA2Hex);
1210
1211         // calculate response
1212         MD5Init(&Md5Ctx);
1213         MD5Update(&Md5Ctx, HA1, HASHHEXLEN);
1214         MD5Update(&Md5Ctx, ":", 1);
1215         MD5Update(&Md5Ctx, pszNonce, strlen(pszNonce));
1216         MD5Update(&Md5Ctx, ":", 1);
1217         if (*pszQop) {
1218                 MD5Update(&Md5Ctx, pszNonceCount, strlen(pszNonceCount));
1219                 MD5Update(&Md5Ctx, ":", 1);
1220                 MD5Update(&Md5Ctx, pszCNonce, strlen(pszCNonce));
1221                 MD5Update(&Md5Ctx, ":", 1);
1222                 MD5Update(&Md5Ctx, pszQop, strlen(pszQop));
1223                 MD5Update(&Md5Ctx, ":", 1);
1224         }
1225         MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
1226         MD5Final(RespHash, &Md5Ctx);
1227         CvtHex(RespHash, Response);
1228 }
1229
1230 /*
1231  * Generate/Send a Digest authorization header
1232  * This looks like: [Proxy-]Authorization: credentials
1233  *
1234  *  credentials      = "Digest" digest-response
1235  *  digest-response  = 1#( username | realm | nonce | digest-uri
1236  *                      | response | [ algorithm ] | [cnonce] |
1237  *                      [opaque] | [message-qop] |
1238  *                          [nonce-count]  | [auth-param] )
1239  *  username         = "username" "=" username-value
1240  *  username-value   = quoted-string
1241  *  digest-uri       = "uri" "=" digest-uri-value
1242  *  digest-uri-value = request-uri   ; As specified by HTTP/1.1
1243  *  message-qop      = "qop" "=" qop-value
1244  *  cnonce           = "cnonce" "=" cnonce-value
1245  *  cnonce-value     = nonce-value
1246  *  nonce-count      = "nc" "=" nc-value
1247  *  nc-value         = 8LHEX
1248  *  response         = "response" "=" request-digest
1249  *  request-digest = <"> 32LHEX <">
1250  */
1251 static int
1252 http_digest_auth(conn_t *conn, const char *hdr, http_auth_challenge_t *c,
1253                  http_auth_params_t *parms, struct url *url)
1254 {
1255         int r;
1256         char noncecount[10];
1257         char cnonce[40];
1258         char *options = NULL;
1259
1260         if (!c->realm || !c->nonce) {
1261                 DEBUGF("realm/nonce not set in challenge\n");
1262                 return(-1);
1263         }
1264         if (!c->algo)
1265                 c->algo = strdup("");
1266
1267         if (asprintf(&options, "%s%s%s%s",
1268             *c->algo? ",algorithm=" : "", c->algo,
1269             c->opaque? ",opaque=" : "", c->opaque?c->opaque:"") < 0)
1270                 return (-1);
1271
1272         if (!c->qop) {
1273                 c->qop = strdup("");
1274                 *noncecount = 0;
1275                 *cnonce = 0;
1276         } else {
1277                 c->nc++;
1278                 sprintf(noncecount, "%08x", c->nc);
1279                 /* We don't try very hard with the cnonce ... */
1280                 sprintf(cnonce, "%x%lx", getpid(), (unsigned long)time(0));
1281         }
1282
1283         HASHHEX HA1;
1284         DigestCalcHA1(c->algo, parms->user, c->realm,
1285                       parms->password, c->nonce, cnonce, HA1);
1286         DEBUGF("HA1: [%s]\n", HA1);
1287         HASHHEX digest;
1288         DigestCalcResponse(HA1, c->nonce, noncecount, cnonce, c->qop,
1289                            "GET", url->doc, "", digest);
1290
1291         if (c->qop[0]) {
1292                 r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1293                              "nonce=\"%s\",uri=\"%s\",response=\"%s\","
1294                              "qop=\"auth\", cnonce=\"%s\", nc=%s%s",
1295                              hdr, parms->user, c->realm,
1296                              c->nonce, url->doc, digest,
1297                              cnonce, noncecount, options);
1298         } else {
1299                 r = http_cmd(conn, "%s: Digest username=\"%s\",realm=\"%s\","
1300                              "nonce=\"%s\",uri=\"%s\",response=\"%s\"%s",
1301                              hdr, parms->user, c->realm,
1302                              c->nonce, url->doc, digest, options);
1303         }
1304         if (options)
1305                 free(options);
1306         return (r);
1307 }
1308
1309 /*
1310  * Encode username and password
1311  */
1312 static int
1313 http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
1314 {
1315         char *upw, *auth;
1316         int r;
1317
1318         DEBUGF("basic: usr: [%s]\n", usr);
1319         DEBUGF("basic: pwd: [%s]\n", pwd);
1320         if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
1321                 return (-1);
1322         auth = http_base64(upw);
1323         free(upw);
1324         if (auth == NULL)
1325                 return (-1);
1326         r = http_cmd(conn, "%s: Basic %s", hdr, auth);
1327         free(auth);
1328         return (r);
1329 }
1330
1331 /*
1332  * Chose the challenge to answer and call the appropriate routine to
1333  * produce the header.
1334  */
1335 static int
1336 http_authorize(conn_t *conn, const char *hdr, http_auth_challenges_t *cs,
1337                http_auth_params_t *parms, struct url *url)
1338 {
1339         http_auth_challenge_t *digest = NULL;
1340         int i;
1341
1342         /* If user or pass are null we're not happy */
1343         if (!parms->user || !parms->password) {
1344                 DEBUGF("NULL usr or pass\n");
1345                 return (-1);
1346         }
1347
1348         /* Look for a Digest */
1349         for (i = 0; i < cs->count; i++) {
1350                 if (cs->challenges[i]->scheme == HTTPAS_DIGEST)
1351                         digest = cs->challenges[i];
1352         }
1353
1354         /* Error if "Digest" was specified and there is no Digest challenge */
1355         if (!digest &&
1356             (parms->scheme && strcasecmp(parms->scheme, "digest") == 0)) {
1357                 DEBUGF("Digest auth in env, not supported by peer\n");
1358                 return (-1);
1359         }
1360         /*
1361          * If "basic" was specified in the environment, or there is no Digest
1362          * challenge, do the basic thing. Don't need a challenge for this,
1363          * so no need to check basic!=NULL
1364          */
1365         if (!digest ||
1366             (parms->scheme && strcasecmp(parms->scheme, "basic") == 0))
1367                 return (http_basic_auth(conn,hdr,parms->user,parms->password));
1368
1369         /* Else, prefer digest. We just checked that it's not NULL */
1370         return (http_digest_auth(conn, hdr, digest, parms, url));
1371 }
1372
1373 /*****************************************************************************
1374  * Helper functions for connecting to a server or proxy
1375  */
1376
1377 /*
1378  * Connect to the correct HTTP server or proxy.
1379  */
1380 static conn_t *
1381 http_connect(struct url *URL, struct url *purl, const char *flags)
1382 {
1383         struct url *curl;
1384         conn_t *conn;
1385         hdr_t h;
1386         http_headerbuf_t headerbuf;
1387         const char *p;
1388         int verbose;
1389         int af, val;
1390         int serrno;
1391         bool isproxyauth = false;
1392         http_auth_challenges_t proxy_challenges;
1393
1394 #ifdef INET6
1395         af = AF_UNSPEC;
1396 #else
1397         af = AF_INET;
1398 #endif
1399
1400         verbose = CHECK_FLAG('v');
1401         if (CHECK_FLAG('4'))
1402                 af = AF_INET;
1403 #ifdef INET6
1404         else if (CHECK_FLAG('6'))
1405                 af = AF_INET6;
1406 #endif
1407
1408         curl = (purl != NULL) ? purl : URL;
1409
1410 retry:
1411         if ((conn = fetch_connect(curl->host, curl->port, af, verbose)) == NULL)
1412                 /* fetch_connect() has already set an error code */
1413                 return (NULL);
1414         init_http_headerbuf(&headerbuf);
1415         if (strcmp(URL->scheme, SCHEME_HTTPS) == 0 && purl) {
1416                 init_http_auth_challenges(&proxy_challenges);
1417                 http_cmd(conn, "CONNECT %s:%d HTTP/1.1", URL->host, URL->port);
1418                 http_cmd(conn, "Host: %s:%d", URL->host, URL->port);
1419                 if (isproxyauth) {
1420                         http_auth_params_t aparams;
1421                         init_http_auth_params(&aparams);
1422                         if (*purl->user || *purl->pwd) {
1423                                 aparams.user = strdup(purl->user);
1424                                 aparams.password = strdup(purl->pwd);
1425                         } else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1426                                     *p != '\0') {
1427                                 if (http_authfromenv(p, &aparams) < 0) {
1428                                         http_seterr(HTTP_NEED_PROXY_AUTH);
1429                                         fetch_syserr();
1430                                         goto ouch;
1431                                 }
1432                         } else if (fetch_netrc_auth(purl) == 0) {
1433                                 aparams.user = strdup(purl->user);
1434                                 aparams.password = strdup(purl->pwd);
1435                         } else {
1436                                 /*
1437                                  * No auth information found in system - exiting
1438                                  * with warning.
1439                                  */
1440                                 warnx("Missing username and/or password set");
1441                                 fetch_syserr();
1442                                 goto ouch;
1443                         }
1444                         http_authorize(conn, "Proxy-Authorization",
1445                             &proxy_challenges, &aparams, purl);
1446                         clean_http_auth_params(&aparams);
1447                 }
1448                 http_cmd(conn, "");
1449                 /* Get reply from CONNECT Tunnel attempt */
1450                 int httpreply = http_get_reply(conn);
1451                 if (httpreply != HTTP_OK) {
1452                         http_seterr(httpreply);
1453                         /* If the error is a 407/HTTP_NEED_PROXY_AUTH */
1454                         if (httpreply == HTTP_NEED_PROXY_AUTH &&
1455                             ! isproxyauth) {
1456                                 /* Try again with authentication. */
1457                                 clean_http_headerbuf(&headerbuf);
1458                                 fetch_close(conn);
1459                                 isproxyauth = true;
1460                                 goto retry;
1461                         }
1462                         goto ouch;
1463                 }
1464                 /* Read and discard the rest of the proxy response */
1465                 if (fetch_getln(conn) < 0) {
1466                         fetch_syserr();
1467                         goto ouch;
1468                 }
1469                 do {
1470                         switch ((h = http_next_header(conn, &headerbuf, &p))) {
1471                         case hdr_syserror:
1472                                 fetch_syserr();
1473                                 goto ouch;
1474                         case hdr_error:
1475                                 http_seterr(HTTP_PROTOCOL_ERROR);
1476                                 goto ouch;
1477                         default:
1478                                 /* ignore */ ;
1479                         }
1480                 } while (h > hdr_end);
1481         }
1482         if (strcmp(URL->scheme, SCHEME_HTTPS) == 0 &&
1483             fetch_ssl(conn, URL, verbose) == -1) {
1484                 /* grrr */
1485                 errno = EAUTH;
1486                 fetch_syserr();
1487                 goto ouch;
1488         }
1489
1490         val = 1;
1491         setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
1492
1493         clean_http_headerbuf(&headerbuf);
1494         return (conn);
1495 ouch:
1496         serrno = errno;
1497         clean_http_headerbuf(&headerbuf);
1498         fetch_close(conn);
1499         errno = serrno;
1500         return (NULL);
1501 }
1502
1503 static struct url *
1504 http_get_proxy(struct url * url, const char *flags)
1505 {
1506         struct url *purl;
1507         char *p;
1508
1509         if (flags != NULL && strchr(flags, 'd') != NULL)
1510                 return (NULL);
1511         if (fetch_no_proxy_match(url->host))
1512                 return (NULL);
1513         if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1514             *p && (purl = fetchParseURL(p))) {
1515                 if (!*purl->scheme)
1516                         strcpy(purl->scheme, SCHEME_HTTP);
1517                 if (!purl->port)
1518                         purl->port = fetch_default_proxy_port(purl->scheme);
1519                 if (strcmp(purl->scheme, SCHEME_HTTP) == 0)
1520                         return (purl);
1521                 fetchFreeURL(purl);
1522         }
1523         return (NULL);
1524 }
1525
1526 static void
1527 http_print_html(FILE *out, FILE *in)
1528 {
1529         size_t len;
1530         char *line, *p, *q;
1531         int comment, tag;
1532
1533         comment = tag = 0;
1534         while ((line = fgetln(in, &len)) != NULL) {
1535                 while (len && isspace((unsigned char)line[len - 1]))
1536                         --len;
1537                 for (p = q = line; q < line + len; ++q) {
1538                         if (comment && *q == '-') {
1539                                 if (q + 2 < line + len &&
1540                                     strcmp(q, "-->") == 0) {
1541                                         tag = comment = 0;
1542                                         q += 2;
1543                                 }
1544                         } else if (tag && !comment && *q == '>') {
1545                                 p = q + 1;
1546                                 tag = 0;
1547                         } else if (!tag && *q == '<') {
1548                                 if (q > p)
1549                                         fwrite(p, q - p, 1, out);
1550                                 tag = 1;
1551                                 if (q + 3 < line + len &&
1552                                     strcmp(q, "<!--") == 0) {
1553                                         comment = 1;
1554                                         q += 3;
1555                                 }
1556                         }
1557                 }
1558                 if (!tag && q > p)
1559                         fwrite(p, q - p, 1, out);
1560                 fputc('\n', out);
1561         }
1562 }
1563
1564
1565 /*****************************************************************************
1566  * Core
1567  */
1568
1569 FILE *
1570 http_request(struct url *URL, const char *op, struct url_stat *us,
1571         struct url *purl, const char *flags)
1572 {
1573
1574         return (http_request_body(URL, op, us, purl, flags, NULL, NULL));
1575 }
1576
1577 /*
1578  * Send a request and process the reply
1579  *
1580  * XXX This function is way too long, the do..while loop should be split
1581  * XXX off into a separate function.
1582  */
1583 FILE *
1584 http_request_body(struct url *URL, const char *op, struct url_stat *us,
1585         struct url *purl, const char *flags, const char *content_type,
1586         const char *body)
1587 {
1588         char timebuf[80];
1589         char hbuf[MAXHOSTNAMELEN + 7], *host;
1590         conn_t *conn;
1591         struct url *url, *new;
1592         int chunked, direct, ims, noredirect, verbose;
1593         int e, i, n, val;
1594         off_t offset, clength, length, size;
1595         time_t mtime;
1596         const char *p;
1597         FILE *f;
1598         hdr_t h;
1599         struct tm *timestruct;
1600         http_headerbuf_t headerbuf;
1601         http_auth_challenges_t server_challenges;
1602         http_auth_challenges_t proxy_challenges;
1603         size_t body_len;
1604
1605         /* The following calls don't allocate anything */
1606         init_http_headerbuf(&headerbuf);
1607         init_http_auth_challenges(&server_challenges);
1608         init_http_auth_challenges(&proxy_challenges);
1609
1610         direct = CHECK_FLAG('d');
1611         noredirect = CHECK_FLAG('A');
1612         verbose = CHECK_FLAG('v');
1613         ims = CHECK_FLAG('i');
1614
1615         if (direct && purl) {
1616                 fetchFreeURL(purl);
1617                 purl = NULL;
1618         }
1619
1620         /* try the provided URL first */
1621         url = URL;
1622
1623         n = MAX_REDIRECT;
1624         i = 0;
1625
1626         e = HTTP_PROTOCOL_ERROR;
1627         do {
1628                 new = NULL;
1629                 chunked = 0;
1630                 offset = 0;
1631                 clength = -1;
1632                 length = -1;
1633                 size = -1;
1634                 mtime = 0;
1635
1636                 /* check port */
1637                 if (!url->port)
1638                         url->port = fetch_default_port(url->scheme);
1639
1640                 /* were we redirected to an FTP URL? */
1641                 if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
1642                         if (strcmp(op, "GET") == 0)
1643                                 return (ftp_request(url, "RETR", us, purl, flags));
1644                         else if (strcmp(op, "HEAD") == 0)
1645                                 return (ftp_request(url, "STAT", us, purl, flags));
1646                 }
1647
1648                 /* connect to server or proxy */
1649                 if ((conn = http_connect(url, purl, flags)) == NULL)
1650                         goto ouch;
1651
1652                 /* append port number only if necessary */
1653                 host = url->host;
1654                 if (url->port != fetch_default_port(url->scheme)) {
1655                         snprintf(hbuf, sizeof(hbuf), "%s:%d", host, url->port);
1656                         host = hbuf;
1657                 }
1658
1659                 /* send request */
1660                 if (verbose)
1661                         fetch_info("requesting %s://%s%s",
1662                             url->scheme, host, url->doc);
1663                 if (purl && strcmp(URL->scheme, SCHEME_HTTPS) != 0) {
1664                         http_cmd(conn, "%s %s://%s%s HTTP/1.1",
1665                             op, url->scheme, host, url->doc);
1666                 } else {
1667                         http_cmd(conn, "%s %s HTTP/1.1",
1668                             op, url->doc);
1669                 }
1670
1671                 if (ims && url->ims_time) {
1672                         timestruct = gmtime((time_t *)&url->ims_time);
1673                         (void)strftime(timebuf, 80, "%a, %d %b %Y %T GMT",
1674                             timestruct);
1675                         if (verbose)
1676                                 fetch_info("If-Modified-Since: %s", timebuf);
1677                         http_cmd(conn, "If-Modified-Since: %s", timebuf);
1678                 }
1679                 /* virtual host */
1680                 http_cmd(conn, "Host: %s", host);
1681
1682                 /*
1683                  * Proxy authorization: we only send auth after we received
1684                  * a 407 error. We do not first try basic anyway (changed
1685                  * when support was added for digest-auth)
1686                  */
1687                 if (purl && proxy_challenges.valid) {
1688                         http_auth_params_t aparams;
1689                         init_http_auth_params(&aparams);
1690                         if (*purl->user || *purl->pwd) {
1691                                 aparams.user = strdup(purl->user);
1692                                 aparams.password = strdup(purl->pwd);
1693                         } else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL &&
1694                                    *p != '\0') {
1695                                 if (http_authfromenv(p, &aparams) < 0) {
1696                                         http_seterr(HTTP_NEED_PROXY_AUTH);
1697                                         goto ouch;
1698                                 }
1699                         } else if (fetch_netrc_auth(purl) == 0) {
1700                                 aparams.user = strdup(purl->user);
1701                                 aparams.password = strdup(purl->pwd);
1702                         }
1703                         http_authorize(conn, "Proxy-Authorization",
1704                                        &proxy_challenges, &aparams, url);
1705                         clean_http_auth_params(&aparams);
1706                 }
1707
1708                 /*
1709                  * Server authorization: we never send "a priori"
1710                  * Basic auth, which used to be done if user/pass were
1711                  * set in the url. This would be weird because we'd send the
1712                  * password in the clear even if Digest is finally to be
1713                  * used (it would have made more sense for the
1714                  * pre-digest version to do this when Basic was specified
1715                  * in the environment)
1716                  */
1717                 if (server_challenges.valid) {
1718                         http_auth_params_t aparams;
1719                         init_http_auth_params(&aparams);
1720                         if (*url->user || *url->pwd) {
1721                                 aparams.user = strdup(url->user);
1722                                 aparams.password = strdup(url->pwd);
1723                         } else if ((p = getenv("HTTP_AUTH")) != NULL &&
1724                                    *p != '\0') {
1725                                 if (http_authfromenv(p, &aparams) < 0) {
1726                                         http_seterr(HTTP_NEED_AUTH);
1727                                         goto ouch;
1728                                 }
1729                         } else if (fetch_netrc_auth(url) == 0) {
1730                                 aparams.user = strdup(url->user);
1731                                 aparams.password = strdup(url->pwd);
1732                         } else if (fetchAuthMethod &&
1733                                    fetchAuthMethod(url) == 0) {
1734                                 aparams.user = strdup(url->user);
1735                                 aparams.password = strdup(url->pwd);
1736                         } else {
1737                                 http_seterr(HTTP_NEED_AUTH);
1738                                 goto ouch;
1739                         }
1740                         http_authorize(conn, "Authorization",
1741                                        &server_challenges, &aparams, url);
1742                         clean_http_auth_params(&aparams);
1743                 }
1744
1745                 /* other headers */
1746                 if ((p = getenv("HTTP_ACCEPT")) != NULL) {
1747                         if (*p != '\0')
1748                                 http_cmd(conn, "Accept: %s", p);
1749                 } else {
1750                         http_cmd(conn, "Accept: */*");
1751                 }
1752                 if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
1753                         if (strcasecmp(p, "auto") == 0)
1754                                 http_cmd(conn, "Referer: %s://%s%s",
1755                                     url->scheme, host, url->doc);
1756                         else
1757                                 http_cmd(conn, "Referer: %s", p);
1758                 }
1759                 if ((p = getenv("HTTP_USER_AGENT")) != NULL) {
1760                         /* no User-Agent if defined but empty */
1761                         if  (*p != '\0')
1762                                 http_cmd(conn, "User-Agent: %s", p);
1763                 } else {
1764                         /* default User-Agent */
1765                         http_cmd(conn, "User-Agent: %s " _LIBFETCH_VER,
1766                             getprogname());
1767                 }
1768                 if (url->offset > 0)
1769                         http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
1770                 http_cmd(conn, "Connection: close");
1771
1772                 if (body) {
1773                         body_len = strlen(body);
1774                         http_cmd(conn, "Content-Length: %zu", body_len);
1775                         if (content_type != NULL)
1776                                 http_cmd(conn, "Content-Type: %s", content_type);
1777                 }
1778
1779                 http_cmd(conn, "");
1780
1781                 if (body)
1782                         fetch_write(conn, body, body_len);
1783
1784                 /*
1785                  * Force the queued request to be dispatched.  Normally, one
1786                  * would do this with shutdown(2) but squid proxies can be
1787                  * configured to disallow such half-closed connections.  To
1788                  * be compatible with such configurations, fiddle with socket
1789                  * options to force the pending data to be written.
1790                  */
1791                 val = 0;
1792                 setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
1793                            sizeof(val));
1794                 val = 1;
1795                 setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
1796                            sizeof(val));
1797
1798                 /* get reply */
1799                 switch (http_get_reply(conn)) {
1800                 case HTTP_OK:
1801                 case HTTP_PARTIAL:
1802                 case HTTP_NOT_MODIFIED:
1803                         /* fine */
1804                         break;
1805                 case HTTP_MOVED_PERM:
1806                 case HTTP_MOVED_TEMP:
1807                 case HTTP_TEMP_REDIRECT:
1808                 case HTTP_PERM_REDIRECT:
1809                 case HTTP_SEE_OTHER:
1810                 case HTTP_USE_PROXY:
1811                         /*
1812                          * Not so fine, but we still have to read the
1813                          * headers to get the new location.
1814                          */
1815                         break;
1816                 case HTTP_NEED_AUTH:
1817                         if (server_challenges.valid) {
1818                                 /*
1819                                  * We already sent out authorization code,
1820                                  * so there's nothing more we can do.
1821                                  */
1822                                 http_seterr(conn->err);
1823                                 goto ouch;
1824                         }
1825                         /* try again, but send the password this time */
1826                         if (verbose)
1827                                 fetch_info("server requires authorization");
1828                         break;
1829                 case HTTP_NEED_PROXY_AUTH:
1830                         if (proxy_challenges.valid) {
1831                                 /*
1832                                  * We already sent our proxy
1833                                  * authorization code, so there's
1834                                  * nothing more we can do. */
1835                                 http_seterr(conn->err);
1836                                 goto ouch;
1837                         }
1838                         /* try again, but send the password this time */
1839                         if (verbose)
1840                                 fetch_info("proxy requires authorization");
1841                         break;
1842                 case HTTP_BAD_RANGE:
1843                         /*
1844                          * This can happen if we ask for 0 bytes because
1845                          * we already have the whole file.  Consider this
1846                          * a success for now, and check sizes later.
1847                          */
1848                         break;
1849                 case HTTP_PROTOCOL_ERROR:
1850                         /* fall through */
1851                 case -1:
1852                         fetch_syserr();
1853                         goto ouch;
1854                 default:
1855                         http_seterr(conn->err);
1856                         if (!verbose)
1857                                 goto ouch;
1858                         /* fall through so we can get the full error message */
1859                 }
1860
1861                 /* get headers. http_next_header expects one line readahead */
1862                 if (fetch_getln(conn) == -1) {
1863                         fetch_syserr();
1864                         goto ouch;
1865                 }
1866                 do {
1867                         switch ((h = http_next_header(conn, &headerbuf, &p))) {
1868                         case hdr_syserror:
1869                                 fetch_syserr();
1870                                 goto ouch;
1871                         case hdr_error:
1872                                 http_seterr(HTTP_PROTOCOL_ERROR);
1873                                 goto ouch;
1874                         case hdr_content_length:
1875                                 http_parse_length(p, &clength);
1876                                 break;
1877                         case hdr_content_range:
1878                                 http_parse_range(p, &offset, &length, &size);
1879                                 break;
1880                         case hdr_last_modified:
1881                                 http_parse_mtime(p, &mtime);
1882                                 break;
1883                         case hdr_location:
1884                                 if (!HTTP_REDIRECT(conn->err))
1885                                         break;
1886                                 /*
1887                                  * if the A flag is set, we don't follow
1888                                  * temporary redirects.
1889                                  */
1890                                 if (noredirect &&
1891                                     conn->err != HTTP_MOVED_PERM &&
1892                                     conn->err != HTTP_PERM_REDIRECT &&
1893                                     conn->err != HTTP_USE_PROXY) {
1894                                         n = 1;
1895                                         break;
1896                                 }
1897                                 if (new)
1898                                         free(new);
1899                                 if (verbose)
1900                                         fetch_info("%d redirect to %s",
1901                                             conn->err, p);
1902                                 if (*p == '/')
1903                                         /* absolute path */
1904                                         new = fetchMakeURL(url->scheme, url->host,
1905                                             url->port, p, url->user, url->pwd);
1906                                 else
1907                                         new = fetchParseURL(p);
1908                                 if (new == NULL) {
1909                                         /* XXX should set an error code */
1910                                         DEBUGF("failed to parse new URL\n");
1911                                         goto ouch;
1912                                 }
1913
1914                                 /* Only copy credentials if the host matches */
1915                                 if (strcmp(new->host, url->host) == 0 &&
1916                                     !*new->user && !*new->pwd) {
1917                                         strcpy(new->user, url->user);
1918                                         strcpy(new->pwd, url->pwd);
1919                                 }
1920                                 new->offset = url->offset;
1921                                 new->length = url->length;
1922                                 new->ims_time = url->ims_time;
1923                                 break;
1924                         case hdr_transfer_encoding:
1925                                 /* XXX weak test*/
1926                                 chunked = (strcasecmp(p, "chunked") == 0);
1927                                 break;
1928                         case hdr_www_authenticate:
1929                                 if (conn->err != HTTP_NEED_AUTH)
1930                                         break;
1931                                 if (http_parse_authenticate(p, &server_challenges) == 0)
1932                                         ++n;
1933                                 break;
1934                         case hdr_proxy_authenticate:
1935                                 if (conn->err != HTTP_NEED_PROXY_AUTH)
1936                                         break;
1937                                 if (http_parse_authenticate(p, &proxy_challenges) == 0)
1938                                         ++n;
1939                                 break;
1940                         case hdr_end:
1941                                 /* fall through */
1942                         case hdr_unknown:
1943                                 /* ignore */
1944                                 break;
1945                         }
1946                 } while (h > hdr_end);
1947
1948                 /* we need to provide authentication */
1949                 if (conn->err == HTTP_NEED_AUTH ||
1950                     conn->err == HTTP_NEED_PROXY_AUTH) {
1951                         e = conn->err;
1952                         if ((conn->err == HTTP_NEED_AUTH &&
1953                              !server_challenges.valid) ||
1954                             (conn->err == HTTP_NEED_PROXY_AUTH &&
1955                              !proxy_challenges.valid)) {
1956                                 /* 401/7 but no www/proxy-authenticate ?? */
1957                                 DEBUGF("%03d without auth header\n", conn->err);
1958                                 goto ouch;
1959                         }
1960                         fetch_close(conn);
1961                         conn = NULL;
1962                         continue;
1963                 }
1964
1965                 /* requested range not satisfiable */
1966                 if (conn->err == HTTP_BAD_RANGE) {
1967                         if (url->offset > 0 && url->length == 0) {
1968                                 /* asked for 0 bytes; fake it */
1969                                 offset = url->offset;
1970                                 clength = -1;
1971                                 conn->err = HTTP_OK;
1972                                 break;
1973                         } else {
1974                                 http_seterr(conn->err);
1975                                 goto ouch;
1976                         }
1977                 }
1978
1979                 /* we have a hit or an error */
1980                 if (conn->err == HTTP_OK
1981                     || conn->err == HTTP_NOT_MODIFIED
1982                     || conn->err == HTTP_PARTIAL
1983                     || HTTP_ERROR(conn->err))
1984                         break;
1985
1986                 /* all other cases: we got a redirect */
1987                 e = conn->err;
1988                 clean_http_auth_challenges(&server_challenges);
1989                 fetch_close(conn);
1990                 conn = NULL;
1991                 if (!new) {
1992                         DEBUGF("redirect with no new location\n");
1993                         break;
1994                 }
1995                 if (url != URL)
1996                         fetchFreeURL(url);
1997                 url = new;
1998         } while (++i < n);
1999
2000         /* we failed, or ran out of retries */
2001         if (conn == NULL) {
2002                 http_seterr(e);
2003                 goto ouch;
2004         }
2005
2006         DEBUGF("offset %lld, length %lld, size %lld, clength %lld\n",
2007             (long long)offset, (long long)length,
2008             (long long)size, (long long)clength);
2009
2010         if (conn->err == HTTP_NOT_MODIFIED) {
2011                 http_seterr(HTTP_NOT_MODIFIED);
2012                 return (NULL);
2013         }
2014
2015         /* check for inconsistencies */
2016         if (clength != -1 && length != -1 && clength != length) {
2017                 http_seterr(HTTP_PROTOCOL_ERROR);
2018                 goto ouch;
2019         }
2020         if (clength == -1)
2021                 clength = length;
2022         if (clength != -1)
2023                 length = offset + clength;
2024         if (length != -1 && size != -1 && length != size) {
2025                 http_seterr(HTTP_PROTOCOL_ERROR);
2026                 goto ouch;
2027         }
2028         if (size == -1)
2029                 size = length;
2030
2031         /* fill in stats */
2032         if (us) {
2033                 us->size = size;
2034                 us->atime = us->mtime = mtime;
2035         }
2036
2037         /* too far? */
2038         if (URL->offset > 0 && offset > URL->offset) {
2039                 http_seterr(HTTP_PROTOCOL_ERROR);
2040                 goto ouch;
2041         }
2042
2043         /* report back real offset and size */
2044         URL->offset = offset;
2045         URL->length = clength;
2046
2047         /* wrap it up in a FILE */
2048         if ((f = http_funopen(conn, chunked)) == NULL) {
2049                 fetch_syserr();
2050                 goto ouch;
2051         }
2052
2053         if (url != URL)
2054                 fetchFreeURL(url);
2055         if (purl)
2056                 fetchFreeURL(purl);
2057
2058         if (HTTP_ERROR(conn->err)) {
2059                 http_print_html(stderr, f);
2060                 fclose(f);
2061                 f = NULL;
2062         }
2063         clean_http_headerbuf(&headerbuf);
2064         clean_http_auth_challenges(&server_challenges);
2065         clean_http_auth_challenges(&proxy_challenges);
2066         return (f);
2067
2068 ouch:
2069         if (url != URL)
2070                 fetchFreeURL(url);
2071         if (purl)
2072                 fetchFreeURL(purl);
2073         if (conn != NULL)
2074                 fetch_close(conn);
2075         clean_http_headerbuf(&headerbuf);
2076         clean_http_auth_challenges(&server_challenges);
2077         clean_http_auth_challenges(&proxy_challenges);
2078         return (NULL);
2079 }
2080
2081
2082 /*****************************************************************************
2083  * Entry points
2084  */
2085
2086 /*
2087  * Retrieve and stat a file by HTTP
2088  */
2089 FILE *
2090 fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
2091 {
2092         return (http_request(URL, "GET", us, http_get_proxy(URL, flags), flags));
2093 }
2094
2095 /*
2096  * Retrieve a file by HTTP
2097  */
2098 FILE *
2099 fetchGetHTTP(struct url *URL, const char *flags)
2100 {
2101         return (fetchXGetHTTP(URL, NULL, flags));
2102 }
2103
2104 /*
2105  * Store a file by HTTP
2106  */
2107 FILE *
2108 fetchPutHTTP(struct url *URL __unused, const char *flags __unused)
2109 {
2110         warnx("fetchPutHTTP(): not implemented");
2111         return (NULL);
2112 }
2113
2114 /*
2115  * Get an HTTP document's metadata
2116  */
2117 int
2118 fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
2119 {
2120         FILE *f;
2121
2122         f = http_request(URL, "HEAD", us, http_get_proxy(URL, flags), flags);
2123         if (f == NULL)
2124                 return (-1);
2125         fclose(f);
2126         return (0);
2127 }
2128
2129 /*
2130  * List a directory
2131  */
2132 struct url_ent *
2133 fetchListHTTP(struct url *url __unused, const char *flags __unused)
2134 {
2135         warnx("fetchListHTTP(): not implemented");
2136         return (NULL);
2137 }
2138
2139 /*
2140  * Arbitrary HTTP verb and content requests
2141  */
2142 FILE *
2143 fetchReqHTTP(struct url *URL, const char *method, const char *flags,
2144         const char *content_type, const char *body)
2145 {
2146
2147         return (http_request_body(URL, method, NULL, http_get_proxy(URL, flags),
2148             flags, content_type, body));
2149 }