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