http.c

   1 /*
   2  * OpenConnect (SSL + DTLS) VPN client
   3  *
   4  * Copyright © 2008 Intel Corporation.
   5  * Copyright © 2008 Nick Andrew <nick@nick-andrew.net>
   6  *
   7  * Author: David Woodhouse <dwmw2@infradead.org>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * version 2.1, as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to:
  20  *
  21  *   Free Software Foundation, Inc.
  22  *   51 Franklin Street, Fifth Floor,
  23  *   Boston, MA 02110-1301 USA
  24  */
  25
  26 #define _GNU_SOURCE
  27 #include <netdb.h>
  28 #include <unistd.h>
  29 #include <fcntl.h>
  30 #include <time.h>
  31 #include <string.h>
  32 #include <ctype.h>
  33 #include <pwd.h>
  34 #include <sys/stat.h>
  35 #include <sys/types.h>
  36
  37 #include <openssl/ssl.h>
  38 #include <openssl/err.h>
  39 #include <openssl/engine.h>
  40
  41 #include "openconnect.h"
  42
  43 #define MAX_BUF_LEN 131072
  44 /*
  45  * We didn't really want to have to do this for ourselves -- one might have
  46  * thought that it would be available in a library somewhere. But neither
  47  * cURL nor Neon have reliable cross-platform ways of either using a cert
  48  * from the TPM, or just reading from / writing to a transport which is
  49  * provided by their caller.
  50  */
  51
  52 int http_add_cookie(struct openconnect_info *vpninfo, const char *option, const char *value)
  53 {
  54         struct vpn_option *new, **this;
  55
  56         if (*value) {
  57                 new = malloc(sizeof(*new));
  58                 if (!new) {
  59                         vpninfo->progress(vpninfo, PRG_ERR, "No memory for allocating cookies\n");
  60                         return -ENOMEM;
  61                 }
  62                 new->next = NULL;
  63                 new->option = strdup(option);
  64                 new->value = strdup(value);
  65                 if (!new->option || !new->value) {
  66                         free(new->option);
  67                         free(new->value);
  68                         free(new);
  69                         return -ENOMEM;
  70                 }
  71         } else {
  72                 /* Kill cookie; don't replace it */
  73                 new = NULL;
  74         }
  75         for (this = &vpninfo->cookies; *this; this = &(*this)->next) {
  76                 if (!strcmp(option, (*this)->option)) {
  77                         /* Replace existing cookie */
  78                         if (new)
  79                                 new->next = (*this)->next;
  80                         else
  81                                 new = (*this)->next;
  82
  83                         free((*this)->option);
  84                         free((*this)->value);
  85                         free(*this);
  86                         *this = new;
  87                         break;
  88                 }
  89         }
  90         if (new && !*this) {
  91                 *this = new;
  92                 new->next = NULL;
  93         }
  94         return 0;
  95 }
  96
  97 static int process_http_response(struct openconnect_info *vpninfo, int *result,
  98                                  int (*header_cb)(struct openconnect_info *, char *, char *),
  99                                  char *body, int buf_len)
 100 {
 101         char buf[MAX_BUF_LEN];
 102         int bodylen = 0;
 103         int done = 0;
 104         int http10 = 0, closeconn = 0;
 105         int i;
 106
 107         if (openconnect_SSL_gets(vpninfo->https_ssl, buf, sizeof(buf)) < 0) {
 108                 vpninfo->progress(vpninfo, PRG_ERR, "Error fetching HTTPS response\n");
 109                 return -EINVAL;
 110         }
 111
 112  cont:
 113         if (!strncmp(buf, "HTTP/1.0 ", 9)) {
 114                 http10 = 1;
 115                 closeconn = 1;
 116         }
 117
 118         if ((!http10 && strncmp(buf, "HTTP/1.1 ", 9)) || !(*result = atoi(buf+9))) {
 119                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to parse HTTP response '%s'\n", buf);
 120                 return -EINVAL;
 121         }
 122
 123         vpninfo->progress(vpninfo, PRG_TRACE, "Got HTTP response: %s\n", buf);
 124
 125         /* Eat headers... */
 126         while ((i = openconnect_SSL_gets(vpninfo->https_ssl, buf, sizeof(buf)))) {
 127                 char *colon;
 128
 129                 vpninfo->progress(vpninfo, PRG_TRACE, "%s\n", buf);
 130
 131                 if (i < 0) {
 132                         vpninfo->progress(vpninfo, PRG_ERR, "Error processing HTTP response\n");
 133                         return -EINVAL;
 134                 }
 135                 colon = strchr(buf, ':');
 136                 if (!colon) {
 137                         vpninfo->progress(vpninfo, PRG_ERR, "Ignoring unknown HTTP response line '%s'\n", buf);
 138                         continue;
 139                 }
 140                 *(colon++) = 0;
 141                 if (*colon == ' ')
 142                         colon++;
 143
 144                 if (!strcmp(buf, "Connection") && !strcmp(colon, "Close"))
 145                         closeconn = 1;
 146
 147                 if (!strcmp(buf, "Location")) {
 148                         vpninfo->redirect_url = strdup(colon);
 149                         if (!vpninfo->redirect_url)
 150                                 return -ENOMEM;
 151                 }
 152                 if (!strcmp(buf, "Content-Length")) {
 153                         bodylen = atoi(colon);
 154                         if (bodylen < 0 || bodylen > buf_len) {
 155                                 vpninfo->progress(vpninfo, PRG_ERR, "Response body too large for buffer (%d > %d)\n",
 156                                         bodylen, buf_len);
 157                                 return -EINVAL;
 158                         }
 159                 }
 160                 if (!strcmp(buf, "Set-Cookie")) {
 161                         char *semicolon = strchr(colon, ';');
 162                         char *equals = strchr(colon, '=');
 163                         int ret;
 164
 165                         if (semicolon)
 166                                 *semicolon = 0;
 167
 168                         if (!equals) {
 169                                 vpninfo->progress(vpninfo, PRG_ERR, "Invalid cookie offered: %s\n", buf);
 170                                 return -EINVAL;
 171                         }
 172                         *(equals++) = 0;
 173
 174                         ret = http_add_cookie(vpninfo, colon, equals);
 175                         if (ret)
 176                                 return ret;
 177                 }
 178                 if (!strcmp(buf, "Transfer-Encoding")) {
 179                         if (!strcmp(colon, "chunked"))
 180                                 bodylen = -1;
 181                         else {
 182                                 vpninfo->progress(vpninfo, PRG_ERR, "Unknown Transfer-Encoding: %s\n", colon);
 183                                 return -EINVAL;
 184                         }
 185                 }
 186                 if (header_cb && !strncmp(buf, "X-", 2))
 187                         header_cb(vpninfo, buf, colon);
 188         }
 189
 190         /* Handle 'HTTP/1.1 100 Continue'. Not that we should ever see it */
 191         if (*result == 100)
 192                 goto cont;
 193
 194         /* Now the body, if there is one */
 195         if (!bodylen)
 196                 goto fin;
 197
 198         if (http10) {
 199                 /* HTTP 1.0 response. Just eat all we can. */
 200                 while (1) {
 201                         i = SSL_read(vpninfo->https_ssl, body + done, bodylen - done);
 202                         if (i < 0)
 203                                 goto fin;
 204                         done += i;
 205                 }
 206         }
 207         /* If we were given Content-Length, it's nice and easy... */
 208         if (bodylen > 0) {
 209                 while (done < bodylen) {
 210                         i = SSL_read(vpninfo->https_ssl, body + done, bodylen - done);
 211                         if (i < 0) {
 212                                 vpninfo->progress(vpninfo, PRG_ERR, "Error reading HTTP response body\n");
 213                                 return -EINVAL;
 214                         }
 215                         done += i;
 216                 }
 217                 goto fin;
 218         }
 219
 220         /* ... else, chunked */
 221         while ((i = openconnect_SSL_gets(vpninfo->https_ssl, buf, sizeof(buf)))) {
 222                 int chunklen, lastchunk = 0;
 223
 224                 if (i < 0) {
 225                         vpninfo->progress(vpninfo, PRG_ERR, "Error fetching chunk header\n");
 226                         exit(1);
 227                 }
 228                 chunklen = strtol(buf, NULL, 16);
 229                 if (!chunklen) {
 230                         lastchunk = 1;
 231                         goto skip;
 232                 }
 233                 if (chunklen + done > buf_len) {
 234                         vpninfo->progress(vpninfo, PRG_ERR, "Response body too large for buffer (%d > %d)\n",
 235                                 chunklen + done, buf_len);
 236                         return -EINVAL;
 237                 }
 238                 while (chunklen) {
 239                         i = SSL_read(vpninfo->https_ssl, body + done, chunklen);
 240                         if (i < 0) {
 241                                 vpninfo->progress(vpninfo, PRG_ERR, "Error reading HTTP response body\n");
 242                                 return -EINVAL;
 243                         }
 244                         chunklen -= i;
 245                         done += i;
 246                 }
 247         skip:
 248                 if ((i = openconnect_SSL_gets(vpninfo->https_ssl, buf, sizeof(buf)))) {
 249                         if (i < 0) {
 250                                 vpninfo->progress(vpninfo, PRG_ERR, "Error fetching HTTP response body\n");
 251                         } else {
 252                                 vpninfo->progress(vpninfo, PRG_ERR, "Error in chunked decoding. Expected '', got: '%s'",
 253                                         buf);
 254                         }
 255                         return -EINVAL;
 256                 }
 257
 258                 if (lastchunk)
 259                         break;
 260         }
 261  fin:
 262         if (closeconn) {
 263                 SSL_free(vpninfo->https_ssl);
 264                 vpninfo->https_ssl = NULL;
 265                 close(vpninfo->ssl_fd);
 266                 vpninfo->ssl_fd = -1;
 267         }
 268         body[done] = 0;
 269         return done;
 270 }
 271
 272 static int fetch_config(struct openconnect_info *vpninfo, char *fu, char *bu,
 273                         char *server_sha1)
 274 {
 275         struct vpn_option *opt;
 276         char buf[MAX_BUF_LEN];
 277         int result, buflen;
 278         unsigned char local_sha1_bin[SHA_DIGEST_LENGTH];
 279         char local_sha1_ascii[(SHA_DIGEST_LENGTH * 2)+1];
 280         EVP_MD_CTX c;
 281         int i;
 282
 283         sprintf(buf, "GET %s%s HTTP/1.1\r\n", fu, bu);
 284         sprintf(buf + strlen(buf), "Host: %s\r\n", vpninfo->hostname);
 285         sprintf(buf + strlen(buf),  "User-Agent: %s\r\n", vpninfo->useragent);
 286         sprintf(buf + strlen(buf),  "Accept: */*\r\n");
 287         sprintf(buf + strlen(buf),  "Accept-Encoding: identity\r\n");
 288
 289         if (vpninfo->cookies) {
 290                 sprintf(buf + strlen(buf),  "Cookie: ");
 291                 for (opt = vpninfo->cookies; opt; opt = opt->next)
 292                         sprintf(buf + strlen(buf),  "%s=%s%s", opt->option,
 293                                       opt->value, opt->next ? "; " : "\r\n");
 294         }
 295         sprintf(buf + strlen(buf),  "X-Transcend-Version: 1\r\n\r\n");
 296
 297         SSL_write(vpninfo->https_ssl, buf, strlen(buf));
 298
 299         buflen = process_http_response(vpninfo, &result, NULL, buf, MAX_BUF_LEN);
 300         if (buflen < 0) {
 301                 /* We'll already have complained about whatever offended us */
 302                 return -EINVAL;
 303         }
 304
 305         if (result != 200)
 306                 return -EINVAL;
 307
 308
 309         EVP_MD_CTX_init(&c);
 310         EVP_Digest(buf, buflen, local_sha1_bin, NULL, EVP_sha1(), NULL);
 311         EVP_MD_CTX_cleanup(&c);
 312
 313         for (i = 0; i < SHA_DIGEST_LENGTH; i++)
 314                 sprintf(&local_sha1_ascii[i*2], "%02x", local_sha1_bin[i]);
 315
 316         if (strcasecmp(server_sha1, local_sha1_ascii)) {
 317                 vpninfo->progress(vpninfo, PRG_ERR, "Downloaded config file did not match intended SHA1\n");
 318                 return -EINVAL;
 319         }
 320
 321         return vpninfo->write_new_config(vpninfo, buf, buflen);
 322 }
 323
 324 static int run_csd_script(struct openconnect_info *vpninfo, char *buf, int buflen)
 325 {
 326         char fname[16];
 327         int fd;
 328
 329         if (!vpninfo->uid_csd_given) {
 330                 vpninfo->progress(vpninfo, PRG_ERR, "Error: You are trying to "
 331                                   "run insecure CSD code without specifying the CSD user.\n"
 332                                   "       Use command line option \"--csd-user\"\n");
 333                 exit(1);
 334         }
 335
 336 #ifndef __linux__
 337         vpninfo->progress(vpninfo, PRG_INFO,
 338                           "Trying to run Linux CSD trojan script.");
 339 #endif
 340
 341         sprintf(fname, "/tmp/csdXXXXXX");
 342         fd = mkstemp(fname);
 343         if (fd < 0) {
 344                 int err = -errno;
 345                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to open temporary CSD script file: %s\n",
 346                                   strerror(errno));
 347                 return err;
 348         }
 349         write(fd, buf, buflen);
 350         fchmod(fd, 0755);
 351         close(fd);
 352
 353         if (!fork()) {
 354                 X509 *scert = SSL_get_peer_certificate(vpninfo->https_ssl);
 355                 X509 *ccert = SSL_get_certificate(vpninfo->https_ssl);
 356                 char scertbuf[EVP_MAX_MD_SIZE * 2 + 1];
 357                 char ccertbuf[EVP_MAX_MD_SIZE * 2 + 1];
 358                 char *csd_argv[32];
 359                 int i = 0;
 360
 361                 if (vpninfo->uid_csd != getuid()) {
 362                         struct passwd *pw;
 363
 364                         if (setuid(vpninfo->uid_csd)) {
 365                                 fprintf(stderr, "Failed to set uid %d\n",
 366                                         vpninfo->uid_csd);
 367                                 exit(1);
 368                         }
 369                         if (!(pw = getpwuid(vpninfo->uid_csd))) {
 370                                 fprintf(stderr, "Invalid user uid=%d\n",
 371                                         vpninfo->uid_csd);
 372                                 exit(1);
 373                         }
 374                         setenv("HOME", pw->pw_dir, 1);
 375                         chdir(pw->pw_dir);
 376                 }
 377                 if (vpninfo->uid_csd == 0) {
 378                         fprintf(stderr, "Warning: you are running insecure "
 379                                 "CSD code with root privileges\n"
 380                                 "\t Use command line option \"--csd-user\"\n");
 381                 }
 382
 383                 csd_argv[i++] = fname;
 384                 csd_argv[i++] = "-ticket";
 385                 asprintf(&csd_argv[i++], "\"%s\"", vpninfo->csd_ticket);
 386                 csd_argv[i++] = "-stub";
 387                 csd_argv[i++] = "\"0\"";
 388                 csd_argv[i++] = "-group";
 389                 asprintf(&csd_argv[i++], "\"%s\"", vpninfo->authgroup?:"");
 390                 get_cert_md5_fingerprint(vpninfo, scert, scertbuf);
 391                 if (ccert)
 392                         get_cert_md5_fingerprint(vpninfo, ccert, ccertbuf);
 393                 else
 394                         ccertbuf[0] = 0;
 395
 396                 csd_argv[i++] = "-certhash";
 397                 asprintf(&csd_argv[i++], "\"%s:%s\"", scertbuf, ccertbuf);
 398                 csd_argv[i++] = "-url";
 399                 asprintf(&csd_argv[i++], "\"https://%s%s\"", vpninfo->hostname, vpninfo->csd_starturl);
 400                 /* WTF would it want to know this for? */
 401                 csd_argv[i++] = "-vpnclient";
 402                 csd_argv[i++] = "\"/opt/cisco/vpn/bin/vpnui";
 403                 csd_argv[i++] = "-connect";
 404                 asprintf(&csd_argv[i++], "https://%s/%s", vpninfo->hostname, vpninfo->csd_preurl);
 405                 csd_argv[i++] = "-connectparam";
 406                 asprintf(&csd_argv[i++], "#csdtoken=%s\"", vpninfo->csd_token);
 407                 csd_argv[i++] = "-langselen";
 408                 csd_argv[i++] = NULL;
 409
 410                 execv(fname, csd_argv);
 411                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to exec CSD script %s\n", fname);
 412                 exit(1);
 413         }
 414
 415         free(vpninfo->csd_stuburl);
 416         vpninfo->csd_stuburl = NULL;
 417         vpninfo->urlpath = strdup(vpninfo->csd_waiturl +
 418                                   (vpninfo->csd_waiturl[0] == '/' ? 1 : 0));
 419         vpninfo->csd_waiturl = NULL;
 420         vpninfo->csd_scriptname = strdup(fname);
 421
 422         http_add_cookie(vpninfo, "sdesktop", vpninfo->csd_token);
 423
 424         return 0;
 425 }
 426
 427 #ifdef __sun__
 428 char *local_strcasestr(const char *haystack, const char *needle)
 429 {
 430         int hlen = strlen(haystack);
 431         int nlen = strlen(needle);
 432         int i, j;
 433
 434         for (i = 0; i < hlen - nlen + 1; i++) {
 435                 for (j = 0; j < nlen; j++) {
 436                         if (tolower(haystack[i + j]) !=
 437                             tolower(needle[j]))
 438                                 break;
 439                 }
 440                 if (j == nlen)
 441                         return (char *)haystack + i;
 442         }
 443         return NULL;
 444 }
 445 #define strcasestr local_strcasestr
 446 #endif
 447
 448 /* Return value:
 449  *  < 0, on error
 450  *  = 0, no cookie (user cancel)
 451  *  = 1, obtained cookie
 452  */
 453 int openconnect_obtain_cookie(struct openconnect_info *vpninfo)
 454 {
 455         struct vpn_option *opt, *next;
 456         char buf[MAX_BUF_LEN];
 457         int result, buflen;
 458         char request_body[2048];
 459         char *request_body_type = NULL;
 460         char *method = "GET";
 461
 462  retry:
 463         if (!vpninfo->https_ssl && openconnect_open_https(vpninfo)) {
 464                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to open HTTPS connection to %s\n",
 465                         vpninfo->hostname);
 466                 return -EINVAL;
 467         }
 468
 469         /*
 470          * It would be nice to use cURL for this, but we really need to guarantee
 471          * that we'll be using OpenSSL (for the TPM stuff), and it doesn't seem
 472          * to have any way to let us provide our own socket read/write functions.
 473          * We can only provide a socket _open_ function. Which would require having
 474          * a socketpair() and servicing the "other" end of it.
 475          *
 476          * So we process the HTTP for ourselves...
 477          */
 478         sprintf(buf, "%s /%s HTTP/1.1\r\n", method, vpninfo->urlpath ?: "");
 479         sprintf(buf + strlen(buf), "Host: %s\r\n", vpninfo->hostname);
 480         sprintf(buf + strlen(buf),  "User-Agent: %s\r\n", vpninfo->useragent);
 481         sprintf(buf + strlen(buf),  "Accept: */*\r\n");
 482         sprintf(buf + strlen(buf),  "Accept-Encoding: identity\r\n");
 483
 484         if (vpninfo->cookies) {
 485                 sprintf(buf + strlen(buf),  "Cookie: ");
 486                 for (opt = vpninfo->cookies; opt; opt = opt->next)
 487                         sprintf(buf + strlen(buf),  "%s=%s%s", opt->option,
 488                                       opt->value, opt->next ? "; " : "\r\n");
 489         }
 490         if (request_body_type) {
 491                 sprintf(buf + strlen(buf),  "Content-Type: %s\r\n",
 492                               request_body_type);
 493                 sprintf(buf + strlen(buf),  "Content-Length: %zd\r\n",
 494                               strlen(request_body));
 495         }
 496         sprintf(buf + strlen(buf),  "X-Transcend-Version: 1\r\n\r\n");
 497         if (request_body_type)
 498                 sprintf(buf + strlen(buf), "%s", request_body);
 499
 500         if (vpninfo->port == 443)
 501                 vpninfo->progress(vpninfo, PRG_INFO, "%s https://%s/%s\n",
 502                                   method, vpninfo->hostname,
 503                                   vpninfo->urlpath ?: "");
 504         else
 505                 vpninfo->progress(vpninfo, PRG_INFO, "%s https://%s:%d/%s\n",
 506                                   method, vpninfo->hostname, vpninfo->port,
 507                                   vpninfo->urlpath ?: "");
 508
 509         SSL_write(vpninfo->https_ssl, buf, strlen(buf));
 510
 511         buflen = process_http_response(vpninfo, &result, NULL, buf, MAX_BUF_LEN);
 512         if (buflen < 0) {
 513                 /* We'll already have complained about whatever offended us */
 514                 exit(1);
 515         }
 516
 517         if (result != 200 && vpninfo->redirect_url) {
 518         redirect:
 519                 if (!strncmp(vpninfo->redirect_url, "https://", 8)) {
 520                         /* New host. Tear down the existing connection and make a new one */
 521                         char *host = vpninfo->redirect_url + 8;
 522                         char *path = strchr(host, '/');
 523                         int port = 443;
 524                         char *port_str;
 525
 526                         free(vpninfo->urlpath);
 527                         if (path) {
 528                                 *(path++) = 0;
 529                                 vpninfo->urlpath = strdup(path);
 530                         } else
 531                                 vpninfo->urlpath = NULL;
 532
 533                         port_str = strrchr(host, ':');
 534                         if (port_str) {
 535                                 char *end;
 536
 537                                 port = strtol(port_str + 1, &end, 10);
 538                                 if (!*end)
 539                                         *port_str = 0;
 540                                 else
 541                                         port = 443;
 542                         }
 543                         /* Check for IPv6 literal (RFC2732) */
 544                         if (host[0] == '[' && host[strlen(host)-1] == ']') {
 545                                 host[strlen(host)-1] = 0;
 546                                 host++;
 547                         }
 548                         if (strcmp(vpninfo->hostname, host) ||
 549                             port != vpninfo->port) {
 550                                 free(vpninfo->hostname);
 551                                 vpninfo->hostname = strdup(host);
 552                                 vpninfo->port = port;
 553
 554                                 /* Kill the existing connection, and a new one will happen */
 555                                 free(vpninfo->peer_addr);
 556                                 vpninfo->peer_addr = NULL;
 557                                 SSL_free(vpninfo->https_ssl);
 558                                 vpninfo->https_ssl = NULL;
 559                                 close(vpninfo->ssl_fd);
 560                                 vpninfo->ssl_fd = -1;
 561
 562                                 for (opt = vpninfo->cookies; opt; opt = next) {
 563                                         next = opt->next;
 564
 565                                         free(opt->option);
 566                                         free(opt->value);
 567                                         free(opt);
 568                                 }
 569                                 vpninfo->cookies = NULL;
 570                         }
 571                         free(vpninfo->redirect_url);
 572                         vpninfo->redirect_url = NULL;
 573
 574                         goto retry;
 575                 } else if (vpninfo->redirect_url[0] == '/') {
 576                         /* Absolute redirect within same host */
 577                         free(vpninfo->urlpath);
 578                         vpninfo->urlpath = strdup(vpninfo->redirect_url + 1);
 579                         free(vpninfo->redirect_url);
 580                         vpninfo->redirect_url = NULL;
 581                         goto retry;
 582                 } else {
 583                         vpninfo->progress(vpninfo, PRG_ERR, "Relative redirect (to '%s') not supported\n",
 584                                 vpninfo->redirect_url);
 585                         return -EINVAL;
 586                 }
 587         }
 588
 589         if (vpninfo->csd_stuburl) {
 590                 /* This is the CSD stub script, which we now need to run */
 591                 result = run_csd_script(vpninfo, buf, buflen);
 592                 if (result)
 593                         return result;
 594
 595                 /* Now we'll be redirected to the waiturl */
 596                 goto retry;
 597         }
 598         if (strncmp(buf, "<?xml", 5)) {
 599                 /* Not XML? Perhaps it's HTML with a refresh... */
 600                 if (strcasestr(buf, "http-equiv=\"refresh\"")) {
 601                         vpninfo->progress(vpninfo, PRG_INFO, "Refreshing %s after 1 second...\n",
 602                                           vpninfo->urlpath);
 603                         sleep(1);
 604                         goto retry;
 605                 }
 606                 vpninfo->progress(vpninfo, PRG_ERR, "Unknown response from server\n");
 607                 return -EINVAL;
 608         }
 609         request_body[0] = 0;
 610         result = parse_xml_response(vpninfo, buf, request_body, sizeof(request_body),
 611                                     &method, &request_body_type);
 612         if (!result)
 613                 goto redirect;
 614
 615         if (result != 2)
 616                 return result;
 617         /* A return value of 2 means the XML form indicated
 618            success. We _should_ have a cookie... */
 619
 620         for (opt = vpninfo->cookies; opt; opt = opt->next) {
 621
 622                 if (!strcmp(opt->option, "webvpn"))
 623                         vpninfo->cookie = opt->value;
 624                 else if (vpninfo->write_new_config && !strcmp(opt->option, "webvpnc")) {
 625                         char *tok = opt->value;
 626                         char *bu = NULL, *fu = NULL, *sha = NULL;
 627
 628                         do {
 629                                 if (tok != opt->value)
 630                                         *(tok++) = 0;
 631
 632                                 if (!strncmp(tok, "bu:", 3))
 633                                         bu = tok + 3;
 634                                 else if (!strncmp(tok, "fu:", 3))
 635                                         fu = tok + 3;
 636                                 else if (!strncmp(tok, "fh:", 3)) {
 637                                         if (!strncasecmp(tok+3, vpninfo->xmlsha1,
 638                                                          SHA_DIGEST_LENGTH * 2))
 639                                                 break;
 640                                         sha = tok + 3;
 641                                 }
 642                         } while ((tok = strchr(tok, '&')));
 643
 644                         if (bu && fu && sha)
 645                                 fetch_config(vpninfo, bu, fu, sha);
 646                 }
 647         }
 648         if (vpninfo->csd_scriptname) {
 649                 unlink(vpninfo->csd_scriptname);
 650                 free(vpninfo->csd_scriptname);
 651                 vpninfo->csd_scriptname = NULL;
 652         }
 653         return 0;
 654 }
 655
 656 char *openconnect_create_useragent(char *base)
 657 {
 658         char *uagent;
 659
 660         if (asprintf(&uagent, "%s %s", base, openconnect_version) < 0)
 661                 return NULL;
 662
 663         return uagent;
 664 }