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 static int process_http_response(struct openconnect_info *vpninfo, int *result,
  53                                  int (*header_cb)(struct openconnect_info *, char *, char *),
  54                                  char *body, int buf_len)
  55 {
  56         char buf[MAX_BUF_LEN];
  57         int bodylen = 0;
  58         int done = 0;
  59         int http10 = 0, closeconn = 0;
  60         int i;
  61
  62         if (openconnect_SSL_gets(vpninfo->https_ssl, buf, sizeof(buf)) < 0) {
  63                 vpninfo->progress(vpninfo, PRG_ERR, "Error fetching HTTPS response\n");
  64                 return -EINVAL;
  65         }
  66
  67  cont:
  68         if (!strncmp(buf, "HTTP/1.0 ", 9)) {
  69                 http10 = 1;
  70                 closeconn = 1;
  71         }
  72
  73         if ((!http10 && strncmp(buf, "HTTP/1.1 ", 9)) || !(*result = atoi(buf+9))) {
  74                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to parse HTTP response '%s'\n", buf);
  75                 return -EINVAL;
  76         }
  77
  78         vpninfo->progress(vpninfo, PRG_TRACE, "Got HTTP response: %s\n", buf);
  79
  80         /* Eat headers... */
  81         while ((i = openconnect_SSL_gets(vpninfo->https_ssl, buf, sizeof(buf)))) {
  82                 char *colon;
  83
  84                 vpninfo->progress(vpninfo, PRG_TRACE, "%s\n", buf);
  85
  86                 if (i < 0) {
  87                         vpninfo->progress(vpninfo, PRG_ERR, "Error processing HTTP response\n");
  88                         return -EINVAL;
  89                 }
  90                 colon = strchr(buf, ':');
  91                 if (!colon) {
  92                         vpninfo->progress(vpninfo, PRG_ERR, "Ignoring unknown HTTP response line '%s'\n", buf);
  93                         continue;
  94                 }
  95                 *(colon++) = 0;
  96                 if (*colon == ' ')
  97                         colon++;
  98
  99                 if (!strcmp(buf, "Connection") && !strcmp(colon, "Close"))
 100                         closeconn = 1;
 101
 102                 if (!strcmp(buf, "Location")) {
 103                         vpninfo->redirect_url = strdup(colon);
 104                         if (!vpninfo->redirect_url)
 105                                 return -ENOMEM;
 106                 }
 107                 if (!strcmp(buf, "Content-Length")) {
 108                         bodylen = atoi(colon);
 109                         if (bodylen < 0 || bodylen > buf_len) {
 110                                 vpninfo->progress(vpninfo, PRG_ERR, "Response body too large for buffer (%d > %d)\n",
 111                                         bodylen, buf_len);
 112                                 return -EINVAL;
 113                         }
 114                 }
 115                 if (!strcmp(buf, "Set-Cookie")) {
 116                         struct vpn_option *new, **this;
 117                         char *semicolon = strchr(colon, ';');
 118                         char *equals = strchr(colon, '=');
 119
 120                         if (semicolon)
 121                                 *semicolon = 0;
 122
 123                         if (!equals) {
 124                                 vpninfo->progress(vpninfo, PRG_ERR, "Invalid cookie offered: %s\n", buf);
 125                                 return -EINVAL;
 126                         }
 127                         *(equals++) = 0;
 128
 129                         if (*equals) {
 130                                 new = malloc(sizeof(*new));
 131                                 if (!new) {
 132                                         vpninfo->progress(vpninfo, PRG_ERR, "No memory for allocating cookies\n");
 133                                         return -ENOMEM;
 134                                 }
 135                                 new->next = NULL;
 136                                 new->option = strdup(colon);
 137                                 new->value = strdup(equals);
 138                         } else {
 139                                 /* Kill cookie; don't replace it */
 140                                 new = NULL;
 141                         }
 142                         for (this = &vpninfo->cookies; *this; this = &(*this)->next) {
 143                                 if (!strcmp(colon, (*this)->option)) {
 144                                         /* Replace existing cookie */
 145                                         if (new)
 146                                                 new->next = (*this)->next;
 147                                         else
 148                                                 new = (*this)->next;
 149
 150                                         free((*this)->option);
 151                                         free((*this)->value);
 152                                         free(*this);
 153                                         *this = new;
 154                                         break;
 155                                 }
 156                         }
 157                         if (new && !*this) {
 158                                 *this = new;
 159                                 new->next = NULL;
 160                         }
 161                 }
 162                 if (!strcmp(buf, "Transfer-Encoding")) {
 163                         if (!strcmp(colon, "chunked"))
 164                                 bodylen = -1;
 165                         else {
 166                                 vpninfo->progress(vpninfo, PRG_ERR, "Unknown Transfer-Encoding: %s\n", colon);
 167                                 return -EINVAL;
 168                         }
 169                 }
 170                 if (header_cb && !strncmp(buf, "X-", 2))
 171                         header_cb(vpninfo, buf, colon);
 172         }
 173
 174         /* Handle 'HTTP/1.1 100 Continue'. Not that we should ever see it */
 175         if (*result == 100)
 176                 goto cont;
 177
 178         /* Now the body, if there is one */
 179         if (!bodylen)
 180                 goto fin;
 181
 182         if (http10) {
 183                 /* HTTP 1.0 response. Just eat all we can. */
 184                 while (1) {
 185                         i = SSL_read(vpninfo->https_ssl, body + done, bodylen - done);
 186                         if (i < 0)
 187                                 goto fin;
 188                         done += i;
 189                 }
 190         }
 191         /* If we were given Content-Length, it's nice and easy... */
 192         if (bodylen > 0) {
 193                 while (done < bodylen) {
 194                         i = SSL_read(vpninfo->https_ssl, body + done, bodylen - done);
 195                         if (i < 0) {
 196                                 vpninfo->progress(vpninfo, PRG_ERR, "Error reading HTTP response body\n");
 197                                 return -EINVAL;
 198                         }
 199                         done += i;
 200                 }
 201                 goto fin;
 202         }
 203
 204         /* ... else, chunked */
 205         while ((i = openconnect_SSL_gets(vpninfo->https_ssl, buf, sizeof(buf)))) {
 206                 int chunklen, lastchunk = 0;
 207
 208                 if (i < 0) {
 209                         vpninfo->progress(vpninfo, PRG_ERR, "Error fetching chunk header\n");
 210                         exit(1);
 211                 }
 212                 chunklen = strtol(buf, NULL, 16);
 213                 if (!chunklen) {
 214                         lastchunk = 1;
 215                         goto skip;
 216                 }
 217                 if (chunklen + done > buf_len) {
 218                         vpninfo->progress(vpninfo, PRG_ERR, "Response body too large for buffer (%d > %d)\n",
 219                                 chunklen + done, buf_len);
 220                         return -EINVAL;
 221                 }
 222                 while (chunklen) {
 223                         i = SSL_read(vpninfo->https_ssl, body + done, chunklen);
 224                         if (i < 0) {
 225                                 vpninfo->progress(vpninfo, PRG_ERR, "Error reading HTTP response body\n");
 226                                 return -EINVAL;
 227                         }
 228                         chunklen -= i;
 229                         done += i;
 230                 }
 231         skip:
 232                 if ((i = openconnect_SSL_gets(vpninfo->https_ssl, buf, sizeof(buf)))) {
 233                         if (i < 0) {
 234                                 vpninfo->progress(vpninfo, PRG_ERR, "Error fetching HTTP response body\n");
 235                         } else {
 236                                 vpninfo->progress(vpninfo, PRG_ERR, "Error in chunked decoding. Expected '', got: '%s'",
 237                                         buf);
 238                         }
 239                         return -EINVAL;
 240                 }
 241
 242                 if (lastchunk)
 243                         break;
 244         }
 245  fin:
 246         if (closeconn) {
 247                 SSL_free(vpninfo->https_ssl);
 248                 vpninfo->https_ssl = NULL;
 249                 close(vpninfo->ssl_fd);
 250                 vpninfo->ssl_fd = -1;
 251         }
 252         body[done] = 0;
 253         return done;
 254 }
 255
 256 static int fetch_config(struct openconnect_info *vpninfo, char *fu, char *bu,
 257                         char *server_sha1)
 258 {
 259         struct vpn_option *opt;
 260         char buf[MAX_BUF_LEN];
 261         int result, buflen;
 262         unsigned char local_sha1_bin[SHA_DIGEST_LENGTH];
 263         char local_sha1_ascii[(SHA_DIGEST_LENGTH * 2)+1];
 264         EVP_MD_CTX c;
 265         int i;
 266
 267         sprintf(buf, "GET %s%s HTTP/1.1\r\n", fu, bu);
 268         sprintf(buf + strlen(buf), "Host: %s\r\n", vpninfo->hostname);
 269         sprintf(buf + strlen(buf),  "User-Agent: %s\r\n", vpninfo->useragent);
 270         sprintf(buf + strlen(buf),  "Accept: */*\r\n");
 271         sprintf(buf + strlen(buf),  "Accept-Encoding: identity\r\n");
 272
 273         if (vpninfo->cookies) {
 274                 sprintf(buf + strlen(buf),  "Cookie: ");
 275                 for (opt = vpninfo->cookies; opt; opt = opt->next)
 276                         sprintf(buf + strlen(buf),  "%s=%s%s", opt->option,
 277                                       opt->value, opt->next ? "; " : "\r\n");
 278         }
 279         sprintf(buf + strlen(buf),  "X-Transcend-Version: 1\r\n\r\n");
 280
 281         SSL_write(vpninfo->https_ssl, buf, strlen(buf));
 282
 283         buflen = process_http_response(vpninfo, &result, NULL, buf, MAX_BUF_LEN);
 284         if (buflen < 0) {
 285                 /* We'll already have complained about whatever offended us */
 286                 return -EINVAL;
 287         }
 288
 289         if (result != 200)
 290                 return -EINVAL;
 291
 292
 293         EVP_MD_CTX_init(&c);
 294         EVP_Digest(buf, buflen, local_sha1_bin, NULL, EVP_sha1(), NULL);
 295         EVP_MD_CTX_cleanup(&c);
 296
 297         for (i = 0; i < SHA_DIGEST_LENGTH; i++)
 298                 sprintf(&local_sha1_ascii[i*2], "%02x", local_sha1_bin[i]);
 299
 300         if (strcasecmp(server_sha1, local_sha1_ascii)) {
 301                 vpninfo->progress(vpninfo, PRG_ERR, "Downloaded config file did not match intended SHA1\n");
 302                 return -EINVAL;
 303         }
 304
 305         return vpninfo->write_new_config(vpninfo, buf, buflen);
 306 }
 307
 308 static int run_csd_script(struct openconnect_info *vpninfo, char *buf, int buflen)
 309 {
 310         char fname[16];
 311         int fd;
 312
 313         if (!vpninfo->uid_csd_given) {
 314                 vpninfo->progress(vpninfo, PRG_ERR, "Error: You are trying to "
 315                                   "run unsecure CSD code without specifying the CSD user.\n"
 316                                   "       Use command line option \"--setuid-csd\"\n");
 317                 exit(1);
 318         }
 319
 320         sprintf(fname, "/tmp/csdXXXXXX");
 321         fd = mkstemp(fname);
 322         if (fd < 0) {
 323                 int err = -errno;
 324                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to open temporary CSD script file: %s\n",
 325                                   strerror(errno));
 326                 return err;
 327         }
 328         write(fd, buf, buflen);
 329         fchmod(fd, 0755);
 330         close(fd);
 331
 332         if (!fork()) {
 333                 X509 *cert = SSL_get_peer_certificate(vpninfo->https_ssl);
 334                 char certbuf[EVP_MAX_MD_SIZE * 2 + 1];
 335                 char *csd_argv[32];
 336                 int i = 0;
 337
 338                 if (vpninfo->uid_csd != getuid()) {
 339                         struct passwd *pw;
 340
 341                         if (setuid(vpninfo->uid_csd)) {
 342                                 fprintf(stderr, "Failed to set uid %d\n",
 343                                         vpninfo->uid_csd);
 344                                 exit(1);
 345                         }
 346                         if (!(pw = getpwuid(vpninfo->uid_csd))) {
 347                                 fprintf(stderr, "Invalid user uid=%d\n",
 348                                         vpninfo->uid_csd);
 349                                 exit(1);
 350                         }
 351                         setenv("HOME", pw->pw_dir, 1);
 352                         chdir(pw->pw_dir);
 353                 }
 354                 if (vpninfo->uid_csd == 0) {
 355                         fprintf(stderr, "Warning: you are running unsecure "
 356                                 "CSD code with root privileges\n"
 357                                 "\t Use command line option \"--setuid-csd\"\n");
 358                 }
 359
 360                 csd_argv[i++] = fname;
 361                 csd_argv[i++] = "-ticket";
 362                 asprintf(&csd_argv[i++], "\"%s\"", vpninfo->csd_ticket);
 363                 csd_argv[i++] = "-stub";
 364                 csd_argv[i++] = "\"0\"";
 365                 csd_argv[i++] = "-group";
 366                 asprintf(&csd_argv[i++], "\"%s\"", vpninfo->authgroup?:"");
 367                 get_cert_md5_fingerprint(vpninfo, cert, certbuf);
 368                 csd_argv[i++] = "-certhash";
 369                 asprintf(&csd_argv[i++], "\"%s:%s\"", certbuf, vpninfo->cert_md5_fingerprint ?: "");
 370                 csd_argv[i++] = "-url";
 371                 asprintf(&csd_argv[i++], "\"https://%s%s\"", vpninfo->hostname, vpninfo->csd_starturl);
 372                 /* WTF would it want to know this for? */
 373                 csd_argv[i++] = "-vpnclient";
 374                 csd_argv[i++] = "\"/opt/cisco/vpn/bin/vpnui";
 375                 csd_argv[i++] = "-connect";
 376                 asprintf(&csd_argv[i++], "https://%s/%s", vpninfo->hostname, vpninfo->csd_preurl);
 377                 csd_argv[i++] = "-connectparam";
 378                 asprintf(&csd_argv[i++], "#csdtoken=%s\"", vpninfo->csd_token);
 379                 csd_argv[i++] = "-langselen";
 380                 csd_argv[i++] = NULL;
 381
 382                 execv(fname, csd_argv);
 383                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to exec CSD script %s\n", fname);
 384                 exit(1);
 385         }
 386
 387         free(vpninfo->csd_stuburl);
 388         vpninfo->csd_stuburl = NULL;
 389         vpninfo->urlpath = strdup(vpninfo->csd_waiturl +
 390                                   (vpninfo->csd_waiturl[0] == '/' ? 1 : 0));
 391         vpninfo->csd_waiturl = NULL;
 392         vpninfo->csd_scriptname = strdup(fname);
 393
 394         /* AB: add cookie "sdesktop=__TOKEN__" */
 395         {
 396                 struct vpn_option *new, **this;
 397                 new = malloc(sizeof(*new));
 398                 if (!new) {
 399                         vpninfo->progress(vpninfo, PRG_ERR, "No memory for allocating cookies\n");
 400                         return -ENOMEM;
 401                 }
 402                 new->next = NULL;
 403                 new->option = strdup("sdesktop");
 404                 new->value = strdup(vpninfo->csd_token);
 405
 406                 for (this = &vpninfo->cookies; *this; this = &(*this)->next) {
 407                         if (!strcmp(new->option, (*this)->option)) {
 408                                 /* Replace existing cookie */
 409                                 if (new)
 410                                         new->next = (*this)->next;
 411                                 else
 412                                         new = (*this)->next;
 413
 414                                 free((*this)->option);
 415                                 free((*this)->value);
 416                                 free(*this);
 417                                 *this = new;
 418                                 break;
 419                         }
 420                 }
 421                 if (new && !*this) {
 422                         *this = new;
 423                         new->next = NULL;
 424                 }
 425         }
 426         return 0;
 427 }
 428
 429 #ifdef __sun__
 430 char *local_strcasestr(const char *haystack, const char *needle)
 431 {
 432         int hlen = strlen(haystack);
 433         int nlen = strlen(needle);
 434         int i, j;
 435
 436         for (i = 0; i < hlen - nlen + 1; i++) {
 437                 for (j = 0; j < nlen; j++) {
 438                         if (tolower(haystack[i + j]) !=
 439                             tolower(needle[j]))
 440                                 break;
 441                 }
 442                 if (j == nlen)
 443                         return (char *)haystack + i;
 444         }
 445         return NULL;
 446 }
 447 #define strcasestr local_strcasestr
 448 #endif
 449
 450 /* Return value:
 451  *  < 0, on error
 452  *  = 0, no cookie (user cancel)
 453  *  = 1, obtained cookie
 454  */
 455 int openconnect_obtain_cookie(struct openconnect_info *vpninfo)
 456 {
 457         struct vpn_option *opt, *next;
 458         char buf[MAX_BUF_LEN];
 459         int result, buflen;
 460         char request_body[2048];
 461         char *request_body_type = NULL;
 462         char *method = "GET";
 463
 464  retry:
 465         if (!vpninfo->https_ssl && openconnect_open_https(vpninfo)) {
 466                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to open HTTPS connection to %s\n",
 467                         vpninfo->hostname);
 468                 return -EINVAL;
 469         }
 470
 471         /*
 472          * It would be nice to use cURL for this, but we really need to guarantee
 473          * that we'll be using OpenSSL (for the TPM stuff), and it doesn't seem
 474          * to have any way to let us provide our own socket read/write functions.
 475          * We can only provide a socket _open_ function. Which would require having
 476          * a socketpair() and servicing the "other" end of it.
 477          *
 478          * So we process the HTTP for ourselves...
 479          */
 480         sprintf(buf, "%s /%s HTTP/1.1\r\n", method, vpninfo->urlpath ?: "");
 481         sprintf(buf + strlen(buf), "Host: %s\r\n", vpninfo->hostname);
 482         sprintf(buf + strlen(buf),  "User-Agent: %s\r\n", vpninfo->useragent);
 483         sprintf(buf + strlen(buf),  "Accept: */*\r\n");
 484         sprintf(buf + strlen(buf),  "Accept-Encoding: identity\r\n");
 485
 486         if (vpninfo->cookies) {
 487                 sprintf(buf + strlen(buf),  "Cookie: ");
 488                 for (opt = vpninfo->cookies; opt; opt = opt->next)
 489                         sprintf(buf + strlen(buf),  "%s=%s%s", opt->option,
 490                                       opt->value, opt->next ? "; " : "\r\n");
 491         }
 492         if (request_body_type) {
 493                 sprintf(buf + strlen(buf),  "Content-Type: %s\r\n",
 494                               request_body_type);
 495                 sprintf(buf + strlen(buf),  "Content-Length: %zd\r\n",
 496                               strlen(request_body));
 497         }
 498         sprintf(buf + strlen(buf),  "X-Transcend-Version: 1\r\n\r\n");
 499         if (request_body_type)
 500                 sprintf(buf + strlen(buf), "%s", request_body);
 501
 502         vpninfo->progress(vpninfo, PRG_INFO, "%s %s/%s\n", method,
 503                           vpninfo->hostname, vpninfo->urlpath ?: "");
 504
 505         SSL_write(vpninfo->https_ssl, buf, strlen(buf));
 506
 507         buflen = process_http_response(vpninfo, &result, NULL, buf, MAX_BUF_LEN);
 508         if (buflen < 0) {
 509                 /* We'll already have complained about whatever offended us */
 510                 exit(1);
 511         }
 512
 513         if (result != 200 && vpninfo->redirect_url) {
 514         redirect:
 515                 if (!strncmp(vpninfo->redirect_url, "https://", 8)) {
 516                         /* New host. Tear down the existing connection and make a new one */
 517                         char *host = vpninfo->redirect_url + 8;
 518                         char *path = strchr(host, '/');
 519
 520                         free(vpninfo->urlpath);
 521                         if (path) {
 522                                 *(path++) = 0;
 523                                 vpninfo->urlpath = strdup(path);
 524                         } else
 525                                 vpninfo->urlpath = NULL;
 526
 527                         if (strcmp(vpninfo->hostname, host)) {
 528                                 free(vpninfo->hostname);
 529                                 vpninfo->hostname = strdup(host);
 530
 531                                 /* Kill the existing connection, and a new one will happen */
 532                                 SSL_free(vpninfo->https_ssl);
 533                                 vpninfo->https_ssl = NULL;
 534                                 close(vpninfo->ssl_fd);
 535                                 vpninfo->ssl_fd = -1;
 536
 537                                 for (opt = vpninfo->cookies; opt; opt = next) {
 538                                         next = opt->next;
 539
 540                                         free(opt->option);
 541                                         free(opt->value);
 542                                         free(opt);
 543                                 }
 544                                 vpninfo->cookies = NULL;
 545                         }
 546                         free(vpninfo->redirect_url);
 547                         vpninfo->redirect_url = NULL;
 548
 549                         goto retry;
 550                 } else if (vpninfo->redirect_url[0] == '/') {
 551                         /* Absolute redirect within same host */
 552                         free(vpninfo->urlpath);
 553                         vpninfo->urlpath = strdup(vpninfo->redirect_url + 1);
 554                         free(vpninfo->redirect_url);
 555                         vpninfo->redirect_url = NULL;
 556                         goto retry;
 557                 } else {
 558                         vpninfo->progress(vpninfo, PRG_ERR, "Relative redirect (to '%s') not supported\n",
 559                                 vpninfo->redirect_url);
 560                         return -EINVAL;
 561                 }
 562         }
 563
 564         if (vpninfo->csd_stuburl) {
 565                 /* This is the CSD stub script, which we now need to run */
 566                 result = run_csd_script(vpninfo, buf, buflen);
 567                 if (result)
 568                         return result;
 569
 570                 /* Now we'll be redirected to the waiturl */
 571                 goto retry;
 572         }
 573         if (strncmp(buf, "<?xml", 5)) {
 574                 /* Not XML? Perhaps it's HTML with a refresh... */
 575                 if (strcasestr(buf, "http-equiv=\"refresh\"")) {
 576                         vpninfo->progress(vpninfo, PRG_INFO, "Refreshing %s after 1 second...\n",
 577                                           vpninfo->urlpath);
 578                         sleep(1);
 579                         goto retry;
 580                 }
 581                 vpninfo->progress(vpninfo, PRG_ERR, "Unknown response from server\n");
 582                 return -EINVAL;
 583         }
 584         request_body[0] = 0;
 585         result = parse_xml_response(vpninfo, buf, request_body, sizeof(request_body),
 586                                     &method, &request_body_type);
 587         if (!result)
 588                 goto redirect;
 589
 590         if (result != 2)
 591                 return result;
 592         /* A return value of 2 means the XML form indicated
 593            success. We _should_ have a cookie... */
 594
 595         for (opt = vpninfo->cookies; opt; opt = opt->next) {
 596
 597                 if (!strcmp(opt->option, "webvpn"))
 598                         vpninfo->cookie = opt->value;
 599                 else if (vpninfo->write_new_config && !strcmp(opt->option, "webvpnc")) {
 600                         char *tok = opt->value;
 601                         char *bu = NULL, *fu = NULL, *sha = NULL;
 602
 603                         do {
 604                                 if (tok != opt->value)
 605                                         *(tok++) = 0;
 606
 607                                 if (!strncmp(tok, "bu:", 3))
 608                                         bu = tok + 3;
 609                                 else if (!strncmp(tok, "fu:", 3))
 610                                         fu = tok + 3;
 611                                 else if (!strncmp(tok, "fh:", 3)) {
 612                                         if (!strncasecmp(tok+3, vpninfo->xmlsha1,
 613                                                          SHA_DIGEST_LENGTH * 2))
 614                                                 break;
 615                                         sha = tok + 3;
 616                                 }
 617                         } while ((tok = strchr(tok, '&')));
 618
 619                         if (bu && fu && sha)
 620                                 fetch_config(vpninfo, bu, fu, sha);
 621                 }
 622         }
 623         if (vpninfo->csd_scriptname) {
 624                 unlink(vpninfo->csd_scriptname);
 625                 free(vpninfo->csd_scriptname);
 626                 vpninfo->csd_scriptname = NULL;
 627         }
 628         return 0;
 629 }
 630
 631 char *openconnect_create_useragent(char *base)
 632 {
 633         char *uagent = malloc(strlen(base) + 1 + strlen(openconnect_version));
 634         sprintf(uagent, "%s %s", base, openconnect_version);
 635         return uagent;
 636 }