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         sprintf(fname, "/tmp/csdXXXXXX");
 314         fd = mkstemp(fname);
 315         if (fd < 0) {
 316                 int err = -errno;
 317                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to open temporary CSD script file: %s\n",
 318                                   strerror(errno));
 319                 return err;
 320         }
 321         write(fd, buf, buflen);
 322         fchmod(fd, 0755);
 323         close(fd);
 324
 325         if (!fork()) {
 326                 X509 *cert = SSL_get_peer_certificate(vpninfo->https_ssl);
 327                 char certbuf[EVP_MAX_MD_SIZE * 2 + 1];
 328                 char *csd_argv[32];
 329                 int i = 0;
 330
 331                 if (vpninfo->uid != getuid()) {
 332                         struct passwd *pw;
 333
 334                         if (setuid(vpninfo->uid)) {
 335                                 fprintf(stderr, "Failed to set uid %d\n",
 336                                         vpninfo->uid);
 337                                 exit(1);
 338                         }
 339                         if (!(pw = getpwuid(vpninfo->uid))) {
 340                                 fprintf(stderr, "Invalid user uid=%d\n",
 341                                         vpninfo->uid);
 342                                 exit(1);
 343                         }
 344                         setenv("HOME", pw->pw_dir, 1);
 345                         chdir(pw->pw_dir);
 346                 }
 347                 if (vpninfo->uid == 0) {
 348                         fprintf(stderr, "Warning: you are running unsecure "
 349                                 "CSD code with root privileges\n"
 350                                 "\t Use command line option \"-U\"\n");
 351                 }
 352
 353                 csd_argv[i++] = fname;
 354                 csd_argv[i++] = "-ticket";
 355                 asprintf(&csd_argv[i++], "\"%s\"", vpninfo->csd_ticket);
 356                 csd_argv[i++] = "-stub";
 357                 csd_argv[i++] = "\"0\"";
 358                 csd_argv[i++] = "-group";
 359                 asprintf(&csd_argv[i++], "\"%s\"", vpninfo->authgroup?:"");
 360                 get_cert_md5_fingerprint(vpninfo, cert, certbuf);
 361                 csd_argv[i++] = "-certhash";
 362                 asprintf(&csd_argv[i++], "\"%s:%s\"", certbuf, vpninfo->cert_md5_fingerprint ?: "");
 363                 csd_argv[i++] = "-url";
 364                 asprintf(&csd_argv[i++], "\"https://%s%s\"", vpninfo->hostname, vpninfo->csd_starturl);
 365                 /* WTF would it want to know this for? */
 366                 csd_argv[i++] = "-vpnclient";
 367                 csd_argv[i++] = "\"/opt/cisco/vpn/bin/vpnui";
 368                 csd_argv[i++] = "-connect";
 369                 asprintf(&csd_argv[i++], "https://%s/%s", vpninfo->hostname, vpninfo->csd_preurl);
 370                 csd_argv[i++] = "-connectparam";
 371                 asprintf(&csd_argv[i++], "#csdtoken=%s\"", vpninfo->csd_token);
 372                 csd_argv[i++] = "-langselen";
 373                 csd_argv[i++] = NULL;
 374
 375                 execv(fname, csd_argv);
 376                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to exec CSD script %s\n", fname);
 377                 exit(1);
 378         }
 379
 380         free(vpninfo->csd_stuburl);
 381         vpninfo->csd_stuburl = NULL;
 382         vpninfo->urlpath = strdup(vpninfo->csd_waiturl +
 383                                   (vpninfo->csd_waiturl[0] == '/' ? 1 : 0));
 384         vpninfo->csd_waiturl = NULL;
 385         vpninfo->csd_scriptname = strdup(fname);
 386
 387         /* AB: add cookie "sdesktop=__TOKEN__" */
 388         {
 389                 struct vpn_option *new, **this;
 390                 new = malloc(sizeof(*new));
 391                 if (!new) {
 392                         vpninfo->progress(vpninfo, PRG_ERR, "No memory for allocating cookies\n");
 393                         return -ENOMEM;
 394                 }
 395                 new->next = NULL;
 396                 new->option = strdup("sdesktop");
 397                 new->value = strdup(vpninfo->csd_token);
 398
 399                 for (this = &vpninfo->cookies; *this; this = &(*this)->next) {
 400                         if (!strcmp(new->option, (*this)->option)) {
 401                                 /* Replace existing cookie */
 402                                 if (new)
 403                                         new->next = (*this)->next;
 404                                 else
 405                                         new = (*this)->next;
 406
 407                                 free((*this)->option);
 408                                 free((*this)->value);
 409                                 free(*this);
 410                                 *this = new;
 411                                 break;
 412                         }
 413                 }
 414                 if (new && !*this) {
 415                         *this = new;
 416                         new->next = NULL;
 417                 }
 418         }
 419         return 0;
 420 }
 421
 422 /* Return value:
 423  *  < 0, on error
 424  *  = 0, no cookie (user cancel)
 425  *  = 1, obtained cookie
 426  */
 427 int openconnect_obtain_cookie(struct openconnect_info *vpninfo)
 428 {
 429         struct vpn_option *opt, *next;
 430         char buf[MAX_BUF_LEN];
 431         int result, buflen;
 432         char request_body[2048];
 433         char *request_body_type = NULL;
 434         char *method = "GET";
 435
 436  retry:
 437         if (!vpninfo->https_ssl && openconnect_open_https(vpninfo)) {
 438                 vpninfo->progress(vpninfo, PRG_ERR, "Failed to open HTTPS connection to %s\n",
 439                         vpninfo->hostname);
 440                 return -EINVAL;
 441         }
 442
 443         /*
 444          * It would be nice to use cURL for this, but we really need to guarantee
 445          * that we'll be using OpenSSL (for the TPM stuff), and it doesn't seem
 446          * to have any way to let us provide our own socket read/write functions.
 447          * We can only provide a socket _open_ function. Which would require having
 448          * a socketpair() and servicing the "other" end of it.
 449          *
 450          * So we process the HTTP for ourselves...
 451          */
 452         sprintf(buf, "%s /%s HTTP/1.1\r\n", method, vpninfo->urlpath ?: "");
 453         sprintf(buf + strlen(buf), "Host: %s\r\n", vpninfo->hostname);
 454         sprintf(buf + strlen(buf),  "User-Agent: %s\r\n", vpninfo->useragent);
 455         sprintf(buf + strlen(buf),  "Accept: */*\r\n");
 456         sprintf(buf + strlen(buf),  "Accept-Encoding: identity\r\n");
 457
 458         if (vpninfo->cookies) {
 459                 sprintf(buf + strlen(buf),  "Cookie: ");
 460                 for (opt = vpninfo->cookies; opt; opt = opt->next)
 461                         sprintf(buf + strlen(buf),  "%s=%s%s", opt->option,
 462                                       opt->value, opt->next ? "; " : "\r\n");
 463         }
 464         if (request_body_type) {
 465                 sprintf(buf + strlen(buf),  "Content-Type: %s\r\n",
 466                               request_body_type);
 467                 sprintf(buf + strlen(buf),  "Content-Length: %zd\r\n",
 468                               strlen(request_body));
 469         }
 470         sprintf(buf + strlen(buf),  "X-Transcend-Version: 1\r\n\r\n");
 471         if (request_body_type)
 472                 sprintf(buf + strlen(buf), "%s", request_body);
 473
 474         vpninfo->progress(vpninfo, PRG_INFO, "%s %s/%s\n", method,
 475                           vpninfo->hostname, vpninfo->urlpath ?: "");
 476
 477         SSL_write(vpninfo->https_ssl, buf, strlen(buf));
 478
 479         buflen = process_http_response(vpninfo, &result, NULL, buf, MAX_BUF_LEN);
 480         if (buflen < 0) {
 481                 /* We'll already have complained about whatever offended us */
 482                 exit(1);
 483         }
 484
 485         if (result != 200 && vpninfo->redirect_url) {
 486         redirect:
 487                 if (!strncmp(vpninfo->redirect_url, "https://", 8)) {
 488                         /* New host. Tear down the existing connection and make a new one */
 489                         char *host = vpninfo->redirect_url + 8;
 490                         char *path = strchr(host, '/');
 491
 492                         free(vpninfo->urlpath);
 493                         if (path) {
 494                                 *(path++) = 0;
 495                                 vpninfo->urlpath = strdup(path);
 496                         } else
 497                                 vpninfo->urlpath = NULL;
 498
 499                         if (strcmp(vpninfo->hostname, host)) {
 500                                 free(vpninfo->hostname);
 501                                 vpninfo->hostname = strdup(host);
 502
 503                                 /* Kill the existing connection, and a new one will happen */
 504                                 SSL_free(vpninfo->https_ssl);
 505                                 vpninfo->https_ssl = NULL;
 506                                 close(vpninfo->ssl_fd);
 507                                 vpninfo->ssl_fd = -1;
 508
 509                                 for (opt = vpninfo->cookies; opt; opt = next) {
 510                                         next = opt->next;
 511
 512                                         free(opt->option);
 513                                         free(opt->value);
 514                                         free(opt);
 515                                 }
 516                                 vpninfo->cookies = NULL;
 517                         }
 518                         free(vpninfo->redirect_url);
 519                         vpninfo->redirect_url = NULL;
 520
 521                         goto retry;
 522                 } else if (vpninfo->redirect_url[0] == '/') {
 523                         /* Absolute redirect within same host */
 524                         free(vpninfo->urlpath);
 525                         vpninfo->urlpath = strdup(vpninfo->redirect_url + 1);
 526                         free(vpninfo->redirect_url);
 527                         vpninfo->redirect_url = NULL;
 528                         goto retry;
 529                 } else {
 530                         vpninfo->progress(vpninfo, PRG_ERR, "Relative redirect (to '%s') not supported\n",
 531                                 vpninfo->redirect_url);
 532                         return -EINVAL;
 533                 }
 534         }
 535
 536         if (vpninfo->csd_stuburl) {
 537                 /* This is the CSD stub script, which we now need to run */
 538                 result = run_csd_script(vpninfo, buf, buflen);
 539                 if (result)
 540                         return result;
 541
 542                 /* Now we'll be redirected to the waiturl */
 543                 goto retry;
 544         }
 545         if (strncmp(buf, "<?xml", 5)) {
 546                 /* Not XML? Perhaps it's HTML with a refresh... */
 547                 if (strcasestr(buf, "http-equiv=\"refresh\"")) {
 548                         vpninfo->progress(vpninfo, PRG_INFO, "Refreshing %s after 1 second...\n",
 549                                           vpninfo->urlpath);
 550                         sleep(1);
 551                         goto retry;
 552                 }
 553                 vpninfo->progress(vpninfo, PRG_ERR, "Unknown response from server\n");
 554                 return -EINVAL;
 555         }
 556         request_body[0] = 0;
 557         result = parse_xml_response(vpninfo, buf, request_body, sizeof(request_body),
 558                                     &method, &request_body_type);
 559         if (!result)
 560                 goto redirect;
 561
 562         if (result != 2)
 563                 return result;
 564         /* A return value of 2 means the XML form indicated
 565            success. We _should_ have a cookie... */
 566
 567         for (opt = vpninfo->cookies; opt; opt = opt->next) {
 568
 569                 if (!strcmp(opt->option, "webvpn"))
 570                         vpninfo->cookie = opt->value;
 571                 else if (vpninfo->write_new_config && !strcmp(opt->option, "webvpnc")) {
 572                         char *tok = opt->value;
 573                         char *bu = NULL, *fu = NULL, *sha = NULL;
 574
 575                         do {
 576                                 if (tok != opt->value)
 577                                         *(tok++) = 0;
 578
 579                                 if (!strncmp(tok, "bu:", 3))
 580                                         bu = tok + 3;
 581                                 else if (!strncmp(tok, "fu:", 3))
 582                                         fu = tok + 3;
 583                                 else if (!strncmp(tok, "fh:", 3)) {
 584                                         if (!strncasecmp(tok+3, vpninfo->xmlsha1,
 585                                                          SHA_DIGEST_LENGTH * 2))
 586                                                 break;
 587                                         sha = tok + 3;
 588                                 }
 589                         } while ((tok = strchr(tok, '&')));
 590
 591                         if (bu && fu && sha)
 592                                 fetch_config(vpninfo, bu, fu, sha);
 593                 }
 594         }
 595         if (vpninfo->csd_scriptname) {
 596                 unlink(vpninfo->csd_scriptname);
 597                 free(vpninfo->csd_scriptname);
 598                 vpninfo->csd_scriptname = NULL;
 599         }
 600         return 0;
 601 }
 602
 603 char *openconnect_create_useragent(char *base)
 604 {
 605         char *uagent = malloc(strlen(base) + 1 + strlen(openconnect_version));
 606         sprintf(uagent, "%s %s", base, openconnect_version);
 607         return uagent;
 608 }