client/cifs.upcall.c

   1 /*
   2 * CIFS user-space helper.
   3 * Copyright (C) Igor Mammedov (niallain@gmail.com) 2007
   4 * Copyright (C) Jeff Layton (jlayton@redhat.com) 2009
   5 *
   6 * Used by /sbin/request-key for handling
   7 * cifs upcall for kerberos authorization of access to share and
   8 * cifs upcall for DFS srver name resolving (IPv4/IPv6 aware).
   9 * You should have keyutils installed and add something like the
  10 * following lines to /etc/request-key.conf file:
  11
  12 create cifs.spnego * * /usr/local/sbin/cifs.upcall %k
  13 create dns_resolver * * /usr/local/sbin/cifs.upcall %k
  14
  15 * This program is free software; you can redistribute it and/or modify
  16 * it under the terms of the GNU General Public License as published by
  17 * the Free Software Foundation; either version 2 of the License, or
  18 * (at your option) any later version.
  19 * This program is distributed in the hope that it will be useful,
  20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  22 * GNU General Public License for more details.
  23 * You should have received a copy of the GNU General Public License
  24 * along with this program; if not, write to the Free Software
  25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  26 */
  27
  28 #include "includes.h"
  29 #include "../libcli/auth/spnego.h"
  30 #include "smb_krb5.h"
  31 #include <keyutils.h>
  32 #include <getopt.h>
  33
  34 #include "cifs_spnego.h"
  35
  36 #define CIFS_DEFAULT_KRB5_DIR           "/tmp"
  37 #define CIFS_DEFAULT_KRB5_PREFIX        "krb5cc_"
  38
  39 #define MAX_CCNAME_LEN                  PATH_MAX + 5
  40
  41 const char *CIFSSPNEGO_VERSION = "1.3";
  42 static const char *prog = "cifs.upcall";
  43 typedef enum _sectype {
  44         NONE = 0,
  45         KRB5,
  46         MS_KRB5
  47 } sectype_t;
  48
  49 /* does the ccache have a valid TGT? */
  50 static time_t
  51 get_tgt_time(const char *ccname) {
  52         krb5_context context;
  53         krb5_ccache ccache;
  54         krb5_cc_cursor cur;
  55         krb5_creds creds;
  56         krb5_principal principal;
  57         time_t credtime = 0;
  58         char *realm = NULL;
  59         TALLOC_CTX *mem_ctx;
  60
  61         if (krb5_init_context(&context)) {
  62                 syslog(LOG_DEBUG, "%s: unable to init krb5 context", __func__);
  63                 return 0;
  64         }
  65
  66         if (krb5_cc_resolve(context, ccname, &ccache)) {
  67                 syslog(LOG_DEBUG, "%s: unable to resolve krb5 cache", __func__);
  68                 goto err_cache;
  69         }
  70
  71         if (krb5_cc_set_flags(context, ccache, 0)) {
  72                 syslog(LOG_DEBUG, "%s: unable to set flags", __func__);
  73                 goto err_cache;
  74         }
  75
  76         if (krb5_cc_get_principal(context, ccache, &principal)) {
  77                 syslog(LOG_DEBUG, "%s: unable to get principal", __func__);
  78                 goto err_princ;
  79         }
  80
  81         if (krb5_cc_start_seq_get(context, ccache, &cur)) {
  82                 syslog(LOG_DEBUG, "%s: unable to seq start", __func__);
  83                 goto err_ccstart;
  84         }
  85
  86         if ((realm = smb_krb5_principal_get_realm(context, principal)) == NULL) {
  87                 syslog(LOG_DEBUG, "%s: unable to get realm", __func__);
  88                 goto err_ccstart;
  89         }
  90
  91         mem_ctx = talloc_init("cifs.upcall");
  92         while (!credtime && !krb5_cc_next_cred(context, ccache, &cur, &creds)) {
  93                 char *name;
  94                 if (smb_krb5_unparse_name(mem_ctx, context, creds.server, &name)) {
  95                         syslog(LOG_DEBUG, "%s: unable to unparse name", __func__);
  96                         goto err_endseq;
  97                 }
  98                 if (krb5_realm_compare(context, creds.server, principal) &&
  99                     strnequal(name, KRB5_TGS_NAME, KRB5_TGS_NAME_SIZE) &&
 100                     strnequal(name+KRB5_TGS_NAME_SIZE+1, realm, strlen(realm)) &&
 101                     creds.times.endtime > time(NULL))
 102                         credtime = creds.times.endtime;
 103                 krb5_free_cred_contents(context, &creds);
 104                 TALLOC_FREE(name);
 105         }
 106 err_endseq:
 107         TALLOC_FREE(mem_ctx);
 108         krb5_cc_end_seq_get(context, ccache, &cur);
 109 err_ccstart:
 110         krb5_free_principal(context, principal);
 111 err_princ:
 112 #if defined(KRB5_TC_OPENCLOSE)
 113         krb5_cc_set_flags(context, ccache, KRB5_TC_OPENCLOSE);
 114 #endif
 115         krb5_cc_close(context, ccache);
 116 err_cache:
 117         krb5_free_context(context);
 118         return credtime;
 119 }
 120
 121 static int
 122 krb5cc_filter(const struct dirent *dirent)
 123 {
 124         if (strstr(dirent->d_name, CIFS_DEFAULT_KRB5_PREFIX))
 125                 return 1;
 126         else
 127                 return 0;
 128 }
 129
 130 /* search for a credcache that looks like a likely candidate */
 131 static char *
 132 find_krb5_cc(const char *dirname, uid_t uid)
 133 {
 134         struct dirent **namelist;
 135         struct stat sbuf;
 136         char ccname[MAX_CCNAME_LEN], *credpath, *best_cache = NULL;
 137         int i, n;
 138         time_t cred_time, best_time = 0;
 139
 140         n = scandir(dirname, &namelist, krb5cc_filter, NULL);
 141         if (n < 0) {
 142                 syslog(LOG_DEBUG, "%s: scandir error on directory '%s': %s",
 143                                   __func__, dirname, strerror(errno));
 144                 return NULL;
 145         }
 146
 147         for (i = 0; i < n; i++) {
 148                 snprintf(ccname, sizeof(ccname), "FILE:%s/%s", dirname,
 149                          namelist[i]->d_name);
 150                 credpath = ccname + 5;
 151                 syslog(LOG_DEBUG, "%s: considering %s", __func__, credpath);
 152
 153                 if (lstat(credpath, &sbuf)) {
 154                         syslog(LOG_DEBUG, "%s: stat error on '%s': %s",
 155                                           __func__, credpath, strerror(errno));
 156                         free(namelist[i]);
 157                         continue;
 158                 }
 159                 if (sbuf.st_uid != uid) {
 160                         syslog(LOG_DEBUG, "%s: %s is owned by %u, not %u",
 161                                         __func__, credpath, sbuf.st_uid, uid);
 162                         free(namelist[i]);
 163                         continue;
 164                 }
 165                 if (!S_ISREG(sbuf.st_mode)) {
 166                         syslog(LOG_DEBUG, "%s: %s is not a regular file",
 167                                         __func__, credpath);
 168                         free(namelist[i]);
 169                         continue;
 170                 }
 171                 if (!(cred_time = get_tgt_time(ccname))) {
 172                         syslog(LOG_DEBUG, "%s: %s is not a valid credcache.",
 173                                         __func__, ccname);
 174                         free(namelist[i]);
 175                         continue;
 176                 }
 177
 178                 if (cred_time <= best_time) {
 179                         syslog(LOG_DEBUG, "%s: %s expires sooner than current "
 180                                           "best.", __func__, ccname);
 181                         free(namelist[i]);
 182                         continue;
 183                 }
 184
 185                 syslog(LOG_DEBUG, "%s: %s is valid ccache", __func__, ccname);
 186                 free(best_cache);
 187                 best_cache = SMB_STRNDUP(ccname, MAX_CCNAME_LEN);
 188                 best_time = cred_time;
 189                 free(namelist[i]);
 190         }
 191         free(namelist);
 192
 193         return best_cache;
 194 }
 195
 196 /*
 197  * Prepares AP-REQ data for mechToken and gets session key
 198  * Uses credentials from cache. It will not ask for password
 199  * you should receive credentials for yuor name manually using
 200  * kinit or whatever you wish.
 201  *
 202  * in:
 203  *      oid -           string with OID/ Could be OID_KERBEROS5
 204  *                      or OID_KERBEROS5_OLD
 205  *      principal -     Service name.
 206  *                      Could be "cifs/FQDN" for KRB5 OID
 207  *                      or for MS_KRB5 OID style server principal
 208  *                      like "pdc$@YOUR.REALM.NAME"
 209  *
 210  * out:
 211  *      secblob -       pointer for spnego wrapped AP-REQ data to be stored
 212  *      sess_key-       pointer for SessionKey data to be stored
 213  *
 214  * ret: 0 - success, others - failure
 215  */
 216 static int
 217 handle_krb5_mech(const char *oid, const char *principal, DATA_BLOB *secblob,
 218                  DATA_BLOB *sess_key, const char *ccname)
 219 {
 220         int retval;
 221         DATA_BLOB tkt, tkt_wrapped;
 222
 223         syslog(LOG_DEBUG, "%s: getting service ticket for %s", __func__,
 224                           principal);
 225
 226         /* get a kerberos ticket for the service and extract the session key */
 227         retval = cli_krb5_get_ticket(principal, 0, &tkt, sess_key, 0, ccname,
 228                                      NULL, NULL);
 229
 230         if (retval) {
 231                 syslog(LOG_DEBUG, "%s: failed to obtain service ticket (%d)",
 232                                   __func__, retval);
 233                 return retval;
 234         }
 235
 236         syslog(LOG_DEBUG, "%s: obtained service ticket", __func__);
 237
 238         /* wrap that up in a nice GSS-API wrapping */
 239         tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
 240
 241         /* and wrap that in a shiny SPNEGO wrapper */
 242         *secblob = gen_negTokenInit(oid, tkt_wrapped);
 243
 244         data_blob_free(&tkt_wrapped);
 245         data_blob_free(&tkt);
 246         return retval;
 247 }
 248
 249 #define DKD_HAVE_HOSTNAME       0x1
 250 #define DKD_HAVE_VERSION        0x2
 251 #define DKD_HAVE_SEC            0x4
 252 #define DKD_HAVE_IP             0x8
 253 #define DKD_HAVE_UID            0x10
 254 #define DKD_HAVE_PID            0x20
 255 #define DKD_MUSTHAVE_SET (DKD_HAVE_HOSTNAME|DKD_HAVE_VERSION|DKD_HAVE_SEC)
 256
 257 struct decoded_args {
 258         int             ver;
 259         char            *hostname;
 260         char            *ip;
 261         uid_t           uid;
 262         pid_t           pid;
 263         sectype_t       sec;
 264 };
 265
 266 static unsigned int
 267 decode_key_description(const char *desc, struct decoded_args *arg)
 268 {
 269         int len;
 270         int retval = 0;
 271         char *pos;
 272         const char *tkn = desc;
 273
 274         do {
 275                 pos = index(tkn, ';');
 276                 if (strncmp(tkn, "host=", 5) == 0) {
 277
 278                         if (pos == NULL)
 279                                 len = strlen(tkn);
 280                         else
 281                                 len = pos - tkn;
 282
 283                         len -= 4;
 284                         SAFE_FREE(arg->hostname);
 285                         arg->hostname = SMB_XMALLOC_ARRAY(char, len);
 286                         strlcpy(arg->hostname, tkn + 5, len);
 287                         retval |= DKD_HAVE_HOSTNAME;
 288                 } else if (!strncmp(tkn, "ip4=", 4) ||
 289                            !strncmp(tkn, "ip6=", 4)) {
 290                         if (pos == NULL)
 291                                 len = strlen(tkn);
 292                         else
 293                                 len = pos - tkn;
 294
 295                         len -= 3;
 296                         SAFE_FREE(arg->ip);
 297                         arg->ip = SMB_XMALLOC_ARRAY(char, len);
 298                         strlcpy(arg->ip, tkn + 4, len);
 299                         retval |= DKD_HAVE_IP;
 300                 } else if (strncmp(tkn, "pid=", 4) == 0) {
 301                         errno = 0;
 302                         arg->pid = strtol(tkn + 4, NULL, 0);
 303                         if (errno != 0) {
 304                                 syslog(LOG_ERR, "Invalid pid format: %s",
 305                                        strerror(errno));
 306                                 return 1;
 307                         } else {
 308                                 retval |= DKD_HAVE_PID;
 309                         }
 310                 } else if (strncmp(tkn, "sec=", 4) == 0) {
 311                         if (strncmp(tkn + 4, "krb5", 4) == 0) {
 312                                 retval |= DKD_HAVE_SEC;
 313                                 arg->sec = KRB5;
 314                         } else if (strncmp(tkn + 4, "mskrb5", 6) == 0) {
 315                                 retval |= DKD_HAVE_SEC;
 316                                 arg->sec = MS_KRB5;
 317                         }
 318                 } else if (strncmp(tkn, "uid=", 4) == 0) {
 319                         errno = 0;
 320                         arg->uid = strtol(tkn + 4, NULL, 16);
 321                         if (errno != 0) {
 322                                 syslog(LOG_ERR, "Invalid uid format: %s",
 323                                        strerror(errno));
 324                                 return 1;
 325                         } else {
 326                                 retval |= DKD_HAVE_UID;
 327                         }
 328                 } else if (strncmp(tkn, "ver=", 4) == 0) {      /* if version */
 329                         errno = 0;
 330                         arg->ver = strtol(tkn + 4, NULL, 16);
 331                         if (errno != 0) {
 332                                 syslog(LOG_ERR, "Invalid version format: %s",
 333                                        strerror(errno));
 334                                 return 1;
 335                         } else {
 336                                 retval |= DKD_HAVE_VERSION;
 337                         }
 338                 }
 339                 if (pos == NULL)
 340                         break;
 341                 tkn = pos + 1;
 342         } while (tkn);
 343         return retval;
 344 }
 345
 346 static int
 347 cifs_resolver(const key_serial_t key, const char *key_descr)
 348 {
 349         int c;
 350         struct addrinfo *addr;
 351         char ip[INET6_ADDRSTRLEN];
 352         void *p;
 353         const char *keyend = key_descr;
 354         /* skip next 4 ';' delimiters to get to description */
 355         for (c = 1; c <= 4; c++) {
 356                 keyend = index(keyend+1, ';');
 357                 if (!keyend) {
 358                         syslog(LOG_ERR, "invalid key description: %s",
 359                                         key_descr);
 360                         return 1;
 361                 }
 362         }
 363         keyend++;
 364
 365         /* resolve name to ip */
 366         c = getaddrinfo(keyend, NULL, NULL, &addr);
 367         if (c) {
 368                 syslog(LOG_ERR, "unable to resolve hostname: %s [%s]",
 369                                 keyend, gai_strerror(c));
 370                 return 1;
 371         }
 372
 373         /* conver ip to string form */
 374         if (addr->ai_family == AF_INET)
 375                 p = &(((struct sockaddr_in *)addr->ai_addr)->sin_addr);
 376         else
 377                 p = &(((struct sockaddr_in6 *)addr->ai_addr)->sin6_addr);
 378
 379         if (!inet_ntop(addr->ai_family, p, ip, sizeof(ip))) {
 380                 syslog(LOG_ERR, "%s: inet_ntop: %s", __func__, strerror(errno));
 381                 freeaddrinfo(addr);
 382                 return 1;
 383         }
 384
 385         /* setup key */
 386         c = keyctl_instantiate(key, ip, strlen(ip)+1, 0);
 387         if (c == -1) {
 388                 syslog(LOG_ERR, "%s: keyctl_instantiate: %s", __func__,
 389                                 strerror(errno));
 390                 freeaddrinfo(addr);
 391                 return 1;
 392         }
 393
 394         freeaddrinfo(addr);
 395         return 0;
 396 }
 397
 398 /*
 399  * Older kernels sent IPv6 addresses without colons. Well, at least
 400  * they're fixed-length strings. Convert these addresses to have colon
 401  * delimiters to make getaddrinfo happy.
 402  */
 403 static void
 404 convert_inet6_addr(const char *from, char *to)
 405 {
 406         int i = 1;
 407
 408         while (*from) {
 409                 *to++ = *from++;
 410                 if (!(i++ % 4) && *from)
 411                         *to++ = ':';
 412         }
 413         *to = 0;
 414 }
 415
 416 static int
 417 ip_to_fqdn(const char *addrstr, char *host, size_t hostlen)
 418 {
 419         int rc;
 420         struct addrinfo hints = { .ai_flags = AI_NUMERICHOST };
 421         struct addrinfo *res;
 422         const char *ipaddr = addrstr;
 423         char converted[INET6_ADDRSTRLEN + 1];
 424
 425         if ((strlen(ipaddr) > INET_ADDRSTRLEN) && !strchr(ipaddr, ':')) {
 426                 convert_inet6_addr(ipaddr, converted);
 427                 ipaddr = converted;
 428         }
 429
 430         rc = getaddrinfo(ipaddr, NULL, &hints, &res);
 431         if (rc) {
 432                 syslog(LOG_DEBUG, "%s: failed to resolve %s to "
 433                         "ipaddr: %s", __func__, ipaddr,
 434                 rc == EAI_SYSTEM ? strerror(errno) : gai_strerror(rc));
 435                 return rc;
 436         }
 437
 438         rc = getnameinfo(res->ai_addr, res->ai_addrlen, host, hostlen,
 439                          NULL, 0, NI_NAMEREQD);
 440         freeaddrinfo(res);
 441         if (rc) {
 442                 syslog(LOG_DEBUG, "%s: failed to resolve %s to fqdn: %s",
 443                         __func__, ipaddr,
 444                         rc == EAI_SYSTEM ? strerror(errno) : gai_strerror(rc));
 445                 return rc;
 446         }
 447
 448         syslog(LOG_DEBUG, "%s: resolved %s to %s", __func__, ipaddr, host);
 449         return 0;
 450 }
 451
 452 static void
 453 usage(void)
 454 {
 455         syslog(LOG_INFO, "Usage: %s [-t] [-v] key_serial", prog);
 456         fprintf(stderr, "Usage: %s [-t] [-v] key_serial\n", prog);
 457 }
 458
 459 const struct option long_options[] = {
 460         { "trust-dns",  0, NULL, 't' },
 461         { "version",    0, NULL, 'v' },
 462         { NULL,         0, NULL, 0 }
 463 };
 464
 465 int main(const int argc, char *const argv[])
 466 {
 467         struct cifs_spnego_msg *keydata = NULL;
 468         DATA_BLOB secblob = data_blob_null;
 469         DATA_BLOB sess_key = data_blob_null;
 470         key_serial_t key = 0;
 471         size_t datalen;
 472         unsigned int have;
 473         long rc = 1;
 474         int c, try_dns = 0;
 475         char *buf, *princ = NULL, *ccname = NULL;
 476         char hostbuf[NI_MAXHOST], *host;
 477         struct decoded_args arg = { };
 478         const char *oid;
 479
 480         hostbuf[0] = '\0';
 481
 482         openlog(prog, 0, LOG_DAEMON);
 483
 484         while ((c = getopt_long(argc, argv, "ctv", long_options, NULL)) != -1) {
 485                 switch (c) {
 486                 case 'c':
 487                         /* legacy option -- skip it */
 488                         break;
 489                 case 't':
 490                         try_dns++;
 491                         break;
 492                 case 'v':
 493                         printf("version: %s\n", CIFSSPNEGO_VERSION);
 494                         goto out;
 495                 default:
 496                         syslog(LOG_ERR, "unknown option: %c", c);
 497                         goto out;
 498                 }
 499         }
 500
 501         /* is there a key? */
 502         if (argc <= optind) {
 503                 usage();
 504                 goto out;
 505         }
 506
 507         /* get key and keyring values */
 508         errno = 0;
 509         key = strtol(argv[optind], NULL, 10);
 510         if (errno != 0) {
 511                 key = 0;
 512                 syslog(LOG_ERR, "Invalid key format: %s", strerror(errno));
 513                 goto out;
 514         }
 515
 516         rc = keyctl_describe_alloc(key, &buf);
 517         if (rc == -1) {
 518                 syslog(LOG_ERR, "keyctl_describe_alloc failed: %s",
 519                        strerror(errno));
 520                 rc = 1;
 521                 goto out;
 522         }
 523
 524         syslog(LOG_DEBUG, "key description: %s", buf);
 525
 526         if ((strncmp(buf, "cifs.resolver", sizeof("cifs.resolver")-1) == 0) ||
 527             (strncmp(buf, "dns_resolver", sizeof("dns_resolver")-1) == 0)) {
 528                 rc = cifs_resolver(key, buf);
 529                 goto out;
 530         }
 531
 532         have = decode_key_description(buf, &arg);
 533         SAFE_FREE(buf);
 534         if ((have & DKD_MUSTHAVE_SET) != DKD_MUSTHAVE_SET) {
 535                 syslog(LOG_ERR, "unable to get necessary params from key "
 536                                 "description (0x%x)", have);
 537                 rc = 1;
 538                 goto out;
 539         }
 540
 541         if (arg.ver > CIFS_SPNEGO_UPCALL_VERSION) {
 542                 syslog(LOG_ERR, "incompatible kernel upcall version: 0x%x",
 543                                 arg.ver);
 544                 rc = 1;
 545                 goto out;
 546         }
 547
 548         if (have & DKD_HAVE_UID) {
 549                 rc = setuid(arg.uid);
 550                 if (rc == -1) {
 551                         syslog(LOG_ERR, "setuid: %s", strerror(errno));
 552                         goto out;
 553                 }
 554
 555                 ccname = find_krb5_cc(CIFS_DEFAULT_KRB5_DIR, arg.uid);
 556         }
 557
 558         host = arg.hostname;
 559
 560         // do mech specific authorization
 561         switch (arg.sec) {
 562         case MS_KRB5:
 563         case KRB5:
 564 retry_new_hostname:
 565                 /* for "cifs/" service name + terminating 0 */
 566                 datalen = strlen(host) + 5 + 1;
 567                 princ = SMB_XMALLOC_ARRAY(char, datalen);
 568                 if (!princ) {
 569                         rc = -ENOMEM;
 570                         break;
 571                 }
 572
 573                 if (arg.sec == MS_KRB5)
 574                         oid = OID_KERBEROS5_OLD;
 575                 else
 576                         oid = OID_KERBEROS5;
 577
 578                 /*
 579                  * try getting a cifs/ principal first and then fall back to
 580                  * getting a host/ principal if that doesn't work.
 581                  */
 582                 strlcpy(princ, "cifs/", datalen);
 583                 strlcpy(princ + 5, host, datalen - 5);
 584                 rc = handle_krb5_mech(oid, princ, &secblob, &sess_key, ccname);
 585                 if (!rc)
 586                         break;
 587
 588                 memcpy(princ, "host/", 5);
 589                 rc = handle_krb5_mech(oid, princ, &secblob, &sess_key, ccname);
 590                 if (!rc)
 591                         break;
 592
 593                 if (!try_dns || !(have & DKD_HAVE_IP))
 594                         break;
 595
 596                 rc = ip_to_fqdn(arg.ip, hostbuf, sizeof(hostbuf));
 597                 if (rc)
 598                         break;
 599
 600                 SAFE_FREE(princ);
 601                 try_dns = 0;
 602                 host = hostbuf;
 603                 goto retry_new_hostname;
 604         default:
 605                 syslog(LOG_ERR, "sectype: %d is not implemented", arg.sec);
 606                 rc = 1;
 607                 break;
 608         }
 609
 610         SAFE_FREE(princ);
 611
 612         if (rc)
 613                 goto out;
 614
 615         /* pack SecurityBLob and SessionKey into downcall packet */
 616         datalen =
 617             sizeof(struct cifs_spnego_msg) + secblob.length + sess_key.length;
 618         keydata = (struct cifs_spnego_msg*)SMB_XMALLOC_ARRAY(char, datalen);
 619         if (!keydata) {
 620                 rc = 1;
 621                 goto out;
 622         }
 623         keydata->version = arg.ver;
 624         keydata->flags = 0;
 625         keydata->sesskey_len = sess_key.length;
 626         keydata->secblob_len = secblob.length;
 627         memcpy(&(keydata->data), sess_key.data, sess_key.length);
 628         memcpy(&(keydata->data) + keydata->sesskey_len,
 629                secblob.data, secblob.length);
 630
 631         /* setup key */
 632         rc = keyctl_instantiate(key, keydata, datalen, 0);
 633         if (rc == -1) {
 634                 syslog(LOG_ERR, "keyctl_instantiate: %s", strerror(errno));
 635                 goto out;
 636         }
 637
 638         /* BB: maybe we need use timeout for key: for example no more then
 639          * ticket lifietime? */
 640         /* keyctl_set_timeout( key, 60); */
 641 out:
 642         /*
 643          * on error, negatively instantiate the key ourselves so that we can
 644          * make sure the kernel doesn't hang it off of a searchable keyring
 645          * and interfere with the next attempt to instantiate the key.
 646          */
 647         if (rc != 0  && key == 0)
 648                 keyctl_negate(key, 1, KEY_REQKEY_DEFL_DEFAULT);
 649         data_blob_free(&secblob);
 650         data_blob_free(&sess_key);
 651         SAFE_FREE(ccname);
 652         SAFE_FREE(arg.hostname);
 653         SAFE_FREE(arg.ip);
 654         SAFE_FREE(keydata);
 655         return rc;
 656 }