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