lib/krb5/fcache.c

   1 /*
   2  * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "krb5_locl.h"
  37
  38 typedef struct krb5_fcache{
  39     char *filename;
  40     int version;
  41 }krb5_fcache;
  42
  43 struct fcc_cursor {
  44     int fd;
  45     krb5_storage *sp;
  46 };
  47
  48 #define KRB5_FCC_FVNO_1 1
  49 #define KRB5_FCC_FVNO_2 2
  50 #define KRB5_FCC_FVNO_3 3
  51 #define KRB5_FCC_FVNO_4 4
  52
  53 #define FCC_TAG_DELTATIME 1
  54
  55 #define FCACHE(X) ((krb5_fcache*)(X)->data.data)
  56
  57 #define FILENAME(X) (FCACHE(X)->filename)
  58
  59 #define FCC_CURSOR(C) ((struct fcc_cursor*)(C))
  60
  61 static const char* KRB5_CALLCONV
  62 fcc_get_name(krb5_context context,
  63              krb5_ccache id)
  64 {
  65     if (FCACHE(id) == NULL)
  66         return NULL;
  67
  68     return FILENAME(id);
  69 }
  70
  71 int
  72 _krb5_xlock(krb5_context context, int fd, krb5_boolean exclusive,
  73             const char *filename)
  74 {
  75     int ret;
  76 #ifdef HAVE_FCNTL
  77     struct flock l;
  78
  79     l.l_start = 0;
  80     l.l_len = 0;
  81     l.l_type = exclusive ? F_WRLCK : F_RDLCK;
  82     l.l_whence = SEEK_SET;
  83     ret = fcntl(fd, F_SETLKW, &l);
  84 #else
  85     ret = flock(fd, exclusive ? LOCK_EX : LOCK_SH);
  86 #endif
  87     if(ret < 0)
  88         ret = errno;
  89     if(ret == EACCES) /* fcntl can return EACCES instead of EAGAIN */
  90         ret = EAGAIN;
  91
  92     switch (ret) {
  93     case 0:
  94         break;
  95     case EINVAL: /* filesystem doesn't support locking, let the user have it */
  96         ret = 0;
  97         break;
  98     case EAGAIN:
  99         krb5_set_error_message(context, ret,
 100                                N_("timed out locking cache file %s", "file"),
 101                                filename);
 102         break;
 103     default: {
 104         char buf[128];
 105         rk_strerror_r(ret, buf, sizeof(buf));
 106         krb5_set_error_message(context, ret,
 107                                N_("error locking cache file %s: %s",
 108                                   "file, error"), filename, buf);
 109         break;
 110     }
 111     }
 112     return ret;
 113 }
 114
 115 int
 116 _krb5_xunlock(krb5_context context, int fd)
 117 {
 118     int ret;
 119 #ifdef HAVE_FCNTL
 120     struct flock l;
 121     l.l_start = 0;
 122     l.l_len = 0;
 123     l.l_type = F_UNLCK;
 124     l.l_whence = SEEK_SET;
 125     ret = fcntl(fd, F_SETLKW, &l);
 126 #else
 127     ret = flock(fd, LOCK_UN);
 128 #endif
 129     if (ret < 0)
 130         ret = errno;
 131     switch (ret) {
 132     case 0:
 133         break;
 134     case EINVAL: /* filesystem doesn't support locking, let the user have it */
 135         ret = 0;
 136         break;
 137     default: {
 138         char buf[128];
 139         rk_strerror_r(ret, buf, sizeof(buf));
 140         krb5_set_error_message(context, ret,
 141                                N_("Failed to unlock file: %s", ""), buf);
 142         break;
 143     }
 144     }
 145     return ret;
 146 }
 147
 148 static krb5_error_code
 149 write_storage(krb5_context context, krb5_storage *sp, int fd)
 150 {
 151     krb5_error_code ret;
 152     krb5_data data;
 153     ssize_t sret;
 154
 155     ret = krb5_storage_to_data(sp, &data);
 156     if (ret) {
 157         krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
 158         return ret;
 159     }
 160     sret = write(fd, data.data, data.length);
 161     ret = (sret != (ssize_t)data.length);
 162     krb5_data_free(&data);
 163     if (ret) {
 164         ret = errno;
 165         krb5_set_error_message(context, ret,
 166                                N_("Failed to write FILE credential data", ""));
 167         return ret;
 168     }
 169     return 0;
 170 }
 171
 172
 173 static krb5_error_code KRB5_CALLCONV
 174 fcc_lock(krb5_context context, krb5_ccache id,
 175          int fd, krb5_boolean exclusive)
 176 {
 177     return _krb5_xlock(context, fd, exclusive, fcc_get_name(context, id));
 178 }
 179
 180 static krb5_error_code KRB5_CALLCONV
 181 fcc_unlock(krb5_context context, int fd)
 182 {
 183     return _krb5_xunlock(context, fd);
 184 }
 185
 186 static krb5_error_code KRB5_CALLCONV
 187 fcc_resolve(krb5_context context, krb5_ccache *id, const char *res)
 188 {
 189     krb5_fcache *f;
 190     f = malloc(sizeof(*f));
 191     if(f == NULL) {
 192         krb5_set_error_message(context, KRB5_CC_NOMEM,
 193                                N_("malloc: out of memory", ""));
 194         return KRB5_CC_NOMEM;
 195     }
 196     f->filename = strdup(res);
 197     if(f->filename == NULL){
 198         free(f);
 199         krb5_set_error_message(context, KRB5_CC_NOMEM,
 200                                N_("malloc: out of memory", ""));
 201         return KRB5_CC_NOMEM;
 202     }
 203     f->version = 0;
 204     (*id)->data.data = f;
 205     (*id)->data.length = sizeof(*f);
 206     return 0;
 207 }
 208
 209 /*
 210  * Try to scrub the contents of `filename' safely.
 211  */
 212
 213 static int
 214 scrub_file (int fd)
 215 {
 216     off_t pos;
 217     char buf[128];
 218
 219     pos = lseek(fd, 0, SEEK_END);
 220     if (pos < 0)
 221         return errno;
 222     if (lseek(fd, 0, SEEK_SET) < 0)
 223         return errno;
 224     memset(buf, 0, sizeof(buf));
 225     while(pos > 0) {
 226         ssize_t tmp = write(fd, buf, min((off_t)sizeof(buf), pos));
 227
 228         if (tmp < 0)
 229             return errno;
 230         pos -= tmp;
 231     }
 232 #ifdef _MSC_VER
 233     _commit (fd);
 234 #else
 235     fsync (fd);
 236 #endif
 237     return 0;
 238 }
 239
 240 /*
 241  * Erase `filename' if it exists, trying to remove the contents if
 242  * it's `safe'.  We always try to remove the file, it it exists.  It's
 243  * only overwritten if it's a regular file (not a symlink and not a
 244  * hardlink)
 245  */
 246
 247 krb5_error_code
 248 _krb5_erase_file(krb5_context context, const char *filename)
 249 {
 250     int fd;
 251     struct stat sb1, sb2;
 252     int ret;
 253
 254     ret = lstat (filename, &sb1);
 255     if (ret < 0)
 256         return errno;
 257
 258     fd = open(filename, O_RDWR | O_BINARY);
 259     if(fd < 0) {
 260         if(errno == ENOENT)
 261             return 0;
 262         else
 263             return errno;
 264     }
 265     rk_cloexec(fd);
 266     ret = _krb5_xlock(context, fd, 1, filename);
 267     if (ret) {
 268         close(fd);
 269         return ret;
 270     }
 271     if (unlink(filename) < 0) {
 272         _krb5_xunlock(context, fd);
 273         close (fd);
 274         return errno;
 275     }
 276     ret = fstat (fd, &sb2);
 277     if (ret < 0) {
 278         _krb5_xunlock(context, fd);
 279         close (fd);
 280         return errno;
 281     }
 282
 283     /* check if someone was playing with symlinks */
 284
 285     if (sb1.st_dev != sb2.st_dev || sb1.st_ino != sb2.st_ino) {
 286         _krb5_xunlock(context, fd);
 287         close (fd);
 288         return EPERM;
 289     }
 290
 291     /* there are still hard links to this file */
 292
 293     if (sb2.st_nlink != 0) {
 294         _krb5_xunlock(context, fd);
 295         close (fd);
 296         return 0;
 297     }
 298
 299     ret = scrub_file (fd);
 300     if (ret) {
 301         _krb5_xunlock(context, fd);
 302         close(fd);
 303         return ret;
 304     }
 305     ret = _krb5_xunlock(context, fd);
 306     close (fd);
 307     return ret;
 308 }
 309
 310 static krb5_error_code KRB5_CALLCONV
 311 fcc_gen_new(krb5_context context, krb5_ccache *id)
 312 {
 313     char *file = NULL, *exp_file = NULL;
 314     krb5_error_code ret;
 315     krb5_fcache *f;
 316     int fd;
 317
 318     f = malloc(sizeof(*f));
 319     if(f == NULL) {
 320         krb5_set_error_message(context, KRB5_CC_NOMEM,
 321                                N_("malloc: out of memory", ""));
 322         return KRB5_CC_NOMEM;
 323     }
 324     ret = asprintf (&file, "%sXXXXXX", KRB5_DEFAULT_CCFILE_ROOT);
 325     if(ret < 0 || file == NULL) {
 326         free(f);
 327         krb5_set_error_message(context, KRB5_CC_NOMEM,
 328                                N_("malloc: out of memory", ""));
 329         return KRB5_CC_NOMEM;
 330     }
 331     ret = _krb5_expand_path_tokens(context, file, &exp_file);
 332     free(file);
 333     if (ret)
 334         return ret;
 335
 336     file = exp_file;
 337
 338     fd = mkstemp(exp_file);
 339     if(fd < 0) {
 340         int xret = errno;
 341         krb5_set_error_message(context, xret, N_("mkstemp %s failed", ""), exp_file);
 342         free(f);
 343         free(exp_file);
 344         return xret;
 345     }
 346     close(fd);
 347     f->filename = exp_file;
 348     f->version = 0;
 349     (*id)->data.data = f;
 350     (*id)->data.length = sizeof(*f);
 351     return 0;
 352 }
 353
 354 static void
 355 storage_set_flags(krb5_context context, krb5_storage *sp, int vno)
 356 {
 357     int flags = 0;
 358     switch(vno) {
 359     case KRB5_FCC_FVNO_1:
 360         flags |= KRB5_STORAGE_PRINCIPAL_WRONG_NUM_COMPONENTS;
 361         flags |= KRB5_STORAGE_PRINCIPAL_NO_NAME_TYPE;
 362         flags |= KRB5_STORAGE_HOST_BYTEORDER;
 363         break;
 364     case KRB5_FCC_FVNO_2:
 365         flags |= KRB5_STORAGE_HOST_BYTEORDER;
 366         break;
 367     case KRB5_FCC_FVNO_3:
 368         flags |= KRB5_STORAGE_KEYBLOCK_KEYTYPE_TWICE;
 369         break;
 370     case KRB5_FCC_FVNO_4:
 371         break;
 372     default:
 373         krb5_abortx(context,
 374                     "storage_set_flags called with bad vno (%x)", vno);
 375     }
 376     krb5_storage_set_flags(sp, flags);
 377 }
 378
 379 static krb5_error_code KRB5_CALLCONV
 380 fcc_open(krb5_context context,
 381          krb5_ccache id,
 382          int *fd_ret,
 383          int flags,
 384          mode_t mode)
 385 {
 386     krb5_boolean exclusive = ((flags | O_WRONLY) == flags ||
 387                               (flags | O_RDWR) == flags);
 388     krb5_error_code ret;
 389     const char *filename;
 390     int fd;
 391
 392     if (FCACHE(id) == NULL)
 393         return krb5_einval(context, 2);
 394
 395     filename = FILENAME(id);
 396
 397     fd = open(filename, flags, mode);
 398     if(fd < 0) {
 399         char buf[128];
 400         ret = errno;
 401         rk_strerror_r(ret, buf, sizeof(buf));
 402         krb5_set_error_message(context, ret, N_("open(%s): %s", "file, error"),
 403                                filename, buf);
 404         return ret;
 405     }
 406     rk_cloexec(fd);
 407
 408     if((ret = fcc_lock(context, id, fd, exclusive)) != 0) {
 409         close(fd);
 410         return ret;
 411     }
 412     *fd_ret = fd;
 413     return 0;
 414 }
 415
 416 static krb5_error_code KRB5_CALLCONV
 417 fcc_initialize(krb5_context context,
 418                krb5_ccache id,
 419                krb5_principal primary_principal)
 420 {
 421     krb5_fcache *f = FCACHE(id);
 422     int ret = 0;
 423     int fd;
 424
 425     if (f == NULL)
 426         return krb5_einval(context, 2);
 427
 428     unlink (f->filename);
 429
 430     ret = fcc_open(context, id, &fd, O_RDWR | O_CREAT | O_EXCL | O_BINARY | O_CLOEXEC, 0600);
 431     if(ret)
 432         return ret;
 433     {
 434         krb5_storage *sp;
 435         sp = krb5_storage_emem();
 436         krb5_storage_set_eof_code(sp, KRB5_CC_END);
 437         if(context->fcache_vno != 0)
 438             f->version = context->fcache_vno;
 439         else
 440             f->version = KRB5_FCC_FVNO_4;
 441         ret |= krb5_store_int8(sp, 5);
 442         ret |= krb5_store_int8(sp, f->version);
 443         storage_set_flags(context, sp, f->version);
 444         if(f->version == KRB5_FCC_FVNO_4 && ret == 0) {
 445             /* V4 stuff */
 446             if (context->kdc_sec_offset) {
 447                 ret |= krb5_store_int16 (sp, 12); /* length */
 448                 ret |= krb5_store_int16 (sp, FCC_TAG_DELTATIME); /* Tag */
 449                 ret |= krb5_store_int16 (sp, 8); /* length of data */
 450                 ret |= krb5_store_int32 (sp, context->kdc_sec_offset);
 451                 ret |= krb5_store_int32 (sp, context->kdc_usec_offset);
 452             } else {
 453                 ret |= krb5_store_int16 (sp, 0);
 454             }
 455         }
 456         ret |= krb5_store_principal(sp, primary_principal);
 457
 458         ret |= write_storage(context, sp, fd);
 459
 460         krb5_storage_free(sp);
 461     }
 462     fcc_unlock(context, fd);
 463     if (close(fd) < 0)
 464         if (ret == 0) {
 465             char buf[128];
 466             ret = errno;
 467             rk_strerror_r(ret, buf, sizeof(buf));
 468             krb5_set_error_message (context, ret, N_("close %s: %s", ""),
 469                                     FILENAME(id), buf);
 470         }
 471     return ret;
 472 }
 473
 474 static krb5_error_code KRB5_CALLCONV
 475 fcc_close(krb5_context context,
 476           krb5_ccache id)
 477 {
 478     if (FCACHE(id) == NULL)
 479         return krb5_einval(context, 2);
 480
 481     free (FILENAME(id));
 482     krb5_data_free(&id->data);
 483     return 0;
 484 }
 485
 486 static krb5_error_code KRB5_CALLCONV
 487 fcc_destroy(krb5_context context,
 488             krb5_ccache id)
 489 {
 490     if (FCACHE(id) == NULL)
 491         return krb5_einval(context, 2);
 492
 493     _krb5_erase_file(context, FILENAME(id));
 494     return 0;
 495 }
 496
 497 static krb5_error_code KRB5_CALLCONV
 498 fcc_store_cred(krb5_context context,
 499                krb5_ccache id,
 500                krb5_creds *creds)
 501 {
 502     int ret;
 503     int fd;
 504
 505     ret = fcc_open(context, id, &fd, O_WRONLY | O_APPEND | O_BINARY | O_CLOEXEC, 0);
 506     if(ret)
 507         return ret;
 508     {
 509         krb5_storage *sp;
 510
 511         sp = krb5_storage_emem();
 512         krb5_storage_set_eof_code(sp, KRB5_CC_END);
 513         storage_set_flags(context, sp, FCACHE(id)->version);
 514         if (!krb5_config_get_bool_default(context, NULL, TRUE,
 515                                           "libdefaults",
 516                                           "fcc-mit-ticketflags",
 517                                           NULL))
 518             krb5_storage_set_flags(sp, KRB5_STORAGE_CREDS_FLAGS_WRONG_BITORDER);
 519         ret = krb5_store_creds(sp, creds);
 520         if (ret == 0)
 521             ret = write_storage(context, sp, fd);
 522         krb5_storage_free(sp);
 523     }
 524     fcc_unlock(context, fd);
 525     if (close(fd) < 0) {
 526         if (ret == 0) {
 527             char buf[128];
 528             rk_strerror_r(ret, buf, sizeof(buf));
 529             ret = errno;
 530             krb5_set_error_message (context, ret, N_("close %s: %s", ""),
 531                                     FILENAME(id), buf);
 532         }
 533     }
 534     return ret;
 535 }
 536
 537 static krb5_error_code
 538 init_fcc (krb5_context context,
 539           krb5_ccache id,
 540           krb5_storage **ret_sp,
 541           int *ret_fd,
 542           krb5_deltat *kdc_offset)
 543 {
 544     int fd;
 545     int8_t pvno, tag;
 546     krb5_storage *sp;
 547     krb5_error_code ret;
 548
 549     if (kdc_offset)
 550         *kdc_offset = 0;
 551
 552     ret = fcc_open(context, id, &fd, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
 553     if(ret)
 554         return ret;
 555
 556     sp = krb5_storage_from_fd(fd);
 557     if(sp == NULL) {
 558         krb5_clear_error_message(context);
 559         ret = ENOMEM;
 560         goto out;
 561     }
 562     krb5_storage_set_eof_code(sp, KRB5_CC_END);
 563     ret = krb5_ret_int8(sp, &pvno);
 564     if(ret != 0) {
 565         if(ret == KRB5_CC_END) {
 566             ret = ENOENT;
 567             krb5_set_error_message(context, ret,
 568                                    N_("Empty credential cache file: %s", ""),
 569                                    FILENAME(id));
 570         } else
 571             krb5_set_error_message(context, ret, N_("Error reading pvno "
 572                                                     "in cache file: %s", ""),
 573                                    FILENAME(id));
 574         goto out;
 575     }
 576     if(pvno != 5) {
 577         ret = KRB5_CCACHE_BADVNO;
 578         krb5_set_error_message(context, ret, N_("Bad version number in credential "
 579                                                 "cache file: %s", ""),
 580                                FILENAME(id));
 581         goto out;
 582     }
 583     ret = krb5_ret_int8(sp, &tag); /* should not be host byte order */
 584     if(ret != 0) {
 585         ret = KRB5_CC_FORMAT;
 586         krb5_set_error_message(context, ret, "Error reading tag in "
 587                               "cache file: %s", FILENAME(id));
 588         goto out;
 589     }
 590     FCACHE(id)->version = tag;
 591     storage_set_flags(context, sp, FCACHE(id)->version);
 592     switch (tag) {
 593     case KRB5_FCC_FVNO_4: {
 594         int16_t length;
 595
 596         ret = krb5_ret_int16 (sp, &length);
 597         if(ret) {
 598             ret = KRB5_CC_FORMAT;
 599             krb5_set_error_message(context, ret,
 600                                    N_("Error reading tag length in "
 601                                       "cache file: %s", ""), FILENAME(id));
 602             goto out;
 603         }
 604         while(length > 0) {
 605             int16_t dtag, data_len;
 606             int i;
 607             int8_t dummy;
 608
 609             ret = krb5_ret_int16 (sp, &dtag);
 610             if(ret) {
 611                 ret = KRB5_CC_FORMAT;
 612                 krb5_set_error_message(context, ret, N_("Error reading dtag in "
 613                                                         "cache file: %s", ""),
 614                                        FILENAME(id));
 615                 goto out;
 616             }
 617             ret = krb5_ret_int16 (sp, &data_len);
 618             if(ret) {
 619                 ret = KRB5_CC_FORMAT;
 620                 krb5_set_error_message(context, ret,
 621                                        N_("Error reading dlength "
 622                                           "in cache file: %s",""),
 623                                        FILENAME(id));
 624                 goto out;
 625             }
 626             switch (dtag) {
 627             case FCC_TAG_DELTATIME : {
 628                 int32_t offset;
 629
 630                 ret = krb5_ret_int32 (sp, &offset);
 631                 ret |= krb5_ret_int32 (sp, &context->kdc_usec_offset);
 632                 if(ret) {
 633                     ret = KRB5_CC_FORMAT;
 634                     krb5_set_error_message(context, ret,
 635                                            N_("Error reading kdc_sec in "
 636                                               "cache file: %s", ""),
 637                                            FILENAME(id));
 638                     goto out;
 639                 }
 640                 context->kdc_sec_offset = offset;
 641                 if (kdc_offset)
 642                     *kdc_offset = offset;
 643                 break;
 644             }
 645             default :
 646                 for (i = 0; i < data_len; ++i) {
 647                     ret = krb5_ret_int8 (sp, &dummy);
 648                     if(ret) {
 649                         ret = KRB5_CC_FORMAT;
 650                         krb5_set_error_message(context, ret,
 651                                                N_("Error reading unknown "
 652                                                   "tag in cache file: %s", ""),
 653                                                FILENAME(id));
 654                         goto out;
 655                     }
 656                 }
 657                 break;
 658             }
 659             length -= 4 + data_len;
 660         }
 661         break;
 662     }
 663     case KRB5_FCC_FVNO_3:
 664     case KRB5_FCC_FVNO_2:
 665     case KRB5_FCC_FVNO_1:
 666         break;
 667     default :
 668         ret = KRB5_CCACHE_BADVNO;
 669         krb5_set_error_message(context, ret,
 670                                N_("Unknown version number (%d) in "
 671                                   "credential cache file: %s", ""),
 672                                (int)tag, FILENAME(id));
 673         goto out;
 674     }
 675     *ret_sp = sp;
 676     *ret_fd = fd;
 677
 678     return 0;
 679   out:
 680     if(sp != NULL)
 681         krb5_storage_free(sp);
 682     fcc_unlock(context, fd);
 683     close(fd);
 684     return ret;
 685 }
 686
 687 static krb5_error_code KRB5_CALLCONV
 688 fcc_get_principal(krb5_context context,
 689                   krb5_ccache id,
 690                   krb5_principal *principal)
 691 {
 692     krb5_error_code ret;
 693     int fd;
 694     krb5_storage *sp;
 695
 696     ret = init_fcc (context, id, &sp, &fd, NULL);
 697     if (ret)
 698         return ret;
 699     ret = krb5_ret_principal(sp, principal);
 700     if (ret)
 701         krb5_clear_error_message(context);
 702     krb5_storage_free(sp);
 703     fcc_unlock(context, fd);
 704     close(fd);
 705     return ret;
 706 }
 707
 708 static krb5_error_code KRB5_CALLCONV
 709 fcc_end_get (krb5_context context,
 710              krb5_ccache id,
 711              krb5_cc_cursor *cursor);
 712
 713 static krb5_error_code KRB5_CALLCONV
 714 fcc_get_first (krb5_context context,
 715                krb5_ccache id,
 716                krb5_cc_cursor *cursor)
 717 {
 718     krb5_error_code ret;
 719     krb5_principal principal;
 720
 721     if (FCACHE(id) == NULL)
 722         return krb5_einval(context, 2);
 723
 724     *cursor = malloc(sizeof(struct fcc_cursor));
 725     if (*cursor == NULL) {
 726         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
 727         return ENOMEM;
 728     }
 729     memset(*cursor, 0, sizeof(struct fcc_cursor));
 730
 731     ret = init_fcc (context, id, &FCC_CURSOR(*cursor)->sp,
 732                     &FCC_CURSOR(*cursor)->fd, NULL);
 733     if (ret) {
 734         free(*cursor);
 735         *cursor = NULL;
 736         return ret;
 737     }
 738     ret = krb5_ret_principal (FCC_CURSOR(*cursor)->sp, &principal);
 739     if(ret) {
 740         krb5_clear_error_message(context);
 741         fcc_end_get(context, id, cursor);
 742         return ret;
 743     }
 744     krb5_free_principal (context, principal);
 745     fcc_unlock(context, FCC_CURSOR(*cursor)->fd);
 746     return 0;
 747 }
 748
 749 static krb5_error_code KRB5_CALLCONV
 750 fcc_get_next (krb5_context context,
 751               krb5_ccache id,
 752               krb5_cc_cursor *cursor,
 753               krb5_creds *creds)
 754 {
 755     krb5_error_code ret;
 756
 757     if (FCACHE(id) == NULL)
 758         return krb5_einval(context, 2);
 759
 760     if (FCC_CURSOR(*cursor) == NULL)
 761         return krb5_einval(context, 3);
 762
 763     if((ret = fcc_lock(context, id, FCC_CURSOR(*cursor)->fd, FALSE)) != 0)
 764         return ret;
 765
 766     ret = krb5_ret_creds(FCC_CURSOR(*cursor)->sp, creds);
 767     if (ret)
 768         krb5_clear_error_message(context);
 769
 770     fcc_unlock(context, FCC_CURSOR(*cursor)->fd);
 771     return ret;
 772 }
 773
 774 static krb5_error_code KRB5_CALLCONV
 775 fcc_end_get (krb5_context context,
 776              krb5_ccache id,
 777              krb5_cc_cursor *cursor)
 778 {
 779
 780     if (FCACHE(id) == NULL)
 781         return krb5_einval(context, 2);
 782
 783     if (FCC_CURSOR(*cursor) == NULL)
 784         return krb5_einval(context, 3);
 785
 786     krb5_storage_free(FCC_CURSOR(*cursor)->sp);
 787     close (FCC_CURSOR(*cursor)->fd);
 788     free(*cursor);
 789     *cursor = NULL;
 790     return 0;
 791 }
 792
 793 static krb5_error_code KRB5_CALLCONV
 794 fcc_remove_cred(krb5_context context,
 795                  krb5_ccache id,
 796                  krb5_flags which,
 797                  krb5_creds *cred)
 798 {
 799     krb5_error_code ret;
 800     krb5_ccache copy, newfile;
 801     char *newname = NULL;
 802     int fd;
 803
 804     if (FCACHE(id) == NULL)
 805         return krb5_einval(context, 2);
 806
 807     ret = krb5_cc_new_unique(context, krb5_cc_type_memory, NULL, &copy);
 808     if (ret)
 809         return ret;
 810
 811     ret = krb5_cc_copy_cache(context, id, copy);
 812     if (ret) {
 813         krb5_cc_destroy(context, copy);
 814         return ret;
 815     }
 816
 817     ret = krb5_cc_remove_cred(context, copy, which, cred);
 818     if (ret) {
 819         krb5_cc_destroy(context, copy);
 820         return ret;
 821     }
 822
 823     ret = asprintf(&newname, "FILE:%s.XXXXXX", FILENAME(id));
 824     if (ret < 0 || newname == NULL) {
 825         krb5_cc_destroy(context, copy);
 826         return ENOMEM;
 827     }
 828
 829     fd = mkstemp(&newname[5]);
 830     if (fd < 0) {
 831         ret = errno;
 832         krb5_cc_destroy(context, copy);
 833         return ret;
 834     }
 835     close(fd);
 836
 837     ret = krb5_cc_resolve(context, newname, &newfile);
 838     if (ret) {
 839         unlink(&newname[5]);
 840         free(newname);
 841         krb5_cc_destroy(context, copy);
 842         return ret;
 843     }
 844
 845     ret = krb5_cc_copy_cache(context, copy, newfile);
 846     krb5_cc_destroy(context, copy);
 847     if (ret) {
 848         free(newname);
 849         krb5_cc_destroy(context, newfile);
 850         return ret;
 851     }
 852
 853     ret = rk_rename(&newname[5], FILENAME(id));
 854     if (ret)
 855         ret = errno;
 856     free(newname);
 857     krb5_cc_close(context, newfile);
 858
 859     return ret;
 860 }
 861
 862 static krb5_error_code KRB5_CALLCONV
 863 fcc_set_flags(krb5_context context,
 864               krb5_ccache id,
 865               krb5_flags flags)
 866 {
 867     if (FCACHE(id) == NULL)
 868         return krb5_einval(context, 2);
 869
 870     return 0; /* XXX */
 871 }
 872
 873 static int KRB5_CALLCONV
 874 fcc_get_version(krb5_context context,
 875                 krb5_ccache id)
 876 {
 877     if (FCACHE(id) == NULL)
 878         return -1;
 879
 880     return FCACHE(id)->version;
 881 }
 882
 883 struct fcache_iter {
 884     int first;
 885 };
 886
 887 static krb5_error_code KRB5_CALLCONV
 888 fcc_get_cache_first(krb5_context context, krb5_cc_cursor *cursor)
 889 {
 890     struct fcache_iter *iter;
 891
 892     iter = calloc(1, sizeof(*iter));
 893     if (iter == NULL) {
 894         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
 895         return ENOMEM;
 896     }
 897     iter->first = 1;
 898     *cursor = iter;
 899     return 0;
 900 }
 901
 902 static krb5_error_code KRB5_CALLCONV
 903 fcc_get_cache_next(krb5_context context, krb5_cc_cursor cursor, krb5_ccache *id)
 904 {
 905     struct fcache_iter *iter = cursor;
 906     krb5_error_code ret;
 907     const char *fn;
 908     char *expandedfn = NULL;
 909
 910     if (iter == NULL)
 911         return krb5_einval(context, 2);
 912
 913     if (!iter->first) {
 914         krb5_clear_error_message(context);
 915         return KRB5_CC_END;
 916     }
 917     iter->first = 0;
 918
 919     fn = krb5_cc_default_name(context);
 920     if (fn == NULL || strncasecmp(fn, "FILE:", 5) != 0) {
 921         ret = _krb5_expand_default_cc_name(context,
 922                                            KRB5_DEFAULT_CCNAME_FILE,
 923                                            &expandedfn);
 924         if (ret)
 925             return ret;
 926         fn = expandedfn;
 927     }
 928     /* check if file exists, don't return a non existant "next" */
 929     if (strncasecmp(fn, "FILE:", 5) == 0) {
 930         struct stat sb;
 931         ret = stat(fn + 5, &sb);
 932         if (ret) {
 933             ret = KRB5_CC_END;
 934             goto out;
 935         }
 936     }
 937     ret = krb5_cc_resolve(context, fn, id);
 938  out:
 939     if (expandedfn)
 940         free(expandedfn);
 941
 942     return ret;
 943 }
 944
 945 static krb5_error_code KRB5_CALLCONV
 946 fcc_end_cache_get(krb5_context context, krb5_cc_cursor cursor)
 947 {
 948     struct fcache_iter *iter = cursor;
 949
 950     if (iter == NULL)
 951         return krb5_einval(context, 2);
 952
 953     free(iter);
 954     return 0;
 955 }
 956
 957 static krb5_error_code KRB5_CALLCONV
 958 fcc_move(krb5_context context, krb5_ccache from, krb5_ccache to)
 959 {
 960     krb5_error_code ret = 0;
 961
 962     ret = rk_rename(FILENAME(from), FILENAME(to));
 963
 964     if (ret && errno != EXDEV) {
 965         char buf[128];
 966         ret = errno;
 967         rk_strerror_r(ret, buf, sizeof(buf));
 968         krb5_set_error_message(context, ret,
 969                                N_("Rename of file from %s "
 970                                   "to %s failed: %s", ""),
 971                                FILENAME(from), FILENAME(to), buf);
 972         return ret;
 973     } else if (ret && errno == EXDEV) {
 974         /* make a copy and delete the orignal */
 975         krb5_ssize_t sz1, sz2;
 976         int fd1, fd2;
 977         char buf[BUFSIZ];
 978
 979         ret = fcc_open(context, from, &fd1, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
 980         if(ret)
 981             return ret;
 982
 983         unlink(FILENAME(to));
 984
 985         ret = fcc_open(context, to, &fd2,
 986                        O_WRONLY | O_CREAT | O_EXCL | O_BINARY | O_CLOEXEC, 0600);
 987         if(ret)
 988             goto out1;
 989
 990         while((sz1 = read(fd1, buf, sizeof(buf))) > 0) {
 991             sz2 = write(fd2, buf, sz1);
 992             if (sz1 != sz2) {
 993                 ret = EIO;
 994                 krb5_set_error_message(context, ret,
 995                                        N_("Failed to write data from one file "
 996                                           "credential cache to the other", ""));
 997                 goto out2;
 998             }
 999         }
1000         if (sz1 < 0) {
1001             ret = EIO;
1002             krb5_set_error_message(context, ret,
1003                                    N_("Failed to read data from one file "
1004                                       "credential cache to the other", ""));
1005             goto out2;
1006         }
1007     out2:
1008         fcc_unlock(context, fd2);
1009         close(fd2);
1010
1011     out1:
1012         fcc_unlock(context, fd1);
1013         close(fd1);
1014
1015         _krb5_erase_file(context, FILENAME(from));
1016
1017         if (ret) {
1018             _krb5_erase_file(context, FILENAME(to));
1019             return ret;
1020         }
1021     }
1022
1023     /* make sure ->version is uptodate */
1024     {
1025         krb5_storage *sp;
1026         int fd;
1027         if ((ret = init_fcc (context, to, &sp, &fd, NULL)) == 0) {
1028             if (sp)
1029                 krb5_storage_free(sp);
1030             fcc_unlock(context, fd);
1031             close(fd);
1032         }
1033     }
1034
1035     fcc_close(context, from);
1036
1037     return ret;
1038 }
1039
1040 static krb5_error_code KRB5_CALLCONV
1041 fcc_get_default_name(krb5_context context, char **str)
1042 {
1043     return _krb5_expand_default_cc_name(context,
1044                                         KRB5_DEFAULT_CCNAME_FILE,
1045                                         str);
1046 }
1047
1048 static krb5_error_code KRB5_CALLCONV
1049 fcc_lastchange(krb5_context context, krb5_ccache id, krb5_timestamp *mtime)
1050 {
1051     krb5_error_code ret;
1052     struct stat sb;
1053     int fd;
1054
1055     ret = fcc_open(context, id, &fd, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
1056     if(ret)
1057         return ret;
1058     ret = fstat(fd, &sb);
1059     close(fd);
1060     if (ret) {
1061         ret = errno;
1062         krb5_set_error_message(context, ret, N_("Failed to stat cache file", ""));
1063         return ret;
1064     }
1065     *mtime = sb.st_mtime;
1066     return 0;
1067 }
1068
1069 static krb5_error_code KRB5_CALLCONV
1070 fcc_set_kdc_offset(krb5_context context, krb5_ccache id, krb5_deltat kdc_offset)
1071 {
1072     return 0;
1073 }
1074
1075 static krb5_error_code KRB5_CALLCONV
1076 fcc_get_kdc_offset(krb5_context context, krb5_ccache id, krb5_deltat *kdc_offset)
1077 {
1078     krb5_error_code ret;
1079     krb5_storage *sp = NULL;
1080     int fd;
1081     ret = init_fcc(context, id, &sp, &fd, kdc_offset);
1082     if (sp)
1083         krb5_storage_free(sp);
1084     fcc_unlock(context, fd);
1085     close(fd);
1086
1087     return ret;
1088 }
1089
1090
1091 /**
1092  * Variable containing the FILE based credential cache implemention.
1093  *
1094  * @ingroup krb5_ccache
1095  */
1096
1097 KRB5_LIB_VARIABLE const krb5_cc_ops krb5_fcc_ops = {
1098     KRB5_CC_OPS_VERSION,
1099     "FILE",
1100     fcc_get_name,
1101     fcc_resolve,
1102     fcc_gen_new,
1103     fcc_initialize,
1104     fcc_destroy,
1105     fcc_close,
1106     fcc_store_cred,
1107     NULL, /* fcc_retrieve */
1108     fcc_get_principal,
1109     fcc_get_first,
1110     fcc_get_next,
1111     fcc_end_get,
1112     fcc_remove_cred,
1113     fcc_set_flags,
1114     fcc_get_version,
1115     fcc_get_cache_first,
1116     fcc_get_cache_next,
1117     fcc_end_cache_get,
1118     fcc_move,
1119     fcc_get_default_name,
1120     NULL,
1121     fcc_lastchange,
1122     fcc_set_kdc_offset,
1123     fcc_get_kdc_offset
1124 };