lib/krb5/keytab_file.c

   1 /*
   2  * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 #define KRB5_KT_VNO_1 1
  37 #define KRB5_KT_VNO_2 2
  38 #define KRB5_KT_VNO   KRB5_KT_VNO_2
  39
  40 #define KRB5_KT_FL_JAVA 1
  41
  42
  43 /* file operations -------------------------------------------- */
  44
  45 struct fkt_data {
  46     char *filename;
  47     int flags;
  48 };
  49
  50 static krb5_error_code
  51 krb5_kt_ret_data(krb5_context context,
  52                  krb5_storage *sp,
  53                  krb5_data *data)
  54 {
  55     int ret;
  56     int16_t size;
  57     ret = krb5_ret_int16(sp, &size);
  58     if(ret)
  59         return ret;
  60     data->length = size;
  61     data->data = malloc(size);
  62     if (data->data == NULL) {
  63         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
  64         return ENOMEM;
  65     }
  66     ret = krb5_storage_read(sp, data->data, size);
  67     if(ret != size)
  68         return (ret < 0)? errno : KRB5_KT_END;
  69     return 0;
  70 }
  71
  72 static krb5_error_code
  73 krb5_kt_ret_string(krb5_context context,
  74                    krb5_storage *sp,
  75                    heim_general_string *data)
  76 {
  77     int ret;
  78     int16_t size;
  79     ret = krb5_ret_int16(sp, &size);
  80     if(ret)
  81         return ret;
  82     *data = malloc(size + 1);
  83     if (*data == NULL) {
  84         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
  85         return ENOMEM;
  86     }
  87     ret = krb5_storage_read(sp, *data, size);
  88     (*data)[size] = '\0';
  89     if(ret != size)
  90         return (ret < 0)? errno : KRB5_KT_END;
  91     return 0;
  92 }
  93
  94 static krb5_error_code
  95 krb5_kt_store_data(krb5_context context,
  96                    krb5_storage *sp,
  97                    krb5_data data)
  98 {
  99     int ret;
 100     ret = krb5_store_int16(sp, data.length);
 101     if(ret < 0)
 102         return ret;
 103     ret = krb5_storage_write(sp, data.data, data.length);
 104     if(ret != data.length){
 105         if(ret < 0)
 106             return errno;
 107         return KRB5_KT_END;
 108     }
 109     return 0;
 110 }
 111
 112 static krb5_error_code
 113 krb5_kt_store_string(krb5_storage *sp,
 114                      heim_general_string data)
 115 {
 116     int ret;
 117     size_t len = strlen(data);
 118     ret = krb5_store_int16(sp, len);
 119     if(ret < 0)
 120         return ret;
 121     ret = krb5_storage_write(sp, data, len);
 122     if(ret != len){
 123         if(ret < 0)
 124             return errno;
 125         return KRB5_KT_END;
 126     }
 127     return 0;
 128 }
 129
 130 static krb5_error_code
 131 krb5_kt_ret_keyblock(krb5_context context,
 132                      struct fkt_data *fkt,
 133                      krb5_storage *sp,
 134                      krb5_keyblock *p)
 135 {
 136     int ret;
 137     int16_t tmp;
 138
 139     ret = krb5_ret_int16(sp, &tmp); /* keytype + etype */
 140     if(ret)  {
 141         krb5_set_error_message(context, ret,
 142                                N_("Cant read keyblock from file %s", ""),
 143                                fkt->filename);
 144         return ret;
 145     }
 146     p->keytype = tmp;
 147     ret = krb5_kt_ret_data(context, sp, &p->keyvalue);
 148     if (ret)
 149         krb5_set_error_message(context, ret,
 150                                N_("Cant read keyblock from file %s", ""),
 151                                fkt->filename);
 152     return ret;
 153 }
 154
 155 static krb5_error_code
 156 krb5_kt_store_keyblock(krb5_context context,
 157                        struct fkt_data *fkt,
 158                        krb5_storage *sp,
 159                        krb5_keyblock *p)
 160 {
 161     int ret;
 162
 163     ret = krb5_store_int16(sp, p->keytype); /* keytype + etype */
 164     if(ret) {
 165         krb5_set_error_message(context, ret,
 166                                N_("Cant store keyblock to file %s", ""),
 167                                fkt->filename);
 168         return ret;
 169     }
 170     ret = krb5_kt_store_data(context, sp, p->keyvalue);
 171     if (ret)
 172         krb5_set_error_message(context, ret,
 173                                N_("Cant store keyblock to file %s", ""),
 174                                fkt->filename);
 175     return ret;
 176 }
 177
 178
 179 static krb5_error_code
 180 krb5_kt_ret_principal(krb5_context context,
 181                       struct fkt_data *fkt,
 182                       krb5_storage *sp,
 183                       krb5_principal *princ)
 184 {
 185     int i;
 186     int ret;
 187     krb5_principal p;
 188     int16_t len;
 189
 190     ALLOC(p, 1);
 191     if(p == NULL) {
 192         krb5_set_error_message(context, ENOMEM,
 193                                N_("malloc: out of memory", ""));
 194         return ENOMEM;
 195     }
 196
 197     ret = krb5_ret_int16(sp, &len);
 198     if(ret) {
 199         krb5_set_error_message(context, ret,
 200                                N_("Failed decoding length of "
 201                                   "keytab principal in keytab file %s", ""),
 202                                fkt->filename);
 203         goto out;
 204     }
 205     if(krb5_storage_is_flags(sp, KRB5_STORAGE_PRINCIPAL_WRONG_NUM_COMPONENTS))
 206         len--;
 207     if (len < 0) {
 208         ret = KRB5_KT_END;
 209         krb5_set_error_message(context, ret,
 210                                N_("Keytab principal contains "
 211                                   "invalid length in keytab %s", ""),
 212                                fkt->filename);
 213         goto out;
 214     }
 215     ret = krb5_kt_ret_string(context, sp, &p->realm);
 216     if(ret) {
 217         krb5_set_error_message(context, ret,
 218                                N_("Can't read realm from keytab: %s", ""),
 219                                fkt->filename);
 220         goto out;
 221     }
 222     p->name.name_string.val = calloc(len, sizeof(*p->name.name_string.val));
 223     if(p->name.name_string.val == NULL) {
 224         ret = ENOMEM;
 225         krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
 226         goto out;
 227     }
 228     p->name.name_string.len = len;
 229     for(i = 0; i < p->name.name_string.len; i++){
 230         ret = krb5_kt_ret_string(context, sp, p->name.name_string.val + i);
 231         if(ret) {
 232             krb5_set_error_message(context, ret,
 233                                    N_("Can't read principal from "
 234                                       "keytab: %s", ""),
 235                                    fkt->filename);
 236             goto out;
 237         }
 238     }
 239     if (krb5_storage_is_flags(sp, KRB5_STORAGE_PRINCIPAL_NO_NAME_TYPE))
 240         p->name.name_type = KRB5_NT_UNKNOWN;
 241     else {
 242         int32_t tmp32;
 243         ret = krb5_ret_int32(sp, &tmp32);
 244         p->name.name_type = tmp32;
 245         if (ret) {
 246             krb5_set_error_message(context, ret,
 247                                    N_("Can't read name-type from "
 248                                       "keytab: %s", ""),
 249                                    fkt->filename);
 250             goto out;
 251         }
 252     }
 253     *princ = p;
 254     return 0;
 255 out:
 256     krb5_free_principal(context, p);
 257     return ret;
 258 }
 259
 260 static krb5_error_code
 261 krb5_kt_store_principal(krb5_context context,
 262                         krb5_storage *sp,
 263                         krb5_principal p)
 264 {
 265     int i;
 266     int ret;
 267
 268     if(krb5_storage_is_flags(sp, KRB5_STORAGE_PRINCIPAL_WRONG_NUM_COMPONENTS))
 269         ret = krb5_store_int16(sp, p->name.name_string.len + 1);
 270     else
 271         ret = krb5_store_int16(sp, p->name.name_string.len);
 272     if(ret) return ret;
 273     ret = krb5_kt_store_string(sp, p->realm);
 274     if(ret) return ret;
 275     for(i = 0; i < p->name.name_string.len; i++){
 276         ret = krb5_kt_store_string(sp, p->name.name_string.val[i]);
 277         if(ret)
 278             return ret;
 279     }
 280     if(!krb5_storage_is_flags(sp, KRB5_STORAGE_PRINCIPAL_NO_NAME_TYPE)) {
 281         ret = krb5_store_int32(sp, p->name.name_type);
 282         if(ret)
 283             return ret;
 284     }
 285
 286     return 0;
 287 }
 288
 289 static krb5_error_code
 290 fkt_resolve(krb5_context context, const char *name, krb5_keytab id)
 291 {
 292     struct fkt_data *d;
 293
 294     d = malloc(sizeof(*d));
 295     if(d == NULL) {
 296         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
 297         return ENOMEM;
 298     }
 299     d->filename = strdup(name);
 300     if(d->filename == NULL) {
 301         free(d);
 302         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
 303         return ENOMEM;
 304     }
 305     d->flags = 0;
 306     id->data = d;
 307     return 0;
 308 }
 309
 310 static krb5_error_code
 311 fkt_resolve_java14(krb5_context context, const char *name, krb5_keytab id)
 312 {
 313     krb5_error_code ret;
 314
 315     ret = fkt_resolve(context, name, id);
 316     if (ret == 0) {
 317         struct fkt_data *d = id->data;
 318         d->flags |= KRB5_KT_FL_JAVA;
 319     }
 320     return ret;
 321 }
 322
 323 static krb5_error_code
 324 fkt_close(krb5_context context, krb5_keytab id)
 325 {
 326     struct fkt_data *d = id->data;
 327     free(d->filename);
 328     free(d);
 329     return 0;
 330 }
 331
 332 static krb5_error_code
 333 fkt_destroy(krb5_context context, krb5_keytab id)
 334 {
 335     struct fkt_data *d = id->data;
 336     _krb5_erase_file(context, d->filename);
 337     return 0;
 338 }
 339
 340 static krb5_error_code
 341 fkt_get_name(krb5_context context,
 342              krb5_keytab id,
 343              char *name,
 344              size_t namesize)
 345 {
 346     /* This function is XXX */
 347     struct fkt_data *d = id->data;
 348     strlcpy(name, d->filename, namesize);
 349     return 0;
 350 }
 351
 352 static void
 353 storage_set_flags(krb5_context context, krb5_storage *sp, int vno)
 354 {
 355     int flags = 0;
 356     switch(vno) {
 357     case KRB5_KT_VNO_1:
 358         flags |= KRB5_STORAGE_PRINCIPAL_WRONG_NUM_COMPONENTS;
 359         flags |= KRB5_STORAGE_PRINCIPAL_NO_NAME_TYPE;
 360         flags |= KRB5_STORAGE_HOST_BYTEORDER;
 361         break;
 362     case KRB5_KT_VNO_2:
 363         break;
 364     default:
 365         krb5_warnx(context,
 366                    "storage_set_flags called with bad vno (%d)", vno);
 367     }
 368     krb5_storage_set_flags(sp, flags);
 369 }
 370
 371 static krb5_error_code
 372 fkt_start_seq_get_int(krb5_context context,
 373                       krb5_keytab id,
 374                       int flags,
 375                       int exclusive,
 376                       krb5_kt_cursor *c)
 377 {
 378     int8_t pvno, tag;
 379     krb5_error_code ret;
 380     struct fkt_data *d = id->data;
 381
 382     c->fd = open (d->filename, flags);
 383     if (c->fd < 0) {
 384         ret = errno;
 385         krb5_set_error_message(context, ret,
 386                                N_("keytab %s open failed: %s", ""),
 387                                d->filename, strerror(ret));
 388         return ret;
 389     }
 390     rk_cloexec(c->fd);
 391     ret = _krb5_xlock(context, c->fd, exclusive, d->filename);
 392     if (ret) {
 393         close(c->fd);
 394         return ret;
 395     }
 396     c->sp = krb5_storage_from_fd(c->fd);
 397     if (c->sp == NULL) {
 398         _krb5_xunlock(context, c->fd);
 399         close(c->fd);
 400         krb5_set_error_message(context, ENOMEM,
 401                                N_("malloc: out of memory", ""));
 402         return ENOMEM;
 403     }
 404     krb5_storage_set_eof_code(c->sp, KRB5_KT_END);
 405     ret = krb5_ret_int8(c->sp, &pvno);
 406     if(ret) {
 407         krb5_storage_free(c->sp);
 408         _krb5_xunlock(context, c->fd);
 409         close(c->fd);
 410         krb5_clear_error_message(context);
 411         return ret;
 412     }
 413     if(pvno != 5) {
 414         krb5_storage_free(c->sp);
 415         _krb5_xunlock(context, c->fd);
 416         close(c->fd);
 417         krb5_clear_error_message (context);
 418         return KRB5_KEYTAB_BADVNO;
 419     }
 420     ret = krb5_ret_int8(c->sp, &tag);
 421     if (ret) {
 422         krb5_storage_free(c->sp);
 423         _krb5_xunlock(context, c->fd);
 424         close(c->fd);
 425         krb5_clear_error_message(context);
 426         return ret;
 427     }
 428     id->version = tag;
 429     storage_set_flags(context, c->sp, id->version);
 430     return 0;
 431 }
 432
 433 static krb5_error_code
 434 fkt_start_seq_get(krb5_context context,
 435                   krb5_keytab id,
 436                   krb5_kt_cursor *c)
 437 {
 438     return fkt_start_seq_get_int(context, id, O_RDONLY | O_BINARY | O_CLOEXEC, 0, c);
 439 }
 440
 441 static krb5_error_code
 442 fkt_next_entry_int(krb5_context context,
 443                    krb5_keytab id,
 444                    krb5_keytab_entry *entry,
 445                    krb5_kt_cursor *cursor,
 446                    off_t *start,
 447                    off_t *end)
 448 {
 449     struct fkt_data *d = id->data;
 450     int32_t len;
 451     int ret;
 452     int8_t tmp8;
 453     int32_t tmp32;
 454     uint32_t utmp32;
 455     off_t pos, curpos;
 456
 457     pos = krb5_storage_seek(cursor->sp, 0, SEEK_CUR);
 458 loop:
 459     ret = krb5_ret_int32(cursor->sp, &len);
 460     if (ret)
 461         return ret;
 462     if(len < 0) {
 463         pos = krb5_storage_seek(cursor->sp, -len, SEEK_CUR);
 464         goto loop;
 465     }
 466     ret = krb5_kt_ret_principal (context, d, cursor->sp, &entry->principal);
 467     if (ret)
 468         goto out;
 469     ret = krb5_ret_uint32(cursor->sp, &utmp32);
 470     entry->timestamp = utmp32;
 471     if (ret)
 472         goto out;
 473     ret = krb5_ret_int8(cursor->sp, &tmp8);
 474     if (ret)
 475         goto out;
 476     entry->vno = tmp8;
 477     ret = krb5_kt_ret_keyblock (context, d, cursor->sp, &entry->keyblock);
 478     if (ret)
 479         goto out;
 480     /* there might be a 32 bit kvno here
 481      * if it's zero, assume that the 8bit one was right,
 482      * otherwise trust the new value */
 483     curpos = krb5_storage_seek(cursor->sp, 0, SEEK_CUR);
 484     if(len + 4 + pos - curpos >= 4) {
 485         ret = krb5_ret_int32(cursor->sp, &tmp32);
 486         if (ret == 0 && tmp32 != 0)
 487             entry->vno = tmp32;
 488     }
 489     /* there might be a flags field here */
 490     if(len + 4 + pos - curpos >= 8) {
 491         ret = krb5_ret_uint32(cursor->sp, &utmp32);
 492         if (ret == 0)
 493             entry->flags = utmp32;
 494     } else
 495         entry->flags = 0;
 496
 497     entry->aliases = NULL;
 498
 499     if(start) *start = pos;
 500     if(end) *end = pos + 4 + len;
 501  out:
 502     krb5_storage_seek(cursor->sp, pos + 4 + len, SEEK_SET);
 503     return ret;
 504 }
 505
 506 static krb5_error_code
 507 fkt_next_entry(krb5_context context,
 508                krb5_keytab id,
 509                krb5_keytab_entry *entry,
 510                krb5_kt_cursor *cursor)
 511 {
 512     return fkt_next_entry_int(context, id, entry, cursor, NULL, NULL);
 513 }
 514
 515 static krb5_error_code
 516 fkt_end_seq_get(krb5_context context,
 517                 krb5_keytab id,
 518                 krb5_kt_cursor *cursor)
 519 {
 520     krb5_storage_free(cursor->sp);
 521     _krb5_xunlock(context, cursor->fd);
 522     close(cursor->fd);
 523     return 0;
 524 }
 525
 526 static krb5_error_code
 527 fkt_setup_keytab(krb5_context context,
 528                  krb5_keytab id,
 529                  krb5_storage *sp)
 530 {
 531     krb5_error_code ret;
 532     ret = krb5_store_int8(sp, 5);
 533     if(ret)
 534         return ret;
 535     if(id->version == 0)
 536         id->version = KRB5_KT_VNO;
 537     return krb5_store_int8 (sp, id->version);
 538 }
 539
 540 static krb5_error_code
 541 fkt_add_entry(krb5_context context,
 542               krb5_keytab id,
 543               krb5_keytab_entry *entry)
 544 {
 545     int ret;
 546     int fd;
 547     krb5_storage *sp;
 548     struct fkt_data *d = id->data;
 549     krb5_data keytab;
 550     int32_t len;
 551
 552     fd = open (d->filename, O_RDWR | O_BINARY | O_CLOEXEC);
 553     if (fd < 0) {
 554         fd = open (d->filename, O_RDWR | O_CREAT | O_EXCL | O_BINARY | O_CLOEXEC, 0600);
 555         if (fd < 0) {
 556             ret = errno;
 557             krb5_set_error_message(context, ret,
 558                                    N_("open(%s): %s", ""), d->filename,
 559                                    strerror(ret));
 560             return ret;
 561         }
 562         rk_cloexec(fd);
 563
 564         ret = _krb5_xlock(context, fd, 1, d->filename);
 565         if (ret) {
 566             close(fd);
 567             return ret;
 568         }
 569         sp = krb5_storage_from_fd(fd);
 570         krb5_storage_set_eof_code(sp, KRB5_KT_END);
 571         ret = fkt_setup_keytab(context, id, sp);
 572         if(ret) {
 573             goto out;
 574         }
 575         storage_set_flags(context, sp, id->version);
 576     } else {
 577         int8_t pvno, tag;
 578
 579         rk_cloexec(fd);
 580
 581         ret = _krb5_xlock(context, fd, 1, d->filename);
 582         if (ret) {
 583             close(fd);
 584             return ret;
 585         }
 586         sp = krb5_storage_from_fd(fd);
 587         krb5_storage_set_eof_code(sp, KRB5_KT_END);
 588         ret = krb5_ret_int8(sp, &pvno);
 589         if(ret) {
 590             /* we probably have a zero byte file, so try to set it up
 591                properly */
 592             ret = fkt_setup_keytab(context, id, sp);
 593             if(ret) {
 594                 krb5_set_error_message(context, ret,
 595                                        N_("%s: keytab is corrupted: %s", ""),
 596                                        d->filename, strerror(ret));
 597                 goto out;
 598             }
 599             storage_set_flags(context, sp, id->version);
 600         } else {
 601             if(pvno != 5) {
 602                 ret = KRB5_KEYTAB_BADVNO;
 603                 krb5_set_error_message(context, ret,
 604                                        N_("Bad version in keytab %s", ""),
 605                                        d->filename);
 606                 goto out;
 607             }
 608             ret = krb5_ret_int8 (sp, &tag);
 609             if (ret) {
 610                 krb5_set_error_message(context, ret,
 611                                        N_("failed reading tag from "
 612                                           "keytab %s", ""),
 613                                        d->filename);
 614                 goto out;
 615             }
 616             id->version = tag;
 617             storage_set_flags(context, sp, id->version);
 618         }
 619     }
 620
 621     {
 622         krb5_storage *emem;
 623         emem = krb5_storage_emem();
 624         if(emem == NULL) {
 625             ret = ENOMEM;
 626             krb5_set_error_message(context, ret,
 627                                    N_("malloc: out of memory", ""));
 628             goto out;
 629         }
 630         ret = krb5_kt_store_principal(context, emem, entry->principal);
 631         if(ret) {
 632             krb5_set_error_message(context, ret,
 633                                    N_("Failed storing principal "
 634                                       "in keytab %s", ""),
 635                                    d->filename);
 636             krb5_storage_free(emem);
 637             goto out;
 638         }
 639         ret = krb5_store_int32 (emem, entry->timestamp);
 640         if(ret) {
 641             krb5_set_error_message(context, ret,
 642                                    N_("Failed storing timpstamp "
 643                                       "in keytab %s", ""),
 644                                    d->filename);
 645             krb5_storage_free(emem);
 646             goto out;
 647         }
 648         ret = krb5_store_int8 (emem, entry->vno % 256);
 649         if(ret) {
 650             krb5_set_error_message(context, ret,
 651                                    N_("Failed storing kvno "
 652                                       "in keytab %s", ""),
 653                                    d->filename);
 654             krb5_storage_free(emem);
 655             goto out;
 656         }
 657         ret = krb5_kt_store_keyblock (context, d, emem, &entry->keyblock);
 658         if(ret) {
 659             krb5_storage_free(emem);
 660             goto out;
 661         }
 662         if ((d->flags & KRB5_KT_FL_JAVA) == 0) {
 663             ret = krb5_store_int32 (emem, entry->vno);
 664             if (ret) {
 665                 krb5_set_error_message(context, ret,
 666                                        N_("Failed storing extended kvno "
 667                                           "in keytab %s", ""),
 668                                        d->filename);
 669                 krb5_storage_free(emem);
 670                 goto out;
 671             }
 672             ret = krb5_store_uint32 (emem, entry->flags);
 673             if (ret) {
 674                 krb5_set_error_message(context, ret,
 675                                        N_("Failed storing extended kvno "
 676                                           "in keytab %s", ""),
 677                                        d->filename);
 678                 krb5_storage_free(emem);
 679                 goto out;
 680             }
 681         }
 682
 683         ret = krb5_storage_to_data(emem, &keytab);
 684         krb5_storage_free(emem);
 685         if(ret) {
 686             krb5_set_error_message(context, ret,
 687                                    N_("Failed converting keytab entry "
 688                                       "to memory block for keytab %s", ""),
 689                                    d->filename);
 690             goto out;
 691         }
 692     }
 693
 694     while(1) {
 695         ret = krb5_ret_int32(sp, &len);
 696         if(ret == KRB5_KT_END) {
 697             len = keytab.length;
 698             break;
 699         }
 700         if(len < 0) {
 701             len = -len;
 702             if(len >= keytab.length) {
 703                 krb5_storage_seek(sp, -4, SEEK_CUR);
 704                 break;
 705             }
 706         }
 707         krb5_storage_seek(sp, len, SEEK_CUR);
 708     }
 709     ret = krb5_store_int32(sp, len);
 710     if(krb5_storage_write(sp, keytab.data, keytab.length) < 0) {
 711         ret = errno;
 712         krb5_set_error_message(context, ret,
 713                                N_("Failed writing keytab block "
 714                                   "in keytab %s: %s", ""),
 715                                d->filename, strerror(ret));
 716     }
 717     memset(keytab.data, 0, keytab.length);
 718     krb5_data_free(&keytab);
 719   out:
 720     krb5_storage_free(sp);
 721     _krb5_xunlock(context, fd);
 722     close(fd);
 723     return ret;
 724 }
 725
 726 static krb5_error_code
 727 fkt_remove_entry(krb5_context context,
 728                  krb5_keytab id,
 729                  krb5_keytab_entry *entry)
 730 {
 731     krb5_keytab_entry e;
 732     krb5_kt_cursor cursor;
 733     off_t pos_start, pos_end;
 734     int found = 0;
 735     krb5_error_code ret;
 736
 737     ret = fkt_start_seq_get_int(context, id, O_RDWR | O_BINARY | O_CLOEXEC, 1, &cursor);
 738     if(ret != 0)
 739         goto out; /* return other error here? */
 740     while(fkt_next_entry_int(context, id, &e, &cursor,
 741                              &pos_start, &pos_end) == 0) {
 742         if(krb5_kt_compare(context, &e, entry->principal,
 743                            entry->vno, entry->keyblock.keytype)) {
 744             int32_t len;
 745             unsigned char buf[128];
 746             found = 1;
 747             krb5_storage_seek(cursor.sp, pos_start, SEEK_SET);
 748             len = pos_end - pos_start - 4;
 749             krb5_store_int32(cursor.sp, -len);
 750             memset(buf, 0, sizeof(buf));
 751             while(len > 0) {
 752                 krb5_storage_write(cursor.sp, buf, min(len, sizeof(buf)));
 753                 len -= min(len, sizeof(buf));
 754             }
 755         }
 756         krb5_kt_free_entry(context, &e);
 757     }
 758     krb5_kt_end_seq_get(context, id, &cursor);
 759   out:
 760     if (!found) {
 761         krb5_clear_error_message (context);
 762         return KRB5_KT_NOTFOUND;
 763     }
 764     return 0;
 765 }
 766
 767 const krb5_kt_ops krb5_fkt_ops = {
 768     "FILE",
 769     fkt_resolve,
 770     fkt_get_name,
 771     fkt_close,
 772     fkt_destroy,
 773     NULL, /* get */
 774     fkt_start_seq_get,
 775     fkt_next_entry,
 776     fkt_end_seq_get,
 777     fkt_add_entry,
 778     fkt_remove_entry
 779 };
 780
 781 const krb5_kt_ops krb5_wrfkt_ops = {
 782     "WRFILE",
 783     fkt_resolve,
 784     fkt_get_name,
 785     fkt_close,
 786     fkt_destroy,
 787     NULL, /* get */
 788     fkt_start_seq_get,
 789     fkt_next_entry,
 790     fkt_end_seq_get,
 791     fkt_add_entry,
 792     fkt_remove_entry
 793 };
 794
 795 const krb5_kt_ops krb5_javakt_ops = {
 796     "JAVA14",
 797     fkt_resolve_java14,
 798     fkt_get_name,
 799     fkt_close,
 800     fkt_destroy,
 801     NULL, /* get */
 802     fkt_start_seq_get,
 803     fkt_next_entry,
 804     fkt_end_seq_get,
 805     fkt_add_entry,
 806     fkt_remove_entry
 807 };