source4/heimdal/lib/krb5/mcache.c

   1 /*
   2  * Copyright (c) 1997-2004 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_mcache {
  39     char *name;
  40     unsigned int refcnt;
  41     unsigned int anonymous:1;
  42     unsigned int dead:1;
  43     krb5_principal primary_principal;
  44     struct link {
  45         krb5_creds cred;
  46         struct link *next;
  47     } *creds;
  48     struct krb5_mcache *next;
  49     time_t mtime;
  50     krb5_deltat kdc_offset;
  51     HEIMDAL_MUTEX mutex;
  52 } krb5_mcache;
  53
  54 static HEIMDAL_MUTEX mcc_mutex = HEIMDAL_MUTEX_INITIALIZER;
  55 static struct krb5_mcache *mcc_head;
  56
  57 #define MCACHE(X)       ((krb5_mcache *)(X)->data.data)
  58
  59 #define MISDEAD(X)      ((X)->dead)
  60
  61 static krb5_error_code KRB5_CALLCONV
  62 mcc_get_name_2(krb5_context context,
  63                krb5_ccache id,
  64                const char **name,
  65                const char **col,
  66                const char **sub)
  67 {
  68     if (name)
  69         *name = MCACHE(id)->name;
  70     if (col)
  71         *col = NULL;
  72     if (sub)
  73         *sub = MCACHE(id)->name;
  74     return 0;
  75 }
  76
  77 static krb5_error_code
  78 mcc_alloc(krb5_context context, const char *name, krb5_mcache **out)
  79 {
  80     krb5_mcache *m, *m_c;
  81     size_t counter = 0;
  82     int ret = 0;
  83     unsigned create_anonymous = 0;
  84
  85     *out = NULL;
  86     ALLOC(m, 1);
  87     if(m == NULL)
  88         return krb5_enomem(context);
  89
  90 again:
  91     if (counter > 3) {
  92         free(m->name);
  93         free(m);
  94         return EAGAIN; /* XXX */
  95     }
  96     if(name == NULL) {
  97         ret = asprintf(&m->name, "u%p-%llu", m, (unsigned long long)counter);
  98     } else if (strcmp(name, "anonymous") == 0) {
  99         ret = asprintf(&m->name, "anonymous-%p-%llu", m, (unsigned long long)counter);
 100         create_anonymous = 1;
 101     } else {
 102         m->name = strdup(name);
 103     }
 104     if(ret < 0 || m->name == NULL) {
 105         free(m);
 106         return krb5_enomem(context);
 107     }
 108
 109     /* check for dups first */
 110     HEIMDAL_MUTEX_lock(&mcc_mutex);
 111     for (m_c = mcc_head; m_c != NULL; m_c = m_c->next)
 112         if (strcmp(m->name, m_c->name) == 0)
 113             break;
 114     if (m_c) {
 115         free(m->name);
 116         free(m);
 117         if (name && !create_anonymous) {
 118             /* We raced with another thread to create this cache */
 119             m = m_c;
 120             HEIMDAL_MUTEX_lock(&(m->mutex));
 121             m->refcnt++;
 122             HEIMDAL_MUTEX_unlock(&(m->mutex));
 123         } else {
 124             /* How likely are we to conflict on new_unique anyways?? */
 125             counter++;
 126             free(m->name);
 127             m->name = NULL;
 128             HEIMDAL_MUTEX_unlock(&mcc_mutex);
 129             goto again;
 130         }
 131         HEIMDAL_MUTEX_unlock(&mcc_mutex);
 132         *out = m;
 133         return 0;
 134     }
 135
 136     m->anonymous = create_anonymous;
 137     m->dead = 0;
 138     m->refcnt = 1;
 139     m->primary_principal = NULL;
 140     m->creds = NULL;
 141     m->mtime = time(NULL);
 142     m->kdc_offset = 0;
 143     m->next = mcc_head;
 144     HEIMDAL_MUTEX_init(&(m->mutex));
 145     mcc_head = m;
 146     HEIMDAL_MUTEX_unlock(&mcc_mutex);
 147     *out = m;
 148     return 0;
 149 }
 150
 151 static krb5_error_code KRB5_CALLCONV
 152 mcc_resolve_2(krb5_context context,
 153               krb5_ccache *id,
 154               const char *res,
 155               const char *sub)
 156 {
 157     krb5_error_code ret;
 158     krb5_mcache *m;
 159
 160     if ((ret = mcc_alloc(context, sub && *sub ? sub : res, &m)))
 161         return ret;
 162
 163     (*id)->data.data = m;
 164     (*id)->data.length = sizeof(*m);
 165
 166     return 0;
 167 }
 168
 169
 170 static krb5_error_code KRB5_CALLCONV
 171 mcc_gen_new(krb5_context context, krb5_ccache *id)
 172 {
 173     krb5_error_code ret;
 174     krb5_mcache *m;
 175
 176     if ((ret = mcc_alloc(context, NULL, &m)))
 177         return ret;
 178
 179     (*id)->data.data = m;
 180     (*id)->data.length = sizeof(*m);
 181
 182     return 0;
 183 }
 184
 185 static void KRB5_CALLCONV
 186 mcc_destroy_internal(krb5_context context,
 187                      krb5_mcache *m)
 188 {
 189     struct link *l;
 190
 191     if (m->primary_principal != NULL) {
 192         krb5_free_principal (context, m->primary_principal);
 193         m->primary_principal = NULL;
 194     }
 195     m->dead = 1;
 196
 197     l = m->creds;
 198     while (l != NULL) {
 199         struct link *old;
 200
 201         krb5_free_cred_contents (context, &l->cred);
 202         old = l;
 203         l = l->next;
 204         free (old);
 205     }
 206
 207     m->creds = NULL;
 208     return;
 209 }
 210
 211 static krb5_error_code KRB5_CALLCONV
 212 mcc_initialize(krb5_context context,
 213                krb5_ccache id,
 214                krb5_principal primary_principal)
 215 {
 216     krb5_mcache *m = MCACHE(id);
 217     krb5_error_code ret = 0;
 218     HEIMDAL_MUTEX_lock(&(m->mutex));
 219     heim_assert(m->refcnt != 0, "resurection released mcache");
 220     /*
 221      * It's important to destroy any existing
 222      * creds here, that matches the baheviour
 223      * of all other backends and also the
 224      * MEMORY: backend in MIT.
 225      */
 226     mcc_destroy_internal(context, m);
 227     m->dead = 0;
 228     m->kdc_offset = 0;
 229     m->mtime = time(NULL);
 230     ret = krb5_copy_principal (context,
 231                                primary_principal,
 232                                &m->primary_principal);
 233     HEIMDAL_MUTEX_unlock(&(m->mutex));
 234     return ret;
 235 }
 236
 237 static int
 238 mcc_close_internal(krb5_mcache *m)
 239 {
 240     HEIMDAL_MUTEX_lock(&(m->mutex));
 241     heim_assert(m->refcnt != 0, "closed dead cache mcache");
 242     if (--m->refcnt != 0) {
 243         HEIMDAL_MUTEX_unlock(&(m->mutex));
 244         return 0;
 245     }
 246     if (MISDEAD(m)) {
 247         free(m->name);
 248         HEIMDAL_MUTEX_unlock(&(m->mutex));
 249         return 1;
 250     }
 251     HEIMDAL_MUTEX_unlock(&(m->mutex));
 252     return 0;
 253 }
 254
 255 static krb5_error_code KRB5_CALLCONV
 256 mcc_close(krb5_context context,
 257           krb5_ccache id)
 258 {
 259     krb5_mcache *m = MCACHE(id);
 260
 261     if (mcc_close_internal(MCACHE(id))) {
 262         HEIMDAL_MUTEX_destroy(&(m->mutex));
 263         krb5_data_free(&id->data);
 264     }
 265     return 0;
 266 }
 267
 268 static krb5_error_code KRB5_CALLCONV
 269 mcc_destroy(krb5_context context,
 270             krb5_ccache id)
 271 {
 272     krb5_mcache **n, *m = MCACHE(id);
 273
 274     HEIMDAL_MUTEX_lock(&mcc_mutex);
 275     HEIMDAL_MUTEX_lock(&(m->mutex));
 276     if (m->refcnt == 0)
 277     {
 278         HEIMDAL_MUTEX_unlock(&(m->mutex));
 279         HEIMDAL_MUTEX_unlock(&mcc_mutex);
 280         krb5_abortx(context, "mcc_destroy: refcnt already 0");
 281     }
 282
 283     if (!MISDEAD(m)) {
 284         /* if this is an active mcache, remove it from the linked
 285            list, and free all data */
 286         for(n = &mcc_head; n && *n; n = &(*n)->next) {
 287             if(m == *n) {
 288                 *n = m->next;
 289                 break;
 290             }
 291         }
 292         mcc_destroy_internal(context, m);
 293     }
 294     HEIMDAL_MUTEX_unlock(&(m->mutex));
 295     HEIMDAL_MUTEX_unlock(&mcc_mutex);
 296     return 0;
 297 }
 298
 299 static krb5_error_code KRB5_CALLCONV
 300 mcc_store_cred(krb5_context context,
 301                krb5_ccache id,
 302                krb5_creds *creds)
 303 {
 304     krb5_mcache *m = MCACHE(id);
 305     krb5_error_code ret;
 306     struct link *l;
 307
 308     HEIMDAL_MUTEX_lock(&(m->mutex));
 309     if (MISDEAD(m))
 310     {
 311         HEIMDAL_MUTEX_unlock(&(m->mutex));
 312         return ENOENT;
 313     }
 314
 315     l = malloc (sizeof(*l));
 316     if (l == NULL)
 317         return krb5_enomem(context);
 318     l->next = m->creds;
 319     m->creds = l;
 320     memset (&l->cred, 0, sizeof(l->cred));
 321     ret = krb5_copy_creds_contents (context, creds, &l->cred);
 322     if (ret) {
 323         m->creds = l->next;
 324         free (l);
 325         HEIMDAL_MUTEX_unlock(&(m->mutex));
 326         return ret;
 327     }
 328     m->mtime = time(NULL);
 329         HEIMDAL_MUTEX_unlock(&(m->mutex));
 330     return 0;
 331 }
 332
 333 static krb5_error_code KRB5_CALLCONV
 334 mcc_get_principal(krb5_context context,
 335                   krb5_ccache id,
 336                   krb5_principal *principal)
 337 {
 338     krb5_mcache *m = MCACHE(id);
 339     krb5_error_code ret = 0;
 340
 341     HEIMDAL_MUTEX_lock(&(m->mutex));
 342     if (MISDEAD(m) || m->primary_principal == NULL) {
 343         HEIMDAL_MUTEX_unlock(&(m->mutex));
 344         return ENOENT;
 345     }
 346     ret = krb5_copy_principal (context,
 347                                m->primary_principal,
 348                                principal);
 349     HEIMDAL_MUTEX_unlock(&(m->mutex));
 350     return ret;
 351 }
 352
 353 static krb5_error_code KRB5_CALLCONV
 354 mcc_get_first (krb5_context context,
 355                 krb5_ccache id,
 356                 krb5_cc_cursor *cursor)
 357 {
 358     krb5_mcache *m = MCACHE(id);
 359
 360     HEIMDAL_MUTEX_lock(&(m->mutex));
 361     if (MISDEAD(m)) {
 362         HEIMDAL_MUTEX_unlock(&(m->mutex));
 363         return ENOENT;
 364     }
 365     *cursor = m->creds;
 366
 367     HEIMDAL_MUTEX_unlock(&(m->mutex));
 368     return 0;
 369 }
 370
 371 static krb5_error_code KRB5_CALLCONV
 372 mcc_get_next (krb5_context context,
 373               krb5_ccache id,
 374               krb5_cc_cursor *cursor,
 375               krb5_creds *creds)
 376 {
 377     krb5_mcache *m = MCACHE(id);
 378     struct link *l;
 379
 380     HEIMDAL_MUTEX_lock(&(m->mutex));
 381     if (MISDEAD(m)) {
 382         HEIMDAL_MUTEX_unlock(&(m->mutex));
 383         return ENOENT;
 384     }
 385     HEIMDAL_MUTEX_unlock(&(m->mutex));
 386
 387     l = *cursor;
 388     if (l != NULL) {
 389         *cursor = l->next;
 390         return krb5_copy_creds_contents (context,
 391                                          &l->cred,
 392                                          creds);
 393     } else
 394         return KRB5_CC_END;
 395 }
 396
 397 static krb5_error_code KRB5_CALLCONV
 398 mcc_end_get (krb5_context context,
 399              krb5_ccache id,
 400              krb5_cc_cursor *cursor)
 401 {
 402     return 0;
 403 }
 404
 405 static krb5_error_code KRB5_CALLCONV
 406 mcc_remove_cred(krb5_context context,
 407                  krb5_ccache id,
 408                  krb5_flags which,
 409                  krb5_creds *mcreds)
 410 {
 411     krb5_mcache *m = MCACHE(id);
 412     struct link **q, *p;
 413
 414     HEIMDAL_MUTEX_lock(&(m->mutex));
 415
 416     for(q = &m->creds, p = *q; p; p = *q) {
 417         if(krb5_compare_creds(context, which, mcreds, &p->cred)) {
 418             *q = p->next;
 419             krb5_free_cred_contents(context, &p->cred);
 420             free(p);
 421             m->mtime = time(NULL);
 422         } else
 423             q = &p->next;
 424     }
 425     HEIMDAL_MUTEX_unlock(&(m->mutex));
 426     return 0;
 427 }
 428
 429 static krb5_error_code KRB5_CALLCONV
 430 mcc_set_flags(krb5_context context,
 431               krb5_ccache id,
 432               krb5_flags flags)
 433 {
 434     return 0; /* XXX */
 435 }
 436
 437 struct mcache_iter {
 438     krb5_mcache *cache;
 439 };
 440
 441 static krb5_mcache *
 442 mcc_get_cache_find_next_internal(krb5_mcache *next)
 443 {
 444     HEIMDAL_MUTEX_lock(&mcc_mutex);
 445     for (; next != NULL && next->anonymous; next = next->next) {
 446         /* noop: iterate over all anonymous entries */
 447     }
 448     if (next != NULL) {
 449         HEIMDAL_MUTEX_lock(&(next->mutex));
 450         next->refcnt++;
 451         HEIMDAL_MUTEX_unlock(&(next->mutex));
 452         next = next->next;
 453     }
 454     HEIMDAL_MUTEX_unlock(&mcc_mutex);
 455
 456     return next;
 457 }
 458
 459 static krb5_error_code KRB5_CALLCONV
 460 mcc_get_cache_first(krb5_context context, krb5_cc_cursor *cursor)
 461 {
 462     struct mcache_iter *iter;
 463
 464     iter = calloc(1, sizeof(*iter));
 465     if (iter == NULL)
 466         return krb5_enomem(context);
 467
 468     iter->cache = mcc_get_cache_find_next_internal(mcc_head);
 469
 470     *cursor = iter;
 471     return 0;
 472 }
 473
 474 static krb5_error_code KRB5_CALLCONV
 475 mcc_get_cache_next(krb5_context context, krb5_cc_cursor cursor, krb5_ccache *id)
 476 {
 477     struct mcache_iter *iter = cursor;
 478     krb5_error_code ret;
 479     krb5_mcache *m;
 480
 481     if (iter->cache == NULL)
 482         return KRB5_CC_END;
 483
 484     m = iter->cache;
 485     iter->cache = mcc_get_cache_find_next_internal(m);
 486
 487     ret = _krb5_cc_allocate(context, &krb5_mcc_ops, id);
 488     if (ret)
 489         return ret;
 490
 491     (*id)->data.data = m;
 492     (*id)->data.length = sizeof(*m);
 493
 494     return 0;
 495 }
 496
 497 static krb5_error_code KRB5_CALLCONV
 498 mcc_end_cache_get(krb5_context context, krb5_cc_cursor cursor)
 499 {
 500     struct mcache_iter *iter = cursor;
 501
 502     if (iter->cache)
 503         mcc_close_internal(iter->cache);
 504     iter->cache = NULL;
 505     free(iter);
 506     return 0;
 507 }
 508
 509 static krb5_error_code KRB5_CALLCONV
 510 mcc_move(krb5_context context, krb5_ccache from, krb5_ccache to)
 511 {
 512     krb5_mcache *mfrom = MCACHE(from), *mto = MCACHE(to);
 513     struct link *creds;
 514     krb5_principal principal;
 515     krb5_mcache **n;
 516
 517     HEIMDAL_MUTEX_lock(&mcc_mutex);
 518
 519     /* drop the from cache from the linked list to avoid lookups */
 520     for(n = &mcc_head; n && *n; n = &(*n)->next) {
 521         if(mfrom == *n) {
 522             *n = mfrom->next;
 523             break;
 524         }
 525     }
 526
 527     HEIMDAL_MUTEX_lock(&(mfrom->mutex));
 528     HEIMDAL_MUTEX_lock(&(mto->mutex));
 529     /* swap creds */
 530     creds = mto->creds;
 531     mto->creds = mfrom->creds;
 532     mfrom->creds = creds;
 533     /* swap principal */
 534     principal = mto->primary_principal;
 535     mto->primary_principal = mfrom->primary_principal;
 536     mfrom->primary_principal = principal;
 537
 538     mto->mtime = mfrom->mtime = time(NULL);
 539
 540     HEIMDAL_MUTEX_unlock(&(mfrom->mutex));
 541     HEIMDAL_MUTEX_unlock(&(mto->mutex));
 542     HEIMDAL_MUTEX_unlock(&mcc_mutex);
 543
 544     krb5_cc_destroy(context, from);
 545     return 0;
 546 }
 547
 548 static krb5_error_code KRB5_CALLCONV
 549 mcc_default_name(krb5_context context, char **str)
 550 {
 551     *str = strdup("MEMORY:");
 552     if (*str == NULL)
 553         return krb5_enomem(context);
 554     return 0;
 555 }
 556
 557 static krb5_error_code KRB5_CALLCONV
 558 mcc_lastchange(krb5_context context, krb5_ccache id, krb5_timestamp *mtime)
 559 {
 560     krb5_mcache *m = MCACHE(id);
 561     HEIMDAL_MUTEX_lock(&(m->mutex));
 562     *mtime = m->mtime;
 563     HEIMDAL_MUTEX_unlock(&(m->mutex));
 564     return 0;
 565 }
 566
 567 static krb5_error_code KRB5_CALLCONV
 568 mcc_set_kdc_offset(krb5_context context, krb5_ccache id, krb5_deltat kdc_offset)
 569 {
 570     krb5_mcache *m = MCACHE(id);
 571     HEIMDAL_MUTEX_lock(&(m->mutex));
 572     m->kdc_offset = kdc_offset;
 573     HEIMDAL_MUTEX_unlock(&(m->mutex));
 574     return 0;
 575 }
 576
 577 static krb5_error_code KRB5_CALLCONV
 578 mcc_get_kdc_offset(krb5_context context, krb5_ccache id, krb5_deltat *kdc_offset)
 579 {
 580     krb5_mcache *m = MCACHE(id);
 581     HEIMDAL_MUTEX_lock(&(m->mutex));
 582     *kdc_offset = m->kdc_offset;
 583     HEIMDAL_MUTEX_unlock(&(m->mutex));
 584     return 0;
 585 }
 586
 587
 588 /**
 589  * Variable containing the MEMORY based credential cache implemention.
 590  *
 591  * @ingroup krb5_ccache
 592  */
 593
 594 KRB5_LIB_VARIABLE const krb5_cc_ops krb5_mcc_ops = {
 595     KRB5_CC_OPS_VERSION_5,
 596     "MEMORY",
 597     NULL,
 598     NULL,
 599     mcc_gen_new,
 600     mcc_initialize,
 601     mcc_destroy,
 602     mcc_close,
 603     mcc_store_cred,
 604     NULL, /* mcc_retrieve */
 605     mcc_get_principal,
 606     mcc_get_first,
 607     mcc_get_next,
 608     mcc_end_get,
 609     mcc_remove_cred,
 610     mcc_set_flags,
 611     NULL,
 612     mcc_get_cache_first,
 613     mcc_get_cache_next,
 614     mcc_end_cache_get,
 615     mcc_move,
 616     mcc_default_name,
 617     NULL,
 618     mcc_lastchange,
 619     mcc_set_kdc_offset,
 620     mcc_get_kdc_offset,
 621     mcc_get_name_2,
 622     mcc_resolve_2
 623 };