third_party/heimdal/lib/gssapi/mech/gss_mech_switch.c

   1 /*-
   2  * Copyright (c) 2005 Doug Rabson
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  *      $FreeBSD: src/lib/libgssapi/gss_mech_switch.c,v 1.2 2006/02/04 09:40:21 dfr Exp $
  27  */
  28
  29 #include "mech_locl.h"
  30 #include <heim_threads.h>
  31
  32 #ifndef _PATH_GSS_MECH
  33 #define _PATH_GSS_MECH  "/etc/gss/mech"
  34 #endif
  35
  36 struct _gss_mech_switch_list _gss_mechs = { NULL, NULL } ;
  37 gss_OID_set _gss_mech_oids;
  38 static HEIMDAL_MUTEX _gss_mech_mutex = HEIMDAL_MUTEX_INITIALIZER;
  39
  40 /*
  41  * Convert a string containing an OID in 'dot' form
  42  * (e.g. 1.2.840.113554.1.2.2) to a gss_OID.
  43  */
  44 static int
  45 _gss_string_to_oid(const char* s, gss_OID *oidp)
  46 {
  47         int                     number_count, i, j;
  48         size_t                  byte_count;
  49         const char              *p, *q;
  50         char                    *res;
  51         gss_OID_desc            oid;
  52
  53         *oidp = GSS_C_NO_OID;
  54
  55         /*
  56          * First figure out how many numbers in the oid, then
  57          * calculate the compiled oid size.
  58          */
  59         number_count = 0;
  60         for (p = s; p; p = q) {
  61                 q = strchr(p, '.');
  62                 if (q) q = q + 1;
  63                 number_count++;
  64         }
  65
  66         /*
  67          * The first two numbers are in the first byte and each
  68          * subsequent number is encoded in a variable byte sequence.
  69          */
  70         if (number_count < 2)
  71                 return (EINVAL);
  72
  73         /*
  74          * We do this in two passes. The first pass, we just figure
  75          * out the size. Second time around, we actually encode the
  76          * number.
  77          */
  78         res = 0;
  79         for (i = 0; i < 2; i++) {
  80                 byte_count = 0;
  81                 for (p = s, j = 0; p; p = q, j++) {
  82                         unsigned int number = 0;
  83
  84                         /*
  85                          * Find the end of this number.
  86                          */
  87                         q = strchr(p, '.');
  88                         if (q) q = q + 1;
  89
  90                         /*
  91                          * Read the number of of the string. Don't
  92                          * bother with anything except base ten.
  93                          */
  94                         while (*p && *p != '.') {
  95                                 number = 10 * number + (*p - '0');
  96                                 p++;
  97                         }
  98
  99                         /*
 100                          * Encode the number. The first two numbers
 101                          * are packed into the first byte. Subsequent
 102                          * numbers are encoded in bytes seven bits at
 103                          * a time with the last byte having the high
 104                          * bit set.
 105                          */
 106                         if (j == 0) {
 107                                 if (res)
 108                                         *res = number * 40;
 109                         } else if (j == 1) {
 110                                 if (res) {
 111                                         *res += number;
 112                                         res++;
 113                                 }
 114                                 byte_count++;
 115                         } else if (j >= 2) {
 116                                 /*
 117                                  * The number is encoded in seven bit chunks.
 118                                  */
 119                                 unsigned int t;
 120                                 unsigned int bytes;
 121
 122                                 bytes = 0;
 123                                 for (t = number; t; t >>= 7)
 124                                         bytes++;
 125                                 if (bytes == 0) bytes = 1;
 126                                 while (bytes) {
 127                                         if (res) {
 128                                                 int bit = 7*(bytes-1);
 129
 130                                                 *res = (number >> bit) & 0x7f;
 131                                                 if (bytes != 1)
 132                                                         *res |= 0x80;
 133                                                 res++;
 134                                         }
 135                                         byte_count++;
 136                                         bytes--;
 137                                 }
 138                         }
 139                 }
 140                 if (!res) {
 141                         res = malloc(byte_count);
 142                         if (!res)
 143                                 return (ENOMEM);
 144                         oid.length = byte_count;
 145                         oid.elements = res;
 146                 }
 147         }
 148
 149         {
 150                 OM_uint32 minor_status, tmp;
 151
 152                 if (GSS_ERROR(_gss_intern_oid(&minor_status, &oid, oidp))) {
 153                         _gss_free_oid(&tmp, &oid);
 154                         return (minor_status);
 155                 }
 156
 157                 _gss_free_oid(&tmp, &oid);
 158         }
 159
 160         return (0);
 161 }
 162
 163 #define SYM(name)                                                       \
 164 do {                                                                    \
 165         m->gm_mech.gm_ ## name = (_gss_##name##_t *)dlsym(so, "gss_" #name); \
 166         if (!m->gm_mech.gm_ ## name ||                                  \
 167             m->gm_mech.gm_ ##name == gss_ ## name) {                    \
 168                 _gss_mg_log(1, "can't find symbol gss_" #name "\n");    \
 169                 goto bad;                                               \
 170         }                                                               \
 171 } while (0)
 172
 173 #define OPTSYM(name)                                                    \
 174 do {                                                                    \
 175         m->gm_mech.gm_ ## name =  (_gss_##name##_t *)dlsym(so, "gss_" #name); \
 176         if (m->gm_mech.gm_ ## name == gss_ ## name)                     \
 177                 m->gm_mech.gm_ ## name = NULL;                          \
 178 } while (0)
 179
 180 /* mech exports gssspi_XXX, internally referred to as gss_XXX */
 181 #define OPTSPISYM(name)                                                 \
 182 do {                                                                    \
 183         m->gm_mech.gm_ ## name =  (_gss_##name##_t *)dlsym(so, "gssspi_" #name); \
 184 } while (0)
 185
 186 /* mech exports gssspi_XXX, internally referred to as gssspi_XXX */
 187 #define OPTSPISPISYM(name)                                                      \
 188 do {                                                                    \
 189         m->gm_mech.gm_ ## name =  (_gss_##name##_t *)dlsym(so, "gssspi_" #name); \
 190         if (m->gm_mech.gm_ ## name == gssspi_ ## name)                  \
 191                 m->gm_mech.gm_ ## name = NULL;                          \
 192 } while (0)
 193
 194 #define COMPATSYM(name)                                                 \
 195 do {                                                                    \
 196         m->gm_mech.gm_compat->gmc_ ## name =  (_gss_##name##_t *)dlsym(so, "gss_" #name); \
 197         if (m->gm_mech.gm_compat->gmc_ ## name == gss_ ## name)         \
 198                 m->gm_mech.gm_compat->gmc_ ## name = NULL;              \
 199 } while (0)
 200
 201 #define COMPATSPISYM(name)                                              \
 202 do {                                                                    \
 203         m->gm_mech.gm_compat->gmc_ ## name =  (_gss_##name##_t *)dlsym(so, "gssspi_" #name); \
 204         if (m->gm_mech.gm_compat->gmc_ ## name == gss_ ## name)         \
 205                 m->gm_mech.gm_compat->gmc_ ## name = NULL;              \
 206 } while (0)
 207
 208 /*
 209  *
 210  */
 211 static int
 212 add_builtin(gssapi_mech_interface mech)
 213 {
 214     struct _gss_mech_switch *m;
 215     OM_uint32 minor_status;
 216
 217     /* not registering any mech is ok */
 218     if (mech == NULL)
 219         return 0;
 220
 221     m = calloc(1, sizeof(*m));
 222     if (m == NULL)
 223         return ENOMEM;
 224     m->gm_so = NULL;
 225     m->gm_mech = *mech;
 226     _gss_intern_oid(&minor_status, &mech->gm_mech_oid, &m->gm_mech_oid);
 227     if (minor_status) {
 228         free(m);
 229         return minor_status;
 230     }
 231     gss_add_oid_set_member(&minor_status,
 232                            &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
 233
 234     /* pick up the oid sets of names */
 235
 236     if (m->gm_mech.gm_inquire_names_for_mech)
 237         (*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
 238             &m->gm_mech.gm_mech_oid, &m->gm_name_types);
 239
 240     if (m->gm_name_types == NULL)
 241         gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
 242
 243     HEIM_TAILQ_INSERT_TAIL(&_gss_mechs, m, gm_link);
 244     return 0;
 245 }
 246
 247 static void
 248 init_mech_switch_list(void *p)
 249 {
 250     struct _gss_mech_switch_list *mechs = p;
 251
 252     HEIM_TAILQ_INIT(mechs);
 253 }
 254
 255 /*
 256  * Load the mechanisms file (/etc/gss/mech).
 257  */
 258 void
 259 _gss_load_mech(void)
 260 {
 261         OM_uint32       major_status, minor_status;
 262         static heim_base_once_t once = HEIM_BASE_ONCE_INIT;
 263 #ifdef HAVE_DLOPEN
 264         FILE            *fp;
 265         char            buf[256];
 266         char            *p;
 267         char            *name, *oid, *lib, *kobj;
 268         struct _gss_mech_switch *m;
 269         void            *so;
 270         gss_OID         mech_oid;
 271         int             found;
 272         const char      *conf = secure_getenv("GSS_MECH_CONFIG");
 273 #endif
 274
 275         heim_base_once_f(&once, &_gss_mechs, init_mech_switch_list);
 276
 277         HEIMDAL_MUTEX_lock(&_gss_mech_mutex);
 278
 279         if (!HEIM_TAILQ_EMPTY(&_gss_mechs)) {
 280                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 281                 return;
 282         }
 283
 284         major_status = gss_create_empty_oid_set(&minor_status,
 285             &_gss_mech_oids);
 286         if (major_status) {
 287                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 288                 return;
 289         }
 290
 291         add_builtin(__gss_krb5_initialize());
 292         add_builtin(__gss_spnego_initialize());
 293         add_builtin(__gss_ntlm_initialize());
 294
 295 #ifdef HAVE_DLOPEN
 296         fp = fopen(conf ? conf : _PATH_GSS_MECH, "r");
 297         if (!fp)
 298                 goto out;
 299         rk_cloexec_file(fp);
 300
 301         while (fgets(buf, sizeof(buf), fp)) {
 302                 _gss_mo_init *mi;
 303
 304                 if (*buf == '#')
 305                         continue;
 306                 p = buf;
 307                 name = strsep(&p, "\t\n ");
 308                 if (p) while (isspace((unsigned char)*p)) p++;
 309                 oid = strsep(&p, "\t\n ");
 310                 if (p) while (isspace((unsigned char)*p)) p++;
 311                 lib = strsep(&p, "\t\n ");
 312                 if (p) while (isspace((unsigned char)*p)) p++;
 313                 kobj = strsep(&p, "\t\n ");
 314                 if (!name || !oid || !lib || !kobj)
 315                         continue;
 316
 317                 if (_gss_string_to_oid(oid, &mech_oid))
 318                         continue;
 319
 320                 /*
 321                  * Check for duplicates, already loaded mechs.
 322                  */
 323                 found = 0;
 324                 HEIM_TAILQ_FOREACH(m, &_gss_mechs, gm_link) {
 325                         if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech_oid)) {
 326                                 found = 1;
 327                                 break;
 328                         }
 329                 }
 330                 if (found)
 331                         continue;
 332
 333                 so = dlopen(lib, RTLD_LAZY | RTLD_LOCAL | RTLD_GROUP);
 334                 if (so == NULL) {
 335                         _gss_mg_log(1, "dlopen: %s\n", dlerror());
 336                         goto bad;
 337                 }
 338
 339                 m = calloc(1, sizeof(*m));
 340                 if (m == NULL)
 341                         goto bad;
 342
 343                 m->gm_so = so;
 344                 m->gm_mech_oid = mech_oid;
 345                 m->gm_mech.gm_name = strdup(name);
 346                 m->gm_mech.gm_mech_oid = *mech_oid;
 347                 m->gm_mech.gm_flags = 0;
 348                 m->gm_mech.gm_compat = calloc(1, sizeof(struct gss_mech_compat_desc_struct));
 349                 if (m->gm_mech.gm_compat == NULL)
 350                         goto bad;
 351
 352                 major_status = gss_add_oid_set_member(&minor_status,
 353                     &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
 354                 if (GSS_ERROR(major_status))
 355                         goto bad;
 356
 357                 SYM(acquire_cred);
 358                 SYM(release_cred);
 359                 SYM(init_sec_context);
 360                 SYM(accept_sec_context);
 361                 SYM(process_context_token);
 362                 SYM(delete_sec_context);
 363                 SYM(context_time);
 364                 SYM(get_mic);
 365                 SYM(verify_mic);
 366                 SYM(wrap);
 367                 SYM(unwrap);
 368                 OPTSYM(display_status);
 369                 OPTSYM(indicate_mechs);
 370                 SYM(compare_name);
 371                 SYM(display_name);
 372                 SYM(import_name);
 373                 SYM(export_name);
 374                 SYM(release_name);
 375                 OPTSYM(inquire_cred);
 376                 SYM(inquire_context);
 377                 SYM(wrap_size_limit);
 378                 OPTSYM(add_cred);
 379                 OPTSYM(inquire_cred_by_mech);
 380                 SYM(export_sec_context);
 381                 SYM(import_sec_context);
 382                 OPTSYM(inquire_names_for_mech);
 383                 OPTSYM(inquire_mechs_for_name);
 384                 SYM(canonicalize_name);
 385                 SYM(duplicate_name);
 386                 OPTSYM(inquire_cred_by_oid);
 387                 OPTSYM(inquire_sec_context_by_oid);
 388                 OPTSYM(set_sec_context_option);
 389                 OPTSPISYM(set_cred_option);
 390                 OPTSYM(pseudo_random);
 391                 OPTSYM(wrap_iov);
 392                 OPTSYM(unwrap_iov);
 393                 OPTSYM(wrap_iov_length);
 394                 OPTSYM(store_cred);
 395                 OPTSYM(export_cred);
 396                 OPTSYM(import_cred);
 397                 OPTSYM(acquire_cred_from);
 398                 OPTSYM(acquire_cred_impersonate_name);
 399 #if 0
 400                 OPTSYM(iter_creds);
 401                 OPTSYM(destroy_cred);
 402                 OPTSYM(cred_hold);
 403                 OPTSYM(cred_unhold);
 404                 OPTSYM(cred_label_get);
 405                 OPTSYM(cred_label_set);
 406 #endif
 407                 OPTSYM(display_name_ext);
 408                 OPTSYM(inquire_name);
 409                 OPTSYM(get_name_attribute);
 410                 OPTSYM(set_name_attribute);
 411                 OPTSYM(delete_name_attribute);
 412                 OPTSYM(export_name_composite);
 413                 OPTSYM(localname);
 414                 OPTSYM(duplicate_cred);
 415                 OPTSYM(add_cred_from);
 416                 OPTSYM(store_cred_into);
 417                 OPTSPISYM(authorize_localname);
 418                 OPTSPISPISYM(query_mechanism_info);
 419                 OPTSPISPISYM(query_meta_data);
 420                 OPTSPISPISYM(exchange_meta_data);
 421
 422                 mi = (_gss_mo_init *)dlsym(so, "gss_mo_init");
 423                 if (mi != NULL) {
 424                         major_status = mi(&minor_status, mech_oid,
 425                                           &m->gm_mech.gm_mo, &m->gm_mech.gm_mo_num);
 426                         if (GSS_ERROR(major_status))
 427                                 goto bad;
 428                 } else {
 429                         /* API-as-SPI compatibility */
 430                         COMPATSYM(inquire_saslname_for_mech);
 431                         COMPATSYM(inquire_mech_for_saslname);
 432                         COMPATSYM(inquire_attrs_for_mech);
 433                         COMPATSPISYM(acquire_cred_with_password);
 434                 }
 435
 436                 /* pick up the oid sets of names */
 437
 438                 if (m->gm_mech.gm_inquire_names_for_mech)
 439                         (*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
 440                         &m->gm_mech.gm_mech_oid, &m->gm_name_types);
 441
 442                 if (m->gm_name_types == NULL)
 443                         gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
 444
 445                 HEIM_TAILQ_INSERT_TAIL(&_gss_mechs, m, gm_link);
 446                 continue;
 447
 448         bad:
 449                 if (m != NULL) {
 450                         free(m->gm_mech.gm_compat);
 451                         /* do not free OID, it has been interned */
 452                         free((char *)m->gm_mech.gm_name);
 453                         free(m);
 454                 }
 455                 if (so != NULL)
 456                         dlclose(so);
 457                 continue;
 458         }
 459         fclose(fp);
 460
 461 out:
 462
 463 #endif
 464         add_builtin(__gss_sanon_initialize());
 465         HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 466 }
 467
 468 gssapi_mech_interface
 469 __gss_get_mechanism(gss_const_OID mech)
 470 {
 471         struct _gss_mech_switch *m;
 472
 473         _gss_load_mech();
 474         HEIM_TAILQ_FOREACH(m, &_gss_mechs, gm_link) {
 475                 if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
 476                         return &m->gm_mech;
 477         }
 478         return NULL;
 479 }
 480
 481 gss_OID
 482 _gss_mg_support_mechanism(gss_const_OID mech)
 483 {
 484         struct _gss_mech_switch *m;
 485
 486         _gss_load_mech();
 487         HEIM_TAILQ_FOREACH(m, &_gss_mechs, gm_link) {
 488                 if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
 489                         return m->gm_mech_oid;
 490         }
 491         return NULL;
 492 }
 493
 494 enum mech_name_match {
 495         MATCH_NONE = 0,
 496         MATCH_COMPLETE,
 497         MATCH_PARTIAL
 498 };
 499
 500 static enum mech_name_match
 501 match_mech_name(const char *gm_mech_name,
 502                 const char *name,
 503                 size_t namelen)
 504 {
 505         if (gm_mech_name == NULL)
 506                 return MATCH_NONE;
 507         else if (strcasecmp(gm_mech_name, name) == 0)
 508                 return MATCH_COMPLETE;
 509         else if (strncasecmp(gm_mech_name, name, namelen) == 0)
 510                 return MATCH_PARTIAL;
 511         else
 512                 return MATCH_NONE;
 513 }
 514
 515 /*
 516  * Return an OID for a built-in or dynamically loaded mechanism. For
 517  * API compatibility with previous versions, we treat "Kerberos 5"
 518  * as an alias for "krb5". Unique partial matches are supported.
 519  */
 520 GSSAPI_LIB_FUNCTION gss_OID GSSAPI_CALLCONV
 521 gss_name_to_oid(const char *name)
 522 {
 523         struct _gss_mech_switch *m, *partial = NULL;
 524         gss_OID oid = GSS_C_NO_OID;
 525         size_t namelen = strlen(name);
 526
 527         if (isdigit(name[0]) && _gss_string_to_oid(name, &oid) == 0)
 528                 return oid;
 529
 530         _gss_load_mech();
 531         HEIM_TAILQ_FOREACH(m, &_gss_mechs, gm_link) {
 532                 enum mech_name_match match;
 533
 534                 match = match_mech_name(m->gm_mech.gm_name, name, namelen);
 535                 if (match == MATCH_NONE &&
 536                     gss_oid_equal(m->gm_mech_oid, GSS_KRB5_MECHANISM))
 537                         match = match_mech_name("Kerberos 5", name, namelen);
 538
 539                 if (match == MATCH_COMPLETE)
 540                         return m->gm_mech_oid;
 541                 else if (match == MATCH_PARTIAL) {
 542                         if (partial)
 543                                 return NULL;
 544                         else
 545                                 partial = m;
 546                 }
 547         }
 548
 549         if (partial)
 550                 return partial->gm_mech_oid;
 551
 552         return NULL;
 553 }
 554
 555 GSSAPI_LIB_FUNCTION const char * GSSAPI_LIB_CALL
 556 gss_oid_to_name(gss_const_OID oid)
 557 {
 558         struct _gss_mech_switch *m;
 559
 560         _gss_load_mech();
 561         HEIM_TAILQ_FOREACH(m, &_gss_mechs, gm_link) {
 562                 if (gss_oid_equal(m->gm_mech_oid, oid))
 563                         return m->gm_mech.gm_name;
 564         }
 565
 566         return NULL;
 567 }
 568
 569 GSSAPI_LIB_FUNCTION uintptr_t GSSAPI_CALLCONV
 570 gss_get_instance(const char *libname)
 571 {
 572     static const char *instance = "libgssapi";
 573
 574     if (strcmp(libname, "gssapi") == 0)
 575         return (uintptr_t)instance;
 576     else if (strcmp(libname, "krb5") == 0)
 577         return krb5_get_instance(libname);
 578
 579     return 0;
 580 }