librpc/ndr/ndr_sec_helper.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    fast routines for getting the wire size of security objects
   5
   6    Copyright (C) Andrew Tridgell 2003
   7    Copyright (C) Stefan Metzmacher 2006-2008
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23
  24 #include "includes.h"
  25 #include "librpc/gen_ndr/ndr_security.h"
  26 #include "../libcli/security/security.h"
  27
  28
  29 /*
  30  * Find the wire size of a security_ace that has no trailing coda.
  31  * This is used in ndr_pull_security_ace() generated from security.idl
  32  * to work out where the coda starts (and in ndr_size_security_ace()
  33  * just below).
  34  */
  35 static size_t ndr_size_security_ace_core(const struct security_ace *ace, libndr_flags flags)
  36 {
  37         size_t ret;
  38
  39         if (!ace) return 0;
  40
  41         ret = 8 + ndr_size_dom_sid(&ace->trustee, flags);
  42         if (sec_ace_object(ace->type)) {
  43                 ret += 4; /* uint32 bitmap ace->object.object.flags */
  44                 if (ace->object.object.flags & SEC_ACE_OBJECT_TYPE_PRESENT) {
  45                         ret += 16; /* GUID ace->object.object.type.type */
  46                 }
  47                 if (ace->object.object.flags & SEC_ACE_INHERITED_OBJECT_TYPE_PRESENT) {
  48                         ret += 16; /* GUID ace->object.object.inherited_type.inherited_type */
  49                 }
  50         }
  51
  52         return ret;
  53 }
  54
  55 /*
  56   return the wire size of a security_ace
  57 */
  58 size_t ndr_size_security_ace(const struct security_ace *ace, libndr_flags flags)
  59 {
  60         size_t base = ndr_size_security_ace_core(ace, flags);
  61         size_t ret = base;
  62         if (sec_ace_callback(ace->type)) {
  63                 ret += ace->coda.conditions.length;
  64         } else if (ace->type == SEC_ACE_TYPE_SYSTEM_RESOURCE_ATTRIBUTE) {
  65                 ret += ndr_size_security_ace_coda(&ace->coda, ace->type, flags);
  66         } else {
  67                 /*
  68                  * Normal ACEs have a coda.ignored blob that is always or
  69                  * almost always empty. We aren't going to push it (it is
  70                  * ignored), so we don't add that length to the size.
  71                  */
  72         }
  73         /* round up to a multiple of 4  (MS-DTYP 2.4.4.1) */
  74         ret = (ret + 3ULL) & ~3ULL;
  75         if (unlikely(ret < base)) {
  76                 /* overflow, and there's not much we can do anyway */
  77                 return 0;
  78         }
  79         return ret;
  80 }
  81
  82
  83 static inline enum ndr_err_code ndr_maybe_pull_security_ace_object_ctr(struct ndr_pull *ndr,
  84                                                                        ndr_flags_type ndr_flags,
  85                                                                        struct security_ace *r)
  86 {
  87         /*
  88          * If this is not an object ACE (as is usually common),
  89          * ndr_pull_security_ace_object_ctr() will do nothing.
  90          *
  91          * By avoiding calling the function in that case, we avoid some
  92          * tallocing and ndr token busywork.
  93          */
  94         bool is_object = sec_ace_object(r->type);
  95         if (is_object) {
  96                 NDR_CHECK(ndr_pull_set_switch_value(ndr, &r->object, is_object));
  97                 NDR_CHECK(ndr_pull_security_ace_object_ctr(ndr, ndr_flags, &r->object));
  98         }
  99         return NDR_ERR_SUCCESS;
 100 }
 101
 102
 103 _PUBLIC_ enum ndr_err_code ndr_pull_security_ace(struct ndr_pull *ndr, ndr_flags_type ndr_flags, struct security_ace *r)
 104 {
 105         NDR_PULL_CHECK_FLAGS(ndr, ndr_flags);
 106         if (ndr_flags & NDR_SCALARS) {
 107                 NDR_CHECK(ndr_pull_align(ndr, 5));
 108                 NDR_CHECK(ndr_pull_security_ace_type(ndr, NDR_SCALARS, &r->type));
 109                 NDR_CHECK(ndr_pull_security_ace_flags(ndr, NDR_SCALARS, &r->flags));
 110                 NDR_CHECK(ndr_pull_uint16(ndr, NDR_SCALARS, &r->size));
 111                 NDR_CHECK(ndr_pull_uint32(ndr, NDR_SCALARS, &r->access_mask));
 112                 NDR_CHECK(ndr_maybe_pull_security_ace_object_ctr(ndr, NDR_SCALARS, r));
 113                 NDR_CHECK(ndr_pull_dom_sid(ndr, NDR_SCALARS, &r->trustee));
 114                 if (!sec_ace_has_extra_blob(r->type)) {
 115                         r->coda.ignored.data = NULL;
 116                         r->coda.ignored.length = 0;
 117                 } else {
 118                         struct ndr_pull *_ndr_coda;
 119                         ssize_t sub_size = ndr_subcontext_size_of_ace_coda(r, r->size, ndr->flags);
 120                         NDR_CHECK(ndr_pull_subcontext_start(ndr, &_ndr_coda, 0, sub_size));
 121                         NDR_CHECK(ndr_pull_set_switch_value(_ndr_coda, &r->coda, r->type));
 122                         NDR_CHECK(ndr_pull_security_ace_coda(_ndr_coda, NDR_SCALARS|NDR_BUFFERS, &r->coda));
 123                         NDR_CHECK(ndr_pull_subcontext_end(ndr, _ndr_coda, 0, sub_size));
 124                 }
 125                 NDR_CHECK(ndr_pull_trailer_align(ndr, 5));
 126         }
 127         if (ndr_flags & NDR_BUFFERS) {
 128                 NDR_CHECK(ndr_maybe_pull_security_ace_object_ctr(ndr, NDR_BUFFERS, r));
 129         }
 130         return NDR_ERR_SUCCESS;
 131 }
 132
 133
 134 static inline enum ndr_err_code ndr_maybe_push_security_ace_object_ctr(struct ndr_push *ndr,
 135                                                                        ndr_flags_type ndr_flags,
 136                                                                        const struct security_ace *r)
 137 {
 138         /*
 139          * ndr_push_security_ace_object_ctr() does nothing (except tallocing
 140          * and ndr_token fiddling) unless the ACE is an object ACE, which is
 141          * usually very unlikely.
 142          */
 143         bool is_object = sec_ace_object(r->type);
 144         if (is_object) {
 145                 NDR_CHECK(ndr_push_set_switch_value(ndr, &r->object, is_object));
 146                 NDR_CHECK(ndr_push_security_ace_object_ctr(ndr, ndr_flags, &r->object));
 147         }
 148         return NDR_ERR_SUCCESS;
 149 }
 150
 151 _PUBLIC_ enum ndr_err_code ndr_push_security_ace(struct ndr_push *ndr, ndr_flags_type ndr_flags, const struct security_ace *r)
 152 {
 153         NDR_PUSH_CHECK_FLAGS(ndr, ndr_flags);
 154         if (ndr_flags & NDR_SCALARS) {
 155                 NDR_CHECK(ndr_push_align(ndr, 5));
 156                 NDR_CHECK(ndr_push_security_ace_type(ndr, NDR_SCALARS, r->type));
 157                 NDR_CHECK(ndr_push_security_ace_flags(ndr, NDR_SCALARS, r->flags));
 158                 NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, ndr_size_security_ace(r, ndr->flags)));
 159                 NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, r->access_mask));
 160                 NDR_CHECK(ndr_maybe_push_security_ace_object_ctr(ndr, NDR_SCALARS, r));
 161                 NDR_CHECK(ndr_push_dom_sid(ndr, NDR_SCALARS, &r->trustee));
 162                 if (sec_ace_has_extra_blob(r->type)) {
 163                         struct ndr_push *_ndr_coda;
 164                         size_t coda_size = ndr_subcontext_size_of_ace_coda(
 165                                 r,
 166                                 ndr_size_security_ace(r, ndr->flags),
 167                                 ndr->flags);
 168                         NDR_CHECK(ndr_push_subcontext_start(ndr, &_ndr_coda, 0, coda_size));
 169                         NDR_CHECK(ndr_push_set_switch_value(_ndr_coda, &r->coda, r->type));
 170                         NDR_CHECK(ndr_push_security_ace_coda(_ndr_coda, NDR_SCALARS|NDR_BUFFERS, &r->coda));
 171                         NDR_CHECK(ndr_push_subcontext_end(ndr, _ndr_coda, 0, coda_size));
 172                 }
 173                 NDR_CHECK(ndr_push_trailer_align(ndr, 5));
 174         }
 175         if (ndr_flags & NDR_BUFFERS) {
 176                 NDR_CHECK(ndr_maybe_push_security_ace_object_ctr(ndr, NDR_BUFFERS, r));
 177         }
 178         return NDR_ERR_SUCCESS;
 179 }
 180
 181
 182 /*
 183  * An ACE coda can't be bigger than the space allowed for by
 184  * ace->size, so we need to check this from the context of the ACE.
 185  *
 186  * Usually the coda also can't be any smaller than the remaining
 187  * space, because it is defined as a blob consuming everything it can.
 188  *
 189  * This is only used to find the size for the coda subcontext in
 190  * security.idl.
 191  */
 192 size_t ndr_subcontext_size_of_ace_coda(const struct security_ace *ace,
 193                                        size_t ace_size,
 194                                        libndr_flags flags)
 195 {
 196         size_t core_size;
 197         if (ace_size == 0) {
 198                 return 0;
 199         }
 200         core_size = ndr_size_security_ace_core(ace, flags);
 201         if (ace_size < core_size) {
 202                 return 0;
 203         }
 204         return ace_size - core_size;
 205 }
 206
 207 /*
 208   return the wire size of a security_acl
 209 */
 210 size_t ndr_size_security_acl(const struct security_acl *theacl, libndr_flags flags)
 211 {
 212         size_t ret;
 213         uint32_t i;
 214         if (!theacl) return 0;
 215         ret = 8;
 216         for (i=0;i<theacl->num_aces;i++) {
 217                 ret += ndr_size_security_ace(&theacl->aces[i], flags);
 218         }
 219         return ret;
 220 }
 221
 222 /*
 223   return the wire size of a security descriptor
 224 */
 225 size_t ndr_size_security_descriptor(const struct security_descriptor *sd, libndr_flags flags)
 226 {
 227         size_t ret;
 228         if (!sd) return 0;
 229
 230         ret = 20;
 231         ret += ndr_size_dom_sid(sd->owner_sid, flags);
 232         ret += ndr_size_dom_sid(sd->group_sid, flags);
 233         ret += ndr_size_security_acl(sd->dacl, flags);
 234         ret += ndr_size_security_acl(sd->sacl, flags);
 235         return ret;
 236 }
 237
 238 /*
 239   return the wire size of a dom_sid
 240 */
 241 size_t ndr_size_dom_sid(const struct dom_sid *sid, libndr_flags flags)
 242 {
 243         if (!sid) return 0;
 244         return 8 + 4*sid->num_auths;
 245 }
 246
 247 size_t ndr_size_dom_sid28(const struct dom_sid *sid, libndr_flags flags)
 248 {
 249         if (all_zero((const uint8_t *)sid, sizeof(struct dom_sid))) {
 250                 return 0;
 251         }
 252         return ndr_size_dom_sid(sid, flags);
 253 }
 254
 255 size_t ndr_size_dom_sid0(const struct dom_sid *sid, libndr_flags flags)
 256 {
 257         return ndr_size_dom_sid28(sid, flags);
 258 }
 259
 260 /*
 261   print a dom_sid
 262 */
 263 void ndr_print_dom_sid(struct ndr_print *ndr, const char *name, const struct dom_sid *sid)
 264 {
 265         struct dom_sid_buf buf;
 266         ndr->print(ndr, "%-25s: %s", name, dom_sid_str_buf(sid, &buf));
 267 }
 268
 269 void ndr_print_dom_sid2(struct ndr_print *ndr, const char *name, const struct dom_sid *sid)
 270 {
 271         ndr_print_dom_sid(ndr, name, sid);
 272 }
 273
 274 void ndr_print_dom_sid28(struct ndr_print *ndr, const char *name, const struct dom_sid *sid)
 275 {
 276         ndr_print_dom_sid(ndr, name, sid);
 277 }
 278
 279 void ndr_print_dom_sid0(struct ndr_print *ndr, const char *name, const struct dom_sid *sid)
 280 {
 281         ndr_print_dom_sid(ndr, name, sid);
 282 }
 283
 284
 285 /*
 286   parse a dom_sid2 - this is a dom_sid but with an extra copy of the num_auths field
 287 */
 288 enum ndr_err_code ndr_pull_dom_sid2(struct ndr_pull *ndr, ndr_flags_type ndr_flags, struct dom_sid *sid)
 289 {
 290         uint32_t num_auths;
 291         if (!(ndr_flags & NDR_SCALARS)) {
 292                 return NDR_ERR_SUCCESS;
 293         }
 294         NDR_CHECK(ndr_pull_uint3264(ndr, NDR_SCALARS, &num_auths));
 295         NDR_CHECK(ndr_pull_dom_sid(ndr, ndr_flags, sid));
 296         if (sid->num_auths != num_auths) {
 297                 return ndr_pull_error(ndr, NDR_ERR_ARRAY_SIZE,
 298                                       "Bad num_auths %"PRIu32"; should equal %"PRId8,
 299                                       num_auths, sid->num_auths);
 300         }
 301         return NDR_ERR_SUCCESS;
 302 }
 303
 304 /*
 305   parse a dom_sid2 - this is a dom_sid but with an extra copy of the num_auths field
 306 */
 307 enum ndr_err_code ndr_push_dom_sid2(struct ndr_push *ndr, ndr_flags_type ndr_flags, const struct dom_sid *sid)
 308 {
 309         if (!(ndr_flags & NDR_SCALARS)) {
 310                 return NDR_ERR_SUCCESS;
 311         }
 312         NDR_CHECK(ndr_push_uint3264(ndr, NDR_SCALARS, sid->num_auths));
 313         return ndr_push_dom_sid(ndr, ndr_flags, sid);
 314 }
 315
 316 /*
 317   parse a dom_sid28 - this is a dom_sid in a fixed 28 byte buffer, so we need to ensure there are only up to 5 sub_auth
 318 */
 319 enum ndr_err_code ndr_pull_dom_sid28(struct ndr_pull *ndr, ndr_flags_type ndr_flags, struct dom_sid *sid)
 320 {
 321         enum ndr_err_code status;
 322         struct ndr_pull *subndr;
 323
 324         if (!(ndr_flags & NDR_SCALARS)) {
 325                 return NDR_ERR_SUCCESS;
 326         }
 327
 328         subndr = talloc_zero(ndr, struct ndr_pull);
 329         NDR_ERR_HAVE_NO_MEMORY(subndr);
 330         subndr->flags           = ndr->flags;
 331         subndr->current_mem_ctx = ndr->current_mem_ctx;
 332
 333         subndr->data            = ndr->data + ndr->offset;
 334         subndr->data_size       = 28;
 335         subndr->offset          = 0;
 336
 337         status = ndr_pull_advance(ndr, 28);
 338         if (!NDR_ERR_CODE_IS_SUCCESS(status)) {
 339                 TALLOC_FREE(subndr);
 340                 return status;
 341         }
 342
 343         status = ndr_pull_dom_sid(subndr, ndr_flags, sid);
 344         if (!NDR_ERR_CODE_IS_SUCCESS(status)) {
 345                 /* handle a w2k bug which send random data in the buffer */
 346                 ZERO_STRUCTP(sid);
 347         } else if (sid->num_auths == 0) {
 348                 ZERO_STRUCT(sid->sub_auths);
 349         }
 350
 351         TALLOC_FREE(subndr);
 352         return NDR_ERR_SUCCESS;
 353 }
 354
 355 /*
 356   push a dom_sid28 - this is a dom_sid in a 28 byte fixed buffer
 357 */
 358 enum ndr_err_code ndr_push_dom_sid28(struct ndr_push *ndr, ndr_flags_type ndr_flags, const struct dom_sid *sid)
 359 {
 360         uint32_t old_offset;
 361         uint32_t padding;
 362
 363         if (!(ndr_flags & NDR_SCALARS)) {
 364                 return NDR_ERR_SUCCESS;
 365         }
 366
 367         if (sid->num_auths > 5) {
 368                 return ndr_push_error(ndr, NDR_ERR_RANGE,
 369                                       "dom_sid28 allows only up to 5 sub auths [%"PRId8"]",
 370                                       sid->num_auths);
 371         }
 372
 373         old_offset = ndr->offset;
 374         NDR_CHECK(ndr_push_dom_sid(ndr, ndr_flags, sid));
 375
 376         padding = 28 - (ndr->offset - old_offset);
 377
 378         if (padding > 0) {
 379                 NDR_CHECK(ndr_push_zero(ndr, padding));
 380         }
 381
 382         return NDR_ERR_SUCCESS;
 383 }
 384
 385 /*
 386   parse a dom_sid0 - this is a dom_sid in a variable byte buffer, which is maybe empty
 387 */
 388 enum ndr_err_code ndr_pull_dom_sid0(struct ndr_pull *ndr, ndr_flags_type ndr_flags, struct dom_sid *sid)
 389 {
 390         if (!(ndr_flags & NDR_SCALARS)) {
 391                 return NDR_ERR_SUCCESS;
 392         }
 393
 394         if (ndr->data_size == ndr->offset) {
 395                 ZERO_STRUCTP(sid);
 396                 return NDR_ERR_SUCCESS;
 397         }
 398
 399         return ndr_pull_dom_sid(ndr, ndr_flags, sid);
 400 }
 401
 402 /*
 403   push a dom_sid0 - this is a dom_sid in a variable byte buffer, which is maybe empty
 404 */
 405 enum ndr_err_code ndr_push_dom_sid0(struct ndr_push *ndr, ndr_flags_type ndr_flags, const struct dom_sid *sid)
 406 {
 407         if (!(ndr_flags & NDR_SCALARS)) {
 408                 return NDR_ERR_SUCCESS;
 409         }
 410
 411         if (!sid) {
 412                 return NDR_ERR_SUCCESS;
 413         }
 414
 415         if (all_zero((const uint8_t *)sid, sizeof(struct dom_sid))) {
 416                 return NDR_ERR_SUCCESS;
 417         }
 418
 419         return ndr_push_dom_sid(ndr, ndr_flags, sid);
 420 }
 421
 422 _PUBLIC_ enum ndr_err_code ndr_push_dom_sid(struct ndr_push *ndr, ndr_flags_type ndr_flags, const struct dom_sid *r)
 423 {
 424         uint32_t cntr_sub_auths_0;
 425         if (ndr_flags & NDR_SCALARS) {
 426                 NDR_CHECK(ndr_push_align(ndr, 4));
 427                 NDR_CHECK(ndr_push_uint8(ndr, NDR_SCALARS, r->sid_rev_num));
 428                 NDR_CHECK(ndr_push_int8(ndr, NDR_SCALARS, r->num_auths));
 429                 NDR_CHECK(ndr_push_array_uint8(ndr, NDR_SCALARS, r->id_auth, 6));
 430                 if (r->num_auths < 0 || r->num_auths > ARRAY_SIZE(r->sub_auths)) {
 431                         return ndr_push_error(ndr, NDR_ERR_RANGE, "value (%"PRId8") out of range (0 - %zu)", r->num_auths, ARRAY_SIZE(r->sub_auths));
 432                 }
 433                 for (cntr_sub_auths_0 = 0; cntr_sub_auths_0 < r->num_auths; cntr_sub_auths_0++) {
 434                         NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, r->sub_auths[cntr_sub_auths_0]));
 435                 }
 436         }
 437         return NDR_ERR_SUCCESS;
 438 }
 439
 440 _PUBLIC_ enum ndr_err_code ndr_pull_dom_sid(struct ndr_pull *ndr, ndr_flags_type ndr_flags, struct dom_sid *r)
 441 {
 442         uint32_t cntr_sub_auths_0;
 443         if (ndr_flags & NDR_SCALARS) {
 444                 NDR_CHECK(ndr_pull_align(ndr, 4));
 445                 NDR_CHECK(ndr_pull_uint8(ndr, NDR_SCALARS, &r->sid_rev_num));
 446                 NDR_CHECK(ndr_pull_int8(ndr, NDR_SCALARS, &r->num_auths));
 447                 if (r->num_auths < 0 || r->num_auths > ARRAY_SIZE(r->sub_auths)) {
 448                         return ndr_pull_error(ndr, NDR_ERR_RANGE, "value (%"PRId8") out of range (0 - %zu)", r->num_auths, ARRAY_SIZE(r->sub_auths));
 449                 }
 450                 NDR_CHECK(ndr_pull_array_uint8(ndr, NDR_SCALARS, r->id_auth, 6));
 451                 ZERO_STRUCT(r->sub_auths);
 452                 for (cntr_sub_auths_0 = 0; cntr_sub_auths_0 < r->num_auths; cntr_sub_auths_0++) {
 453                         NDR_CHECK(ndr_pull_uint32(ndr, NDR_SCALARS, &r->sub_auths[cntr_sub_auths_0]));
 454                 }
 455         }
 456         return NDR_ERR_SUCCESS;
 457 }