source4/libcli/security/sddl.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    security descriptor description language functions
   5
   6    Copyright (C) Andrew Tridgell                2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "libcli/security/security.h"
  24 #include "librpc/gen_ndr/ndr_misc.h"
  25 #include "system/locale.h"
  26
  27 struct flag_map {
  28         const char *name;
  29         uint32_t flag;
  30 };
  31
  32 /*
  33   map a series of letter codes into a uint32_t
  34 */
  35 static bool sddl_map_flags(const struct flag_map *map, const char *str,
  36                            uint32_t *flags, size_t *len)
  37 {
  38         const char *str0 = str;
  39         if (len) *len = 0;
  40         *flags = 0;
  41         while (str[0] && isupper(str[0])) {
  42                 int i;
  43                 for (i=0;map[i].name;i++) {
  44                         size_t l = strlen(map[i].name);
  45                         if (strncmp(map[i].name, str, l) == 0) {
  46                                 *flags |= map[i].flag;
  47                                 str += l;
  48                                 if (len) *len += l;
  49                                 break;
  50                         }
  51                 }
  52                 if (map[i].name == NULL) {
  53                         DEBUG(1, ("Unknown flag - %s in %s\n", str, str0));
  54                         return false;
  55                 }
  56         }
  57         return true;
  58 }
  59
  60 /*
  61   a mapping between the 2 letter SID codes and sid strings
  62 */
  63 static const struct {
  64         const char *code;
  65         const char *sid;
  66         uint32_t rid;
  67 } sid_codes[] = {
  68         { "AO", SID_BUILTIN_ACCOUNT_OPERATORS },
  69         { "BA", SID_BUILTIN_ADMINISTRATORS },
  70         { "RU", SID_BUILTIN_PREW2K },
  71         { "PO", SID_BUILTIN_PRINT_OPERATORS },
  72         { "RS", SID_BUILTIN_RAS_SERVERS },
  73
  74         { "AU", SID_NT_AUTHENTICATED_USERS },
  75         { "SY", SID_NT_SYSTEM },
  76         { "PS", SID_NT_SELF },
  77         { "WD", SID_WORLD },
  78         { "ED", SID_NT_ENTERPRISE_DCS },
  79
  80         { "CO", SID_CREATOR_OWNER },
  81         { "CG", SID_CREATOR_GROUP },
  82
  83         { "DA", NULL, DOMAIN_RID_ADMINS },
  84         { "EA", NULL, DOMAIN_RID_ENTERPRISE_ADMINS },
  85         { "DD", NULL, DOMAIN_RID_DCS },
  86         { "DU", NULL, DOMAIN_RID_USERS },
  87         { "CA", NULL, DOMAIN_RID_CERT_ADMINS },
  88 };
  89
  90 /*
  91   decode a SID
  92   It can either be a special 2 letter code, or in S-* format
  93 */
  94 static struct dom_sid *sddl_decode_sid(TALLOC_CTX *mem_ctx, const char **sddlp,
  95                                        const struct dom_sid *domain_sid)
  96 {
  97         const char *sddl = (*sddlp);
  98         int i;
  99
 100         /* see if its in the numeric format */
 101         if (strncmp(sddl, "S-", 2) == 0) {
 102                 struct dom_sid *sid;
 103                 char *sid_str;
 104                 size_t len = strspn(sddl+2, "-0123456789");
 105                 sid_str = talloc_strndup(mem_ctx, sddl, len+2);
 106                 if (!sid_str) {
 107                         return NULL;
 108                 }
 109                 (*sddlp) += len+2;
 110                 sid = dom_sid_parse_talloc(mem_ctx, sid_str);
 111                 talloc_free(sid_str);
 112                 return sid;
 113         }
 114
 115         /* now check for one of the special codes */
 116         for (i=0;i<ARRAY_SIZE(sid_codes);i++) {
 117                 if (strncmp(sid_codes[i].code, sddl, 2) == 0) break;
 118         }
 119         if (i == ARRAY_SIZE(sid_codes)) {
 120                 DEBUG(1,("Unknown sddl sid code '%2.2s'\n", sddl));
 121                 return NULL;
 122         }
 123
 124         (*sddlp) += 2;
 125
 126         if (sid_codes[i].sid == NULL) {
 127                 return dom_sid_add_rid(mem_ctx, domain_sid, sid_codes[i].rid);
 128         }
 129
 130         return dom_sid_parse_talloc(mem_ctx, sid_codes[i].sid);
 131 }
 132
 133 static const struct flag_map ace_types[] = {
 134         { "AU", SEC_ACE_TYPE_SYSTEM_AUDIT },
 135         { "AL", SEC_ACE_TYPE_SYSTEM_ALARM },
 136         { "OA", SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT },
 137         { "OD", SEC_ACE_TYPE_ACCESS_DENIED_OBJECT },
 138         { "OU", SEC_ACE_TYPE_SYSTEM_AUDIT_OBJECT },
 139         { "OL", SEC_ACE_TYPE_SYSTEM_ALARM_OBJECT },
 140         { "A",  SEC_ACE_TYPE_ACCESS_ALLOWED },
 141         { "D",  SEC_ACE_TYPE_ACCESS_DENIED },
 142         { NULL, 0 }
 143 };
 144
 145 static const struct flag_map ace_flags[] = {
 146         { "OI", SEC_ACE_FLAG_OBJECT_INHERIT },
 147         { "CI", SEC_ACE_FLAG_CONTAINER_INHERIT },
 148         { "NP", SEC_ACE_FLAG_NO_PROPAGATE_INHERIT },
 149         { "IO", SEC_ACE_FLAG_INHERIT_ONLY },
 150         { "ID", SEC_ACE_FLAG_INHERITED_ACE },
 151         { "SA", SEC_ACE_FLAG_SUCCESSFUL_ACCESS },
 152         { "FA", SEC_ACE_FLAG_FAILED_ACCESS },
 153         { NULL, 0 },
 154 };
 155
 156 static const struct flag_map ace_access_mask[] = {
 157         { "RP", SEC_ADS_READ_PROP },
 158         { "WP", SEC_ADS_WRITE_PROP },
 159         { "CR", SEC_ADS_CONTROL_ACCESS },
 160         { "CC", SEC_ADS_CREATE_CHILD },
 161         { "DC", SEC_ADS_DELETE_CHILD },
 162         { "LC", SEC_ADS_LIST },
 163         { "LO", SEC_ADS_LIST_OBJECT },
 164         { "RC", SEC_STD_READ_CONTROL },
 165         { "WO", SEC_STD_WRITE_OWNER },
 166         { "WD", SEC_STD_WRITE_DAC },
 167         { "SD", SEC_STD_DELETE },
 168         { "DT", SEC_ADS_DELETE_TREE },
 169         { "SW", SEC_ADS_SELF_WRITE },
 170         { "GA", SEC_GENERIC_ALL },
 171         { "GR", SEC_GENERIC_READ },
 172         { "GW", SEC_GENERIC_WRITE },
 173         { "GX", SEC_GENERIC_EXECUTE },
 174         { NULL, 0 }
 175 };
 176
 177 /*
 178   decode an ACE
 179   return true on success, false on failure
 180   note that this routine modifies the string
 181 */
 182 static bool sddl_decode_ace(TALLOC_CTX *mem_ctx, struct security_ace *ace, char *str,
 183                             const struct dom_sid *domain_sid)
 184 {
 185         const char *tok[6];
 186         const char *s;
 187         int i;
 188         uint32_t v;
 189         struct dom_sid *sid;
 190
 191         ZERO_STRUCTP(ace);
 192
 193         /* parse out the 6 tokens */
 194         tok[0] = str;
 195         for (i=0;i<5;i++) {
 196                 char *ptr = strchr(str, ';');
 197                 if (ptr == NULL) return false;
 198                 *ptr = 0;
 199                 str = ptr+1;
 200                 tok[i+1] = str;
 201         }
 202
 203         /* parse ace type */
 204         if (!sddl_map_flags(ace_types, tok[0], &v, NULL)) {
 205                 return false;
 206         }
 207         ace->type = v;
 208
 209         /* ace flags */
 210         if (!sddl_map_flags(ace_flags, tok[1], &v, NULL)) {
 211                 return false;
 212         }
 213         ace->flags = v;
 214
 215         /* access mask */
 216         if (strncmp(tok[2], "0x", 2) == 0) {
 217                 ace->access_mask = strtol(tok[2], NULL, 16);
 218         } else {
 219                 if (!sddl_map_flags(ace_access_mask, tok[2], &v, NULL)) {
 220                         return false;
 221                 }
 222                 ace->access_mask = v;
 223         }
 224
 225         /* object */
 226         if (tok[3][0] != 0) {
 227                 NTSTATUS status = GUID_from_string(tok[3],
 228                                                    &ace->object.object.type.type);
 229                 if (!NT_STATUS_IS_OK(status)) {
 230                         return false;
 231                 }
 232                 ace->object.object.flags |= SEC_ACE_OBJECT_TYPE_PRESENT;
 233         }
 234
 235         /* inherit object */
 236         if (tok[4][0] != 0) {
 237                 NTSTATUS status = GUID_from_string(tok[4],
 238                                                    &ace->object.object.inherited_type.inherited_type);
 239                 if (!NT_STATUS_IS_OK(status)) {
 240                         return false;
 241                 }
 242                 ace->object.object.flags |= SEC_ACE_INHERITED_OBJECT_TYPE_PRESENT;
 243         }
 244
 245         /* trustee */
 246         s = tok[5];
 247         sid = sddl_decode_sid(mem_ctx, &s, domain_sid);
 248         if (sid == NULL) {
 249                 return false;
 250         }
 251         ace->trustee = *sid;
 252         talloc_free(sid);
 253
 254         return true;
 255 }
 256
 257 static const struct flag_map acl_flags[] = {
 258         { "P", SEC_DESC_DACL_PROTECTED },
 259         { "AR", SEC_DESC_DACL_AUTO_INHERIT_REQ },
 260         { "AI", SEC_DESC_DACL_AUTO_INHERITED },
 261         { NULL, 0 }
 262 };
 263
 264 /*
 265   decode an ACL
 266 */
 267 static struct security_acl *sddl_decode_acl(struct security_descriptor *sd,
 268                                             const char **sddlp, uint32_t *flags,
 269                                             const struct dom_sid *domain_sid)
 270 {
 271         const char *sddl = *sddlp;
 272         struct security_acl *acl;
 273         size_t len;
 274
 275         *flags = 0;
 276
 277         acl = talloc_zero(sd, struct security_acl);
 278         if (acl == NULL) return NULL;
 279         acl->revision = SECURITY_ACL_REVISION_NT4;
 280
 281         if (isupper(sddl[0]) && sddl[1] == ':') {
 282                 /* its an empty ACL */
 283                 return acl;
 284         }
 285
 286         /* work out the ACL flags */
 287         if (!sddl_map_flags(acl_flags, sddl, flags, &len)) {
 288                 talloc_free(acl);
 289                 return NULL;
 290         }
 291         sddl += len;
 292
 293         /* now the ACEs */
 294         while (*sddl == '(') {
 295                 char *astr;
 296                 len = strcspn(sddl+1, ")");
 297                 astr = talloc_strndup(acl, sddl+1, len);
 298                 if (astr == NULL || sddl[len+1] != ')') {
 299                         talloc_free(acl);
 300                         return NULL;
 301                 }
 302                 acl->aces = talloc_realloc(acl, acl->aces, struct security_ace,
 303                                            acl->num_aces+1);
 304                 if (acl->aces == NULL) {
 305                         talloc_free(acl);
 306                         return NULL;
 307                 }
 308                 if (!sddl_decode_ace(acl->aces, &acl->aces[acl->num_aces],
 309                                      astr, domain_sid)) {
 310                         talloc_free(acl);
 311                         return NULL;
 312                 }
 313                 switch (acl->aces[acl->num_aces].type) {
 314                 case SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT:
 315                 case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
 316                 case SEC_ACE_TYPE_SYSTEM_AUDIT_OBJECT:
 317                 case SEC_ACE_TYPE_SYSTEM_ALARM_OBJECT:
 318                         acl->revision = SECURITY_ACL_REVISION_ADS;
 319                         break;
 320                 default:
 321                         break;
 322                 }
 323                 talloc_free(astr);
 324                 sddl += len+2;
 325                 acl->num_aces++;
 326         }
 327
 328         (*sddlp) = sddl;
 329         return acl;
 330 }
 331
 332 /*
 333   decode a security descriptor in SDDL format
 334 */
 335 struct security_descriptor *sddl_decode(TALLOC_CTX *mem_ctx, const char *sddl,
 336                                         const struct dom_sid *domain_sid)
 337 {
 338         struct security_descriptor *sd;
 339         sd = talloc_zero(mem_ctx, struct security_descriptor);
 340
 341         sd->revision = SECURITY_DESCRIPTOR_REVISION_1;
 342         sd->type     = SEC_DESC_SELF_RELATIVE;
 343
 344         while (*sddl) {
 345                 uint32_t flags;
 346                 char c = sddl[0];
 347                 if (sddl[1] != ':') goto failed;
 348
 349                 sddl += 2;
 350                 switch (c) {
 351                 case 'D':
 352                         if (sd->dacl != NULL) goto failed;
 353                         sd->dacl = sddl_decode_acl(sd, &sddl, &flags, domain_sid);
 354                         if (sd->dacl == NULL) goto failed;
 355                         sd->type |= flags | SEC_DESC_DACL_PRESENT;
 356                         break;
 357                 case 'S':
 358                         if (sd->sacl != NULL) goto failed;
 359                         sd->sacl = sddl_decode_acl(sd, &sddl, &flags, domain_sid);
 360                         if (sd->sacl == NULL) goto failed;
 361                         /* this relies on the SEC_DESC_SACL_* flags being
 362                            1 bit shifted from the SEC_DESC_DACL_* flags */
 363                         sd->type |= (flags<<1) | SEC_DESC_SACL_PRESENT;
 364                         break;
 365                 case 'O':
 366                         if (sd->owner_sid != NULL) goto failed;
 367                         sd->owner_sid = sddl_decode_sid(sd, &sddl, domain_sid);
 368                         if (sd->owner_sid == NULL) goto failed;
 369                         break;
 370                 case 'G':
 371                         if (sd->group_sid != NULL) goto failed;
 372                         sd->group_sid = sddl_decode_sid(sd, &sddl, domain_sid);
 373                         if (sd->group_sid == NULL) goto failed;
 374                         break;
 375                 }
 376         }
 377
 378         return sd;
 379
 380 failed:
 381         DEBUG(2,("Badly formatted SDDL '%s'\n", sddl));
 382         talloc_free(sd);
 383         return NULL;
 384 }
 385
 386 /*
 387   turn a set of flags into a string
 388 */
 389 static char *sddl_flags_to_string(TALLOC_CTX *mem_ctx, const struct flag_map *map,
 390                                   uint32_t flags, bool check_all)
 391 {
 392         int i;
 393         char *s;
 394
 395         /* try to find an exact match */
 396         for (i=0;map[i].name;i++) {
 397                 if (map[i].flag == flags) {
 398                         return talloc_strdup(mem_ctx, map[i].name);
 399                 }
 400         }
 401
 402         s = talloc_strdup(mem_ctx, "");
 403
 404         /* now by bits */
 405         for (i=0;map[i].name;i++) {
 406                 if ((flags & map[i].flag) != 0) {
 407                         s = talloc_asprintf_append_buffer(s, "%s", map[i].name);
 408                         if (s == NULL) goto failed;
 409                         flags &= ~map[i].flag;
 410                 }
 411         }
 412
 413         if (check_all && flags != 0) {
 414                 goto failed;
 415         }
 416
 417         return s;
 418
 419 failed:
 420         talloc_free(s);
 421         return NULL;
 422 }
 423
 424 /*
 425   encode a sid in SDDL format
 426 */
 427 static char *sddl_encode_sid(TALLOC_CTX *mem_ctx, const struct dom_sid *sid,
 428                              const struct dom_sid *domain_sid)
 429 {
 430         int i;
 431         char *sidstr;
 432
 433         sidstr = dom_sid_string(mem_ctx, sid);
 434         if (sidstr == NULL) return NULL;
 435
 436         /* seen if its a well known sid */
 437         for (i=0;sid_codes[i].sid;i++) {
 438                 if (strcmp(sidstr, sid_codes[i].sid) == 0) {
 439                         talloc_free(sidstr);
 440                         return talloc_strdup(mem_ctx, sid_codes[i].code);
 441                 }
 442         }
 443
 444         /* or a well known rid in our domain */
 445         if (dom_sid_in_domain(domain_sid, sid)) {
 446                 uint32_t rid = sid->sub_auths[sid->num_auths-1];
 447                 for (;i<ARRAY_SIZE(sid_codes);i++) {
 448                         if (rid == sid_codes[i].rid) {
 449                                 talloc_free(sidstr);
 450                                 return talloc_strdup(mem_ctx, sid_codes[i].code);
 451                         }
 452                 }
 453         }
 454
 455         talloc_free(sidstr);
 456
 457         /* TODO: encode well known sids as two letter codes */
 458         return dom_sid_string(mem_ctx, sid);
 459 }
 460
 461
 462 /*
 463   encode an ACE in SDDL format
 464 */
 465 static char *sddl_encode_ace(TALLOC_CTX *mem_ctx, const struct security_ace *ace,
 466                              const struct dom_sid *domain_sid)
 467 {
 468         char *sddl = NULL;
 469         TALLOC_CTX *tmp_ctx;
 470         const char *s_type="", *s_flags="", *s_mask="",
 471                 *s_object="", *s_iobject="", *s_trustee="";
 472
 473         tmp_ctx = talloc_new(mem_ctx);
 474         if (tmp_ctx == NULL) {
 475                 DEBUG(0, ("talloc_new failed\n"));
 476                 return NULL;
 477         }
 478
 479         s_type = sddl_flags_to_string(tmp_ctx, ace_types, ace->type, true);
 480         if (s_type == NULL) goto failed;
 481
 482         s_flags = sddl_flags_to_string(tmp_ctx, ace_flags, ace->flags, true);
 483         if (s_flags == NULL) goto failed;
 484
 485         s_mask = sddl_flags_to_string(tmp_ctx, ace_access_mask, ace->access_mask, true);
 486         if (s_mask == NULL) {
 487                 s_mask = talloc_asprintf(tmp_ctx, "0x%08x", ace->access_mask);
 488                 if (s_mask == NULL) goto failed;
 489         }
 490
 491         if (ace->type == SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT ||
 492             ace->type == SEC_ACE_TYPE_ACCESS_DENIED_OBJECT ||
 493             ace->type == SEC_ACE_TYPE_SYSTEM_AUDIT_OBJECT ||
 494             ace->type == SEC_ACE_TYPE_SYSTEM_AUDIT_OBJECT) {
 495                 if (ace->object.object.flags & SEC_ACE_OBJECT_TYPE_PRESENT) {
 496                         s_object = GUID_string(tmp_ctx, &ace->object.object.type.type);
 497                         if (s_object == NULL) goto failed;
 498                 }
 499
 500                 if (ace->object.object.flags & SEC_ACE_INHERITED_OBJECT_TYPE_PRESENT) {
 501                         s_iobject = GUID_string(tmp_ctx, &ace->object.object.inherited_type.inherited_type);
 502                         if (s_iobject == NULL) goto failed;
 503                 }
 504         }
 505
 506         s_trustee = sddl_encode_sid(tmp_ctx, &ace->trustee, domain_sid);
 507         if (s_trustee == NULL) goto failed;
 508
 509         sddl = talloc_asprintf(mem_ctx, "%s;%s;%s;%s;%s;%s",
 510                                s_type, s_flags, s_mask, s_object, s_iobject, s_trustee);
 511
 512 failed:
 513         talloc_free(tmp_ctx);
 514         return sddl;
 515 }
 516
 517 /*
 518   encode an ACL in SDDL format
 519 */
 520 static char *sddl_encode_acl(TALLOC_CTX *mem_ctx, const struct security_acl *acl,
 521                              uint32_t flags, const struct dom_sid *domain_sid)
 522 {
 523         char *sddl;
 524         int i;
 525
 526         /* add any ACL flags */
 527         sddl = sddl_flags_to_string(mem_ctx, acl_flags, flags, false);
 528         if (sddl == NULL) goto failed;
 529
 530         /* now the ACEs, encoded in braces */
 531         for (i=0;i<acl->num_aces;i++) {
 532                 char *ace = sddl_encode_ace(sddl, &acl->aces[i], domain_sid);
 533                 if (ace == NULL) goto failed;
 534                 sddl = talloc_asprintf_append_buffer(sddl, "(%s)", ace);
 535                 if (sddl == NULL) goto failed;
 536                 talloc_free(ace);
 537         }
 538
 539         return sddl;
 540
 541 failed:
 542         talloc_free(sddl);
 543         return NULL;
 544 }
 545
 546
 547 /*
 548   encode a security descriptor to SDDL format
 549 */
 550 char *sddl_encode(TALLOC_CTX *mem_ctx, const struct security_descriptor *sd,
 551                   const struct dom_sid *domain_sid)
 552 {
 553         char *sddl;
 554         TALLOC_CTX *tmp_ctx;
 555
 556         /* start with a blank string */
 557         sddl = talloc_strdup(mem_ctx, "");
 558         if (sddl == NULL) goto failed;
 559
 560         tmp_ctx = talloc_new(mem_ctx);
 561
 562         if (sd->owner_sid != NULL) {
 563                 char *sid = sddl_encode_sid(tmp_ctx, sd->owner_sid, domain_sid);
 564                 if (sid == NULL) goto failed;
 565                 sddl = talloc_asprintf_append_buffer(sddl, "O:%s", sid);
 566                 if (sddl == NULL) goto failed;
 567         }
 568
 569         if (sd->group_sid != NULL) {
 570                 char *sid = sddl_encode_sid(tmp_ctx, sd->group_sid, domain_sid);
 571                 if (sid == NULL) goto failed;
 572                 sddl = talloc_asprintf_append_buffer(sddl, "G:%s", sid);
 573                 if (sddl == NULL) goto failed;
 574         }
 575
 576         if ((sd->type & SEC_DESC_DACL_PRESENT) && sd->dacl != NULL) {
 577                 char *acl = sddl_encode_acl(tmp_ctx, sd->dacl, sd->type, domain_sid);
 578                 if (acl == NULL) goto failed;
 579                 sddl = talloc_asprintf_append_buffer(sddl, "D:%s", acl);
 580                 if (sddl == NULL) goto failed;
 581         }
 582
 583         if ((sd->type & SEC_DESC_SACL_PRESENT) && sd->sacl != NULL) {
 584                 char *acl = sddl_encode_acl(tmp_ctx, sd->sacl, sd->type>>1, domain_sid);
 585                 if (acl == NULL) goto failed;
 586                 sddl = talloc_asprintf_append_buffer(sddl, "S:%s", acl);
 587                 if (sddl == NULL) goto failed;
 588         }
 589
 590         talloc_free(tmp_ctx);
 591         return sddl;
 592
 593 failed:
 594         talloc_free(sddl);
 595         return NULL;
 596 }
 597
 598