1/* 2 * Unix SMB/Netbios implementation. 3 * SEC_DESC handling functions 4 * Copyright (C) Jeremy R. Allison 1995-2003. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21#include "includes.h" 22 23/******************************************************************* 24 Create the share security tdb. 25 ********************************************************************/ 26 27static TDB_CONTEXT *share_tdb; /* used for share security descriptors */ 28#define SHARE_DATABASE_VERSION_V1 1 29#define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */ 30 31/* Map generic permissions to file object specific permissions */ 32 33static struct generic_mapping file_generic_mapping = { 34 FILE_GENERIC_READ, 35 FILE_GENERIC_WRITE, 36 FILE_GENERIC_EXECUTE, 37 FILE_GENERIC_ALL 38}; 39 40 41BOOL share_info_db_init(void) 42{ 43 const char *vstring = "INFO/version"; 44 int32 vers_id; 45 46 if (share_tdb) { 47 return True; 48 } 49 50 share_tdb = tdb_open_log(lock_path("share_info.tdb"), 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600); 51 if (!share_tdb) { 52 DEBUG(0,("Failed to open share info database %s (%s)\n", 53 lock_path("share_info.tdb"), strerror(errno) )); 54 return False; 55 } 56 57 /* handle a Samba upgrade */ 58 tdb_lock_bystring(share_tdb, vstring); 59 60 /* Cope with byte-reversed older versions of the db. */ 61 vers_id = tdb_fetch_int32(share_tdb, vstring); 62 if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) { 63 /* Written on a bigendian machine with old fetch_int code. Save as le. */ 64 tdb_store_int32(share_tdb, vstring, SHARE_DATABASE_VERSION_V2); 65 vers_id = SHARE_DATABASE_VERSION_V2; 66 } 67 68 if (vers_id != SHARE_DATABASE_VERSION_V2) { 69 tdb_traverse(share_tdb, tdb_traverse_delete_fn, NULL); 70 tdb_store_int32(share_tdb, vstring, SHARE_DATABASE_VERSION_V2); 71 } 72 tdb_unlock_bystring(share_tdb, vstring); 73 74 return True; 75} 76 77/******************************************************************* 78 Fake up a Everyone, default access as a default. 79 def_access is a GENERIC_XXX access mode. 80 ********************************************************************/ 81 82SEC_DESC *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access) 83{ 84 SEC_ACCESS sa; 85 SEC_ACE ace; 86 SEC_ACL *psa = NULL; 87 SEC_DESC *psd = NULL; 88 uint32 spec_access = def_access; 89 90 se_map_generic(&spec_access, &file_generic_mapping); 91 92 init_sec_access(&sa, def_access | spec_access ); 93 init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0); 94 95 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) { 96 psd = make_sec_desc(ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, psa, psize); 97 } 98 99 if (!psd) { 100 DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n")); 101 return NULL; 102 } 103 104 return psd; 105} 106 107/******************************************************************* 108 Pull a security descriptor from the share tdb. 109 ********************************************************************/ 110 111SEC_DESC *get_share_security( TALLOC_CTX *ctx, const char *servicename, 112 size_t *psize) 113{ 114 prs_struct ps; 115 fstring key; 116 SEC_DESC *psd = NULL; 117 118 if (!share_info_db_init()) { 119 return NULL; 120 } 121 122 *psize = 0; 123 124 /* Fetch security descriptor from tdb */ 125 126 slprintf(key, sizeof(key)-1, "SECDESC/%s", servicename); 127 128 if (tdb_prs_fetch(share_tdb, key, &ps, ctx)!=0 || 129 !sec_io_desc("get_share_security", &psd, &ps, 1)) { 130 131 DEBUG(4, ("get_share_security: using default secdesc for %s\n", 132 servicename)); 133 134 return get_share_security_default(ctx, psize, GENERIC_ALL_ACCESS); 135 } 136 137 if (psd) 138 *psize = sec_desc_size(psd); 139 140 prs_mem_free(&ps); 141 return psd; 142} 143 144/******************************************************************* 145 Store a security descriptor in the share db. 146 ********************************************************************/ 147 148BOOL set_share_security(const char *share_name, SEC_DESC *psd) 149{ 150 prs_struct ps; 151 TALLOC_CTX *mem_ctx = NULL; 152 fstring key; 153 BOOL ret = False; 154 155 if (!share_info_db_init()) { 156 return False; 157 } 158 159 mem_ctx = talloc_init("set_share_security"); 160 if (mem_ctx == NULL) 161 return False; 162 163 prs_init(&ps, (uint32)sec_desc_size(psd), mem_ctx, MARSHALL); 164 165 if (!sec_io_desc("share_security", &psd, &ps, 1)) 166 goto out; 167 168 slprintf(key, sizeof(key)-1, "SECDESC/%s", share_name); 169 170 if (tdb_prs_store(share_tdb, key, &ps)==0) { 171 ret = True; 172 DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name )); 173 } else { 174 DEBUG(1,("set_share_security: Failed to store secdesc for %s\n", share_name )); 175 } 176 177 /* Free malloc'ed memory */ 178 179out: 180 181 prs_mem_free(&ps); 182 if (mem_ctx) 183 talloc_destroy(mem_ctx); 184 return ret; 185} 186 187/******************************************************************* 188 Delete a security descriptor. 189********************************************************************/ 190 191BOOL delete_share_security(const struct share_params *params) 192{ 193 TDB_DATA kbuf; 194 fstring key; 195 196 slprintf(key, sizeof(key)-1, "SECDESC/%s", 197 lp_servicename(params->service)); 198 kbuf.dptr = key; 199 kbuf.dsize = strlen(key)+1; 200 201 if (tdb_trans_delete(share_tdb, kbuf) != 0) { 202 DEBUG(0,("delete_share_security: Failed to delete entry for share %s\n", 203 lp_servicename(params->service) )); 204 return False; 205 } 206 207 return True; 208} 209 210/******************************************************************* 211 Can this user access with share with the required permissions ? 212********************************************************************/ 213 214BOOL share_access_check(const NT_USER_TOKEN *token, const char *sharename, 215 uint32 desired_access) 216{ 217 uint32 granted; 218 NTSTATUS status; 219 TALLOC_CTX *mem_ctx = NULL; 220 SEC_DESC *psd = NULL; 221 size_t sd_size; 222 BOOL ret = True; 223 224 if (!(mem_ctx = talloc_init("share_access_check"))) { 225 return False; 226 } 227 228 psd = get_share_security(mem_ctx, sharename, &sd_size); 229 230 if (!psd) { 231 TALLOC_FREE(mem_ctx); 232 return True; 233 } 234 235 ret = se_access_check(psd, token, desired_access, &granted, &status); 236 237 talloc_destroy(mem_ctx); 238 return ret; 239} 240 241/*************************************************************************** 242 Parse the contents of an acl string from a usershare file. 243***************************************************************************/ 244 245BOOL parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, SEC_DESC **ppsd) 246{ 247 size_t s_size = 0; 248 const char *pacl = acl_str; 249 int num_aces = 0; 250 SEC_ACE *ace_list = NULL; 251 SEC_ACL *psa = NULL; 252 SEC_DESC *psd = NULL; 253 size_t sd_size = 0; 254 int i; 255 256 *ppsd = NULL; 257 258 /* If the acl string is blank return "Everyone:R" */ 259 if (!*acl_str) { 260 SEC_DESC *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS); 261 if (!default_psd) { 262 return False; 263 } 264 *ppsd = default_psd; 265 return True; 266 } 267 268 num_aces = 1; 269 270 /* Add the number of ',' characters to get the number of aces. */ 271 num_aces += count_chars(pacl,','); 272 273 ace_list = TALLOC_ARRAY(ctx, SEC_ACE, num_aces); 274 if (!ace_list) { 275 return False; 276 } 277 278 for (i = 0; i < num_aces; i++) { 279 SEC_ACCESS sa; 280 uint32 g_access; 281 uint32 s_access; 282 DOM_SID sid; 283 fstring sidstr; 284 uint8 type = SEC_ACE_TYPE_ACCESS_ALLOWED; 285 286 if (!next_token(&pacl, sidstr, ":", sizeof(sidstr))) { 287 DEBUG(0,("parse_usershare_acl: malformed usershare acl looking " 288 "for ':' in string '%s'\n", pacl)); 289 return False; 290 } 291 292 if (!string_to_sid(&sid, sidstr)) { 293 DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n", 294 sidstr )); 295 return False; 296 } 297 298 switch (*pacl) { 299 case 'F': /* Full Control, ie. R+W */ 300 case 'f': /* Full Control, ie. R+W */ 301 s_access = g_access = GENERIC_ALL_ACCESS; 302 break; 303 case 'R': /* Read only. */ 304 case 'r': /* Read only. */ 305 s_access = g_access = GENERIC_READ_ACCESS; 306 break; 307 case 'D': /* Deny all to this SID. */ 308 case 'd': /* Deny all to this SID. */ 309 type = SEC_ACE_TYPE_ACCESS_DENIED; 310 s_access = g_access = GENERIC_ALL_ACCESS; 311 break; 312 default: 313 DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n", 314 pacl )); 315 return False; 316 } 317 318 pacl++; 319 if (*pacl && *pacl != ',') { 320 DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n", 321 pacl )); 322 return False; 323 } 324 pacl++; /* Go past any ',' */ 325 326 se_map_generic(&s_access, &file_generic_mapping); 327 init_sec_access(&sa, g_access | s_access ); 328 init_sec_ace(&ace_list[i], &sid, type, sa, 0); 329 } 330 331 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) { 332 psd = make_sec_desc(ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, psa, &sd_size); 333 } 334 335 if (!psd) { 336 DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n")); 337 return False; 338 } 339 340 *ppsd = psd; 341 return True; 342} 343