/* * Unix SMB/Netbios implementation. * SEC_DESC handling functions * Copyright (C) Jeremy R. Allison 1995-2003. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. */ #include "includes.h" /******************************************************************* Create the share security tdb. ********************************************************************/ static TDB_CONTEXT *share_tdb; /* used for share security descriptors */ #define SHARE_DATABASE_VERSION_V1 1 #define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */ /* Map generic permissions to file object specific permissions */ static struct generic_mapping file_generic_mapping = { FILE_GENERIC_READ, FILE_GENERIC_WRITE, FILE_GENERIC_EXECUTE, FILE_GENERIC_ALL }; BOOL share_info_db_init(void) { const char *vstring = "INFO/version"; int32 vers_id; if (share_tdb) { return True; } share_tdb = tdb_open_log(lock_path("share_info.tdb"), 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600); if (!share_tdb) { DEBUG(0,("Failed to open share info database %s (%s)\n", lock_path("share_info.tdb"), strerror(errno) )); return False; } /* handle a Samba upgrade */ tdb_lock_bystring(share_tdb, vstring); /* Cope with byte-reversed older versions of the db. */ vers_id = tdb_fetch_int32(share_tdb, vstring); if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) { /* Written on a bigendian machine with old fetch_int code. Save as le. */ tdb_store_int32(share_tdb, vstring, SHARE_DATABASE_VERSION_V2); vers_id = SHARE_DATABASE_VERSION_V2; } if (vers_id != SHARE_DATABASE_VERSION_V2) { tdb_traverse(share_tdb, tdb_traverse_delete_fn, NULL); tdb_store_int32(share_tdb, vstring, SHARE_DATABASE_VERSION_V2); } tdb_unlock_bystring(share_tdb, vstring); return True; } /******************************************************************* Fake up a Everyone, default access as a default. def_access is a GENERIC_XXX access mode. ********************************************************************/ SEC_DESC *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access) { SEC_ACCESS sa; SEC_ACE ace; SEC_ACL *psa = NULL; SEC_DESC *psd = NULL; uint32 spec_access = def_access; se_map_generic(&spec_access, &file_generic_mapping); init_sec_access(&sa, def_access | spec_access ); init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0); if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) { psd = make_sec_desc(ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, psa, psize); } if (!psd) { DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n")); return NULL; } return psd; } /******************************************************************* Pull a security descriptor from the share tdb. ********************************************************************/ SEC_DESC *get_share_security( TALLOC_CTX *ctx, const char *servicename, size_t *psize) { prs_struct ps; fstring key; SEC_DESC *psd = NULL; if (!share_info_db_init()) { return NULL; } *psize = 0; /* Fetch security descriptor from tdb */ slprintf(key, sizeof(key)-1, "SECDESC/%s", servicename); if (tdb_prs_fetch_bystring(share_tdb, key, &ps, ctx)!=0 || !sec_io_desc("get_share_security", &psd, &ps, 1)) { DEBUG(4, ("get_share_security: using default secdesc for %s\n", servicename)); return get_share_security_default(ctx, psize, GENERIC_ALL_ACCESS); } if (psd) *psize = sec_desc_size(psd); prs_mem_free(&ps); return psd; } /******************************************************************* Store a security descriptor in the share db. ********************************************************************/ BOOL set_share_security(const char *share_name, SEC_DESC *psd) { prs_struct ps; TALLOC_CTX *mem_ctx = NULL; fstring key; BOOL ret = False; if (!share_info_db_init()) { return False; } mem_ctx = talloc_init("set_share_security"); if (mem_ctx == NULL) return False; prs_init(&ps, (uint32)sec_desc_size(psd), mem_ctx, MARSHALL); if (!sec_io_desc("share_security", &psd, &ps, 1)) goto out; slprintf(key, sizeof(key)-1, "SECDESC/%s", share_name); if (tdb_prs_store_bystring(share_tdb, key, &ps)==0) { ret = True; DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name )); } else { DEBUG(1,("set_share_security: Failed to store secdesc for %s\n", share_name )); } /* Free malloc'ed memory */ out: prs_mem_free(&ps); TALLOC_FREE(mem_ctx); return ret; } /******************************************************************* Delete a security descriptor. ********************************************************************/ BOOL delete_share_security(const struct share_params *params) { TDB_DATA kbuf; fstring key; slprintf(key, sizeof(key)-1, "SECDESC/%s", lp_servicename(params->service)); kbuf = string_term_tdb_data(key); if (tdb_trans_delete(share_tdb, kbuf) != 0) { DEBUG(0,("delete_share_security: Failed to delete entry for share %s\n", lp_servicename(params->service) )); return False; } return True; } /******************************************************************* Can this user access with share with the required permissions ? ********************************************************************/ BOOL share_access_check(const NT_USER_TOKEN *token, const char *sharename, uint32 desired_access) { uint32 granted; NTSTATUS status; TALLOC_CTX *mem_ctx = NULL; SEC_DESC *psd = NULL; size_t sd_size; BOOL ret = True; if (!(mem_ctx = talloc_init("share_access_check"))) { return False; } psd = get_share_security(mem_ctx, sharename, &sd_size); if (!psd) { TALLOC_FREE(mem_ctx); return True; } ret = se_access_check(psd, token, desired_access, &granted, &status); talloc_destroy(mem_ctx); return ret; } /*************************************************************************** Parse the contents of an acl string from a usershare file. ***************************************************************************/ BOOL parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, SEC_DESC **ppsd) { size_t s_size = 0; const char *pacl = acl_str; int num_aces = 0; SEC_ACE *ace_list = NULL; SEC_ACL *psa = NULL; SEC_DESC *psd = NULL; size_t sd_size = 0; int i; *ppsd = NULL; /* If the acl string is blank return "Everyone:R" */ if (!*acl_str) { SEC_DESC *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS); if (!default_psd) { return False; } *ppsd = default_psd; return True; } num_aces = 1; /* Add the number of ',' characters to get the number of aces. */ num_aces += count_chars(pacl,','); ace_list = TALLOC_ARRAY(ctx, SEC_ACE, num_aces); if (!ace_list) { return False; } for (i = 0; i < num_aces; i++) { SEC_ACCESS sa; uint32 g_access; uint32 s_access; DOM_SID sid; fstring sidstr; uint8 type = SEC_ACE_TYPE_ACCESS_ALLOWED; if (!next_token(&pacl, sidstr, ":", sizeof(sidstr))) { DEBUG(0,("parse_usershare_acl: malformed usershare acl looking " "for ':' in string '%s'\n", pacl)); return False; } if (!string_to_sid(&sid, sidstr)) { DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n", sidstr )); return False; } switch (*pacl) { case 'F': /* Full Control, ie. R+W */ case 'f': /* Full Control, ie. R+W */ s_access = g_access = GENERIC_ALL_ACCESS; break; case 'R': /* Read only. */ case 'r': /* Read only. */ s_access = g_access = GENERIC_READ_ACCESS; break; case 'D': /* Deny all to this SID. */ case 'd': /* Deny all to this SID. */ type = SEC_ACE_TYPE_ACCESS_DENIED; s_access = g_access = GENERIC_ALL_ACCESS; break; default: DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n", pacl )); return False; } pacl++; if (*pacl && *pacl != ',') { DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n", pacl )); return False; } pacl++; /* Go past any ',' */ se_map_generic(&s_access, &file_generic_mapping); init_sec_access(&sa, g_access | s_access ); init_sec_ace(&ace_list[i], &sid, type, sa, 0); } if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) { psd = make_sec_desc(ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, psa, &sd_size); } if (!psd) { DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n")); return False; } *ppsd = psd; return True; }