/* * 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 struct db_context *share_db; /* used for share security descriptors */ #define SHARE_DATABASE_VERSION_V1 1 #define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */ #define SHARE_DATABASE_VERSION_V3 3 /* canonicalized sharenames as lower case */ #define SHARE_SECURITY_DB_KEY_PREFIX_STR "SECDESC/" /* Map generic permissions to file object specific permissions */ extern const struct generic_mapping file_generic_mapping; static int delete_fn(struct db_record *rec, void *priv) { rec->delete_rec(rec); return 0; } /***************************************************** Looking for keys of the form: SHARE_SECURITY_DB_KEY_PREFIX_STR + "non lower case str". If we find one re-write it into a canonical case form. *****************************************************/ static int upgrade_v2_to_v3(struct db_record *rec, void *priv) { size_t prefix_len = strlen(SHARE_SECURITY_DB_KEY_PREFIX_STR); const char *servicename = NULL; char *c_servicename = NULL; char *newkey = NULL; bool *p_upgrade_ok = (bool *)priv; NTSTATUS status; /* Is there space for a one character sharename ? */ if (rec->key.dsize <= prefix_len+2) { return 0; } /* Does it start with the share key prefix ? */ if (memcmp(rec->key.dptr, SHARE_SECURITY_DB_KEY_PREFIX_STR, prefix_len) != 0) { return 0; } /* Is it a null terminated string as a key ? */ if (rec->key.dptr[rec->key.dsize-1] != '\0') { return 0; } /* Bytes after the prefix are the sharename string. */ servicename = (char *)&rec->key.dptr[prefix_len]; c_servicename = canonicalize_servicename(talloc_tos(), servicename); if (!c_servicename) { smb_panic("out of memory upgrading share security db from v2 -> v3"); } if (strcmp(servicename, c_servicename) == 0) { /* Old and new names match. No canonicalization needed. */ TALLOC_FREE(c_servicename); return 0; } /* Oops. Need to canonicalize name, delete old then store new. */ status = rec->delete_rec(rec); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("upgrade_v2_to_v3: Failed to delete secdesc for " "%s: %s\n", rec->key.dptr, nt_errstr(status))); TALLOC_FREE(c_servicename); *p_upgrade_ok = false; return -1; } else { DEBUG(10, ("upgrade_v2_to_v3: deleted secdesc for " "%s\n", rec->key.dptr )); } if (!(newkey = talloc_asprintf(talloc_tos(), SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", c_servicename))) { smb_panic("out of memory upgrading share security db from v2 -> v3"); } status = dbwrap_store(share_db, string_term_tdb_data(newkey), rec->value, TDB_REPLACE); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("upgrade_v2_to_v3: Failed to store secdesc for " "%s: %s\n", c_servicename, nt_errstr(status))); TALLOC_FREE(c_servicename); TALLOC_FREE(newkey); *p_upgrade_ok = false; return -1; } else { DEBUG(10, ("upgrade_v2_to_v3: stored secdesc for " "%s\n", newkey )); } TALLOC_FREE(newkey); TALLOC_FREE(c_servicename); return 0; } bool share_info_db_init(void) { const char *vstring = "INFO/version"; int32 vers_id; int ret; bool upgrade_ok = true; if (share_db != NULL) { return True; } share_db = db_open(NULL, state_path("share_info.tdb"), 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600); if (share_db == NULL) { DEBUG(0,("Failed to open share info database %s (%s)\n", state_path("share_info.tdb"), strerror(errno) )); return False; } vers_id = dbwrap_fetch_int32(share_db, vstring); if (vers_id == SHARE_DATABASE_VERSION_V3) { return true; } if (share_db->transaction_start(share_db) != 0) { DEBUG(0, ("transaction_start failed\n")); TALLOC_FREE(share_db); return false; } vers_id = dbwrap_fetch_int32(share_db, vstring); if (vers_id == SHARE_DATABASE_VERSION_V3) { /* * Race condition */ if (share_db->transaction_cancel(share_db)) { smb_panic("transaction_cancel failed"); } return true; } /* Move to at least V2. */ /* Cope with byte-reversed older versions of the db. */ 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. */ if (dbwrap_store_int32(share_db, vstring, SHARE_DATABASE_VERSION_V2) != 0) { DEBUG(0, ("dbwrap_store_int32 failed\n")); goto cancel; } vers_id = SHARE_DATABASE_VERSION_V2; } if (vers_id != SHARE_DATABASE_VERSION_V2) { ret = share_db->traverse(share_db, delete_fn, NULL); if (ret < 0) { DEBUG(0, ("traverse failed\n")); goto cancel; } if (dbwrap_store_int32(share_db, vstring, SHARE_DATABASE_VERSION_V2) != 0) { DEBUG(0, ("dbwrap_store_int32 failed\n")); goto cancel; } } /* Finally upgrade to version 3, with canonicalized sharenames. */ ret = share_db->traverse(share_db, upgrade_v2_to_v3, &upgrade_ok); if (ret < 0 || upgrade_ok == false) { DEBUG(0, ("traverse failed\n")); goto cancel; } if (dbwrap_store_int32(share_db, vstring, SHARE_DATABASE_VERSION_V3) != 0) { DEBUG(0, ("dbwrap_store_int32 failed\n")); goto cancel; } if (share_db->transaction_commit(share_db) != 0) { DEBUG(0, ("transaction_commit failed\n")); return false; } return true; cancel: if (share_db->transaction_cancel(share_db)) { smb_panic("transaction_cancel failed"); } return false; } /******************************************************************* Fake up a Everyone, default access as a default. def_access is a GENERIC_XXX access mode. ********************************************************************/ struct security_descriptor *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access) { uint32_t sa; struct security_ace ace; struct security_acl *psa = NULL; struct security_descriptor *psd = NULL; uint32 spec_access = def_access; se_map_generic(&spec_access, &file_generic_mapping); 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, SECURITY_DESCRIPTOR_REVISION_1, 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. ********************************************************************/ struct security_descriptor *get_share_security( TALLOC_CTX *ctx, const char *servicename, size_t *psize) { char *key; struct security_descriptor *psd = NULL; TDB_DATA data; char *c_servicename = canonicalize_servicename(talloc_tos(), servicename); NTSTATUS status; if (!c_servicename) { return NULL; } if (!share_info_db_init()) { TALLOC_FREE(c_servicename); return NULL; } if (!(key = talloc_asprintf(ctx, SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", c_servicename))) { TALLOC_FREE(c_servicename); DEBUG(0, ("talloc_asprintf failed\n")); return NULL; } TALLOC_FREE(c_servicename); data = dbwrap_fetch_bystring(share_db, talloc_tos(), key); TALLOC_FREE(key); if (data.dptr == NULL) { return get_share_security_default(ctx, psize, GENERIC_ALL_ACCESS); } status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd); TALLOC_FREE(data.dptr); if (!NT_STATUS_IS_OK(status)) { DEBUG(0, ("unmarshall_sec_desc failed: %s\n", nt_errstr(status))); return get_share_security_default(ctx, psize, GENERIC_ALL_ACCESS); } if (psd) { *psize = ndr_size_security_descriptor(psd, 0); } else { return get_share_security_default(ctx, psize, GENERIC_ALL_ACCESS); } return psd; } /******************************************************************* Store a security descriptor in the share db. ********************************************************************/ bool set_share_security(const char *share_name, struct security_descriptor *psd) { TALLOC_CTX *frame = talloc_stackframe(); char *key; bool ret = False; TDB_DATA blob; NTSTATUS status; char *c_share_name = canonicalize_servicename(frame, share_name); if (!c_share_name) { goto out; } if (!share_info_db_init()) { goto out; } status = marshall_sec_desc(frame, psd, &blob.dptr, &blob.dsize); if (!NT_STATUS_IS_OK(status)) { DEBUG(0, ("marshall_sec_desc failed: %s\n", nt_errstr(status))); goto out; } if (!(key = talloc_asprintf(frame, SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", c_share_name))) { DEBUG(0, ("talloc_asprintf failed\n")); goto out; } status = dbwrap_trans_store(share_db, string_term_tdb_data(key), blob, TDB_REPLACE); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("set_share_security: Failed to store secdesc for " "%s: %s\n", share_name, nt_errstr(status))); goto out; } DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name )); ret = True; out: TALLOC_FREE(frame); return ret; } /******************************************************************* Delete a security descriptor. ********************************************************************/ bool delete_share_security(const char *servicename) { TDB_DATA kbuf; char *key; NTSTATUS status; char *c_servicename = canonicalize_servicename(talloc_tos(), servicename); if (!c_servicename) { return NULL; } if (!share_info_db_init()) { TALLOC_FREE(c_servicename); return False; } if (!(key = talloc_asprintf(talloc_tos(), SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", c_servicename))) { TALLOC_FREE(c_servicename); return False; } kbuf = string_term_tdb_data(key); status = dbwrap_trans_delete(share_db, kbuf); if (!NT_STATUS_IS_OK(status)) { DEBUG(0, ("delete_share_security: Failed to delete entry for " "share %s: %s\n", c_servicename, nt_errstr(status))); TALLOC_FREE(c_servicename); return False; } TALLOC_FREE(c_servicename); 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; struct security_descriptor *psd = NULL; size_t sd_size; psd = get_share_security(talloc_tos(), sharename, &sd_size); if (!psd) { return True; } status = se_access_check(psd, token, desired_access, &granted); TALLOC_FREE(psd); return NT_STATUS_IS_OK(status); } /*************************************************************************** Parse the contents of an acl string from a usershare file. ***************************************************************************/ bool parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, struct security_descriptor **ppsd) { size_t s_size = 0; const char *pacl = acl_str; int num_aces = 0; struct security_ace *ace_list = NULL; struct security_acl *psa = NULL; struct security_descriptor *psd = NULL; size_t sd_size = 0; int i; *ppsd = NULL; /* If the acl string is blank return "Everyone:R" */ if (!*acl_str) { struct security_descriptor *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, struct security_ace, num_aces); if (!ace_list) { return False; } for (i = 0; i < num_aces; i++) { uint32_t sa; uint32 g_access; uint32 s_access; struct dom_sid sid; char *sidstr; enum security_ace_type type = SEC_ACE_TYPE_ACCESS_ALLOWED; if (!next_token_talloc(ctx, &pacl, &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); 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, SECURITY_DESCRIPTOR_REVISION_1, 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; }