diff options
Diffstat (limited to 'source3/lib/sharesec.c')
| -rw-r--r-- | source3/lib/sharesec.c | 588 |
1 files changed, 588 insertions, 0 deletions
diff --git a/source3/lib/sharesec.c b/source3/lib/sharesec.c new file mode 100644 index 0000000..fbb2d47 --- /dev/null +++ b/source3/lib/sharesec.c @@ -0,0 +1,588 @@ +/* + * 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" +#include "system/filesys.h" +#include "../libcli/security/security.h" +#include "../librpc/gen_ndr/ndr_security.h" +#include "dbwrap/dbwrap.h" +#include "dbwrap/dbwrap_open.h" +#include "util_tdb.h" +#include "libcli/util/ntstatus.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) +{ + dbwrap_record_delete(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; + TDB_DATA key; + TDB_DATA value; + + key = dbwrap_record_get_key(rec); + + /* Is there space for a one character sharename ? */ + if (key.dsize <= prefix_len+2) { + return 0; + } + + /* Does it start with the share key prefix ? */ + if (memcmp(key.dptr, SHARE_SECURITY_DB_KEY_PREFIX_STR, + prefix_len) != 0) { + return 0; + } + + /* Is it a null terminated string as a key ? */ + if (key.dptr[key.dsize-1] != '\0') { + return 0; + } + + /* Bytes after the prefix are the sharename string. */ + servicename = (char *)&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 = dbwrap_record_delete(rec); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(1, ("upgrade_v2_to_v3: Failed to delete secdesc for " + "%s: %s\n", (const char *)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", (const char *)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"); + } + + value = dbwrap_record_get_value(rec); + status = dbwrap_store(share_db, + string_term_tdb_data(newkey), + 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; +} + +NTSTATUS share_info_db_init(void) +{ + const char *vstring = "INFO/version"; + int32_t vers_id = 0; + bool upgrade_ok = true; + NTSTATUS status; + char *db_path; + + if (share_db != NULL) { + return NT_STATUS_OK; + } + + db_path = state_path(talloc_tos(), "share_info.tdb"); + if (db_path == NULL) { + return NT_STATUS_NO_MEMORY; + } + + share_db = db_open(NULL, db_path, 0, + TDB_DEFAULT, O_RDWR|O_CREAT, 0600, + DBWRAP_LOCK_ORDER_1, DBWRAP_FLAG_NONE); + if (share_db == NULL) { + DEBUG(0,("Failed to open share info database %s (%s)\n", + db_path, strerror(errno))); + TALLOC_FREE(db_path); + return map_nt_error_from_unix_common(errno); + } + TALLOC_FREE(db_path); + + status = dbwrap_fetch_int32_bystring(share_db, vstring, &vers_id); + if (!NT_STATUS_IS_OK(status)) { + vers_id = 0; + } + + if (vers_id == SHARE_DATABASE_VERSION_V3) { + return NT_STATUS_OK; + } + + if (dbwrap_transaction_start(share_db) != 0) { + DEBUG(0, ("transaction_start failed\n")); + TALLOC_FREE(share_db); + return NT_STATUS_INTERNAL_DB_ERROR; + } + + status = dbwrap_fetch_int32_bystring(share_db, vstring, &vers_id); + if (!NT_STATUS_IS_OK(status)) { + vers_id = 0; + } + + if (vers_id == SHARE_DATABASE_VERSION_V3) { + /* + * Race condition + */ + if (dbwrap_transaction_cancel(share_db)) { + smb_panic("transaction_cancel failed"); + } + return NT_STATUS_OK; + } + + /* 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. */ + + status = dbwrap_store_int32_bystring( + share_db, vstring, SHARE_DATABASE_VERSION_V2); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0, ("dbwrap_store_int32 failed: %s\n", + nt_errstr(status))); + goto cancel; + } + vers_id = SHARE_DATABASE_VERSION_V2; + } + + if (vers_id != SHARE_DATABASE_VERSION_V2) { + status = dbwrap_traverse(share_db, delete_fn, NULL, NULL); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0, ("traverse failed\n")); + goto cancel; + } + status = dbwrap_store_int32_bystring( + share_db, vstring, SHARE_DATABASE_VERSION_V2); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0, ("dbwrap_store_int32 failed: %s\n", + nt_errstr(status))); + goto cancel; + } + } + + /* Finally upgrade to version 3, with canonicalized sharenames. */ + + status = dbwrap_traverse(share_db, upgrade_v2_to_v3, &upgrade_ok, NULL); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0, ("traverse failed\n")); + goto cancel; + } + if (!upgrade_ok) { + DBG_ERR("upgrade failed.\n"); + status = NT_STATUS_INTERNAL_ERROR; + goto cancel; + } + + status = dbwrap_store_int32_bystring( + share_db, vstring, SHARE_DATABASE_VERSION_V3); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0, ("dbwrap_store_int32 failed: %s\n", + nt_errstr(status))); + goto cancel; + } + + if (dbwrap_transaction_commit(share_db) != 0) { + DEBUG(0, ("transaction_commit failed\n")); + return NT_STATUS_INTERNAL_ERROR; + } + + return NT_STATUS_OK; + + cancel: + if (dbwrap_transaction_cancel(share_db)) { + smb_panic("transaction_cancel failed"); + } + + return status; +} + +/******************************************************************* + Fake up a Everyone, default access as a default. + def_access is a GENERIC_XXX access mode. + ********************************************************************/ + +static struct security_descriptor *get_share_security_default(TALLOC_CTX *ctx, + size_t *psize, + uint32_t def_access) +{ + uint32_t sa; + struct security_ace ace; + struct security_acl *psa = NULL; + struct security_descriptor *psd = NULL; + uint32_t 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; + } + + status = share_info_db_init(); + if (!NT_STATUS_IS_OK(status)) { + 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); + + status = dbwrap_fetch_bystring(share_db, talloc_tos(), key, &data); + + TALLOC_FREE(key); + + if (!NT_STATUS_IS_OK(status)) { + return get_share_security_default(ctx, psize, + SEC_RIGHTS_DIR_ALL); + } + + status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd); + + TALLOC_FREE(data.dptr); + + if (!NT_STATUS_IS_OK(status)) { + return get_share_security_default(ctx, psize, + SEC_RIGHTS_DIR_ALL); + } + + if (psd) { + *psize = ndr_size_security_descriptor(psd, 0); + } else { + return get_share_security_default(ctx, psize, + SEC_RIGHTS_DIR_ALL); + } + + return psd; +} + +/******************************************************************* + Store a security descriptor in the share db. + ********************************************************************/ + +NTSTATUS set_share_security(const char *share_name, + struct security_descriptor *psd) +{ + TALLOC_CTX *frame = talloc_stackframe(); + char *key; + TDB_DATA blob; + NTSTATUS status; + char *c_share_name = canonicalize_servicename(frame, share_name); + + if (c_share_name == NULL) { + status = NT_STATUS_INVALID_PARAMETER; + goto out; + } + + status = share_info_db_init(); + if (!NT_STATUS_IS_OK(status)) { + 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")); + status = NT_STATUS_NO_MEMORY; + 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 )); + status = NT_STATUS_OK; + + out: + TALLOC_FREE(frame); + return status; +} + +/******************************************************************* + Delete a security descriptor. +********************************************************************/ + +NTSTATUS delete_share_security(const char *servicename) +{ + TDB_DATA kbuf; + char *key; + NTSTATUS status; + char *c_servicename = canonicalize_servicename(talloc_tos(), servicename); + + if (c_servicename == NULL) { + return NT_STATUS_INVALID_PARAMETER; + } + + status = share_info_db_init(); + if (!NT_STATUS_IS_OK(status)) { + TALLOC_FREE(c_servicename); + return status; + } + + if (!(key = talloc_asprintf(talloc_tos(), SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", + c_servicename))) { + TALLOC_FREE(c_servicename); + return NT_STATUS_NO_MEMORY; + } + 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 status; + } + + TALLOC_FREE(c_servicename); + return NT_STATUS_OK; +} + +/******************************************************************* + Can this user access with share with the required permissions ? +********************************************************************/ + +bool share_access_check(const struct security_token *token, + const char *sharename, + uint32_t desired_access, + uint32_t *pgranted) +{ + uint32_t granted; + NTSTATUS status; + struct security_descriptor *psd = NULL; + size_t sd_size; + + psd = get_share_security(talloc_tos(), sharename, &sd_size); + + if (!psd) { + if (pgranted != NULL) { + *pgranted = desired_access; + } + return false; + } + + status = se_file_access_check(psd, token, true, desired_access, &granted); + + TALLOC_FREE(psd); + + if (pgranted != NULL) { + *pgranted = granted; + } + + 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_t g_access; + uint32_t 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; +} |