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samba-mirror/source3/modules/vfs_acl_common.c

673 lines
18 KiB
C

/*
* Store Windows ACLs in data store - common functions.
* #included into modules/vfs_acl_xattr.c and modules/vfs_acl_tdb.c
*
* Copyright (C) Volker Lendecke, 2008
* Copyright (C) Jeremy Allison, 2009
*
* 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/>.
*/
static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
DATA_BLOB *pblob,
uint16_t hash_type,
uint8_t hash[XATTR_SD_HASH_SIZE]);
static NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
vfs_handle_struct *handle,
files_struct *fsp,
const char *name,
DATA_BLOB *pblob);
static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
files_struct *fsp,
DATA_BLOB *pblob);
static NTSTATUS store_acl_blob_pathname(vfs_handle_struct *handle,
const char *fname,
DATA_BLOB *pblob);
#define HASH_SECURITY_INFO (OWNER_SECURITY_INFORMATION | \
GROUP_SECURITY_INFORMATION | \
DACL_SECURITY_INFORMATION | \
SACL_SECURITY_INFORMATION)
/*******************************************************************
Hash a security descriptor.
*******************************************************************/
static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
uint8_t *hash)
{
DATA_BLOB blob;
SHA256_CTX tctx;
NTSTATUS status;
memset(hash, '\0', XATTR_SD_HASH_SIZE);
status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
SHA256_Init(&tctx);
SHA256_Update(&tctx, blob.data, blob.length);
SHA256_Final(hash, &tctx);
return NT_STATUS_OK;
}
/*******************************************************************
Parse out a struct security_descriptor from a DATA_BLOB.
*******************************************************************/
static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
struct security_descriptor **ppdesc,
uint16_t *p_hash_type,
uint8_t hash[XATTR_SD_HASH_SIZE])
{
TALLOC_CTX *ctx = talloc_tos();
struct xattr_NTACL xacl;
enum ndr_err_code ndr_err;
size_t sd_size;
ndr_err = ndr_pull_struct_blob(pblob, ctx, NULL, &xacl,
(ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DEBUG(5, ("parse_acl_blob: ndr_pull_xattr_NTACL failed: %s\n",
ndr_errstr(ndr_err)));
return ndr_map_error2ntstatus(ndr_err);;
}
switch (xacl.version) {
case 2:
*ppdesc = make_sec_desc(ctx, SEC_DESC_REVISION,
xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
xacl.info.sd_hs2->sd->owner_sid,
xacl.info.sd_hs2->sd->group_sid,
xacl.info.sd_hs2->sd->sacl,
xacl.info.sd_hs2->sd->dacl,
&sd_size);
/* No hash - null out. */
*p_hash_type = XATTR_SD_HASH_TYPE_NONE;
memset(hash, '\0', XATTR_SD_HASH_SIZE);
break;
case 3:
*ppdesc = make_sec_desc(ctx, SEC_DESC_REVISION,
xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
xacl.info.sd_hs3->sd->owner_sid,
xacl.info.sd_hs3->sd->group_sid,
xacl.info.sd_hs3->sd->sacl,
xacl.info.sd_hs3->sd->dacl,
&sd_size);
*p_hash_type = xacl.info.sd_hs3->hash_type;
/* Current version 3. */
memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
break;
default:
return NT_STATUS_REVISION_MISMATCH;
}
TALLOC_FREE(xacl.info.sd);
return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
}
/*******************************************************************
Create a DATA_BLOB from a security descriptor.
*******************************************************************/
static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
DATA_BLOB *pblob,
uint16_t hash_type,
uint8_t hash[XATTR_SD_HASH_SIZE])
{
struct xattr_NTACL xacl;
struct security_descriptor_hash_v3 sd_hs3;
enum ndr_err_code ndr_err;
TALLOC_CTX *ctx = talloc_tos();
ZERO_STRUCT(xacl);
ZERO_STRUCT(sd_hs3);
xacl.version = 3;
xacl.info.sd_hs3 = &sd_hs3;
xacl.info.sd_hs3->sd = CONST_DISCARD(struct security_descriptor *, psd);
xacl.info.sd_hs3->hash_type = hash_type;
memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
ndr_err = ndr_push_struct_blob(
pblob, ctx, NULL, &xacl,
(ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DEBUG(5, ("create_acl_blob: ndr_push_xattr_NTACL failed: %s\n",
ndr_errstr(ndr_err)));
return ndr_map_error2ntstatus(ndr_err);;
}
return NT_STATUS_OK;
}
/*******************************************************************
Store a DATA_BLOB into an xattr given a pathname.
*******************************************************************/
static NTSTATUS get_nt_acl_internal(vfs_handle_struct *handle,
files_struct *fsp,
const char *name,
uint32_t security_info,
struct security_descriptor **ppdesc)
{
DATA_BLOB blob;
NTSTATUS status;
uint16_t hash_type;
uint8_t hash[XATTR_SD_HASH_SIZE];
uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
struct security_descriptor *pdesc_next = NULL;
if (fsp && name == NULL) {
name = fsp->fsp_name->base_name;
}
DEBUG(10, ("get_nt_acl_internal: name=%s\n", name));
status = get_acl_blob(talloc_tos(), handle, fsp, name, &blob);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(10, ("get_acl_blob returned %s\n", nt_errstr(status)));
return status;
}
status = parse_acl_blob(&blob, ppdesc,
&hash_type, &hash[0]);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(10, ("parse_acl_blob returned %s\n",
nt_errstr(status)));
return status;
}
/* Ensure the hash type is one we know. */
switch (hash_type) {
case XATTR_SD_HASH_TYPE_NONE:
/* No hash, goto return blob sd. */
goto out;
case XATTR_SD_HASH_TYPE_SHA256:
break;
default:
return NT_STATUS_REVISION_MISMATCH;
}
/* Get the full underlying sd, then hash. */
if (fsp) {
status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
fsp,
HASH_SECURITY_INFO,
&pdesc_next);
} else {
status = SMB_VFS_NEXT_GET_NT_ACL(handle,
name,
HASH_SECURITY_INFO,
&pdesc_next);
}
if (!NT_STATUS_IS_OK(status)) {
goto out;
}
status = hash_sd_sha256(pdesc_next, hash_tmp);
if (!NT_STATUS_IS_OK(status)) {
goto out;
}
if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
TALLOC_FREE(pdesc_next);
/* Hash matches, return blob sd. */
goto out;
}
/* Hash doesn't match, return underlying sd. */
if (!(security_info & OWNER_SECURITY_INFORMATION)) {
pdesc_next->owner_sid = NULL;
}
if (!(security_info & GROUP_SECURITY_INFORMATION)) {
pdesc_next->group_sid = NULL;
}
if (!(security_info & DACL_SECURITY_INFORMATION)) {
pdesc_next->dacl = NULL;
}
if (!(security_info & SACL_SECURITY_INFORMATION)) {
pdesc_next->sacl = NULL;
}
TALLOC_FREE(*ppdesc);
*ppdesc = pdesc_next;
out:
if (!(security_info & OWNER_SECURITY_INFORMATION)) {
(*ppdesc)->owner_sid = NULL;
}
if (!(security_info & GROUP_SECURITY_INFORMATION)) {
(*ppdesc)->group_sid = NULL;
}
if (!(security_info & DACL_SECURITY_INFORMATION)) {
(*ppdesc)->dacl = NULL;
}
if (!(security_info & SACL_SECURITY_INFORMATION)) {
(*ppdesc)->sacl = NULL;
}
TALLOC_FREE(blob.data);
return status;
}
/*********************************************************************
Create a default security descriptor for a file in case no inheritance
exists. All permissions to the owner and SYSTEM.
*********************************************************************/
static struct security_descriptor *default_file_sd(TALLOC_CTX *mem_ctx,
SMB_STRUCT_STAT *psbuf,
bool force_inherit)
{
struct dom_sid owner_sid, group_sid;
size_t sd_size;
struct security_ace *pace = NULL;
struct security_acl *pacl = NULL;
uid_to_sid(&owner_sid, psbuf->st_ex_uid);
gid_to_sid(&group_sid, psbuf->st_ex_gid);
pace = TALLOC_ARRAY(mem_ctx, struct security_ace, 2);
if (!pace) {
return NULL;
}
/* If force_inherit is set, this means we are initializing the ACEs for
* a container and we want the ACEs for owner_sid and "SYSTEM" to be
* inheritable by their children (See Bug #6802).
*/
init_sec_ace(&pace[0], &owner_sid, SEC_ACE_TYPE_ACCESS_ALLOWED,
SEC_RIGHTS_FILE_ALL, (force_inherit ?
(SEC_ACE_FLAG_OBJECT_INHERIT|
SEC_ACE_FLAG_CONTAINER_INHERIT) :
0));
init_sec_ace(&pace[1], &global_sid_System, SEC_ACE_TYPE_ACCESS_ALLOWED,
SEC_RIGHTS_FILE_ALL, (force_inherit ?
(SEC_ACE_FLAG_OBJECT_INHERIT|
SEC_ACE_FLAG_CONTAINER_INHERIT) :
0));
pacl = make_sec_acl(mem_ctx,
NT4_ACL_REVISION,
2,
pace);
if (!pacl) {
return NULL;
}
return make_sec_desc(mem_ctx,
SECURITY_DESCRIPTOR_REVISION_1,
SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT,
&owner_sid,
&group_sid,
NULL,
pacl,
&sd_size);
}
/*********************************************************************
*********************************************************************/
static NTSTATUS inherit_new_acl(vfs_handle_struct *handle,
struct smb_filename *smb_fname,
files_struct *fsp,
bool container)
{
TALLOC_CTX *ctx = talloc_tos();
NTSTATUS status;
struct security_descriptor *parent_desc = NULL;
struct security_descriptor *psd = NULL;
struct security_descriptor *pdesc_next = NULL;
DATA_BLOB blob;
size_t size;
char *parent_name;
bool force_inherit = false;
uint8_t hash[XATTR_SD_HASH_SIZE];
if (!parent_dirname(ctx, smb_fname->base_name, &parent_name, NULL)) {
return NT_STATUS_NO_MEMORY;
}
DEBUG(10,("inherit_new_acl: check directory %s\n",
parent_name));
status = get_nt_acl_internal(handle,
NULL,
parent_name,
(OWNER_SECURITY_INFORMATION |
GROUP_SECURITY_INFORMATION |
DACL_SECURITY_INFORMATION),
&parent_desc);
if (NT_STATUS_IS_OK(status)) {
/* Create an inherited descriptor from the parent. */
if (DEBUGLEVEL >= 10) {
DEBUG(10,("inherit_new_acl: parent acl is:\n"));
NDR_PRINT_DEBUG(security_descriptor, parent_desc);
}
status = se_create_child_secdesc(ctx,
&psd,
&size,
parent_desc,
&handle->conn->server_info->ptok->user_sids[PRIMARY_USER_SID_INDEX],
&handle->conn->server_info->ptok->user_sids[PRIMARY_GROUP_SID_INDEX],
container);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
if (DEBUGLEVEL >= 10) {
DEBUG(10,("inherit_new_acl: child acl is:\n"));
NDR_PRINT_DEBUG(security_descriptor, psd);
}
} else {
DEBUG(10,("inherit_new_acl: directory %s failed "
"to get acl %s\n",
parent_name,
nt_errstr(status) ));
}
if (!psd || psd->dacl == NULL) {
TALLOC_FREE(psd);
if (fsp) {
status = vfs_stat_fsp(fsp);
smb_fname->st = fsp->fsp_name->st;
} else {
int ret;
if (lp_posix_pathnames()) {
ret = SMB_VFS_LSTAT(handle->conn, smb_fname);
} else {
ret = SMB_VFS_STAT(handle->conn, smb_fname);
}
if (ret == -1) {
status = map_nt_error_from_unix(errno);
}
}
if (!NT_STATUS_IS_OK(status)) {
return status;
}
/* If we get here, we could have the following possibilities:
* 1. No ACLs exist on the parent container.
* 2. ACLs exist on the parent container but they were
* not inheritable.
*
* Check to see if case #1 occurred.
*
*/
if (container &&
(parent_desc == NULL || parent_desc->dacl == NULL)) {
/* If no parent descriptor exists, then there were
* no ACLs on the parent and then we must create
* the ACLs on this newly created folder so that they
* will be inherited by their children (See Bug #6802).
*/
force_inherit = true;
}
psd = default_file_sd(ctx, &smb_fname->st, force_inherit);
if (!psd) {
return NT_STATUS_NO_MEMORY;
}
if (DEBUGLEVEL >= 10) {
DEBUG(10,("inherit_new_acl: default acl is:\n"));
NDR_PRINT_DEBUG(security_descriptor, psd);
}
}
/* Object exists. Read the current SD to get the hash. */
if (fsp) {
status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
fsp,
HASH_SECURITY_INFO,
&pdesc_next);
} else {
status = SMB_VFS_NEXT_GET_NT_ACL(handle,
smb_fname->base_name,
HASH_SECURITY_INFO,
&pdesc_next);
}
if (!NT_STATUS_IS_OK(status)) {
return status;
}
status = hash_sd_sha256(pdesc_next, hash);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
if (fsp) {
return store_acl_blob_fsp(handle, fsp, &blob);
} else {
return store_acl_blob_pathname(handle, smb_fname->base_name,
&blob);
}
}
/*********************************************************************
Check ACL on open. For new files inherit from parent directory.
*********************************************************************/
static int open_acl_common(vfs_handle_struct *handle,
struct smb_filename *smb_fname,
files_struct *fsp,
int flags,
mode_t mode)
{
uint32_t access_granted = 0;
struct security_descriptor *pdesc = NULL;
bool file_existed = true;
char *fname = NULL;
NTSTATUS status;
if (fsp->base_fsp) {
/* Stream open. Base filename open already did the ACL check. */
DEBUG(10,("open_acl_common: stream open on %s\n",
smb_fname_str_dbg(smb_fname) ));
return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
}
status = get_full_smb_filename(talloc_tos(), smb_fname,
&fname);
if (!NT_STATUS_IS_OK(status)) {
errno = map_errno_from_nt_status(status);
return -1;
}
status = get_nt_acl_internal(handle,
NULL,
fname,
(OWNER_SECURITY_INFORMATION |
GROUP_SECURITY_INFORMATION |
DACL_SECURITY_INFORMATION),
&pdesc);
if (NT_STATUS_IS_OK(status)) {
/* See if we can access it. */
status = smb1_file_se_access_check(pdesc,
handle->conn->server_info->ptok,
fsp->access_mask,
&access_granted);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(10,("open_acl_xattr: file %s open "
"refused with error %s\n",
smb_fname_str_dbg(smb_fname),
nt_errstr(status) ));
errno = map_errno_from_nt_status(status);
return -1;
}
} else if (NT_STATUS_EQUAL(status,NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
file_existed = false;
}
DEBUG(10,("open_acl_xattr: get_nt_acl_attr_internal for "
"file %s returned %s\n",
smb_fname_str_dbg(smb_fname),
nt_errstr(status) ));
fsp->fh->fd = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
if (!file_existed && fsp->fh->fd != -1) {
/* File was created. Inherit from parent directory. */
status = fsp_set_smb_fname(fsp, smb_fname);
if (!NT_STATUS_IS_OK(status)) {
errno = map_errno_from_nt_status(status);
return -1;
}
inherit_new_acl(handle, smb_fname, fsp, false);
}
return fsp->fh->fd;
}
static int mkdir_acl_common(vfs_handle_struct *handle, const char *path, mode_t mode)
{
struct smb_filename *smb_fname = NULL;
int ret = SMB_VFS_NEXT_MKDIR(handle, path, mode);
NTSTATUS status;
if (ret == -1) {
return ret;
}
status = create_synthetic_smb_fname(talloc_tos(), path, NULL, NULL,
&smb_fname);
if (!NT_STATUS_IS_OK(status)) {
errno = map_errno_from_nt_status(status);
return -1;
}
/* New directory - inherit from parent. */
inherit_new_acl(handle, smb_fname, NULL, true);
TALLOC_FREE(smb_fname);
return ret;
}
/*********************************************************************
Fetch a security descriptor given an fsp.
*********************************************************************/
static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
uint32_t security_info, struct security_descriptor **ppdesc)
{
return get_nt_acl_internal(handle, fsp,
NULL, security_info, ppdesc);
}
/*********************************************************************
Fetch a security descriptor given a pathname.
*********************************************************************/
static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
const char *name, uint32_t security_info, struct security_descriptor **ppdesc)
{
return get_nt_acl_internal(handle, NULL,
name, security_info, ppdesc);
}
/*********************************************************************
Store a security descriptor given an fsp.
*********************************************************************/
static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
uint32_t security_info_sent, const struct security_descriptor *psd)
{
NTSTATUS status;
DATA_BLOB blob;
struct security_descriptor *pdesc_next = NULL;
uint8_t hash[XATTR_SD_HASH_SIZE];
if (DEBUGLEVEL >= 10) {
DEBUG(10,("fset_nt_acl_xattr: incoming sd for file %s\n",
fsp_str_dbg(fsp)));
NDR_PRINT_DEBUG(security_descriptor,
CONST_DISCARD(struct security_descriptor *,psd));
}
/* Ensure owner and group are set. */
if (!psd->owner_sid || !psd->group_sid) {
DOM_SID owner_sid, group_sid;
struct security_descriptor *nc_psd = dup_sec_desc(talloc_tos(), psd);
if (!nc_psd) {
return NT_STATUS_OK;
}
status = vfs_stat_fsp(fsp);
if (!NT_STATUS_IS_OK(status)) {
/* Lower level acl set succeeded,
* so still return OK. */
return NT_STATUS_OK;
}
create_file_sids(&fsp->fsp_name->st, &owner_sid, &group_sid);
/* This is safe as nc_psd is discarded at fn exit. */
nc_psd->owner_sid = &owner_sid;
nc_psd->group_sid = &group_sid;
security_info_sent |= (OWNER_SECURITY_INFORMATION|GROUP_SECURITY_INFORMATION);
psd = nc_psd;
}
status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
/* Get the full underlying sd, then hash. */
status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
fsp,
HASH_SECURITY_INFO,
&pdesc_next);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
status = hash_sd_sha256(pdesc_next, hash);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
if (DEBUGLEVEL >= 10) {
DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n",
fsp_str_dbg(fsp)));
NDR_PRINT_DEBUG(security_descriptor,
CONST_DISCARD(struct security_descriptor *,psd));
}
create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
store_acl_blob_fsp(handle, fsp, &blob);
return NT_STATUS_OK;
}