749 lines
22 KiB
C++
749 lines
22 KiB
C++
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/* security.cc: NT file access control functions
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Originaly written by Gunther Ebert, gunther.ebert@ixos-leipzig.de
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Completely rewritten by Corinna Vinschen <corinna@vinschen.de>
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This file is part of Cygwin.
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This software is a copyrighted work licensed under the terms of the
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Cygwin license. Please consult the file "CYGWIN_LICENSE" for
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details. */
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#include "winsup.h"
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#include <unistd.h>
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#include <stdlib.h>
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#include <cygwin/acl.h>
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#include "cygerrno.h"
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#include "security.h"
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#include "path.h"
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#include "fhandler.h"
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#include "dtable.h"
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#include "pinfo.h"
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#include "cygheap.h"
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#include "ntdll.h"
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#include "tls_pbuf.h"
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#include <aclapi.h>
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#define ALL_SECURITY_INFORMATION (DACL_SECURITY_INFORMATION \
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| GROUP_SECURITY_INFORMATION \
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| OWNER_SECURITY_INFORMATION)
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static GENERIC_MAPPING NO_COPY_RO file_mapping = { FILE_GENERIC_READ,
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FILE_GENERIC_WRITE,
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FILE_GENERIC_EXECUTE,
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FILE_ALL_ACCESS };
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LONG
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get_file_sd (HANDLE fh, path_conv &pc, security_descriptor &sd,
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bool justcreated)
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{
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NTSTATUS status = STATUS_SUCCESS;
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OBJECT_ATTRIBUTES attr;
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IO_STATUS_BLOCK io;
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ULONG len = SD_MAXIMUM_SIZE, rlen;
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/* Allocate space for the security descriptor. */
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if (!sd.malloc (len))
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{
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set_errno (ENOMEM);
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return -1;
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}
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/* Try to fetch the security descriptor if the handle is valid. */
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if (fh)
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{
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status = NtQuerySecurityObject (fh, ALL_SECURITY_INFORMATION,
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sd, len, &rlen);
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if (!NT_SUCCESS (status))
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debug_printf ("NtQuerySecurityObject (%S), status %y",
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pc.get_nt_native_path (), status);
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}
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/* If the handle was NULL, or fetching with the original handle didn't work,
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try to reopen the file with READ_CONTROL and fetch the security descriptor
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using that handle. */
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if (!fh || !NT_SUCCESS (status))
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{
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status = NtOpenFile (&fh, READ_CONTROL,
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fh ? pc.init_reopen_attr (attr, fh)
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: pc.get_object_attr (attr, sec_none_nih),
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&io, FILE_SHARE_VALID_FLAGS,
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FILE_OPEN_FOR_BACKUP_INTENT
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| pc.is_known_reparse_point ()
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? FILE_OPEN_REPARSE_POINT : 0);
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if (!NT_SUCCESS (status))
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{
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sd.free ();
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__seterrno_from_nt_status (status);
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return -1;
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}
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status = NtQuerySecurityObject (fh, ALL_SECURITY_INFORMATION,
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sd, len, &rlen);
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NtClose (fh);
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if (!NT_SUCCESS (status))
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{
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sd.free ();
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__seterrno_from_nt_status (status);
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return -1;
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}
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}
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/* We have a security descriptor now. Unfortunately, if you want to know
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if an ACE is inherited from the parent object, this isn't sufficient.
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In the simple case, the SDs control word contains one of the
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SE_DACL_AUTO_INHERITED or SE_DACL_PROTECTED flags, or at least one of
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the ACEs has the INHERITED_ACE flag set. In all of these cases we
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know the DACL has been inherited.
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If none of these flags is set in the SD, the information whether
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or not an ACE has been inherited is not available in the DACL of the
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object. In this case GetSecurityInfo fetches the SD from the parent
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directory and tests if the object's SD contains inherited ACEs from the
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parent.
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Note that we're not testing the SE_DACL_AUTO_INHERITED and
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SE_DACL_PROTECTED flags here because we know the state the file's SD
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is in. Since we're creating all files with a NULL descriptor, the DACL
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is either inherited from the parent, or it's the default DACL. In
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neither case, one of these flags is set.
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For speed, we're not calling RtlConvertToAutoInheritSecurityObject
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anymore (but keep the code here for reference). Rather we just test
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if one of the parent's ACEs is inheritable. If so, we know we inherited
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it and set the SE_DACL_AUTO_INHERITED flag. If not, we may assume our
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object's DACL is the default DACL.
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This functionality is slow and the extra information is only required
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when the file has been created and the permissions are about to be set
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to POSIX permissions. Therefore we only use it in case the file just
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got created. */
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if (justcreated)
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{
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PACL dacl;
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BOOLEAN exists, def;
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ACCESS_ALLOWED_ACE *ace;
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UNICODE_STRING dirname;
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PSECURITY_DESCRIPTOR psd;
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tmp_pathbuf tp;
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/* Open the parent directory with READ_CONTROL... */
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RtlSplitUnicodePath (pc.get_nt_native_path (), &dirname, NULL);
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InitializeObjectAttributes (&attr, &dirname, pc.objcaseinsensitive (),
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NULL, NULL);
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status = NtOpenFile (&fh, READ_CONTROL, &attr, &io,
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FILE_SHARE_VALID_FLAGS,
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FILE_OPEN_FOR_BACKUP_INTENT
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| FILE_OPEN_REPARSE_POINT);
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if (!NT_SUCCESS (status))
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{
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debug_printf ("NtOpenFile (%S), status %y", &dirname, status);
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return 0;
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}
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/* ... fetch the parent's security descriptor ... */
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psd = (PSECURITY_DESCRIPTOR) tp.w_get ();
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status = NtQuerySecurityObject (fh, ALL_SECURITY_INFORMATION,
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psd, len, &rlen);
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NtClose (fh);
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if (!NT_SUCCESS (status))
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{
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debug_printf ("NtQuerySecurityObject (%S), status %y",
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&dirname, status);
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return 0;
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}
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#if 0
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/* ... and create a new security descriptor in which all inherited ACEs
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are marked with the INHERITED_ACE flag. For a description of the
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undocumented RtlConvertToAutoInheritSecurityObject function from
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ntdll.dll see the MSDN man page for the advapi32 function
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ConvertToAutoInheritPrivateObjectSecurity. Fortunately the latter
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is just a shim. */
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PSECURITY_DESCRIPTOR nsd;
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status = RtlConvertToAutoInheritSecurityObject (psd, sd, &nsd, NULL,
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pc.isdir (),
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&file_mapping);
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if (!NT_SUCCESS (status))
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{
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debug_printf ("RtlConvertToAutoInheritSecurityObject (%S), status %y",
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&dirname, status);
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return 0;
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}
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/* Eventually copy the new security descriptor into sd and delete the
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original one created by RtlConvertToAutoInheritSecurityObject from
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the heap. */
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len = RtlLengthSecurityDescriptor (nsd);
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memcpy ((PSECURITY_DESCRIPTOR) sd, nsd, len);
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RtlDeleteSecurityObject (&nsd);
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#else
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/* ... and check the parent descriptor for inheritable ACEs matching
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our current object type (file/dir). The simple truth in our case
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is, either the parent dir had inheritable ACEs and all our ACEs are
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inherited, or the parent dir didn't have inheritable ACEs and all
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our ACEs are taken from the default DACL. */
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bool inherited = false;
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BYTE search_flags = pc.isdir () ? SUB_CONTAINERS_AND_OBJECTS_INHERIT
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: SUB_OBJECTS_ONLY_INHERIT;
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if (NT_SUCCESS (RtlGetDaclSecurityDescriptor (psd, &exists, &dacl, &def))
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&& exists && dacl)
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for (ULONG idx = 0; idx < dacl->AceCount; ++idx)
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if (NT_SUCCESS (RtlGetAce (dacl, idx, (PVOID *) &ace))
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&& (ace->Header.AceFlags & search_flags))
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{
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inherited = true;
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break;
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}
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/* Then, if the parent descriptor contained inheritable ACEs, we mark
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the SD as SE_DACL_AUTO_INHERITED. Note that this requires the
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matching check in get_posix_access. If we ever revert to
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RtlConvertToAutoInheritSecurityObject, the check in get_posix_access
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has to test every single ACE for the INHERITED_ACE flag again. */
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if (inherited
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&& NT_SUCCESS (RtlGetDaclSecurityDescriptor (sd, &exists, &dacl,
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&def))
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&& exists && dacl)
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RtlSetControlSecurityDescriptor (sd, SE_DACL_AUTO_INHERITED,
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SE_DACL_AUTO_INHERITED);
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#endif
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}
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return 0;
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}
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LONG
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set_file_sd (HANDLE fh, path_conv &pc, security_descriptor &sd, bool is_chown)
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{
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NTSTATUS status = STATUS_SUCCESS;
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int retry = 0;
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int res = -1;
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for (; retry < 2; ++retry)
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{
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if (fh)
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{
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status = NtSetSecurityObject (fh,
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is_chown ? ALL_SECURITY_INFORMATION
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: DACL_SECURITY_INFORMATION,
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sd);
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if (NT_SUCCESS (status))
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{
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res = 0;
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break;
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}
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}
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if (!retry)
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{
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OBJECT_ATTRIBUTES attr;
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IO_STATUS_BLOCK io;
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status = NtOpenFile (&fh, (is_chown ? WRITE_OWNER : 0) | WRITE_DAC,
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fh ? pc.init_reopen_attr (attr, fh)
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: pc.get_object_attr (attr, sec_none_nih),
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&io,
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FILE_SHARE_VALID_FLAGS,
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FILE_OPEN_FOR_BACKUP_INTENT
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| pc.is_known_reparse_point ()
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? FILE_OPEN_REPARSE_POINT : 0);
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if (!NT_SUCCESS (status))
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{
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fh = NULL;
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break;
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}
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}
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}
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if (retry && fh)
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NtClose (fh);
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if (!NT_SUCCESS (status))
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__seterrno_from_nt_status (status);
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return res;
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}
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static int
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get_reg_sd (HANDLE handle, security_descriptor &sd_ret)
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{
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LONG ret;
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DWORD len = 0;
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ret = RegGetKeySecurity ((HKEY) handle, ALL_SECURITY_INFORMATION,
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sd_ret, &len);
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if (ret == ERROR_INSUFFICIENT_BUFFER)
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{
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if (!sd_ret.malloc (len))
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set_errno (ENOMEM);
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else
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ret = RegGetKeySecurity ((HKEY) handle, ALL_SECURITY_INFORMATION,
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sd_ret, &len);
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}
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if (ret != ERROR_SUCCESS)
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{
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__seterrno ();
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return -1;
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}
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return 0;
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}
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int
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get_reg_attribute (HKEY hkey, mode_t *attribute, uid_t *uidret,
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gid_t *gidret)
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{
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security_descriptor sd;
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if (!get_reg_sd (hkey, sd))
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{
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get_posix_access (sd, attribute, uidret, gidret, NULL, 0);
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return 0;
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}
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/* The entries are already set to default values */
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return -1;
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}
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int
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get_file_attribute (HANDLE handle, path_conv &pc,
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mode_t *attribute, uid_t *uidret, gid_t *gidret)
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{
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if (pc.has_acls ())
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{
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security_descriptor sd;
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if (!get_file_sd (handle, pc, sd, false))
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{
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get_posix_access (sd, attribute, uidret, gidret, NULL, 0);
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return 0;
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}
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/* ENOSYS is returned by get_file_sd if fetching the DACL from a remote
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share returns STATUS_INVALID_NETWORK_RESPONSE, which in turn is
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converted to ERROR_BAD_NET_RESP. This potentially occurs when trying
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to fetch DACLs from a NT4 machine which is not part of the domain of
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the requesting machine. */
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else if (get_errno () != ENOSYS)
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{
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if (uidret)
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*uidret = ILLEGAL_UID;
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if (gidret)
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*gidret = ILLEGAL_GID;
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return -1;
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}
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}
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if (uidret)
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*uidret = myself->uid;
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if (gidret)
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*gidret = myself->gid;
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return -1;
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}
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bool
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add_access_allowed_ace (PACL acl, DWORD attributes, PSID sid, size_t &len_add,
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DWORD inherit)
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{
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NTSTATUS status = RtlAddAccessAllowedAceEx (acl, ACL_REVISION, inherit,
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|
attributes, sid);
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if (!NT_SUCCESS (status))
|
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{
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|
__seterrno_from_nt_status (status);
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return false;
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|
}
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len_add += sizeof (ACCESS_ALLOWED_ACE) - sizeof (DWORD) + RtlLengthSid (sid);
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return true;
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|
}
|
||
|
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||
|
bool
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add_access_denied_ace (PACL acl, DWORD attributes, PSID sid, size_t &len_add,
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|
DWORD inherit)
|
||
|
{
|
||
|
NTSTATUS status = RtlAddAccessDeniedAceEx (acl, ACL_REVISION, inherit,
|
||
|
attributes, sid);
|
||
|
if (!NT_SUCCESS (status))
|
||
|
{
|
||
|
__seterrno_from_nt_status (status);
|
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|
return false;
|
||
|
}
|
||
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len_add += sizeof (ACCESS_DENIED_ACE) - sizeof (DWORD) + RtlLengthSid (sid);
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
void
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|
set_security_attribute (path_conv &pc, int attribute, PSECURITY_ATTRIBUTES psa,
|
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|
security_descriptor &sd)
|
||
|
{
|
||
|
psa->lpSecurityDescriptor = sd.malloc (SECURITY_DESCRIPTOR_MIN_LENGTH);
|
||
|
RtlCreateSecurityDescriptor ((PSECURITY_DESCRIPTOR) psa->lpSecurityDescriptor,
|
||
|
SECURITY_DESCRIPTOR_REVISION);
|
||
|
psa->lpSecurityDescriptor = set_posix_access (attribute, geteuid32 (),
|
||
|
getegid32 (), NULL, 0,
|
||
|
sd, false);
|
||
|
}
|
||
|
|
||
|
int
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||
|
get_object_sd (HANDLE handle, security_descriptor &sd)
|
||
|
{
|
||
|
ULONG len = 0;
|
||
|
NTSTATUS status;
|
||
|
|
||
|
status = NtQuerySecurityObject (handle, ALL_SECURITY_INFORMATION,
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|
sd, len, &len);
|
||
|
if (status != STATUS_BUFFER_TOO_SMALL)
|
||
|
{
|
||
|
__seterrno_from_nt_status (status);
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|
return -1;
|
||
|
}
|
||
|
if (!sd.malloc (len))
|
||
|
{
|
||
|
set_errno (ENOMEM);
|
||
|
return -1;
|
||
|
}
|
||
|
status = NtQuerySecurityObject (handle, ALL_SECURITY_INFORMATION,
|
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|
sd, len, &len);
|
||
|
if (!NT_SUCCESS (status))
|
||
|
{
|
||
|
__seterrno_from_nt_status (status);
|
||
|
return -1;
|
||
|
}
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
int
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||
|
get_object_attribute (HANDLE handle, uid_t *uidret, gid_t *gidret,
|
||
|
mode_t *attribute)
|
||
|
{
|
||
|
security_descriptor sd;
|
||
|
|
||
|
if (get_object_sd (handle, sd))
|
||
|
return -1;
|
||
|
return get_posix_access (sd, attribute, uidret, gidret, NULL, 0)
|
||
|
>= 0 ? 0 : -1;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
create_object_sd_from_attribute (uid_t uid, gid_t gid, mode_t attribute,
|
||
|
security_descriptor &sd)
|
||
|
{
|
||
|
return set_posix_access (attribute, uid, gid, NULL, 0, sd, false)
|
||
|
? 0 : -1;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
set_object_sd (HANDLE handle, security_descriptor &sd, bool chown)
|
||
|
{
|
||
|
NTSTATUS status;
|
||
|
status = NtSetSecurityObject (handle, chown ? ALL_SECURITY_INFORMATION
|
||
|
: DACL_SECURITY_INFORMATION, sd);
|
||
|
if (!NT_SUCCESS (status))
|
||
|
{
|
||
|
__seterrno_from_nt_status (status);
|
||
|
return -1;
|
||
|
}
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
set_object_attribute (HANDLE handle, uid_t uid, gid_t gid, mode_t attribute)
|
||
|
{
|
||
|
security_descriptor sd;
|
||
|
|
||
|
if (create_object_sd_from_attribute (uid, gid, attribute, sd)
|
||
|
|| set_object_sd (handle, sd, uid != ILLEGAL_UID || gid != ILLEGAL_GID))
|
||
|
return -1;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
set_created_file_access (HANDLE handle, path_conv &pc, mode_t attr)
|
||
|
{
|
||
|
int ret = -1;
|
||
|
security_descriptor sd, sd_ret;
|
||
|
mode_t attr_rd;
|
||
|
uid_t uid;
|
||
|
gid_t gid;
|
||
|
tmp_pathbuf tp;
|
||
|
aclent_t *aclp;
|
||
|
int nentries, idx;
|
||
|
bool std_acl;
|
||
|
|
||
|
if (!get_file_sd (handle, pc, sd, true))
|
||
|
{
|
||
|
attr |= S_JUSTCREATED;
|
||
|
if (pc.isdir ())
|
||
|
attr |= S_IFDIR;
|
||
|
attr_rd = attr;
|
||
|
aclp = (aclent_t *) tp.c_get ();
|
||
|
if ((nentries = get_posix_access (sd, &attr_rd, &uid, &gid, aclp,
|
||
|
MAX_ACL_ENTRIES, &std_acl)) >= 0)
|
||
|
{
|
||
|
if (S_ISLNK (attr))
|
||
|
{
|
||
|
/* Symlinks always get the request POSIX perms. */
|
||
|
aclp[0].a_perm = (attr >> 6) & S_IRWXO;
|
||
|
if ((idx = searchace (aclp, nentries, GROUP_OBJ)) >= 0)
|
||
|
aclp[idx].a_perm = (attr >> 3) & S_IRWXO;
|
||
|
if ((idx = searchace (aclp, nentries, CLASS_OBJ)) >= 0)
|
||
|
aclp[idx].a_perm = (attr >> 3) & S_IRWXO;
|
||
|
if ((idx = searchace (aclp, nentries, OTHER_OBJ)) >= 0)
|
||
|
aclp[idx].a_perm = attr & S_IRWXO;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
/* Overwrite ACL permissions as required by POSIX 1003.1e
|
||
|
draft 17. */
|
||
|
aclp[0].a_perm &= (attr >> 6) & S_IRWXO;
|
||
|
if ((idx = searchace (aclp, nentries, CLASS_OBJ)) >= 0)
|
||
|
aclp[idx].a_perm &= (attr >> 3) & S_IRWXO;
|
||
|
if (std_acl
|
||
|
&& (idx = searchace (aclp, nentries, GROUP_OBJ)) >= 0)
|
||
|
aclp[idx].a_perm &= (attr >> 3) & S_IRWXO;
|
||
|
if ((idx = searchace (aclp, nentries, OTHER_OBJ)) >= 0)
|
||
|
aclp[idx].a_perm &= attr & S_IRWXO;
|
||
|
}
|
||
|
/* Construct appropriate inherit attribute for new directories.
|
||
|
Basically we do this only for the sake of non-Cygwin applications.
|
||
|
Cygwin applications don't need these. Additionally, if the
|
||
|
S_ISGID bit is set, propagate it. */
|
||
|
if (S_ISDIR (attr))
|
||
|
{
|
||
|
if (searchace (aclp, nentries, DEF_USER_OBJ) < 0)
|
||
|
{
|
||
|
aclp[nentries].a_type = DEF_USER_OBJ;
|
||
|
aclp[nentries].a_id = ILLEGAL_UID;
|
||
|
aclp[nentries++].a_perm = (attr >> 6) & S_IRWXO;
|
||
|
}
|
||
|
if (searchace (aclp, nentries, DEF_GROUP_OBJ) < 0)
|
||
|
{
|
||
|
aclp[nentries].a_type = DEF_GROUP_OBJ;
|
||
|
aclp[nentries].a_id = ILLEGAL_GID;
|
||
|
aclp[nentries++].a_perm = (attr >> 3) & S_IRWXO;
|
||
|
}
|
||
|
if (searchace (aclp, nentries, DEF_OTHER_OBJ) < 0)
|
||
|
{
|
||
|
aclp[nentries].a_type = DEF_OTHER_OBJ;
|
||
|
aclp[nentries].a_id = ILLEGAL_UID;
|
||
|
aclp[nentries++].a_perm = attr & S_IRWXO;
|
||
|
}
|
||
|
if (attr_rd & S_ISGID)
|
||
|
attr |= S_ISGID;
|
||
|
}
|
||
|
if (set_posix_access (attr, uid, gid, aclp, nentries, sd_ret,
|
||
|
pc.fs_is_samba ()))
|
||
|
ret = set_file_sd (handle, pc, sd_ret, attr_rd & S_ISGID);
|
||
|
}
|
||
|
}
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static int
|
||
|
check_access (security_descriptor &sd, GENERIC_MAPPING &mapping,
|
||
|
ACCESS_MASK desired, int flags, bool effective)
|
||
|
{
|
||
|
int ret = -1;
|
||
|
NTSTATUS status, allow;
|
||
|
ACCESS_MASK granted;
|
||
|
DWORD plen = sizeof (PRIVILEGE_SET) + 3 * sizeof (LUID_AND_ATTRIBUTES);
|
||
|
PPRIVILEGE_SET pset = (PPRIVILEGE_SET) alloca (plen);
|
||
|
HANDLE tok = ((effective && cygheap->user.issetuid ())
|
||
|
? cygheap->user.imp_token ()
|
||
|
: hProcImpToken);
|
||
|
|
||
|
if (!tok)
|
||
|
{
|
||
|
if (!DuplicateTokenEx (hProcToken, MAXIMUM_ALLOWED, NULL,
|
||
|
SecurityImpersonation, TokenImpersonation,
|
||
|
&hProcImpToken))
|
||
|
{
|
||
|
__seterrno ();
|
||
|
return ret;
|
||
|
}
|
||
|
tok = hProcImpToken;
|
||
|
}
|
||
|
|
||
|
status = NtAccessCheck (sd, tok, desired, &mapping, pset, &plen, &granted,
|
||
|
&allow);
|
||
|
if (!NT_SUCCESS (status))
|
||
|
__seterrno ();
|
||
|
else if (!NT_SUCCESS (allow))
|
||
|
{
|
||
|
/* CV, 2006-10-16: Now, that's really weird. Imagine a user who has no
|
||
|
standard access to a file, but who has backup and restore privileges
|
||
|
and these privileges are enabled in the access token. One would
|
||
|
expect that the AccessCheck function takes this into consideration
|
||
|
when returning the access status. Otherwise, why bother with the
|
||
|
pset parameter, right?
|
||
|
But not so. AccessCheck actually returns a status of "false" here,
|
||
|
even though opening a file with backup resp. restore intent
|
||
|
naturally succeeds for this user. This definitely spoils the results
|
||
|
of access(2) for administrative users or the SYSTEM account. So, in
|
||
|
case the access check fails, another check against the user's
|
||
|
backup/restore privileges has to be made. Sigh. */
|
||
|
int granted_flags = 0;
|
||
|
BOOLEAN has_priv;
|
||
|
|
||
|
if (flags & R_OK)
|
||
|
{
|
||
|
pset->PrivilegeCount = 1;
|
||
|
pset->Control = 0;
|
||
|
pset->Privilege[0].Luid.HighPart = 0L;
|
||
|
pset->Privilege[0].Luid.LowPart = SE_BACKUP_PRIVILEGE;
|
||
|
pset->Privilege[0].Attributes = 0;
|
||
|
status = NtPrivilegeCheck (tok, pset, &has_priv);
|
||
|
if (NT_SUCCESS (status) && has_priv)
|
||
|
granted_flags |= R_OK;
|
||
|
}
|
||
|
if (flags & W_OK)
|
||
|
{
|
||
|
pset->PrivilegeCount = 1;
|
||
|
pset->Control = 0;
|
||
|
pset->Privilege[0].Luid.HighPart = 0L;
|
||
|
pset->Privilege[0].Luid.LowPart = SE_RESTORE_PRIVILEGE;
|
||
|
pset->Privilege[0].Attributes = 0;
|
||
|
status = NtPrivilegeCheck (tok, pset, &has_priv);
|
||
|
if (NT_SUCCESS (status) && has_priv)
|
||
|
granted_flags |= W_OK;
|
||
|
}
|
||
|
if (granted_flags == flags)
|
||
|
ret = 0;
|
||
|
else
|
||
|
set_errno (EACCES);
|
||
|
}
|
||
|
else
|
||
|
ret = 0;
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
/* Samba override. Check security descriptor for Samba UNIX user and group
|
||
|
accounts and check if we have an RFC 2307 mapping to a Windows account.
|
||
|
Create a new security descriptor with all of the UNIX accounts with
|
||
|
valid mapping replaced with their Windows counterpart. */
|
||
|
static void
|
||
|
convert_samba_sd (security_descriptor &sd_ret)
|
||
|
{
|
||
|
NTSTATUS status;
|
||
|
BOOLEAN dummy;
|
||
|
PSID sid;
|
||
|
cygsid owner;
|
||
|
cygsid group;
|
||
|
SECURITY_DESCRIPTOR sd;
|
||
|
cyg_ldap cldap;
|
||
|
tmp_pathbuf tp;
|
||
|
PACL acl, oacl;
|
||
|
size_t acl_len;
|
||
|
PACCESS_ALLOWED_ACE ace;
|
||
|
|
||
|
if (!NT_SUCCESS (RtlGetOwnerSecurityDescriptor (sd_ret, &sid, &dummy)))
|
||
|
return;
|
||
|
owner = sid;
|
||
|
if (!NT_SUCCESS (RtlGetGroupSecurityDescriptor (sd_ret, &sid, &dummy)))
|
||
|
return;
|
||
|
group = sid;
|
||
|
|
||
|
if (sid_id_auth (owner) == 22)
|
||
|
{
|
||
|
struct passwd *pwd;
|
||
|
uid_t uid = owner.get_uid (&cldap);
|
||
|
if (uid < UNIX_POSIX_OFFSET && (pwd = internal_getpwuid (uid)))
|
||
|
owner.getfrompw (pwd);
|
||
|
}
|
||
|
if (sid_id_auth (group) == 22)
|
||
|
{
|
||
|
struct group *grp;
|
||
|
gid_t gid = group.get_gid (&cldap);
|
||
|
if (gid < UNIX_POSIX_OFFSET && (grp = internal_getgrgid (gid)))
|
||
|
group.getfromgr (grp);
|
||
|
}
|
||
|
|
||
|
if (!NT_SUCCESS (RtlGetDaclSecurityDescriptor (sd_ret, &dummy,
|
||
|
&oacl, &dummy)))
|
||
|
return;
|
||
|
acl = (PACL) tp.w_get ();
|
||
|
RtlCreateAcl (acl, ACL_MAXIMUM_SIZE, ACL_REVISION);
|
||
|
acl_len = sizeof (ACL);
|
||
|
|
||
|
for (DWORD i = 0; i < oacl->AceCount; ++i)
|
||
|
if (NT_SUCCESS (RtlGetAce (oacl, i, (PVOID *) &ace)))
|
||
|
{
|
||
|
cygsid ace_sid ((PSID) &ace->SidStart);
|
||
|
if (sid_id_auth (ace_sid) == 22)
|
||
|
{
|
||
|
if (sid_sub_auth (ace_sid, 0) == 1) /* user */
|
||
|
{
|
||
|
struct passwd *pwd;
|
||
|
uid_t uid = ace_sid.get_uid (&cldap);
|
||
|
if (uid < UNIX_POSIX_OFFSET && (pwd = internal_getpwuid (uid)))
|
||
|
ace_sid.getfrompw (pwd);
|
||
|
}
|
||
|
else if (sid_sub_auth (ace_sid, 0) == 2) /* group */
|
||
|
{
|
||
|
struct group *grp;
|
||
|
gid_t gid = ace_sid.get_gid (&cldap);
|
||
|
if (gid < UNIX_POSIX_OFFSET && (grp = internal_getgrgid (gid)))
|
||
|
ace_sid.getfromgr (grp);
|
||
|
}
|
||
|
}
|
||
|
if (!add_access_allowed_ace (acl, ace->Mask, ace_sid, acl_len,
|
||
|
ace->Header.AceFlags))
|
||
|
return;
|
||
|
}
|
||
|
acl->AclSize = acl_len;
|
||
|
|
||
|
RtlCreateSecurityDescriptor (&sd, SECURITY_DESCRIPTOR_REVISION);
|
||
|
RtlSetControlSecurityDescriptor (&sd, SE_DACL_PROTECTED, SE_DACL_PROTECTED);
|
||
|
RtlSetOwnerSecurityDescriptor (&sd, owner, FALSE);
|
||
|
RtlSetGroupSecurityDescriptor (&sd, group, FALSE);
|
||
|
|
||
|
status = RtlSetDaclSecurityDescriptor (&sd, TRUE, acl, FALSE);
|
||
|
if (!NT_SUCCESS (status))
|
||
|
return;
|
||
|
DWORD sd_size = 0;
|
||
|
status = RtlAbsoluteToSelfRelativeSD (&sd, sd_ret, &sd_size);
|
||
|
if (sd_size > 0 && sd_ret.malloc (sd_size))
|
||
|
RtlAbsoluteToSelfRelativeSD (&sd, sd_ret, &sd_size);
|
||
|
}
|
||
|
|
||
|
int
|
||
|
check_file_access (path_conv &pc, int flags, bool effective)
|
||
|
{
|
||
|
security_descriptor sd;
|
||
|
int ret = -1;
|
||
|
ACCESS_MASK desired = 0;
|
||
|
if (flags & R_OK)
|
||
|
desired |= FILE_READ_DATA;
|
||
|
if (flags & W_OK)
|
||
|
desired |= FILE_WRITE_DATA;
|
||
|
if (flags & X_OK)
|
||
|
desired |= FILE_EXECUTE;
|
||
|
if (!get_file_sd (pc.handle (), pc, sd, false))
|
||
|
{
|
||
|
/* Tweak Samba security descriptor as necessary. */
|
||
|
if (pc.fs_is_samba ())
|
||
|
convert_samba_sd (sd);
|
||
|
ret = check_access (sd, file_mapping, desired, flags, effective);
|
||
|
}
|
||
|
debug_printf ("flags %y, ret %d", flags, ret);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
check_registry_access (HANDLE hdl, int flags, bool effective)
|
||
|
{
|
||
|
security_descriptor sd;
|
||
|
int ret = -1;
|
||
|
static GENERIC_MAPPING NO_COPY_RO reg_mapping = { KEY_READ,
|
||
|
KEY_WRITE,
|
||
|
KEY_EXECUTE,
|
||
|
KEY_ALL_ACCESS };
|
||
|
ACCESS_MASK desired = 0;
|
||
|
if (flags & R_OK)
|
||
|
desired |= KEY_ENUMERATE_SUB_KEYS;
|
||
|
if (flags & W_OK)
|
||
|
desired |= KEY_SET_VALUE;
|
||
|
if (flags & X_OK)
|
||
|
desired |= KEY_QUERY_VALUE;
|
||
|
|
||
|
if ((HKEY) hdl == HKEY_PERFORMANCE_DATA)
|
||
|
/* RegGetKeySecurity() always fails with ERROR_INVALID_HANDLE. */
|
||
|
ret = 0;
|
||
|
else if (!get_reg_sd (hdl, sd))
|
||
|
ret = check_access (sd, reg_mapping, desired, flags, effective);
|
||
|
|
||
|
/* As long as we can't write the registry... */
|
||
|
if (flags & W_OK)
|
||
|
{
|
||
|
set_errno (EROFS);
|
||
|
ret = -1;
|
||
|
}
|
||
|
debug_printf ("flags %y, ret %d", flags, ret);
|
||
|
return ret;
|
||
|
}
|