| Option Explicit Private Const FOLDER_PATH = "f:/Test" ' Success status of high level access control APIs
Private Const ERROR_SUCCESS = 0& ' Type of Securable Object we are operating in this sample code
Private Const SE_FILE_OBJECT = 1&
Const KEY_ALL_ACCESS = KEY_QUERY_VALUE + KEY_SET_VALUE + KEY_CREATE_SUB_KEY + KEY_ENUMERATE_SUB_KEYS + KEY_NOTIFY + KEY_CREATE_LINK + READ_CONTROL
' The Security Information constants required
Private Const DACL_SECURITY_INFORMATION = 4&
Private Const SET_ACCESS = 2& Private Enum SE_OBJECT_TYPE
SE_UNKNOWN_OBJECT_TYPE = 0&
SE_FILE_OBJECT = 1&
SE_SERVICE = 2&
SE_PRINTER = 3&
SE_REGISTRY_KEY = 4&
SE_LMSHARE = 5&
SE_KERNEL_OBJECT = 6&
SE_WINDOW_OBJECT = 7&
End Enum
' Standard access rights extracted from WinNT.h
Private Const SYNCHRONIZE = &H100000
Private Const READ_CONTROL = &H20000
Private Const WRITE_DAC = &H40000
Private Const WRITE_OWNER = &H80000
Private Const STANDARD_RIGHTS_READ = (READ_CONTROL)
Private Const STANDARD_RIGHTS_WRITE = (READ_CONTROL)
Private Const DELETE = &H10000 ' Generic access rights extracted from WinNT.h
Private Const GENERIC_ALL = &H10000000
Private Const GENERIC_EXECUTE = &H20000000
Private Const GENERIC_READ = &H80000000
Private Const GENERIC_WRITE = &H40000000 ' Inheritance Flags
Private Const CONTAINER_INHERIT_ACE = &H2
Private Const OBJECT_INHERIT_ACE = &H1 ' The TRUSTEE structure identifies the user account, group account, or logon session
' to which an ACE applies. The structure can use a name or a security identifier (SID)
' to identify the trustee. ' Access control APIs, such as SetEntriesInAcl and GetExplicitEntriesFromAcl, use this
' structure to identify the account associated with the access-control or audit-control
' information in an EXPLICIT_ACCESS structure.
Private Type TRUSTEE
pMultipleTrustee As Long
MultipleTrusteeOperation As Long
TrusteeForm As Long
TrusteeType As Long
ptstrName As String
End Type ' EXPLICIT_ACCESS structure that specifies access-control information for a specified
' trustee such as access mask as well as inheritance flags
Private Type EXPLICIT_ACCESS
grfAccessPermissions As Long
grfAccessMode As Long
grfInheritance As Long
pTRUSTEE As TRUSTEE
End Type ' High Level access control API declarations
Private Declare Sub BuildExplicitAccessWithName Lib "Advapi32.dll" Alias _
"BuildExplicitAccessWithNameA" _
(ea As Any, _
ByVal TrusteeName As String, _
ByVal AccessPermissions As Long, _
ByVal AccessMode As Integer, _
ByVal Inheritance As Long)
Private Declare Function SetEntriesInAcl Lib "Advapi32.dll" Alias _
"SetEntriesInAclA" _
(ByVal CountofExplicitEntries As Long, _
ea As Any, _
ByVal OldAcl As Long, _
NewAcl As Long) As Long Private Declare Function GetNamedSecurityInfo Lib "Advapi32.dll" Alias _
"GetNamedSecurityInfoA" _
(ByVal ObjName As String, _
ByVal SE_OBJECT_TYPE As Long, _
ByVal SecInfo As Long, _
ByVal pSid As Long, _
ByVal pSidGroup As Long, _
pDacl As Long, _
ByVal pSacl As Long, _
pSecurityDescriptor As Long) As Long
Private Declare Function SetNamedSecurityInfo Lib "Advapi32.dll" Alias _
"SetNamedSecurityInfoA" _
(ByVal ObjName As String, _
ByVal SE_OBJECT As Long, _
ByVal SecInfo As Long, _
ByVal pSid As Long, _
ByVal pSidGroup As Long, _
ByVal pDacl As Long, _
ByVal pSacl As Long) As Long Private Declare Function LocalFree Lib "kernel32" (ByVal hMem As Long) As Long Private Sub Command1_Click() Dim result As Long
Dim pSecDesc As Long
Dim ea As EXPLICIT_ACCESS
Dim pNewDACL As Long
Dim pOldDACL As Long
' Get the DACL information of the folder using GetNamedSecurityInfo() API.
' SE_FILE_OBJECT constant says that the named securable object is a file or folder
result = GetNamedSecurityInfo(FOLDER_PATH, SE_FILE_OBJECT, DACL_SECURITY_INFORMATION, 0&, 0&, pOldDACL, 0&, pSecDesc)
If result = ERROR_SUCCESS Then
' Construct an EXPLICIT_ACCESS structure for Everyone with GENERIC_ALL access that will apply for c:/test1
' as well as subfolder and files using BuildExplicitAccessWithName() API
BuildExplicitAccessWithName ea, "EVERYONE", GENERIC_ALL, SET_ACCESS, CONTAINER_INHERIT_ACE Or OBJECT_INHERIT_ACE
' Merge constructed EXPLICIT_ACCESS structure to the existing DACL and get an updated DACL in memory from
' SetEntriesInAcl() API
result = SetEntriesInAcl(1, ea, pOldDACL, pNewDACL)
If result = ERROR_SUCCESS Then
MsgBox "SetEntriesInAcl succeeded"
' Call SetNamedSecurityInfo() API with the updated DACL in memory to change the DACL of c:/test folder
result = SetNamedSecurityInfo(FOLDER_PATH, SE_FILE_OBJECT, DACL_SECURITY_INFORMATION, 0&, 0&, pNewDACL, 0&)
If result = ERROR_SUCCESS Then
MsgBox "SetNamedSecurityInfo succeeded"
Else
MsgBox "SetNamedSecurityInfo failed with error code : " & result
End If
' Free the memory allocated for the new DACL by the SetEntriesInAcl() API, using LocalFree() API
LocalFree pNewDACL
Else
MsgBox "SetEntriesInAcl failed with error code : " & result
End If
' Free the memory allocated for the security descriptor by the GetNamedSecurityInfo() API, using LocalFree() API
LocalFree pSecDesc
Else
MsgBox "GetNamedSecurityInfo failed with error code : " & result
End If
End Sub |
