Setting permissions on shared folders?

[chris128]

Well I'm still working on it and I'll post the results here if I do get it working, here's what I've got currently for anyone else that wants to try and get it working or offer any suggestions all of the API calls work fine and seem to populate the relevant structures correctly and dont return any error codes, right up until the call to NetShareAdd at the end which returns ERROR_INVALID_PARAMETER and sets the parm_err argument to 501 (this is supposed to point to which member of the SHARE_INFO_502 structure is causing the invalid parameter error but there are only 10 members so 501 isnt much use!).

#Region "Constants"
 
    Const STYPE_DISKTREE As UInteger = 0
    Const SECURITY_DESCRIPTOR_REVISION As UInteger = 1
    Const ACL_REVISION As UInteger = 2
    Const NO_INHERITANCE As UInteger = 0
    Const ACCESS_READ As Integer = &H1
    Const ACCESS_WRITE As Integer = &H2
    Const ACCESS_CREATE As Integer = &H4
    Const ACCESS_EXEC As Integer = &H8
    Const ACCESS_DELETE As Integer = &H10
    Const ACCESS_ATRIB As Integer = &H20
    Const ACCESS_PERM As Integer = &H40
    Const ACCESS_ALL As Integer = &H7F
#End Region
 
 
#Region "Enums"
 
    Public Enum NET_API_STATUS As Integer
        NERR_Success = 0
        ERROR_ACCESS_DENIED = 5
        ERROR_INVALID_PARAMETER = 87
        ERROR_INVALID_NAME = 123
        ERROR_INVALID_LEVEL = 124
        NERR_UnknownDevDir = 2116
        NERR_RedirectedPath = 2117
        NERR_DuplicateShare = 2118
        NERR_BufTooSmall = 2123
    End Enum
 
    Public Enum ACCESS_MODE As UInteger
        NOT_USED_ACCESS = 0
        GRANT_ACCESS = 1
        SET_ACCESS = 2
        DENY_ACCESS = 3
        REVOKE_ACCESS = 4
        SET_AUDIT_SUCCESS = 5
        SET_AUDIT_FAILURE = 6
    End Enum
 
    Public Enum MULTIPLE_TRUSTEE_OPERATION As UInteger
        NO_MULTIPLE_TRUSTEE = 0
        TRUSTEE_IS_IMPERSONATE = 1
    End Enum
 
    Public Enum TRUSTEE_FORM As UInteger
        TRUSTEE_IS_SID = 0
        TRUSTEE_IS_NAME = 1
        TRUSTEE_BAD_FORM = 2
        TRUSTEE_IS_OBJECTS_AND_SID = 3
        TRUSTEE_IS_OBJECTS_AND_NAME = 4
    End Enum
 
    Public Enum TRUSTEE_TYPE As UInteger
        TRUSTEE_IS_UNKNOWN = 0
        TRUSTEE_IS_USER = 1
        TRUSTEE_IS_GROUP = 2
        TRUSTEE_IS_DOMAIN = 3
        TRUSTEE_IS_ALIAS = 4
        TRUSTEE_IS_WELL_KNOWN_GROUP = 5
        TRUSTEE_IS_DELETED = 6
        TRUSTEE_IS_INVALID = 7
        TRUSTEE_IS_COMPUTER = 8
    End Enum
 
#End Region
 
 
#Region "Structures"
 
    <StructLayoutAttribute(LayoutKind.Sequential)> _
    Public Structure SHARE_INFO_502
        <MarshalAsAttribute(UnmanagedType.LPWStr)> Public shi502_netname As String
        Public shi502_type As UInteger
        <MarshalAsAttribute(UnmanagedType.LPWStr)> Public shi502_remark As String
        Public shi502_permissions As Integer
        Public shi502_max_uses As Integer
        Public shi502_current_uses As Integer
        <MarshalAsAttribute(UnmanagedType.LPWStr)> Public shi502_path As String
        <MarshalAsAttribute(UnmanagedType.LPWStr)> Public shi502_passwd As String
        Public shi502_reserved As Integer
        Public shi502_security_descriptor As SECURITY_DESCRIPTOR
    End Structure
 
    <StructLayoutAttribute(LayoutKind.Sequential)> _
    Public Structure SECURITY_DESCRIPTOR
        Public Revision As Byte
        Public Sbz1 As Byte
        Public Control As UShort
        Public Owner As IntPtr
        Public Group As IntPtr
        Public Sacl As IntPtr
        Public Dacl As IntPtr
    End Structure
 
    <StructLayoutAttribute(LayoutKind.Sequential)> _
    Public Structure ACL
        Public AclRevision As Byte
        Public Sbz1 As Byte
        Public AclSize As UShort
        Public AceCount As UShort
        Public Sbz2 As UShort
    End Structure
 
    <System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, Pack:=0)> _
    Public Structure EXPLICIT_ACCESS
        Public grfAccessPermissions As UInteger
        Public grfAccessMode As ACCESS_MODE
        Public grfInheritance As UInteger
        Public Trustee As TRUSTEE
    End Structure
 
    <System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, Pack:=0)> _
    Public Structure TRUSTEE
        Public pMultipleTrustee As UInteger
        Public MultipleTrusteeOperation As MULTIPLE_TRUSTEE_OPERATION
        Public TrusteeForm As TRUSTEE_FORM
        Public TrusteeType As TRUSTEE_TYPE
        <System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPTStr)> _
        Public ptstrName As String
    End Structure
 
#End Region
 
 
#Region "Native Methods"
 
    <DllImportAttribute("netapi32.dll", EntryPoint:="NetShareAdd")> _
    Public Shared Function NetShareAdd(<InAttribute(), MarshalAsAttribute(UnmanagedType.LPWStr)> ByVal servername As String, ByVal level As UInteger, <InAttribute()> ByRef buf As SHARE_INFO_502, <OutAttribute()> ByRef parm_err As Integer) As NET_API_STATUS
    End Function
 
    <System.Runtime.InteropServices.DllImportAttribute("advapi32.dll", EntryPoint:="InitializeSecurityDescriptor")> _
    Public Shared Function InitializeSecurityDescriptor(ByRef pSecurityDescriptor As SECURITY_DESCRIPTOR, ByVal dwRevision As UInteger) As UInteger
    End Function
 
    <System.Runtime.InteropServices.DllImportAttribute("Advapi32.dll", EntryPoint:="SetEntriesInAclW")> _
    Public Shared Function SetEntriesInAcl(ByVal cCountOfExplicitEntries As Integer, _
                                           <System.Runtime.InteropServices.InAttribute()> ByRef pListOfExplicitEntries As EXPLICIT_ACCESS, <System.Runtime.InteropServices.InAttribute()> ByVal OldAcl As System.IntPtr, ByRef NewAcl As System.IntPtr) As UInteger
    End Function
 
    <System.Runtime.InteropServices.DllImportAttribute("Advapi32.dll", EntryPoint:="BuildExplicitAccessWithNameW")> _
    Public Shared Sub BuildExplicitAccessWithName(ByRef pExplicitAccess As EXPLICIT_ACCESS, <InAttribute()> ByVal pTrusteeName As IntPtr, ByVal AccessPermissions As UInteger, ByVal AccessMode As UInteger, ByVal Inheritance As UInteger)
    End Sub
 
    <System.Runtime.InteropServices.DllImportAttribute("advapi32.dll", EntryPoint:="SetSecurityDescriptorDacl")> _
    Public Shared Function SetSecurityDescriptorDacl(ByRef pSecurityDescriptor As SECURITY_DESCRIPTOR, <MarshalAsAttribute(UnmanagedType.Bool)> _
                                                     ByVal bDaclPresent As Boolean, <InAttribute()> ByVal pDacl As System.IntPtr, <MarshalAsAttribute(UnmanagedType.Bool)> ByVal bDaclDefaulted As Boolean) As UInteger
    End Function
 
    <DllImportAttribute("advapi32.dll", EntryPoint:="IsValidSecurityDescriptor")> _
    Public Shared Function IsValidSecurityDesctiptor(ByRef pSecurityDescriptor As SECURITY_DESCRIPTOR) As UInteger
    End Function
 
#End Region
 
 
#Region "Managed Methods"
 
    Private Sub CreateShare(ByVal FullUsername As String)
        Dim ea As EXPLICIT_ACCESS = Nothing
        Dim AccountNamePtr As IntPtr = Marshal.StringToHGlobalUni(FullUsername)
        BuildExplicitAccessWithName(ea, AccountNamePtr, ACCESS_READ, ACCESS_MODE.SET_ACCESS, NO_INHERITANCE)
 
        Dim AclPtr As IntPtr
        Dim SetEntriesResult As UInteger = SetEntriesInAcl(1, ea, Nothing, AclPtr)
        MessageBox.Show("SetEntries = " & SetEntriesResult)
 
        Dim SecDesc As SECURITY_DESCRIPTOR
        Dim DecriptorInitResult As UInteger = InitializeSecurityDescriptor(SecDesc, SECURITY_DESCRIPTOR_REVISION)
        MessageBox.Show("InitSecurityDescriptor = " & DecriptorInitResult)
 
        Dim SetSecurityResult As UInteger = SetSecurityDescriptorDacl(SecDesc, True, AclPtr, False)
        MessageBox.Show("SetSecurityDescriptorDacl = " & SetSecurityResult)
 
        MessageBox.Show("Is Valid Descriptor = " & IsValidSecurityDesctiptor(SecDesc))
 
        Dim ShareInfo As New SHARE_INFO_502
        With ShareInfo
            .shi502_netname = "test"
            .shi502_type = STYPE_DISKTREE
            .shi502_remark = "Testing"
            .shi502_permissions = 0
            .shi502_max_uses = -1
            .shi502_current_uses = 0
            .shi502_path = "C:\TestingFolder"
            .shi502_passwd = Nothing
            .shi502_reserved = 0
            .shi502_security_descriptor = SecDesc
        End With
 
        'Dim Dacl As ACL = DirectCast(Marshal.PtrToStructure(SecDesc.Dacl, GetType(ACL)), ACL)
        'Dim ShareInfoSize As Integer = Marshal.SizeOf(ShareInfo)
        'Dim SharePtr As IntPtr = Marshal.AllocCoTaskMem(ShareInfoSize)
        'Marshal.StructureToPtr(ShareInfo, SharePtr, False)
 
        Dim ParameterError As Integer = 0
        Dim Result As String = NetShareAdd(Nothing, 502, ShareInfo, ParameterError).ToString
 
        MessageBox.Show("NetShareAdd result = " & Result & ", param error = " & ParameterError)
    End Sub
 
#End Region
 
 
#Region "Event Handlers"
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        CreateShare(Environment.UserDomainName & "\" & Environment.UserName)
    End Sub
 
#End Region

The problem definitely lies somewhere with the security descriptor because if I comment out this line then the code completes successfully and shares the folder (it just doesnt set the share permissions obviously) :

.shi502_security_descriptor = SecDesc