/// <summary>
/// Creates or opens a shared memory view.
/// </summary>
/// <param name="sharedMemoryMapName"></param>
/// <param name="sharedMemorySize"></param>
/// <returns></returns>
public static new SharedMemoryMapView CreateOrOpen(string sharedMemoryMapName, ulong sharedMemorySize)
{
SharedMemorySafeHandle sharedMemoryHandle;
using (SecurityDescriptorSafePtr securityDescriptor = Security.CreateDefaultSecurityDescriptor())
{
var securityAttr = new Native.SECURITY_ATTRIBUTES
{
Length = (uint)Marshal.SizeOf <Native.SECURITY_ATTRIBUTES>(),
InheritHandle = false,
SecurityDescriptor = securityDescriptor.DangerousGetHandle(),
};
Utils.SplitULong(sharedMemorySize, out uint sharedMemorySizeHigh, out uint sharedMemorySizeLow);
sharedMemoryHandle = Native.CreateFileMapping(
Native.InvalidPointer,
ref securityAttr,
Native.FileMapProtection.PageReadWrite,
sharedMemorySizeHigh,
sharedMemorySizeLow,
sharedMemoryMapName);
}
if (sharedMemoryHandle.IsInvalid)
{
throw new FileNotFoundException(
$"Failed to CreateFileMapping {sharedMemoryMapName}",
innerException: new Win32Exception(Marshal.GetLastWin32Error()));
}
Security.VerifyHandleOwner(sharedMemoryHandle);
return(new SharedMemoryMapView(sharedMemoryHandle, sharedMemorySize));
}
private NamedEvent(string name)
{
using (SecurityDescriptorSafePtr securityDescriptor = Security.CreateDefaultSecurityDescriptor())
{
var securityAttr = new Native.SECURITY_ATTRIBUTES
{
Length = (uint)Marshal.SizeOf <Native.SECURITY_ATTRIBUTES>(),
InheritHandle = false,
SecurityDescriptor = securityDescriptor.DangerousGetHandle(),
};
eventHandle = Native.CreateEvent(
ref securityAttr,
manualReset: false,
initialState: false,
name);
if (eventHandle.IsInvalid)
{
throw new IOException(
$"Failed to create a NamedEvent {name}",
innerException: new Win32Exception(Marshal.GetLastWin32Error()));
}
Security.VerifyHandleOwner(eventHandle);
}
}
internal static extern int GetSecurityInfo(
[In] SafeHandle handle,
[In] SecurityObjectType objectType,
[In] SecurityInformation securityInformation,
[In] IntPtr sidOwner,
[In] IntPtr sidGroup,
[In] IntPtr dacl,
[In] IntPtr sacl,
[Out] out SecurityDescriptorSafePtr securityDescriptor);
/// <summary>
/// Check if handle has been created by authorized user.
/// </summary>
/// <param name="handle"></param>
/// <remarks>
/// Authorized users:
/// - built in administrators,
/// - current user.
/// </remarks>
internal static void VerifyHandleOwner(SafeHandle handle)
{
// Get the security descriptor for given handle.
//
int result = Native.GetSecurityInfo(
handle,
Native.SecurityObjectType.SecurityFileObject,
Native.SecurityInformation.OwnerSecurityInformation,
sidOwner: IntPtr.Zero,
sidGroup: IntPtr.Zero,
dacl: IntPtr.Zero,
sacl: IntPtr.Zero,
out SecurityDescriptorSafePtr handleSecurityDescriptor);
using SecurityDescriptorSafePtr scopedHandleSecurityDescriptor = handleSecurityDescriptor;
if (result != Native.ErrorSuccess)
{
throw new Win32Exception(result);
}
if (!Native.GetSecurityDescriptorOwner(handleSecurityDescriptor, out IntPtr handleOwnerSid, out bool ownerDefaulted1))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
// Allow access, if owner is local system.
//
if (Native.IsWellKnownSid(handleOwnerSid, Native.WellKnownSidType.WinLocalSystemSid))
{
return;
}
// Allow access, if owner is builtin administator.
//
if (Native.IsWellKnownSid(handleOwnerSid, Native.WellKnownSidType.WinBuiltinAdministratorsSid))
{
return;
}
// Allow acces, if current user is the owner.
//
using SecurityIdentifierSafePtr currentOwnerSecuryIdentifier = GetCurrentUserSid();
if (Native.EqualSid(currentOwnerSecuryIdentifier.DangerousGetHandle(), handleOwnerSid))
{
return;
}
throw new UnauthorizedAccessException();
}
internal static extern bool ConvertSecurityDescriptorToStringSecurityDescriptor(
[In] SecurityDescriptorSafePtr securityDescriptor,
[In] uint stringSDRevision,
[In] SecurityInformation securityInformation,
[Out] out string stringSecurityDescriptor,
[Out] out uint stringSecurityDescriptorLength);
internal static extern bool ConvertStringSecurityDescriptorToSecurityDescriptor(
[In] string stringSecurityDescriptor,
[In] uint stringSDRevision,
[Out] out SecurityDescriptorSafePtr securityDescriptor,
[Out] out int securityDescriptorSize);
internal static extern bool GetSecurityDescriptorOwner(
SecurityDescriptorSafePtr pSecurityDescriptor,
out IntPtr owner,
out bool ownerDefaulted);