Marshal.ZeroFreeGlobalAllocAnsi(IntPtr) 메서드

정의

네임스페이스:

System.Runtime.InteropServices

어셈블리:

System.Runtime.InteropServices.dll

Source:

Marshal.cs

SecureStringToGlobalAllocAnsi(SecureString) 메서드를 사용하여 할당한 관리되지 않는 문자열 포인터를 해제합니다.

public:
 static void ZeroFreeGlobalAllocAnsi(IntPtr s);

public static void ZeroFreeGlobalAllocAnsi (IntPtr s);

static member ZeroFreeGlobalAllocAnsi : nativeint -> unit

Public Shared Sub ZeroFreeGlobalAllocAnsi (s As IntPtr)

매개 변수

s

IntPtr

nativeint

해제할 관리되지 않는 문자열의 주소입니다.

예제

다음 예제에서는 메서드를 SecureStringToGlobalAllocAnsi 사용하여 개체의 SecureString 내용을 관리되지 않는 메모리 블록으로 마샬링하고 암호 해독합니다. 그런 다음 메서드를 ZeroFreeGlobalAllocAnsi 사용하여 관리되지 않는 블록을 0으로 처리하고 삭제합니다.

using System;
using System.Runtime.InteropServices;
using System.Security;

class Example
{
    static void Main()
    {
        IntPtr unmanagedRef = IntPtr.Zero;

        // Ask the user for a password.
        Console.Write("Please enter your password: ");
        SecureString passWord = GetPassword();

        Console.WriteLine("Copying and decrypting the string to unmanaged memory...");
        // Copy the Secure string to unmanaged memory (and decrypt it).
        unmanagedRef = Marshal.SecureStringToGlobalAllocAnsi(passWord);
        passWord.Dispose();

        if (unmanagedRef != IntPtr.Zero) {
            Console.WriteLine("Zeroing out unmanaged memory...");
            Marshal.ZeroFreeGlobalAllocAnsi(unmanagedRef);
        }
        Console.WriteLine("Done.");
    }

    public static SecureString GetPassword()
    {
        SecureString password = new SecureString();

        // get the first character of the password
        ConsoleKeyInfo nextKey = Console.ReadKey(true);

        while (nextKey.Key != ConsoleKey.Enter) {
            if (nextKey.Key == ConsoleKey.Backspace) {
                if (password.Length > 0) {
                    password.RemoveAt(password.Length - 1);

                    // erase the last * as well
                    Console.Write(nextKey.KeyChar);
                    Console.Write(" ");
                    Console.Write(nextKey.KeyChar);
                }
            }
            else {
                password.AppendChar(nextKey.KeyChar);
                Console.Write("*");
            }

            nextKey = Console.ReadKey(true);
        }
        Console.WriteLine();

        // lock the password down
        password.MakeReadOnly();
        return password;
    }
}
// The example displays output like the following:
//       Please enter your password: ********
//       Copying and decrypting the string to unmanaged memory...
//       Zeroing out unmanaged memory...
//       Done.

Imports System.Runtime.InteropServices
Imports System.Security

Module Example
    Sub Main()
        Dim unmanagedRef As IntPtr

        ' Ask the user for a password.
        Console.Write("Please enter your password: ")
        Dim passWord As SecureString = GetPassword()

        Console.WriteLine("Copying and decrypting the string to unmanaged memory...")
        ' Copy the Secure string to unmanaged memory (and decrypt it).
        unmanagedRef = Marshal.SecureStringToGlobalAllocAnsi(passWord)
        passWord.Dispose()

        If unmanagedRef <> IntPtr.Zero Then
            Console.WriteLine("Zeroing out unmanaged memory...")
            Marshal.ZeroFreeGlobalAllocAnsi(unmanagedRef)
        End If
        Console.WriteLine("Done.")
    End Sub

    Function GetPassword() As SecureString
        Dim password As New SecureString()

        ' get the first character of the password
        Dim nextKey As ConsoleKeyInfo = Console.ReadKey(True)

        While nextKey.Key <> ConsoleKey.Enter
            If nextKey.Key = ConsoleKey.BackSpace Then
                If password.Length > 0 Then
                    password.RemoveAt(password.Length - 1)

                    ' Erase the last * as well.
                    Console.Write(nextKey.KeyChar)
                    Console.Write(" ")
                    Console.Write(nextKey.KeyChar)
                End If
            Else
                password.AppendChar(nextKey.KeyChar)
                Console.Write("*")
            End If

            nextKey = Console.ReadKey(True)
        End While
        Console.WriteLine()

        ' lock the password down
        password.MakeReadOnly()
        Return password
    End Function
End Module
' The example displays output like the following:
'       Please enter your password: ********
'       Copying and decrypting the string to unmanaged memory...
'       Zeroing out unmanaged memory...
'       Done.

설명

메서드는 ZeroFreeGlobalAllocAnsi 먼저 0을 해제한 다음 메서드를 사용하여 할당된 관리되지 않는 메모리를 SecureStringToGlobalAllocAnsi 해제합니다.