Marshal.SecureStringToGlobalAllocAnsi(SecureString) Méthode

Définition

Espace de noms:

System.Runtime.InteropServices

Assembly:

System.Runtime.InteropServices.dll

Source:

Marshal.cs

Important

Cette API n’est pas conforme CLS.

Copie le contenu d’un objet SecureString managé dans la mémoire non managée, avec conversion au format ANSI pendant la copie.

public:
 static IntPtr SecureStringToGlobalAllocAnsi(System::Security::SecureString ^ s);

public static IntPtr SecureStringToGlobalAllocAnsi (System.Security.SecureString s);

static member SecureStringToGlobalAllocAnsi : System.Security.SecureString -> nativeint

Public Shared Function SecureStringToGlobalAllocAnsi (s As SecureString) As IntPtr

Paramètres

s

SecureString

Objet managé à copier.

Retours

IntPtr

nativeint

Adresse (dans la mémoire non managée) où le paramètre s a été copié, ou 0 si un objet null a été fourni.

Exceptions

ArgumentNullException

Le paramètre s a la valeur null.

OutOfMemoryException

Il n’y a pas suffisamment de mémoire disponible.

Exemples

L’exemple suivant utilise la SecureStringToGlobalAllocAnsi méthode pour marshaler et déchiffrer le contenu d’un SecureString objet dans un bloc de mémoire non managée. Il utilise ensuite la ZeroFreeGlobalAllocAnsi méthode pour supprimer zéro et supprimer le bloc non managé.

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.

Remarques

La SecureStringToGlobalAllocAnsi méthode est utile pour le marshaling personnalisé ou lors du mélange de code managé et non managé. Étant donné que cette méthode alloue la mémoire non managée requise pour une chaîne, libérez toujours la mémoire en appelant la ZeroFreeGlobalAllocAnsi méthode.