Marshal.SecureStringToCoTaskMemUnicode(SecureString) Método

Definición

Importante

Esta API no es conforme a CLS.

Copia el contenido de un objeto SecureString administrado en un bloque de memoria asignado desde el asignador de tareas COM no administrado.Copies the contents of a managed SecureString object to a block of memory allocated from the unmanaged COM task allocator.

public:
 static IntPtr SecureStringToCoTaskMemUnicode(System::Security::SecureString ^ s);
[System.CLSCompliant(false)]
[System.Security.SecurityCritical]
public static IntPtr SecureStringToCoTaskMemUnicode (System.Security.SecureString s);
static member SecureStringToCoTaskMemUnicode : System.Security.SecureString -> nativeint
Public Shared Function SecureStringToCoTaskMemUnicode (s As SecureString) As IntPtr

Parámetros

s
SecureString

Objeto administrado que se va a copiar.The managed object to copy.

Devoluciones

Dirección, en memoria no administrada, donde se copió el parámetro s o 0 si se suministró un objeto null.The address, in unmanaged memory, where the s parameter was copied to, or 0 if a null object was supplied.

Atributos

Excepciones

El parámetro s es null.The s parameter is null.

El equipo actual no está ejecutando Windows 2000 Service Pack 3 o una versión posterior.The current computer is not running Windows 2000 Service Pack 3 or later.

No hay suficiente memoria disponible.There is insufficient memory available.

Ejemplos

En el ejemplo siguiente se usa el método SecureStringToCoTaskMemUnicode para calcular las referencias y descifrar el contenido de un objeto SecureString en un bloque de memoria no administrada.The following example uses the SecureStringToCoTaskMemUnicode method to marshal and decrypt the contents of a SecureString object to a block of unmanaged memory. A continuación, usa el método ZeroFreeCoTaskMemUnicode para desechar el bloque no administrado.It then uses the ZeroFreeCoTaskMemUnicode method to zero out and dispose the unmanaged block.

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.SecureStringToCoTaskMemUnicode(passWord);
        passWord.Dispose();
        
        if (unmanagedRef != IntPtr.Zero) {
            Console.WriteLine("Zeroing out unmanaged memory...");
            Marshal.ZeroFreeCoTaskMemUnicode(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
    Public 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.SecureStringToCoTaskMemUnicode(passWord)
        passWord.Dispose()

        If unmanagedRef <> IntPtr.Size Then
            Console.WriteLine("Zeroing out unmanaged memory...")
            Marshal.ZeroFreeCoTaskMemUnicode(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.

Comentarios

El método SecureStringToCoTaskMemUnicode es útil para el cálculo de referencias personalizado o al combinar código administrado y no administrado.The SecureStringToCoTaskMemUnicode method is useful for custom marshaling or when mixing managed and unmanaged code. Dado que este método asigna la memoria no administrada necesaria para una cadena, libere siempre la memoria llamando al método ZeroFreeCoTaskMemUnicode.Because this method allocates the unmanaged memory required for a string, always free the memory by calling the ZeroFreeCoTaskMemUnicode method. Los caracteres de la cadena se copian como caracteres Unicode.The characters of the string are copied as Unicode characters.

Notas a los autores de las llamadas

Este método solo se admite en equipos que ejecutan Windows 2000 Service Pack 3 o posterior.This method is supported only on computers running Windows 2000 Service Pack 3 or later.

Seguridad

SecurityCriticalAttribute
Requiere plena confianza para el llamador inmediato.requires full trust for the immediate caller. Este miembro no puede ser utilizado por código transparente o de confianza parcial.This member cannot be used by partially trusted or transparent code.

Se aplica a