ProtectedData.Unprotect(Byte[], Byte[], DataProtectionScope) 方法

定义

在指定的字节数组中解密数据,并返回包含已解密数据的字节数组。Decrypts the data in a specified byte array and returns a byte array that contains the decrypted data.

public:
 static cli::array <System::Byte> ^ Unprotect(cli::array <System::Byte> ^ encryptedData, cli::array <System::Byte> ^ optionalEntropy, System::Security::Cryptography::DataProtectionScope scope);
public static byte[] Unprotect (byte[] encryptedData, byte[] optionalEntropy, System.Security.Cryptography.DataProtectionScope scope);
public static byte[] Unprotect (byte[] encryptedData, byte[]? optionalEntropy, System.Security.Cryptography.DataProtectionScope scope);
static member Unprotect : byte[] * byte[] * System.Security.Cryptography.DataProtectionScope -> byte[]
Public Shared Function Unprotect (encryptedData As Byte(), optionalEntropy As Byte(), scope As DataProtectionScope) As Byte()

参数

encryptedData
Byte[]

一个字节数组,包含用 Protect(Byte[], Byte[], DataProtectionScope) 方法加密的数据。A byte array containing data encrypted using the Protect(Byte[], Byte[], DataProtectionScope) method.

optionalEntropy
Byte[]

用于加密数据,或 null 的可选的额外的字节数组,如果不使用额外的字节数组。An optional additional byte array that was used to encrypt the data, or null if the additional byte array was not used.

scope
DataProtectionScope

指定用来加密数据的数据保护的范围的枚举值之一。One of the enumeration values that specifies the scope of data protection that was used to encrypt the data.

返回

Byte[]

表示已解密数据的字节数组。A byte array representing the decrypted data.

例外

encryptedData 参数为 nullThe encryptedData parameter is null.

解密失败。The decryption failed.

该操作系统不支持此方法。The operating system does not support this method.

内存不足。Out of memory.

仅限 .NET Core:仅 Windows 操作系统支持调用 Unprotect 方法。.NET Core only: Calls to the Unprotect method are supported on Windows operating systems only.

示例

下面的代码示例演示如何使用数据保护。The following code example shows how to use data protection.

#using <System.Security.dll>

using namespace System;
using namespace System::Security::Cryptography;

public ref class DataProtectionSample
{
private:

   // Create byte array for additional entropy when using Protect method.
   static array<Byte>^s_additionalEntropy = {9,8,7,6,5};

public:
   static void Main()
   {
      
      // Create a simple byte array containing data to be encrypted.
      array<Byte>^secret = {0,1,2,3,4,1,2,3,4};
      
      //Encrypt the data.
      array<Byte>^encryptedSecret = Protect( secret );
      Console::WriteLine( "The encrypted byte array is:" );
      PrintValues( encryptedSecret );
      
      // Decrypt the data and store in a byte array.
      array<Byte>^originalData = Unprotect( encryptedSecret );
      Console::WriteLine( "{0}The original data is:", Environment::NewLine );
      PrintValues( originalData );
   }

   static array<Byte>^ Protect( array<Byte>^data )
   {
      try
      {
         
         // Encrypt the data using DataProtectionScope.CurrentUser. The result can be decrypted
         //  only by the same current user.
         return ProtectedData::Protect( data, s_additionalEntropy, DataProtectionScope::CurrentUser );
      }
      catch ( CryptographicException^ e ) 
      {
         Console::WriteLine( "Data was not encrypted. An error occurred." );
         Console::WriteLine( e );
         return nullptr;
      }
   }

   static array<Byte>^ Unprotect( array<Byte>^data )
   {
      try
      {
         
         //Decrypt the data using DataProtectionScope.CurrentUser.
         return ProtectedData::Unprotect( data, s_additionalEntropy, DataProtectionScope::CurrentUser );
      }
      catch ( CryptographicException^ e ) 
      {
         Console::WriteLine( "Data was not decrypted. An error occurred." );
         Console::WriteLine( e );
         return nullptr;
      }
   }

   static void PrintValues( array<Byte>^myArr )
   {
      System::Collections::IEnumerator^ myEnum = myArr->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         Byte i = safe_cast<Byte>(myEnum->Current);
         Console::Write( "\t{0}", i );
      }

      Console::WriteLine();
   }
};

int main()
{
   DataProtectionSample::Main();
}
using System;
using System.Security.Cryptography;

public class DataProtectionSample
{
    // Create byte array for additional entropy when using Protect method.
    static byte [] s_additionalEntropy = { 9, 8, 7, 6, 5 };

    public static void Main()
    {
        // Create a simple byte array containing data to be encrypted.
        byte [] secret = { 0, 1, 2, 3, 4, 1, 2, 3, 4 };

        //Encrypt the data.
        byte [] encryptedSecret = Protect( secret );
        Console.WriteLine("The encrypted byte array is:");
        PrintValues(encryptedSecret);

        // Decrypt the data and store in a byte array.
        byte [] originalData = Unprotect( encryptedSecret );
        Console.WriteLine("{0}The original data is:", Environment.NewLine);
        PrintValues(originalData);
    }

    public static byte [] Protect( byte [] data )
    {
        try
        {
            // Encrypt the data using DataProtectionScope.CurrentUser. The result can be decrypted
            // only by the same current user.
            return ProtectedData.Protect( data, s_additionalEntropy, DataProtectionScope.CurrentUser );
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("Data was not encrypted. An error occurred.");
            Console.WriteLine(e.ToString());
            return null;
        }
    }

    public static byte [] Unprotect( byte [] data )
    {
        try
        {
            //Decrypt the data using DataProtectionScope.CurrentUser.
            return ProtectedData.Unprotect( data, s_additionalEntropy, DataProtectionScope.CurrentUser );
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("Data was not decrypted. An error occurred.");
            Console.WriteLine(e.ToString());
            return null;
        }
    }

    public static void PrintValues( Byte[] myArr )
    {
        foreach ( Byte i in myArr )
        {
            Console.Write( "\t{0}", i );
        }
        Console.WriteLine();
    }
}
Imports System.Security.Cryptography



Public Class DataProtectionSample
    ' Create byte array for additional entropy when using Protect method.
    Private Shared s_additionalEntropy As Byte() = {9, 8, 7, 6, 5}


    Public Shared Sub Main()
        ' Create a simple byte array containing data to be encrypted.
        Dim secret As Byte() = {0, 1, 2, 3, 4, 1, 2, 3, 4}

        'Encrypt the data.
        Dim encryptedSecret As Byte() = Protect(secret)
        Console.WriteLine("The encrypted byte array is:")
        PrintValues(encryptedSecret)

        ' Decrypt the data and store in a byte array.
        Dim originalData As Byte() = Unprotect(encryptedSecret)
        Console.WriteLine("{0}The original data is:", Environment.NewLine)
        PrintValues(originalData)

    End Sub


    Public Shared Function Protect(ByVal data() As Byte) As Byte()
        Try
            ' Encrypt the data using DataProtectionScope.CurrentUser. The result can be decrypted
            '  only by the same current user.
            Return ProtectedData.Protect(data, s_additionalEntropy, DataProtectionScope.CurrentUser)
        Catch e As CryptographicException
            Console.WriteLine("Data was not encrypted. An error occurred.")
            Console.WriteLine(e.ToString())
            Return Nothing
        End Try

    End Function


    Public Shared Function Unprotect(ByVal data() As Byte) As Byte()
        Try
            'Decrypt the data using DataProtectionScope.CurrentUser.
            Return ProtectedData.Unprotect(data, s_additionalEntropy, DataProtectionScope.CurrentUser)
        Catch e As CryptographicException
            Console.WriteLine("Data was not decrypted. An error occurred.")
            Console.WriteLine(e.ToString())
            Return Nothing
        End Try

    End Function


    Public Shared Sub PrintValues(ByVal myArr() As [Byte])
        Dim i As [Byte]
        For Each i In myArr
            Console.Write(vbTab + "{0}", i)
        Next i
        Console.WriteLine()

    End Sub
End Class

注解

此方法可用于取消对使用方法加密的数据的保护 ProtectThis method can be used to unprotect data that was encrypted using the Protect method. 如果在 optionalEntropy 加密过程中使用了参数,则必须提供它来解密数据。If the optionalEntropy parameter was used during encryption, it must be supplied to unencrypt the data.

备注

如果在模拟过程中使用此方法,则可能会收到以下错误: "键在指定状态下不可用。"If you use this method during impersonation, you may receive the following error: "Key not valid for use in specified state." 若要避免此错误,请在调用方法之前加载要模拟的用户的配置文件。To prevent this error, load the profile of the user you want to impersonate before calling the method.

适用于