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

參考

定義

命名空間:: System.Security.Cryptography

組件:: System.Security.Cryptography.ProtectedData.dll

組件:: System.Security.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

解密指定之位元組陣列中的資料，並傳回包含已解密資料的位元組陣列。

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()

參數

encryptedData: Byte[]

含有使用 Protect(Byte[], Byte[], DataProtectionScope) 方法所加密的資料之位元組陣列。

optionalEntropy: Byte[]

進行資料加密所使用的選擇性額外位元組陣列，如果沒有使用額外位元組陣列則為 null。

scope: DataProtectionScope

其中一個列舉值，指定用來加密資料的資料保護範圍。

傳回

Byte[]

表示已解密資料的位元組陣列。

例外狀況

ArgumentNullException

encryptedData 參數為 null。

CryptographicException

解密失敗。

NotSupportedException

本作業系統不支援這個方法。

OutOfMemoryException

記憶體不足。

PlatformNotSupportedException

僅限 .NET Core 和 .NET 5+：只有 Windows作業系統支援對Unprotect方法的呼叫。

範例

下列程式碼範例示範如何使用資料保護。

#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

備註

這個方法可用來取消保護使用 Protect 方法加密的資料。 optionalEntropy如果在加密期間使用了參數，則必須提供參數來取消加密資料。

注意

如果您在模擬期間使用此方法，可能會收到下列錯誤：「金鑰不適用於指定狀態」。若要避免此錯誤，請在呼叫方法之前載入您想要模擬之使用者的設定檔。

適用於

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

定義

參數

傳回

例外狀況

範例

備註

適用於

其他資源