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

定义

命名空间:

System.Security.Cryptography

程序集:

System.Security.Cryptography.ProtectedData.dll

包:

System.Security.Cryptography.ProtectedData v9.0.0-rc.2.24473.5

Source:

ProtectedData.cs

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。

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);

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。

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。

scope

DataProtectionScope

指定用来加密数据的数据保护的范围的枚举值之一。

返回

Byte[]

表示已解密数据的字节数组。

例外

ArgumentNullException

encryptedData 参数为 null。

CryptographicException

解密失败。

NotSupportedException

该操作系统不支持此方法。

OutOfMemoryException

内存不足。

PlatformNotSupportedException

仅限 .NET Core 和 .NET 5+：仅 Windows 操作系统支持调用 Unprotect 方法。

示例

下面的代码示例演示如何使用数据保护。

#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

此方法可用于取消保护使用 Protect 方法加密的数据。 optionalEntropy如果在加密期间使用了 参数，则必须提供该参数来取消加密数据。

注意

如果在模拟期间使用此方法，可能会收到以下错误：“密钥在指定状态下使用无效。”若要防止此错误，请在调用 方法之前加载要模拟的用户的配置文件。