DESCryptoServiceProvider.CreateEncryptor メソッド

  • リファレンス

定義

名前空間:
System.Security.Cryptography
アセンブリ:
System.Security.Cryptography.Csp.dll
アセンブリ:
System.Security.Cryptography.dll
アセンブリ:
netstandard.dll
アセンブリ:
mscorlib.dll

対称暗号化オブジェクトを作成します。

オーバーロード

CreateEncryptor()

現在の Key プロパティおよび初期化ベクター (IV) を使用して、対称暗号化オブジェクトを作成します。
CreateEncryptor(Byte[], Byte[])

指定したキー (DES) および初期化ベクター (Key) を使用して、対称 IV (Data Encryption Standard) 暗号化オブジェクトを作成します。

CreateEncryptor()

現在の Key プロパティおよび初期化ベクター (IV) を使用して、対称暗号化オブジェクトを作成します。

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateEncryptor();
public override System.Security.Cryptography.ICryptoTransform CreateEncryptor ();
override this.CreateEncryptor : unit -> System.Security.Cryptography.ICryptoTransform
Public Overrides Function CreateEncryptor () As ICryptoTransform

戻り値

ICryptoTransform

対称暗号化オブジェクト。

注釈

現在 Key のプロパティが指定されている場合は null、メソッドが GenerateKey 呼び出され、新しいランダムが Key作成されます。 現在 IV のプロパティが指定されている場合は null、メソッドが GenerateIV 呼び出され、新しいランダムが IV作成されます。

同じシグネチャを CreateDecryptor 持つオーバーロードを使用して、このメソッドの結果を復号化します。

適用対象

CreateEncryptor(Byte[], Byte[])

指定したキー (DES) および初期化ベクター (Key) を使用して、対称 IV (Data Encryption Standard) 暗号化オブジェクトを作成します。

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateEncryptor(cli::array <System::Byte> ^ rgbKey, cli::array <System::Byte> ^ rgbIV);
public override System.Security.Cryptography.ICryptoTransform CreateEncryptor (byte[] rgbKey, byte[]? rgbIV);
public override System.Security.Cryptography.ICryptoTransform CreateEncryptor (byte[] rgbKey, byte[] rgbIV);
override this.CreateEncryptor : byte[] * byte[] -> System.Security.Cryptography.ICryptoTransform
Public Overrides Function CreateEncryptor (rgbKey As Byte(), rgbIV As Byte()) As ICryptoTransform

パラメーター

rgbKey
Byte[]

対称アルゴリズムに使用する共有キー。

rgbIV
Byte[]

対称アルゴリズムに使用する初期化ベクター。

戻り値

ICryptoTransform

対称 DES 暗号化オブジェクト。

例外

CryptographicException

Mode プロパティの値が OFB です。

または Mode プロパティの値が CFB であり、FeedbackSize プロパティの値が 8 ではありません。

または 無効なキー サイズが使用されました。

または アルゴリズムのキー サイズが使用できませんでした。

例

次のコード例は、オブジェクトを作成して使用して、ファイル内の DESCryptoServiceProvider データを暗号化および暗号化解除する方法を示しています。

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Text;
using namespace System::IO;
void EncryptTextToFile( String^ Data, String^ FileName, array<Byte>^Key, array<Byte>^IV )
{
   try
   {
      
      // Create or open the specified file.
      FileStream^ fStream = File::Open( FileName, FileMode::OpenOrCreate );
      
      // Create a CryptoStream using the FileStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( fStream,(gcnew DESCryptoServiceProvider)->CreateEncryptor( Key, IV ),CryptoStreamMode::Write );
      
      // Create a StreamWriter using the CryptoStream.
      StreamWriter^ sWriter = gcnew StreamWriter( cStream );
      
      // Write the data to the stream 
      // to encrypt it.
      sWriter->WriteLine( Data );
      
      // Close the streams and
      // close the file.
      sWriter->Close();
      cStream->Close();
      fStream->Close();
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
   }
   catch ( UnauthorizedAccessException^ e ) 
   {
      Console::WriteLine( "A file error occurred: {0}", e->Message );
   }

}

String^ DecryptTextFromFile( String^ FileName, array<Byte>^Key, array<Byte>^IV )
{
   try
   {
      
      // Create or open the specified file. 
      FileStream^ fStream = File::Open( FileName, FileMode::OpenOrCreate );
      
      // Create a CryptoStream using the FileStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( fStream,(gcnew DESCryptoServiceProvider)->CreateDecryptor( Key, IV ),CryptoStreamMode::Read );
      
      // Create a StreamReader using the CryptoStream.
      StreamReader^ sReader = gcnew StreamReader( cStream );
      
      // Read the data from the stream 
      // to decrypt it.
      String^ val = sReader->ReadLine();
      
      // Close the streams and
      // close the file.
      sReader->Close();
      cStream->Close();
      fStream->Close();
      
      // Return the string. 
      return val;
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }
   catch ( UnauthorizedAccessException^ e ) 
   {
      Console::WriteLine( "A file error occurred: {0}", e->Message );
      return nullptr;
   }

}

int main()
{
   try
   {
      
      // Create a new DESCryptoServiceProvider object
      // to generate a key and initialization vector (IV).
      DESCryptoServiceProvider^ DESalg = gcnew DESCryptoServiceProvider;
      
      // Create a string to encrypt.
      String^ sData = "Here is some data to encrypt.";
      String^ FileName = "CText.txt";
      
      // Encrypt text to a file using the file name, key, and IV.
      EncryptTextToFile( sData, FileName, DESalg->Key, DESalg->IV );
      
      // Decrypt the text from a file using the file name, key, and IV.
      String^ Final = DecryptTextFromFile( FileName, DESalg->Key, DESalg->IV );
      
      // Display the decrypted string to the console.
      Console::WriteLine( Final );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class DESCSPSample
{

    static void Main()
    {
        try
        {
            // Create a new DESCryptoServiceProvider object
            // to generate a key and initialization vector (IV).
            DESCryptoServiceProvider DESalg = new DESCryptoServiceProvider();

            // Create a string to encrypt.
            string sData = "Here is some data to encrypt.";
            string FileName = "CText.txt";

            // Encrypt text to a file using the file name, key, and IV.
            EncryptTextToFile(sData, FileName, DESalg.Key, DESalg.IV);

            // Decrypt the text from a file using the file name, key, and IV.
            string Final = DecryptTextFromFile(FileName, DESalg.Key, DESalg.IV);

            // Display the decrypted string to the console.
            Console.WriteLine(Final);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    public static void EncryptTextToFile(String Data, String FileName, byte[] Key, byte[] IV)
    {
        try
        {
            // Create or open the specified file.
            FileStream fStream = File.Open(FileName,FileMode.OpenOrCreate);

            // Create a CryptoStream using the FileStream
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(fStream,
                new DESCryptoServiceProvider().CreateEncryptor(Key,IV),
                CryptoStreamMode.Write);

            // Create a StreamWriter using the CryptoStream.
            StreamWriter sWriter = new StreamWriter(cStream);

            // Write the data to the stream
            // to encrypt it.
            sWriter.WriteLine(Data);

            // Close the streams and
            // close the file.
            sWriter.Close();
            cStream.Close();
            fStream.Close();
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
        }
        catch(UnauthorizedAccessException  e)
        {
            Console.WriteLine("A file error occurred: {0}", e.Message);
        }
    }

    public static string DecryptTextFromFile(String FileName, byte[] Key, byte[] IV)
    {
        try
        {
            // Create or open the specified file.
            FileStream fStream = File.Open(FileName, FileMode.OpenOrCreate);

            // Create a CryptoStream using the FileStream
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(fStream,
                new DESCryptoServiceProvider().CreateDecryptor(Key,IV),
                CryptoStreamMode.Read);

            // Create a StreamReader using the CryptoStream.
            StreamReader sReader = new StreamReader(cStream);

            // Read the data from the stream
            // to decrypt it.
            string val = sReader.ReadLine();

            // Close the streams and
            // close the file.
            sReader.Close();
            cStream.Close();
            fStream.Close();

            // Return the string.
            return val;
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }
        catch(UnauthorizedAccessException  e)
        {
            Console.WriteLine("A file error occurred: {0}", e.Message);
            return null;
        }
    }
}

Imports System.Security.Cryptography
Imports System.Text
Imports System.IO

Module DESCSPSample

    Sub Main()
        Try
            ' Create a new DESCryptoServiceProvider object
            ' to generate a key and initialization vector (IV).
            Dim DESalg As New DESCryptoServiceProvider

            ' Create a string to encrypt.
            Dim sData As String = "Here is some data to encrypt."
            Dim FileName As String = "CText.txt"

            ' Encrypt text to a file using the file name, key, and IV.
            EncryptTextToFile(sData, FileName, DESalg.Key, DESalg.IV)

            ' Decrypt the text from a file using the file name, key, and IV.
            Dim Final As String = DecryptTextFromFile(FileName, DESalg.Key, DESalg.IV)

            ' Display the decrypted string to the console.
            Console.WriteLine(Final)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    End Sub


    Sub EncryptTextToFile(ByVal Data As String, ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte)
        Try
            ' Create or open the specified file.
            Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)

            ' Create a CryptoStream using the FileStream 
            ' and the passed key and initialization vector (IV).
            Dim cStream As New CryptoStream(fStream, _
                                            New DESCryptoServiceProvider().CreateEncryptor(Key, IV), _
                                            CryptoStreamMode.Write)

            ' Create a StreamWriter using the CryptoStream.
            Dim sWriter As New StreamWriter(cStream)

            ' Write the data to the stream 
            ' to encrypt it.
            sWriter.WriteLine(Data)

            ' Close the streams and
            ' close the file.
            sWriter.Close()
            cStream.Close()
            fStream.Close()
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
        Catch e As UnauthorizedAccessException
            Console.WriteLine("A file error occurred: {0}", e.Message)
        End Try
    End Sub


    Function DecryptTextFromFile(ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte) As String
        Try
            ' Create or open the specified file. 
            Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)

            ' Create a CryptoStream using the FileStream 
            ' and the passed key and initialization vector (IV).
            Dim cStream As New CryptoStream(fStream, _
                                            New DESCryptoServiceProvider().CreateDecryptor(Key, IV), _
                                            CryptoStreamMode.Read)

            ' Create a StreamReader using the CryptoStream.
            Dim sReader As New StreamReader(cStream)

            ' Read the data from the stream 
            ' to decrypt it.
            Dim val As String = sReader.ReadLine()

            ' Close the streams and
            ' close the file.
            sReader.Close()
            cStream.Close()
            fStream.Close()

            ' Return the string. 
            Return val
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing
        Catch e As UnauthorizedAccessException
            Console.WriteLine("A file error occurred: {0}", e.Message)
            Return Nothing
        End Try
    End Function
End Module

次のコード例は、オブジェクトを作成して使用して、メモリ内の DESCryptoServiceProvider データを暗号化および暗号化解除する方法を示しています。

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Text;
using namespace System::IO;
array<Byte>^ EncryptTextToMemory( String^ Data, array<Byte>^Key, array<Byte>^IV )
{
   try
   {
      
      // Create a MemoryStream.
      MemoryStream^ mStream = gcnew MemoryStream;
      
      // Create a CryptoStream using the MemoryStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( mStream,(gcnew DESCryptoServiceProvider)->CreateEncryptor( Key, IV ),CryptoStreamMode::Write );
      
      // Convert the passed string to a byte array.
      array<Byte>^toEncrypt = (gcnew ASCIIEncoding)->GetBytes( Data );
      
      // Write the byte array to the crypto stream and flush it.
      cStream->Write( toEncrypt, 0, toEncrypt->Length );
      cStream->FlushFinalBlock();
      
      // Get an array of bytes from the 
      // MemoryStream that holds the 
      // encrypted data.
      array<Byte>^ret = mStream->ToArray();
      
      // Close the streams.
      cStream->Close();
      mStream->Close();
      
      // Return the encrypted buffer.
      return ret;
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }

}

String^ DecryptTextFromMemory( array<Byte>^Data, array<Byte>^Key, array<Byte>^IV )
{
   try
   {
      
      // Create a new MemoryStream using the passed 
      // array of encrypted data.
      MemoryStream^ msDecrypt = gcnew MemoryStream( Data );
      
      // Create a CryptoStream using the MemoryStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ csDecrypt = gcnew CryptoStream( msDecrypt,(gcnew DESCryptoServiceProvider)->CreateDecryptor( Key, IV ),CryptoStreamMode::Read );
      
      // Create buffer to hold the decrypted data.
      array<Byte>^fromEncrypt = gcnew array<Byte>(Data->Length);
      
      // Read the decrypted data out of the crypto stream
      // and place it into the temporary buffer.
      csDecrypt->Read( fromEncrypt, 0, fromEncrypt->Length );
      
      //Convert the buffer into a string and return it.
      return (gcnew ASCIIEncoding)->GetString( fromEncrypt );
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }

}

int main()
{
   try
   {
      
      // Create a new DESCryptoServiceProvider object
      // to generate a key and initialization vector (IV).
      DESCryptoServiceProvider^ DESalg = gcnew DESCryptoServiceProvider;
      
      // Create a string to encrypt.
      String^ sData = "Here is some data to encrypt.";
      
      // Encrypt the string to an in-memory buffer.
      array<Byte>^Data = EncryptTextToMemory( sData, DESalg->Key, DESalg->IV );
      
      // Decrypt the buffer back to a string.
      String^ Final = DecryptTextFromMemory( Data, DESalg->Key, DESalg->IV );
      
      // Display the decrypted string to the console.
      Console::WriteLine( Final );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class DESCSPSample
{
    static void Main()
    {
        try
        {
            // Create a new DESCryptoServiceProvider object
            // to generate a key and initialization vector (IV).
            DESCryptoServiceProvider DESalg = new DESCryptoServiceProvider();

            // Create a string to encrypt.
            string sData = "Here is some data to encrypt.";

            // Encrypt the string to an in-memory buffer.
            byte[] Data = EncryptTextToMemory(sData, DESalg.Key, DESalg.IV);

            // Decrypt the buffer back to a string.
            string Final = DecryptTextFromMemory(Data, DESalg.Key, DESalg.IV);

            // Display the decrypted string to the console.
            Console.WriteLine(Final);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    public static byte[] EncryptTextToMemory(string Data,  byte[] Key, byte[] IV)
    {
        try
        {
            // Create a MemoryStream.
            MemoryStream mStream = new MemoryStream();

            // Create a CryptoStream using the MemoryStream
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(mStream,
                new DESCryptoServiceProvider().CreateEncryptor(Key, IV),
                CryptoStreamMode.Write);

            // Convert the passed string to a byte array.
            byte[] toEncrypt = new ASCIIEncoding().GetBytes(Data);

            // Write the byte array to the crypto stream and flush it.
            cStream.Write(toEncrypt, 0, toEncrypt.Length);
            cStream.FlushFinalBlock();

            // Get an array of bytes from the
            // MemoryStream that holds the
            // encrypted data.
            byte[] ret = mStream.ToArray();

            // Close the streams.
            cStream.Close();
            mStream.Close();

            // Return the encrypted buffer.
            return ret;
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }
    }

    public static string DecryptTextFromMemory(byte[] Data,  byte[] Key, byte[] IV)
    {
        try
        {
            // Create a new MemoryStream using the passed
            // array of encrypted data.
            MemoryStream msDecrypt = new MemoryStream(Data);

            // Create a CryptoStream using the MemoryStream
            // and the passed key and initialization vector (IV).
            CryptoStream csDecrypt = new CryptoStream(msDecrypt,
                new DESCryptoServiceProvider().CreateDecryptor(Key, IV),
                CryptoStreamMode.Read);

            // Create buffer to hold the decrypted data.
            byte[] fromEncrypt = new byte[Data.Length];

            // Read the decrypted data out of the crypto stream
            // and place it into the temporary buffer.
            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);

            //Convert the buffer into a string and return it.
            return new ASCIIEncoding().GetString(fromEncrypt);
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }
    }
}

Imports System.Security.Cryptography
Imports System.Text
Imports System.IO

Module DESCSPSample

    Sub Main()
        Try
            ' Create a new DESCryptoServiceProvider object
            ' to generate a key and initialization vector (IV).
            Dim DESalg As New DESCryptoServiceProvider

            ' Create a string to encrypt.
            Dim sData As String = "Here is some data to encrypt."

            ' Encrypt the string to an in-memory buffer.
            Dim Data As Byte() = EncryptTextToMemory(sData, DESalg.Key, DESalg.IV)

            ' Decrypt the buffer back to a string.
            Dim Final As String = DecryptTextFromMemory(Data, DESalg.Key, DESalg.IV)

            ' Display the decrypted string to the console.
            Console.WriteLine(Final)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    End Sub


    Function EncryptTextToMemory(ByVal Data As String, ByVal Key() As Byte, ByVal IV() As Byte) As Byte()
        Try
            ' Create a MemoryStream.
            Dim mStream As New MemoryStream

            ' Create a CryptoStream using the MemoryStream 
            ' and the passed key and initialization vector (IV).
            Dim cStream As New CryptoStream(mStream, _
                                            New DESCryptoServiceProvider().CreateEncryptor(Key, IV), _
                                            CryptoStreamMode.Write)

            ' Convert the passed string to a byte array.
            Dim toEncrypt As Byte() = New ASCIIEncoding().GetBytes(Data)

            ' Write the byte array to the crypto stream and flush it.
            cStream.Write(toEncrypt, 0, toEncrypt.Length)
            cStream.FlushFinalBlock()

            ' Get an array of bytes from the 
            ' MemoryStream that holds the 
            ' encrypted data.
            Dim ret As Byte() = mStream.ToArray()

            ' Close the streams.
            cStream.Close()
            mStream.Close()

            ' Return the encrypted buffer.
            Return ret
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing
        End Try
    End Function


    Function DecryptTextFromMemory(ByVal Data() As Byte, ByVal Key() As Byte, ByVal IV() As Byte) As String
        Try
            ' Create a new MemoryStream using the passed 
            ' array of encrypted data.
            Dim msDecrypt As New MemoryStream(Data)

            ' Create a CryptoStream using the MemoryStream 
            ' and the passed key and initialization vector (IV).
            Dim csDecrypt As New CryptoStream(msDecrypt, _
                                              New DESCryptoServiceProvider().CreateDecryptor(Key, IV), _
                                              CryptoStreamMode.Read)

            ' Create buffer to hold the decrypted data.
            Dim fromEncrypt(Data.Length - 1) As Byte

            ' Read the decrypted data out of the crypto stream
            ' and place it into the temporary buffer.
            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length)

            'Convert the buffer into a string and return it.
            Return New ASCIIEncoding().GetString(fromEncrypt)
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing
        End Try
    End Function
End Module

注釈

同じパラメーターを CreateDecryptor 持つオーバーロードを使用して、このメソッドの結果を復号化します。

こちらもご覧ください

適用対象