更新 : 2007 年 11 月
すべての DES の実装の派生元となる DES (Data Encryption Standard) アルゴリズムの基本クラスを表します。
名前空間 :
System.Security.Cryptography アセンブリ :
mscorlib (mscorlib.dll 内)
<ComVisibleAttribute(True)> _
Public MustInherit Class DES _
Inherits SymmetricAlgorithm
[ComVisibleAttribute(true)]
public abstract class DES : SymmetricAlgorithm
[ComVisibleAttribute(true)]
public ref class DES abstract : public SymmetricAlgorithm
/** @attribute ComVisibleAttribute(true) */
public abstract class DES extends SymmetricAlgorithm
public abstract class DES extends SymmetricAlgorithm
このアルゴリズムは、64 ビットのキー長をサポートします。
指定したキー (Key) と初期化ベクタ (IV) で DESCryptoServiceProvider (DES の実装) を使用して、inName で指定したファイルを暗号化するメソッドを次のコード例に示します。このメソッドは、暗号化の結果を outName で指定したファイルに出力します。
Private Shared Sub EncryptData(inName As String, outName As String, _
desKey() As Byte, desIV() As Byte)
'Create the file streams to handle the input and output files.
Dim fin As New FileStream(inName, FileMode.Open, FileAccess.Read)
Dim fout As New FileStream(outName, FileMode.OpenOrCreate, _
FileAccess.Write)
fout.SetLength(0)
'Create variables to help with read and write.
Dim bin(4096) As Byte 'This is intermediate storage for the encryption.
Dim rdlen As Long = 0 'This is the total number of bytes written.
Dim totlen As Long = fin.Length 'Total length of the input file.
Dim len As Integer 'This is the number of bytes to be written at a time.
Dim des As New DESCryptoServiceProvider()
Dim encStream As New CryptoStream(fout, _
des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write)
Console.WriteLine("Encrypting...")
'Read from the input file, then encrypt and write to the output file.
While rdlen < totlen
len = fin.Read(bin, 0, 4096)
encStream.Write(bin, 0, len)
rdlen = Convert.ToInt32(rdlen + len / des.BlockSize * des.BlockSize)
Console.WriteLine("Processed {0} bytes, {1} bytes total", len, _
rdlen)
End While
encStream.Close()
End Sub
private static void EncryptData(String inName, String outName, byte[] desKey, byte[] desIV)
{
//Create the file streams to handle the input and output files.
FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
fout.SetLength(0);
//Create variables to help with read and write.
byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
long rdlen = 0; //This is the total number of bytes written.
long totlen = fin.Length; //This is the total length of the input file.
int len; //This is the number of bytes to be written at a time.
DES des = new DESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write);
Console.WriteLine("Encrypting...");
//Read from the input file, then encrypt and write to the output file.
while(rdlen < totlen)
{
len = fin.Read(bin, 0, 100);
encStream.Write(bin, 0, len);
rdlen = rdlen + len;
Console.WriteLine("{0} bytes processed", rdlen);
}
encStream.Close();
fout.Close();
fin.Close();
}
void EncryptData( String^ inName, String^ outName, array<Byte>^desKey, array<Byte>^desIV )
{
//Create the file streams to handle the input and output files.
FileStream^ fin = gcnew FileStream( inName,FileMode::Open,FileAccess::Read );
FileStream^ fout = gcnew FileStream( outName,FileMode::OpenOrCreate,FileAccess::Write );
fout->SetLength( 0 );
//Create variables to help with read and write.
array<Byte>^bin = gcnew array<Byte>(100);
long rdlen = 0; //This is the total number of bytes written.
long totlen = (long)fin->Length; //This is the total length of the input file.
int len; //This is the number of bytes to be written at a time.
DES^ des = gcnew DESCryptoServiceProvider;
CryptoStream^ encStream = gcnew CryptoStream( fout,des->CreateEncryptor( desKey, desIV ),CryptoStreamMode::Write );
Console::WriteLine( "Encrypting..." );
//Read from the input file, then encrypt and write to the output file.
while ( rdlen < totlen )
{
len = fin->Read( bin, 0, 100 );
encStream->Write( bin, 0, len );
rdlen = rdlen + len;
Console::WriteLine( "{0} bytes processed", rdlen );
}
encStream->Close();
fout->Close();
fin->Close();
}
private static void EncryptData(String inName,
String outName, ubyte desKey[], ubyte desIV[])
{
//Create the file streams to handle the input and output files.
FileStream fin = new FileStream(inName, FileMode.Open,
FileAccess.Read);
FileStream fout = new FileStream(outName, FileMode.OpenOrCreate,
FileAccess.Write);
fout.SetLength(0);
// Create variables to help with read and write.
ubyte bin[] = new ubyte[100]; // This is intermediate
// storage for the encryption.
long rdlen = 0; // This is the total
// number of bytes written.
long totlen = fin.get_Length(); // This is the total
// length of the input file.
int len; //This is the number of bytes to be written at a time.
DES des = new DESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout,
des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write);
Console.WriteLine("Encrypting...");
//Read from the input file, then encrypt and write to the output file.
while (rdlen < totlen) {
len = fin.Read(bin, 0, 100);
encStream.Write(bin, 0, len);
rdlen = rdlen + len;
Console.WriteLine("{0} bytes processed",
System.Convert.ToString(rdlen));
}
encStream.Close();
fout.Close();
fin.Close();
} //EncryptData
復号化も同じ方法で処理できます。ただし、その場合は CreateEncryptor の代わりに CreateDecryptor を使用します。復号化では、ファイルの暗号化に使用したものと同じキー (Key) と初期化ベクタ (IV) を使用する必要があります。
System..::.Object
System.Security.Cryptography..::.SymmetricAlgorithm
System.Security.Cryptography..::.DES
System.Security.Cryptography..::.DESCryptoServiceProvider
この型のすべてのパブリック static (Visual Basic では Shared) メンバは、スレッド セーフです。インスタンス メンバの場合は、スレッド セーフであるとは限りません。
Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC
.NET Framework および .NET Compact Framework では、各プラットフォームのすべてのバージョンはサポートしていません。サポートされているバージョンについては、「.NET Framework システム要件」を参照してください。
.NET Framework
サポート対象 : 3.5、3.0、2.0、1.1、1.0
.NET Compact Framework
サポート対象 : 3.5、2.0
参照
その他の技術情報