C# 3DES加密解密

///
/// DES3加密解密
///
public class Des3
{
#region CBC模式**

///
/// DES3 CBC模式加密
///
/// 密钥
/// IV
/// 明文的byte数组
/// 密文的byte数组
public static byte[] Des3EncodeCBC( byte[] key, byte[] iv, byte[] data )
{
//复制于MSDN

try
{
// Create a MemoryStream.
MemoryStream mStream = new MemoryStream();

TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
tdsp.Mode = CipherMode.CBC;             //默认值
tdsp.Padding = PaddingMode.PKCS7;       //默认值

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

// Write the byte array to the crypto stream and flush it.
cStream.Write( data, 0, data.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;
}
}

///
/// DES3 CBC模式解密
///
/// 密钥
/// IV
/// 密文的byte数组
/// 明文的byte数组
public static byte[] Des3DecodeCBC( byte[] key, byte[] iv, byte[] data )
{
try
{
// Create a new MemoryStream using the passed
// array of encrypted data.
MemoryStream msDecrypt = new MemoryStream( data );

TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
tdsp.Mode = CipherMode.CBC;
tdsp.Padding = PaddingMode.PKCS7;

// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
CryptoStream csDecrypt = new CryptoStream( msDecrypt,
tdsp.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 fromEncrypt;
}
catch ( CryptographicException e )
{
Console.WriteLine( "A Cryptographic error occurred: {0}", e.Message );
return null;
}
}

#endregion

#region ECB模式

///
/// DES3 ECB模式加密
///
/// 密钥
/// IV(当模式为ECB时，IV无用)
/// 明文的byte数组
/// 密文的byte数组
public static byte[] Des3EncodeECB( byte[] key, byte[] iv, byte[] data )
{
try
{
// Create a MemoryStream.
MemoryStream mStream = new MemoryStream();

TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
tdsp.Mode = CipherMode.ECB;
tdsp.Padding = PaddingMode.PKCS7;
// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
CryptoStream cStream = new CryptoStream( mStr
4000
eam,
tdsp.CreateEncryptor( key, iv ),
CryptoStreamMode.Write );

// Write the byte array to the crypto stream and flush it.
cStream.Write( data, 0, data.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;
}

}

///
/// DES3 ECB模式解密
///
/// 密钥
/// IV(当模式为ECB时，IV无用)
/// 密文的byte数组
/// 明文的byte数组
public static byte[] Des3DecodeECB( byte[] key, byte[] iv, byte[] data )
{
try
{
// Create a new MemoryStream using the passed
// array of encrypted data.
MemoryStream msDecrypt = new MemoryStream( data );

TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider();
tdsp.Mode = CipherMode.ECB;
tdsp.Padding = PaddingMode.PKCS7;

// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
CryptoStream csDecrypt = new CryptoStream( msDecrypt,
tdsp.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 fromEncrypt;
}
catch ( CryptographicException e )
{
Console.WriteLine( "A Cryptographic error occurred: {0}", e.Message );
return null;
}
}

#endregion

///
/// 类测试
///
public static void Test()
{
System.Text.Encoding utf8 = System.Text.Encoding.UTF8;

//key为abcdefghijklmnopqrstuvwx的Base64编码
//注意:key的值必须是16/24位
byte[] key = Convert.FromBase64String( "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4" );
byte[] iv = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };      //当模式为ECB时，IV无用
byte[] data = utf8.GetBytes( "中国ABCabc123" );

System.Console.WriteLine( "ECB模式:" );
byte[] str1 = Des3.Des3EncodeECB( key, iv, data );
byte[] str2 = Des3.Des3DecodeECB( key, iv, str1 );
System.Console.WriteLine( Convert.ToBase64String( str1 ) );
System.Console.WriteLine( System.Text.Encoding.UTF8.GetString( str2 ) );

System.Console.WriteLine();

System.Console.WriteLine( "CBC模式:" );
byte[] str3 = Des3.Des3EncodeCBC( key, iv, data );
byte[] str4 = Des3.Des3DecodeCBC( key, iv, str3 );
System.Console.WriteLine( Convert.ToBase64String( str3 ) );
System.Console.WriteLine( utf8.GetString( str4 ) );

System.Console.WriteLine();

}

}