internal class EncryptTransform
{
//private const int c_MaxLengthOf_IV_DES = 4;
//private const int c_MaxLengthOf_IV_RC2 = 4;
//private const int c_MaxLengthOf_IV_RIJNDAEL = 8;
//private const int c_MaxLengthOf_IV_TRIPLEDES = 4;
//private const int c_MaxLengthOf_Key_DES = 4;
//private const int c_MaxLengthOf_Key_RC2 = 4;
//private const int c_MaxLengthOf_Key_RIJNDAEL_1 = 8;
//private const int c_MaxLengthOf_Key_RIJNDAEL_2 = 12;
//private const int c_MaxLengthOf_Key_TRIPLEDES_1 = 8;
//private const int c_MaxLengthOf_Key_TRIPLEDES_2 = 12; private byte[] m_Key = null; /// <summary>
/// 获取或设置加密解密过程中使用的明文密码
/// </summary>
public byte[] Key
{
get { return m_Key; }
set { m_Key = value; }
} private byte[] m_initVec = null;
/// <summary>
/// 获取或设置加密解密过程中使用的初始化向量
/// </summary>
public byte[] InitVec
{
get { return m_initVec; }
set { m_initVec = value; }
} public EncryptTransform(byte[] key, byte[] initVector)
{
this.m_Key = key;
this.m_initVec = initVector;
}
/// <summary>
/// 根据提供的枚举信息,获得需要使用的解密算法的接口
/// </summary>
/// <param name="algorithm"></param>
/// <returns></returns>
internal ICryptoTransform GetDecryptoServiceProvider(EncryptionAlgorithm algorithm)
{
switch (algorithm)
{
case EncryptionAlgorithm.Des:
{
DES des = new DESCryptoServiceProvider();
des.Mode = CipherMode.CBC;
if (this.m_Key != null)
{
des.Key = m_Key;
}
if (m_initVec != null)
{
des.IV = m_initVec;
}
return des.CreateDecryptor();
}
case EncryptionAlgorithm.Rc2:
{
RC2 rc = new RC2CryptoServiceProvider();
rc.Mode = CipherMode.CBC;
return rc.CreateDecryptor(m_Key, m_initVec);
}
case EncryptionAlgorithm.Rijndael:
{
Rijndael rijndael = new RijndaelManaged();
rijndael.Mode = CipherMode.CBC;
return rijndael.CreateDecryptor(m_Key, m_initVec);
}
case EncryptionAlgorithm.TripleDes:
{
TripleDES edes = new TripleDESCryptoServiceProvider();
edes.Mode = CipherMode.CBC;
return edes.CreateDecryptor(m_Key, m_initVec);
}
}
throw new CryptographicException("Algorithm ID '" + algorithm + "' not supported.");
} /// <summary>
/// 根据提供的枚举信息,获得需要使用的加密算法的接口
/// </summary>
/// <param name="algorithm">算法枚举</param>
/// <returns></returns>
internal ICryptoTransform GetEncryptoServiceProvider(EncryptionAlgorithm algorithm)
{ switch (algorithm)
{
case EncryptionAlgorithm.Des:
{
DES des = new DESCryptoServiceProvider();
des.Mode = CipherMode.CBC;
if (null != m_Key)
{
des.Key = m_Key;
}
else
{
m_Key = des.Key;
}
if (null != m_initVec)
{
des.IV = m_initVec;
}
else
{
m_initVec = des.IV;
}
return des.CreateEncryptor();
} case EncryptionAlgorithm.Rc2:
{
RC2 rc = new RC2CryptoServiceProvider();
rc.Mode = CipherMode.CBC;
if (null != m_Key)
{
rc.Key = m_Key;
}
else
{
m_Key = rc.Key;
}
if (null != m_initVec)
{
rc.IV = m_initVec;
}
else
{
m_initVec = rc.IV;
}
return rc.CreateEncryptor();
}
case EncryptionAlgorithm.Rijndael:
{
Rijndael rijndael = new RijndaelManaged();
rijndael.Mode = CipherMode.CBC;
if (null != m_Key)
{
rijndael.Key = m_Key;
}
else
{
m_Key = rijndael.Key;
}
if (null != m_initVec)
{
rijndael.IV = m_initVec;
}
else
{
m_initVec = rijndael.IV;
}
return rijndael.CreateEncryptor();
}
case EncryptionAlgorithm.TripleDes:
{
TripleDES edes = new TripleDESCryptoServiceProvider();
edes.Mode = CipherMode.CBC;
if (null != m_Key)
{
edes.Key = m_Key;
}
else
{
m_Key = edes.Key;
}
if (null != m_initVec)
{
edes.IV = m_initVec;
}
else
{
m_initVec = edes.IV;
}
return edes.CreateEncryptor();
}
default:
throw new CryptographicException("Algorithm ID '" + algorithm + "' not supported.");
} } /// <summary>
/// 提供具体实现解密的方法
/// </summary>
/// <param name="algorithm"></param>
/// <param name="bytesData">需要解密的信息</param>
/// <returns></returns>
public byte[] Decrypt(EncryptionAlgorithm algorithm, byte[] bytesData)
{
byte[] result = new byte[];
using (MemoryStream stream = new MemoryStream())
{
ICryptoTransform cryptoServiceProvider = GetDecryptoServiceProvider(algorithm);
using (CryptoStream stream2 = new CryptoStream(stream, cryptoServiceProvider, CryptoStreamMode.Write))
{
try
{
stream2.Write(bytesData, , bytesData.Length);
stream2.FlushFinalBlock();
stream2.Close();
result = stream.ToArray();
}
catch (Exception exception)
{
throw new Exception("Error while writing decrypted data to the stream: \n" + exception.Message);
}
}
stream.Close();
}
return result;
}
/// <summary>
/// 提供具体实现加密的方法
/// </summary>
/// <param name="algorithm"></param>
/// <param name="bytesData">需要加密的信息</param>
/// <returns></returns>
public byte[] Encrypt(EncryptionAlgorithm algorithm, byte[] bytesData)
{
byte[] result = new byte[];
using (MemoryStream stream = new MemoryStream())
{
ICryptoTransform cryptoServiceProvider = this.GetEncryptoServiceProvider(algorithm);
using (CryptoStream stream2 = new CryptoStream(stream, cryptoServiceProvider, CryptoStreamMode.Write))
{
try
{
stream2.Write(bytesData, , bytesData.Length);
stream2.FlushFinalBlock();
stream2.Close();
result = stream.ToArray();
}
catch (Exception exception)
{
throw new Exception("Error while writing encrypted data to the stream: \n" + exception.Message);
}
}
stream.Close();
}
return result;
} }