/// <summary>
/// �����û��������룬����ʹ�õĽ����㷨����ɶ�ָ���ַ����Ľ��ܣ�
/// <remarks>ָ���Ľ����㷨������ַ���ʹ�ü��ܵ��㷨һ��
/// �����㷨����������ͳ�ʼ��ƫ������Ҫ��һ��
/// DES��RC2:�������볤�Ⱥͳ�ʼ��ƫ�������� ������4���ַ�;
/// Rijndael:�������볤�ȿ�����12,16���ַ�,��ʼ��ƫ����Ϊ8���ַ�;
/// TripleDes:�������볤�ȿ���Ϊ8����12���ַ�,��ʼ��ƫ����Ϊ4���ַ�;
/// </summary>
/// <param name="plainText">������������</param>
/// <param name="algorithm">ʹ�õļ����㷨</param>
/// <param name="userInitialVector">����ʱʹ�õ���ʼƫ����</param>
/// <param name="encryptionText">���ܺ���ַ���</param>
/// <returns></returns>
public static string Decrypt(string plainText, EncryptionAlgorithm algorithm, string userInitialVector, string encryptionText)
{
string result = string.Empty;
SetKey(algorithm, plainText);
SetInitialVector(algorithm, userInitialVector);
EncryptTransform transform = new EncryptTransform(m_Key, m_initVec);
byte[] bytesData = Convert.FromBase64String(encryptionText);
byte[] bytes = null;
try
{
bytes = transform.Decrypt(algorithm, bytesData);
}
catch (Exception exception)
{
throw exception;
}
if (bytes.Length > 0)
{
result = Encoding.Unicode.GetString(bytes);
}
m_Key = transform.Key;
m_initVec = transform.InitVec;
return result;
}