public static class EncryptionHelper { #region const /// <summary> /// 默认使用的适合于DES,RC2算法的Key /// </summary> private const string m_ShortDefaultKey = "Nesc"; /// <summary> /// 默认使用的TRIPLEDES，RIJNDAEL算法的Key /// </summary> private const string m_LongDefaultKey = "Nesc.Oversea"; /// <summary> /// 默认使用的适合于DES,RC2,TRIPLEDES算法的InitVector /// </summary> private const string m_ShortDefaultIV = "2001"; /// <summary> /// 默认使用的适合于RIJNDAEL算法的InitVector /// </summary> private const string m_LongDefaultIV = "Oversea3"; #endregion private static byte[] m_Key = null; private static byte[] m_initVec = null; #region properties /// <summary> /// 使用的加密明文密码 /// </summary> public static string Key { get { string result = string.Empty; if (m_Key != null) { result = Encoding.Unicode.GetString(m_Key); } return result; } } /// <summary> /// 使用加密的起始偏移量 /// </summary> public static string InitVector { get { string result = string.Empty; if (m_initVec != null) { result = Encoding.Unicode.GetString(m_initVec); } return result; } } #endregion /// <summary> /// 接受用户明文密码，本次加密使用的算法，完成对指定字符串的加密 /// <example><![CDATA[string result = EncryptionHelper.Encrypt("1234", EncryptionAlgorithm.Rc2, "5678", text);]]></example> /// <remarks>各个算法对明文密码和初始化偏移量的要求不一样 /// DES和RC2:明文密码长度和初始化偏移量长度 必须是4个字符; /// Rijndael:明文密码长度可以是12,16个字符,初始化偏移量为8个字符; /// TripleDes:明文密码长度可以为8个和12个字符,初始化偏移量为4个字符; /// 注意:如果提供的明文密码和偏移量不符合算法的标准,将使用随机密码,使用者在加密后通过提供的Key和InitVector属性获得加密时使用的明文密码和偏移量 /// </remarks> /// </summary> /// <param name="plainText">使用的加密明文密码</param> /// <param name="algorithm">加密算法枚举对象</param> /// <param name="userInitialVector">使用的加密起始偏移量</param> /// <param name="encryptionText">需要加密的字符</param> /// <returns></returns> public static string Encrypt(string plainText, EncryptionAlgorithm algorithm, string userInitialVector, string encryptionText) { string result = string.Empty; if (encryptionText.Length > 0) { SetKey(algorithm, plainText); SetInitialVector(algorithm, userInitialVector); EncryptTransform transform = new EncryptTransform(m_Key,m_initVec); byte[] bytes = Encoding.Unicode.GetBytes(encryptionText); byte[] inArray = transform.Encrypt(algorithm, bytes); if (inArray.Length > 0) { result = Convert.ToBase64String(inArray); } m_Key = transform.Key; m_initVec = transform.InitVec; } return result; } /// <summary> /// 指定需要加密的字符串使用默认的明文密码和算法(DES)进行加密 /// </summary> /// <param name="encryptionText"></param> /// <returns></returns> public static string Encrypt(string encryptionText) { string result = string.Empty; result = Encrypt(m_ShortDefaultKey, EncryptionAlgorithm.Des, m_ShortDefaultIV, encryptionText); return result; } /// <summary> /// 指定需要加密的字符串和算法使用默认的明文密码进行加密 /// </summary> /// <param name="algorithm"></param> /// <param name="encryptionText"></param> /// <returns></returns> public static string Encrypt(EncryptionAlgorithm algorithm, string encryptionText) { string result = string.Empty; string key = GetDefaultKey(algorithm); string iv = GetDefaultIV(algorithm); result = Encrypt(key, algorithm, iv, encryptionText); return result; } /// <summary> /// 接受用户明文密码，使用默认的加密算法完成对指定字符串的加密 /// <remarks>默认为DES算法进行加密</remarks> /// <example><![CDATA[string result = EncryptionHelper.Encrypt("1234", "5678", text);]]></example> /// </summary> /// <param name="plainText">使用的加密明文密码</param> /// <param name="userInitialVector">使用的加密起始偏移量</param> /// <param name="encryptionText">需要加密的字符串</param> /// <returns>加密后的字符串</returns> public static string Encrypt(string plainText, string userInitialVector, string encryptionText) { string result = string.Empty; result = Encrypt(plainText, EncryptionAlgorithm.Des, userInitialVector, encryptionText); return result; } /// <summary> /// 接受用户明文密码，本次使用的解密算法，完成对指定字符串的解密； /// <remarks>指定的解密算法必须和字符串使用加密的算法一致 /// 各个算法对明文密码和初始化偏移量的要求不一样 /// DES和RC2:明文密码长度和初始化偏移量长度 必须是4个字符; /// Rijndael:明文密码长度可以是12,16个字符,初始化偏移量为8个字符; /// TripleDes:明文密码长度可以为8个和12个字符,初始化偏移量为4个字符; /// </summary> /// <param name="plainText">加密明文密码</param> /// <param name="algorithm">使用的加密算法</param> /// <param name="userInitialVector">加密时使用的起始偏移量</param> /// <param name="encryptionText">加密后的字符串</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; } /// <summary> /// 接受用户明文密码，使用默认解密算法完成对指定字符串的解密 /// </summary> /// <param name="plainText">加密时使用的明文密码</param> /// <param name="userInitialVector">加密时使用的起始偏移量</param> /// <param name="encryptionText">加密后的字符串</param> /// <returns></returns> public static string Decrypt(string plainText, string userInitialVector, string encryptionText) { string result = string.Empty; result=Decrypt(plainText, EncryptionAlgorithm.Des,userInitialVector,encryptionText); return result; } /// <summary> /// 使用默认的算法(DES)和默认的明文密码进行解密 /// </summary> /// <param name="encryptionText"></param> /// <returns></returns> public static string Decrypt(string encryptionText) { string result = string.Empty; result = Decrypt(m_ShortDefaultKey, EncryptionAlgorithm.Des, m_ShortDefaultIV, encryptionText); return result; } /// <summary> /// 指定加密时使用的算法,使用默认的明文密码进行解密 /// </summary> /// <param name="algorithm"></param> /// <param name="encryptionText"></param> /// <returns></returns> public static string Decrypt(EncryptionAlgorithm algorithm,string encryptionText) { string result = string.Empty; string key = GetDefaultKey(algorithm); string iv = GetDefaultIV(algorithm); result = Decrypt(key, algorithm, iv, encryptionText); return result; } /// <summary> /// 根据算法获得默认的Key /// </summary> /// <param name="algorithm"></param> /// <returns></returns> private static string GetDefaultKey(EncryptionAlgorithm algorithm) { string result = m_ShortDefaultKey; switch (algorithm) { case EncryptionAlgorithm.Rijndael: { result = m_LongDefaultKey; break; } case EncryptionAlgorithm.TripleDes: { result = m_LongDefaultKey; break; } } return result; } /// <summary> /// 根据算法获得默认的IV /// </summary> /// <param name="algorithm"></param> /// <returns></returns> private static string GetDefaultIV(EncryptionAlgorithm algorithm) { string result = m_ShortDefaultIV; switch (algorithm) { case EncryptionAlgorithm.Rijndael: { result = m_LongDefaultIV; break; } } return result; } /// <summary> /// /// </summary> /// <param name="algorithm"></param> /// <param name="initialVector"></param> /// <returns></returns> private static void SetInitialVector(EncryptionAlgorithm algorithm, string initialVector) { if (null != initialVector) { byte[] bytes = Encoding.Unicode.GetBytes(initialVector); switch (algorithm) { case EncryptionAlgorithm.Des: { if ( bytes.Length == 8) { m_initVec = bytes; } break; } case EncryptionAlgorithm.Rc2: { if ( bytes.Length == 8) { m_initVec = bytes; } break; } case EncryptionAlgorithm.Rijndael: { if ( bytes.Length ==16) { m_initVec = bytes; } break; } case EncryptionAlgorithm.TripleDes: { if (bytes.Length == 8) { m_initVec = bytes; } break; } } } } private static void SetKey(EncryptionAlgorithm algorithm, string key) { if (null != key) { byte[] keyByte = Encoding.Unicode.GetBytes(key); switch (algorithm) { case EncryptionAlgorithm.Des: { if (keyByte.Length== 8) { m_Key = keyByte; } break; } case EncryptionAlgorithm.Rc2: { if (keyByte.Length == 8) { m_Key = keyByte; } break; } case EncryptionAlgorithm.Rijndael: { if (keyByte.Length==24 || (keyByte.Length == 32)) { m_Key = keyByte; } break; } case EncryptionAlgorithm.TripleDes: { if (keyByte.Length ==16 ||(keyByte.Length == 24)) { m_Key = keyByte; } break; } } } } }