在开发内部系统当中，我们经常使用参数进行传递，但由于明文传递会涉及到安全问题。所以我们一般都是加密明文再和明文一起传递，接受方再检测是否被明文是否中途被篡改。
表达不好，还是看代码吧！
上图是我对字符串加密和解密后的对照图。
下面是才是我调用的类：
/// <summary> /// 对称加密处理类 /// </summary> public class SymmCrypt { private SymmetricAlgorithm mobjCryptoService; public enum SymmProvEnum { DES, RC2, Rijndael } public SymmCrypt() { this.mobjCryptoService = new DESCryptoServiceProvider(); } /// <summary> /// 构造函数，选择加密方式 /// </summary> /// <param name="encryptType"></param> public SymmCrypt(SymmProvEnum encryptType) { switch (encryptType) { case SymmProvEnum.DES: mobjCryptoService = new DESCryptoServiceProvider(); break; case SymmProvEnum.RC2: mobjCryptoService = new RC2CryptoServiceProvider(); break; case SymmProvEnum.Rijndael: mobjCryptoService = new RijndaelManaged(); break; } } /// <summary> /// 利用MD5加密算法加密 /// </summary> /// <param name="strIN">需要加密的字符串</param> /// <returns>返回加密过的字符串</returns> public static string MD5Encrypt(string strIN) { byte[] tmpByte; MD5 md5 = new MD5CryptoServiceProvider(); tmpByte = md5.ComputeHash(GetBytesBySting(strIN)); md5.Clear(); return GetStringByBytes(tmpByte); } /// <summary> /// 利用SHA1加密算法加密 /// </summary> /// <param name="strIN">需要加密的字符串</param> /// <returns>返回加密过的字符串</returns> public static string SHA1Encrypt(string strIN) { byte[] tmpByte; SHA1 sha1 = new SHA1CryptoServiceProvider(); tmpByte = sha1.ComputeHash(GetBytesBySting(strIN)); sha1.Clear(); return GetStringByBytes(tmpByte); } /// <summary> /// 利用SHA256加密算法加密 /// </summary> /// <param name="strIN">需要加密的字符串</param> /// <returns>返回加密过的字符串</returns> public static string SHA256Encrypt(string strIN) { byte[] tmpByte; SHA256 sha256 = new SHA256Managed(); tmpByte = sha256.ComputeHash(GetBytesBySting(strIN)); sha256.Clear(); return GetStringByBytes(tmpByte); } /// <summary> /// 利用SHA512加密算法加密 /// </summary> /// <param name="strIN">需要加密的字符串</param> /// <returns>返回加密过的字符串</returns> public static string SHA512Encrypt(string strIN) { byte[] tmpByte; SHA512 sha512 = new SHA512Managed(); tmpByte = sha512.ComputeHash(GetBytesBySting(strIN)); sha512.Clear(); return GetStringByBytes(tmpByte); } #region Base64加密 /// <summary> /// Base64加密 /// </summary> /// <param name="text">要加密的字符串</param> /// <returns></returns> public static string EncodeBase64(string text) { //如果字符串为空，则返回 if (string.IsNullOrEmpty(text)) { return ""; } try { char[] Base64Code = new char[]{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T', 'U','V','W','X','Y','Z','a','b','c','d','e','f','g','h','i','j','k','l','m','n', 'o','p','q','r','s','t','u','v','w','x','y','z','0','1','2','3','4','5','6','7', '8','9','+','/','='}; byte empty = (byte)0; ArrayList byteMessage = new ArrayList(Encoding.Default.GetBytes(text)); StringBuilder outmessage; int messageLen = byteMessage.Count; int page = messageLen / 3; int use = 0; if ((use = messageLen % 3) > 0) { for (int i = 0; i < 3 - use; i++) byteMessage.Add(empty); page++; } outmessage = new System.Text.StringBuilder(page * 4); for (int i = 0; i < page; i++) { byte[] instr = new byte[3]; instr[0] = (byte)byteMessage[i * 3]; instr[1] = (byte)byteMessage[i * 3 + 1]; instr[2] = (byte)byteMessage[i * 3 + 2]; int[] outstr = new int[4]; outstr[0] = instr[0] >> 2; outstr[1] = ((instr[0] & 0x03) << 4) ^ (instr[1] >> 4); if (!instr[1].Equals(empty)) outstr[2] = ((instr[1] & 0x0f) << 2) ^ (instr[2] >> 6); else outstr[2] = 64; if (!instr[2].Equals(empty)) outstr[3] = (instr[2] & 0x3f); else outstr[3] = 64; outmessage.Append(Base64Code[outstr[0]]); outmessage.Append(Base64Code[outstr[1]]); outmessage.Append(Base64Code[outstr[2]]); outmessage.Append(Base64Code[outstr[3]]); } return outmessage.ToString(); } catch (Exception ex) { throw ex; } } #endregion #region Base64解密 /// <summary> /// Base64解密 /// </summary> /// <param name="text">要解密的字符串</param> public static string DecodeBase64(string text) { ////如果字符串为空，则返回 //if (ValidationHelper.IsNullOrEmpty<string>(text)) //{ // return ""; //} //将空格替换为加号 text = text.Replace(" ", "+"); try { if ((text.Length % 4) != 0) { return "包含不正确的BASE64编码"; } if (!Regex.IsMatch(text, "^[A-Z0-9/+=]*$", RegexOptions.IgnoreCase)) { return "包含不正确的BASE64编码"; } string Base64Code = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; int page = text.Length / 4; ArrayList outMessage = new ArrayList(page * 3); char[] message = text.ToCharArray(); for (int i = 0; i < page; i++) { byte[] instr = new byte[4]; instr[0] = (byte)Base64Code.IndexOf(message[i * 4]); instr[1] = (byte)Base64Code.IndexOf(message[i * 4 + 1]); instr[2] = (byte)Base64Code.IndexOf(message[i * 4 + 2]); instr[3] = (byte)Base64Code.IndexOf(message[i * 4 + 3]); byte[] outstr = new byte[3]; outstr[0] = (byte)((instr[0] << 2) ^ ((instr[1] & 0x30) >> 4)); if (instr[2] != 64) { outstr[1] = (byte)((instr[1] << 4) ^ ((instr[2] & 0x3c) >> 2)); } else { outstr[2] = 0; } if (instr[3] != 64) { outstr[2] = (byte)((instr[2] << 6) ^ instr[3]); } else { outstr[2] = 0; } outMessage.Add(outstr[0]); if (outstr[1] != 0) outMessage.Add(outstr[1]); if (outstr[2] != 0) outMessage.Add(outstr[2]); } byte[] outbyte = (byte[])outMessage.ToArray(Type.GetType("System.Byte")); return Encoding.Default.GetString(outbyte); } catch (Exception ex) { throw ex; } } #endregion /// <summary> /// 把字节转换成字符串 /// </summary> /// <param name="Byte">需要转换字节数组</param> /// <returns>转换后的字符串</returns> private static string GetStringByBytes(byte[] Byte) { string tmpString = ""; //tmpString = UTF8Encoding.Default.GetString(Byte); tmpString = BitConverter.ToString(Byte); return tmpString; } /// <summary> /// 把字符串转换成字节数组 /// </summary> /// <param name="strKey">需要转换的字符串</param> /// <returns>转换后的字节数组</returns> private static byte[] GetBytesBySting(string strKey) { int tmpStrLen = strKey.Length; byte[] tmpByte = new byte[tmpStrLen - 1]; tmpByte = UTF8Encoding.Default.GetBytes(strKey); return tmpByte; } /// <summary> /// 获取Key的字节 /// </summary> /// <param name="keyString">Key字符串</param> /// <returns>转换后的字节形式</returns> private byte[] GetKeyBytes(string keyString) { string sTemp = ""; if (mobjCryptoService.LegalKeySizes.Length > 0) { int lessSize = 0; int moreSize = mobjCryptoService.LegalKeySizes[0].MinSize; while (keyString.Length * 8 > moreSize) { lessSize = moreSize; moreSize += mobjCryptoService.LegalKeySizes[0].SkipSize; System.Threading.Thread.Sleep(0); } sTemp = keyString.PadRight(moreSize / 8, '_'); } else sTemp = keyString; return ASCIIEncoding.ASCII.GetBytes(sTemp); } /// <summary> /// 获取IV向量的字节 /// </summary> /// <param name="ivString">IV向量字符串</param> /// <returns>转换后的字节形式</returns> private byte[] GetIvBytes(string ivString) { ivString += "diksk.sl"; ivString = ivString.Substring(0, this.mobjCryptoService.IV.Length); return ASCIIEncoding.ASCII.GetBytes(ivString); } /// <summary> /// 对输入的字符串进行加密 /// </summary> /// <param name="sourceString">需要加密的原始字符串</param> /// <param name="keyString">加密密钥</param> /// <param name="ivString">加密向量</param> /// <returns>加密后的字符串</returns> public string Encrypt(string sourceString, string keyString, string ivString) { byte[] data = Encoding.Default.GetBytes(sourceString); byte[] result; mobjCryptoService.Key = GetKeyBytes(keyString); mobjCryptoService.IV = GetIvBytes(ivString); ICryptoTransform desencrypt = mobjCryptoService.CreateEncryptor(); result = desencrypt.TransformFinalBlock(data, 0, data.Length); string desString = ""; for (int i = 0; i < result.Length; i++) { desString += result[i].ToString() + "-"; } //return desString.TrimEnd('-'); return BitConverter.ToString(result); } /// <summary> /// 对输入的密文字符串进行解密 /// </summary> /// <param name="sourceString">需要解密的密文字符串</param> /// <param name="keyString">解密密钥</param> /// <param name="ivString">解密向量</param> /// <returns>解密后的原始字符串</returns> public string Decrypt(string sourceString, string keyString, string ivString) { try { string[] sInput = sourceString.Split("-".ToCharArray()); byte[] data = new byte[sInput.Length]; byte[] result; for (int i = 0; i < sInput.Length; i++) data[i] = byte.Parse(sInput[i], System.Globalization.NumberStyles.HexNumber); mobjCryptoService.Key = GetKeyBytes(keyString); mobjCryptoService.IV = GetIvBytes(ivString); ICryptoTransform desencrypt = mobjCryptoService.CreateDecryptor(); result = desencrypt.TransformFinalBlock(data, 0, data.Length); return Encoding.Default.GetString(result); } catch { return "error"; } } }