加密解密大汇总

 在项目开发中，出于系统安全考虑，我们总会想到使用加密解密进行处理。首先保证的一点就是数据被窃取后，不能使其正常阅读。其次，就是防止接口随意调用。 （PS：鄙人目前就想到了这两点好处，如果还有什么优点，欢迎给位补充o(^▽^)o）

 接下来就说几个常用的加密算法:DES加密算法，AES加密算法，RSA加密算法，Base64加密算法，MD5加密算法，SHA1加密算法

1.DES加密算法

加密方式---- 使用异或，置换，代换，移位四种基本运算进行16轮循环加密而成。

共分为一般加密和三重加密>>

DES一般加密解密代码实现：

  #region ========加密========

        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="Text"></param>
        /// <returns></returns>
        public static string Encrypt(string Text)
        {
            return Encrypt(Text, "DTcms");
        }
        /// <summary> 
        /// 加密数据 
        /// </summary> 
        /// <param name="Text"></param> 
        /// <param name="sKey"></param> 
        /// <returns></returns> 
        public static string Encrypt(string Text, string sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray;
            inputByteArray = Encoding.Default.GetBytes(Text);
            des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            return ret.ToString();
        }

        #endregion

        #region ========解密========

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="Text"></param>
        /// <returns></returns>
        public static string Decrypt(string Text)
        {
            return Decrypt(Text, "DTcms");
        }
        /// <summary> 
        /// 解密数据 
        /// </summary> 
        /// <param name="Text"></param> 
        /// <param name="sKey"></param> 
        /// <returns></returns> 
        public static string Decrypt(string Text, string sKey)
        {
            try
            {
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                int len;
                len = Text.Length / 2;
                byte[] inputByteArray = new byte[len];
                int x, i;
                for (x = 0; x < len; x++)
                {
                    i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
                    inputByteArray[x] = (byte)i;
                }
                des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
                des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                return Encoding.Default.GetString(ms.ToArray());
            }
            catch
            {
                return "";
            }

        }

        #endregion

3DES（三重DES加密）实现

    #region======加密==========
        public static string DES3Encrypt(string Text)
        {
            return DES3Encrypt(Text, "DTcms");
        }

        public static string DES3Encrypt(string strString, string strKey)
        {
            TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();
            MD5CryptoServiceProvider hashMD5 = new MD5CryptoServiceProvider();
            DES.Key = hashMD5.ComputeHash(Encoding.Default.GetBytes(strKey));
            DES.Mode = CipherMode.ECB; ICryptoTransform DESEncrypt = DES.CreateEncryptor();
            byte[] Buffer = Encoding.Default.GetBytes(strString);
            return Convert.ToBase64String(DESEncrypt.TransformFinalBlock(Buffer, 0, Buffer.Length));
        }

        #endregion
        #region======解密===========
        public static string DES3Decrypt(string Text)
        {
            return DES3Decrypt(Text, "DTcms");
        }

        public static string DES3Decrypt(string strString, string strKey)
        {
            TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();
            MD5CryptoServiceProvider hashMD5 = new MD5CryptoServiceProvider();
            DES.Key = hashMD5.ComputeHash(Encoding.Default.GetBytes(strKey));

            DES.Mode = CipherMode.ECB; ICryptoTransform DESDecrypt = DES.CreateDecryptor();

            string result = "";
            try
            {
                byte[] Buffer = Convert.FromBase64String(strString);
                result = Encoding.Default.GetString(DESDecrypt.TransformFinalBlock(Buffer, 0, Buffer.Length));
            }
            catch (System.Exception e)
            {
                throw (new System.Exception("null", e));
            }
            return result;

        }
        #endregion

2.AES加密实现

这个代替了上面的DES，称为高级加密标准

加密方式---1、密钥扩展（KeyExpansion），2、初始轮（Initial Round），3、重复轮（Rounds），每一轮又包括：SubBytes、ShiftRows、MixColumns、AddRoundKey，4、最终轮（Final Round），最终轮没有MixColumns。

根据参数分为三种>>

参数是byte[]类型的：

#region  
  
       /// <summary>  
       /// AES加密  
       /// </summary>  
       /// <param name="Data">被加密的明文</param>  
       /// <param name="Key">密钥</param>  
       /// <param name="Vector">向量</param>  
       /// <returns>密文</returns>  
       public static Byte[] AESEncrypt(Byte[] Data, String Key, String Vector)  
       {  
           Byte[] bKey = new Byte[32];  
           Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);  
           Byte[] bVector = new Byte[16];  
           Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);  
           Byte[] Cryptograph = null; // 加密后的密文  
           Rijndael Aes = Rijndael.Create();  
           try  
           {  
               // 开辟一块内存流  
               using (MemoryStream Memory = new MemoryStream())  
               {  
                   // 把内存流对象包装成加密流对象  
                   using (CryptoStream Encryptor = new CryptoStream(Memory,  
                    Aes.CreateEncryptor(bKey, bVector),  
                    CryptoStreamMode.Write))  
                   {  
                       // 明文数据写入加密流  
                       Encryptor.Write(Data, 0, Data.Length);  
                       Encryptor.FlushFinalBlock();  
  
                       Cryptograph = Memory.ToArray();  
                   }  
               }  
           }  
           catch  
           {  
               Cryptograph = null;  
           }  
           return Cryptograph;  
       }  
  
       /// <summary>  
       /// AES解密  
       /// </summary>  
       /// <param name="Data">被解密的密文</param>  
       /// <param name="Key">密钥</param>  
       /// <param name="Vector">向量</param>  
       /// <returns>明文</returns>  
       public static Byte[] AESDecrypt(Byte[] Data, String Key, String Vector)  
       {  
           Byte[] bKey = new Byte[32];  
           Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);  
           Byte[] bVector = new Byte[16];  
           Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);  
  
           Byte[] original = null; // 解密后的明文  
  
           Rijndael Aes = Rijndael.Create();  
           try  
           {  
               // 开辟一块内存流，存储密文  
               using (MemoryStream Memory = new MemoryStream(Data))  
               {  
                   // 把内存流对象包装成加密流对象  
                   using (CryptoStream Decryptor = new CryptoStream(Memory,  
                   Aes.CreateDecryptor(bKey, bVector),  
                   CryptoStreamMode.Read))  
                   {  
                       // 明文存储区  
                       using (MemoryStream originalMemory = new MemoryStream())  
                       {  
                           Byte[] Buffer = new Byte[1024];  
                           Int32 readBytes = 0;  
                           while ((readBytes = Decryptor.Read(Buffer, 0, Buffer.Length)) > 0)  
                           {  
                               originalMemory.Write(Buffer, 0, readBytes);  
                           }  
  
                           original = originalMemory.ToArray();  
                       }  
                   }  
               }  
           }  
           catch  
           {  
               original = null;  
           }  
           return original;  
       }  
 
       #endregion   

参数是string类型的：

#region  
  
       /// <summary>  
       /// 获取密钥  
       /// </summary>  
       private static string Key  
       {  
           get { return @")O[NB]6,YF}+efcaj{+oESb9d8>Z'e9M"; }  
       }  
  
       /// <summary>  
       /// 获取向量  
       /// </summary>  
       private static string IV  
       {  
           get { return @"L+~f4,Ir)b$=pkf"; }  
       }  
  
       /// <summary>  
       /// AES加密  
       /// </summary>  
       /// <param name="plainStr">明文字符串</param>  
       /// <returns>密文</returns>  
       public static string AESEncrypt(string plainStr)  
       {  
           byte[] bKey = Encoding.UTF8.GetBytes(Key);  
           byte[] bIV = Encoding.UTF8.GetBytes(IV);  
           byte[] byteArray = Encoding.UTF8.GetBytes(plainStr);  
  
           string encrypt = null;  
           Rijndael aes = Rijndael.Create();  
           using (MemoryStream mStream = new MemoryStream())  
           {  
               using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write))  
               {  
                   cStream.Write(byteArray, 0, byteArray.Length);  
                   cStream.FlushFinalBlock();  
                   encrypt = Convert.ToBase64String(mStream.ToArray());  
               }  
           }  
           aes.Clear();  
           return encrypt;  
       }  
  
       /// <summary>  
       /// AES加密  
       /// </summary>  
       /// <param name="plainStr">明文字符串</param>  
       /// <param name="returnNull">加密失败时是否返回 null，false 返回 String.Empty</param>  
       /// <returns>密文</returns>  
       public static string AESEncrypt(string plainStr, bool returnNull)  
       {  
           string encrypt = AESEncrypt(plainStr);  
           return returnNull ? encrypt : (encrypt == null ? String.Empty : encrypt);  
       }  
  
       /// <summary>  
       /// AES解密  
       /// </summary>  
       /// <param name="encryptStr">密文字符串</param>  
       /// <returns>明文</returns>  
       public static string AESDecrypt(string encryptStr)  
       {  
           byte[] bKey = Encoding.UTF8.GetBytes(Key);  
           byte[] bIV = Encoding.UTF8.GetBytes(IV);  
           byte[] byteArray = Convert.FromBase64String(encryptStr);  
  
           string decrypt = null;  
           Rijndael aes = Rijndael.Create();  
           using (MemoryStream mStream = new MemoryStream())  
           {  
               using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write))  
               {  
                   cStream.Write(byteArray, 0, byteArray.Length);  
                   cStream.FlushFinalBlock();  
                   decrypt = Encoding.UTF8.GetString(mStream.ToArray());  
               }  
           }  
           aes.Clear();  
           return decrypt;  
       }  
  
       /// <summary>  
       /// AES解密  
       /// </summary>  
       /// <param name="encryptStr">密文字符串</param>  
       /// <param name="returnNull">解密失败时是否返回 null，false 返回 String.Empty</param>  
       /// <returns>明文</returns>  
       public static string AESDecrypt(string encryptStr, bool returnNull)  
       {  
           string decrypt = AESDecrypt(encryptStr);  
           return returnNull ? decrypt : (decrypt == null ? String.Empty : decrypt);  
       }  
 
 
       #endregion  

256位AES加密算法，参数是string类型的：

#region  
  
       /// <summary>  
       /// 256位AES加密  
       /// </summary>  
       /// <param name="toEncrypt"></param>  
       /// <returns></returns>  
       public static string Encrypt(string toEncrypt)  
       {  
           // 256-AES key      
           byte[] keyArray = UTF8Encoding.UTF8.GetBytes("12345678901234567890123456789012");  
           byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);  
  
           RijndaelManaged rDel = new RijndaelManaged();  
           rDel.Key = keyArray;  
           rDel.Mode = CipherMode.ECB;  
           rDel.Padding = PaddingMode.PKCS7;  
  
           ICryptoTransform cTransform = rDel.CreateEncryptor();  
           byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);  
  
           return Convert.ToBase64String(resultArray, 0, resultArray.Length);  
       }  
  
       /// <summary>  
       /// 256位AES解密  
       /// </summary>  
       /// <param name="toDecrypt"></param>  
       /// <returns></returns>  
       public static string Decrypt(string toDecrypt)  
       {  
           // 256-AES key      
           byte[] keyArray = UTF8Encoding.UTF8.GetBytes("12345678901234567890123456789012");  
           byte[] toEncryptArray = Convert.FromBase64String(toDecrypt);  
  
           RijndaelManaged rDel = new RijndaelManaged();  
           rDel.Key = keyArray;  
           rDel.Mode = CipherMode.ECB;  
           rDel.Padding = PaddingMode.PKCS7;  
  
           ICryptoTransform cTransform = rDel.CreateDecryptor();  
           byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);  
  
           return UTF8Encoding.UTF8.GetString(resultArray);  
       }  
 
       #endregion  

 3.RSA加密实现

RSA是种非对称加密算法，它比同样级别的对称密码算法要慢1000倍左右。所以一般只用于少量数据加密。

参考： http://blog.csdn.net/llwinnner/article/details/4011936

 4.Base64加密实现

实现原理：

1. Base64使用A--Z,a--z,0--9,+,/ 这64个字符.
    2. 编码原理:将3个字节转换成4个字节( (3 X 8) = 24 = (4 X 6) )先读入3个字节,每读一个字节,左移8位,再右移四次,每次6位,这样就有4个字节了.
    3. 解码原理:将4个字节转换成3个字节.先读入4个6位(用或运算),每次左移6位,再右移3次,每次8位.这样就还原了.

using System;  
using System.Collections.Generic;  
using System.Text;  
  
namespace MyLibs.encrypt  
{  
    public class Base64  
    {  
        private static string base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";//编码后的字符集  
        private static int[] base64DecodeChars = new int[] { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1 };//对应ASICC字符的位置  
        public static string base64encode(string str)  
        { //加密  
            string Out = "";  
            int i = 0, len = str.Length;  
            char c1, c2, c3;  
            while (i < len)  
            {  
                c1 = Convert.ToChar(str[i++] & 0xff);  
                if (i == len)  
                {  
                    Out += base64EncodeChars[c1 >> 2];  
                    Out += base64EncodeChars[(c1 & 0x3) << 4];  
                    Out += "==";  
                    break;  
                }  
                c2 = str[i++];  
                if (i == len)  
                {  
                    Out += base64EncodeChars[c1 >> 2];  
                    Out += base64EncodeChars[((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4)];  
                    Out += base64EncodeChars[(c2 & 0xF) << 2];  
                    Out += "=";  
                    break;  
                }  
                c3 = str[i++];  
                Out += base64EncodeChars[c1 >> 2];  
                Out += base64EncodeChars[((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4)];  
                Out += base64EncodeChars[((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6)];  
                Out += base64EncodeChars[c3 & 0x3F];  
            }  
            return Out;  
        }  
        public string utf16to8(string str)  
        {  
            string Out = "";  
            int i, len;  
            char c;//char为16位Unicode字符,范围0~0xffff,感谢vczh提醒  
            len = str.Length;  
            for (i = 0; i < len; i++)  
            {//根据字符的不同范围分别转化  
                c = str[i];  
                if ((c >= 0x0001) && (c <= 0x007F))  
                {  
                    Out += str[i];  
                }  
                else if (c > 0x07FF)  
                {  
                    Out += (char)(0xE0 | ((c >> 12) & 0x0F));  
                    Out += (char)(0x80 | ((c >> 6) & 0x3F));  
                    Out += (char)(0x80 | ((c >> 0) & 0x3F));  
                }  
                else  
                {  
                    Out += (char)(0xC0 | ((c >> 6) & 0x1F));  
                    Out += (char)(0x80 | ((c >> 0) & 0x3F));  
                }  
            }  
            return Out;  
        }  
  
        public static string base64decode(string str)  
        {//解密  
            int c1, c2, c3, c4;  
            int i, len;  
            string Out;  
            len = str.Length;  
            i = 0; Out = "";  
            while (i < len)  
            {  
                do  
                {  
                    c1 = base64DecodeChars[str[i++] & 0xff];  
                } while (i < len && c1 == -1);  
                if (c1 == -1) break;  
                do  
                {  
                    c2 = base64DecodeChars[str[i++] & 0xff];  
                } while (i < len && c2 == -1);  
                if (c2 == -1) break;  
                Out += (char)((c1 << 2) | ((c2 & 0x30) >> 4));  
                do  
                {  
                    c3 = str[i++] & 0xff;  
                    if (c3 == 61) return Out;  
                    c3 = base64DecodeChars[c3];  
                } while (i < len && c3 == -1);  
                if (c3 == -1) break;  
                Out += (char)(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));  
                do  
                {  
                    c4 = str[i++] & 0xff;  
                    if (c4 == 61) return Out;  
                    c4 = base64DecodeChars[c4];  
                } while (i < len && c4 == -1);  
                if (c4 == -1) break;  
                Out += (char)(((c3 & 0x03) << 6) | c4);  
            }  
            return Out;  
        }  
  
        public string utf8to16(string str)  
        {  
            string Out = "";  
            int i, len;  
            char c, char2, char3;  
            len = str.Length;  
            i = 0; while (i < len)  
            {  
                c = str[i++];  
                switch (c >> 4)  
                {  
                    case 0:  
                    case 1:  
                    case 2:  
                    case 3:  
                    case 4:  
                    case 5:  
                    case 6:  
                    case 7: Out += str[i - 1]; break;  
                    case 12:  
                    case 13: char2 = str[i++];  
                        Out += (char)(((c & 0x1F) << 6) | (char2 & 0x3F)); break;  
                    case 14: char2 = str[i++];  
                        char3 = str[i++];  
                        Out += (char)(((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0)); break;  
                }  
            }  
            return Out;  
        }  
  
    }  
}  

5.MD5加密实现

  MD5功能：
    输入任意长度的信息，经过处理，输出为128位的信息（数字指纹）；
    不同的输入得到的不同的结果（唯一性）；
    根据128位的输出结果不可能反推出输入的信息（不可逆）； 

作用：1、防止被篡改：    2、防止直接看到明文： 3、防止抵赖（数字签名）：

参考：http://www.cnblogs.com/healer007/p/5062189.html

6.SHA1加密实现

SHA1加密和MD5一样都是不可逆的，效率也都差不多。

  #region 获取由SHA1加密的字符串
        public static string EncryptToSHA1(string str)
        {
            SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
            byte[] str1 = Encoding.UTF8.GetBytes(str);
            byte[] str2 = sha1.ComputeHash(str1);
            sha1.Clear();
            (sha1 as IDisposable).Dispose();
            return Convert.ToBase64String(str2);
        }
        #endregion