谈谈数据加密的处理

1、谈谈数据加密的处理-提供各种算法处理 数据的加密重要性大家皆知，很多情况下需要对数据进行加密处理，但各种重要数据的加密要求不一样，有些需要时可逆的，有些是不要求可逆的，可逆的一般称之为对称加密算法，不可逆的一般可以成为非对称加密算法。如登录密码，一般较好的方式是采用不可逆的加密算法，如MD5、SHA256、哈希数值等，当然也有的采用可逆的强度好一些的加密方式，在选择加密键值的时候，变化一下也算是比较不错的选择。另外一些为了掩人耳目或者不让别人直接可以查看到，就采用其他的加密算法，如DES加密算法、AES的RijndaelManaged加密算法，或者也可以采用Base64加密，甚至我看到一个很变

2、态的方式，就是用MD5加密的头，内容则采用Base64的方式加密，一般不知道内情的还真的不好处理。 在吉日走火入魔失眠夜浅谈管理软件信息安全，用户名、密码的加密解密【附C#配套加密解密源码】 的文章中也对加密做了一些介绍和分析，并贴出了MD5、DES的加密方式代码，吉日的文章图文并茂、哲理及诙谐例子并存，本文有感而发，做一些补充，希望园子同行共通过切磋，交流心得。 加密字符串的方式有很多，也都可以通过这样的加密文件内容，不过较好的方式可能是采用DES及AES两种方式来加密文件了，下面贴出的代码中包含了加解密文件的算法。下面具体贴出本人收藏的各种加密算法代码。 1、DES加密字符串及文件等 如果

3、想可逆的算法，这种方式一般不错，只要结合动态密钥，就可以做出强度比较高的加密应用了。  #region DES对称加密解密 public const string DEFAULT_ENCRYPT_KEY = "12345678"/ <summary>/ 使用默认加密/ </summary>/ <param name="strText"></param>/ <returns></returns>public static string DesEncrypt(string st

4、rText)        try            return DesEncrypt(strText, DEFAULT_ENCRYPT_KEY);            catch          &

5、#160; return ""                    / <summary>/ 使用默认解密/ </summary>/ <param name="strText"></param>/ <returns></returns>public static string DesDecrypt(str

6、ing strText)        try            return DesDecrypt(strText, DEFAULT_ENCRYPT_KEY);            catch         &

7、#160;  return ""                    / <summary>/ Encrypt the string / Attention:key must be 8 bits / </summary>/ <param name="strText">string</param>/ <param

8、name="strEncrKey">key</param>/ <returns></returns>public static string DesEncrypt(string strText, string strEncrKey)        byte byKey = null;byte IV = 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF ;     

9、0;      byKey = Encoding.UTF8.GetBytes(strEncrKey.Substring(0, 8);            DESCryptoServiceProvider des = new DESCryptoServiceProvider();byte inputByteArray = Encoding.UTF8.GetBytes(strText);    &#

10、160;       MemoryStream ms = new MemoryStream();            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write);          

11、  cs.Write(inputByteArray, 0, inputByteArray.Length);            cs.FlushFinalBlock();return Convert.ToBase64String(ms.ToArray();        / <summary>/ Decrypt string / Attention:key must be 8 bits / &

12、lt;/summary>/ <param name="strText">Decrypt string</param>/ <param name="sDecrKey">key</param>/ <returns>output string</returns>public static string DesDecrypt(string strText, string sDecrKey)        byte b

13、yKey = null;byte IV = 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF ;byte inputByteArray = new BytestrText.Length;            byKey = Encoding.UTF8.GetBytes(sDecrKey.Substring(0, 8);          &#

14、160; DESCryptoServiceProvider des = new DESCryptoServiceProvider();            inputByteArray = Convert.FromBase64String(strText);            MemoryStream ms = new MemoryStream();  

15、;          CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write);            cs.Write(inputByteArray, 0, inputByteArray.Length);     &

16、#160;      cs.FlushFinalBlock();            Encoding encoding = new UTF8Encoding();return encoding.GetString(ms.ToArray();        / <summary>/ Encrypt files / Attention:key must b

17、e 8 bits / </summary>/ <param name="m_InFilePath">Encrypt file path</param>/ <param name="m_OutFilePath">output file</param>/ <param name="strEncrKey">key</param>public static void DesEncrypt(string m_InFilePath, string m_OutFil

18、ePath, string strEncrKey)        byte byKey = null;byte IV = 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF ;            byKey = Encoding.UTF8.GetBytes(strEncrKey.Substring(0, 8);     &

19、#160;      FileStream fin = new FileStream(m_InFilePath, FileMode.Open, FileAccess.Read);            FileStream fout = new FileStream(m_OutFilePath, FileMode.OpenOrCreate, FileAccess.Write);     

20、       fout.SetLength(0);/Create variables to help with read and write. byte bin = new byte100; /This is intermediate storage for the encryption. long rdlen = 0; /This is the total number of bytes written. long totlen = fin.Length; /This is the total length of the input

21、 file. int len; /This is the number of bytes to be written at a time.             DES des = new DESCryptoServiceProvider();            CryptoStream encStream = new CryptoStream(fout, des.Cre

22、ateEncryptor(byKey, IV), CryptoStreamMode.Write);/Read from the input file, then encrypt and write to the output file. while (rdlen < totlen)                           

23、; len = fin.Read(bin, 0, 100);                encStream.Write(bin, 0, len);                rdlen = rdlen + len;      

24、60;                 encStream.Close();            fout.Close();            fin.Close();    

25、0;   / <summary>/ Decrypt files / Attention:key must be 8 bits / </summary>/ <param name="m_InFilePath">Decrypt filepath</param>/ <param name="m_OutFilePath">output filepath</param>/ <param name="sDecrKey">key</para

26、m>public static void DesDecrypt(string m_InFilePath, string m_OutFilePath, string sDecrKey)        byte byKey = null;byte IV = 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF ;            byKey = Encoding.UTF

27、8.GetBytes(sDecrKey.Substring(0, 8);            FileStream fin = new FileStream(m_InFilePath, FileMode.Open, FileAccess.Read);            FileStream fout = new FileStream(m_OutFilePath, File

28、Mode.OpenOrCreate, FileAccess.Write);            fout.SetLength(0);/Create variables to help with read and write. byte bin = new byte100; /This is intermediate storage for the encryption. long rdlen = 0; /This is the total number of bytes writte

29、n. long totlen = fin.Length; /This is the total length of the input file. int len; /This is the number of bytes to be written at a time.             DES des = new DESCryptoServiceProvider();         &

30、#160;  CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write);/Read from the input file, then encrypt and write to the output file. while (rdlen < totlen)               

31、0;            len = fin.Read(bin, 0, 100);                encStream.Write(bin, 0, len);              

32、;  rdlen = rdlen + len;                        encStream.Close();            fout.Close();      

33、0;     fin.Close();        #endregion 2、 对称加密算法AES RijndaelManaged加密解密 #region 对称加密算法AES RijndaelManaged加密解密 private static readonly string Default_AES_Key = "#kim123"private static byte Keys = 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D,

34、 0x79,0x53,0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F ;/ <summary>/ 对称加密算法AES RijndaelManaged加密(RijndaelManaged（AES）算法是块式加密算法)/ </summary>/ <param name="encryptString">待加密字符串</param>/ <returns>加密结果字符串</returns>public static string AES_Encrypt(string encryp

35、tString)        return AES_Encrypt(encryptString, Default_AES_Key);        / <summary>/ 对称加密算法AES RijndaelManaged加密(RijndaelManaged（AES）算法是块式加密算法)/ </summary>/ <param name="encryptString">待加密字符串</par

36、am>/ <param name="encryptKey">加密密钥，须半角字符</param>/ <returns>加密结果字符串</returns>public static string AES_Encrypt(string encryptString, string encryptKey)                    encr

37、yptKey = GetSubString(encryptKey, 32, "");            encryptKey = encryptKey.PadRight(32, ' ');            RijndaelManaged rijndaelProvider = new RijndaelManaged(); &

38、#160;          rijndaelProvider.Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 32);            rijndaelProvider.IV = Keys;            ICryp

39、toTransform rijndaelEncrypt = rijndaelProvider.CreateEncryptor();byte inputData = Encoding.UTF8.GetBytes(encryptString);byte encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData, 0, inputData.Length);return Convert.ToBase64String(encryptedData);        / &

40、lt;summary>/ 对称加密算法AES RijndaelManaged解密字符串/ </summary>/ <param name="decryptString">待解密的字符串</param>/ <returns>解密成功返回解密后的字符串,失败返源串</returns>public static string AES_Decrypt(string decryptString)        return AES_Decrypt(d

41、ecryptString, Default_AES_Key);        / <summary>/ 对称加密算法AES RijndaelManaged解密字符串/ </summary>/ <param name="decryptString">待解密的字符串</param>/ <param name="decryptKey">解密密钥,和加密密钥相同</param>/ <returns>解密成功返回

42、解密后的字符串,失败返回空</returns>public static string AES_Decrypt(string decryptString, string decryptKey)        try                          &

43、#160; decryptKey = GetSubString(decryptKey, 32, "");                decryptKey = decryptKey.PadRight(32, ' ');                Rijnda

44、elManaged rijndaelProvider = new RijndaelManaged();                rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey);                rijndaelP

45、rovider.IV = Keys;                ICryptoTransform rijndaelDecrypt = rijndaelProvider.CreateDecryptor();byte inputData = Convert.FromBase64String(decryptString);byte decryptedData = rijndaelDecrypt.TransformFinalBlock(inputDa

46、ta, 0, inputData.Length);return Encoding.UTF8.GetString(decryptedData);            catch            return string.Empty;           

47、60;       / <summary>/ 按字节长度(按字节,一个汉字为2个字节)取得某字符串的一部分/ </summary>/ <param name="sourceString">源字符串</param>/ <param name="length">所取字符串字节长度</param>/ <param name="tailString">附加字符串(当字符串不够长时，尾部所添加的字符串，

48、一般为".")</param>/ <returns>某字符串的一部分</returns>private static string GetSubString(string sourceString, int length, string tailString)        return GetSubString(sourceString, 0, length, tailString);       

49、 / <summary>/ 按字节长度(按字节,一个汉字为2个字节)取得某字符串的一部分/ </summary>/ <param name="sourceString">源字符串</param>/ <param name="startIndex">索引位置，以0开始</param>/ <param name="length">所取字符串字节长度</param>/ <param name="tailString"&g

50、t;附加字符串(当字符串不够长时，尾部所添加的字符串，一般为".")</param>/ <returns>某字符串的一部分</returns>private static string GetSubString(string sourceString, int startIndex, int length, string tailString)        string myResult = sourceString;/当是日文或韩文时(注:中文的范围:u4e00 -

51、 u9fa5, 日文在u0800 - u4e00, 韩文为xAC00-xD7A3)if (System.Text.RegularExpressions.Regex.IsMatch(sourceString, "u0800-u4e00+") |                System.Text.RegularExpressions.Regex.IsMatch(sourceString, "xAC00-xD7A3+&

52、quot;)            /当截取的起始位置超出字段串长度时if (startIndex >= sourceString.Length)                return string.Empty;         

53、0;      else                return sourceString.Substring(startIndex,                      

54、;                             (length + startIndex) > sourceString.Length) ? (sourceString.Length - startIndex) : length);      

55、;                      /中文字符，如"中国人民abcd123"if (length <= 0)            return string.Empty;       

56、;     byte bytesSource = Encoding.Default.GetBytes(sourceString);/当字符串长度大于起始位置if (bytesSource.Length > startIndex)            int endIndex = bytesSource.Length;/当要截取的长度在字符串的有效长度范围内if (bytesSource.Length > (startIndex +

57、length)                                    endIndex = length + startIndex;         &#

58、160;      else                   /当不在有效范围内时,只取到字符串的结尾                    length = bytesSource.L

59、ength - startIndex;                    tailString = ""                int anResultFlag = new intlength;int nFlag = 0;/字节

60、大于127为双字节字符for (int i = startIndex; i < endIndex; i+)                if (bytesSourcei > 127)                      

61、                      nFlag+;if (nFlag = 3)                          &

62、#160;                         nFlag = 1;                        &

63、#160;                   else                               &

64、#160;            nFlag = 0;                                     &

65、#160;  anResultFlagi = nFlag;                /最后一个字节为双字节字符的一半if (bytesSourceendIndex - 1 > 127) && (anResultFlaglength - 1 = 1)             

66、0;                      length = length + 1;                byte bsResult = new bytelength;     

67、0;          Array.Copy(bytesSource, startIndex, bsResult, 0, length);                myResult = Encoding.Default.GetString(bsResult);        

68、;        myResult = myResult + tailString;return myResult;            return string.Empty;        / <summary>/ 加密文件流/ </summary>/ <param name="fs">

69、</param>/ <returns></returns>public static CryptoStream AES_EncryptStrream(FileStream fs, string decryptKey)                    decryptKey = GetSubString(decryptKey, 32, ""); &#

70、160;          decryptKey = decryptKey.PadRight(32, ' ');            RijndaelManaged rijndaelProvider = new RijndaelManaged();           

71、rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey);            rijndaelProvider.IV = Keys;            ICryptoTransform encrypto = rijndaelProvider.CreateEncryptor();   

72、         CryptoStream cytptostreamEncr = new CryptoStream(fs, encrypto, CryptoStreamMode.Write);return cytptostreamEncr;        / <summary>/ 解密文件流/ </summary>/ <param name="fs"></param>/ <

73、returns></returns>public static CryptoStream AES_DecryptStream(FileStream fs, string decryptKey)                    decryptKey = GetSubString(decryptKey, 32, "");     

74、;       decryptKey = decryptKey.PadRight(32, ' ');            RijndaelManaged rijndaelProvider = new RijndaelManaged();            rijndaelProvider.Key

75、= Encoding.UTF8.GetBytes(decryptKey);            rijndaelProvider.IV = Keys;            ICryptoTransform Decrypto = rijndaelProvider.CreateDecryptor();      

76、60;     CryptoStream cytptostreamDecr = new CryptoStream(fs, Decrypto, CryptoStreamMode.Read);return cytptostreamDecr;        / <summary>/ 对指定文件加密/ </summary>/ <param name="InputFile"></param>/ <param name=&q

77、uot;OutputFile"></param>/ <returns></returns>public static bool AES_EncryptFile(string InputFile, string OutputFile)        try            string decryptKey = ""  &

78、#160;             FileStream fr = new FileStream(InputFile, FileMode.Open);                FileStream fren = new FileStream(OutputFile, FileMode.Create);  

79、              CryptoStream Enfr = AES_EncryptStrream(fren, decryptKey);byte bytearrayinput = new bytefr.Length;                fr.Read(bytearrayinput, 0, bytear

80、rayinput.Length);                Enfr.Write(bytearrayinput, 0, bytearrayinput.Length);                Enfr.Close();      

81、;          fr.Close();                fren.Close();            catch         

82、60;  /文件异常return false;            return true;        / <summary>/ 对指定的文件解压缩/ </summary>/ <param name="InputFile"></param>/ <param name="OutputFile"></

83、param>/ <returns></returns>public static bool AES_DecryptFile(string InputFile, string OutputFile)        try            string decryptKey = ""       

84、         FileStream fr = new FileStream(InputFile, FileMode.Open);                FileStream frde = new FileStream(OutputFile, FileMode.Create);       

85、;         CryptoStream Defr = AES_DecryptStream(fr, decryptKey);byte bytearrayoutput = new byte1024;int m_count = 0;do                        

86、60;           m_count = Defr.Read(bytearrayoutput, 0, bytearrayoutput.Length);                    frde.Write(bytearrayoutput, 0, m_count);if (m_count <

87、bytearrayoutput.Length)break;                while (true);                Defr.Close();          

88、60;     fr.Close();                frde.Close();            catch            /文件异常return false;

89、            return true;        #endregion 3、  Base64加密解密算法 #region Base64加密解密 / <summary>/ Base64是一種使用64基的位置計數法。它使用2的最大次方來代表僅可列印的ASCII 字元。/ 這使它可用來作為電子郵件的傳輸編碼。在Base64中的變數使用字元A-Z、a-z和0-9 ，/ 這樣共有62個字元，

90、用來作為開始的64個數字，最後兩個用來作為數字的符號在不同的/ 系統中而不同。/ Base64加密/ </summary>/ <param name="str"></param>/ <returns></returns>public static string Base64Encrypt(string str)        byte encbuff = System.Text.Encoding.UTF8.GetBytes(str);return

91、 Convert.ToBase64String(encbuff);        / <summary>/ Base64解密/ </summary>/ <param name="str"></param>/ <returns></returns>public static string Base64Decrypt(string str)        byte de

92、cbuff = Convert.FromBase64String(str);return System.Text.Encoding.UTF8.GetString(decbuff);        #endregion 4、 MD5加密及验证 MD5的加密处理应用还是比较多，由于破解难度很大，基本上大型网站或者软件商，密码加密一般采用这种方式居多。 而MD5可以用来获得32、 16、8等全部部分内容加密内容，也可以获取其加密后的哈希值。 / <summary> / 获得32位的MD5加密/ </summary

93、>/ <param name="input"></param>/ <returns></returns>public static string GetMD5_32(string input)                    System.Security.Cryptography.MD5 md5 = System.Security.Cr

94、yptography.MD5.Create();byte data = md5.ComputeHash(System.Text.Encoding.Default.GetBytes(input);            StringBuilder sb = new StringBuilder();for (int i = 0; i < data.Length; i+)         

95、0;                  sb.Append(datai.ToString("x2");            return sb.ToString();        / <summary>/ 获得16位的MD5

96、加密/ </summary>/ <param name="input"></param>/ <returns></returns>public static string GetMD5_16(string input)        return GetMD5_32(input).Substring(8, 16);        / <summary>/ 获得8位的

97、MD5加密/ </summary>/ <param name="input"></param>/ <returns></returns>public static string GetMD5_8(string input)        return GetMD5_32(input).Substring(8, 8);        / <summary>/ 获得4位

98、的MD5加密/ </summary>/ <param name="input"></param>/ <returns></returns>public static string GetMD5_4(string input)        return GetMD5_32(input).Substring(8, 4);        public static string M

99、D5EncryptHash(String input)                    MD5 md5 = new MD5CryptoServiceProvider();/the GetBytes method returns byte array equavalent of a stringbyte res = md5.ComputeHash(Encoding.Default.GetBytes(input),

100、 0, input.Length);char temp = new charres.Length;/copy to a char array which can be passed to a String constructor            Array.Copy(res, temp, res.Length);/return the result as a stringreturn new String(temp);     &

101、#160;  5、 对文件添加MD5标签及验证 这种方式比较有趣，我也是最近才发现其中的奥妙，其实我们为了防止文件被修改，可以采用这种方式预先添加MD5码，然后在程序代码中进行验证，这样至少可以减少部分篡改的行为吧，因为只要文件有些少的修改，Md5码将会发生变化的，呵呵。 #region MD5签名验证 / <summary>/ 对给定文件路径的文件加上标签/ </summary>/ <param name="path">要加密的文件的路径</param>/ <returns>标签的值</returns>public static bool AddMD5(string path)        bool IsNeed = true;if (CheckMD5(path)     &#