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;/ / 使用默认加密/ / / public static string DesEncrypt(string strText) try return DesEncrypt(strText, DEFAULT_ENCRYPT_KEY); catch return ; / / 使用默认解密/ / / public static string DesDecrypt(string s

4、trText) try return DesDecrypt(strText, DEFAULT_ENCRYPT_KEY); catch return ; / / Encrypt the string / Attention:key must be 8 bits / / string/ key/ public static string DesEncrypt(string strText, string strEncrKey) byte byKey = null;byte IV = 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF ; byKey = E

5、ncoding.UTF8.GetBytes(strEncrKey.Substring(0, 8); DESCryptoServiceProvider des = new DESCryptoServiceProvider();byte inputByteArray = Encoding.UTF8.GetBytes(strText); MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write);

6、 cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock();return Convert.ToBase64String(ms.ToArray(); / / Decrypt string / Attention:key must be 8 bits / / Decrypt string/ key/ output stringpublic static string DesDecrypt(string strText, string sDecrKey) byte byKey = null;byte IV = 0

7、x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF ;byte inputByteArray = new BytestrText.Length; byKey = Encoding.UTF8.GetBytes(sDecrKey.Substring(0, 8); DESCryptoServiceProvider des = new DESCryptoServiceProvider(); inputByteArray = Convert.FromBase64String(strText); MemoryStream ms = new MemoryStream(

8、); CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); Encoding encoding = new UTF8Encoding();return encoding.GetString(ms.ToArray(); / / Encrypt files / Attention:key must be 8 bits

9、 / / Encrypt file path/ output file/ keypublic static void DesEncrypt(string m_InFilePath, string m_OutFilePath, string strEncrKey) byte byKey = null;byte IV = 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF ; byKey = Encoding.UTF8.GetBytes(strEncrKey.Substring(0, 8); FileStream fin = new FileStream(

10、m_InFilePath, FileMode.Open, FileAccess.Read); FileStream fout = new FileStream(m_OutFilePath, FileMode.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

11、 the total number of bytes written. 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(); CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(byKey, IV), CryptoSt

12、reamMode.Write);/Read from the input file, then encrypt and write to the output file. while (rdlen totlen) len = fin.Read(bin, 0, 100); encStream.Write(bin, 0, len); rdlen = rdlen + len; encStream.Close(); fout.Close(); fin.Close(); / / Decrypt files / Attention:key must be 8 bits / / Decrypt filepa

13、th/ output filepath/ keypublic 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.UTF8.GetBytes(sDecrKey.Substring(0, 8); FileStream fin = new FileStream(m_InFilePath, FileMo

14、de.Open, FileAccess.Read); FileStream fout = new FileStream(m_OutFilePath, FileMode.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

15、 bytes written. 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(); CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write);/Rea

16、d from the input file, then encrypt and write to the output file. while (rdlen totlen) len = fin.Read(bin, 0, 100); encStream.Write(bin, 0, len); rdlen = rdlen + len; encStream.Close(); fout.Close(); 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 priva

17、te static readonly string Default_AES_Key = #kim123;private static byte Keys = 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D, 0x79,0x53,0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F ;/ / 对称加密算法AES RijndaelManaged加密(RijndaelManaged（AES）算法是块式加密算法)/ / 待加密字符串/ 加密结果字符串public static string AES_Encrypt(string encryp

18、tString) return AES_Encrypt(encryptString, Default_AES_Key); / / 对称加密算法AES RijndaelManaged加密(RijndaelManaged（AES）算法是块式加密算法)/ / 待加密字符串/ 加密密钥，须半角字符/ 加密结果字符串public static string AES_Encrypt(string encryptString, string encryptKey) encryptKey = GetSubString(encryptKey, 32, ); encryptKey = encryptKey.Pad

19、Right(32, ); RijndaelManaged rijndaelProvider = new RijndaelManaged(); rijndaelProvider.Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 32); rijndaelProvider.IV = Keys; ICryptoTransform rijndaelEncrypt = rijndaelProvider.CreateEncryptor();byte inputData = Encoding.UTF8.GetBytes(encryptString);b

20、yte encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData, 0, inputData.Length);return Convert.ToBase64String(encryptedData); / / 对称加密算法AES RijndaelManaged解密字符串/ / 待解密的字符串/ 解密成功返回解密后的字符串,失败返源串public static string AES_Decrypt(string decryptString) return AES_Decrypt(decryptString, Default_AES

21、_Key); / / 对称加密算法AES RijndaelManaged解密字符串/ / 待解密的字符串/ 解密密钥,和加密密钥相同/ 解密成功返回解密后的字符串,失败返回空public static string AES_Decrypt(string decryptString, string decryptKey) try decryptKey = GetSubString(decryptKey, 32, ); decryptKey = decryptKey.PadRight(32, ); RijndaelManaged rijndaelProvider = new RijndaelMan

22、aged(); rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey); rijndaelProvider.IV = Keys; ICryptoTransform rijndaelDecrypt = rijndaelProvider.CreateDecryptor();byte inputData = Convert.FromBase64String(decryptString);byte decryptedData = rijndaelDecrypt.TransformFinalBlock(inputData, 0, inputDa

23、ta.Length);return Encoding.UTF8.GetString(decryptedData); catch return string.Empty; / / 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/ / 源字符串/ 所取字符串字节长度/ 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.)/ 某字符串的一部分private static string GetSubString(string sourceString, int length, string tailString) return GetSubString(sourceString,

24、 0, length, tailString); / / 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/ / 源字符串/ 索引位置，以0开始/ 所取字符串字节长度/ 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.)/ 某字符串的一部分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 - u9fa5, 日文

25、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+) /当截取的起始位置超出字段串长度时if (startIndex = sourceString.Length) return string.Empty; else return sourceString.Substring(startI

26、ndex, (length + startIndex) sourceString.Length) ? (sourceString.Length - startIndex) : length); /中文字符，如中国人民abcd123if (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 + length) endIndex = length + startIndex; else /当不在有效范围内时,只取到字符串的结尾 lengt

27、h = bytesSource.Length - startIndex; tailString = ; int anResultFlag = new intlength;int nFlag = 0;/字节大于127为双字节字符for (int i = startIndex; i 127) nFlag+;if (nFlag = 3) nFlag = 1; else nFlag = 0; anResultFlagi = nFlag; /最后一个字节为双字节字符的一半if (bytesSourceendIndex - 1 127) & (anResultFlaglength - 1 = 1) len

28、gth = length + 1; byte bsResult = new bytelength; Array.Copy(bytesSource, startIndex, bsResult, 0, length); myResult = Encoding.Default.GetString(bsResult); myResult = myResult + tailString;return myResult; return string.Empty; / / 加密文件流/ / / public static CryptoStream AES_EncryptStrream(FileStream

29、fs, string decryptKey) decryptKey = GetSubString(decryptKey, 32, ); decryptKey = decryptKey.PadRight(32, ); RijndaelManaged rijndaelProvider = new RijndaelManaged(); rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey); rijndaelProvider.IV = Keys; ICryptoTransform encrypto = rijndaelProvider.Cr

30、eateEncryptor(); CryptoStream cytptostreamEncr = new CryptoStream(fs, encrypto, CryptoStreamMode.Write);return cytptostreamEncr; / / 解密文件流/ / / public static CryptoStream AES_DecryptStream(FileStream fs, string decryptKey) decryptKey = GetSubString(decryptKey, 32, ); decryptKey = decryptKey.PadRight

31、(32, ); RijndaelManaged rijndaelProvider = new RijndaelManaged(); rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey); rijndaelProvider.IV = Keys; ICryptoTransform Decrypto = rijndaelProvider.CreateDecryptor(); CryptoStream cytptostreamDecr = new CryptoStream(fs, Decrypto, CryptoStreamMode.Rea

32、d);return cytptostreamDecr; / / 对指定文件加密/ / / / public static bool AES_EncryptFile(string InputFile, string OutputFile) try string decryptKey = ; FileStream fr = new FileStream(InputFile, FileMode.Open); FileStream fren = new FileStream(OutputFile, FileMode.Create); CryptoStream Enfr = AES_EncryptStr

33、ream(fren, decryptKey);byte bytearrayinput = new bytefr.Length; fr.Read(bytearrayinput, 0, bytearrayinput.Length); Enfr.Write(bytearrayinput, 0, bytearrayinput.Length); Enfr.Close(); fr.Close(); fren.Close(); catch /文件异常return false; return true; / / 对指定的文件解压缩/ / / / public static bool AES_DecryptFi

34、le(string InputFile, string OutputFile) try string decryptKey = ; FileStream fr = new FileStream(InputFile, FileMode.Open); FileStream frde = new FileStream(OutputFile, FileMode.Create); CryptoStream Defr = AES_DecryptStream(fr, decryptKey);byte bytearrayoutput = new byte1024;int m_count = 0;do m_co

35、unt = Defr.Read(bytearrayoutput, 0, bytearrayoutput.Length); frde.Write(bytearrayoutput, 0, m_count);if (m_count bytearrayoutput.Length)break; while (true); Defr.Close(); fr.Close(); frde.Close(); catch /文件异常return false; return true; #endregion 3、 Base64加密解密算法 #region Base64加密解密 / / Base64是一種使用64基的

36、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，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/ / / public static string Base64Encrypt(string str) byte encbuff = System.Text.Encoding.UTF8.GetBytes(str);return Convert.ToBase64String(encbuff); / / Base64解

37、密/ / / public static string Base64Decrypt(string str) byte decbuff = 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。 / / 获得32位的MD5加密/ / / publi

38、c static string GetMD5_32(string input) System.Security.Cryptography.MD5 md5 = System.Security.Cryptography.MD5.Create();byte data = md5.ComputeHash(System.Text.Encoding.Default.GetBytes(input); StringBuilder sb = new StringBuilder();for (int i = 0; i data.Length; i+) sb.Append(datai.ToString(x2); r

39、eturn sb.ToString(); / / 获得16位的MD5加密/ / / public static string GetMD5_16(string input) return GetMD5_32(input).Substring(8, 16); / / 获得8位的MD5加密/ / / public static string GetMD5_8(string input) return GetMD5_32(input).Substring(8, 8); / / 获得4位的MD5加密/ / / public static string GetMD5_4(string input) return GetMD5_32(input).Substring(8, 4); public static string MD5EncryptHash(String input) MD5 md5 = new MD5CryptoServiceProvider();/the GetBytes method returns byte array equavalent of a stringbyte res = md