using System; using System.Collections.Generic; using System.Text; using System.Security.Cryptography; using System.IO; namespace Ecan.Crypt { public class EcanCryptography { /*MD5是message-digest algorithm 5(信息-摘要算法)的缩写, * 被广泛用于加密和解密技术上,它可以说是文件的“数字指纹”。 * 任何一个文件,无论是可执行程序、图像文件、临时文件或者其他任何类型的文件, * 也不管它体积多大,都有且只有一个独一无二的MD5信息值,并且如果这个文件被修改过, * 它的MD5值也将随之改变。因此,我们可以通过对比同一文件的MD5值, * 来校验这个文件是否被“篡改”过。*/ /// <summary> /// MD5加密函数 /// </summary> /// <param name="str">要加密的字符串</param> /// <returns>加密后的字符串</returns> /// public string md5_Encode(string str) { MD5 m = new MD5CryptoServiceProvider(); byte[] data = Encoding.Default.GetBytes(str); byte[] result = m.ComputeHash(data); string ret1 = ""; try { for (int j = 0; j < result.Length; j++) { ret1 += result[j].ToString("x").PadLeft(2, '0'); } return ret1; } catch { return str; } } /// <summary> /// 简单加密函数 /// </summary> /// <param name="str">要加密的字符串</param> /// <returns>返回加密后的字符串</returns> /// public static string simple_Encode(string str) { string s = ""; try { for (int i = 0; i < str.Length; i++) { s += (char)(str[i] + 10 - 1 * 2); } return s; } catch { return str; } } /// <summary> /// 简单解密函数 /// </summary> /// <param name="str">要解密的字符串</param> /// <returns>返回解密后的字符串</returns> /// public static string simple_Decode(string str) { string s = ""; try { for (int i = 0; i < str.Length; i++) { s += (char)(str[i] - 10 + 1 * 2); } return s; } catch { return str; } } //默认密钥向量 private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; /// <summary> /// 对称加密法加密函数 /// </summary> /// <param name="encryptString">待加密的字符串</param> /// <param name="encryptKey">加密密钥,要求为8位</param> /// <returns>加密成功返回加密后的字符串,失败返回源串</returns> public static string symmetry_Encode(string encryptString, string encryptKey) { try { byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8)); byte[] rgbIV = Keys; byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString); DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider(); MemoryStream mStream = new MemoryStream(); CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write); cStream.Write(inputByteArray, 0, inputByteArray.Length); cStream.FlushFinalBlock(); return Convert.ToBase64String(mStream.ToArray()); } catch { return encryptString; } } /// <summary> /// 对称加密法解密函数 /// </summary> /// <param name="decryptString">待解密的字符串</param> /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param> /// <returns>解密成功返回解密后的字符串,失败返源串</returns> public static string symmetry_Decode(string decryptString, string decryptKey) { try { byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey); byte[] rgbIV = Keys; byte[] inputByteArray = Convert.FromBase64String(decryptString); DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider(); MemoryStream mStream = new MemoryStream(); CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write); cStream.Write(inputByteArray, 0, inputByteArray.Length); cStream.FlushFinalBlock(); return Encoding.UTF8.GetString(mStream.ToArray()); } catch { return decryptString; } } } }