C# 加密或解密算法 Cryptography CRC32 MD5 BASE64

Cryptography、CRC32、MD5、BASE64的加密或解密算法和操作类

using System; using System.Collections.Generic; using System.Text; using System.Security; using System.Security.Cryptography; using System.Data; using System.IO; namespace SercurityLib { /**//// <summary> /// Cryptography 的摘要说明。 /// </summary> public class Cryptography { //加密KEY private static SymmetricAlgorithm key; static Cryptography() { key = new DESCryptoServiceProvider(); } public Cryptography(SymmetricAlgorithm inKey) { key = inKey; } /**//// <summary> /// 哈希字符串 /// </summary> /// <param name="pwd"></param> /// <returns></returns> public static string GetPWDHash(string pwd) { string ret = ""; byte[] bpwd = Encoding.ASCII.GetBytes(pwd.Trim()); byte[] edata; SHA256 sha = new SHA256Managed(); edata = sha.ComputeHash(bpwd); ret=Convert.ToBase64String(edata); return ret.Trim(); } /**//// <summary> /// 对字符串做对称加密返回加密后的数据 /// </summary> /// <param name="original"></param> /// <returns></returns> public static string GetEncrypt(string original) { return Convert.ToBase64String(Encrypt(original, key)); } /**//// <summary> /// 对字符串做对称解密返回解密后的数据 /// </summary> /// <param name="encrypt"></param> /// <returns></returns> public static string GetDecrypt(string encrypt) { return Decrypt(Convert.FromBase64String(encrypt), key); } public string BytesToString(byte[] bs) { StringBuilder sb = new StringBuilder(); foreach (byte b in bs) { sb.Append(b.ToString("000")); } return sb.ToString(); } public static byte[] StringToBytes(string s) { int bl = s.Length / 3; byte[] bs = new byte[bl]; for (int i = 0; i < bl; i++) { bs[i] = byte.Parse(s.Substring(3 * i, 3)); } return bs; } private static byte[] Encrypt(string PlainText, SymmetricAlgorithm key) { MemoryStream ms = new MemoryStream(); CryptoStream encStream = new CryptoStream(ms, key.CreateEncryptor(), CryptoStreamMode.Write); StreamWriter sw = new StreamWriter(encStream); sw.WriteLine(PlainText); sw.Close(); encStream.Close(); byte[] buffer = ms.ToArray(); ms.Close(); return buffer; } private static string Decrypt(byte[] CypherText, SymmetricAlgorithm key) { MemoryStream ms = new MemoryStream(CypherText); CryptoStream encStream = new CryptoStream(ms, key.CreateDecryptor(), CryptoStreamMode.Read); StreamReader sr = new StreamReader(encStream); string val = sr.ReadLine(); sr.Close(); encStream.Close(); ms.Close(); return val; } } /**//// <summary> /// CRC 效验 /// 快速检测算法 /// </summary> public class CRC32 { /**//// <summary> /// /// </summary> protected ulong[] crc32Table; /**//// <summary> /// 构造：初始化效验表 /// </summary> public CRC32() { const ulong ulPolynomial = 0xEDB88320; ulong dwCrc; crc32Table = new ulong[256]; int i, j; for (i = 0; i < 256; i++) { dwCrc = (ulong)i; for (j = 8; j > 0; j--) { if ((dwCrc & 1) == 1) dwCrc = (dwCrc >> 1) ^ ulPolynomial; else dwCrc >>= 1; } crc32Table[i] = dwCrc; } } /**//// <summary> /// 字节数组效验 /// </summary> /// <param name="buffer">ref 字节数组</param> /// <returns></returns> public ulong ByteCRC(ref byte[] buffer) { ulong ulCRC = 0xffffffff; ulong len; len = (ulong)buffer.Length; for (ulong buffptr = 0; buffptr < len; buffptr++) { ulong tabPtr = ulCRC & 0xFF; tabPtr = tabPtr ^ buffer[buffptr]; ulCRC = ulCRC >> 8; ulCRC = ulCRC ^ crc32Table[tabPtr]; } return ulCRC ^ 0xffffffff; } /**//// <summary> /// 字符串效验 /// </summary> /// <param name="sInputString">字符串</param> /// <returns></returns> public ulong StringCRC(string sInputString) { byte[] buffer = Encoding.Default.GetBytes(sInputString); return ByteCRC(ref buffer); } /**//// <summary> /// 文件效验 /// </summary> /// <param name="sInputFilename">输入文件</param> /// <returns></returns> public ulong FileCRC(string sInputFilename) { FileStream inFile = new System.IO.FileStream(sInputFilename, System.IO.FileMode.Open, System.IO.FileAccess.Read); byte[] bInput = new byte[inFile.Length]; inFile.Read(bInput, 0, bInput.Length); inFile.Close(); return ByteCRC(ref bInput); } } /**//// <summary> /// MD5 无逆向编码 /// 获取唯一特征串，可用于密码加密 /// (无法还原) /// </summary> public class MD5 { /**//// <summary> /// /// </summary> public MD5() { } /**//// <summary> /// 获取字符串的特征串 /// </summary> /// <param name="sInputString">输入文本</param> /// <returns></returns> public static string HashString(string sInputString) { System.Security.Cryptography.MD5 md5 = System.Security.Cryptography.MD5.Create(); string encoded = BitConverter.ToString(md5.ComputeHash(Encoding.Default.GetBytes(sInputString))).Replace("-", ""); return encoded; } /**//// <summary> /// 获取文件的特征串 /// </summary> /// <param name="sInputFilename">输入文件</param> /// <returns></returns> public string HashFile(string sInputFilename) { System.Security.Cryptography.MD5 md5 = System.Security.Cryptography.MD5.Create(); FileStream inFile = new System.IO.FileStream(sInputFilename, System.IO.FileMode.Open, System.IO.FileAccess.Read); byte[] bInput = new byte[inFile.Length]; inFile.Read(bInput, 0, bInput.Length); inFile.Close(); string encoded = BitConverter.ToString(md5.ComputeHash(bInput)).Replace("-", ""); return encoded; } } /**//// <summary> /// Base64 UUEncoded 编码 /// 将二进制编码为ASCII文本，用于网络传输 /// (可还原) /// </summary> public class BASE64 { /**//// <summary> /// /// </summary> public BASE64() { } /**//// <summary> /// 解码字符串 /// </summary> /// <param name="sInputString">输入文本</param> /// <returns></returns> public string DecryptString(string sInputString) { char[] sInput = sInputString.ToCharArray(); try { byte[] bOutput = System.Convert.FromBase64String(sInputString); return Encoding.Default.GetString(bOutput); } catch (System.ArgumentNullException) { //base 64 字符数组为null return ""; } catch (System.FormatException) { //长度错误，无法整除4 return ""; } } /**//// <summary> /// 编码字符串 /// </summary> /// <param name="sInputString">输入文本</param> /// <returns></returns> public string EncryptString(string sInputString) { byte[] bInput = Encoding.Default.GetBytes(sInputString); try { return System.Convert.ToBase64String(bInput, 0, bInput.Length); } catch (System.ArgumentNullException) { //二进制数组为NULL. return ""; } catch (System.ArgumentOutOfRangeException) { //长度不够 return ""; } } /**//// <summary> /// 解码文件 /// </summary> /// <param name="sInputFilename">输入文件</param> /// <param name="sOutputFilename">输出文件</param> public void DecryptFile(string sInputFilename, string sOutputFilename) { System.IO.StreamReader inFile; char[] base64CharArray; try { inFile = new System.IO.StreamReader(sInputFilename, System.Text.Encoding.ASCII); base64CharArray = new char[inFile.BaseStream.Length]; inFile.Read(base64CharArray, 0, (int)inFile.BaseStream.Length); inFile.Close(); } catch {//(System.Exception exp) { return; } // 转换Base64 UUEncoded为二进制输出 byte[] binaryData; try { binaryData = System.Convert.FromBase64CharArray(base64CharArray, 0, base64CharArray.Length); } catch (System.ArgumentNullException) { //base 64 字符数组为null return; } catch (System.FormatException) { //长度错误，无法整除4 return; } // 写输出数据 System.IO.FileStream outFile; try { outFile = new System.IO.FileStream(sOutputFilename, System.IO.FileMode.Create, System.IO.FileAccess.Write); outFile.Write(binaryData, 0, binaryData.Length); outFile.Close(); } catch {// (System.Exception exp) { //流错误 } } /**//// <summary> /// 编码文件 /// </summary> /// <param name="sInputFilename">输入文件</param> /// <param name="sOutputFilename">输出文件</param> public void EncryptFile(string sInputFilename, string sOutputFilename) { System.IO.FileStream inFile; byte[] binaryData; try { inFile = new System.IO.FileStream(sInputFilename, System.IO.FileMode.Open, System.IO.FileAccess.Read); binaryData = new Byte[inFile.Length]; long bytesRead = inFile.Read(binaryData, 0, (int)inFile.Length); inFile.Close(); } catch { //(System.Exception exp) { return; } // 转换二进制输入为Base64 UUEncoded输出 // 每3个字节在源数据里作为4个字节 long arrayLength = (long)((4.0d / 3.0d) * binaryData.Length); // 如果无法整除4 if (arrayLength % 4 != 0) { arrayLength += 4 - arrayLength % 4; } char[] base64CharArray = new char[arrayLength]; try { System.Convert.ToBase64CharArray(binaryData, 0, binaryData.Length, base64CharArray, 0); } catch (System.ArgumentNullException) { //二进制数组为NULL. return; } catch (System.ArgumentOutOfRangeException) { //长度不够 return; } // 写UUEncoded数据到文件内 System.IO.StreamWriter outFile; try { outFile = new System.IO.StreamWriter(sOutputFilename, false, System.Text.Encoding.ASCII); outFile.Write(base64CharArray); outFile.Close(); } catch {// (System.Exception exp) { //文件流出错 } } } }

源：http://blog.youkuaiyun.com/beasyer/archive/2007/06/20/1660103.aspx