C#编写的Base64加密和解密类

/// <summary>/// Base64加密，解密方法/// </summary>/// <paramname="s">输入字符串</param>/// <paramname="c">true-加密,false-解密</param>static public string base64(string s, bool c){  if (c)  {    returnSystem.Convert.ToBase64String(System.Text.Encoding.Default.GetBytes(s));  }  else  {    try{  returnSystem.Text.Encoding.Default.GetString(System.Convert.FromBase64String(pwdString));}catch(Exception exp){  returnexp.Message;}  }}

using System;using System.Security.Cryptography; using System.Text;namespace DotNet.Utilities{  /// <summary>  /// Encrypt 的摘要说明。  /// </summary>  public class DEncrypt  {    /// <summary>    /// 构造方法    /// </summary>    public DEncrypt()     {     }     #region 使用 缺省密钥字符串 加密/解密string     /// <summary>    /// 使用缺省密钥字符串加密string    /// </summary>    /// <param name="original">明文</param>    /// <returns>密文</returns>    public static string Encrypt(string original)    {      return Encrypt(original,"sharejs.com");    }    /// <summary>    /// 使用缺省密钥字符串解密string    /// </summary>    /// <param name="original">密文</param>    /// <returns>明文</returns>    public static string Decrypt(string original)    {      return Decrypt(original,"sharejs.com",System.Text.Encoding.Default);    }     #endregion     #region 使用 给定密钥字符串 加密/解密string    /// <summary>    /// 使用给定密钥字符串加密string    /// </summary>    /// <param name="original">原始文字</param>    /// <param name="key">密钥</param>    /// <param name="encoding">字符编码方案</param>    /// <returns>密文</returns>    public static string Encrypt(string original, string key)     {       byte[] buff = System.Text.Encoding.Default.GetBytes(original);       byte[] kb = System.Text.Encoding.Default.GetBytes(key);      return Convert.ToBase64String(Encrypt(buff,kb));       }    /// <summary>    /// 使用给定密钥字符串解密string    /// </summary>    /// <param name="original">密文</param>    /// <param name="key">密钥</param>    /// <returns>明文</returns>    public static string Decrypt(string original, string key)    {      return Decrypt(original,key,System.Text.Encoding.Default);    }     /// <summary>    /// 使用给定密钥字符串解密string,返回指定编码方式明文    /// </summary>    /// <param name="encrypted">密文</param>    /// <param name="key">密钥</param>    /// <param name="encoding">字符编码方案</param>    /// <returns>明文</returns>    public static string Decrypt(string encrypted, string key,Encoding encoding)     {         byte[] buff = Convert.FromBase64String(encrypted);       byte[] kb = System.Text.Encoding.Default.GetBytes(key);      return encoding.GetString(Decrypt(buff,kb));       }     #endregion     #region 使用 缺省密钥字符串 加密/解密/byte[]    /// <summary>    /// 使用缺省密钥字符串解密byte[]    /// </summary>    /// <param name="encrypted">密文</param>    /// <param name="key">密钥</param>    /// <returns>明文</returns>    public static byte[] Decrypt(byte[] encrypted)     {       byte[] key = System.Text.Encoding.Default.GetBytes("sharejs.com");      return Decrypt(encrypted,key);      }    /// <summary>    /// 使用缺省密钥字符串加密    /// </summary>    /// <param name="original">原始数据</param>    /// <param name="key">密钥</param>    /// <returns>密文</returns>    public static byte[] Encrypt(byte[] original)     {       byte[] key = System.Text.Encoding.Default.GetBytes("sharejs.com");      return Encrypt(original,key);      }     #endregion    #region 使用 给定密钥 加密/解密/byte[]     /// <summary>    /// 生成MD5摘要    /// </summary>    /// <param name="original">数据源</param>    /// <returns>摘要</returns>    public static byte[] MakeMD5(byte[] original)    {      MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();       byte[] keyhash = hashmd5.ComputeHash(original);         hashmd5 = null;       return keyhash;    }    /// <summary>    /// 使用给定密钥加密    /// </summary>    /// <param name="original">明文</param>    /// <param name="key">密钥</param>    /// <returns>密文</returns>    public static byte[] Encrypt(byte[] original, byte[] key)     {       TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();         des.Key = MakeMD5(key);      des.Mode = CipherMode.ECB;          return des.CreateEncryptor().TransformFinalBlock(original, 0, original.Length);      }      /// <summary>    /// 使用给定密钥解密数据    /// </summary>    /// <param name="encrypted">密文</param>    /// <param name="key">密钥</param>    /// <returns>明文</returns>    public static byte[] Decrypt(byte[] encrypted, byte[] key)     {       TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();       des.Key = MakeMD5(key);        des.Mode = CipherMode.ECB;        return des.CreateDecryptor().TransformFinalBlock(encrypted, 0, encrypted.Length);    }       #endregion  }}

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;     }    } }