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标题: TEA加密解密工具类 [打印本页]

作者: hnzrb 时间: 2018-7-21 15:39
标题: TEA加密解密工具类
/// <summary>
/// TEA加密解密工具类
/// </summary>
internal class TEAUtil
{
      /// <summary>
      /// 加密解密消息包的工具类.
      /// </summary>
      private static void code(byte[] In, int inOffset, int inPos, byte[] Out, int outOffset, int outPos, byte[] key)
      {
         if (outPos > 0)
         {
            for (int i = 0; i < 8; i++)
            {
                  In[outOffset + outPos + i] = (byte)(In[inOffset + inPos + i] ^ Out[outOffset + outPos + i - 8]);
            }
         }
         uint[] formattedKey = FormatKey(key);
         uint y = ConvertByteArrayToUInt(In, outOffset + outPos);
         uint z = ConvertByteArrayToUInt(In, outOffset + outPos + 4);
         uint sum = 0;
         uint delta = 0x9e3779b9;
         uint n = 16;
         while (n-- > 0)
         {
            sum += delta;
            y += ((z << 4) + formattedKey[0]) ^ (z + sum) ^ ((z >> 5) + formattedKey[1]);
            z += ((y << 4) + formattedKey[2]) ^ (y + sum) ^ ((y >> 5) + formattedKey[3]);
         }
         Array.Copy(ConvertUIntToByteArray(y), 0, Out, outOffset + outPos, 4);
         Array.Copy(ConvertUIntToByteArray(z), 0, Out, outOffset + outPos + 4, 4);
         if (inPos > 0)
         {
            for (int i = 0; i < 8; i++)
            {
                  Out[outOffset + outPos + i] = (byte)(Out[outOffset + outPos + i] ^ In[inOffset + inPos + i - 8]);
            }
         }
      }
      private static void decode(byte[] In, int inOffset, int inPos, byte[] Out, int outOffset, int outPos, byte[] key)
      {
         if (outPos > 0)
         {
            for (int i = 0; i < 8; i++)
            {
                  Out[outOffset + outPos + i] = (byte)(In[inOffset + inPos + i] ^ Out[outOffset + outPos + i - 8]);
            }
         }
         else
         {
            Array.Copy(In, inOffset, Out, outOffset, 8);
         }
         uint[] formattedKey = FormatKey(key);
         uint y = ConvertByteArrayToUInt(Out, outOffset + outPos);
         uint z = ConvertByteArrayToUInt(Out, outOffset + outPos + 4);
         uint sum = 0xE3779B90;
         uint delta = 0x9e3779b9;
         uint n = 16;
         while (n-- > 0)
         {
            z -= ((y << 4) + formattedKey[2]) ^ (y + sum) ^ ((y >> 5) + formattedKey[3]);
            y -= ((z << 4) + formattedKey[0]) ^ (z + sum) ^ ((z >> 5) + formattedKey[1]);
            sum -= delta;
         }
         Array.Copy(ConvertUIntToByteArray(y), 0, Out, outOffset + outPos, 4);
         Array.Copy(ConvertUIntToByteArray(z), 0, Out, outOffset + outPos + 4, 4);
      }
      /// <summary>
      /// 解密
      /// </summary>
      /// <param name="input">需要被解密的密文</param>
      /// <param name="key">密钥</param>
      /// <returns>Message 已解密的消息</returns>
      public static byte[] Decrypt(byte[] input, byte[] key)
      {
         return Decrypt(input, 0, input.Length, key);
      }
      /// <summary>
      /// 加密
      /// </summary>
      /// <param name="input">需要加密的明文</param>
      /// <param name="key">密钥</param>
      /// <returns>Message 密文</returns>
      public static byte[] Encrypt(byte[] input, byte[] key)
      {
         return Encrypt(input, 0, input.Length, key);
      }
      /// <summary>
      /// 解密
      /// </summary>
      /// <param name="In">密文</param>
      /// <param name="offset">密文开始的位置</param>
      /// <param name="len">密文长度</param>
      /// <param name="key">密钥</param>
      /// <returns>返回明文</returns>
      public static byte[] Decrypt(byte[] In, int offset, int len, byte[] key)
      {
         // 因为QQ消息加密之后至少是16字节，并且肯定是8的倍数，这里检查这种情况
         if ((len % 8 != 0) || (len < 16))
         {
            return null;
         }
         byte[] Out = new byte[len];
         for (int i = 0; i < len; i += 8)
         {
            decode(In, offset, i, Out, 0, i, key);
         }
         for (int i = 8; i < len; i++)
         {
            Out[i] = (byte)(Out[i] ^ In[offset + i - 8]);
         }
         int pos = Out[0] & 0x07;
         len = len - pos - 10;
         byte[] res = new byte[len];
         Array.Copy(Out, pos + 3, res, 0, len);
         return res;
      }
      /// <summary>
      /// 加密
      /// </summary>
      /// <param name="In">明文</param>
      /// <param name="offset">明文开始的位置</param>
      /// <param name="len">明文长度</param>
      /// <param name="key">密钥</param>
      /// <returns>返回密文</returns>
      public static byte[] Encrypt(byte[] In, int offset, int len, byte[] key)
      {
         Random rand = new Random();
         // 计算头部填充字节数
         int pos = (len + 10) % 8;
         if (pos != 0)
         {
            pos = 8 - pos;
         }
         byte[] plain = new byte[len + pos + 10];
         plain[0] = (byte)((rand.Next() & 0xF8) | pos);
         for (int i = 1; i < pos + 3; i++)
         {
            plain[i] = (byte)(rand.Next() & 0xFF);
         }
         Array.Copy(In, 0, plain, pos + 3, len);
         for (int i = pos + 3 + len; i < plain.Length; i++)
         {
            plain[i] = 0x0;
         }
         // 定义输出流
         byte[] outer = new byte[len + pos + 10];
         for (int i = 0; i < outer.Length; i += 8)
         {
            code(plain, 0, i, outer, 0, i, key);
         }
         return outer;
      }
      //格式化密钥
      private static uint[] FormatKey(byte[] key)
      {
         if (key.Length == 0)
         {
            throw new ArgumentException("Key must be between 1 and 16 characters in length");
         }
         byte[] refineKey = new byte[16];
         if (key.Length < 16)
         {
            Array.Copy(key, 0, refineKey, 0, key.Length);
            for (int k = key.Length; k < 16; k++)
            {
                  refineKey[k] = 0x20;
            }
         }
         else
         {
            Array.Copy(key, 0, refineKey, 0, 16);
         }
         uint[] formattedKey = new uint[4];
         int j = 0;
         for (int i = 0; i < refineKey.Length; i += 4)
         {
            formattedKey[j++] = ConvertByteArrayToUInt(refineKey, i);
         }
         return formattedKey;
      }
      private static byte[] ConvertUIntToByteArray(uint v)
      {
         byte[] result = new byte[4];
         result[0] = (byte)((v >> 24) & 0xFF);
         result[1] = (byte)((v >> 16) & 0xFF);
         result[2] = (byte)((v >> 8) & 0xFF);
         result[3] = (byte)((v >> 0) & 0xFF);
         return result;
      }
      private static uint ConvertByteArrayToUInt(byte[] v, int offset)
      {
         if (offset + 4 > v.Length)
         {
            return 0;
         }
         uint output;
         output = (uint)(v[offset] << 24);
         output |= (uint)(v[offset + 1] << 16);
         output |= (uint)(v[offset + 2] << 8);
         output |= (uint)(v[offset + 3] << 0);
         return output;
      }
}

作者: 薆要执著 时间: 2018-7-21 15:59
贴代码还是用代码标签贴吧

作者: a422880152 时间: 2018-7-22 10:07
已将很不错了

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