clsaes.cs

AES 128/192位加密算法,可与C++加密算法共用

											/*d*/  {0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e},
											/*e*/  {0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf},
											/*f*/  {0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16} };

		}  // BuildSbox() 

		private void BuildInvSbox()
		{
			this.iSbox = new byte[16,16] {  // populate the iSbox matrix
											 /* 0     1     2     3     4     5     6     7     8     9     a     b     c     d     e     f */
											 /*0*/  {0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb},
											 /*1*/  {0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb},
											 /*2*/  {0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e},
											 /*3*/  {0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25},
											 /*4*/  {0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92},
											 /*5*/  {0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84},
											 /*6*/  {0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06},
											 /*7*/  {0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b},
											 /*8*/  {0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73},
											 /*9*/  {0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e},
											 /*a*/  {0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b},
											 /*b*/  {0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4},
											 /*c*/  {0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f},
											 /*d*/  {0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef},
											 /*e*/  {0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61},
											 /*f*/  {0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d} };

		}  // BuildInvSbox()

		private void BuildRcon()
		{
			this.Rcon = new byte[11,4] { {0x00, 0x00, 0x00, 0x00},  
								   {0x01, 0x00, 0x00, 0x00},
								   {0x02, 0x00, 0x00, 0x00},
								   {0x04, 0x00, 0x00, 0x00},
								   {0x08, 0x00, 0x00, 0x00},
								   {0x10, 0x00, 0x00, 0x00},
								   {0x20, 0x00, 0x00, 0x00},
								   {0x40, 0x00, 0x00, 0x00},
								   {0x80, 0x00, 0x00, 0x00},
								   {0x1b, 0x00, 0x00, 0x00},
								   {0x36, 0x00, 0x00, 0x00} };
		}  // BuildRcon()

		private void AddRoundKey(int round)
		{

			for (int r = 0; r < 4; ++r)
			{
				for (int c = 0; c < 4; ++c)
				{
					this.State[r,c] = (byte) ( (int)this.State[r,c] ^ (int)w[(round*4)+c,r] );
				}
			}
		}  // AddRoundKey()

		private void SubBytes()
		{
			for (int r = 0; r < 4; ++r)
			{
				for (int c = 0; c < 4; ++c)
				{
					this.State[r,c] = this.Sbox[ (this.State[r,c] >> 4), (this.State[r,c] & 0x0f) ];
				}
			}
		}  // SubBytes

		private void InvSubBytes()
		{
			for (int r = 0; r < 4; ++r)
			{
				for (int c = 0; c < 4; ++c)
				{
					this.State[r,c] = this.iSbox[ (this.State[r,c] >> 4), (this.State[r,c] & 0x0f) ];
				}
			}
		}  // InvSubBytes

		private void ShiftRows()
		{
			byte[,] temp = new byte[4,4];
			for (int r = 0; r < 4; ++r)  // copy State into temp[]
			{
				for (int c = 0; c < 4; ++c)
				{
					temp[r,c] = this.State[r,c];
				}
			}

			for (int r = 1; r < 4; ++r)  // shift temp into State
			{
				for (int c = 0; c < 4; ++c)
				{
					this.State[r,c] = temp[ r, (c + r) % Nb ];
				}
			}
		}  // ShiftRows()

		private void InvShiftRows()
		{
			byte[,] temp = new byte[4,4];
			for (int r = 0; r < 4; ++r)  // copy State into temp[]
			{
				for (int c = 0; c < 4; ++c)
				{
					temp[r,c] = this.State[r,c];
				}
			}
			for (int r = 1; r < 4; ++r)  // shift temp into State
			{
				for (int c = 0; c < 4; ++c)
				{
					this.State[r, (c + r) % Nb ] = temp[r,c];
				}
			}
		}  // InvShiftRows()

		private void MixColumns()
		{
			byte[,] temp = new byte[4,4];
			for (int r = 0; r < 4; ++r)  // copy State into temp[]
			{
				for (int c = 0; c < 4; ++c)
				{
					temp[r,c] = this.State[r,c];
				}
			}
        
			for (int c = 0; c < 4; ++c)
			{
				this.State[0,c] = (byte) ( (int)gfmultby02(temp[0,c]) ^ (int)gfmultby03(temp[1,c]) ^
					(int)gfmultby01(temp[2,c]) ^ (int)gfmultby01(temp[3,c]) );
				this.State[1,c] = (byte) ( (int)gfmultby01(temp[0,c]) ^ (int)gfmultby02(temp[1,c]) ^
					(int)gfmultby03(temp[2,c]) ^ (int)gfmultby01(temp[3,c]) );
				this.State[2,c] = (byte) ( (int)gfmultby01(temp[0,c]) ^ (int)gfmultby01(temp[1,c]) ^
					(int)gfmultby02(temp[2,c]) ^ (int)gfmultby03(temp[3,c]) );
				this.State[3,c] = (byte) ( (int)gfmultby03(temp[0,c]) ^ (int)gfmultby01(temp[1,c]) ^
					(int)gfmultby01(temp[2,c]) ^ (int)gfmultby02(temp[3,c]) );
			}
		}  // MixColumns

		private void InvMixColumns()
		{
			byte[,] temp = new byte[4,4];
			for (int r = 0; r < 4; ++r)  // copy State into temp[]
			{
				for (int c = 0; c < 4; ++c)
				{
					temp[r,c] = this.State[r,c];
				}
			}
        
			for (int c = 0; c < 4; ++c)
			{
				this.State[0,c] = (byte) ( (int)gfmultby0e(temp[0,c]) ^ (int)gfmultby0b(temp[1,c]) ^
					(int)gfmultby0d(temp[2,c]) ^ (int)gfmultby09(temp[3,c]) );
				this.State[1,c] = (byte) ( (int)gfmultby09(temp[0,c]) ^ (int)gfmultby0e(temp[1,c]) ^
					(int)gfmultby0b(temp[2,c]) ^ (int)gfmultby0d(temp[3,c]) );
				this.State[2,c] = (byte) ( (int)gfmultby0d(temp[0,c]) ^ (int)gfmultby09(temp[1,c]) ^
					(int)gfmultby0e(temp[2,c]) ^ (int)gfmultby0b(temp[3,c]) );
				this.State[3,c] = (byte) ( (int)gfmultby0b(temp[0,c]) ^ (int)gfmultby0d(temp[1,c]) ^
					(int)gfmultby09(temp[2,c]) ^ (int)gfmultby0e(temp[3,c]) );
			}
		}  // InvMixColumns

		private static byte gfmultby01(byte b)
		{
			return b;
		}

		private static byte gfmultby02(byte b)
		{
			if (b < 0x80)
				return (byte)(int)(b <<1);
			else
				return (byte)( (int)(b << 1) ^ (int)(0x1b) );
		}

		private static byte gfmultby03(byte b)
		{
			return (byte) ( (int)gfmultby02(b) ^ (int)b );
		}

		private static byte gfmultby09(byte b)
		{
			return (byte)( (int)gfmultby02(gfmultby02(gfmultby02(b))) ^
				(int)b );
		}

		private static byte gfmultby0b(byte b)
		{
			return (byte)( (int)gfmultby02(gfmultby02(gfmultby02(b))) ^
				(int)gfmultby02(b) ^
				(int)b );
		}

		private static byte gfmultby0d(byte b)
		{
			return (byte)( (int)gfmultby02(gfmultby02(gfmultby02(b))) ^
				(int)gfmultby02(gfmultby02(b)) ^
				(int)(b) );
		}

		private static byte gfmultby0e(byte b)
		{
			return (byte)( (int)gfmultby02(gfmultby02(gfmultby02(b))) ^
				(int)gfmultby02(gfmultby02(b)) ^
				(int)gfmultby02(b) );
		}

		private void KeyExpansion()
		{
			this.w = new byte[Nb * (Nr+1), 4];  // 4 columns of bytes corresponds to a word
    
			for (int row = 0; row < Nk; ++row)
			{
				this.w[row,0] = this.key[4*row];
				this.w[row,1] = this.key[4*row+1];
				this.w[row,2] = this.key[4*row+2];
				this.w[row,3] = this.key[4*row+3];
			}

			byte[] temp = new byte[4];

			for (int row = Nk; row < Nb * (Nr+1); ++row)
			{
				temp[0] = this.w[row-1,0]; temp[1] = this.w[row-1,1];
				temp[2] = this.w[row-1,2]; temp[3] = this.w[row-1,3];

				if (row % Nk == 0)  
				{
					temp = SubWord(RotWord(temp));
          
					temp[0] = (byte)( (int)temp[0] ^ (int)this.Rcon[row/Nk,0] );
					temp[1] = (byte)( (int)temp[1] ^ (int)this.Rcon[row/Nk,1] );
					temp[2] = (byte)( (int)temp[2] ^ (int)this.Rcon[row/Nk,2] );
					temp[3] = (byte)( (int)temp[3] ^ (int)this.Rcon[row/Nk,3] );
				}
				else if ( Nk > 6 && (row % Nk == 4) )  
				{
					temp = SubWord(temp);
				}
        
				// w[row] = w[row-Nk] xor temp
				this.w[row,0] = (byte) ( (int)this.w[row-Nk,0] ^ (int)temp[0] );
				this.w[row,1] = (byte) ( (int)this.w[row-Nk,1] ^ (int)temp[1] );
				this.w[row,2] = (byte) ( (int)this.w[row-Nk,2] ^ (int)temp[2] );
				this.w[row,3] = (byte) ( (int)this.w[row-Nk,3] ^ (int)temp[3] );
       
			}  // for loop
		}  // KeyExpansion()

		private byte[] SubWord(byte[] word)
		{
			byte[] result = new byte[4];
			result[0] = this.Sbox[ word[0] >> 4, word[0] & 0x0f ];
			result[1] = this.Sbox[ word[1] >> 4, word[1] & 0x0f ];
			result[2] = this.Sbox[ word[2] >> 4, word[2] & 0x0f ];
			result[3] = this.Sbox[ word[3] >> 4, word[3] & 0x0f ];
			return result;
		}

		private byte[] RotWord(byte[] word)
		{
			byte[] result = new byte[4];
			result[0] = word[1];
			result[1] = word[2];
			result[2] = word[3];
			result[3] = word[0];
			return result;
		}

		public  void Dump()
		{
			Console.WriteLine("Nb = " + Nb + " Nk = " + Nk + " Nr = " + Nr);
			Console.WriteLine("\nThe key is \n" + DumpKey() );
			Console.WriteLine("\nThe Sbox is \n" + DumpTwoByTwo(Sbox));
			Console.WriteLine("\nThe w array is \n" + DumpTwoByTwo(w));
			Console.WriteLine("\nThe State array is \n" + DumpTwoByTwo(State));
		}

		public string DumpKey()
		{
			string s = "";
			for (int i = 0; i < key.Length; ++i)
				s += key[i].ToString("x2") + " ";
			return s;
		}

		public string DumpTwoByTwo(byte[,] a)
		{
			string s ="";
			for (int r = 0; r < a.GetLength(0); ++r)
			{
				s += "["+r+"]" + " ";
				for (int c = 0; c < a.GetLength(1); ++c)
				{
					s += a[r,c].ToString("x2") + " " ;
				}
				s += "\n";
			}
			return s;
		}

		#endregion // AES Tables and Work Body

		#region Byte and String Conversions

		/// <summary>
		/// Converts a string to a byte array
		/// </summary>
		/// <param name="StrToConvert">the string to convert</param>
		private byte[] ConvertStringToByteArray(string StrToConvert)
		{
			return System.Text.ASCIIEncoding.ASCII.GetBytes(StrToConvert);
		}

		/// <summary>
		/// Converts a byte array to a string
		/// </summary>
		/// <param name="ByteToConvert"></param>
		/// <returns></returns>
		private string ConvertByteArrayToString(byte[] ByteToConvert)
		{
			string tempStr = "";
			for (int i=0; i<ByteToConvert.Length; i++)
			{
				// do not convert 0
				if (ByteToConvert[i] > 0)
					tempStr += System.Convert.ToChar(ByteToConvert[i]);
			}

			return tempStr;
		}

		#endregion // Byte and String Conversions

		#region Misc Functions

		/// <summary>
		/// Display an error message
		/// </summary>
		/// <param name="excep">the exception</param>
		/// <param name="FunctionName">the name of the function that caused the error</param>
		private void AES_ShowError(Exception excep, string FunctionName)
		{
			string errMsg = "";
			string nl = "\r\n";

			try
			{
				// build the error string
				errMsg += "An error has ocurred." + nl;
				errMsg += "Function: clsAES." + FunctionName.Trim() + nl;
				errMsg += "Source: " + excep.Source + nl;
				errMsg += "Error Description: " + nl + excep.Message;

				// show the message
				MessageBox.Show(errMsg, "AES Encryption", MessageBoxButtons.OK, MessageBoxIcon.Error);
			}
			catch
			{}
		}

		/// <summary>
		/// Returns the size of the array needed to meet BlockSize
		/// </summary>
		/// <param name="ArrayLen">the length of the current array</param>
		private int GetArraySize(int ArrayLen)
		{
			// if this is divisible by blocksize, return arraylen
			if ( (BlockSize % ArrayLen) == 0)
				return ArrayLen;

			// return the new array size
            return ( ((ArrayLen / BlockSize) + 1) * BlockSize);
		}

		#endregion // Misc Functions
	}
}