aes加密算法.cs

AES加密和解密源码！

using System;

namespace AES类库

{   /// <summary>
	/// Class1 的摘要说明。
	/// </summary>
	public class AES加密算法
	{
		public byte[,] State=new byte[4,4];
		public byte[,] Sbox =new byte[16,16];
		public byte[ ] key2 =new byte[16];         
		public byte[,] w    =new byte[44,4];
		public byte[ ] temp =new byte[4];
		public byte[,] Rcon =new byte[11,4];
		
		public AES加密算法(byte[]input,byte[]key,ref byte[]output)
		{
		   Sbox = new byte[16,16] {  
/*        0     1     2     3     4     5     6     7     8     9     a     b     c     d    e      f   */
/*0*/  {0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76},
/*1*/  {0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0},
/*2*/  {0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15},
/*3*/  {0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75},
/*4*/  {0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84},
/*5*/  {0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf},
/*6*/  {0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8},
/*7*/  {0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2},
/*8*/  {0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73},
/*9*/  {0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb},
/*a*/  {0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79},
/*b*/  {0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08},
/*c*/  {0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a},
/*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} };

			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} };

			key.CopyTo(key2,0);

			for (int i = 0; i <16; i++)
			{
				State[i % 4, i / 4] = input[i];
			}

			AddRoundKey(0);
          
			for (int round = 1; round <= 9; round++)  
			{
				SubBytes(); 
				ShiftRows();  
				MixColumns(); 
				AddRoundKey(round);
			}  

			SubBytes();
			ShiftRows();
			AddRoundKey(10);
            
			for (int i = 0; i < 16;i++)
			{
				output[i] = State[i % 4, i / 4];
			}

		   }		  
		
//**************************************加密的四个步骤**************************
		public void AddRoundKey(int round)
		{
			for (int i = 0; i < 4; i++)
			{
				for (int j = 0; j < 4; j++)
				{
					State[i,j] = (byte) ( (int)State[i,j] ^ (int)w[(4*round)+j,i] );
				}
			}

		}
		
		public void SubBytes()
		{
			for (int i = 0;i < 4; i++)
			{
				for (int j = 0; j < 4; j++)
				{
					State[i,j] = Sbox[ (State[i,j] >> 4), (State[i,j] & 0x0f) ];
				}
			}

		}
		
		public void ShiftRows()
		{  
			byte[,] transfer1 = new byte[4,4];

			for (int i= 0; i < 4; i++) 
			{
				for (int j= 0; j < 4;j++)
				{
					transfer1[i,j] = State[i,j];
				}
			}
            for (int m = 1; m < 4; m++) 
			{
				for (int n = 0; n < 4; n++)
				{
					State[m,n] = transfer1[ m, (m+n) % 4 ];
				}
			}

		}

		public void MixColumns()
		{
			byte[,] transfer2 = new byte[4,4];

			for (int i= 0; i < 4; i++)  
			{
				for (int j = 0; j < 4; j++)
				{
					transfer2[i,j] = State[i,j];
				}
			}
        
			for (int k= 0; k< 4; k++)
			{
				State[0,k] = (byte) ( FieldMult(2,transfer2[0,k]) ^ FieldMult(3,transfer2[1,k]) ^
					                  FieldMult(1,transfer2[2,k]) ^ FieldMult(1,transfer2[3,k]) );
				State[1,k] = (byte) ( FieldMult(1,transfer2[0,k]) ^ FieldMult(2,transfer2[1,k]) ^
					                  FieldMult(3,transfer2[2,k]) ^ FieldMult(1,transfer2[3,k]) );
				State[2,k] = (byte) ( FieldMult(1,transfer2[0,k]) ^ FieldMult(1,transfer2[1,k]) ^
					                  FieldMult(2,transfer2[2,k]) ^ FieldMult(3,transfer2[3,k]) );
				State[3,k] = (byte) ( FieldMult(3,transfer2[0,k]) ^ FieldMult(1,transfer2[1,k]) ^
					                  FieldMult(1,transfer2[2,k]) ^ FieldMult(2,transfer2[3,k]) );

			}
		}
//**********************************************************************	
		public int FieldMult(int i,byte j)
		{
			if     (i==1)      return (int)j;
			else if(i==2) 	
			{
				if (j<0x80)   return (int)(j<<1);
				else          return ((int)(j<<1)^(int)(0x1b));
			}
			else 
			{
				if (j<0x80)   return ((int)(j<<1)^(int)j);
				else          return ((int)(j<<1)^(int)(0x1b)^(int)j);
			}
		}

//****************************生成轮密钥*******************************
		public void KeyExpansion()
		{
			for (int i = 0; i < 4; i++)
			{
				w[i,0] = key2[4*i];
				w[i,1] = key2[4*i+1];
				w[i,2] = key2[4*i+2];
				w[i,3] = key2[4*i+3];
			}

			for (int i = 4; i < 44; i++)
			{
				temp[0] = w[i-1,0]; 
				temp[1] = w[i-1,1];
				temp[2] = w[i-1,2]; 
				temp[3] = w[i-1,3];

				if (i % 4 == 0)  
				{
					temp = SubWord(RotWord(temp));
          
					temp[0] = (byte)( (int)temp[0] ^ (int)Rcon[i/4,0] );
					temp[1] = (byte)( (int)temp[1] ^ (int)Rcon[i/4,1] );
					temp[2] = (byte)( (int)temp[2] ^ (int)Rcon[i/4,2] );
					temp[3] = (byte)( (int)temp[3] ^ (int)Rcon[i/4,3] );
				}

				w[i,0] = (byte) ( (int)w[i-4,0] ^ (int)temp[0] );
				w[i,1] = (byte) ( (int)w[i-4,1] ^ (int)temp[1] );
				w[i,2] = (byte) ( (int)w[i-4,2] ^ (int)temp[2] );
				w[i,3] = (byte) ( (int)w[i-4,3] ^ (int)temp[3] );
       
			} 
		} 

		public byte[] SubWord(byte[] word)
		{
			byte[] transfer3 = new byte[4];
			transfer3[0] = Sbox[ word[0] >> 4, word[0] & 0x0f ];
			transfer3[1] = Sbox[ word[1] >> 4, word[1] & 0x0f ];
			transfer3[2] = Sbox[ word[2] >> 4, word[2] & 0x0f ];
			transfer3[3] = Sbox[ word[3] >> 4, word[3] & 0x0f ];
			return   transfer3;
		}

		public byte[] RotWord(byte[] word)
		{
			byte[] transfer4 = new byte[4];
			transfer4[0] = word[1];
			transfer4[1] = word[2];
			transfer4[2] = word[3];
			transfer4[3] = word[0];
			return   transfer4;
		}
//************************************************************************
	}
	
}