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AES加解密算法C实现

一、算法简介

AES是一个分组密码，属于对称密码范畴，AES算法的模块在对称密码领域特别是分组密码领域常有使用。

二、算法流程

AES加密算法涉及4种操作：字节替代（SubBytes）、行移位（ShiftRows）、列混淆（MixColumns）和轮密钥加（AddRoundKey）。

加解密中每轮的密钥分别由种子密钥经过密钥扩展算法得到。

算法中16字节的明文、密文和轮子密钥都以一个4x4的矩阵表示。

流程图：

左边加密、右边解密

具体过程：

https://www.cnblogs.com/luop/p/4334160.html

https://www.cnblogs.com/OneFri/p/5924605.html

AES加密算法动画：

https://coolshell.cn/articles/3161.html

 

加密过程：

///////////加密函数///////////////////////////
unsigned char* AES::Cipher(unsigned char* input)
{
	unsigned char state[4][4];
	int i,r,c;
////将数组转换为矩阵///////////////////
	for(r=0; r<4; r++)
	{
		for(c=0; c<4 ;c++)
		{
			state[r][c] = input[c*4+r];
		}
	}

	AddRoundKey(state,w[0]);    ///////////////子密钥相加///////////////////
    
	for(i=1;i<=9;i++){
    	SubBytes(state);
    	ShiftRows(state);
    	MixColumns(state);
    	AddRoundKey(state,w[i]);
	} 
    SubBytes(state);
    ShiftRows(state);
    AddRoundKey(state,w[i]);
    
	for(r=0; r<4; r++)
	{
		for(c=0; c<4 ;c++)
		{
			input[c*4+r] = state[r][c];
		}
	}

	return input;
}

1.SubBytes：字节代替

通过S盒完成一个字节到另外一个字节的映射。

代码实现：

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

//////////////////AES类的析构函数////////////////////////
	unsigned char invsBox[256] = 
	{ /*  0    1    2    3    4    5    6    7    8    9    a    b    c    d    e    f  */  
		0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38,0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb, /*0*/ 
		0x7c,0xe3,0x39,0x82,0x9b,0x2f,0xff,0x87,0x34,0x8e,0x43,0x44,0xc4,0xde,0xe9,0xcb, /*1*/
		0x54,0x7b,0x94,0x32,0xa6,0xc2,0x23,0x3d,0xee,0x4c,0x95,0x0b,0x42,0xfa,0xc3,0x4e, /*2*/ 
		0x08,0x2e,0xa1,0x66,0x28,0xd9,0x24,0xb2,0x76,0x5b,0xa2,0x49,0x6d,0x8b,0xd1,0x25, /*3*/ 
		0x72,0xf8,0xf6,0x64,0x86,0x68,0x98,0x16,0xd4,0xa4,0x5c,0xcc,0x5d,0x65,0xb6,0x92, /*4*/ 
		0x6c,0x70,0x48,0x50,0xfd,0xed,0xb9,0xda,0x5e,0x15,0x46,0x57,0xa7,0x8d,0x9d,0x84, /*5*/ 
		0x90,0xd8,0xab,0x00,0x8c,0xbc,0xd3,0x0a,0xf7,0xe4,0x58,0x05,0xb8,0xb3,0x45,0x06, /*6*/ 
		0xd0,0x2c,0x1e,0x8f,0xca,0x3f,0x0f,0x02,0xc1,0xaf,0xbd,0x03,0x01,0x13,0x8a,0x6b, /*7*/
		0x3a,0x91,0x11,0x41,0x4f,0x67,0xdc,0xea,0x97,0xf2,0xcf,0xce,0xf0,0xb4,0xe6,0x73, /*8*/ 
		0x96,0xac,0x74,0x22,0xe7,0xad,0x35,0x85,0xe2,0xf9,0x37,0xe8,0x1c,0x75,0xdf,0x6e, /*9*/
		0x47,0xf1,0x1a,0x71,0x1d,0x29,0xc5,0x89,0x6f,0xb7,0x62,0x0e,0xaa,0x18,0xbe,0x1b, /*a*/
		0xfc,0x56,0x3e,0x4b,0xc6,0xd2,0x79,0x20,0x9a,0xdb,0xc0,0xfe,0x78,0xcd,0x5a,0xf4, /*b*/ 
		0x1f,0xdd,0xa8,0x33,0x88,0x07,0xc7,0x31,0xb1,0x12,0x10,0x59,0x27,0x80,0xec,0x5f, /*c*/ 
		0x60,0x51,0x7f,0xa9,0x19,0xb5,0x4a,0x0d,0x2d,0xe5,0x7a,0x9f,0x93,0xc9,0x9c,0xef, /*d*/ 
		0xa0,0xe0,0x3b,0x4d,0xae,0x2a,0xf5,0xb0,0xc8,0xeb,0xbb,0x3c,0x83,0x53,0x99,0x61, /*e*/ 
		0x17,0x2b,0x04,0x7e,0xba,0x77,0xd6,0x26,0xe1,0x69,0x14,0x63,0x55,0x21,0x0c,0x7d  /*f*/
	}; 
	memcpy(Sbox, sBox, 256);
	memcpy(InvSbox, invsBox, 256);
	KeyExpansion(key, w);
}
///////////////字节替换//////////////////////
void AES::SubBytes(unsigned char state[][4])
{
	int r,c;
	for(r=0; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			state[r][c] = Sbox[state[r][c]];
		}
	}
}

 2.ShiftRows：行位移

  是一个4x4的矩阵内部字节之间的置换，用于提供算法的扩散性。

代码实现：

/////////////////////行位移//////////////////
void AES::ShiftRows(unsigned char state[][4])
{
	unsigned char t[4];
	int r,c;
	for(r=1; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			t[c] = state[r][(c+r)%4];
		}
		for(c=0; c<4; c++)
		{
			state[r][c] = t[c];
		}
	}
}

3.MixCloumns: 列混淆

  利用GF(28)域上算术特性的一个代替，同样用于提供算法的扩散性。

////////////////伽罗华域内的两个字符做乘法运算///////////////
unsigned char AES::FFmul(unsigned char a, unsigned char b)
{
	unsigned char bw[4];
	unsigned char res=0;
	int i;
	bw[0] = b;
	for(i=1; i<4; i++)
	{
		bw[i] = bw[i-1]<<1;
		if(bw[i-1]&0x80)
		{
			bw[i]^=0x1b;
		}
	}
	for(i=0; i<4; i++)
	{
		if((a>>i)&0x01)
		{
			res ^= bw[i];
		}
	}
	return res;
}

/////////////////////列混合///////////////////
void AES::MixColumns(unsigned char state[][4])
{
	unsigned char t[4];
	int r,c;
	for(c=0; c< 4; c++)
	{
		for(r=0; r<4; r++)
		{
			t[r] = state[r][c];
		}
		for(r=0; r<4; r++)
		{
			state[r][c] = FFmul(0x02, t[r])
						^ FFmul(0x03, t[(r+1)%4])
						^ FFmul(0x01, t[(r+2)%4])
						^ FFmul(0x01, t[(r+3)%4]);
		}
	}
}

4.AddRoundKey： 轮秘钥加

其依据的原理是“任何数和自身的异或结果为0”。加密过程中，每轮的输入与轮子密钥异或一次；因此，解密时再异或上该轮的轮子密钥即可恢复。

代码实现：

////////////////////////密钥扩展///////////////////////////
void AES::KeyExpansion(unsigned char* key, unsigned char w[][4][4])
{
	int i,j,r,c;
	unsigned char rc[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36};
	for(r=0; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			w[0][r][c] = key[r+c*4];
		}
	}
	for(i=1; i<=10; i++)
	{
		for(j=0; j<4; j++)
		{
			unsigned char t[4];
			for(r=0; r<4; r++)
			{
				t[r] = j ? w[i][r][j-1] : w[i-1][r][3];
			}
			if(j == 0)
			{
				unsigned char temp = t[0];
				for(r=0; r<3; r++)
				{
					t[r] = Sbox[t[(r+1)%4]];
				}
				t[3] = Sbox[temp];
				t[0] ^= rc[i-1];
			}
			for(r=0; r<4; r++)
			{
				w[i][r][j] = w[i-1][r][j] ^ t[r];
			}
		}
	}
}
//////////////////子密钥相加/////////////////////
void AES::AddRoundKey(unsigned char state[][4], unsigned char k[][4])
{
	int r,c;
	for(c=0; c<4; c++)
	{
		for(r=0; r<4; r++)
		{
			state[r][c] ^= k[r][c];
		}
	}
}

解密函数

//////////////////////解密函数/////////////////////////
unsigned char* AES::InvCipher(unsigned char* input)
{
	unsigned char state[4][4];
	int i,r,c;

	for(r=0; r<4; r++)
	{
		for(c=0; c<4 ;c++)
		{
			state[r][c] = input[c*4+r];
		}
	}

	AddRoundKey(state, w[10]);
    InvShiftRows(state); 
    InvSubBytes(state); 
    
     for(i=9;i>=1;i--){
     	AddRoundKey(state,w[i]);
     	InvMixColumns(state);
     	InvShiftRows(state);
     	InvSubBytes(state);
     	
	 }
     
    AddRoundKey(state,w[i]);
     
	for(r=0; r<4; r++)
	{
		for(c=0; c<4 ;c++)
		{
			input[c*4+r] = state[r][c];
		}
	}

	return input;
}

 1.InvSubBytes：字节代替

/////////////////字节替换的逆运算////////////////////
void AES::InvSubBytes(unsigned char state[][4])
{
	int r,c;
	for(r=0; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			state[r][c] = InvSbox[state[r][c]];
		}
	}
}

 2.InvShiftRows：行位移

////////////////////行位移的逆运算///////////////////
void AES::InvShiftRows(unsigned char state[][4])
{
	unsigned char t[4];
	int r,c;
	for(r=1; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			t[c] = state[r][(c-r+4)%4];
		}
		for(c=0; c<4; c++)
		{
			state[r][c] = t[c];
		}
	}
}

 3.InvMixCloumns: 列混淆

///////////////////列混合的逆运算///////////////
void AES::InvMixColumns(unsigned char state[][4])
{
	unsigned char t[4];
	int r,c;
	for(c=0; c< 4; c++)
	{
		for(r=0; r<4; r++)
		{
			t[r] = state[r][c];
		}
		for(r=0; r<4; r++)
		{
			state[r][c] = FFmul(0x0e, t[r])
						^ FFmul(0x0b, t[(r+1)%4])
						^ FFmul(0x0d, t[(r+2)%4])
						^ FFmul(0x09, t[(r+3)%4]);
		}
	}
}

 4.AddRoundKey： 轮秘钥加 同上

三、完整代码

AES.cpp

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

//////////////////AES类的析构函数////////////////////////
	unsigned char invsBox[256] = 
	{ /*  0    1    2    3    4    5    6    7    8    9    a    b    c    d    e    f  */  
		0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38,0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb, /*0*/ 
		0x7c,0xe3,0x39,0x82,0x9b,0x2f,0xff,0x87,0x34,0x8e,0x43,0x44,0xc4,0xde,0xe9,0xcb, /*1*/
		0x54,0x7b,0x94,0x32,0xa6,0xc2,0x23,0x3d,0xee,0x4c,0x95,0x0b,0x42,0xfa,0xc3,0x4e, /*2*/ 
		0x08,0x2e,0xa1,0x66,0x28,0xd9,0x24,0xb2,0x76,0x5b,0xa2,0x49,0x6d,0x8b,0xd1,0x25, /*3*/ 
		0x72,0xf8,0xf6,0x64,0x86,0x68,0x98,0x16,0xd4,0xa4,0x5c,0xcc,0x5d,0x65,0xb6,0x92, /*4*/ 
		0x6c,0x70,0x48,0x50,0xfd,0xed,0xb9,0xda,0x5e,0x15,0x46,0x57,0xa7,0x8d,0x9d,0x84, /*5*/ 
		0x90,0xd8,0xab,0x00,0x8c,0xbc,0xd3,0x0a,0xf7,0xe4,0x58,0x05,0xb8,0xb3,0x45,0x06, /*6*/ 
		0xd0,0x2c,0x1e,0x8f,0xca,0x3f,0x0f,0x02,0xc1,0xaf,0xbd,0x03,0x01,0x13,0x8a,0x6b, /*7*/
		0x3a,0x91,0x11,0x41,0x4f,0x67,0xdc,0xea,0x97,0xf2,0xcf,0xce,0xf0,0xb4,0xe6,0x73, /*8*/ 
		0x96,0xac,0x74,0x22,0xe7,0xad,0x35,0x85,0xe2,0xf9,0x37,0xe8,0x1c,0x75,0xdf,0x6e, /*9*/
		0x47,0xf1,0x1a,0x71,0x1d,0x29,0xc5,0x89,0x6f,0xb7,0x62,0x0e,0xaa,0x18,0xbe,0x1b, /*a*/
		0xfc,0x56,0x3e,0x4b,0xc6,0xd2,0x79,0x20,0x9a,0xdb,0xc0,0xfe,0x78,0xcd,0x5a,0xf4, /*b*/ 
		0x1f,0xdd,0xa8,0x33,0x88,0x07,0xc7,0x31,0xb1,0x12,0x10,0x59,0x27,0x80,0xec,0x5f, /*c*/ 
		0x60,0x51,0x7f,0xa9,0x19,0xb5,0x4a,0x0d,0x2d,0xe5,0x7a,0x9f,0x93,0xc9,0x9c,0xef, /*d*/ 
		0xa0,0xe0,0x3b,0x4d,0xae,0x2a,0xf5,0xb0,0xc8,0xeb,0xbb,0x3c,0x83,0x53,0x99,0x61, /*e*/ 
		0x17,0x2b,0x04,0x7e,0xba,0x77,0xd6,0x26,0xe1,0x69,0x14,0x63,0x55,0x21,0x0c,0x7d  /*f*/
	}; 
	memcpy(Sbox, sBox, 256);
	memcpy(InvSbox, invsBox, 256);
	KeyExpansion(key, w);
}

AES::~AES()
{

}
///////////加密函数///////////////////////////
unsigned char* AES::Cipher(unsigned char* input)
{
	unsigned char state[4][4];
	int i,r,c;
////将数组转换为矩阵///////////////////
	for(r=0; r<4; r++)
	{
		for(c=0; c<4 ;c++)
		{
			state[r][c] = input[c*4+r];
		}
	}

	AddRoundKey(state,w[0]);    ///////////////子密钥相加///////////////////
    
	for(i=1;i<=9;i++){
    	SubBytes(state);
    	ShiftRows(state);
    	MixColumns(state);
    	AddRoundKey(state,w[i]);
	} 
    SubBytes(state);
    ShiftRows(state);
    AddRoundKey(state,w[i]);
    
	for(r=0; r<4; r++)
	{
		for(c=0; c<4 ;c++)
		{
			input[c*4+r] = state[r][c];
		}
	}

	return input;
}
//////////////////////解密函数/////////////////////////
unsigned char* AES::InvCipher(unsigned char* input)
{
	unsigned char state[4][4];
	int i,r,c;

	for(r=0; r<4; r++)
	{
		for(c=0; c<4 ;c++)
		{
			state[r][c] = input[c*4+r];
		}
	}

	AddRoundKey(state, w[10]);
    InvShiftRows(state); 
    InvSubBytes(state); 
    
     for(i=9;i>=1;i--){
     	AddRoundKey(state,w[i]);
     	InvMixColumns(state);
     	InvShiftRows(state);
     	InvSubBytes(state);
     	
	 }
     
    AddRoundKey(state,w[i]);
     
	for(r=0; r<4; r++)
	{
		for(c=0; c<4 ;c++)
		{
			input[c*4+r] = state[r][c];
		}
	}

	return input;
}
/////////////////对明文进行分组加密////////////////
void* AES::Cipher(void* input, int length)
{
	unsigned char* in = (unsigned char*) input;
	int i;
	if(!length)
	{
		while(*(in+length++));
		in = (unsigned char*) input;
	}
	for(i=0; i<length; i+=16)
	{
		Cipher(in+i);
	}
	return input;
}
////////////////////对密文进行分组解密/////////////////////
void* AES::InvCipher(void* input, int length)
{
	unsigned char* in = (unsigned char*) input;
	int i;
	for(i=0; i<length; i+=16)
	{
		InvCipher(in+i);
	}
	return input;
}
////////////////////////密钥扩展///////////////////////////
void AES::KeyExpansion(unsigned char* key, unsigned char w[][4][4])
{
	int i,j,r,c;
	unsigned char rc[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36};
	for(r=0; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			w[0][r][c] = key[r+c*4];
		}
	}
	for(i=1; i<=10; i++)
	{
		for(j=0; j<4; j++)
		{
			unsigned char t[4];
			for(r=0; r<4; r++)
			{
				t[r] = j ? w[i][r][j-1] : w[i-1][r][3];
			}
			if(j == 0)
			{
				unsigned char temp = t[0];
				for(r=0; r<3; r++)
				{
					t[r] = Sbox[t[(r+1)%4]];
				}
				t[3] = Sbox[temp];
				t[0] ^= rc[i-1];
			}
			for(r=0; r<4; r++)
			{
				w[i][r][j] = w[i-1][r][j] ^ t[r];
			}
		}
	}
}
////////////////伽罗华域内的两个字符做乘法运算///////////////
unsigned char AES::FFmul(unsigned char a, unsigned char b)
{
	unsigned char bw[4];
	unsigned char res=0;
	int i;
	bw[0] = b;
	for(i=1; i<4; i++)
	{
		bw[i] = bw[i-1]<<1;
		if(bw[i-1]&0x80)
		{
			bw[i]^=0x1b;
		}
	}
	for(i=0; i<4; i++)
	{
		if((a>>i)&0x01)
		{
			res ^= bw[i];
		}
	}
	return res;
}
///////////////字节替换//////////////////////
void AES::SubBytes(unsigned char state[][4])
{
	int r,c;
	for(r=0; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			state[r][c] = Sbox[state[r][c]];
		}
	}
}
/////////////////////行位移//////////////////
void AES::ShiftRows(unsigned char state[][4])
{
	unsigned char t[4];
	int r,c;
	for(r=1; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			t[c] = state[r][(c+r)%4];
		}
		for(c=0; c<4; c++)
		{
			state[r][c] = t[c];
		}
	}
}
/////////////////////列混合///////////////////
void AES::MixColumns(unsigned char state[][4])
{
	unsigned char t[4];
	int r,c;
	for(c=0; c< 4; c++)
	{
		for(r=0; r<4; r++)
		{
			t[r] = state[r][c];
		}
		for(r=0; r<4; r++)
		{
			state[r][c] = FFmul(0x02, t[r])
						^ FFmul(0x03, t[(r+1)%4])
						^ FFmul(0x01, t[(r+2)%4])
						^ FFmul(0x01, t[(r+3)%4]);
		}
	}
}
//////////////////子密钥相加/////////////////////
void AES::AddRoundKey(unsigned char state[][4], unsigned char k[][4])
{
	int r,c;
	for(c=0; c<4; c++)
	{
		for(r=0; r<4; r++)
		{
			state[r][c] ^= k[r][c];
		}
	}
}
/////////////////字节替换的逆运算////////////////////
void AES::InvSubBytes(unsigned char state[][4])
{
	int r,c;
	for(r=0; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			state[r][c] = InvSbox[state[r][c]];
		}
	}
}
////////////////////行位移的逆运算///////////////////
void AES::InvShiftRows(unsigned char state[][4])
{
	unsigned char t[4];
	int r,c;
	for(r=1; r<4; r++)
	{
		for(c=0; c<4; c++)
		{
			t[c] = state[r][(c-r+4)%4];
		}
		for(c=0; c<4; c++)
		{
			state[r][c] = t[c];
		}
	}
}
///////////////////列混合的逆运算///////////////
void AES::InvMixColumns(unsigned char state[][4])
{
	unsigned char t[4];
	int r,c;
	for(c=0; c< 4; c++)
	{
		for(r=0; r<4; r++)
		{
			t[r] = state[r][c];
		}
		for(r=0; r<4; r++)
		{
			state[r][c] = FFmul(0x0e, t[r])
						^ FFmul(0x0b, t[(r+1)%4])
						^ FFmul(0x0d, t[(r+2)%4])
						^ FFmul(0x09, t[(r+3)%4]);
		}
	}
}


void print(unsigned char* state)
{
	int i;
	for(i=0; i<16; i++)
	{
		printf("%s%X ",state[i]>15 ? "" : "0", state[i]);
	}
	printf("\n");
}

int main(int argc, char* argv[])
{

//	unsigned char input[] = 
//	{
//		0x19, 0xa0, 0x9a, 0xe9, 
//		0x3d, 0xf4, 0xc6, 0xf8, 
//		0xe3, 0xe2, 0x8d, 0x48, 
//		0xbe, 0x2b, 0x2a, 0x08
//	};
//	
//
//
//	unsigned char key[] = 
//	{
//		0x2b, 0x28, 0xab, 0x09, 
//		0x7e, 0xae, 0xf7, 0xcf, 
//		0x15, 0xd2, 0x15, 0xef, 
//		0x16, 0xa6, 0x88, 0x3c
//	};
//	



	unsigned char input[] = 
	{
		0x32, 0x43, 0xf6, 0xa8, 
		0x88, 0x5a, 0x30, 0x8d, 
		0x31, 0x31, 0x98, 0xa2, 
		0xe0, 0x37, 0x07, 0x34
	};
	unsigned char key[] = 
	{
		0x2b, 0x7e, 0x15, 0x16, 
		0x28, 0xae, 0xd2, 0xa6, 
		0xab, 0xf7, 0x15, 0x88, 
		0x09, 0xcf, 0x4f, 0x3c
	};
	AES aes(key);
	
	printf("Input:\n");
	print(input);

	aes.Cipher(input);
	printf("After Cipher:\n");
	print(input);

	aes.InvCipher(input);
	printf("After InvCipher:\n");
	print(input);


	return 0;
}

AES.h

///////////////////////////////
// http://mingcn.cnblogs.com //
//  xelz CopyRight (c) 2010  //
///////////////////////////////


#if !defined(AFX_AES_H__6BDD3760_BDE8_4C42_85EE_6F7A434B81C4__INCLUDED_)
#define AFX_AES_H__6BDD3760_BDE8_4C42_85EE_6F7A434B81C4__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include "stdafx.h"

class AES  
{
public:
	AES(unsigned char* key);
	virtual ~AES();
	unsigned char* Cipher(unsigned char* input);
	unsigned char* InvCipher(unsigned char* input);
	void* Cipher(void* input, int length=0);
	void* InvCipher(void* input, int length);

private:
	unsigned char Sbox[256];
	unsigned char InvSbox[256];
	unsigned char w[11][4][4];

	void KeyExpansion(unsigned char* key, unsigned char w[][4][4]);
	unsigned char FFmul(unsigned char a, unsigned char b);

	void SubBytes(unsigned char state[][4]);
	void ShiftRows(unsigned char state[][4]);
	void MixColumns(unsigned char state[][4]);
	void AddRoundKey(unsigned char state[][4], unsigned char k[][4]);

	void InvSubBytes(unsigned char state[][4]);
	void InvShiftRows(unsigned char state[][4]);
	void InvMixColumns(unsigned char state[][4]);
};

#endif // !defined(AFX_AES_H__6BDD3760_BDE8_4C42_85EE_6F7A434B81C4__INCLUDED_)

StdAfx.h

 

// stdafx.h : include file for standard system include files,
//  or project specific include files that are used frequently, but
//      are changed infrequently
//

#if !defined(AFX_STDAFX_H__B4FEAA5A_7DE2_4988_9BAB_65CC27882DE5__INCLUDED_)
#define AFX_STDAFX_H__B4FEAA5A_7DE2_4988_9BAB_65CC27882DE5__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#define WIN32_LEAN_AND_MEAN		// Exclude rarely-used stuff from Windows headers

#include <stdio.h>

// TODO: reference additional headers your program requires here

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_STDAFX_H__B4FEAA5A_7DE2_4988_9BAB_65CC27882DE5__INCLUDED_)

运行结果截图：

 

 

posted @ 2020-06-16 20:20  陌默安  阅读(4561)  评论(0)  编辑  收藏  举报