aes.cpp

AES加密算法vC++实现类源码 hello 1243435

	return InitAES(new AES(),inSize,key,keySize,type);
}
/*
*/
void CipherLoop(AES *aes)
{
	unsigned char temp[4];
	unsigned long *word8 = aes->Word,
				  *State = aes->State;

	int		Nb		= aes->Nb,
			Nr		= aes->Nr;

	int r;
	for (r = 0; r < Nb; ++r)
    {
		State[r] ^= word8[r];
    }
	for (int round =1; round <Nr; ++round)
	{
		word8 += Nb;
		/*
		假设Nb=4;
		---------------------
		| s0 | s1 | s2 | s3 |
		---------------------
		| s4 | s5 | s6 | s7 |
		---------------------
		| s8 | s9 | sa | sb |
		---------------------
		| sc | sd | se | sf |
		---------------------
		|    |    |    |    |
		---------------------
		|    |    |    |    |
		---------------------
		|    |    |    |    |
		---------------------
		*/
		memcpy(State+Nb,State,12);
		/*
		Nb=4;
		---------------------
		| s0 |    |    |    | 
		---------------------
		| s4 | s5 |    |    | 
		--------------------- 
		| s8 | s9 | sa |    | 
		---------------------
		| sc | sd | se | sf | 
		---------------------
		|    | s1 | s2 | s3 | 
		--------------------- 
		|    |    | s6 | s7 | 
		---------------------
		|    |    |    | sb |
		---------------------
		*/
		for(r =0; r<Nb; r++)
		{
			/*
			temp = {Sbox[s0],Sbox[s5],Sbox[sa],Sbox[sf]};
			*/
			temp[0] = Sbox[*((unsigned char*)State)];
			temp[1] = Sbox[*((unsigned char*)(State+1)+1)];
			temp[2] = Sbox[*((unsigned char*)(State+2)+2)];
			temp[3] = Sbox[*((unsigned char*)(State+3)+3)];

			*((unsigned char*)State)	= (unsigned char)(Log_02[temp[0]] ^ Log_03[temp[1]] ^ temp[2] ^ temp[3]);
			*((unsigned char*)State+1)	= (unsigned char)(Log_02[temp[1]] ^ Log_03[temp[2]] ^ temp[3] ^ temp[0]);
			*((unsigned char*)State+2)	= (unsigned char)(Log_02[temp[2]] ^ Log_03[temp[3]] ^ temp[0] ^ temp[1]);
			*((unsigned char*)State+3)	= (unsigned char)(Log_02[temp[3]] ^ Log_03[temp[0]] ^ temp[1] ^ temp[2]);
			
			*State ^= word8[r];
			State++;
		}
		State -= Nb;
	}
	
	memcpy(State+Nb,State,12);

	word8 += Nb;
	for(r =0; r<Nb; r++)
	{
		*((unsigned char*)State)   = Sbox[*(unsigned char*)State];
		*((unsigned char*)State+1) = Sbox[*((unsigned char*)(State+1)+1)];
		*((unsigned char*)State+2) = Sbox[*((unsigned char*)(State+2)+2)];
		*((unsigned char*)State+3) = Sbox[*((unsigned char*)(State+3)+3)];

		*State ^= word8[r];
		State++;
	}
}
/*
解密时进行Nr轮逆运算
AES * aes	运行时参数
*/
void InvCipherLoop(AES *aes)
{
	unsigned long *Word = aes->Word,
				  *State = aes->State;

	int		Nb		= aes->Nb,
			Nr		= aes->Nr;

	unsigned char temp[4];

	int r =0;
	Word += Nb*Nr;
	for (r = 0; r < Nb; ++r)
    {
		State[r] ^= Word[r];
    }

	State -= 3;

	for (int round = Nr-1; round > 0; --round)
	{
		/*
		假设Nb=4;
		--------------------- 
		|    |    |    |    | 
		--------------------- 
		|    |    |    |    | 
		--------------------- 
		|    |    |    |    | 
		--------------------- 
		| s0 | s1 | s2 | s3 | 
		--------------------- 
		| s4 | s5 | s6 | s7 |  
		---------------------  
		| s8 | s9 | sa | sb | 
		--------------------- 
		| sc | sd | se | sf | 
		--------------------- 
		*/
		memcpy(State,State+Nb,12);
		/*
		Nb=4;
		---------------------
		|    |    |    | s7 |
		---------------------
		|    |    | sa | sb |
		--------------------- 
		|    | sd | se | sf |
		---------------------
		| s0 | s1 | s2 | s3 |
		---------------------
		| s4 | s5 | s6 |    | 
		--------------------- 
		| s8 | s9 |    |    |
		---------------------
		| sc |    |    |    |
		---------------------
		*/

		Word -= Nb;
		State += Nb+2;

		for(r = Nb-1; r >= 0; r--)
		{
			/*
			temp = {iSbox[s0],iSbox[sd],iSbox[sa],iSbox[s7]};
			*/
			temp[0] = iSbox[*(unsigned char*)State];
			temp[1] = iSbox[*((unsigned char*)(State-1)+1)];
			temp[2] = iSbox[*((unsigned char*)(State-2)+2)];
			temp[3] = iSbox[*((unsigned char*)(State-3)+3)];

			*(unsigned long*)temp ^= Word[r];

			*(unsigned char*)State	   = (unsigned char)(Log_0e[temp[0]] ^ Log_0b[temp[1]] ^ Log_0d[temp[2]] ^ Log_09[temp[3]]);
			*((unsigned char*)State+1) = (unsigned char)(Log_0e[temp[1]] ^ Log_0b[temp[2]] ^ Log_0d[temp[3]] ^ Log_09[temp[0]]);
			*((unsigned char*)State+2) = (unsigned char)(Log_0e[temp[2]] ^ Log_0b[temp[3]] ^ Log_0d[temp[0]] ^ Log_09[temp[1]]);
			*((unsigned char*)State+3) = (unsigned char)(Log_0e[temp[3]] ^ Log_0b[temp[0]] ^ Log_0d[temp[1]] ^ Log_09[temp[2]]);

			State --;
		}
		State -= 2;
	}

	Word -= Nb;
	memcpy(State,State+Nb,12);

	State += Nb+2;
	for(r = Nb-1; r >= 0; r--)
	{

		*(unsigned char*)State	   = iSbox[*(unsigned char*)State];
		*((unsigned char*)State+1) = iSbox[*((unsigned char*)(State-1)+1)];
		*((unsigned char*)State+2) = iSbox[*((unsigned char*)(State-2)+2)];
		*((unsigned char*)State+3) = iSbox[*((unsigned char*)(State-3)+3)];
			
		*State ^= Word[r];
		State --;
	}
}
/*
*--------------------------------------------
*|k0|k1|k2|k3|k4|k5|k6|k7|k8|k9|.......|Nk*4|
*--------------------------------------------
*Nr轮密钥库
*每个密钥列长度为Nb
*---------------------
*| k0 | k1 | k2 | k3 |
*---------------------
*| k4 | k5 | k6	| k7 |
*---------------------
*| k8 | k9 | ka	| kb |
*---------------------
*| kc |	kd | ke	| kf |
*---------------------
*/
unsigned long* keyExpansion(unsigned char* key, int Nb, int Nr, int Nk)
{
	unsigned long *w =new unsigned long[Nb * (Nr+1)];  // 4 columns of bytes corresponds to a word
  
	memcpy(w,key,Nk<<2);
	unsigned long temp;
	
    for (int c = Nk; c < Nb * (Nr+1); ++c)
    {
		//把上一轮的最后一行放入temp
		temp = w[c-1];
		//判断是不是每一轮密钥的第一行
		if (c % Nk == 0)  
		{
			//左旋8位
			temp = (temp<<8)|(temp>>24);
			//查Sbox表
			SubWord((unsigned char*)&temp);
			temp ^= Rcon[c/Nk];
		}
		else if ( Nk > 6 && (c % Nk == 4) )  
		{
			SubWord((unsigned char*)&temp);
		}
		//w[c-Nk] 为上一轮密钥的第一行
        w[c] = w[c-Nk] ^ temp;
	}
	return w;
}

unsigned char* SubWord(unsigned char* word)
{
    word[0] = Sbox[ word[0] ];
    word[1] = Sbox[ word[1] ];
    word[2] = Sbox[ word[2] ];
    word[3] = Sbox[ word[3] ];
    return word;
}
/*
释放AES结构和State和密钥库word
*/
void freeAES(AES *aes)
{
//	for(int i=0;i<aes->Nb;i++)
//	{
//		printf("%d\n",i);
//		free(aes->State[i]);
//		free(aes->Word[i]);
//	}
//	printf("sdffd");
}