AES算法的c++实现

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1、AES.h

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<iostream>
#include<cmath>

class AES{
public:
    AES(unsigned char* key);
    virtual ~AES();
    unsigned char* Cipher(unsigned char* input);//16字节为一组
    unsigned char* InvCipher(unsigned char* input);
    void* Cipher(void* input, int length=0);//初始化过了
    void* InvCipher(void* input, int length);

private:
    unsigned char Sbox[256];
    unsigned char InvSbox[256];//1字节=8位
    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]);
};

2、AES.cpp

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

AES::~AES(){}//析构函数

unsigned char* AES::Cipher(unsigned char* input){//只往后16个字节
    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[0]);//原秘钥，一共11轮密钥

    for(i=1; i<=10; i++){
        SubBytes(state);
        ShiftRows(state);
        if(i!=10)MixColumns(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;
}

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]);//注意逆向的顺序
    for(i=9; i>=0; i--){
        InvShiftRows(state);
        InvSubBytes(state);
        AddRoundKey(state, w[i]);
        if(i){
            InvMixColumns(state);
        }
    }
    
    for(r=0; r<4; r++){
        for(c=0; c<4 ;c++){
            input[c*4+r] = state[r][c];
        }
    }

    return input;
}

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;
}

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;
}

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};//轮常量
    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){
                for(r=0; r<=3; r++){
                    t[r] = Sbox[t[(r+1)%4]];
                }
                t[0] ^= rc[i-1];
            }
            for(r=0; r<4; r++){
                w[i][r][j] = w[i-1][r][j] ^ t[r];
            }
        }
    }
}
//有限域乘法
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;
}

//字节替代
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]];
        }
    }
}
//行移位变换
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];
        }
    }
}
//列混淆变换
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]);
        }
    }
}
//轮密钥加变换，正逆是一样的，异或
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];
        }
    }
}
//逆字节替代
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]];
        }
    }
}
//逆行移位变换
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];
        }
    }
}
//逆列混淆变换
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]);
        }
    }
}

3、main.cpp

#include "AES.h"
void print(unsigned char* state);
int main(int argc, char* argv[]){
    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
    };//128位，16字节
    AES aes(key);
    
    printf("Input:
");
    print(input);
    
    aes.Cipher(input);
    printf("After Cipher:
");
    print(input);
    
    aes.InvCipher(input);
    printf("After InvCipher:
");
    print(input);
   
    int j;
    printf("
");
    char str[32] = "Hello,My AES Cipher!";
    for(j=0; j<32; j++)printf("%X ",(unsigned char)str[j]);
    printf("
");
    aes.Cipher((void *)str);
    for(j=0; j<32; j++)printf("%X ",(unsigned char)str[j]);
    printf("
");
    aes.InvCipher((void *)str,21);
    for(j=0; j<32; j++)printf("%X ",(unsigned char)str[j]);
    printf("
");
    
    return 0;
}

void print(unsigned char* state){
    int i;
    /*for(i=0; i<16; i++){
        printf("%s%X ",state[i]>15 ? "" : "0", state[i]);
    }*/
    for(int i=0;i<16;i++) printf("%02x ",state[i]);
    printf("
");
}