aes加密

#include<bits/stdc++.h>

using namespace std;
//al4f3dfe78e803fc10d5a8df4c632923
//acc1d6b8efb55a7b1323cfdf457311b5
string s = "(学号)a7b1323cfdf457311b5";
//string state[4][4];
unsigned char state[4][4] = {{0xac, 0xc1, 0xd6, 0xb8},
                             {0xef, 0xb5, 0x5a, 0x7b},
                             {0x13, 0x23, 0xcf, 0xdf},
                             {0x45, 0x73, 0x11, 0xb5},
};


//void ShiftRows() {
//    string 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];
//        }
//    }
//}

unsigned char 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;
}

void MixColumns() {
    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]);
        }
    }
}


int main() {
    //cout <<s.length();
//    int l = 0;
//    for (int i = 0; i < 4; ++i) {
//        for (int j = 0; j < 4; ++j) {
//            state[j][i] = (s.substr(l, 1) + s.substr(l + 1, 1));
//            l += 2;
//        }
//    }
//
//    cout << "填入：\n";
//    for (int i = 0; i < 4; ++i) {
//        for (int j = 0; j < 4; ++j) {
            printf("%02x ", state[i][j]);
//            cout << state[i][j] << ' ';
//        }
//        cout << endl;
//    }
//    ShiftRows();
//    cout << "变换后：\n";
    MixColumns();
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            printf("%02x ", state[i][j]);
//            cout << state[i][j] << ' ';
        }
        cout << endl;
    }
    return 0;
}