AES128.c

// AES-128

// Original Version from
// Ported and modified from C
// https://github.com/kokke/tiny-AES-c/blob/master/aes.c

const int Nb = 4;
const int Nk = 4;
const int Nr = 10;

const 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, 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 };

const unsigned char rsbox[] = { 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 };

const unsigned char Rcon[] = { 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
        0x36 };

unsigned char getSBoxValue(unsigned char num) {
    return sbox[num & 0xFF];
}

void KeyExpansion(unsigned char* RoundKey, unsigned char* Key) {
    int i, j, k;
    unsigned char tempa[4]; // Used for the column/row operations

    // The first round key is the key itself.
    for (i = 0; i < Nk; ++i) {
        RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
        RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
        RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
        RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
    }

    // All other round keys are found from the previous round keys.
    for (i = Nk; i < Nb * (Nr + 1); ++i) {
        {
            k = (i - 1) * 4;
            tempa[0] = RoundKey[k + 0];
            tempa[1] = RoundKey[k + 1];
            tempa[2] = RoundKey[k + 2];
            tempa[3] = RoundKey[k + 3];

        }

        if (i % Nk == 0) {

            {
                unsigned char u8tmp = tempa[0];
                tempa[0] = tempa[1];
                tempa[1] = tempa[2];
                tempa[2] = tempa[3];
                tempa[3] = u8tmp;
            }

            {
                tempa[0] = getSBoxValue(tempa[0]);
                tempa[1] = getSBoxValue(tempa[1]);
                tempa[2] = getSBoxValue(tempa[2]);
                tempa[3] = getSBoxValue(tempa[3]);
            }

            tempa[0] = (unsigned char) (tempa[0] ^ Rcon[i / Nk]);
        }

        j = i * 4;
        k = (i - Nk) * 4;
        RoundKey[j + 0] = (unsigned char) (RoundKey[k + 0] ^ tempa[0]);
        RoundKey[j + 1] = (unsigned char) (RoundKey[k + 1] ^ tempa[1]);
        RoundKey[j + 2] = (unsigned char) (RoundKey[k + 2] ^ tempa[2]);
        RoundKey[j + 3] = (unsigned char) (RoundKey[k + 3] ^ tempa[3]);
    }
}

void AES_init_ctx(unsigned char* RoundKey, unsigned char* key) {
    KeyExpansion(RoundKey, key);
}

void AddRoundKey(unsigned char round, unsigned char* state, unsigned char* RoundKey) {
    int i, j;
    for (i = 0; i < 4; ++i) {
        for (j = 0; j < 4; ++j) {
            state[i * 4 + j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j];
        }
    }
}

void SubBytes(unsigned char* state) {
    int i, j;
    for (i = 0; i < 4; ++i) {
        for (j = 0; j < 4; ++j) {
            state[i * 4 + j] = getSBoxValue(state[i * 4 + j]);
        }
    }
}

void ShiftRows(unsigned char* state) {
    unsigned char temp;
    temp = state[0 * 4 + 1];
    state[0 * 4 + 1] = state[1 * 4 + 1];
    state[1 * 4 + 1] = state[2 * 4 + 1];
    state[2 * 4 + 1] = state[3 * 4 + 1];
    state[3 * 4 + 1] = temp;
    temp = state[0 * 4 + 2];
    state[0 * 4 + 2] = state[2 * 4 + 2];
    state[2 * 4 + 2] = temp;
    temp = state[1 * 4 + 2];
    state[1 * 4 + 2] = state[3 * 4 + 2];
    state[3 * 4 + 2] = temp;
    temp = state[0 * 4 + 3];
    state[0 * 4 + 3] = state[3 * 4 + 3];
    state[3 * 4 + 3] = state[2 * 4 + 3];
    state[2 * 4 + 3] = state[1 * 4 + 3];
    state[1 * 4 + 3] = temp;
}

unsigned char xtime(unsigned char x) {
    return (unsigned char) ((x << 1) ^ (((x >> 7) & 1) * 0x1b));
}

void MixColumns(unsigned char* state) {
    int i;
    unsigned char Tmp, Tm, t;
    for (i = 0; i < 4; ++i) {
        t = state[i * 4 + 0];
        Tmp = (unsigned char) (state[i * 4 + 0] ^ state[i * 4 + 1] ^ state[i * 4 + 2] ^ state[i * 4 + 3]);
        Tm = (unsigned char) (state[i * 4 + 0] ^ state[i * 4 + 1]);
        Tm = xtime(Tm);
        state[i * 4 + 0] ^= Tm ^ Tmp;
        Tm = (unsigned char) (state[i * 4 + 1] ^ state[i * 4 + 2]);
        Tm = xtime(Tm);
        state[i * 4 + 1] ^= Tm ^ Tmp;
        Tm = (unsigned char) (state[i * 4 + 2] ^ state[i * 4 + 3]);
        Tm = xtime(Tm);
        state[i * 4 + 2] ^= Tm ^ Tmp;
        Tm = (unsigned char) (state[i * 4 + 3] ^ t);
        Tm = xtime(Tm);
        state[i * 4 + 3] ^= Tm ^ Tmp;
    }
}

unsigned char Multiply(unsigned char x, unsigned char y) {
    return (unsigned char) (((y & 1) * x) ^ ((y >> 1 & 1) * xtime(x)) ^ ((y >> 2 & 1) * xtime(xtime(x)))
            ^ ((y >> 3 & 1) * xtime(xtime(xtime(x))))
            ^ ((y >> 4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */
}

unsigned char getSBoxInvert(unsigned char num) {
    return rsbox[num & 0xFF];
}

// MixColumns function mixes the columns of the state matrix.
// The method used to multiply may be difficult to understand for the
// inexperienced.
// Please use the references to gain more information.
void InvMixColumns(unsigned char* state) {
    int i;
    unsigned char a, b, c, d;
    for (i = 0; i < 4; ++i) {
        a = state[i * 4 + 0];
        b = state[i * 4 + 1];
        c = state[i * 4 + 2];
        d = state[i * 4 + 3];

        state[i * 4 + 0] = (unsigned char) (Multiply(a, (unsigned char) 0x0e) ^ Multiply(b, (unsigned char) 0x0b) ^ Multiply(c, (unsigned char) 0x0d)
                ^ Multiply(d, (unsigned char) 0x09));
        state[i * 4 + 1] = (unsigned char) (Multiply(a, (unsigned char) 0x09) ^ Multiply(b, (unsigned char) 0x0e) ^ Multiply(c, (unsigned char) 0x0b)
                ^ Multiply(d, (unsigned char) 0x0d));
        state[i * 4 + 2] = (unsigned char) (Multiply(a, (unsigned char) 0x0d) ^ Multiply(b, (unsigned char) 0x09) ^ Multiply(c, (unsigned char) 0x0e)
                ^ Multiply(d, (unsigned char) 0x0b));
        state[i * 4 + 3] = (unsigned char) (Multiply(a, (unsigned char) 0x0b) ^ Multiply(b, (unsigned char) 0x0d) ^ Multiply(c, (unsigned char) 0x09)
                ^ Multiply(d, (unsigned char) 0x0e));
    }
}

// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
void InvSubBytes(unsigned char* state) {
    int i, j;
    for (i = 0; i < 4; ++i) {
        for (j = 0; j < 4; ++j) {
            state[j * 4 + i] = getSBoxInvert(state[j * 4 + i]);
        }
    }
}

void InvShiftRows(unsigned char* state) {
    unsigned char temp;

    temp = state[3 * 4 + 1];
    state[3 * 4 + 1] = state[2 * 4 + 1];
    state[2 * 4 + 1] = state[1 * 4 + 1];
    state[1 * 4 + 1] = state[0 * 4 + 1];
    state[0 * 4 + 1] = temp;

    temp = state[0 * 4 + 2];
    state[0 * 4 + 2] = state[2 * 4 + 2];
    state[2 * 4 + 2] = temp;

    temp = state[1 * 4 + 2];
    state[1 * 4 + 2] = state[3 * 4 + 2];
    state[3 * 4 + 2] = temp;

    temp = state[0 * 4 + 3];
    state[0 * 4 + 3] = state[1 * 4 + 3];
    state[1 * 4 + 3] = state[2 * 4 + 3];
    state[2 * 4 + 3] = state[3 * 4 + 3];
    state[3 * 4 + 3] = temp;
}

void Cipher(unsigned char* state, unsigned char* RoundKey) {
    int round = 0;
    AddRoundKey((unsigned char) 0, state, RoundKey);
    for (round = 1;; ++round) {
        SubBytes(state);
        ShiftRows(state);
        if (round == Nr) {
            break;
        }
        MixColumns(state);
        AddRoundKey((unsigned char) round, state, RoundKey);
    }
    // Add round key to last round
    AddRoundKey((unsigned char) Nr, state, RoundKey);
}

void InvCipher(unsigned char* state, unsigned char* RoundKey) {
    int round = 0;
    AddRoundKey((unsigned char) Nr, state, RoundKey);

    for (round = (Nr - 1);; --round) {
        InvShiftRows(state);
        InvSubBytes(state);
        AddRoundKey((unsigned char) round, state, RoundKey);
        if (round == 0) {
            break;
        }
        InvMixColumns(state);
    }

}

void AES_ECB_encrypt(unsigned char* RoundKey, unsigned char* buf) {
    Cipher(buf, RoundKey);
}

void AES_ECB_decrypt(unsigned char* RoundKey, unsigned char* buf) {
    InvCipher(buf, RoundKey);
}

unsigned int _binary___program_bin_start(unsigned char* message, unsigned int len) {
    unsigned char key[16];
    
    for(int i=0;i<16;i++)
        key[i] = (unsigned char)(i&0xFF);


    unsigned char roundKey[176];
    AES_init_ctx(roundKey, key);
    
    
    int res = 0;
    unsigned char data[16];
    for(int i=0;i<len;i+=16) {
        for(int j=0;j<16;j++)
            data[j] = 0;
        for(int j=0;j<16 && j<(len-i);j++)
            data[j] = message[i+j];
        
        AES_ECB_encrypt(roundKey, data); // reencrypt it to test
        AES_ECB_decrypt(roundKey, data); // if encrypt and decryption is symmetric
        
        res ^= data[0];
    }
    
    return res;
}