#include <stdio.h>

// AES S-Box
unsigned char S[] = {
    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 };

// AES Inverse S-Box
unsigned char SI[] = {
    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 };

unsigned char mixColumn[] = {
    0x02, 0x03, 0x01, 0x01,
    0x01, 0x02, 0x03, 0x01,
    0x01, 0x01, 0x02, 0x03,
    0x03, 0x01, 0x01, 0x02
};

unsigned char rcon[] = {
    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x1b, 0x36
};

unsigned char invMixColumn[] = {
    0x0E, 0x0B, 0x0D, 0x09,
    0x09, 0x0E, 0x0B, 0x0D,
    0x0D, 0x09, 0x0E, 0x0B,
    0x0B, 0x0D, 0x09, 0x0E
};

void printM(unsigned char* state)
{
    for (int i = 0; i < 16; i++)
    {
        printf("%x ", state[i]);
    }
    printf("\n");
}

void copyM(unsigned char* state, unsigned char* out)
{
    for (int i = 0; i < 16; i++)
    {
        out[i] = state[i];
    }
}

unsigned char mul1(unsigned char x){
    return x;
}

unsigned char mul2(unsigned char x)
{
    if (x < 128){
        return (x << 1);
    }
    else
    {
        return ((x << 1) ^ 0x1B);
    }
}

unsigned char mul3(unsigned char x)
{
    return (mul2(x) ^ x);
}

unsigned char decideMix(unsigned char in, unsigned char method)
{
    if (method == 0x03)
    {
        return mul3(in);
    }
    else if (method == 0x02)
    {
        return mul2(in);
    }
    else
    {
        return in;
    }
}

void mixColumnOps(unsigned char* State)
{
    unsigned char temp[16] = {0};
    copyM(State, temp);

    for (int stateCount = 0; stateCount < 4; stateCount++)
    {
        unsigned char temp1 = temp[stateCount+0];
        unsigned char temp2 = temp[stateCount+4];
        unsigned char temp3 = temp[stateCount+8];
        unsigned char temp4 = temp[stateCount+12];

        State[stateCount+0] = decideMix(temp1,mixColumn[0]) ^ decideMix(temp2,mixColumn[1]) ^ decideMix(temp3,mixColumn[2]) ^ decideMix(temp4,mixColumn[3]);
        State[stateCount+4] = decideMix(temp1,mixColumn[4]) ^ decideMix(temp2,mixColumn[5]) ^ decideMix(temp3,mixColumn[6]) ^ decideMix(temp4,mixColumn[7]);
        State[stateCount+8] = decideMix(temp1,mixColumn[8]) ^ decideMix(temp2,mixColumn[9]) ^ decideMix(temp3,mixColumn[10]) ^ decideMix(temp4,mixColumn[11]);
        State[stateCount+12] = decideMix(temp1,mixColumn[12]) ^ decideMix(temp2,mixColumn[13]) ^ decideMix(temp3,mixColumn[14]) ^ decideMix(temp4,mixColumn[15]);
    }
}

void subBytes(unsigned char* State)
{
    for (int i = 0; i < 16; i++)
    {
        State[i] = S[State[i]];
    }
}

void leftRotate(unsigned char* arr, int startIndex, int d)
{
    for (int i = 0; i < d; i++)
    {
        unsigned char temp = arr[startIndex], i;

        for (i = startIndex; i < startIndex+3; i++)
        {
            arr[i] = arr[i + 1];
        }

        arr[i] = temp;
    }
}

void shiftRows(unsigned char* State)
{
    for (int i = 0; i < 4; i++)
    {
        leftRotate(State, i*4, i);
    }
}

void addRoundKey(unsigned char* State, unsigned char* key)
{
    for (int i = 0; i < 16; i++)
    {
        State[i] = State[i] ^ key[i];
    }
}

void printRowOne(unsigned char* state, int startIndex)
{
    for (int i = 0; i < 4; i++)
    {
        printf("%x \n", state[i*4 + startIndex]);
    }
    printf("\n");
}

void rotWord(unsigned char* state)
{
    unsigned char holderVal = state[12];
    for (int i = 0; i < 3; i++)
    {
        state[12+i] = state[13+i];
    }
    state[15] = holderVal;
}

void rowSubBytes(unsigned char* key)
{
    for (int i = 0; i < 4; i++)
    {
        key[12+i] = S[key[12+i]];
    }
}

void rowXor(unsigned char* key, unsigned char* holderState, int rconIndex)
{
    for (int k = 0; k < 13; k = k + 4)
    {
        if (k == 0)
        {
            for (int i = 0; i < 4; i++)
            {
                if (i == 0)
                    key[i] = holderState[i] ^ key[12+i] ^ rcon[rconIndex];
                else
                {
                    key[i] = holderState[i] ^ key[12+i];
                }
            }
        }
        else
        {
            for (int i = 0; i < 4; i++)
            {
                key[k+i] = holderState[k+i] ^ key[k+i-4];
            }
        }
    }
}

void inverseRowXor(unsigned char* key, int rconIndex)
{
    for (int k = 3; k > -1; k--)
    {
        if (k != 0)
        {
            for (int i = 0; i < 4; i++)
            {
                key[i*4+k] = key[i*4+k] ^ key[i*4+k-1];
            }
        }
    }
}

void copyArray(unsigned char* origin, unsigned char* copied)
{
    for (int i = 0; i < 16; i++)
    {
        copied[i] = origin[i];
    }
}

void xorColumnByIndex (unsigned char* first, int indexF, unsigned char* second, int indexS)
{
    for (int i = 0; i < 4; i++)
    {
        first[indexF+i] = first[indexF+i] ^ second[indexS+i];
    }
}

void transposeMatrix(unsigned char* state, unsigned char* copiedState)
{
    copyArray(state, copiedState);
    for(int i = 0; i < 4; i++)
    {
        state[i*4] = copiedState[i];
        state[i*4+1] = copiedState[i+4];
        state[i*4+2] = copiedState[i+8];
        state[i*4+3] = copiedState[i+12];
    }
}

void newKeyGenerate (unsigned char* key, int round, int inverse)
{
    if (inverse == 0)
    {
        unsigned char holderState[16];
        copyArray(key, holderState);

        rotWord(key);
        rowSubBytes(key);
        rowXor(key, holderState, round);
    }
    else
    {
        inverseRowXor(key, 0);

        unsigned char holderState[16];
        copyArray(key, holderState);
        rotWord(holderState);
        rowSubBytes(holderState);

        xorColumnByIndex(key,0,holderState,3);
        key[0] = key[0] ^ rcon[round];
    }
}

unsigned char testState[] = {
    0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16
};

unsigned char key[] = {
    0x54, 0x68, 0x61, 0x74, 0x73, 0x20, 0x6d, 0x79, 0x20, 0x4B, 0x75, 0x6E, 0x67, 0x20, 0x46, 0x75
};

unsigned char testKey[] = {
    0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c
};

unsigned char state[] = {
    0x54, 0x77, 0x6f, 0x20, 0x4f, 0xe6, 0x65, 0x20, 0x4e, 0x69, 0x6e, 0x65, 0x20, 0x54, 0x77, 0x6f
};

int main(void)
{
    newKeyGenerate(key,0,0);
    printM(key);
    newKeyGenerate(key,1,0);
    printM(key);
    newKeyGenerate(key,2,0);
    printM(key);
    newKeyGenerate(key,3,0);
    printM(key);

    return 0;
}