// Cipher is the main function that encrypts the PlainText.
void cipher(int offset)
{
int i, j, round = 0;
//Copy the input PlainText to state array.
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
state[i][j] = temp_buffer[i][j];
}
}
#ifdef SHIFT_ROWS
for (round = 0; round <= nr; round++)
shift_rows();
#elif defined(MIX_COLUMNS)
for (round = 0; round <= nr; round++)
mix_columns();
#elif defined(ADD_ROUND_KEY)
for (round = 0; round <= nr; round++)
add_round_key(nr);
#elif defined(SUB_BYTES)
for (round = 0; round <= nr; round++)
sub_bytes();
#else
// Add the First round key to the state before starting the rounds.
add_round_key(0);
// There will be nr rounds.
// The first nr-1 rounds are identical.
// These nr-1 rounds are executed in the loop below.
for (round = 1; round < nr; round++) {
sub_bytes();
shift_rows();
mix_columns();
add_round_key(round);
}
// The last round is given below.
// The MixColumns function is not here in the last round.
sub_bytes();
shift_rows();
add_round_key(nr);
#endif
// The encryption process is over.
// Copy the state array to output array.
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
output_file_buffer[offset + i * 4 + j] = state[i][j];
}
}
}
void cipher(uint8_t *in, uint8_t *out, uint8_t *w) {
uint8_t state[4*Nb];
uint8_t r, i, j;
for (i = 0; i < 4; i++) {
for (j = 0; j < Nb; j++) {
state[Nb*i+j] = in[i+4*j];
}
}
add_round_key(state, w, 0);
for (r = 1; r < Nr; r++) {
sub_bytes(state);
shift_rows(state);
mix_columns(state);
add_round_key(state, w, r);
}
sub_bytes(state);
shift_rows(state);
add_round_key(state, w, Nr);
for (i = 0; i < 4; i++) {
for (j = 0; j < Nb; j++) {
out[i+4*j] = state[Nb*i+j];
}
}
}
void cipher(uint8_t *in, uint8_t **key_schedule, uint8_t n_k, uint8_t n_r) {
uint8_t *state;
state = malloc(BLOCK_LENGTH_IN_BYTES * sizeof(uint8_t));
if(state == NULL) {
printf("malloc returned NULL in cipher");
exit(1);
}
memcpy(state, in, BLOCK_LENGTH_IN_BYTES * sizeof(uint8_t));
if (DEBUG) {
printf("\nRound 0\n");
debug_print_block(state, " Start: ");
}
add_round_key(state, key_schedule, 0);
if (DEBUG) {
debug_print_key_schedule(key_schedule, 0);
}
for (int rnd = 1; rnd < n_r; rnd++) {
if (DEBUG) printf("\n\nRound %2d\n", rnd);
debug_print_block(state, " Start: ");
sub_bytes(state);
debug_print_block(state, " Subst: ");
shift_rows(state);
debug_print_block(state, " Shift: ");
mix_columns(state);
debug_print_block(state, " Mxcol: ");
add_round_key(state, key_schedule, rnd);
debug_print_key_schedule(key_schedule, rnd);
}
if (DEBUG) printf("\n\nRound 10\n");
debug_print_block(state, " Start: ");
sub_bytes(state);
debug_print_block(state, " Subst: ");
shift_rows(state);
debug_print_block(state, " Shift: ");
add_round_key(state, key_schedule, n_r);
debug_print_key_schedule(key_schedule, 10);
debug_print_block(state, "\n\nCIPHER\n");
}
void aes_enc(aes_ctx_t *ctx) {
int i;
add_roundkey(ctx->state, ctx->expkey, 0);
for(i = 1; i < NR; i++) {
sub_bytes(ctx->state);
shift_rows(ctx->state);
mix_columns(ctx->state, FOR_MIX);
add_roundkey(ctx->state, ctx->expkey, i);
}
sub_bytes(ctx->state);
shift_rows(ctx->state);
add_roundkey(ctx->state, ctx->expkey, NR);
}
void encode_block(BYTE* counter, BYTE* dst, BYTE round_key[ROUND_KEY_SIZE][BLOCK_SIZE]){
unsigned char temp[BLOCK_SIZE];
xor_key(counter, temp, round_key[0]);
for(int i = 1; i < ROUNDS; i++){
sub_bytes(temp, dst);
shift_rows(dst, temp);
mix_columns(temp, dst);
xor_key(dst, temp, round_key[i]);
}
sub_bytes(temp,dst);
shift_rows(dst,temp);
xor_key(temp,dst,round_key[ROUNDS]);
}
void aes_dec(aes_ctx_t *ctx) {
int i;
uint32_t *expkey = ctx->expkey;
uint8_t *state = ctx->state;
add_roundkey(state, expkey, NR);
inv_shift_rows(state);
inv_sub_bytes(state);
for(i = NR - 1; i > 0; i--) {
add_roundkey(state, expkey, i);
mix_columns(state, INV_MIX);
inv_shift_rows(state);
inv_sub_bytes(state);
}
add_roundkey(state, expkey, 0);
}
void lnc_aes_dec(void *context) {
lnc_aes_ctx_t *ctx = context;
int i;
uint32_t *expkey = ctx->expkey;
uint8_t *state = ctx->state;
add_roundkey(state, expkey, Nr);
inv_shift_rows(state);
inv_sub_bytes(state);
for(i = Nr - 1; i > 0; i--) {
add_roundkey(state, expkey, i);
mix_columns(state, INV_MIX);
inv_shift_rows(state);
inv_sub_bytes(state);
}
add_roundkey(state, expkey, 0);
}
void aes_encrypt(aes_ctx *ctx, const byte *in, byte *out)
{
int i;
byte state[16];
memcpy(state, in, 16);
add_round_key(state, ctx->sub_key);
for (i = 1; i < 10; i++) {
sub_bytes(state);
shift_rows(state);
mix_columns(state);
add_round_key(state, ctx->sub_key + (i * 16));
}
sub_bytes(state);
shift_rows(state);
add_round_key(state, ctx->sub_key + (i * 16));
memcpy(out, state, 16);
}
void lnc_aes_enc(void *context) {
lnc_aes_ctx_t *ctx = context;
int i;
uint32_t *expkey = ctx->expkey;
uint8_t *state = ctx->state;
add_roundkey(state, expkey, 0);
for(i = 1; i < Nr; i++) {
sub_bytes(state);
shift_rows(state);
mix_columns(state, FOR_MIX);
add_roundkey(state, expkey, i);
}
sub_bytes(state);
shift_rows(state);
add_roundkey(state, expkey, Nr);
}
void test_mix_columns()
{
uint8_t state[16] = {
0x87,0x6E,0x46,0xA6,
0xF2,0x4C,0xE7,0x8C,
0x4D,0x90,0x4A,0xD8,
0x97,0xEC,0xC3,0x95
};
uint8_t ret_state[16] = {
0x47,0x37,0x94,0xED,
0x40,0xD4,0xE4,0xA5,
0xA3,0x70,0x3A,0xA6,
0x4C,0x9F,0x42,0xBC
};
mix_columns(state);
int ret = memcmp(ret_state, state, sizeof(ret_state));
CU_ASSERT_EQUAL(ret, 0);
}
static void aes_main(aes_key *key, uint8_t *state)
{
int i = 0;
uint8_t rk[16];
create_round_key(key->data, rk);
add_round_key(state, rk);
for (i = 1; i < key->nbr; i++) {
create_round_key(key->data + 16 * i, rk);
shift_rows(state);
mix_columns(state);
add_round_key(state, rk);
}
create_round_key(key->data + 16 * key->nbr, rk);
shift_rows(state);
add_round_key(state, rk);
}
/**
* This function is the overall application of the AES cipher in the context of
* a single state block matrix.
*
* For each state, we perform the four AES functions several times, in what are
* referred to as "rounds". The number of rounds we do depends on the size of
* the encryption key.
*/
void aes_cipher(uint8_t **state, aes_key_t *key) {
int round, num_rounds;
num_rounds = (key->size / 4) + 6;
add_round_key(state, 0, key->exp_block);
for (round = 1; round < num_rounds; round++) {
sub_bytes(state);
shift_rows(state);
mix_columns(state);
add_round_key(state, round, key->exp_block);
}
/* Don't mix columns on the last round */
sub_bytes(state);
shift_rows(state);
add_round_key(state, num_rounds, key->exp_block);
}
void Aes256::encrypt(unsigned char* buffer)
{
unsigned char i, rcon;
copy_key();
add_round_key(buffer, 0);
for (i = 1, rcon = 1; i < NUM_ROUNDS; ++i)
{
sub_bytes(buffer);
shift_rows(buffer);
mix_columns(buffer);
if (!(i & 1))
expand_enc_key(&rcon);
add_round_key(buffer, i);
}
sub_bytes(buffer);
shift_rows(buffer);
expand_enc_key(&rcon);
add_round_key(buffer, i);
}
void Aes256Encoder::Encrypt(MemoryData& rkey, const MemoryData& key,const MemoryData& salt, unsigned char* buffer)
{
unsigned char i, rcon;
copy_key(rkey, key, salt);
add_round_key(rkey.MutableData(), buffer, 0);
for (i = 1, rcon = 1; i < RoundCount; ++i)
{
sub_bytes(buffer);
shift_rows(buffer);
mix_columns(buffer);
if (!(i & 1))
expand_enc_key(rkey.MutableData(), &rcon);
add_round_key(rkey.MutableData(), buffer, i);
}
sub_bytes(buffer);
shift_rows(buffer);
expand_enc_key(rkey.MutableData(), &rcon);
add_round_key(rkey.MutableData(), buffer, i);
}
void aes128_ecb_encrypt(const uint8_t *plaintext, const uint8_t *key, uint8_t *ciphertext) {
int round;
memcpy(ciphertext, plaintext, 16);
key_schedule(key, round_keys);
add_round_key(ciphertext, round_keys);
for (round = 1; round < N_ROUNDS; round++) {
sub_bytes(ciphertext);
shift_rows(ciphertext);
mix_columns(ciphertext);
add_round_key(ciphertext, round_keys + 16 * round);
}
sub_bytes(ciphertext);
shift_rows(ciphertext);
add_round_key(ciphertext, round_keys + 160);
}
void test_mix_columns(){
unsigned char block[] = {0x87, 0x6e, 0x46, 0xa6,
0xf2, 0x4c, 0xe7, 0x8c,
0x4d, 0x90, 0x4a, 0xd8,
0x97, 0xec, 0xc3, 0x95, 0x00},
origblock[17];
unsigned char expected[] = {0x47, 0x37, 0x94, 0xed,
0x40, 0xd4, 0xe4, 0xa5,
0xa3, 0x70, 0x3a, 0xa6,
0x4c, 0x9f, 0x42, 0xbc, 0x00};
memcpy(origblock, block, 17);
mix_columns(block, 16);
print_block(block, 16);
printf("\n");
print_block(expected, 16);
printf("\n");
assert( bytencmp(block, expected, 16) == 0 );
inv_mix_columns(block, 16);
assert( bytencmp(block, origblock, 16) == 0);
print_block(block, 16);
printf("\n");
}
// Decrypts the input using AES-128 driven by tablefile; stores in output[4][4]
void decrypt_block(unsigned char input_block[16], unsigned char output_block[16],
unsigned char round_key[44][4], FILE* table, bool first) {
unsigned char state[4][4] = { { 0 } }; // Carries state of block through encryption
unsigned char* inv_poly = (unsigned char*)calloc(1,4);
// Initialize Substitution Boxes
unsigned char* s_box = (unsigned char*)calloc(1,256);
unsigned char* inv_s_box = (unsigned char*)calloc(1,256);
init_s_box(s_box, table);
invert_s_box(s_box, inv_s_box);
free(s_box);
init_poly(inv_poly, table, "INVP=");
// Copy input to initital state
for(int i=0; i<16; i++) {
state[i%4][i/4] = input_block[i];
}
// Print initial inputs and key schedule
inv_print_state(state, 0, "iinput", first);
inv_print_state(&(round_key[4*10]), 0, "ik_sch", first);
// Add initial round key
add_round_key(state, round_key, 10);
// Perform operations for rounds 1 to 9
for(int i=9; i>0; i--) {
inv_print_state(state, 10-i, "istart", first);
// Inverse Shift Rows
inv_shift_rows(state);
inv_print_state(state, 10-i, "is_row", first);
// Substitute Bytes
sub_bytes(state, inv_s_box);
inv_print_state(state, 10-i, "is_box", first);
// Add Round Key
inv_print_state(&(round_key[4*i]), 10-i, "ik_sch", first);
add_round_key(state, round_key, i);
inv_print_state(state, 10-i, "ik_add", first);
// Mix Columns
mix_columns(state, inv_poly);
}
// Final round operations
inv_print_state(state, 10, "istart", first);
// Shift Rows
inv_shift_rows(state);
inv_print_state(state, 10, "is_row", first);
// Substitute Bytes
sub_bytes(state, inv_s_box);
inv_print_state(state, 10, "is_box", first);
// Add Round Key
add_round_key(state, round_key, 0);
inv_print_state(&(round_key[4*0]), 10, "ik_sch", first);
// Store final state value in output_block, done
for(int i=0; i<16; i++) {
output_block[i] = state[i%4][i/4];
}
inv_print_state(state, 10, "ioutput", first);
free(inv_poly);
free(inv_s_box);
}
void testBug(void)
{
mix_columns(buf);
average();
ASSERT(1);
}
