diff options
Diffstat (limited to 'main.py')
| -rw-r--r-- | main.py | 54 |
1 files changed, 38 insertions, 16 deletions
@@ -1,7 +1,11 @@ #!/usr/bin/python +from pprint import pprint + +from constants import round_constants +from constants import sbox + matrix_size = 4 -round_constants = [0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36] def hex_to_matrix(hex_array): @@ -29,24 +33,42 @@ def shift_matrix(matrix): def key_expansion(round_key): round_keys = [round_key] - for i in range(1, 11): - # Move top byte to bottom - top = round_key[0][3] - for row in range(matrix_size - 1): - round_key[row][3] = round_key[row + 1][3] - # TODO: sBox - round_key[3][3] = top ^ round_constants[i] - # Modify first column by XORing it with the previous round key - for column in range(matrix_size - 1): - for row in range(matrix_size): - round_key[row][column] = round_key[row][column] ^ round_keys[i - 1][row][column] + print(round_key) + for r in range(0, 10): + last = round_key[3] + + round_key[3] = round_last(round_key[3], r) + round_key[0] = xor_matrix(round_key[0], round_key[3]) + round_key[1] = xor_matrix(round_key[1], round_key[0]) + round_key[2] = xor_matrix(round_key[2], round_key[1]) + round_key[3] = xor_matrix(last, round_key[2]) + + print(round_key) round_keys.append(round_key) - return round_keys + + +def xor_matrix(first, second): + for i in range(4): + first[i] = first[i] ^ second[i] + return first + + +def round_last(round_key, r): + # Shift bottom row + last_column = round_key[1:] + round_key[:1] + + # Byte substitution (sbox uses hex representation as index) + for column in range(matrix_size): + last_column[column] = sbox[last_column[column]] + + # Adding round constant + last_column[0] = last_column[0] ^ round_constants[r] + return last_column test_key = text_to_hex("Thats my Kung Fu") test_text = text_to_hex("Two One Nine Two") -print(hex_to_matrix(test_key)) -print(key_expansion(hex_to_matrix(test_key))) -print(shift_matrix(hex_to_matrix(test_key))) +pprint(hex_to_matrix(test_key)) +print("\n\n") +pprint(key_expansion(hex_to_matrix(test_key))) |