def encrypt(message, expanded_key, number_of_rounds, iv=''):
encrypted_text = []
for i in range(0, len(message), 16):
encrypted_text += block_cipher_encrypt(message[i:i + 16], expanded_key,
number_of_rounds)
encrypted_text = [chr(i) for i in encrypted_text]
return ''.join(encrypted_text)
def decrypt(encrypted_message, expanded_key, number_of_rounds, iv):
print('OFB Decrypt')
decrypted_text = []
for i in range(0, len(encrypted_message), 16):
initial = encrypted_message[i : i + 16]
block_decrypted_text = block_cipher_encrypt(iv, expanded_key, number_of_rounds)
block_decrypted_text = array_xor(block_decrypted_text, initial)
decrypted_text += block_decrypted_text
iv = initial[0:16]
decrypted_text = [chr(i) for i in decrypted_text]
return ''.join(decrypted_text)
def encrypt(message, expanded_key, number_of_rounds, iv):
encrypted_text = []
print('OFB Encrypt')
for i in range(0, len(message), 16):
initial = message[i : i + 16]
block_encypted_text = block_cipher_encrypt(iv, expanded_key, number_of_rounds)
block_encypted_text = array_xor(block_encypted_text, initial)
encrypted_text += block_encypted_text
iv = block_encypted_text[0:16]
encrypted_text = [chr(i) for i in encrypted_text]
return ''.join(encrypted_text)
def encrypt(message, expanded_key, number_of_rounds, iv):
print('CBC Encrypt')
encrypted_text = []
for i in range(0, len(message), 16):
initial = message[i:i + 16] # lúc đầu i1 = 0 => i2 = 16
initial = array_xor(iv, initial)
block_encypted_text = block_cipher_encrypt(initial, expanded_key,
number_of_rounds)
encrypted_text += block_encypted_text
iv = block_encypted_text[
0:16] # cắt ra 1 đoạn mã hóa để làm iv tiếp theo
encrypted_text = [chr(i) for i in encrypted_text]
return ''.join(encrypted_text)