def multiply_ciphers(cipher1, cipher2, public_key_file):
cipher1 = pyrsa_sq_mul.unpack_bigint(cipher1)
cipher2 = pyrsa_sq_mul.unpack_bigint(cipher2)
key = open(public_key_file,'r').read()
rsakey = RSA.importKey(key)
mult_cipher_int = (cipher1 * cipher2) % rsakey.n
mult_cipher_str = pyrsa_sq_mul.pack_bigint(mult_cipher_int)
return mult_cipher_str
def decrypt_RSA(private_key_file, cipher, state='sm'):
key = open(private_key_file,'r').read()
rsakey = RSA.importKey(key)
if state == 'sm':
cipher_int = pyrsa_sq_mul.unpack_bigint(cipher)
decrypted_byte_message_int = pyrsa_sq_mul.square_multiply(cipher_int, rsakey.d, rsakey.n)
decrypted_byte_message_str = pyrsa_sq_mul.pack_bigint(decrypted_byte_message_int)
elif state == 'part3':
cipher_rsa = PKCS1_OAEP.new(rsakey)
decrypted_byte_message_str = cipher_rsa.decrypt(cipher)
return decrypted_byte_message_str
def encrypt_RSA(public_key_file, message, state='sm'):
key = open(public_key_file,'r').read()
rsakey = RSA.importKey(key)
if state == 'sm':
if isinstance(message, int):
byte_message_int = message
else:
byte_message_int = pyrsa_sq_mul.unpack_bigint(message)
encrypt_byte_message_int = pyrsa_sq_mul.square_multiply(byte_message_int, rsakey.e, rsakey.n)
encrypt_byte_message_str = pyrsa_sq_mul.pack_bigint(encrypt_byte_message_int)
elif state == 'part3':
cipher_rsa = PKCS1_OAEP.new(rsakey)
encrypt_byte_message_str = cipher_rsa.encrypt(message)
return encrypt_byte_message_str
if __name__ == "__main__":
'''Part II: Protocol Attack - Demo encryption and decryption of RSA.'''
HOST = '10.12.214.190'
PORT = 8888
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
sock.connect((HOST, PORT))
'''
For the first part I am Eve
I will impersonate Alice and send x (message), s (signature)
Bob already has Alice's public key, public key(e)
'''
print('I AM EVE FOR THIS ROUND\n')
s = 100 #2019 # 111 11100011
x = encrypt_RSA('mykey.pem.pub', pyrsa_sq_mul.pack_bigint(s))
print('Result of encryption with public key:\n{}\n'.format(x))
print('Result of encryption with public key:\n{}\n'.format(
b64encode(x)))
# Send x length
sock.send(len(x).to_bytes(4, 'big'))
print('Sent x length: {}'.format(len(x)))
# Send x
sock.sendall(x)
print('Sent new message x')
# Send s
sock.send(len(pyrsa_sq_mul.pack_bigint(s)).to_bytes(4, 'big'))
sock.sendall(pyrsa_sq_mul.pack_bigint(s))
print('Sent signature s: {}'.format(s))
# Receive acknowledgement from partner
## Receive the length of the message