def _helper_test_encrypt_decrypt(self,
key: bytes,
nonce: bytes,
block_counter: bytes,
rounds: int,
plaintext: bytes,
ciphertext: bytes):
encryptor = salsa20.Salsa20(key, nonce, block_counter, rounds)
decryptor = salsa20.Salsa20(key, nonce, block_counter, rounds)
encrypted = encryptor.encrypt(plaintext)
decrypted = decryptor.decrypt(encrypted)
self.assertEqual(ciphertext, encrypted)
self.assertEqual(plaintext, decrypted)
print(f'\ndecrypted: {decrypted.decode("utf-8")}')
def __call__(self, data):
iv = secrets.token_bytes(4)
inner = mode_normal()(data)
return (
b'E' + bin.uint8_t(len(self.keyname)) # key_name_length
+ self.keyname # key_name
+ bin.uint8_t(len(iv)) # iv_length
+ iv # iv
+ b'S' # type
+
salsa20.Salsa20(salsa20_keys[self.keyname], iv, 20).encrypt(inner))
def challenge_distinguisher():
coin = ord(os.urandom(1)[0]) % 2
ctxt_blocks = []
if coin == 0:
#print "THIS ACTUALLY IS A SALSA"
# salsa bytes
sk = os.urandom(32)
# initialization vector (nonce)
iv = 0
for i in range(B):
salsa = salsa20.Salsa20(sk, pack("<Q", iv), r)
ctxt = salsa.encrypt('\x00' * 64)
ctxt_blocks.append(ctxt)
iv += 1
else:
#print "NOT SALSA"
# random bytes
for i in range(B):
ctxt_blocks.append(os.urandom(64))
if distinguish(ctxt_blocks) == coin:
return True
return False
def data_to(self, data):
iv = os.urandom(8)
m_data = pickle.dumps(data)
sal = salsa20.Salsa20(self.enc_key, iv, 20)
s_data = sal.encrypt(m_data)
return iv + s_data
def data_from(self, data):
iv = data[:8]
sal = salsa20.Salsa20(self.enc_key, iv, 20)
s_data = sal.decrypt(data[8:])
m_data = pickle.loads(s_data)
return m_data