def test_repeat_xor_empty_key_returns_unchanged_bytes(self):
b = b'Hey'
expected_bytes = b'Hey'
actual_bytes = repeat_xor(b, b'')
self.assertEqual(expected_bytes, actual_bytes)
def test_repeat_xor_single_byte_key(self):
b = b'Hey'
key = b'A'
expected_bytes = b'\x09\x24\x38'
actual_bytes = repeat_xor(b, key)
self.assertEqual(expected_bytes, actual_bytes)
def break_repeat_xor(encrypted: bytes, keysize: int) -> list:
"""
params:
encrypted: bytes encrypted using repeat-xor
returns:
dictionary {'message': bytes, 'key': bytes} with most likely
decrypted message and key using given `keysize`
"""
key = b''
for i in range(keysize):
key += break_single_xor(build_transposed(encrypted, keysize,
i))[0]['key']
return {'message': repeat_xor(encrypted, key), 'key': key}
def test_repeat_xor_cryptopals_case(self):
b = (b"Burning 'em, if you ain't quick and nimble\n"
b"I go crazy when I hear a cymbal")
key = b"ICE"
expected_hex = ("0b3637272a2b2e63622c2e69692a23693a2a3c6324202d623d633"
"43c2a26226324272765272"
"a282b2f20430a652e2c652a3124333a653e2b2027630c692b2028"
"3165286326302e27282f")
actual_bytes = repeat_xor(b, key)
actual_hex = actual_bytes.hex()
self.assertEqual(expected_hex, actual_hex)
def test_repeat_xor_none_input_raises_typeerror(self):
with self.assertRaises(TypeError):
repeat_xor(None, b'A')
def test_repeat_xor_empty_input_returns_empty_bytes(self):
self.assertEqual(repeat_xor(b'', b'A'), b'')