def calculate(self,
slot,
challenge=None,
totp=False,
digits=6,
wait_for_touch=True):
if totp:
if challenge is None:
challenge = time_challenge(time.time())
else:
challenge = time_challenge(challenge)
else:
challenge = a2b_hex(challenge)
resp = create_string_buffer(64)
# Some versions of the NEO firmware returns error 11 too often.
# Give the YubiKey 10 tries to do the calculation.
for idx in range(10):
try:
check(
ykpers.yk_challenge_response(self._dev,
SLOTS[slot], wait_for_touch,
len(challenge), challenge,
sizeof(resp), resp))
except YkpersError as e:
if idx < 10 and e.errno == 11 and wait_for_touch is True:
# Error 11 when wait_for_touch is true is an unexpected
# state, let's try again.
continue
else:
raise
if totp:
return format_code(parse_totp_hash(resp.raw[:20]), digits)
else:
return b2a_hex(resp.raw[:20])
def test_time_challenge(self):
self.assertEqual(b'\0' * 8, time_challenge(0))
self.assertEqual(b'\x00\x00\x00\x00\x00\x06G\x82',
time_challenge(12345678))
self.assertEqual(b'\x00\x00\x00\x00\x02\xf2\xeaC',
time_challenge(1484223461.2644958))