def get_token(data):
''' Call a Remote TimeStamper to obtain a ts token of data '''
tst = None
tsa_url = None
with open(settings.tsa_yaml()) as tsa_list_fh:
tsa_list = yaml.load(tsa_list_fh, Loader=yaml.FullLoader)
for tsa in tsa_list:
tsa_pathfile = os.path.join(settings.path_tsa_dir(), tsa['tsacrt'])
if not os.path.isfile(tsa_pathfile):
msg = "TSA cert file missing for %s" % tsa['url']
logging.info(msg)
continue
with open(tsa_pathfile, 'rb') as tsa_fh:
certificate = tsa_fh.read()
timestamper = RemoteTimestamper(
tsa['url'],
certificate=certificate,
cafile=tsa['cacrt'],
hashname=tsa['hashname'],
timeout=tsa['timeout'],
username=tsa['username'],
password=tsa['password'],
include_tsa_certificate=tsa['include_tsa_cert'])
nonce = unpack('<q', os.urandom(8))[0]
msg = "try using TSA endpoint %s to timestamp data" % tsa['url']
logging.debug(msg)
try:
tst = timestamper.timestamp(data=data, nonce=nonce)
# TODO: does the timestamp method compare result with current datetime?
# rfc3161ng.get_timestamp(tst) must be very close to current datetime
except RuntimeError as err:
logging.debug(err)
except InvalidSignature:
msg = "Invalid signature in timestamp from %s" % tsa['url']
logging.info(msg)
else:
tsa_url = tsa['url']
break
if tst is not None:
msg = "TSA %s timestamped dataobject at: %s" % (tsa_url,
get_timestamp(tst))
logging.info(msg)
return (tst, get_timestamp(tst), tsa_url)
msg = "none of the TSA provided a timestamp"
logging.critical(msg)
return (None, None, None)
def default_test(tsa_server,
certificate,
username=None,
password=None,
data='xx',
nonce=None,
**kwargs):
with open(certificate, 'rb') as f:
certificate_data = f.read()
kwargs.update({
'certificate': certificate_data,
})
if username and password:
kwargs.update({
'username': username,
'password': password,
})
timestamper = rfc3161ng.RemoteTimestamper(tsa_server, **kwargs)
kwargs = {}
if nonce:
kwargs['nonce'] = nonce
value = timestamper(data=data, **kwargs)
assert value is not False
assert isinstance(rfc3161ng.get_timestamp(value), datetime.datetime)
assert value is not None
def get_info(tst):
''' Fetch timestamp and TSA info from token '''
return (get_timestamp(tst), get_tsa_common_name(tst))