def sign(self, message: bytes, use_rest_api=False) -> Signature:
"""
Ask the server to sign the message.
At the end of this function self.requests will contain an entry at x for self.sign_callback().
:param message: The message to sign
:type message: bytes
:param use_rest_api: Set to True if you want to use the remote REST API, False otherwise (e.g. travis)
:type use_rest_api: bool
:return: The signature returned by the self.sign_callback()
:rtype: Signature
"""
assert isinstance(message, bytes) and isinstance(use_rest_api, bool)
current_time = datetime.utcnow().replace(microsecond=0)
self.logger.debug("Sign request at %s for message: %s",
current_time.isoformat(), message)
# Assert we have a z_i to sign this message
if not (current_time <
self.certificate.t_0 + timedelta(seconds=self.keys.l)):
self.logger.error("Attempt to sign with an outdated certificate!")
raise ValueError
# Compute the time difference between now and t_0 of the certificate
time_delta = current_time - self.certificate.t_0 # type: timedelta
# time_delta + 1 is meant to correct the index
time_delta_offset = int(time_delta.total_seconds()) + 1
if time_delta_offset < 0:
self.logger.error(
"Attempt to sign with a certificate beginning in the future!")
raise ValueError
# Take the appropriate z_i from the list (exclude the first item being z_0)
z_i = self.keys.keys[time_delta_offset] # type: Node
self.logger.debug("\tz_i used to sign: %s", z_i.hash.hex())
# x = hash(message || z_i)
x = hash_factory(data=bytes(message) + z_i.hash)
self.logger.debug("\tx computed: %s", x.hexdigest())
# Insert x in self.requests
self.requests[x.hexdigest()] = (z_i, time_delta_offset, x, message)
request = TimestampRequest(x.digest(), self.certificate.id_client)
# Create the request and send it to the server to get S_t
if use_rest_api:
assert self.api_user != "" and self.api_password != ""
r = requests.post(API_HOST_PORT + API_ROUTE_BASE + 'sign',
data=request.to_json(),
auth=(self.api_user, self.api_password),
headers={'Content-Type': 'application/json'})
response = TimestampResponse.from_json_dict(r.json())
return self.sign_callback(response)
else:
return self.server.get_timestamp_response(
request, lambda _response: self.sign_callback(_response))
def sign(self, message: bytes, use_rest_api=False) -> Signature:
"""
Ask the server to sign the message.
At the end of this function self.requests will contain an entry at x for self.sign_callback().
:param message: The message to sign
:type message: bytes
:param use_rest_api: Set to True if you want to use the remote REST API, False otherwise (e.g. travis)
:type use_rest_api: bool
:return: The signature returned by the self.sign_callback()
:rtype: Signature
"""
assert isinstance(message, bytes) and isinstance(use_rest_api, bool)
current_time = datetime.utcnow().replace(microsecond=0)
self.logger.debug("Sign request at %s for message: %s", current_time.isoformat(), message)
# Assert we have a z_i to sign this message
if not (current_time < self.certificate.t_0 + timedelta(seconds=self.keys.l)):
self.logger.error("Attempt to sign with an outdated certificate!")
raise ValueError
# Compute the time difference between now and t_0 of the certificate
time_delta = current_time - self.certificate.t_0 # type: timedelta
# time_delta + 1 is meant to correct the index
time_delta_offset = int(time_delta.total_seconds()) + 1
if time_delta_offset < 0:
self.logger.error("Attempt to sign with a certificate beginning in the future!")
raise ValueError
# Take the appropriate z_i from the list (exclude the first item being z_0)
z_i = self.keys.keys[time_delta_offset] # type: Node
self.logger.debug("\tz_i used to sign: %s", z_i.hash.hex())
# x = hash(message || z_i)
x = hash_factory(data=bytes(message) + z_i.hash)
self.logger.debug("\tx computed: %s", x.hexdigest())
# Insert x in self.requests
self.requests[x.hexdigest()] = (z_i, time_delta_offset, x, message)
request = TimestampRequest(x.digest(), self.certificate.id_client)
# Create the request and send it to the server to get S_t
if use_rest_api:
assert self.api_user != "" and self.api_password != ""
r = requests.post(
API_HOST_PORT + API_ROUTE_BASE + "sign",
data=request.to_json(),
auth=(self.api_user, self.api_password),
headers={"Content-Type": "application/json"},
)
response = TimestampResponse.from_json_dict(r.json())
return self.sign_callback(response)
else:
return self.server.get_timestamp_response(request, lambda _response: self.sign_callback(_response))
def from_json(json_obj: dict):
"""
:param json_obj: A JSON representation of the Signature object
:type json_obj: dict
:return: A new Signature built from the json_obj parameter
:rtype: Signature
"""
assert 'ID_C' in json_obj
assert 'i' in json_obj
assert 'z_i' in json_obj
assert 'c_i' in json_obj
assert 'msg' in json_obj
assert 'S_t' in json_obj
ID_C = Identifier(json_obj['ID_C'][len(IDENTIFIER_BASE_NAME):])
i = json_obj['i']
z_i = standard_b64decode(json_obj['z_i'])
c_i = pickle.loads(standard_b64decode(json_obj['c_i']))
msg = standard_b64decode(json_obj['msg'])
S_t = TimestampResponse.from_json_dict(json_obj['S_t'])
return Signature(ID_C, i, z_i, c_i, S_t, msg)
