class KSIServer:
"""
The KSI server.
It receive, check and sign time stamping requests.
User certificates are kept in a dict for the moment (on the long term they should be kept in a database).
A dict of all signed requests is kept (self.signed) as a dict indexed with the signed message and with the signature
as value.
"""
def __init__(self,
ID_S: Identifier,
dao: DAOServer,
filename_private_key: str = "output/private_key." +
SIGN_KEY_FORMAT):
"""
Instantiate a server object.
:param ID_S: The server's identifier
:type ID_S: Identifier
:param filename_private_key: The file containing the server's private key (used to sign)
:type filename_private_key: str
:param dao: DAO for the server
:type dao: DAOServer
"""
assert isinstance(ID_S, Identifier) and isinstance(dao, DAOServer)
assert isinstance(filename_private_key, str)
self.ID_S = ID_S
self.dao = dao
self.signer = SignVerify()
self.logger = logging.getLogger(__name__ + '.' +
self.__class__.__name__)
try:
self.signer.import_private_keys(filename_private_key)
logging.debug(
"Using private key in file '{}'".format(filename_private_key))
except FileNotFoundError:
self.logger.error(
"%s does not exist, generating and exporting keys",
filename_private_key)
self.signer.generate_keys()
filename_public_key = filename_private_key.replace(
"private", "public", 1)
self.signer.export_keys(filename_public_key, filename_private_key)
@benchmark_decorator
def get_timestamp_response(self, request: TimestampRequest,
callback) -> Signature:
"""
Send a timestamp response for a given request, check if the fields of TimestampRequest object are valid.
:param request: The request to answer to
:type request: TimestampRequest
:param callback: The function to callback once the TimestampResponse is computed.
This callback have the following signature: callback(response: TimestampResponse) -> Signature
:return: The Signature object returned by the callback
:rtype: Signature
"""
assert isinstance(request, TimestampRequest)
self.logger.info("Received timestamp request: %s", str(request))
t = datetime.utcnow().replace(
microsecond=0) # We take the time at the reception of the request
status_code = self.__client_certificate_is_valid__(request.ID_C, t)
response = TimestampResponse(request.x, self.ID_S, request.ID_C, t,
status_code)
if status_code is KSIErrorCodes.NO_ERROR:
msg, response = self.signer.sign(response)
assert self.dao.publish_signed_request(msg, response)
self.logger.info("Responding with St: %s", str(response))
return callback(response)
@benchmark_decorator
def __client_certificate_is_valid__(
self, ID_C: Identifier, current_time: datetime) -> KSIErrorCodes:
"""
Check if the client identified by ID_C have a valid certificate.
:param ID_C: The client identifier to match to the server's database of user certificates
:type ID_C: Identifier
:param current_time: The current time (at which the time stamping request was received)
:type current_time: datetime
:return: KSIErrorCodes.NO_ERROR if the certificate for ID_C is valid, KSIErrorCodes.CERTIFICATE_EXPIRED if the
client certificate expired or KSIErrorCodes.UNSPECIFIED_ERROR for other unexpected error(s)
:rtype: KSIErrorCodes
"""
assert isinstance(ID_C, Identifier) and isinstance(
current_time, datetime)
res = KSIErrorCodes.UNSPECIFIED_ERROR
cert = None
try:
cert = self.dao.get_user_certificate(ID_C)
except KeyError:
res = KSIErrorCodes.UNKNOWN_CERTIFICATE
if cert:
if cert.id_server == self.ID_S:
if current_time < cert.t_0:
res = KSIErrorCodes.CERTIFICATE_TOO_EARLY
elif current_time <= cert.t_0 + timedelta(seconds=cert.l):
res = KSIErrorCodes.NO_ERROR
else:
res = KSIErrorCodes.CERTIFICATE_EXPIRED
return res
LOGGER_DEFAULT_OUTFILE = LOGGER_DIR + LOGGER_NAME + '.log'
LOGGER_SAVE_OUTFILE = LOGGER_DIR + 'benchmark-{}-{}-{}.log'
if __name__ == '__main__':
assert PERFORM_BENCHMARKS is True # This switch need to be enabled!
assert BENCHMARK_MOTIF == "ksi.signverify"
add_logger()
logging.basicConfig(level=logging.INFO)
hash = hash_factory(data=b'ABCD')
for i in [1024, 2048, 4096]:
open(LOGGER_DEFAULT_OUTFILE, 'w+').close()
signer = SignVerify()
signer.generate_keys(i)
resp = TimestampResponse(hash, Identifier('server'), Identifier('client'), datetime.utcnow(),
KSIErrorCodes.NO_ERROR)
# Benchmark start
m, sig = signer.sign(resp)
assert signer.verify(m, sig) is True
# Benchmark end
logger = logging.getLogger(LOGGER_NAME)
for h in logger.handlers:
h.flush()
logger.removeHandler(h)
os.rename(LOGGER_DEFAULT_OUTFILE, LOGGER_SAVE_OUTFILE.format('Sign', '', 'key-len_' + str(i)))
class KSIServer:
"""
The KSI server.
It receive, check and sign time stamping requests.
User certificates are kept in a dict for the moment (on the long term they should be kept in a database).
A dict of all signed requests is kept (self.signed) as a dict indexed with the signed message and with the signature
as value.
"""
def __init__(self, ID_S: Identifier, dao: DAOServer, filename_private_key: str="output/private_key."+SIGN_KEY_FORMAT):
"""
Instantiate a server object.
:param ID_S: The server's identifier
:type ID_S: Identifier
:param filename_private_key: The file containing the server's private key (used to sign)
:type filename_private_key: str
:param dao: DAO for the server
:type dao: DAOServer
"""
assert isinstance(ID_S, Identifier) and isinstance(dao, DAOServer)
assert isinstance(filename_private_key, str)
self.ID_S = ID_S
self.dao = dao
self.signer = SignVerify()
self.logger = logging.getLogger(__name__ + '.' + self.__class__.__name__)
try:
self.signer.import_private_keys(filename_private_key)
logging.debug("Using private key in file '{}'".format(filename_private_key))
except FileNotFoundError:
self.logger.error("%s does not exist, generating and exporting keys", filename_private_key)
self.signer.generate_keys()
filename_public_key = filename_private_key.replace("private", "public", 1)
self.signer.export_keys(filename_public_key, filename_private_key)
@benchmark_decorator
def get_timestamp_response(self, request: TimestampRequest, callback) -> Signature:
"""
Send a timestamp response for a given request, check if the fields of TimestampRequest object are valid.
:param request: The request to answer to
:type request: TimestampRequest
:param callback: The function to callback once the TimestampResponse is computed.
This callback have the following signature: callback(response: TimestampResponse) -> Signature
:return: The Signature object returned by the callback
:rtype: Signature
"""
assert isinstance(request, TimestampRequest)
self.logger.info("Received timestamp request: %s", str(request))
t = datetime.utcnow().replace(microsecond=0) # We take the time at the reception of the request
status_code = self.__client_certificate_is_valid__(request.ID_C, t)
response = TimestampResponse(request.x, self.ID_S, request.ID_C, t, status_code)
if status_code is KSIErrorCodes.NO_ERROR:
msg, response = self.signer.sign(response)
assert self.dao.publish_signed_request(msg, response)
self.logger.info("Responding with St: %s", str(response))
return callback(response)
@benchmark_decorator
def __client_certificate_is_valid__(self, ID_C: Identifier, current_time: datetime) -> KSIErrorCodes:
"""
Check if the client identified by ID_C have a valid certificate.
:param ID_C: The client identifier to match to the server's database of user certificates
:type ID_C: Identifier
:param current_time: The current time (at which the time stamping request was received)
:type current_time: datetime
:return: KSIErrorCodes.NO_ERROR if the certificate for ID_C is valid, KSIErrorCodes.CERTIFICATE_EXPIRED if the
client certificate expired or KSIErrorCodes.UNSPECIFIED_ERROR for other unexpected error(s)
:rtype: KSIErrorCodes
"""
assert isinstance(ID_C, Identifier) and isinstance(current_time, datetime)
res = KSIErrorCodes.UNSPECIFIED_ERROR
cert = None
try:
cert = self.dao.get_user_certificate(ID_C)
except KeyError:
res = KSIErrorCodes.UNKNOWN_CERTIFICATE
if cert:
if cert.id_server == self.ID_S:
if current_time < cert.t_0:
res = KSIErrorCodes.CERTIFICATE_TOO_EARLY
elif current_time <= cert.t_0 + timedelta(seconds=cert.l):
res = KSIErrorCodes.NO_ERROR
else:
res = KSIErrorCodes.CERTIFICATE_EXPIRED
return res