Root Zanli
Home
Console
Upload
information
Create File
Create Folder
About
Tools
:
/
opt
/
gsutil
/
third_party
/
pyu2f
/
pyu2f
/
Filename :
hardware.py
back
Copy
# Copyright 2016 Google Inc. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """This module implements the low level device API. This module exposes a low level SecurityKey class, representing the physical security key device. """ import logging from pyu2f import apdu from pyu2f import errors class SecurityKey(object): """Low level api for talking to a security key. This class implements the low level api specified in FIDO U2F for talking to a security key. """ def __init__(self, transport): self.transport = transport self.use_legacy_format = False self.logger = logging.getLogger('pyu2f.hardware') def CmdRegister(self, challenge_param, app_param): """Register security key. Ask the security key to register with a particular origin & client. Args: challenge_param: Arbitrary 32 byte challenge string. app_param: Arbitrary 32 byte applciation parameter. Returns: A binary structure containing the key handle, attestation, and a signature over that by the attestation key. The precise format is dictated by the FIDO U2F specs. Raises: TUPRequiredError: A Test of User Precense is required to proceed. ApduError: Something went wrong on the device. """ self.logger.debug('CmdRegister') if len(challenge_param) != 32 or len(app_param) != 32: raise errors.InvalidRequestError() body = bytearray(challenge_param + app_param) response = self.InternalSendApdu(apdu.CommandApdu( 0, apdu.CMD_REGISTER, 0x03, # Per the U2F reference code tests 0x00, body)) response.CheckSuccessOrRaise() return response.body def CmdAuthenticate(self, challenge_param, app_param, key_handle, check_only=False): """Attempt to obtain an authentication signature. Ask the security key to sign a challenge for a particular key handle in order to authenticate the user. Args: challenge_param: SHA-256 hash of client_data object as a bytes object. app_param: SHA-256 hash of the app id as a bytes object. key_handle: The key handle to use to issue the signature as a bytes object. check_only: If true, only check if key_handle is valid. Returns: A binary structure containing the key handle, attestation, and a signature over that by the attestation key. The precise format is dictated by the FIDO U2F specs. Raises: TUPRequiredError: If check_only is False, a Test of User Precense is required to proceed. If check_only is True, this means the key_handle is valid. InvalidKeyHandleError: The key_handle is not valid for this device. ApduError: Something else went wrong on the device. """ self.logger.debug('CmdAuthenticate') if len(challenge_param) != 32 or len(app_param) != 32: raise errors.InvalidRequestError() control = 0x07 if check_only else 0x03 body = bytearray(challenge_param + app_param + bytearray([len(key_handle)]) + key_handle) response = self.InternalSendApdu(apdu.CommandApdu( 0, apdu.CMD_AUTH, control, 0x00, body)) response.CheckSuccessOrRaise() return response.body def CmdVersion(self): """Obtain the version of the device and test transport format. Obtains the version of the device and determines whether to use ISO 7816-4 or the U2f variant. This function should be called at least once before CmdAuthenticate or CmdRegister to make sure the object is using the proper transport for the device. Returns: The version of the U2F protocol in use. """ self.logger.debug('CmdVersion') response = self.InternalSendApdu(apdu.CommandApdu( 0, apdu.CMD_VERSION, 0x00, 0x00)) if not response.IsSuccess(): raise errors.ApduError(response.sw1, response.sw2) return response.body def CmdBlink(self, time): self.logger.debug('CmdBlink') self.transport.SendBlink(time) def CmdWink(self): self.logger.debug('CmdWink') self.transport.SendWink() def CmdPing(self, data): self.logger.debug('CmdPing') return self.transport.SendPing(data) def InternalSendApdu(self, apdu_to_send): """Send an APDU to the device. Sends an APDU to the device, possibly falling back to the legacy encoding format that is not ISO7816-4 compatible. Args: apdu_to_send: The CommandApdu object to send Returns: The ResponseApdu object constructed out of the devices reply. """ response = None if not self.use_legacy_format: response = apdu.ResponseApdu(self.transport.SendMsgBytes( apdu_to_send.ToByteArray())) if response.sw1 == 0x67 and response.sw2 == 0x00: # If we failed using the standard format, retry with the # legacy format. self.use_legacy_format = True return self.InternalSendApdu(apdu_to_send) else: response = apdu.ResponseApdu(self.transport.SendMsgBytes( apdu_to_send.ToLegacyU2FByteArray())) return response