onionr/onionr/timedHmac.py

44 lines
1.8 KiB
Python

'''
Onionr - P2P Microblogging Platform & Social network. Run with 'help' for usage.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
'''
import hmac, base64, time, math
class TimedHMAC:
def __init__(self, base64Key, data, hashAlgo):
'''
base64Key = base64 encoded key
data = data to hash
expire = time expiry in epoch
hashAlgo = string in hashlib.algorithms_available
Maximum of 10 seconds grace period
'''
self.data = data
self.expire = math.floor(time.time())
self.hashAlgo = hashAlgo
self.b64Key = base64Key
generatedHMAC = hmac.HMAC(base64.b64decode(base64Key).decode(), digestmod=self.hashAlgo)
generatedHMAC.update(data + expire)
self.HMACResult = generatedHMAC.hexdigest()
return
def check(self, data):
# Check a hash (and verify time is sane)
testHash = hmac.HMAC(base64.b64decode(base64Key).decode(), digestmod=self.hashAlgo)
testHash.update(data + math.floor(time.time()))
testHash = testHash.hexdigest()
if hmac.compare_digest(testHash, self.HMACResult):
return true
else:
return false