import os
import ujson
from rsa.key import PrivateKey
# this class holds a private RSA key and a configuration for the device
# the configuraion is stored to a file
class Config:
# loads a configuraion from the specified file,
# and initializes an instance of Config
def __init__(self, config_filename, key_filename):
self.filename = config_filename
self.values = self.load_config(config_filename)
self.key = self.load_key(key_filename)
# returns a value of the specified parameter if the parameter exists
# otherwise, returns an empty string
def get(self, name):
if name in self.values:
return self.values[name]
return ''
# updates the specified parameter
def set(self, name, value):
self.values[name] = value
# stores the configuraion to the specified file
def store(self):
with open(self.filename, 'w') as f:
f.write(ujson.dumps(self.values))
# returns the private key
def private_rsa_key(self):
return self.key
# loads a configration from the specified file
def load_config(self, config_filename):
if not config_filename in os.listdir():
print('cannot find ' + config_filename)
return {}
with open(config_filename) as f:
return ujson.load(f)
# loads a private RSA key from a json file
def load_key(self, filename):
if not filename in os.listdir():
print('cannot find ' + filename)
return
with open(filename) as f:
return PrivateKey.load_pkcs1(f.read())
