def _getCurrUsersPass_():
"""
Gets the current users and passwords and returns a dictionary with the users and passwords. If file doesn't exist, it creates it with admin's details
return: dict with users array (accesed by 'users' key) and passwords array (accessed by 'passwords' key)
"""
# if file doesn't exist, create file with admin details
if not os.path.exists(USERS_FILE):
ret = {'users': ["admin"], 'passwords': [ADMIN_PASS]}
saveFile(USERS_FILE,
"admin" + USER_PASS_DELIM + ADMIN_PASS + USER_DELIM)
return ret
# get users file contents
curr_users_contents = readFile(USERS_FILE)
users_passwords = curr_users_contents.split(USER_DELIM)
ret = {'users': [], 'passwords': []} # init users and pass dict
# seperate users from passwords
for userPass in users_passwords:
if not userPass: # if string is empty we're done
break
tmpArr = userPass.split(USER_PASS_DELIM)
ret['users'].append(tmpArr[0])
ret['passwords'].append(tmpArr[1])
return ret
def upload_file(self, filename, fernet):
"""
Saves and uploads an encrypted version of the file named filename, if the file exists locally and no duplicate is on the drive
param filename: Name of the file to be uploaded
param fernet: The fernet object created in KeyManagementSystem class
return: Filename of encrypted file, if file uploaded successfully, else None
"""
# add path to filename if needed
prevFilename = filename
filename = self.normaliseFilename(filename)
# return None if file doesn't exist
if not os.path.exists(filename):
print("Error 404: File specified not found")
return None
# get the drive's main folder ID
folderID = self._get_file_ID_(DRIVE_FOLDER, DRIVE_ROOT_ID)
# Create and share folder on drive if it doesnt exist, and get folderID
if folderID == None:
folderID = self.__create_share_folder__()
print("Created shared folder on drive")
# Check if file with identical name is already on the drive
encryptedFilename = prevFilename + ENCR_EXTENSION
encryptedFileID = self._get_file_ID_(encryptedFilename, folderID)
if encryptedFileID != None: # implies there's a file identically named
print("This file is already up on the drive!")
return None
# Save encrypted file locally
plain_text = readFile(filename) # getting file contents
cipher_text = GoogleDriveAccess._encrypt_(plain_text, fernet)
normEncryptedFilename = encryptedFilename
normEncryptedFilename = self.normaliseFilename(normEncryptedFilename)
saveFile(normEncryptedFilename, cipher_text) # Saving file locally
# Upload encrypted file to google drive folder
fileToUpload = self.drive.CreateFile({"title": encryptedFilename, "parents": [{"id": folderID}]})
fileToUpload.SetContentFile(normEncryptedFilename) # set file contents
fileToUpload.Upload()
# Delete local version of encrypted file here
os.remove(normEncryptedFilename)
return encryptedFilename
def save_new_users(users):
"""
Saves the new users to the relevant file, in proper format
param users: Array of new users
return: None
"""
# make content using array and delimiters
content = ""
for i in range(len(users)):
content += users[i] + USER_DELIM
# save the file
saveFile(N_USERS_FILE, content)
def save_old_users(users_pass):
"""
Saves the old users to the relevant file, in proper format
param users_pass: Dictionary containg arrays of old users and passwords
return: None
"""
# make content using dictionary and delimiters
content = ""
for i in range(len(users_pass['users'])):
content += users_pass['users'][i] + USER_PASS_DELIM
content += users_pass['passwords'][i] + USER_DELIM
# save the file
saveFile(USERS_FILE, content)
def _getNewUsers_():
"""
Reads contents of the new user files and gives back an array with new usernames. Create empty file if file doesn't exist
return: Array with new usernames
"""
# Create emtpy file if it doesn't exist
if not os.path.exists(N_USERS_FILE):
saveFile(N_USERS_FILE, "")
return []
# get new user's usernames
new_users_contents = readFile(N_USERS_FILE)
new_users = new_users_contents.split(USER_DELIM)
return new_users[:-1] # ignore last empty element
def handle_new_user(username):
"""
Initialisation of a new user. Creates new folder for user files, generates private and public key and saves serialized private key, and also saves the encrypted symmetric key to user's folder, to be decrypted by the user's private key
param username: username of the new user to be initialised
return: the fernet
"""
driveAccess = GoogleDriveAccess(
username
) # This creates a folder for the user, and also gives access to the drive
# key pair generation and verification
priv_key = rsa.generate_private_key(public_exponent=65537,
key_size=2048,
backend=default_backend())
pub_key = priv_key.public_key()
# Serialization of private key for file storage
priv_bytes = priv_key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.TraditionalOpenSSL,
encryption_algorithm=serialization.NoEncryption())
# Save serialized private key to user's folder in plaintext
folder_name = username + "_files/"
filepath = folder_name + PRIV_KEY_FILE
saveFile(filepath, priv_bytes)
# encrypt (using user's pubkey) and save symmetric key to user's folder
kms = KMS()
encrypted_sym_key = pub_key.encrypt(
kms.key,
padding.OAEP(mgf=padding.MGF1(algorithm=hashes.SHA256()),
algorithm=hashes.SHA256(),
label=None))
filepath = folder_name + SHARED_KEY_FILE
saveFile(filepath, encrypted_sym_key)
# do what you do for the old user anywyay, and return the fernet it returns
return handle_old_user(username)
def __generate_new_key__(self):
"""
Generates a new key (and fernet obj) and saves it to the file
return: None
"""
# generate a key
self.key = Fernet.generate_key()
# create admin's directory if it doesn't exist
if not os.path.isdir(ADMIN_FOLDER):
os.mkdir(ADMIN_FOLDER)
# save key to appropriate file in admin's directory
saveFile(ADMIN_FOLDER + "/" + SHARED_KEY_FILE, self.key)
# create fernet object
self.fernet = Fernet(self.key) # create fernet obj
# Broadcast the new key to everyone (method in group handler class)
change_all_keys()
def download_file(self, filename, fernet):
"""
Downloads a file named filename from the drive and saves the decrypted version, if the file exists
param filename: Name of the file to be downloaded
param fernet: The fernet object created in KeyManagementSystem class
return: Filename of decrypted file, if file downloaded successfully, else None
"""
# Add encrypt extension if it's not in filename
if ENCR_EXTENSION not in filename:
filename = filename + ENCR_EXTENSION
# If drive's shared folder doesn't exist, return None
folderID = self._get_file_ID_(DRIVE_FOLDER, DRIVE_ROOT_ID)
if folderID == None:
print("Error 404: Shared folder not found on drive")
return None
# Return None if file doesnt exist on drive
fileID = self._get_file_ID_(filename, folderID)
if fileID == None:
print("Error 404: File specified does not exist on the drive")
return None
# Download encrypted file contents from google drive
downloadedFile = self.drive.CreateFile({'id': fileID})
cipher_text = downloadedFile.GetContentString()
# Get decrypted file data and save decrypted file locally
plain_text = GoogleDriveAccess._decrypt_(cipher_text.encode('utf-8'), fernet)
filename = self.normaliseFilename(filename)
decryptedFilename = filename[ : -len(ENCR_EXTENSION)]
saveFile(decryptedFilename, plain_text)
return decryptedFilename
