import time import datetime import math import hmac import base64 from hashlib import sha1 class GoogleAuthenticator(object): def __init__(self,secretKey=None,digits=6,interval=30): self.secretKey = secretKey self.digits = digits self.interval = interval def __str_extend(self,old_str,length,extend_str): new_strs = None if len(old_str) < length: clen = length - len(old_str) s0 = ''.join([extend_str for i in range(clen)]) new_strs = s0 + old_str elif len(old_str) == length: new_strs = old_str return new_strs def __str_split(self,old_str,split_len,prefix='',suffix=''): array = [] str_len = len(old_str) for i in range(0,str_len,4): if i + 4 < str_len: array.append(prefix+old_str[i:i+4]+suffix) else: array.append(prefix+old_str[i:str_len]+suffix) return array def __base32tohex(self,base32str): base32chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567" bits = "" for i in range(len(base32str)): char = str(base32str[i]).upper() idx = int(base32chars.index(char)) bit = self.__str_extend(format(idx,'b'),5,'0') if bit is None: raise Exception('bit={},len={}'.format(bit,len(bit))) bits += bit bitArray = self.__str_split(bits,4,'0b') hexstr = ''.join([format(int(i,2),'x') for i in bitArray]) return hexstr def __get_HexSecret(self): hexstr = self.__base32tohex(self.secretKey) return hexstr def __byte_secret(self): missing_padding = len(self.secretKey) % 8 if missing_padding != 0: self.secret += '=' * (8 - missing_padding) return base64.b32decode(self.secretKey, casefold=True) def __int_to_bytestring(self,i, padding=8): result = bytearray() while i != 0: result.append(i & 0xFF) i >>= 8 return bytes(bytearray(reversed(result)).rjust(padding, b'\0')) def __timecode(self, for_time): i = time.mktime(for_time.timetuple()) return int(i / self.interval) def get_QR_url(self): QR_url = "https://chart.googleapis.com/chart?chs=200x200&cht=qr&chl=200x200&chld=M|0&cht=qr&chl=otpauth://totp/[email protected]\%3Fsecret%3D" + self.secretKey return QR_url def getTotp(self): key = self.secretKey timestamp = self.__timecode(datetime.datetime.now()) hasher = hmac.new(self.__byte_secret(), self.__int_to_bytestring(timestamp), sha1) # print(hasher.hexdigest()) hmac_hash = bytearray(hasher.digest()) offset = hmac_hash[-1] & 0xf code = ((hmac_hash[offset] & 0x7f) << 24 | (hmac_hash[offset + 1] & 0xff) << 16 | (hmac_hash[offset + 2] & 0xff) << 8 | (hmac_hash[offset + 3] & 0xff)) str_code = str(code % 10 ** self.digits) while len(str_code) < self.digits: str_code = '0' + str_code return str_code def verifyTotp(self,str_code): gTotp = self.getTotp() if gTotp == str_code: return True else: return False