import time
import base64
import hmac

def generate_token(key, expire=3600):
 r'''
 @Args:
  key: str (用戶給定的key，需要用戶保存以便之后驗證token,每次產(chǎn)生token時的key 都可以是同一個key)
  expire: int(最大有效時間，單位為s)
 @Return:
  state: str
 '''
 ts_str = str(time.time() + expire)
 ts_byte = ts_str.encode("utf-8")
 sha1_tshexstr = hmac.new(key.encode("utf-8"),ts_byte,'sha1').hexdigest() 
 token = ts_str+':'+sha1_tshexstr
 b64_token = base64.urlsafe_b64encode(token.encode("utf-8"))
 return b64_token.decode("utf-8")

import time
import base64
import hmac

def certify_token(key, token):
 r'''
 @Args:
  key: str
  token: str
 @Returns:
  boolean
 '''
 token_str = base64.urlsafe_b64decode(state).decode('utf-8')
 token_list = token_str.split(':')
 if len(token_list) != 2:
 return False
 ts_str = token_list[0]
 if float(ts_str) < time.time():
 # token expired
 return False
 known_sha1_tsstr = token_list[1]
 sha1 = hmac.new(key.encode("utf-8"),ts_str.encode('utf-8'),'sha1')
 calc_sha1_tsstr = sha1.hexdigest()
 if calc_sha1_tsstr != known_sha1_tsstr:
 # token certification failed
 return False 
 # token certification success
 return True 

key = "JD98Dskw=23njQndW9D"
# 一小時后過期
token = generate_token(key, 3600)

certify_token(key, token)