用户注册和登陆系统，采用hmac加密密码

import hashlib
import pickle, os
import hmac, random


def hmac_sha1(key, s):
 return hmac.new(key.encode('utf-8'), s.encode('utf-8'), 'MD5').hexdigest()


# 获取用户名和密码信息
if os.path.exists('/Users/lewisliu/user_information.txt'):
 with open('/Users/lewisliu/user_information.txt', 'rb') as f:
 user_information = pickle.load(f)
else:
 user_information = dict()

# 注册或者登陆
while True:
 # 选择模式，注册、登陆、退出
 model = input("pleas input enroll/login/exit:")
 if model == 'enroll':
 name = input("please input your name:")
 # 用户名重复识别
 if name in user_information.keys():
 print("name is occupied!")
 continue
 password = input("please input your password:")
 # 数据库添加用户名和密码
 key = 'liu' # ''.join([chr(random.randint(48, 122)) for i in range(20)])
 user_information[name] = hmac_sha1(key, password)
 # sha1 = hashlib.sha1()
 # sha1.update(password.encode('utf-8'))
 # user_information[name] = sha1.hexdigest()
 elif model == 'login':
 name = input("please input your name:")
 if name not in user_information.keys():
 print("name is not exist!")
 continue
 password = input("please input your password:")
 key = 'liu' # ''.join([chr(random.randint(48, 122)) for i in range(20)])
 password = hmac_sha1(key, password)
 # sha1 = hashlib.sha1()
 # sha1.update(password.encode('utf-8'))
 # password = sha1.hexdigest()
 if user_information[name] == password:
 print("Wellcome!")
 else:
 print("wrong name or password! Exit!")
 with open('/Users/lewisliu/user_information.txt', 'wb') as f:
 pickle.dump(user_information, f)
 exit()
 elif model == 'exit':
 with open('/Users/lewisliu/user_information.txt', 'wb') as f:
 pickle.dump(user_information, f)
 exit()
 else:
 print("model wrong!")