单机环境下基于口令的身份认证

import random
import string
#给口令加盐
def addsalt(salt, pw):
    print("Adding salt...")
    pw = pw + salt
    print("Salt added.")
    return hash(pw)
#加密的实现    
def ecrypt(dp, key, i):
    print("Ecrypting data using your password...(round " + str(i+1) + ")")
    for i in range(0, len(dp)):
        index = i % len(key)
        if(key[index] == ‘-‘):
            dp[i] = str(int(dp[i]) % 10)
        else:
            dp[i] = str((int(dp[i]) + int(key[index])) % 10)
    return dp
#口令字段信息的生成算法
def generate(salt, pw):
    print("Generating data ecrypted by your password...")
    #给口令Dpw 撒盐，用撒盐结果做密钥
    saltedpw = str(addsalt(salt, pw))
    dp = []
    #用一个64 位的全0 的二进制位串构造一个数据块
    for i in range(0, 64):
        dp.append(‘0‘)
    #对数据块加密
    for i in range(0, 25):
        dp = ecrypt(dp, saltedpw, i)
    print("Data ecrypted by your password generated.")
    return dp

#创建用户
def createuser(database):
    print("Creating user...")
    print("Input ‘q‘ as username if you want to quit.")
    while(1):
        name = input("username: ")
        if name == ‘q‘:
            break
        pw = input("password: ")
        salt = ‘‘.join(random.sample(string.ascii_letters + string.digits, 8))
        s = generate(salt, pw)
        dic = {}
        dic[‘name‘] = name
        dic[‘salt‘] = salt
        dic[‘pw‘] = s
        database.append(dic)
        print("User " + name + " is created.")
#直接通过字典匹配用户，检查此用户是否存在
def has_user(database, name):
    for dic in database:
        if dic[‘name‘] == name:
            return 1
    return 0
#得到用户的具体信息
def get_info(database, name):
    for dic in database:
        if dic[‘name‘] == name:
            salt = dic[‘salt‘]
            s = dic[‘pw‘]
            return salt, s
#身份认证算法
def authenticate(database):
    print("Authenticating user...")
    print("Input ‘q‘ as username if you want to quit.")
    while(1):
        #接收用户提供的账户名Dname ；
        name = input("username: ")
        if name == ‘q‘:
            break
        flag = has_user(database, name)
        if flag == 0:
            print("Sorry, user " + name + " does not exist.")
            continue
        #接受用户提供的口令
        pw = input("password: ")
        #在账户信息数据库中检查Dname 的合法性，如果合法，则找出其对
        #应的s 和Dsalt
        salt, s = get_info(database, name)
        #生成临时口令信息
        sr = generate(salt, pw)
        print("Comparing ecrypted data...")
        if(s == sr):
            print("User " + name + " authenticated.")
        else:
            print("Sorry, the password is wrong.")
database = []
createuser(database)
authenticate(database)