python 實現 身份驗證+授權接口

import hashlib


class AuthException(Exception):
    def __init__(self, username, user=None):
        super().__init__(username, user)
        self.username = username
        self.user = user


class UsernameAlreadyExists(AuthException):
    pass


class PasswordTooShort(AuthException):
    pass


class InvalidUsername(AuthException):
    pass


class InvalidPassword(AuthException):
    pass


class PermissionError(Exception):
    pass


class NotLoggedInError(AuthException):
    pass


class NotPermittedError(AuthException):
    pass


class User:
    def __init__(self, username, password): # 用戶名密碼初始化，已經登錄狀態（默認是False）
        self.username = username
        self.password = self._encrypt_pw(password)
        self.is_logged_in = False

    def _encrypt_pw(self, password):
        hash_string = (self.username + password)
        hash_string = hash_string.encode("UTF-8")
        return hashlib.sha256(hash_string).hexdigest()

    def check_password(self, password):
        encrypted = self._encrypt_pw(password)
        return encrypted == self.password


class Authenticator:  # 身份驗證邏輯
    def __init__(self):
        self.users = {}

    def add_user(self, username, password):
        if username in self.users:
            raise UsernameAlreadyExists(username)
        if len(password) < 6:
            raise PasswordTooShort(username)
        self.users[username] = User(username, password)

    def login(self, username, password):
        try:
            user = self.users[username]
        except KeyError:
            raise InvalidUsername(username)
        if not user.check_password(password):
            raise InvalidPassword(username, user)
        user.is_logged_in = True
        return True

    def is_logged_in(self, username):
        if username in self.users:
                return self.users[username].is_logged_in
        return False


class Authorizor:  # 授權邏輯

    def __init__(self, authenticator):
        self.authenticator = authenticator
        self.permissions = {}

    def add_permission(self, perm_name):
        try:
            self.permissions[perm_name]
        except KeyError:
            self.permissions[perm_name] = set()  # 添加權限
        else:
            raise PermissionError("permission Exists")

    def permit_user(self, perm_name, username):
        try:
            perm_set = self.permissions[perm_name]
        except KeyError:
            raise PermissionError("Permission does not exist")
        else:
            if username not in self.authenticator.users:
                raise InvalidUsername(username)
            perm_set.add(username)

    def check_permission(self, perm_name, username):
        if not self.authenticator.is_logged_in(username):
            raise NotLoggedInError(username)
        try:
            perm_set = self.permissions[perm_name]
        except KeyError:
            raise PermissionError("Permission does not exist")
        else:
            if username not in perm_set:
                raise NotPermittedError(username)
            else:
                return True


authenticator = Authenticator()
authorizor = Authorizor(authenticator)

class Editor:  # 封裝成一個接口，方便調用
    def __init__(self):
        self.username = None
        self.menu_map = {
            "login": self.login,
            "test": self.test,
            "change": self.change,
            "quit": self.quit
                        }

    def login(self):
        logged_in = False
        while not logged_in:
            username = input("username: ")
            password = input("password: ")
            try:
                logged_in = authenticator.login(username, password)
            except InvalidUsername:
                print("Sorry, that username does not exist")
            except InvalidPassword:
                print("Sorry, incorrect password")
            else:
                self.username = username

    def is_permitted(self, permission):
        try:
            authorizor.check_permission(permission, self.username)
        except NotLoggedInError as e:
            print("{} is not logged in".format(e.username))
            return False
        except NotPermittedError as e:
            print("{} cannot {}".format(e.username, permission))
            return False
        else:
            return True

    def test(self):
        if self.is_permitted("test program"):
            print("Testing program now ...")

    def change(self):
        if self.is_permitted("change program"):
            print("Changing program now...")

    def quit(self):
        raise SystemExit()

    def menu(self):
        try:
            while True:
                print("""
                        please enter a command:
                        \tlogin\tLogin
                        \ttest\tTest the program
                        \tchange\tChange the program
                        \tquit\tQuit

                        """)
                answer = input("enter a command: ").lower()
                try:
                    func = self.menu_map[answer]
                except KeyError:
                    print("{} is not a valid option".format(answer))
                else:
                    func()
        finally:
            print("Thank you for testing thr auth module")


Editor().menu() # 運行這個即可開啟接口

# 主要是使用異常方式在處理各種情況，還可以有很多種處理方式，可以根據自己的項目來修改