* @param domain the domain for authentication
     * @param username the username for authentication
     * @param password the password for authentication
     */
    public JAASAuthenticator(String serviceName, String domain, String username, String password) {
        super(null, domain, username, password);
        this.serviceName = serviceName;
    }

    /**
     * Create an authenticator using the given credentials

            if (form.crudMode.intValue() == CrudMode.CREATE || StringUtil.isNotBlank(form.password)) {
                final String encodedPassword = ComponentUtil.getComponent(FessLoginAssist.class).encryptPassword(form.password);
                entity.setOriginalPassword(form.password);
                entity.setPassword(encodedPassword);
            }

* **input modeli** bir `password` içerebilmelidir.
* **output modeli** `password` içermemelidir.
* **database modeli** büyük ihtimalle hash'lenmiş bir `password` tutmalıdır.

/// danger | Tehlike

Kullanıcının düz metin (plaintext) `password`'ünü asla saklamayın. Her zaman sonradan doğrulayabileceğiniz "güvenli bir hash" saklayın.

     */
    void delete(User user);

    /**
     * Changes the password for the specified user.
     * @param username The username for which to change the password.
     * @param password The new password.
     * @return True if the password was successfully changed, false otherwise.
     */
    boolean changePassword(String username, String password);

    /**
     * Loads user information from the authentication chain.

# Простий OAuth2 з паролем і Bearer { #simple-oauth2-with-password-and-bearer }

Тепер продовжимо з попереднього розділу і додамо відсутні частини, щоб отримати повний потік безпеки.

## Отримайте `username` і `password` { #get-the-username-and-password }

Ми використаємо утиліти безпеки **FastAPI**, щоб отримати `username` і `password`.

    #   o user: (Required)
    #   o password: password plainly or path to password file (with default password)
    #       e.g. foo or df:dfprop/system-password.txt|foo
    #       (NotRequired - Default '')
    #   o isSkipIfNotFoundPasswordFileAndDefault: Does it skip the user SQL statement
    #       when using password file but not found it and also default password?
    #       (NotRequired - Default false)
    #

    }

    /**
     * Validates a password against configured password policy requirements.
     *
     * @param password The password to validate.
     * @return An empty string if the password is valid, or an error key for the validation failure.
     */
    public String validatePassword(final String password) {
        if (StringUtil.isBlank(password)) {
            return "errors.blank_password";
        }

# 簡易 OAuth2：Password 與 Bearer { #simple-oauth2-with-password-and-bearer }

現在從上一章延伸，補上缺少的部分，完成整個安全流程。

## 取得 `username` 與 `password` { #get-the-username-and-password }

我們要使用 **FastAPI** 提供的安全性工具來取得 `username` 與 `password`。

OAuth2 規範中，當使用「password flow」（我們現在使用的）時，用戶端／使用者必須以表單資料送出 `username` 與 `password` 欄位。

而且規範要求欄位名稱必須就是這兩個，所以像是 `user-name` 或 `email` 都不行。

但別擔心，你在前端要怎麼呈現給最終使用者都可以。

而你的資料庫模型也可以使用任何你想要的欄位名稱。

    if not user_dict:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    user = UserInDB(**user_dict)
    hashed_password = fake_hash_password(form_data.password)
    if not hashed_password == user.hashed_password:
        raise HTTPException(status_code=400, detail="Incorrect username or password")

    return {"access_token": user.username, "token_type": "bearer"}


@app.get("/users/me")

        }
    }

    @Override
    public boolean changePassword(final String username, final String password) {
        if (isTargetUser(username) && StringUtil.isNotBlank(password)) {
            return executeCommand(updateCommand, username, password) == 0;
        }
        return true;
    }

    @Override
    public User load(final User user) {
        return user;
    }

    /**