/** The key of the message: Username */
    public static final String LABELS_user_name = "{labels.user_name}";

    /** The key of the message: Login */
    public static final String LABELS_LOGIN = "{labels.login}";

    /** The key of the message: Username */
    public static final String LABELS_LOGIN_placeholder_username = "{labels.login.placeholder_username}";

Harshavardhana <******@****.***> 1622223187 -0700

        if (isTargetUser(username)) {
            executeCommand(deleteCommand, username, StringUtil.EMPTY);
        }
    }

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

        //    <proxy>
        //      <active>true</active>
        //      <protocol>http</protocol>
        //      <host>proxy.somewhere.com</host>
        //      <port>8080</port>
        //      <username>proxyuser</username>
        //      <password>somepassword</password>
        //      <nonProxyHosts>www.google.com|*.somewhere.com</nonProxyHosts>
        //    </proxy>
        //  </proxies>

When `authenticate_user` is called with a username that doesn't exist in the database, we still run `verify_password` against a dummy hash.

This ensures the endpoint takes roughly the same amount of time to respond whether the username is valid or not, preventing **timing attacks** that could be used to enumerate existing usernames.

/// note

## `username`과 데이터 형태 검증하기 { #verify-the-username-and-data-shape }

`username`을 얻었는지 확인하고, 스코프를 추출합니다.

그런 다음 Pydantic 모델로 데이터를 검증합니다(`ValidationError` 예외를 잡습니다). JWT 토큰을 읽거나 Pydantic으로 데이터를 검증하는 과정에서 오류가 나면, 앞에서 만든 `HTTPException`을 raise합니다.

이를 위해 Pydantic 모델 `TokenData`에 새 속성 `scopes`를 추가합니다.

Pydantic으로 데이터를 검증하면, 예를 들어 스코프가 정확히 `str`의 `list`이고 `username`이 `str`인지 등을 보장할 수 있습니다.

        String username = null;
        FessUserNotFoundException exception = new FessUserNotFoundException(username);

        assertNotNull(exception);
        assertEquals("User is not found: null", exception.getMessage());
        assertNull(exception.getCause());
    }

    @Test
    public void test_constructor_withSpecialCharacters() {
        // Test with username containing special characters

    }

    /**
     * Get the username used to access the repository.
     *
     * @return username at repository
     */
    public String getUsername() {
        return username;
    }

    /**
     * Set username used to access the repository.
     *
     * @param userName the username used to access repository
     */
    public void setUsername(final String userName) {
        this.username = userName;
    }

    * It contains the `username` and `password` sent.

{* ../../docs_src/security/tutorial006_an_py310.py hl[4,8,12] *}

When you try to open the URL for the first time (or click the "Execute" button in the docs) the browser will ask you for your username and password:

<img src="/img/tutorial/security/image12.png">

## Check the username { #check-the-username }

Here's a more complete example.

def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        verify_password(password, DUMMY_HASH)
        return False