## Obtenir `username` et `password` { #get-the-username-and-password }

Nous allons utiliser les utilités de sécurité de **FastAPI** pour obtenir `username` et `password`.

OAuth2 spécifie que lorsqu'on utilise le « password flow » (ce que nous utilisons), le client/utilisateur doit envoyer des champs `username` et `password` en tant que données de formulaire.

## Obtenha o `username` e a `password` { #get-the-username-and-password }

É utilizado o utils de segurança da **FastAPI** para obter o `username` e a `password`.

OAuth2 especifica que ao usar o "password flow" (fluxo de senha), que estamos usando, o cliente/usuário deve enviar os campos `username` e `password` como dados do formulário.

    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.

object Credentials {
  /** Returns an auth credential for the Basic scheme. */
  @JvmStatic @JvmOverloads
  fun basic(
    username: String,
    password: String,
    charset: Charset = ISO_8859_1,
  ): String {
    val usernameAndPassword = "$username:$password"
    val encoded = usernameAndPassword.encode(charset).base64()
    return "Basic $encoded"
  }

```Python
UserInDB(**user_dict)
```

就会生成如下结果：

```Python
UserInDB(
    username="john",
    password="secret",
    email="******@****.***",
    full_name=None,
)
```

或更精准，直接使用 `user_dict`（无论它将来包含什么字段）：

```Python
UserInDB(
    username = user_dict["username"],
    password = user_dict["password"],
    email = user_dict["email"],
    full_name = user_dict["full_name"],
)

        final SystemHelper systemHelper = ComponentUtil.getSystemHelper();
        final String username = systemHelper.getUsername();
        final long currentTime = systemHelper.getCurrentTimeAsLong();
        return getEntity(form, username, currentTime).map(entity -> {
            entity.setUpdatedBy(username);
            entity.setUpdatedTime(currentTime);

from fastapi import FastAPI

app = FastAPI(swagger_ui_parameters={"syntaxHighlight": False})


@app.get("/users/{username}")
async def read_user(username: str):

from fastapi import FastAPI

app = FastAPI(swagger_ui_parameters={"deepLinking": False})


@app.get("/users/{username}")
async def read_user(username: str):

        return {"msg": "Create an account first"}
    return {"username": credentials.username, "password": credentials.password}


client = TestClient(app)


def test_security_http_basic():
    response = client.get("/users/me", auth=("john", "secret"))
    assert response.status_code == 200, response.text
    assert response.json() == {"username": "john", "password": "secret"}

{* ../../docs_src/request_forms/tutorial001_an_py310.py hl[9] *}

例如，在 OAuth2 规范的一种使用方式（称为“密码流”）中，要求将 `username` 和 `password` 作为表单字段发送。

<dfn title="规范">规范</dfn>要求这些字段必须精确命名为 `username` 和 `password`，并且作为表单字段发送，而不是 JSON。

使用 `Form` 可以像使用 `Body`（以及 `Query`、`Path`、`Cookie`）一样声明相同的配置，包括校验、示例、别名（例如将 `username` 写成 `user-name`）等。

/// info

`Form` 是直接继承自 `Body` 的类。

///

/// tip