}
  }
}

suspend fun main() {
  val client = OkHttpClient()

  val scraper = SslLabsScraper(client)

  println(scraper.query())

  client.connectionPool.evictAll()
  client.dispatcher.executorService.shutdown()

But for now, let's check these important **conceptual ideas**. These concepts also apply to any other type of web API. 💡

## Security - HTTPS

In the [previous chapter about HTTPS](https.md){.internal-link target=_blank} we learned about how HTTPS provides encryption for your API.

# Get Current User

In the previous chapter the security system (which is based on the dependency injection system) was giving the *path operation function* a `token` as a `str`:

=== "Python 3.9+"

    ```Python hl_lines="12"
    {!> ../../../docs_src/security/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="11"
    {!> ../../../docs_src/security/tutorial001_an.py!}
    ```

=== "Python 3.8+ non-Annotated"

This code is something you can actually use in your application, save the password hashes in your database, etc.

We are going to start from where we left in the previous chapter and increment it.

## About JWT

JWT means "JSON Web Tokens".

It's a standard to codify a JSON object in a long dense string without spaces. It looks like this:

```

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

!!! note
    If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

## Motivation

Let's start with a simple example:

```Python
{!../../../docs_src/python_types/tutorial001.py!}
```

Calling this program outputs:

```
John Doe
```

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// https://www.eclipse.org/jetty/documentation/current/alpn-chapter.html#alpn-versions
private fun alpnBootVersionForPatchVersion(patchVersion: Int): String? {
  return when (patchVersion) {
    in 0..24 -> "8.1.0.v20141016"
    in 25..30 -> "8.1.2.v20141202"

# Simple OAuth2 with Password and Bearer

Now let's build from the previous chapter and add the missing parts to have a complete security flow.

## Get the `username` and `password`

We are going to use **FastAPI** security utilities to get the `username` and `password`.

OAuth2 specifies that when using the "password flow" (that we are using) the client/user must send a `username` and `password` fields as form data.

To see all the options you have, checkout the docs for <a href="https://docs.pydantic.dev/latest/concepts/types/" class="external-link" target="_blank">Pydantic's exotic types</a>. You will see some examples in the next chapter.

For example, as in the `Image` model we have a `url` field, we can declare it to be an instance of Pydantic's `HttpUrl` instead of a `str`:

=== "Python 3.10+"

    ```Python hl_lines="2  8"

And that function takes parameters in the same way that *path operation functions* do.

!!! tip
    You'll see what other "things", apart from functions, can be used as dependencies in the next chapter.

Whenever a new request arrives, **FastAPI** will take care of:

* Calling your dependency ("dependable") function with the correct parameters.
* Get the result from your function.

Serv-Inc, Severen Redwood, Shahzad Lone, Shashank Gupta, shashvat, Shashvat
Chand Shahi, Shubham Goyal, Shashi, Sigrid Keydana, Siju, Siju Samuel,
sleighsoft, smilu97, Snease-Abq, Son Tran, Spencer Schaber, sremedios, Srini511,
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Sungmann Cho, sunway513, Supriya Rao, sxwang, Tae-Hwan Jung, Taehoon Lee, Takeo