# Simple OAuth2 with Password and Bearer { #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` { #get-the-username-and-password }

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

Sebastián Ramírez <******@****.***> 1731896744 +0100

* Imponer seguridad, autenticación, requisitos de roles, etc.
* Y muchas otras cosas...

Todo esto, mientras minimizas la repetición de código.

## Primeros Pasos

Veamos un ejemplo muy simple. Será tan simple que no es muy útil, por ahora.

Pero de esta manera podemos enfocarnos en cómo funciona el sistema de **Inyección de Dependencias**.

### Crear una dependencia, o "dependable"

        return args;
    }

    @Override
    public String getMessage() {
        return message;
    }

    /**
     * Returns a simple message without a message code.
     *
     * @return simple message without message code
     */
    public final String getSimpleMessage() {
        return simpleMessage;
    }

*.pbxproj
*.xcworkspace
/*.podspec
/tensorflow/lite/**/coreml/**/BUILD
/tensorflow/lite/**/ios/BUILD
/tensorflow/lite/**/objc/BUILD
/tensorflow/lite/**/swift/BUILD
/tensorflow/lite/examples/ios/simple/data/*.tflite
/tensorflow/lite/examples/ios/simple/data/*.txt
Podfile.lock
Pods

* external APIs
* authentication and authorization systems
* API usage monitoring systems
* response data injection systems
* etc.

## Simple and Powerful { #simple-and-powerful }

Although the hierarchical dependency injection system is very simple to define and use, it's still very powerful.

You can define dependencies that in turn can define dependencies themselves.

Apart from all the fancy words used here, the **Dependency Injection** system is quite simple.

Just functions that look the same as the *path operation functions*.

But still, it is very powerful, and allows you to declare arbitrarily deeply nested dependency "graphs" (trees).

/// tip

All this might not seem as useful with these simple examples.

But you will see how useful it is in the chapters about **security**.

* (Optionnellement) comprendre ce que vous, en tant que développeur, devez savoir sur HTTPS.
* Configurer un cluster en mode Docker Swarm avec HTTPS automatique, même sur un simple serveur à 5 dollars US/mois. En environ **20 min**.
* Générer et déployer une application **FastAPI** complète, en utilisant votre cluster Docker Swarm, avec HTTPS, etc. En environ **10 min**.

     * @param simpleMessage
     *            Simple message with arguments expanded
     * @return Message with message code
     */
    public static String getFormattedMessage(final String messageCode, final String simpleMessage) {
        return "[" + messageCode + "]" + simpleMessage;
    }

    /**
     * Expands arguments and returns a simple message without a message code.
     *
     * @param messageCode

 * interfere with session-based authentication schemes that require cookies.
 *
 * As persistence, implementations of this interface must also provide storage of cookies. Simple
 * implementations may store cookies in memory; sophisticated ones may use the file system or
 * database to hold accepted cookies. The [cookie storage model][rfc_6265_53] specifies policies for
 * updating and expiring cookies.