# Security { #security }

There are many ways to handle security, authentication and authorization.

And it normally is a complex and "difficult" topic.

In many frameworks and systems just handling security and authentication takes a big amount of effort and code (in many cases it can be 50% or more of all the code written).

    - [Client Binaries](#client-binaries-4)
    - [Server Binaries](#server-binaries-4)
    - [Node Binaries](#node-binaries-4)
  - [Changelog since v1.20.10](#changelog-since-v12010)
  - [Important Security Information](#important-security-information)
    - [CVE-2021-25741: Symlink Exchange Can Allow Host Filesystem Access](#cve-2021-25741-symlink-exchange-can-allow-host-filesystem-access)
  - [Changes by Kind](#changes-by-kind-4)

    "/with-oauth2-scheme",
    dependencies=[Security(oauth2_scheme, scopes=["read", "write"])],
)
async def read_with_oauth2_scheme():
    return {"message": "Admin Access"}


@app.get(
    "/with-get-token", dependencies=[Security(get_token, scopes=["read", "write"])]
)
async def read_with_get_token():
    return {"message": "Admin Access"}


router = APIRouter(dependencies=[Security(oauth2_scheme, scopes=["read"])])

{* ../../docs_src/security/tutorial005_an_py310.py hl[5,9,13,47,65,106,108:116,122:126,130:136,141,157] *}

Ahora revisemos esos cambios paso a paso.

## Esquema de seguridad OAuth2 { #oauth2-security-scheme }

All the security utilities that integrate with OpenAPI (and the automatic API docs) inherit from `SecurityBase`, that's how **FastAPI** can know how to integrate them in OpenAPI.

///

        'interceptors.md': 'features/interceptors.md'
        'r8_proguard.md': 'features/r8_proguard.md'
        # Redirect all Security pages to security/*
        'security.md': 'security/security.md'
        'security_providers.md': 'security/security_providers.md'
        'tls_configuration_history.md': 'security/tls_configuration_history.md'
        # Redirect all changelog pages to changelog/*
        'changelog.md': 'changelogs/changelog.md'

from fastapi import FastAPI, Security
from fastapi.security.http import HTTPAuthorizationCredentials, HTTPBase
from fastapi.testclient import TestClient

app = FastAPI()

security = HTTPBase(scheme="Other")


@app.get("/users/me")
def read_current_user(credentials: HTTPAuthorizationCredentials = Security(security)):
    return {"scheme": credentials.scheme, "credentials": credentials.credentials}


client = TestClient(app)

from typing import Optional

from fastapi import FastAPI, Security
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
from fastapi.testclient import TestClient

app = FastAPI()

security = HTTPBearer(auto_error=False)


@app.get("/users/me")
def read_current_user(
    credentials: Optional[HTTPAuthorizationCredentials] = Security(security),
):
    if credentials is None:

 * saml.default.groups=user
 * saml.default.roles=user
 * </pre>
 *
 * <h2>Security Settings (Production)</h2>
 * <p>For production environments, consider enabling these security features:</p>
 * <pre>
 * saml.security.authnrequest_signed=true
 * saml.security.want_messages_signed=true
 * saml.security.want_assertions_signed=true
 * </pre>
 *

接下来，为*路径操作*  `/users/me/items/` 声明作用域 `items`。

为此，要从 `fastapi` 中导入并使用 `Security` 。

`Security` 声明依赖项的方式和 `Depends` 一样，但 `Security` 还能接收作用域（字符串）列表类型的参数 `scopes`。

此处使用与 `Depends` 相同的方式，把依赖项函数 `get_current_active_user` 传递给 `Security`。

同时，还传递了作用域**列表**，本例中只传递了一个作用域：`items`（此处支持传递更多作用域）。

依赖项函数 `get_current_active_user` 还能声明子依赖项，不仅可以使用 `Depends`，也可以使用 `Security`。声明子依赖项函数（`get_current_user`）及更多作用域。

本例要求使用作用域 `me`（还可以使用更多作用域）。