Files
yup-oauth2/src/device.rs
2020-11-12 20:31:19 -05:00

205 lines
8.2 KiB
Rust

use crate::authenticator_delegate::{
DefaultDeviceFlowDelegate, DeviceAuthResponse, DeviceFlowDelegate,
};
use crate::error::{AuthError, Error};
use crate::types::{ApplicationSecret, TokenInfo};
use std::borrow::Cow;
use std::time::Duration;
use hyper::header;
use url::form_urlencoded;
pub const GOOGLE_DEVICE_CODE_URL: &str = "https://accounts.google.com/o/oauth2/device/code";
// https://developers.google.com/identity/protocols/OAuth2ForDevices#step-4:-poll-googles-authorization-server
pub const GOOGLE_GRANT_TYPE: &str = "http://oauth.net/grant_type/device/1.0";
/// Implements the [Oauth2 Device Flow](https://developers.google.com/youtube/v3/guides/authentication#devices)
/// It operates in two steps:
/// * obtain a code to show to the user
/// * (repeatedly) poll for the user to authenticate your application
pub struct DeviceFlow {
pub(crate) app_secret: ApplicationSecret,
pub(crate) device_code_url: Cow<'static, str>,
pub(crate) flow_delegate: Box<dyn DeviceFlowDelegate>,
pub(crate) grant_type: Cow<'static, str>,
}
impl DeviceFlow {
/// Create a new DeviceFlow. The default FlowDelegate will be used and the
/// default wait time is 120 seconds.
pub(crate) fn new(app_secret: ApplicationSecret) -> Self {
DeviceFlow {
app_secret,
device_code_url: GOOGLE_DEVICE_CODE_URL.into(),
flow_delegate: Box::new(DefaultDeviceFlowDelegate),
grant_type: GOOGLE_GRANT_TYPE.into(),
}
}
pub(crate) async fn token<C, T>(
&self,
hyper_client: &hyper::Client<C>,
scopes: &[T],
) -> Result<TokenInfo, Error>
where
T: AsRef<str>,
C: hyper::client::connect::Connect + Clone + Send + Sync + 'static,
{
let device_auth_resp = Self::request_code(
&self.app_secret,
hyper_client,
&self.device_code_url,
scopes,
)
.await?;
log::debug!("Presenting code to user");
self.flow_delegate
.present_user_code(&device_auth_resp)
.await;
self.wait_for_device_token(
hyper_client,
&self.app_secret,
&device_auth_resp,
&self.grant_type,
)
.await
}
async fn wait_for_device_token<C>(
&self,
hyper_client: &hyper::Client<C>,
app_secret: &ApplicationSecret,
device_auth_resp: &DeviceAuthResponse,
grant_type: &str,
) -> Result<TokenInfo, Error>
where
C: hyper::client::connect::Connect + Clone + Send + Sync + 'static,
{
let mut interval = device_auth_resp.interval;
log::debug!("Polling every {:?} for device token", interval);
loop {
tokio::time::sleep(interval).await;
interval = match Self::poll_token(
&app_secret,
hyper_client,
&device_auth_resp.device_code,
grant_type,
)
.await
{
Ok(token) => return Ok(token),
Err(Error::AuthError(AuthError { error, .. }))
if error.as_str() == "authorization_pending" =>
{
log::debug!("still waiting on authorization from the server");
interval
}
Err(Error::AuthError(AuthError { error, .. })) if error.as_str() == "slow_down" => {
let interval = interval + Duration::from_secs(5);
log::debug!(
"server requested slow_down. Increasing polling interval to {:?}",
interval
);
interval
}
Err(err) => return Err(err),
}
}
}
/// The first step involves asking the server for a code that the user
/// can type into a field at a specified URL. It is called only once, assuming
/// there was no connection error. Otherwise, it may be called again until
/// you receive an `Ok` result.
/// # Arguments
/// * `client_id` & `client_secret` - as obtained when [registering your application](https://developers.google.com/youtube/registering_an_application)
/// * `scopes` - an iterator yielding String-like objects which are URLs defining what your
/// application is able to do. It is considered good behaviour to authenticate
/// only once, with all scopes you will ever require.
/// However, you can also manage multiple tokens for different scopes, if your
/// application is providing distinct read-only and write modes.
/// # Panics
/// * If called after a successful result was returned at least once.
/// # Examples
/// See test-cases in source code for a more complete example.
async fn request_code<C, T>(
application_secret: &ApplicationSecret,
client: &hyper::Client<C>,
device_code_url: &str,
scopes: &[T],
) -> Result<DeviceAuthResponse, Error>
where
T: AsRef<str>,
C: hyper::client::connect::Connect + Clone + Send + Sync + 'static,
{
let req = form_urlencoded::Serializer::new(String::new())
.extend_pairs(&[
("client_id", application_secret.client_id.as_str()),
("scope", crate::helper::join(scopes, " ").as_str()),
])
.finish();
// note: works around bug in rustlang
// https://github.com/rust-lang/rust/issues/22252
let req = hyper::Request::post(device_code_url)
.header(header::CONTENT_TYPE, "application/x-www-form-urlencoded")
.body(hyper::Body::from(req))
.unwrap();
log::debug!("requesting code from server: {:?}", req);
let (head, body) = client.request(req).await?.into_parts();
let body = hyper::body::to_bytes(body).await?;
log::debug!("received response; head: {:?}, body: {:?}", head, body);
DeviceAuthResponse::from_json(&body)
}
/// If the first call is successful, this method may be called.
/// As long as we are waiting for authentication, it will return `Ok(None)`.
/// You should call it within the interval given the previously returned
/// `DeviceAuthResponse.interval` field.
///
/// The operation was successful once you receive an Ok(Some(Token)) for the first time.
/// Subsequent calls will return the previous result, which may also be an error state.
///
/// Do not call after `PollError::Expired|PollError::AccessDenied` was among the
/// `Err(PollError)` variants as the flow will not do anything anymore.
/// Thus in any unsuccessful case which is not `PollError::HttpError`, you will have to start
/// over the entire flow, which requires a new instance of this type.
///
/// > ⚠️ **Warning**: We assume the caller doesn't call faster than `interval` and are not
/// > protected against this kind of mis-use.
///
/// # Examples
/// See test-cases in source code for a more complete example.
async fn poll_token<'a, C>(
application_secret: &ApplicationSecret,
client: &hyper::Client<C>,
device_code: &str,
grant_type: &str,
) -> Result<TokenInfo, Error>
where
C: hyper::client::connect::Connect + Clone + Send + Sync + 'static,
{
// We should be ready for a new request
let req = form_urlencoded::Serializer::new(String::new())
.extend_pairs(&[
("client_id", application_secret.client_id.as_str()),
("client_secret", application_secret.client_secret.as_str()),
("code", device_code),
("grant_type", grant_type),
])
.finish();
let request = hyper::Request::post(&application_secret.token_uri)
.header(header::CONTENT_TYPE, "application/x-www-form-urlencoded")
.body(hyper::Body::from(req))
.unwrap(); // TODO: Error checking
log::debug!("polling for token: {:?}", request);
let (head, body) = client.request(request).await?.into_parts();
let body = hyper::body::to_bytes(body).await?;
log::debug!("received response; head: {:?} body: {:?}", head, body);
TokenInfo::from_json(&body)
}
}