openethereum/dapps/src/web.rs
2017-07-04 16:43:53 +02:00

246 lines
7.0 KiB
Rust

// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
//! Serving web-based content (proxying)
use std::sync::Arc;
use fetch::{self, Fetch};
use parity_reactor::Remote;
use base32;
use hyper::{self, server, net, Next, Encoder, Decoder};
use hyper::status::StatusCode;
use apps;
use endpoint::{Endpoint, Handler, EndpointPath};
use handlers::{
ContentFetcherHandler, ContentHandler, ContentValidator, ValidatorResponse,
StreamingHandler, extract_url,
};
use url::Url;
use {Embeddable, WebProxyTokens};
pub struct Web<F> {
embeddable_on: Embeddable,
web_proxy_tokens: Arc<WebProxyTokens>,
remote: Remote,
fetch: F,
}
impl<F: Fetch> Web<F> {
pub fn boxed(
embeddable_on: Embeddable,
web_proxy_tokens: Arc<WebProxyTokens>,
remote: Remote,
fetch: F,
) -> Box<Endpoint> {
Box::new(Web {
embeddable_on,
web_proxy_tokens,
remote,
fetch,
})
}
}
impl<F: Fetch> Endpoint for Web<F> {
fn to_async_handler(&self, path: EndpointPath, control: hyper::Control) -> Box<Handler> {
Box::new(WebHandler {
control: control,
state: State::Initial,
path: path,
remote: self.remote.clone(),
fetch: self.fetch.clone(),
web_proxy_tokens: self.web_proxy_tokens.clone(),
embeddable_on: self.embeddable_on.clone(),
})
}
}
struct WebInstaller {
embeddable_on: Embeddable,
referer: String,
}
impl ContentValidator for WebInstaller {
type Error = String;
fn validate_and_install(&self, response: fetch::Response) -> Result<ValidatorResponse, String> {
let status = StatusCode::from_u16(response.status().to_u16());
let is_html = response.is_html();
let mime = response.content_type().unwrap_or(mime!(Text/Html));
let mut handler = StreamingHandler::new(
response,
status,
mime,
self.embeddable_on.clone(),
);
if is_html {
handler.set_initial_content(&format!(
r#"<script src="/{}/inject.js"></script><script>history.replaceState({{}}, "", "/?{}{}/{}")</script>"#,
apps::UTILS_PATH,
apps::URL_REFERER,
apps::WEB_PATH,
&self.referer,
));
}
Ok(ValidatorResponse::Streaming(handler))
}
}
enum State<F: Fetch> {
Initial,
Error(ContentHandler),
Fetching(ContentFetcherHandler<WebInstaller, F>),
}
struct WebHandler<F: Fetch> {
control: hyper::Control,
state: State<F>,
path: EndpointPath,
remote: Remote,
fetch: F,
web_proxy_tokens: Arc<WebProxyTokens>,
embeddable_on: Embeddable,
}
impl<F: Fetch> WebHandler<F> {
fn extract_target_url(&self, url: Option<Url>) -> Result<String, State<F>> {
let token_and_url = self.path.app_params.get(0)
.map(|encoded| encoded.replace('.', ""))
.and_then(|encoded| base32::decode(base32::Alphabet::Crockford, &encoded.to_uppercase()))
.and_then(|data| String::from_utf8(data).ok())
.ok_or_else(|| State::Error(ContentHandler::error(
StatusCode::BadRequest,
"Invalid parameter",
"Couldn't parse given parameter:",
self.path.app_params.get(0).map(String::as_str),
self.embeddable_on.clone()
)))?;
let mut token_it = token_and_url.split('+');
let token = token_it.next();
let target_url = token_it.next();
// Check if token supplied in URL is correct.
let domain = match token.and_then(|token| self.web_proxy_tokens.domain(token)) {
Some(domain) => domain,
_ => {
return Err(State::Error(ContentHandler::error(
StatusCode::BadRequest, "Invalid Access Token", "Invalid or old web proxy access token supplied.", Some("Try refreshing the page."), self.embeddable_on.clone()
)));
}
};
// Validate protocol
let mut target_url = match target_url {
Some(url) if url.starts_with("http://") || url.starts_with("https://") => url.to_owned(),
_ => {
return Err(State::Error(ContentHandler::error(
StatusCode::BadRequest, "Invalid Protocol", "Invalid protocol used.", None, self.embeddable_on.clone()
)));
}
};
if !target_url.starts_with(&*domain) {
return Err(State::Error(ContentHandler::error(
StatusCode::BadRequest, "Invalid Domain", "Dapp attempted to access invalid domain.", Some(&target_url), self.embeddable_on.clone(),
)));
}
if !target_url.ends_with("/") {
target_url = format!("{}/", target_url);
}
// TODO [ToDr] Should just use `path.app_params`
let (path, query) = match (&url, self.path.using_dapps_domains) {
(&Some(ref url), true) => (&url.path[..], &url.query),
(&Some(ref url), false) => (&url.path[2..], &url.query),
_ => {
return Err(State::Error(ContentHandler::error(
StatusCode::BadRequest, "Invalid URL", "Couldn't parse URL", None, self.embeddable_on.clone()
)));
}
};
let query = match *query {
Some(ref query) => format!("?{}", query),
None => "".into(),
};
Ok(format!("{}{}{}", target_url, path.join("/"), query))
}
}
impl<F: Fetch> server::Handler<net::HttpStream> for WebHandler<F> {
fn on_request(&mut self, request: server::Request<net::HttpStream>) -> Next {
let url = extract_url(&request);
// First extract the URL (reject invalid URLs)
let target_url = match self.extract_target_url(url) {
Ok(url) => url,
Err(error) => {
self.state = error;
return Next::write();
}
};
let mut handler = ContentFetcherHandler::new(
target_url,
self.path.clone(),
self.control.clone(),
WebInstaller {
embeddable_on: self.embeddable_on.clone(),
referer: self.path.app_params.get(0)
.expect("`target_url` is valid; app_params is not empty;qed")
.to_owned(),
},
self.embeddable_on.clone(),
self.remote.clone(),
self.fetch.clone(),
);
let res = handler.on_request(request);
self.state = State::Fetching(handler);
res
}
fn on_request_readable(&mut self, decoder: &mut Decoder<net::HttpStream>) -> Next {
match self.state {
State::Initial => Next::end(),
State::Error(ref mut handler) => handler.on_request_readable(decoder),
State::Fetching(ref mut handler) => handler.on_request_readable(decoder),
}
}
fn on_response(&mut self, res: &mut server::Response) -> Next {
match self.state {
State::Initial => Next::end(),
State::Error(ref mut handler) => handler.on_response(res),
State::Fetching(ref mut handler) => handler.on_response(res),
}
}
fn on_response_writable(&mut self, encoder: &mut Encoder<net::HttpStream>) -> Next {
match self.state {
State::Initial => Next::end(),
State::Error(ref mut handler) => handler.on_response_writable(encoder),
State::Fetching(ref mut handler) => handler.on_response_writable(encoder),
}
}
}