1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
#![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg))]
#![doc = include_str!("../README.md")]
// @@ begin lint list maintained by maint/add_warning @@
#![cfg_attr(not(ci_arti_stable), allow(renamed_and_removed_lints))]
#![cfg_attr(not(ci_arti_nightly), allow(unknown_lints))]
#![warn(missing_docs)]
#![warn(noop_method_call)]
#![warn(unreachable_pub)]
#![warn(clippy::all)]
#![deny(clippy::await_holding_lock)]
#![deny(clippy::cargo_common_metadata)]
#![deny(clippy::cast_lossless)]
#![deny(clippy::checked_conversions)]
#![warn(clippy::cognitive_complexity)]
#![deny(clippy::debug_assert_with_mut_call)]
#![deny(clippy::exhaustive_enums)]
#![deny(clippy::exhaustive_structs)]
#![deny(clippy::expl_impl_clone_on_copy)]
#![deny(clippy::fallible_impl_from)]
#![deny(clippy::implicit_clone)]
#![deny(clippy::large_stack_arrays)]
#![warn(clippy::manual_ok_or)]
#![deny(clippy::missing_docs_in_private_items)]
#![warn(clippy::needless_borrow)]
#![warn(clippy::needless_pass_by_value)]
#![warn(clippy::option_option)]
#![deny(clippy::print_stderr)]
#![deny(clippy::print_stdout)]
#![warn(clippy::rc_buffer)]
#![deny(clippy::ref_option_ref)]
#![warn(clippy::semicolon_if_nothing_returned)]
#![warn(clippy::trait_duplication_in_bounds)]
#![deny(clippy::unnecessary_wraps)]
#![warn(clippy::unseparated_literal_suffix)]
#![deny(clippy::unwrap_used)]
#![allow(clippy::let_unit_value)] // This can reasonably be done for explicitness
#![allow(clippy::uninlined_format_args)]
#![allow(clippy::significant_drop_in_scrutinee)] // arti/-/merge_requests/588/#note_2812945
#![allow(clippy::result_large_err)] // temporary workaround for arti#587
#![allow(clippy::needless_raw_string_hashes)] // complained-about code is fine, often best
//! <!-- @@ end lint list maintained by maint/add_warning @@ -->

use std::future::Future;
use std::io::Error;
use std::pin::Pin;
use std::sync::Arc;
use std::task::{Context, Poll};

use arti_client::{DataStream, IntoTorAddr, TorClient};
use educe::Educe;
use hyper::client::connect::{Connected, Connection};
use hyper::http::uri::Scheme;
use hyper::http::Uri;
use hyper::service::Service;
use pin_project::pin_project;
use thiserror::Error;
use tls_api::TlsConnector as TlsConn; // This is different from tor_rtcompat::TlsConnector
use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
use tor_rtcompat::Runtime;

/// Error making or using http connection
///
/// This error ends up being passed to hyper and bundled up into a [`hyper::Error`]
#[derive(Error, Clone, Debug)]
#[non_exhaustive]
pub enum ConnectionError {
    /// Unsupported URI scheme
    #[error("unsupported URI scheme in {uri:?}")]
    UnsupportedUriScheme {
        /// URI
        uri: Uri,
    },

    /// Missing hostname
    #[error("Missing hostname in {uri:?}")]
    MissingHostname {
        /// URI
        uri: Uri,
    },

    /// Tor connection failed
    #[error("Tor connection failed")]
    Arti(#[from] arti_client::Error),

    /// TLS connection failed
    #[error("TLS connection failed")]
    TLS(#[source] Arc<anyhow::Error>),
}

/// We implement this for form's sake
impl tor_error::HasKind for ConnectionError {
    #[rustfmt::skip]
    fn kind(&self) -> tor_error::ErrorKind {
        use ConnectionError as CE;
        use tor_error::ErrorKind as EK;
        match self {
            CE::UnsupportedUriScheme{..} => EK::NotImplemented,
            CE::MissingHostname{..}      => EK::BadApiUsage,
            CE::Arti(e)                  => e.kind(),
            CE::TLS(_)                   => EK::RemoteProtocolViolation,
        }
    }
}

/// **Main entrypoint**: `hyper` connector to make HTTP\[S] connections via Tor, using Arti.
///
/// An `ArtiHttpConnector` combines an Arti Tor client, and a TLS implementation,
/// in a form that can be provided to hyper
/// (e.g. to [`hyper::client::Builder`]'s `build` method)
/// so that hyper can speak HTTP and HTTPS to origin servers via Tor.
///
/// TC is the TLS to used *across* Tor to connect to the origin server.
/// For example, it could be a [`tls_api_native_tls::TlsConnector`].
/// This is a different Rust type to the TLS used *by* Tor to connect to relays etc.
/// It might even be a different underlying TLS implementation
/// (although that is usually not a particularly good idea).
#[derive(Educe)]
#[educe(Clone)] // #[derive(Debug)] infers an unwanted bound TC: Clone
pub struct ArtiHttpConnector<R: Runtime, TC: TlsConn> {
    /// The client
    client: TorClient<R>,

    /// TLS for using across Tor.
    tls_conn: Arc<TC>,
}

// #[derive(Clone)] infers a TC: Clone bound

impl<R: Runtime, TC: TlsConn> ArtiHttpConnector<R, TC> {
    /// Make a new `ArtiHttpConnector` using an Arti `TorClient` object.
    pub fn new(client: TorClient<R>, tls_conn: TC) -> Self {
        let tls_conn = tls_conn.into();
        Self { client, tls_conn }
    }
}

/// Wrapper type that makes an Arti `DataStream` implement necessary traits to be used as
/// a `hyper` connection object (mainly `Connection`).
///
/// This might represent a bare HTTP connection across Tor,
/// or it might represent an HTTPS connection through Tor to an origin server,
/// `TC::TlsStream` as the TLS layer.
///
/// An `ArtiHttpConnection` is constructed by hyper's use of the [`ArtiHttpConnector`]
/// implementation of [`hyper::service::Service`],
/// and then used by hyper as the transport for hyper's HTTP implementation.
#[pin_project]
pub struct ArtiHttpConnection<TC: TlsConn> {
    /// The stream
    #[pin]
    inner: MaybeHttpsStream<TC>,
}

/// The actual actual stream; might be TLS, might not
#[pin_project(project = MaybeHttpsStreamProj)]
enum MaybeHttpsStream<TC: TlsConn> {
    /// http
    Http(Pin<Box<DataStream>>), // Tc:TlsStream is generally boxed; box this one too

    /// https
    Https(#[pin] TC::TlsStream),
}

impl<TC: TlsConn> Connection for ArtiHttpConnection<TC> {
    fn connected(&self) -> Connected {
        Connected::new()
    }
}

// These trait implementations just defer to the inner `DataStream`; the wrapper type is just
// there to implement the `Connection` trait.
impl<TC: TlsConn> AsyncRead for ArtiHttpConnection<TC> {
    fn poll_read(
        self: Pin<&mut Self>,
        cx: &mut Context<'_>,
        buf: &mut ReadBuf<'_>,
    ) -> Poll<Result<(), std::io::Error>> {
        match self.project().inner.project() {
            MaybeHttpsStreamProj::Http(ds) => ds.as_mut().poll_read(cx, buf),
            MaybeHttpsStreamProj::Https(t) => t.poll_read(cx, buf),
        }
    }
}

impl<TC: TlsConn> AsyncWrite for ArtiHttpConnection<TC> {
    fn poll_write(
        self: Pin<&mut Self>,
        cx: &mut Context<'_>,
        buf: &[u8],
    ) -> Poll<Result<usize, Error>> {
        match self.project().inner.project() {
            MaybeHttpsStreamProj::Http(ds) => ds.as_mut().poll_write(cx, buf),
            MaybeHttpsStreamProj::Https(t) => t.poll_write(cx, buf),
        }
    }

    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
        match self.project().inner.project() {
            MaybeHttpsStreamProj::Http(ds) => ds.as_mut().poll_flush(cx),
            MaybeHttpsStreamProj::Https(t) => t.poll_flush(cx),
        }
    }

    fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
        match self.project().inner.project() {
            MaybeHttpsStreamProj::Http(ds) => ds.as_mut().poll_shutdown(cx),
            MaybeHttpsStreamProj::Https(t) => t.poll_shutdown(cx),
        }
    }
}

#[derive(Debug, Clone, Copy, Eq, PartialEq)]
/// Are we doing TLS?
enum UseTls {
    /// No
    Bare,

    /// Yes
    Tls,
}

/// Convert uri to http\[s\] host and port, and whether to do tls
fn uri_to_host_port_tls(uri: Uri) -> Result<(String, u16, UseTls), ConnectionError> {
    let use_tls = {
        // Scheme doesn't derive PartialEq so can't be matched on
        let scheme = uri.scheme();
        if scheme == Some(&Scheme::HTTP) {
            UseTls::Bare
        } else if scheme == Some(&Scheme::HTTPS) {
            UseTls::Tls
        } else {
            return Err(ConnectionError::UnsupportedUriScheme { uri });
        }
    };
    let host = match uri.host() {
        Some(h) => h,
        _ => return Err(ConnectionError::MissingHostname { uri }),
    };
    let port = uri.port().map(|x| x.as_u16()).unwrap_or(match use_tls {
        UseTls::Tls => 443,
        UseTls::Bare => 80,
    });

    Ok((host.to_owned(), port, use_tls))
}

impl<R: Runtime, TC: TlsConn> Service<Uri> for ArtiHttpConnector<R, TC> {
    type Response = ArtiHttpConnection<TC>;
    type Error = ConnectionError;
    #[allow(clippy::type_complexity)]
    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;

    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        Poll::Ready(Ok(()))
    }

    fn call(&mut self, req: Uri) -> Self::Future {
        // `TorClient` objects can be cloned cheaply (the cloned objects refer to the same
        // underlying handles required to make Tor connections internally).
        // We use this to avoid the returned future having to borrow `self`.
        let client = self.client.clone();
        let tls_conn = self.tls_conn.clone();
        Box::pin(async move {
            // Extract the host and port to connect to from the URI.
            let (host, port, use_tls) = uri_to_host_port_tls(req)?;
            // Initiate a new Tor connection, producing a `DataStream` if successful.
            let addr = (&host as &str, port)
                .into_tor_addr()
                .map_err(arti_client::Error::from)?;
            let ds = client.connect(addr).await?;

            let inner = match use_tls {
                UseTls::Tls => {
                    let conn = tls_conn
                        .connect_impl_tls_stream(&host, ds)
                        .await
                        .map_err(|e| ConnectionError::TLS(e.into()))?;
                    MaybeHttpsStream::Https(conn)
                }
                UseTls::Bare => MaybeHttpsStream::Http(Box::new(ds).into()),
            };

            Ok(ArtiHttpConnection { inner })
        })
    }
}

#[cfg(test)]
mod test {
    // @@ begin test lint list maintained by maint/add_warning @@
    #![allow(clippy::bool_assert_comparison)]
    #![allow(clippy::clone_on_copy)]
    #![allow(clippy::dbg_macro)]
    #![allow(clippy::print_stderr)]
    #![allow(clippy::print_stdout)]
    #![allow(clippy::single_char_pattern)]
    #![allow(clippy::unwrap_used)]
    #![allow(clippy::unchecked_duration_subtraction)]
    #![allow(clippy::useless_vec)]
    #![allow(clippy::needless_pass_by_value)]
    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
    use super::*;

    fn make_uri(url: &str) -> Uri {
        url.parse::<Uri>().expect("Unable to parse uri")
    }

    #[test]
    fn check_supported_uri_schemes() {
        // Unsupported URI schemes should return an error
        let unsupported = [
            "wss://torproject.org",
            "file://torproject.org",
            "ftp://torproject.org",
            "vnc://torproject.org",
            "/no/scheme",
        ];
        for url in unsupported {
            assert!(uri_to_host_port_tls(make_uri(url)).is_err());
        }

        // Supported URI schemes should return a result with correct TLS setting
        let supported = [
            ("https://torproject.org", UseTls::Tls),
            ("http://torproject.org", UseTls::Bare),
        ];
        for (url, tls) in supported {
            let (_ret_host, _ret_port, ret_tls) =
                uri_to_host_port_tls(make_uri(url)).expect("function should return Result");

            assert_eq!(ret_tls, tls);
        }
    }

    #[test]
    fn get_correct_port_and_tls_from_uri() {
        // (1) Custom ports should be used when explicitly specified, otherwise correct defaults should be used
        // (2) TLS setting should be dependent on URI scheme, not port
        let urls = [
            ("https://torproject.org:999", 999, UseTls::Tls),
            ("https://torproject.org:80", 80, UseTls::Tls),
            ("https://torproject.org", 443, UseTls::Tls),
            ("http://torproject.org:999", 999, UseTls::Bare),
            ("http://torproject.org:443", 443, UseTls::Bare),
            ("http://torproject.org", 80, UseTls::Bare),
        ];

        for (url, port, tls) in urls {
            let (_ret_host, ret_port, ret_tls) =
                uri_to_host_port_tls(make_uri(url)).expect("function should return Result");

            assert_eq!(ret_port, port);
            assert_eq!(ret_tls, tls);
        }
    }

    #[test]
    fn get_correct_host_from_uri() {
        let urls = [
            ("https://torproject.org", "torproject.org"),
            ("http://torproject.org", "torproject.org"),
        ];

        for (url, host) in urls {
            let (ret_host, _ret_port, _ret_tls) =
                uri_to_host_port_tls(make_uri(url)).expect("function should return Result");

            assert_eq!(ret_host, host);
        }
    }
}