//! Implement the socks handshakes.

#[cfg(any(feature = "proxy-handshake", feature = "client-handshake"))]

#[macro_use]

pub(crate) mod framework;

#[cfg(feature = "client-handshake")]

pub(crate) mod client;

#[cfg(feature = "proxy-handshake")]

pub(crate) mod proxy;

use crate::msg::SocksAddr;

use std::net::IpAddr;

use tor_bytes::Result as BytesResult;

use tor_bytes::{EncodeResult, Error as BytesError, Readable, Reader, Writeable, Writer};

/// Constant for Username/Password-style authentication.

/// (See RFC 1929)

const USERNAME_PASSWORD: u8 = 0x02;

/// Constant for "no authentication".

const NO_AUTHENTICATION: u8 = 0x00;

/// An action to take in response to a SOCKS handshake message.

#[derive(Clone, Debug)]

#[non_exhaustive]

pub struct Action {

    /// If nonzero, this many bytes should be drained from the

    /// client's inputs.

    pub drain: usize,

    /// If nonempty, this reply should be sent to the other party.

    pub reply: Vec<u8>,

    /// If true, then this handshake is over, either successfully or not.

    pub finished: bool,

}

impl Readable for SocksAddr {

            1 => {

            }

            3 => {

            }

            4 => {

            }

        }

}

impl Writeable for SocksAddr {

            }

            }

            }

        }

}

#[cfg(all(feature = "client-handshake", feature = "proxy-handshake"))]

#[cfg(test)]

mod test_roundtrip {

    // @@ begin test lint list

    #![allow(clippy::bool_assert_comparison)]

    #![allow(clippy::clone_on_copy)]

    #![allow(clippy::dbg_macro)]

    #![allow(clippy::mixed_attributes_style)]

    #![allow(clippy::print_stderr)]

    #![allow(clippy::print_stdout)]

    #![allow(clippy::single_char_pattern)]

    #![allow(clippy::unwrap_used)]

    #![allow(clippy::unchecked_time_subtraction)]

    #![allow(clippy::useless_vec)]

    #![allow(clippy::needless_pass_by_value)]

    #![allow(clippy::string_slice)] // See arti#2571

    //! <!-- @@ end test lint list

    use crate::*;

    use std::collections::VecDeque;

    /// Given a socks request, run a complete (successful round) trip, reply with the

    /// the given status code, and return both sides' results.

    ///

    /// Use the (deprecated) `Handshake::handshake` and `Action` API

    fn run_handshake_old_api(

        request: SocksRequest,

        status: SocksStatus,

    ) -> (SocksRequest, SocksReply) {

        let mut client_hs = SocksClientHandshake::new(request);

        let mut proxy_hs = SocksProxyHandshake::new();

        let mut received_request = None;

        let mut last_proxy_msg = vec![];

        // Prevent infinite loop in case of bugs.

        for _ in 0..100 {

            // Make sure that the client says "truncated" for all prefixes of the proxy's message.

            for truncate in 0..last_proxy_msg.len() {

                let r = client_hs.handshake_for_tests(&last_proxy_msg[..truncate]);

                assert!(r.is_err());

            }

            // Get the client's actual message.

            let client_action = client_hs

                .handshake_for_tests(&last_proxy_msg)

                .unwrap()

                .unwrap();

            assert_eq!(client_action.drain, last_proxy_msg.len());

            if client_action.finished {

                let received_reply = client_hs.into_reply();

                return (received_request.unwrap(), received_reply.unwrap());

            }

            let client_msg = client_action.reply;

            // Make sure that the proxy says "truncated" for all prefixes of the client's message.

            for truncate in 0..client_msg.len() {

                let r = proxy_hs.handshake_for_tests(&client_msg[..truncate]);

                assert!(r.is_err());

            }

            // Get the proxy's actual reply (if any).

            let proxy_action = proxy_hs.handshake_for_tests(&client_msg).unwrap().unwrap();

            assert_eq!(proxy_action.drain, client_msg.len());

            last_proxy_msg = if proxy_action.finished {

                // The proxy is done: have it reply with a status code.

                received_request = proxy_hs.clone().into_request();

                received_request

                    .as_ref()

                    .unwrap()

                    .reply(status, None)

                    .unwrap()

            } else {

                proxy_action.reply

            };

        }

        panic!("Handshake ran for too many steps")

    }

    /// Given a socks request, run a complete (successful round) trip, reply with the

    /// the given status code, and return both sides' results.

    ///

    /// Use the (new) `Handshake::step` API

    fn run_handshake_new_api<P: ReadPrecision, const MAX_RECV: usize>(

        request: SocksRequest,

        status: SocksStatus,

    ) -> (SocksRequest, SocksReply) {

        struct State<P: ReadPrecision, H: Handshake> {

            hs: H,

            buf: Buffer<P>,

            fin: Option<H::Output>,

        }

        struct DidSomething;

        let mut client = State::<P, _>::new(SocksClientHandshake::new(request));

        let mut server = State::<P, _>::new(SocksProxyHandshake::new());

        let mut c2s = VecDeque::new();

        let mut s2c = VecDeque::new();

        let mut status = Some(status);

        impl<P: ReadPrecision, H: Handshake> State<P, H> {

            fn new(hs: H) -> Self {

                State {

                    hs,

                    buf: Default::default(),

                    fin: None,

                }

            }

            fn progress_1(

                &mut self,

                max_recv: usize,

                rx: &mut VecDeque<u8>,

                tx: &mut VecDeque<u8>,

            ) -> Option<DidSomething> {

                use NextStep as NS;

                if self.fin.is_some() {

                    return None;

                }

                match self.hs.step(&mut self.buf).unwrap() {

                    NS::Recv(mut recv) => {

                        let n = [recv.buf().len(), rx.len(), max_recv]

                            .into_iter()

                            .min()

                            .unwrap();

                        for p in &mut recv.buf()[0..n] {

                            *p = rx.pop_front().unwrap();

                        }

                        recv.note_received(n).unwrap_or_else(|e| match e {

                            // This is actually expected; our test case produces 0-byte reads

                            // sometimes.

                            Error::UnexpectedEof => {}

                            other => panic!("{:?}", other),

                        });

                        if n != 0 { Some(DidSomething) } else { None }

                    }

                    NS::Send(send) => {

                        for c in send {

                            tx.push_back(c);

                        }

                        Some(DidSomething)

                    }

                    NS::Finished(fin) => {

                        self.fin = Some(fin.into_output_forbid_pipelining().unwrap());

                        Some(DidSomething)

                    }

                }

            }

        }

        loop {

            let ds = [

                client.progress_1(MAX_RECV, &mut s2c, &mut c2s),

                server.progress_1(MAX_RECV, &mut c2s, &mut s2c),

            ]

            .into_iter()

            .flatten()

            .next();

            if let Some(DidSomething) = ds {

                continue;

            }

            let Some(status) = status.take() else { break };

            let reply = server.fin.as_ref().unwrap().reply(status, None).unwrap();

            for c in reply {

                s2c.push_back(c);

            }

        }

        (server.fin.unwrap(), client.fin.unwrap())

    }

    // Invoke run_handshake and assert that the output matches the input.

    fn test_handshake(request: &SocksRequest, status: SocksStatus) {

        for run_handshake in [

            run_handshake_old_api,

            run_handshake_new_api::<(), 1>,

            run_handshake_new_api::<(), 100>,

            run_handshake_new_api::<PreciseReads, 1>,

            run_handshake_new_api::<PreciseReads, 100>,

        ] {

            let (request_out, status_out) = run_handshake(request.clone(), status);

            assert_eq!(&request_out, request);

            assert_eq!(status_out.status(), status);

        }

    }

    #[test]

    fn socks4() {

        test_handshake(

            &SocksRequest::new(

                SocksVersion::V4,

                SocksCmd::CONNECT,

                SocksAddr::Hostname("www.torproject.org".to_string().try_into().unwrap()),

                443,

                SocksAuth::NoAuth,

            )

            .unwrap(),

            SocksStatus::SUCCEEDED,

        );

        test_handshake(

            &SocksRequest::new(

                SocksVersion::V4,

                SocksCmd::CONNECT,

                SocksAddr::Ip("192.0.2.33".parse().unwrap()),

                22,

                SocksAuth::Socks4(b"swordfish".to_vec()),

            )

            .unwrap(),

            SocksStatus::GENERAL_FAILURE,

        );

    }

    #[test]

    fn socks5() {

        test_handshake(

            &SocksRequest::new(

                SocksVersion::V5,

                SocksCmd::CONNECT,

                SocksAddr::Hostname("www.torproject.org".to_string().try_into().unwrap()),

                443,

                SocksAuth::NoAuth,

            )

            .unwrap(),

            SocksStatus::SUCCEEDED,

        );

        test_handshake(

            &SocksRequest::new(

                SocksVersion::V5,

                SocksCmd::CONNECT,

                SocksAddr::Ip("2001:db8::32".parse().unwrap()),

                443,

                SocksAuth::Username(b"belbo".to_vec(), b"non".to_vec()),

            )

            .unwrap(),

            SocksStatus::GENERAL_FAILURE,

        );

    }

}