Initial support digest auth scheme

Cargo.toml

@@ -23,6 +23,9 @@ prctl = "1.0"
 smoltcp = { version = "0.9.1", git = "https://github.com/smoltcp-rs/smoltcp", features = ["std", "phy-tuntap_interface"] }
 thiserror = "1.0"
 url = "2.3"
+digest_auth = "0.3.1"
+httparse = "1.8.0"
+unicase = "2.6.0"
 
 [target.'cfg(target_os="android")'.dependencies]
 android_logger = "0.13"

src/error.rs

@@ -48,6 +48,12 @@ pub enum Error {
 
     #[error("std::num::ParseIntError {0:?}")]
     IntParseError(#[from] std::num::ParseIntError),
+
+    #[error("httparse::Error {0}")]
+    HttpError(#[from] httparse::Error),
+
+    #[error("digest_auth::Error {0}")]
+    DigestAuthError(#[from] digest_auth::Error),
 }
 
 impl From<&str> for Error {

src/http.rs

@@ -1,24 +1,41 @@
 use crate::error::Error;
 use crate::tun2proxy::{
-    Connection, ConnectionManager, Direction, IncomingDataEvent, IncomingDirection,
+    Connection, ConnectionManager, Destination, Direction, IncomingDataEvent, IncomingDirection,
     OutgoingDataEvent, OutgoingDirection, TcpProxy,
 };
 use crate::Credentials;
 use base64::Engine;
+use httparse::Response;
 use smoltcp::wire::IpProtocol;
-use std::collections::VecDeque;
+use std::cell::RefCell;
+use std::collections::hash_map::RandomState;
+use std::collections::{HashMap, VecDeque};
+use std::iter::FromIterator;
 use std::net::SocketAddr;
 use std::rc::Rc;
+use std::str;
+use unicase::UniCase;
+
+#[derive(Eq, PartialEq, Debug)]
+#[allow(dead_code)]
+enum AuthenticationScheme {
+    None,
+    Basic,
+    Digest,
+}
 
 #[derive(Eq, PartialEq, Debug)]
 #[allow(dead_code)]
 enum HttpState {
     SendRequest,
-    ExpectStatusCode,
+    ExpectResponseHeaders,
     ExpectResponse,
+    Reset,
     Established,
 }
 
+pub(crate) type DigestState = digest_auth::WwwAuthenticateHeader;
+
 pub struct HttpConnection {
     state: HttpState,
     client_inbuf: VecDeque<u8>,
@@ -27,82 +44,264 @@ pub struct HttpConnection {
     server_outbuf: VecDeque<u8>,
     data_buf: VecDeque<u8>,
     crlf_state: u8,
+    counter: usize,
+    skip: usize,
+    digest_state: Rc<RefCell<Option<DigestState>>>,
+    before: bool,
+    credentials: Option<Credentials>,
+    destination: Destination,
 }
 
-impl HttpConnection {
-    fn new(connection: &Connection, manager: Rc<dyn ConnectionManager>) -> Self {
-        let mut server_outbuf: VecDeque<u8> = VecDeque::new();
-        {
-            let credentials = manager.get_credentials();
-            server_outbuf.extend(b"CONNECT ".iter());
-            server_outbuf.extend(connection.dst.to_string().as_bytes());
-            server_outbuf.extend(b" HTTP/1.1\r\nHost: ".iter());
-            server_outbuf.extend(connection.dst.to_string().as_bytes());
-            server_outbuf.extend(b"\r\n".iter());
-            if let Some(credentials) = credentials {
-                server_outbuf.extend(b"Proxy-Authorization: Basic ");
-                let mut auth_plain = credentials.username.clone();
-                auth_plain.extend(b":".iter());
-                auth_plain.extend(&credentials.password);
-                let auth_b64 = base64::engine::general_purpose::STANDARD.encode(auth_plain);
-                server_outbuf.extend(auth_b64.as_bytes().iter());
-                server_outbuf.extend(b"\r\n".iter());
-            }
-            server_outbuf.extend(b"\r\n".iter());
-        }
+static PROXY_AUTHENTICATE: &str = "Proxy-Authenticate";
+static PROXY_AUTHORIZATION: &str = "Proxy-Authorization";
+static CONNECTION: &str = "Connection";
+static TRANSFER_ENCODING: &str = "Transfer-Encoding";
+static CONTENT_LENGTH: &str = "Content-Length";
 
-        Self {
-            state: HttpState::ExpectStatusCode,
+impl HttpConnection {
+    fn new(
+        connection: &Connection,
+        manager: Rc<dyn ConnectionManager>,
+        digest_state: Rc<RefCell<Option<DigestState>>>,
+    ) -> Result<Self, Error> {
+        let mut res = Self {
+            state: HttpState::ExpectResponseHeaders,
             client_inbuf: Default::default(),
             server_inbuf: Default::default(),
             client_outbuf: Default::default(),
-            server_outbuf,
+            server_outbuf: Default::default(),
             data_buf: Default::default(),
-            crlf_state: Default::default(),
+            skip: 0,
+            counter: 0,
+            crlf_state: 0,
+            digest_state,
+            before: false,
+            credentials: manager.get_credentials().clone(),
+            destination: connection.dst.clone(),
+        };
+
+        res.send_tunnel_request()?;
+        Ok(res)
+    }
+
+    fn send_tunnel_request(&mut self) -> Result<(), Error> {
+        self.server_outbuf.extend(b"CONNECT ");
+        self.server_outbuf
+            .extend(self.destination.to_string().as_bytes());
+        self.server_outbuf.extend(b" HTTP/1.1\r\nHost: ");
+        self.server_outbuf
+            .extend(self.destination.to_string().as_bytes());
+        self.server_outbuf.extend(b"\r\n");
+
+        self.send_auth_data(if self.digest_state.borrow().is_none() {
+            AuthenticationScheme::Basic
+        } else {
+            AuthenticationScheme::Digest
+        })?;
+
+        self.server_outbuf.extend(b"\r\n");
+        Ok(())
+    }
+
+    fn send_auth_data(&mut self, scheme: AuthenticationScheme) -> Result<(), Error> {
+        let Some(credentials) = &self.credentials else {
+            return Ok(());
+        };
+
+        match scheme {
+            AuthenticationScheme::Digest => {
+                let uri = format!("{}:{}", self.destination.host, self.destination.port);
+
+                let context = digest_auth::AuthContext::new_with_method(
+                    &credentials.username,
+                    &credentials.password,
+                    &uri,
+                    Option::<&'_ [u8]>::None,
+                    digest_auth::HttpMethod::CONNECT,
+                );
+
+                let mut state = self.digest_state.borrow_mut();
+                let response = state.as_mut().unwrap().respond(&context)?;
+
+                self.server_outbuf.extend(
+                    format!(
+                        "{}: {}\r\n",
+                        PROXY_AUTHORIZATION,
+                        response.to_header_string()
+                    )
+                    .as_bytes(),
+                );
+            }
+            AuthenticationScheme::Basic => {
+                let cred = format!("{}:{}", credentials.username, credentials.password);
+                let auth_b64 = base64::engine::general_purpose::STANDARD.encode(cred);
+                self.server_outbuf
+                    .extend(format!("{}: Basic {}\r\n", PROXY_AUTHORIZATION, auth_b64).as_bytes());
+            }
+            AuthenticationScheme::None => {}
         }
+
+        Ok(())
     }
 
     fn state_change(&mut self) -> Result<(), Error> {
-        let http_len = "HTTP/1.1 200".len();
         match self.state {
-            HttpState::ExpectStatusCode if self.server_inbuf.len() > http_len => {
-                let status_line: Vec<u8> =
-                    self.server_inbuf.range(0..http_len + 1).copied().collect();
-                let slice = &status_line.as_slice()[0.."HTTP/1.1 2".len()];
-                if slice != b"HTTP/1.1 2" && slice != b"HTTP/1.0 2"
-                    || self.server_inbuf[http_len] != b' '
-                {
-                    let status_str = String::from_utf8_lossy(&status_line.as_slice()[0..http_len]);
-                    let e =
-                        format!("Expected success status code. Server replied with {status_str}.");
-                    return Err(e.into());
-                }
-                self.state = HttpState::ExpectResponse;
-                return self.state_change();
-            }
-            HttpState::ExpectResponse => {
-                let mut counter = 0usize;
-                for b_ref in self.server_inbuf.iter() {
-                    let b = *b_ref;
+            HttpState::ExpectResponseHeaders => {
+                while self.counter < self.server_inbuf.len() {
+                    let b = self.server_inbuf[self.counter];
                     if b == b'\n' {
                         self.crlf_state += 1;
                     } else if b != b'\r' {
                         self.crlf_state = 0;
                     }
-                    counter += 1;
 
+                    self.counter += 1;
                     if self.crlf_state == 2 {
-                        self.server_inbuf.drain(0..counter);
+                        break;
+                    }
+                }
+
+                if self.crlf_state != 2 {
+                    // Waiting for the end of the headers yet
+                    return Ok(());
+                }
+
+                self.counter = 0;
+                self.crlf_state = 0;
+
+                let mut headers = [httparse::EMPTY_HEADER; 16];
+                let mut res = Response::new(&mut headers);
+
+                // First make the buffer contiguous
+                let slice = self.server_inbuf.make_contiguous();
+                let status = res.parse(slice)?;
+                if status.is_partial() {
+                    // TODO: Optimize in order to detect 200
+                    return Ok(());
+                }
+                let len = status.unwrap();
+                let status_code = res.code.unwrap();
+                let version = res.version.unwrap();
+
+                if status_code == 200 {
+                    // Connection successful
+                    self.state = HttpState::Established;
+                    self.server_inbuf.clear();
+
+                    self.server_outbuf.append(&mut self.data_buf);
+                    self.data_buf.clear();
+
+                    return self.state_change();
+                }
+
+                if status_code != 407 {
+                    let e =
+                        format!("Expected success status code. Server replied with {status_code} [Reason: {}].", res.reason.unwrap());
+                    return Err(e.into());
+                }
+
+                let headers_map: HashMap<UniCase<&str>, &[u8], RandomState> =
+                    HashMap::from_iter(headers.map(|x| (UniCase::new(x.name), x.value)));
+
+                let Some(auth_data) = headers_map.get(&UniCase::new(PROXY_AUTHENTICATE)) else {
+                    return Err("Proxy requires auth but doesn't send it datails".into());
+                };
+
+                if !auth_data[..6].eq_ignore_ascii_case(b"digest") {
+                    // Fail to auth and the scheme isn't in the
+                    // supported auth method schemes
+                    return Err("Bad credentials".into());
+                }
+
+                // Analize challenge params
+                let data = str::from_utf8(auth_data)?;
+                let state = digest_auth::parse(data)?;
+                if self.before && !state.stale {
+                    return Err("Bad credentials".into());
+                }
+
+                // Update the digest state
+                self.digest_state.replace(Some(state));
+                self.before = true;
+
+                let closed = match headers_map.get(&UniCase::new(CONNECTION)) {
+                    Some(conn_header) => conn_header.eq_ignore_ascii_case(b"close"),
+                    None => false,
+                };
 
-                        self.server_outbuf.append(&mut self.data_buf);
-                        self.data_buf.clear();
+                if closed || version == 0 {
+                    // Close mio stream connection and reset it
+                    // Reset all the buffers
+                    self.server_inbuf.clear();
+                    self.server_outbuf.clear();
+                    self.send_tunnel_request()?;
 
-                        self.state = HttpState::Established;
-                        return self.state_change();
+                    self.state = HttpState::Reset;
+                    return Ok(());
+                }
+
+                // The HTTP/1.1 expected to be keep alive waiting for the next frame so, we must
+                // compute the lenght of the response in order to detect the next frame (response)
+                // [RFC-9112](https://datatracker.ietf.org/doc/html/rfc9112#body.content-length)
+
+                // Transfer-Encoding isn't supported yet
+                if let Some(_) = headers_map.get(&UniCase::new(TRANSFER_ENCODING)) {
+                    unimplemented!("Header Transfer-Encoding not supported");
+                }
+
+                let content_length = match headers_map.get(&UniCase::new(CONTENT_LENGTH)) {
+                    Some(v) => {
+                        let value = str::from_utf8(v)?;
+
+                        // https://www.rfc-editor.org/rfc/rfc9110#section-5.6.1
+                        match value.parse::<usize>() {
+                            Ok(x) => x,
+                            Err(_) => {
+                                let mut it = value.split(',').map(|x| x.parse::<usize>());
+                                let f = it.next().unwrap()?;
+                                for k in it {
+                                    if k? != f {
+                                        return Err("Malformed response".into());
+                                    }
+                                }
+                                f
+                            }
+                        }
+                    }
+                    None => {
+                        // Close the connection by information miss
+                        self.server_inbuf.clear();
+                        self.server_outbuf.clear();
+                        self.send_tunnel_request()?;
+
+                        self.state = HttpState::Reset;
+                        return Ok(());
                     }
+                };
+
+                // Handshake state
+                self.state = HttpState::ExpectResponse;
+                self.skip = content_length + len;
+
+                return self.state_change();
+            }
+            HttpState::ExpectResponse => {
+                if self.skip > 0 {
+                    let cnt = self.skip.min(self.server_inbuf.len());
+                    self.server_inbuf.drain(..cnt);
+                    self.skip -= cnt;
                 }
 
-                self.server_inbuf.drain(0..counter);
+                if self.skip == 0 {
+                    // Expected to the server_inbuff to be empty
+
+                    // self.server_outbuf.append(&mut self.data_buf);
+                    // self.data_buf.clear();
+                    self.send_tunnel_request()?;
+                    self.state = HttpState::ExpectResponseHeaders;
+
+                    return self.state_change();
+                }
             }
             HttpState::Established => {
                 self.client_outbuf.extend(self.server_inbuf.iter());
@@ -110,6 +309,9 @@ impl HttpConnection {
                 self.server_inbuf.clear();
                 self.client_inbuf.clear();
             }
+            HttpState::Reset => {
+                self.state = HttpState::ExpectResponseHeaders;
+            }
             _ => {}
         }
         Ok(())
@@ -175,11 +377,16 @@ impl TcpProxy for HttpConnection {
             },
         }
     }
+
+    fn reset_connection(&self) -> bool {
+        self.state == HttpState::Reset
+    }
 }
 
 pub(crate) struct HttpManager {
     server: SocketAddr,
     credentials: Option<Credentials>,
+    digest_state: Rc<RefCell<Option<DigestState>>>,
 }
 
 impl ConnectionManager for HttpManager {
@@ -195,7 +402,11 @@ impl ConnectionManager for HttpManager {
         if connection.proto != IpProtocol::Tcp {
             return Ok(None);
         }
-        Ok(Some(Box::new(HttpConnection::new(connection, manager))))
+        Ok(Some(Box::new(HttpConnection::new(
+            connection,
+            manager,
+            self.digest_state.clone(),
+        )?)))
     }
 
     fn close_connection(&self, _: &Connection) {}
@@ -214,6 +425,7 @@ impl HttpManager {
         Rc::new(Self {
             server,
             credentials,
+            digest_state: Rc::new(RefCell::new(None)),
         })
     }
 }

src/lib.rs

@@ -110,15 +110,15 @@ impl Options {
 
 #[derive(Default, Clone, Debug)]
 pub struct Credentials {
-    pub(crate) username: Vec<u8>,
-    pub(crate) password: Vec<u8>,
+    pub(crate) username: String,
+    pub(crate) password: String,
 }
 
 impl Credentials {
     pub fn new(username: &str, password: &str) -> Self {
         Self {
-            username: username.as_bytes().to_vec(),
-            password: password.as_bytes().to_vec(),
+            username: String::from(username),
+            password: String::from(password),
         }
     }
 }

src/socks.rs

@@ -156,10 +156,10 @@ impl SocksConnection {
                 }
                 self.server_outbuf.extend(ip_vec);
                 if let Some(credentials) = credentials {
-                    self.server_outbuf.extend(&credentials.username);
+                    self.server_outbuf.extend(credentials.username.as_bytes());
                     if !credentials.password.is_empty() {
                         self.server_outbuf.push_back(b':');
-                        self.server_outbuf.extend(&credentials.password);
+                        self.server_outbuf.extend(credentials.password.as_bytes());
                     }
                 }
                 self.server_outbuf.push_back(0);
@@ -250,10 +250,10 @@ impl SocksConnection {
         let credentials = self.credentials.as_ref().unwrap_or(&tmp);
         self.server_outbuf
             .extend(&[1u8, credentials.username.len() as u8]);
-        self.server_outbuf.extend(&credentials.username);
+        self.server_outbuf.extend(credentials.username.as_bytes());
         self.server_outbuf
             .extend(&[credentials.password.len() as u8]);
-        self.server_outbuf.extend(&credentials.password);
+        self.server_outbuf.extend(credentials.password.as_bytes());
         self.state = SocksState::ReceiveAuthResponse;
         self.state_change()
     }
@@ -424,6 +424,10 @@ impl TcpProxy for SocksConnection {
             },
         }
     }
+
+    fn reset_connection(&self) -> bool {
+        false
+    }
 }
 
 pub struct SocksManager {

src/tun2proxy.rs

@@ -228,6 +228,7 @@ pub(crate) trait TcpProxy {
     fn peek_data(&mut self, dir: OutgoingDirection) -> OutgoingDataEvent;
     fn connection_established(&self) -> bool;
     fn have_data(&mut self, dir: Direction) -> bool;
+    fn reset_connection(&self) -> bool;
 }
 
 pub(crate) trait ConnectionManager {
@@ -291,7 +292,7 @@ impl<'a> TunToProxy<'a> {
         let mut virt = VirtualTunDevice::new(tun.capabilities());
         let gateway4: Ipv4Addr = Ipv4Addr::from_str("0.0.0.1")?;
         let gateway6: Ipv6Addr = Ipv6Addr::from_str("::1")?;
-        let mut iface = Interface::new(config, &mut virt);
+        let mut iface = Interface::new(config, &mut virt, smoltcp::time::Instant::now());
         iface.update_ip_addrs(|ip_addrs| {
             ip_addrs.push(IpCidr::new(gateway4.into(), 0)).unwrap();
             ip_addrs.push(IpCidr::new(gateway6.into(), 0)).unwrap()
@@ -699,6 +700,10 @@ impl<'a> TunToProxy<'a> {
             return Ok(());
         }
         let connection = conn_ref.unwrap().clone();
+        let server = self
+            .get_connection_manager(&connection)
+            .unwrap()
+            .get_server();
 
         (|| -> Result<(), Error> {
             if event.is_readable() || event.is_read_closed() {
@@ -737,6 +742,30 @@ impl<'a> TunToProxy<'a> {
                         return Ok(());
                     }
 
+                    // The handler request for reset the server connection
+                    if state.handler.reset_connection() {                        
+                        // Closes the connection with the proxy
+                        state.mio_stream.shutdown(Both)?;
+
+                        info!("RESETED {}", connection);
+
+                        // TODO: Improve the call upstairs
+                        state.mio_stream = TcpStream::connect(server)?;
+
+                        _ = self.poll.registry().deregister(&mut state.mio_stream);
+                        self.poll.registry().register(
+                            &mut state.mio_stream,
+                            state.token,
+                            Interest::WRITABLE,
+                        )?;
+
+                        state.wait_read = true;
+                        state.wait_write = true;
+                        state.close_state = 0;
+                        
+                        return Ok(());
+                    }
+
                     if read == 0 || event.is_read_closed() {
                         state.wait_read = false;
                         state.close_state |= SERVER_WRITE_CLOSED;