//! Client handshake machine.
use std::borrow::Cow;
use std::io::{Read, Write};
use std::marker::PhantomData;
use base64;
use httparse::Status;
use httparse;
use rand;
use url::Url;
use error::{Error, Result};
use protocol::{WebSocket, Role};
use super::headers::{Headers, FromHttparse, MAX_HEADERS};
use super::machine::{HandshakeMachine, StageResult, TryParse};
use super::{MidHandshake, HandshakeRole, ProcessingResult, convert_key};
/// Client request.
#[derive(Debug)]
pub struct Request<'t> {
/// `ws://` or `wss://` URL to connect to.
pub url: Url,
/// Extra HTTP headers to append to the request.
pub extra_headers: Option<Vec<(Cow<'t, str>, Cow<'t, str>)>>,
}
impl<'t> Request<'t> {
/// Returns the GET part of the request.
fn get_path(&self) -> String {
if let Some(query) = self.url.query() {
format!("{path}?{query}", path = self.url.path(), query = query)
} else {
self.url.path().into()
}
}
/// Returns the host part of the request.
fn get_host(&self) -> String {
let host = self.url.host_str().expect("Bug: URL without host");
if let Some(port) = self.url.port() {
format!("{host}:{port}", host = host, port = port)
} else {
host.into()
}
}
/// Adds a WebSocket protocol to the request.
pub fn add_protocol(&mut self, protocol: Cow<'t, str>) {
self.add_header(Cow::from("Sec-WebSocket-Protocol"), protocol);
}
/// Adds a custom header to the request.
pub fn add_header(&mut self, name: Cow<'t, str>, value: Cow<'t, str>) {
let mut headers = self.extra_headers.take().unwrap_or(vec![]);
headers.push((name, value));
self.extra_headers = Some(headers);
}
}
impl From<Url> for Request<'static> {
fn from(value: Url) -> Self {
Request {
url: value,
extra_headers: None,
}
}
}
/// Client handshake role.
#[derive(Debug)]
pub struct ClientHandshake<S> {
verify_data: VerifyData,
_marker: PhantomData<S>,
}
impl<S: Read + Write> ClientHandshake<S> {
/// Initiate a client handshake.
pub fn start(stream: S, request: Request) -> MidHandshake<Self> {
let key = generate_key();
let machine = {
let mut req = Vec::new();
write!(req, "\
GET {path} HTTP/1.1\r\n\
Host: {host}\r\n\
Connection: upgrade\r\n\
Upgrade: websocket\r\n\
Sec-WebSocket-Version: 13\r\n\
Sec-WebSocket-Key: {key}\r\n",
host = request.get_host(), path = request.get_path(), key = key).unwrap();
if let Some(eh) = request.extra_headers {
for (k, v) in eh {
write!(req, "{}: {}\r\n", k, v).unwrap();
}
}
write!(req, "\r\n").unwrap();
HandshakeMachine::start_write(stream, req)
};
let client = {
let accept_key = convert_key(key.as_ref()).unwrap();
ClientHandshake {
verify_data: VerifyData { accept_key },
_marker: PhantomData,
}
};
trace!("Client handshake initiated.");
MidHandshake { role: client, machine: machine }
}
}
impl<S: Read + Write> HandshakeRole for ClientHandshake<S> {
type IncomingData = Response;
type InternalStream = S;
type FinalResult = (WebSocket<S>, Response);
fn stage_finished(&mut self, finish: StageResult<Self::IncomingData, Self::InternalStream>)
-> Result<ProcessingResult<Self::InternalStream, Self::FinalResult>>
{
Ok(match finish {
StageResult::DoneWriting(stream) => {
ProcessingResult::Continue(HandshakeMachine::start_read(stream))
}
StageResult::DoneReading { stream, result, tail, } => {
self.verify_data.verify_response(&result)?;
debug!("Client handshake done.");
ProcessingResult::Done((WebSocket::from_partially_read(stream, tail, Role::Client),
result))
}
})
}
}
/// Information for handshake verification.
#[derive(Debug)]
struct VerifyData {
/// Accepted server key.
accept_key: String,
}
impl VerifyData {
pub fn verify_response(&self, response: &Response) -> Result<()> {
// 1. If the status code received from the server is not 101, the
// client handles the response per HTTP [RFC2616] procedures. (RFC 6455)
if response.code != 101 {
return Err(Error::Http(response.code));
}
// 2. If the response lacks an |Upgrade| header field or the |Upgrade|
// header field contains a value that is not an ASCII case-
// insensitive match for the value "websocket", the client MUST
// _Fail the WebSocket Connection_. (RFC 6455)
if !response.headers.header_is_ignore_case("Upgrade", "websocket") {
return Err(Error::Protocol("No \"Upgrade: websocket\" in server reply".into()));
}
// 3. If the response lacks a |Connection| header field or the
// |Connection| header field doesn't contain a token that is an
// ASCII case-insensitive match for the value "Upgrade", the client
// MUST _Fail the WebSocket Connection_. (RFC 6455)
if !response.headers.header_is_ignore_case("Connection", "Upgrade") {
return Err(Error::Protocol("No \"Connection: upgrade\" in server reply".into()));
}
// 4. If the response lacks a |Sec-WebSocket-Accept| header field or
// the |Sec-WebSocket-Accept| contains a value other than the
// base64-encoded SHA-1 of ... the client MUST _Fail the WebSocket
// Connection_. (RFC 6455)
if !response.headers.header_is("Sec-WebSocket-Accept", &self.accept_key) {
return Err(Error::Protocol("Key mismatch in Sec-WebSocket-Accept".into()));
}
// 5. If the response includes a |Sec-WebSocket-Extensions| header
// field and this header field indicates the use of an extension
// that was not present in the client's handshake (the server has
// indicated an extension not requested by the client), the client
// MUST _Fail the WebSocket Connection_. (RFC 6455)
// TODO
// 6. If the response includes a |Sec-WebSocket-Protocol| header field
// and this header field indicates the use of a subprotocol that was
// not present in the client's handshake (the server has indicated a
// subprotocol not requested by the client), the client MUST _Fail
// the WebSocket Connection_. (RFC 6455)
// TODO
Ok(())
}
}
/// Server response.
#[derive(Debug)]
pub struct Response {
/// HTTP response code of the response.
pub code: u16,
/// Received headers.
pub headers: Headers,
}
impl TryParse for Response {
fn try_parse(buf: &[u8]) -> Result<Option<(usize, Self)>> {
let mut hbuffer = [httparse::EMPTY_HEADER; MAX_HEADERS];
let mut req = httparse::Response::new(&mut hbuffer);
Ok(match req.parse(buf)? {
Status::Partial => None,
Status::Complete(size) => Some((size, Response::from_httparse(req)?)),
})
}
}
impl<'h, 'b: 'h> FromHttparse<httparse::Response<'h, 'b>> for Response {
fn from_httparse(raw: httparse::Response<'h, 'b>) -> Result<Self> {
if raw.version.expect("Bug: no HTTP version") < /*1.*/1 {
return Err(Error::Protocol("HTTP version should be 1.1 or higher".into()));
}
Ok(Response {
code: raw.code.expect("Bug: no HTTP response code"),
headers: Headers::from_httparse(raw.headers)?,
})
}
}
/// Generate a random key for the `Sec-WebSocket-Key` header.
fn generate_key() -> String {
// a base64-encoded (see Section 4 of [RFC4648]) value that,
// when decoded, is 16 bytes in length (RFC 6455)
let r: [u8; 16] = rand::random();
base64::encode(&r)
}
#[cfg(test)]
mod tests {
use super::{Response, generate_key};
use super::super::machine::TryParse;
#[test]
fn random_keys() {
let k1 = generate_key();
println!("Generated random key 1: {}", k1);
let k2 = generate_key();
println!("Generated random key 2: {}", k2);
assert_ne!(k1, k2);
assert_eq!(k1.len(), k2.len());
assert_eq!(k1.len(), 24);
assert_eq!(k2.len(), 24);
assert!(k1.ends_with("=="));
assert!(k2.ends_with("=="));
assert!(k1[..22].find("=").is_none());
assert!(k2[..22].find("=").is_none());
}
#[test]
fn response_parsing() {
const DATA: &'static [u8] = b"HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n";
let (_, resp) = Response::try_parse(DATA).unwrap().unwrap();
assert_eq!(resp.code, 200);
assert_eq!(resp.headers.find_first("Content-Type"), Some(&b"text/html"[..]));
}
}