async_ws/
http.rs

1use http::request::Builder;
2use http::{HeaderValue, Method, Request, Response, StatusCode};
3use rand::{thread_rng, Rng};
4use ring::digest::{Context, SHA1_FOR_LEGACY_USE_ONLY};
5
6pub fn upgrade_request() -> Builder {
7    let mut nonce = [0u8; 16];
8    thread_rng().fill(&mut nonce);
9    Request::builder()
10        .method(Method::GET)
11        .header("Connection", "Upgrade")
12        .header("Upgrade", "websocket")
13        .header("Sec-WebSocket-Version", "13")
14        .header("Sec-WebSocket-Key", base64::encode(nonce))
15}
16
17pub fn is_upgrade_request<T>(request: &Request<T>) -> bool {
18    request.method() == http::Method::GET
19        && request
20            .headers()
21            .get("Connection")
22            .iter()
23            .flat_map(|v| v.as_bytes().split(|&c| c == b' ' || c == b','))
24            .filter(|h| h.eq_ignore_ascii_case(b"Upgrade"))
25            .next()
26            .is_some()
27        && request
28            .headers()
29            .get("Upgrade")
30            .filter(|v| v.as_bytes().eq_ignore_ascii_case(b"websocket"))
31            .is_some()
32        && request
33            .headers()
34            .get("Sec-WebSocket-Version")
35            .map(HeaderValue::as_bytes)
36            == Some(b"13")
37        && request.headers().get("Sec-WebSocket-Key").is_some()
38}
39
40pub fn upgrade_response<T>(request: &Request<T>) -> Option<Response<()>> {
41    let challenge = match (
42        is_upgrade_request(request),
43        request.headers().get("Sec-WebSocket-Key"),
44    ) {
45        (false, _) | (true, None) => return None,
46        (true, Some(challenge)) => challenge.as_bytes(),
47    };
48
49    let response = Response::builder()
50        .status(StatusCode::SWITCHING_PROTOCOLS)
51        .version(request.version())
52        .header("Connection", "Upgrade")
53        .header("Upgrade", "websocket")
54        .header(
55            "Sec-WebSocket-Accept",
56            upgrade_challenge_response(challenge),
57        )
58        .body(())
59        .unwrap();
60    Some(response)
61}
62
63pub fn check_upgrade_response<T, U>(request: &Request<T>, response: &Response<U>) -> bool {
64    let challenge = match (
65        is_upgrade_request(request),
66        request.headers().get("Sec-WebSocket-Key"),
67    ) {
68        (false, _) | (true, None) => return false,
69        (true, Some(challenge)) => challenge.as_bytes(),
70    };
71    response.status() == StatusCode::SWITCHING_PROTOCOLS
72        && response
73            .headers()
74            .get("Connection")
75            .filter(|v| v.as_bytes().eq_ignore_ascii_case(b"Upgrade"))
76            .is_some()
77        && response
78            .headers()
79            .get("Upgrade")
80            .filter(|v| v.as_bytes().eq_ignore_ascii_case(b"websocket"))
81            .is_some()
82        && response
83            .headers()
84            .get("Sec-WebSocket-Accept")
85            .map(HeaderValue::as_bytes)
86            == Some(upgrade_challenge_response(challenge).as_bytes())
87}
88
89fn upgrade_challenge_response(challenge: &[u8]) -> String {
90    let mut ctx = Context::new(&SHA1_FOR_LEGACY_USE_ONLY);
91    ctx.update(challenge);
92    ctx.update(b"258EAFA5-E914-47DA-95CA-C5AB0DC85B11");
93    base64::encode(ctx.finish())
94}
95
96#[cfg(test)]
97mod tests {
98    use crate::http::upgrade_challenge_response;
99
100    #[test]
101    fn challenge_response() {
102        assert_eq!(
103            upgrade_challenge_response(b"dGhlIHNhbXBsZSBub25jZQ=="),
104            "s3pPLMBiTxaQ9kYGzzhZRbK+xOo="
105        );
106    }
107}
async_ws/http.rs

async_ws/
http.rs
