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rama_http_headers/common/
sec_websocket_accept.rs

1use base64::Engine;
2use base64::engine::general_purpose::STANDARD as ENGINE;
3use rama_core::bytes::Bytes;
4use rama_core::error::{BoxError, ErrorContext as _};
5use rama_http_types::HeaderValue;
6use sha1::{Digest, Sha1};
7
8use super::SecWebSocketKey;
9
10/// The `Sec-WebSocket-Accept` header.
11///
12/// This header is used in the WebSocket handshake, sent back by the
13/// server indicating a successful handshake. It is a signature
14/// of the `Sec-WebSocket-Key` header.
15///
16/// # Example
17///
18/// ```no_run
19/// use rama_http_headers::{SecWebSocketAccept, SecWebSocketKey};
20///
21/// let sec_key: SecWebSocketKey = /* from request headers */
22/// #    unimplemented!();
23///
24/// let sec_accept = SecWebSocketAccept::try_from(sec_key).unwrap();
25/// ```
26#[derive(Clone, Debug, PartialEq, Eq, Hash)]
27pub struct SecWebSocketAccept(HeaderValue);
28
29derive_header! {
30    SecWebSocketAccept(_),
31    name: SEC_WEBSOCKET_ACCEPT
32}
33
34impl TryFrom<SecWebSocketKey> for SecWebSocketAccept {
35    type Error = BoxError;
36
37    fn try_from(key: SecWebSocketKey) -> Result<Self, Self::Error> {
38        try_sign(key.0.as_bytes())
39    }
40}
41
42fn try_sign(key: &[u8]) -> Result<SecWebSocketAccept, BoxError> {
43    let mut sha1 = Sha1::default();
44    sha1.update(key);
45    sha1.update(&b"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"[..]);
46    let b64 = Bytes::from(ENGINE.encode(sha1.finalize()));
47
48    let val =
49        HeaderValue::from_maybe_shared(b64).context("create header value from base64 signature")?;
50
51    Ok(SecWebSocketAccept(val))
52}
53
54#[cfg(test)]
55mod tests {
56    use super::super::{test_decode, test_encode};
57    use super::*;
58
59    #[test]
60    fn key_to_accept() {
61        // From https://tools.ietf.org/html/rfc6455#section-1.2
62        let key = test_decode::<SecWebSocketKey>(&["dGhlIHNhbXBsZSBub25jZQ=="]).expect("key");
63        let accept = SecWebSocketAccept::try_from(key).unwrap();
64        let headers = test_encode(accept);
65
66        assert_eq!(
67            headers["sec-websocket-accept"],
68            "s3pPLMBiTxaQ9kYGzzhZRbK+xOo="
69        );
70    }
71}