Function web_socket::handshake::response

source · 
pub fn response(
    sec_ws_key: impl AsRef<str>,
    headers: impl IntoIterator<Item = impl Header>
) -> String
Expand description

Server handshake response

When the server receives the handshake request, It should send back a special response that indicates that the protocol will be changing from HTTP to WebSocket.

The Sec-WebSocket-Accept header is important in that the server must derive it from the Sec-WebSocket-Key that the client sent to it.

Example

let res = [
    "HTTP/1.1 101 Switching Protocols",
    "Upgrade: websocket",
    "Connection: Upgrade",
    "Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=",
    "",
    ""
];
let field: Option<(&str, &str)> = None;
assert_eq!(web_socket::handshake::response("dGhlIHNhbXBsZSBub25jZQ==", field), res.join("\r\n"));

To get it, concatenate the client’s Sec-WebSocket-Key and the string “258EAFA5-E914-47DA-95CA-C5AB0DC85B11” together (it’s a Magic string), take the SHA-1 hash of the result, and return the base64 encoding of that hash.

  1. If the connection is happening on an HTTPS (HTTP-over-TLS) port, perform a TLS handshake over the connection. If this fails (e.g., the client indicated a host name in the extended client hello “server_name” extension that the server does not host), then close the connection.

  2. The server can perform additional client authentication, Or The server MAY redirect the client.

Note

  • Regular HTTP status codes can be used only before the handshake. After the handshake succeeds, you have to use a different set of codes (defined in section 7.4 of the spec)