Function verifyServerResponse

dial.go:242–268

(opts *DialOptions, copts *compressionOptions, secWebSocketKey string, resp *http.Response)

}

func verifyServerResponse(opts *DialOptions, copts *compressionOptions, secWebSocketKey string, resp *http.Response) (*compressionOptions, error) {
	if resp.StatusCode != http.StatusSwitchingProtocols {
		return nil, fmt.Errorf("expected handshake response status code %v but got %v", http.StatusSwitchingProtocols, resp.StatusCode)
	}

	if !headerContainsTokenIgnoreCase(resp.Header, "Connection", "Upgrade") {
		return nil, fmt.Errorf("WebSocket protocol violation: Connection header %q does not contain Upgrade", resp.Header.Get("Connection"))
	}

	if !headerContainsTokenIgnoreCase(resp.Header, "Upgrade", "WebSocket") {
		return nil, fmt.Errorf("WebSocket protocol violation: Upgrade header %q does not contain websocket", resp.Header.Get("Upgrade"))
	}

	if resp.Header.Get("Sec-WebSocket-Accept") != secWebSocketAccept(secWebSocketKey) {
		return nil, fmt.Errorf("WebSocket protocol violation: invalid Sec-WebSocket-Accept %q, key %q",
			resp.Header.Get("Sec-WebSocket-Accept"),
			secWebSocketKey,
		)
	}

	err := verifySubprotocol(opts.Subprotocols, resp)
	if err != nil {
		return nil, err
	}

	return verifyServerExtensions(copts, resp.Header)
}

func verifySubprotocol(subprotos []string, resp *http.Response) error {
	proto := resp.Header.Get("Sec-WebSocket-Protocol")