Add hysteria2 protocol

transport/hysteria2/internal/protocol/http.go

@@ -0,0 +1,68 @@
+package protocol
+
+import (
+	"net/http"
+	"strconv"
+)
+
+const (
+	URLHost = "hysteria"
+	URLPath = "/auth"
+
+	RequestHeaderAuth        = "Hysteria-Auth"
+	ResponseHeaderUDPEnabled = "Hysteria-UDP"
+	CommonHeaderCCRX         = "Hysteria-CC-RX"
+	CommonHeaderPadding      = "Hysteria-Padding"
+
+	StatusAuthOK = 233
+)
+
+// AuthRequest is what client sends to server for authentication.
+type AuthRequest struct {
+	Auth string
+	Rx   uint64 // 0 = unknown, client asks server to use bandwidth detection
+}
+
+// AuthResponse is what server sends to client when authentication is passed.
+type AuthResponse struct {
+	UDPEnabled bool
+	Rx         uint64 // 0 = unlimited
+	RxAuto     bool   // true = server asks client to use bandwidth detection
+}
+
+func AuthRequestFromHeader(h http.Header) AuthRequest {
+	rx, _ := strconv.ParseUint(h.Get(CommonHeaderCCRX), 10, 64)
+	return AuthRequest{
+		Auth: h.Get(RequestHeaderAuth),
+		Rx:   rx,
+	}
+}
+
+func AuthRequestToHeader(h http.Header, req AuthRequest) {
+	h.Set(RequestHeaderAuth, req.Auth)
+	h.Set(CommonHeaderCCRX, strconv.FormatUint(req.Rx, 10))
+	h.Set(CommonHeaderPadding, authRequestPadding.String())
+}
+
+func AuthResponseFromHeader(h http.Header) AuthResponse {
+	resp := AuthResponse{}
+	resp.UDPEnabled, _ = strconv.ParseBool(h.Get(ResponseHeaderUDPEnabled))
+	rxStr := h.Get(CommonHeaderCCRX)
+	if rxStr == "auto" {
+		// Special case for server requesting client to use bandwidth detection
+		resp.RxAuto = true
+	} else {
+		resp.Rx, _ = strconv.ParseUint(rxStr, 10, 64)
+	}
+	return resp
+}
+
+func AuthResponseToHeader(h http.Header, resp AuthResponse) {
+	h.Set(ResponseHeaderUDPEnabled, strconv.FormatBool(resp.UDPEnabled))
+	if resp.RxAuto {
+		h.Set(CommonHeaderCCRX, "auto")
+	} else {
+		h.Set(CommonHeaderCCRX, strconv.FormatUint(resp.Rx, 10))
+	}
+	h.Set(CommonHeaderPadding, authResponsePadding.String())
+}