Remove HTTP server usage of (*http.Request).PathValue and clarify req…

…uirements in godoc

Signed-off-by: Ben Krieger <[email protected]>

http/handler.go

@@ -24,7 +24,8 @@ import (
 const bearerPrefix = "Bearer "
 
 // Handler implements http.Handler and responds to all DI, TO1, and TO2 message
-// types.
+// types. It is expected that the request will use the POST method and the path
+// will be of the form "/fdo/$VER/msg/$MSG".
 type Handler struct {
 	Tokens protocol.TokenService
 
@@ -38,6 +39,24 @@ type Handler struct {
 	MaxContentLength int64
 }
 
+func msgTypeFromPath(w http.ResponseWriter, r *http.Request) (uint8, bool) {
+	if r.Method != http.MethodPost {
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		return 0, false
+	}
+	path := strings.TrimPrefix(r.URL.Path, "/fdo/101/msg/")
+	if strings.Contains(path, "/") {
+		w.WriteHeader(http.StatusNotFound)
+		return 0, false
+	}
+	typ, err := strconv.ParseUint(path, 10, 8)
+	if err != nil {
+		writeErr(w, 0, fmt.Errorf("invalid message type"))
+		return 0, false
+	}
+	return uint8(typ), true
+}
+
 func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if h.Tokens == nil {
 		panic("token service not set")

http/http_test.go

@@ -5,7 +5,6 @@ package http_test
 
 import (
 	"net/http"
-	"path"
 	"testing"
 
 	"github.com/fido-device-onboard/go-fdo"
@@ -51,7 +50,6 @@ type transport struct {
 
 // Assume request is well-formed and ignore timeouts, retries, etc.
 func (tr *transport) RoundTrip(req *http.Request) (*http.Response, error) {
-	setPathValue(req, "msg", path.Base(req.URL.Path))
 	rr := new(httputil.ResponseRecorder)
 	tr.Handler.ServeHTTP(rr, req)
 	resp := rr.Result()

http/util.go

@@ -7,24 +7,13 @@ package http
 
 import (
 	"bytes"
-	"fmt"
 	"io"
 	"log/slog"
 	"net/http"
 	"net/http/httptest"
 	"net/http/httputil"
-	"strconv"
 )
 
-func msgTypeFromPath(w http.ResponseWriter, r *http.Request) (uint8, bool) {
-	typ, err := strconv.ParseUint(r.PathValue("msg"), 10, 8)
-	if err != nil {
-		writeErr(w, 0, fmt.Errorf("invalid message type"))
-		return 0, false
-	}
-	return uint8(typ), true
-}
-
 func debugRequest(w http.ResponseWriter, r *http.Request, handler http.HandlerFunc) {
 	if !debugEnabled() {
 		handler.ServeHTTP(w, r)

http/util_tinygo.go

@@ -11,30 +11,11 @@ import (
 	"io"
 	"log/slog"
 	"net/http"
-	"strconv"
 	"strings"
 
 	"github.com/fido-device-onboard/go-fdo/http/internal/httputil"
 )
 
-func msgTypeFromPath(w http.ResponseWriter, r *http.Request) (uint8, bool) {
-	if r.Method != http.MethodPost {
-		w.WriteHeader(http.StatusMethodNotAllowed)
-		return 0, false
-	}
-	path := strings.TrimPrefix(r.URL.Path, "/fdo/101/msg/")
-	if strings.Contains(path, "/") {
-		w.WriteHeader(http.StatusNotFound)
-		return 0, false
-	}
-	typ, err := strconv.ParseUint(path, 10, 8)
-	if err != nil {
-		writeErr(w, 0, fmt.Errorf("invalid message type"))
-		return 0, false
-	}
-	return uint8(typ), true
-}
-
 func debugRequest(w http.ResponseWriter, r *http.Request, handler http.HandlerFunc) {
 	if !debugEnabled() {
 		handler(w, r)