[#221] Unify source file naming

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

api/user_auth.go

@@ -0,0 +1,44 @@
+package api
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	"github.com/nspcc-dev/neofs-s3-gw/api/auth"
+	"github.com/nspcc-dev/neofs-s3-gw/api/errors"
+	"go.uber.org/zap"
+)
+
+// KeyWrapper is wrapper for context keys.
+type KeyWrapper string
+
+// BoxData is an ID used to store accessbox.Box in a context.
+var BoxData = KeyWrapper("__context_box_key")
+
+// AttachUserAuth adds user authentication via center to router using log for logging.
+func AttachUserAuth(router *mux.Router, center auth.Center, log *zap.Logger) {
+	router.Use(func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			var ctx context.Context
+			box, err := center.Authenticate(r)
+			if err != nil {
+				if err == auth.ErrNoAuthorizationHeader {
+					log.Debug("couldn't receive bearer token, using neofs-key")
+					ctx = r.Context()
+				} else {
+					log.Error("failed to pass authentication", zap.Error(err))
+					if _, ok := err.(errors.Error); !ok {
+						err = errors.GetAPIError(errors.ErrAccessDenied)
+					}
+					WriteErrorResponse(w, GetReqInfo(r.Context()), err)
+					return
+				}
+			} else {
+				ctx = context.WithValue(r.Context(), BoxData, box)
+			}
+
+			h.ServeHTTP(w, r.WithContext(ctx))
+		})
+	})
+}