Initial QSfera import

Server/vendor/github.com/libregraph/lico/utils/origin.go

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2017-2019 Kopano and its licensors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package utils
+
+import (
+	"net/http"
+	"net/url"
+)
+
+// OriginFromRequestHeaders tries to find information about the origin from the
+// provided http.Header. It first looks into the Origin header field and if that
+// is not found it looks into the Referer header field. If both are not found
+// an empty string is returned.
+func OriginFromRequestHeaders(header http.Header) string {
+	origin := header.Get("Origin")
+	if origin == "" {
+		referer := header.Get("Referer")
+		if referer != "" {
+			refererURI, _ := url.Parse(referer)
+			origin = refererURI.Scheme + "://" + refererURI.Host
+		}
+	}
+
+	return origin
+}