Initial commit

application/controller/common.go

@@ -0,0 +1,75 @@
+// Sshwifty - A Web SSH client
+//
+// Copyright (C) 2019 Rui NI <nirui@gmx.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package controller
+
+import (
+	"net/http"
+	"strings"
+	"time"
+)
+
+func clientSupportGZIP(r *http.Request) bool {
+	// Should be good enough
+	return strings.Contains(r.Header.Get("Accept-Encoding"), "gzip")
+}
+
+func clientContentEtagIsValid(r *http.Request, eTag string) bool {
+	d := r.Header.Get("If-None-Match")
+
+	if len(d) < 0 {
+		return false
+	}
+
+	dStart := 0
+	qETag := "\"" + eTag + "\""
+
+	for {
+		dIdx := strings.Index(d[dStart:], ",")
+
+		if dIdx < 0 {
+			return strings.Contains(d[dStart:], qETag) ||
+				strings.Contains(d[dStart:], "*")
+		}
+
+		if strings.Contains(d[dStart:dStart+dIdx], qETag) {
+			return true
+		}
+
+		if strings.Contains(d[dStart:dStart+dIdx], "*") {
+			return true
+		}
+
+		dStart += dIdx + 1
+	}
+}
+
+func clientContentModifiedSince(r *http.Request, mod time.Time) bool {
+	d := r.Header.Get("If-Modified-Since")
+
+	if len(d) < 0 {
+		return false
+	}
+
+	dt, dtErr := time.Parse(time.RFC1123, d)
+
+	if dtErr != nil {
+		return false
+	}
+
+	return !mod.Before(dt)
+}