GODT-213: Message Builder

pkg/message/build_boundary.go

@@ -0,0 +1,43 @@
+// Copyright (c) 2021 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package message
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+)
+
+type boundary struct {
+	val string
+}
+
+func newBoundary(seed string) *boundary {
+	return &boundary{val: seed}
+}
+
+func (bw *boundary) gen() string {
+	hash := sha256.New()
+
+	if _, err := hash.Write([]byte(bw.val)); err != nil {
+		panic(err)
+	}
+
+	bw.val = hex.EncodeToString(hash.Sum(nil))
+
+	return bw.val
+}