Add simple master key provider for secret encryption

services/secrets/masterkey_plain.go

@@ -0,0 +1,59 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package secrets
+
+import (
+	"code.gitea.io/gitea/modules/generate"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+type plainMasterKeyProvider struct {
+	key []byte
+}
+
+// NewPlainMasterKeyProvider returns unsecured static master key provider
+func NewPlainMasterKeyProvider() MasterKeyProvider {
+	return &plainMasterKeyProvider{}
+}
+
+// Init initializes master key provider
+func (k *plainMasterKeyProvider) Init() error {
+	return k.Unseal(nil)
+}
+
+// GenerateMasterKey generates a new master key and returns secret or secrets for unsealing
+func (k *plainMasterKeyProvider) GenerateMasterKey() ([][]byte, error) {
+	key, err := generate.NewMasterKey()
+	if err != nil {
+		return nil, err
+	}
+	k.key = key
+	return [][]byte{key}, nil
+}
+
+// Unseal master key by providing unsealing secret
+func (k *plainMasterKeyProvider) Unseal(secret []byte) error {
+	k.key = setting.MasterKey
+	return nil
+}
+
+// Seal master key
+func (k *plainMasterKeyProvider) Seal() error {
+	k.key = nil
+	return nil
+}
+
+// IsSealed returns if master key is sealed
+func (k *plainMasterKeyProvider) IsSealed() bool {
+	return len(k.key) == 0
+}
+
+// GetMasterKey returns master key
+func (k *plainMasterKeyProvider) GetMasterKey() ([]byte, error) {
+	if k.IsSealed() {
+		return nil, ErrMasterKeySealed
+	}
+	return k.key, nil
+}