Functionality for backend to retrieve passphrase adhoc on restore, which

is convenient for asymmetric gpg encryption.

Duplicati/Server/Database/Connection.cs

@@ -309,7 +309,7 @@ namespace Duplicati.Server.Database
             lock(m_lock)
             {
                 var bk = ReadFromDb(
-                    (rd) => new Schedule() {
+                    (rd) => new Schedule {
                         ID = ConvertToInt64(rd, 0),
                         Tags = (ConvertToString(rd, 1) ?? "").Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries),
                         Time = ConvertToDateTime(rd, 2),
@@ -322,7 +322,19 @@ namespace Duplicati.Server.Database
 
                 return bk;
             }
-        }        
+        }
+
+        internal Boolean IsPassphraseStored(long id)
+        {
+            lock (m_lock)
+            {
+                return ReadFromDb(
+                    (rd) => ConvertToBoolean(rd, 0)
+                    ,
+                    @"SELECT VALUE != """" FROM ""Option"" WHERE BackupID = ? AND NAME='passphrase'", id)
+                .FirstOrDefault();
+            }
+        }
 
         internal long[] GetScheduleIDsFromTags(string[] tags)
         {

Duplicati/Server/Runner.cs

@@ -183,18 +183,21 @@ namespace Duplicati.Server
                 filters);
         }
 
-        public static IRunnerData CreateRestoreTask(Duplicati.Server.Serialization.Interface.IBackup backup, string[] filters, DateTime time, string restoreTarget, bool overwrite, bool restore_permissions, bool skip_metadata)
+        public static IRunnerData CreateRestoreTask(Duplicati.Server.Serialization.Interface.IBackup backup, string[] filters, 
+                                                    DateTime time, string restoreTarget, bool overwrite, bool restore_permissions, 
+                                                    bool skip_metadata, string passphrase = null)
         {
-            var dict = new Dictionary<string, string>();
-            dict["time"] = Duplicati.Library.Utility.Utility.SerializeDateTime(time.ToUniversalTime());
+            var dict = new Dictionary<string, string>
+            {
+                ["time"] = Library.Utility.Utility.SerializeDateTime(time.ToUniversalTime()),
+                ["overwrite"] = overwrite? Boolean.TrueString : Boolean.FalseString,
+                ["restore-permissions"] = restore_permissions ? Boolean.TrueString : Boolean.FalseString,
+                ["skip-metadata"] = skip_metadata ? Boolean.TrueString : Boolean.FalseString,
+                ["passphrase"] = passphrase,
+                ["allow-passphrase-change"] = Boolean.TrueString
+            };
             if (!string.IsNullOrWhiteSpace(restoreTarget))
                 dict["restore-path"] = SpecialFolders.ExpandEnvironmentVariables(restoreTarget);
-            if (overwrite)
-                dict["overwrite"] = "true";
-            if (restore_permissions)
-                dict["restore-permissions"] = "true";
-            if (skip_metadata)
-                dict["skip-metadata"] = "true";
 
             return CreateTask(
                 DuplicatiOperation.Restore,

Duplicati/Server/WebServer/RESTMethods/Backup.cs

@@ -187,7 +187,9 @@ namespace Duplicati.Server.WebServer.RESTMethods
             var input = info.Request.Form;
 
             string[] filters = parsePaths(input["paths"].Value ?? string.Empty);
-            
+
+            var passphrase = string.IsNullOrEmpty(input["passphrase"].Value) ? null : input["passphrase"].Value;
+
             var time = Duplicati.Library.Utility.Timeparser.ParseTimeInterval(input["time"].Value, DateTime.Now);
             var restoreTarget = input["restore-path"].Value;
             var overwrite = Duplicati.Library.Utility.Utility.ParseBool(input["overwrite"].Value, false);
@@ -195,7 +197,7 @@ namespace Duplicati.Server.WebServer.RESTMethods
             var permissions = Duplicati.Library.Utility.Utility.ParseBool(input["permissions"].Value, false);
             var skip_metadata = Duplicati.Library.Utility.Utility.ParseBool(input["skip-metadata"].Value, false);
 
-            var task = Runner.CreateRestoreTask(backup, filters, time, restoreTarget, overwrite, permissions, skip_metadata);
+            var task = Runner.CreateRestoreTask(backup, filters, time, restoreTarget, overwrite, permissions, skip_metadata, passphrase);
 
             Program.WorkThread.AddTask(task);
 

Duplicati/Server/WebServer/RESTMethods/Backups.cs

@@ -26,6 +26,7 @@ namespace Duplicati.Server.WebServer.RESTMethods
     {
         public class AddOrUpdateBackupData
         {
+            public Boolean HasPassphraseStored { get; set;}
             public Database.Schedule Schedule { get; set;}
             public Database.Backup Backup { get; set;}
         }
@@ -36,7 +37,8 @@ namespace Duplicati.Server.WebServer.RESTMethods
             var backups = Program.DataConnection.Backups;
 
             var all = from n in backups
-                select new AddOrUpdateBackupData() {
+                select new AddOrUpdateBackupData {
+                HasPassphraseStored = Program.DataConnection.IsPassphraseStored(long.Parse(n.ID)),
                 Backup = (Database.Backup)n,
                 Schedule = 
                     (from x in schedules