Add Seal option in the configuration file for journald-remote

While journal received remotely can be sealed, it can only be done
on the command line using --seal, so for consistency, we will
also permit to set it in the configuration file.

man/journal-remote.conf.xml

@@ -72,6 +72,13 @@
     <literal>[Remote]</literal> section:</para>
 
     <variablelist>
+      <varlistentry>
+        <term><varname>Seal=</varname></term>
+
+        <listitem><para>Periodically sign the data in the journal using Forward Secure Sealing.
+        </para></listitem>
+      </varlistentry>
+
 
       <varlistentry>
         <term><varname>SplitMode=</varname></term>

src/journal-remote/journal-remote.c

@@ -1181,6 +1181,7 @@ static DEFINE_CONFIG_PARSE_ENUM(config_parse_write_split_mode,
 
 static int parse_config(void) {
         const ConfigTableItem items[] = {
+                { "Remote",  "Seal",                   config_parse_bool,             0, &arg_seal       },
                 { "Remote",  "SplitMode",              config_parse_write_split_mode, 0, &arg_split_mode },
                 { "Remote",  "ServerKeyFile",          config_parse_path,             0, &arg_key        },
                 { "Remote",  "ServerCertificateFile",  config_parse_path,             0, &arg_cert       },

src/journal-remote/journal-remote.conf.in

@@ -1,4 +1,5 @@
 [Remote]
+# Seal=false
 # SplitMode=host
 # ServerKeyFile=@CERTIFICATEROOT@/private/journal-remote.pem
 # ServerCertificateFile=@CERTIFICATEROOT@/certs/journal-remote.pem