Don't specify a keyserver if a blank value is configured.

This is useful on systems like Debian 9, which have a default keyserver
configured system-wide.

CHANGELOG.md

@@ -8,6 +8,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 
 * Internal footer: to be appended to each email that is sent to a subscribed address.  Will not be included in messages to non-subscribed addresses. This change requires a change to the database, don't forget to run `schleuder install` after updating the code.
+* Optionally use an OS-wide defined keyserver by configuring a blank value for the keyserver.
 
 
 ### Changed

etc/schleuder.yml

@@ -16,6 +16,9 @@ log_level: warn
 #keyserver: hkps://hkps.pool.sks-keyservers.net
 # If you have gnupg 2.1 and TOR running locally, use a onion-keyserver:
 #keyserver: hkp://jirk5u4osbsr34t5.onion
+# If you have an OS-wide defined keyserver, specify a blank value to have that
+# one used:
+#keyserver: 
 # The default works for all supported versions of gnupg:
 keyserver: pool.sks-keyservers.net
 

lib/schleuder/gpgme/ctx.rb

@@ -98,7 +98,7 @@ module GPGME
     end
 
     def refresh_key(fingerprint)
-      args = "--keyserver #{Conf.keyserver} --refresh-keys #{fingerprint}"
+      args = "#{keyserver_arg} --refresh-keys #{fingerprint}"
       gpgerr, gpgout, exitcode = self.class.gpgcli(args)
 
       if exitcode > 0
@@ -135,13 +135,13 @@ module GPGME
     def fetch_key_gpg_arguments_for(input)
       case input
       when Conf::FINGERPRINT_REGEXP
-        "--keyserver #{Conf.keyserver} --recv-key #{input}"
+        "#{keyserver_arg} --recv-key #{input}"
       when /^http/
         "--fetch-key #{input}"
       when /@/
         # --recv-key doesn't work with email-addresses, so we use --locate-key
         # restricted to keyservers.
-        "--keyserver #{Conf.keyserver} --auto-key-locate keyserver --locate-key #{input}"
+        "#{keyserver_arg} --auto-key-locate keyserver --locate-key #{input}"
       else
         [nil, I18n.t("fetch_key.invalid_input")]
       end
@@ -248,5 +248,13 @@ module GPGME
         File.delete(path)
       end
     end
+
+    def keyserver_arg
+      if Conf.keyserver.present?
+        "--keyserver #{Conf.keyserver}"
+      else
+        ""
+      end
+    end
   end
 end

spec/schleuder/unit/gpgme_ctx.rb

@@ -168,4 +168,26 @@ describe GPGME::Ctx do
     expect(out.class).to eql(NilClass)
     expect(exitcode.class).to eql(Integer)
   end
+
+  context "#keyserver_arg" do
+    it "returns keyserver-args if a keyserver is configured" do
+      list = create(:list)
+
+      keyserver_args = list.gpg.send(:keyserver_arg)
+
+      expect(keyserver_args).to eql("--keyserver #{Conf.keyserver}")
+    end
+
+    it "returns a blank string if the keyserver-option is set to a blank value" do
+      oldval = Conf.instance.config['keyserver']
+      Conf.instance.config['keyserver'] = ''
+      list = create(:list)
+
+      keyserver_args = list.gpg.send(:keyserver_arg)
+
+      expect(keyserver_args).to eql("")
+
+      Conf.instance.config['keyserver'] = oldval
+    end
+  end
 end