Add list-sigs implementation

src/_parsers.py

@@ -337,6 +337,7 @@ def _is_allowed(input):
                          '--armour',
                          '--clearsign',
                          '--detach-sign',
+                         '--list-sigs',
                          '--sign',
                          '--verify',
                          ## i/o and files
@@ -499,7 +500,7 @@ def _sanitise(*args):
                                 log.debug("%s not file: %s" % (flag, val))
                         elif flag in ['--default-key', '--recipient',
                                       '--export', '--export-secret-keys',
-                                      '--delete-keys',
+                                      '--delete-keys', '--list-sigs',
                                       '--export-secret-subkeys',]:
                             if _is_hex(val):
                                 safe_option += (val + " ")

src/gnupg.py

@@ -1038,7 +1038,21 @@ use_agent: %s
         :returns: A dictionary whose keys are the original keyid parameters,
                   and whose values are lists of signatures.
         """
-        raise NotImplemented("Functionality for '--list-sigs' not implemented.")
+        if len(keyids) > self._batch_limit:
+            raise ValueError(
+                "List signatures is limited to %d keyids simultaneously"
+                % self._batch_limit)
+
+        args = ["--with-colons", "--fixed-list-mode", "--list-sigs"]
+
+        for key in keyids:
+            args.append(key)
+
+        proc = self._open_subprocess(args)
+
+        result = self._result_map['list'](self)
+        self._collect_output(proc, result, stdin=p.stdin)
+        return result
 
     def gen_key(self, input):
         """Generate a GnuPG key through batch file key generation. See