example: add user ID

* Added script to add a UID to an existing key.

lang/python/examples/howto/add-userid.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from __future__ import absolute_import, division, unicode_literals
+
+# Copyright (C) 2018 Ben McGinnes <ben@gnupg.org>
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation; either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU General Public License and the GNU
+# Lesser General Public Licensefor more details.
+#
+# You should have received a copy of the GNU General Public License and the GNU
+# Lesser General Public along with this program; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import gpg
+import os.path
+
+print("""
+This script adds a new user ID to an existing key.
+
+The gpg-agent and pinentry are invoked to enter the passphrase.
+""")
+
+c = gpg.Context()
+
+homedir = input("Enter the GPG configuration directory path (optional): ")
+fpr0 = input("Enter the fingerprint of the key to modify: ")
+uid_name = input("Enter the name of the user ID: ")
+uid_email = input("Enter the email address of the user ID: ")
+uid_cmnt = input("Enter a comment to include (optional): ")
+
+if homedir.startswith("~"):
+    if os.path.exists(os.path.expanduser(homedir)) is True:
+        c.home_dir = os.path.expanduser(homedir)
+    else:
+        pass
+elif os.path.exists(homedir) is True:
+    c.home_dir = homedir
+else:
+    pass
+
+fpr = "".join(fpr0.split())
+
+if len(uid_cmnt) > 0:
+    userid = "{0} ({1}) <{2}>".format(uid_name, uid_cmnt, uid_email)
+else:
+    userid = "{0} <{2}>".format(uid_name, uid_email)
+
+key = c.get_key(fpr, secret=True)
+c.key_add_uid(key, userid)