example: python bindings

* lang/python/examples/howto/local-sign-group.py: locally sign every
  key in a group line except one's own keys.  Intended to address the
  sort of thing one might see on lists like PGPNET or other closed
  groups amongst activists, journalists, etc. where everyone encrypts
  to all recipients, but may not sign everyone's keys publicly..

Signed-off-by: Ben McGinnes <[email protected]>

1 files changed, 163 insertions, 0 deletions

diff --git a/lang/python/examples/howto/local-sign-group.py b/lang/python/examples/howto/local-sign-group.py
new file mode 100755
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+++ b/lang/python/examples/howto/local-sign-group.py
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+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from __future__ import absolute_import, division, unicode_literals
+
+import gpg
+import os.path
+import subprocess
+import sys
+
+from groups import group_lists
+
+# Copyright (C) 2018 Ben McGinnes <[email protected]>
+#
+# 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 License for 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/>.
+
+print("""
+This script applies a local signature or certification to every key in a group.
+
+Usage: local-sign-group.py <group name> [signing keyid] [gnupg homedir]
+""")
+
+c = gpg.Context(armor=True)
+mkfpr = None
+defkey_fpr = None
+enckey_fpr = None
+to_certify = []
+
+if len(sys.argv) >= 4:
+    clique = sys.argv[1]
+    sigkey = sys.argv[2]
+    homedir = sys.argv[3]
+elif len(sys.argv) == 3:
+    clique = sys.argv[1]
+    sigkey = sys.argv[2]
+    homedir = input("Enter the GPG configuration directory path (optional): ")
+elif len(sys.argv) == 2:
+    clique = sys.argv[1]
+    sigkey = input("Enter the key ID to sign with (conditionally optional): ")
+    homedir = input("Enter the GPG configuration directory path (optional): ")
+else:
+    clique = input("Enter the group matching the key(s) to locally sign: ")
+    sigkey = input("Enter the key ID to sign with (conditionally optional): ")
+    homedir = input("Enter the GPG configuration directory path (optional): ")
+
+if len(homedir) == 0:
+    homedir = None
+elif homedir.startswith("~"):
+    userdir = os.path.expanduser(homedir)
+    if os.path.exists(userdir) is True:
+        homedir = os.path.realpath(userdir)
+    else:
+        homedir = None
+else:
+    homedir = os.path.realpath(homedir)
+
+if homedir is not None and os.path.exists(homedir) is False:
+    homedir = None
+elif homedir is not None and os.path.exists(homedir) is True:
+    if os.path.isdir(homedir) is False:
+        homedir = None
+    else:
+        pass
+
+if homedir is not None:
+    c.home_dir = homedir
+else:
+    pass
+
+if len(sigkey) == 0:
+    sigkey = None
+else:
+    pass
+
+if sys.platform == "win32":
+    gpgconfcmd = "gpgconf.exe --list-options gpg"
+else:
+    gpgconfcmd = "gpgconf --list-options gpg"
+
+try:
+    lines = subprocess.getoutput(gpgconfcmd).splitlines()
+except:
+    process = subprocess.Popen(gpgconfcmd.split(), stdout=subprocess.PIPE)
+    procom = process.communicate()
+    if sys.version_info[0] == 2:
+        lines = procom[0].splitlines()
+    else:
+        lines = procom[0].decode().splitlines()
+
+for i in range(len(lines)):
+    if lines[i].startswith("default-key") is True:
+        dline = lines[i]
+    elif lines[i].startswith("encrypt-to") is True:
+        eline = lines[i]
+    else:
+        pass
+
+defkey_fpr = dline.split(":")[-1].replace('"', '').split(',')[0].upper()
+enckey_fpr = eline.split(":")[-1].replace('"', '').split(',')[0].upper()
+
+if sigkey is not None:
+    mykey = c.keylist(pattern=sigkey)
+    mk = list(mykey)
+    mkfpr = mk[0].fpr.upper()
+else:
+    pass
+
+for group in group_lists:
+    if group[0] == clique:
+        for logrus in group[1]:
+            khole = c.keylist(pattern=logrus)
+            k = list(khole)
+            to_certify.append(k[0].fpr.upper())
+    else:
+        pass
+
+if mkfpr is not None:
+    if to_certify.count(mkfpr) > 0:
+        for n in range(to_certify.count(mkfpr)):
+            to_certify.remove(mkfpr)
+    else:
+        pass
+else:
+    pass
+
+if defkey_fpr is not None:
+    if to_certify.count(defkey_fpr) > 0:
+        for n in range(to_certify.count(defkey_fpr)):
+            to_certify.remove(defkey_fpr)
+    else:
+        pass
+else:
+    pass
+
+if enckey_fpr is not None:
+    if to_certify.count(enckey_fpr) > 0:
+        for n in range(to_certify.count(enckey_fpr)):
+            to_certify.remove(enckey_fpr)
+    else:
+        pass
+else:
+    pass
+
+for fpr in to_certify:
+    key = c.get_key(fpr)
+    c.key_sign(key, uids=None, expires_in=False, local=True)