gpg-email-helper/gpg-email-helper.py

import gpg
import hkp4py
import os
import sys

XDG_DATA_HOME = os.getenv('XDG_DATA_HOME')
HOME = os.path.expanduser('~')
if XDG_DATA_HOME == None:
    XDG_DATA_HOME = f'{HOME}/.local/share'

filename = sys.argv[-1]
email = ''.join(open(filename, 'rt').readlines())

if 'gpg-email-helper' not in os.listdir(f'{XDG_DATA_HOME}'):
    os.mkdir(f'{XDG_DATA_HOME}/gpg-email-helper')

with open(f'{XDG_DATA_HOME}/gpg-email-helper/log', 'a') as log:
    log.write(f'\n\nRunning on {filename}\n')

    # Untested as I'm missing a real email with this done properly - is this even supported by anything?
    if email.rfind('-----BEGIN PGP PUBLIC KEY BLOCK-----') != -1 and email.rfind('-----END PGP PUBLIC KEY BLOCK-----') != -1:
        public_key = email[email.rfind(
            '-----BEGIN PGP PUBLIC KEY BLOCK-----'):email.rfind('-----END PGP PUBLIC KEY BLOCK-----')+35]
        public_key = public_key.replace('=3D', '=') # quoted-printable attachments have the equals sign escaped as =3D apparently
        log.write(
            f'Attempted to import key from email: {gpg.Context(armor=True).key_import(public_key.encode())}\n')

    elif (
        email.rfind('-----BEGIN PGP SIGNATURE-----') != -1
        and email.rfind('-----END PGP SIGNATURE-----') != -1
    ):
        signature = email[
            email.rfind('-----BEGIN PGP SIGNATURE-----'): email.rfind(
                '-----END PGP SIGNATURE-----'
            )+27
        ]

        try:
            # Needed to skip geting the key if it already exists.
            gpg.Context().verify(signature.encode())
        except gpg.errors.BadSignatures as e:
            if 'No public key' in str(e):
                fingerprint = str(e)[: str(e).find(':')]
                log.write(
                    f'{fingerprint} not found, gonna try to find it on a keyserver...\n'
                )
                keyservers = [
                    'keyserver.ubuntu.com',
                    'pgpkeys.eu',
                    'pgp.cyberbits.eu',
                    'pgp.flexyz.com',
                    'sks.pgpkeys.eu',
                    'fi.pgpkeys.eu',
                    'keys.nicemail.eu',
                    'pubkeys.intevation.de',
                    'pgp.surf.nl',
                    'sks.pod03.togsvcs.com',
                    'sks.ewr1.newconews.org',
                    'sks.pod02.fleetstreetops.com',
                    'sks.pod01.fleetstreetops.com',
                    'pgp.net.nz',
                    'zuul.rediris.es',
                    'pgp.gnd.pw',
                    'openpgp.circl.lu',
                    'keywin.trifence.ch',
                    'data.pgp.gnd.pw',
                    'sks.infcs.de',
                    'keyserver.escomposlinux.org',
                    'keyserver.cert.or.id',
                    'keyserver1.computer42.org',
                    'keyserver2.computer42.org',
                    'keyserver.spline.inf.fu-berlin.de',
                    'key-server.org',
                    'pgp.id',
                    'sks.ygrek.org',
                    # 'pgp.mit.edu' # still in operation but very unreliable
                ]

                for server in keyservers:
                    log.write(f'{server}: ')
                    try:
                        pubkey = hkp4py.KeyServer(
                            # This isn't perfect, it's a loose search
                            # for example searching for 7C79FCBB8372E5DE5B17E09A90D4B9641E092971 on keyserver.ubuntu.com returns the wrong key. But it works 99% of the time.
                            f'hkp://{server}').search(fingerprint)
                        if pubkey != None:
                            log.write(f'{pubkey}\n')
                            gpg.Context().key_import(pubkey)
                            break
                        else:
                            log.write('None\n')
                    except Exception as e:
                        log.write(f'[ERROR] {e}\n\n')
        except Exception as e:
            log.write(f'[ERROR] {e}\n\n')