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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2020 by the Linux Foundation
#
import sys
import os
import re
import email
import email.utils
import email.message
import smtplib
import mailbox
import b4
logger = b4.logger
def create_attestation(cmdargs):
attlines = list()
subject = 'Patch attestation'
for patchfile in cmdargs.patchfile:
with open(patchfile, 'r', encoding='utf-8') as fh:
content = fh.read()
if content.find('From') != 0:
logger.info('SKIP | %s', os.path.basename(patchfile))
continue
msg = email.message_from_string(content)
lmsg = b4.LoreMessage(msg)
lmsg.load_hashes()
att = lmsg.attestation
if att is None:
logger.info('SKIP | %s', os.path.basename(patchfile))
# See if it's a cover letter
if lmsg.counters_inferred or lmsg.counter > 0:
# No
continue
newprefs = list()
for prefix in lmsg.lsubject.prefixes:
if prefix.lower() == 'patch':
newprefs.append('PSIGN')
elif prefix == '%s/%s' % (lmsg.counter, lmsg.expected):
newprefs.append('X/%s' % lmsg.expected)
else:
newprefs.append(prefix)
subject = '[%s] %s' % (' '.join(newprefs), lmsg.subject)
continue
logger.info('HASH | %s', os.path.basename(patchfile))
attlines.append('%s:' % att.attid)
attlines.append(' i: %s' % att.i)
attlines.append(' m: %s' % att.m)
attlines.append(' p: %s' % att.p)
payload = '\n'.join(attlines)
usercfg = b4.get_user_config()
gpgargs = list()
if 'signingkey' in usercfg:
gpgargs += ['-u', usercfg['signingkey']]
gpgargs += ['--clearsign',
'--comment', 'att-fmt-ver: %s' % b4.ATTESTATION_FORMAT_VER,
'--comment', 'att-hash: sha256',
]
ecode, signed = b4.gpg_run_command(gpgargs, stdin=payload.encode('utf-8'))
if ecode > 0:
config = b4.get_main_config()
logger.critical('ERROR: Unable to sign using %s', config['gpgbin'])
sys.exit(1)
att_msg = email.message.EmailMessage()
att_msg.set_payload(signed.encode('utf-8'))
sender = cmdargs.sender
if '>' not in sender:
sender = '<%s>' % sender
att_msg['From'] = sender
att_msg['To'] = '<signatures@kernel.org>'
att_msg['Message-Id'] = email.utils.make_msgid(domain='kernel.org')
att_msg['Subject'] = subject
logger.info('---')
if not cmdargs.nosubmit:
# Try to deliver it via mail.kernel.org
try:
mailserver = smtplib.SMTP('mail.kernel.org', 587)
# identify ourselves to smtp gmail client
mailserver.ehlo()
# secure our email with tls encryption
mailserver.starttls()
# re-identify ourselves as an encrypted connection
mailserver.ehlo()
logger.info('Delivering via mail.kernel.org')
mailserver.sendmail('devnull@kernel.org', 'signatures@kernel.org', att_msg.as_string())
mailserver.quit()
sys.exit(0)
except Exception as ex:
logger.info('Could not deliver: %s', ex)
# Future iterations will also be able to submit this to a RESTful URL
# at git.kernel.org, in order not to depend on avaialbility of SMTP gateways
with open(cmdargs.output, 'wb') as fh:
fh.write(att_msg.as_bytes())
logger.info('Wrote %s', cmdargs.output)
logger.info('You can send it using:')
logger.info(' sendmail -oi signatures@kernel.org < %s', cmdargs.output)
logger.info(' mutt -H %s', cmdargs.output)
def verify_attestation(cmdargs):
config = b4.get_main_config()
if cmdargs.tofu:
config['attestation-trust-model'] = 'tofu'
exact_from_match = True
if cmdargs.ignorefrom:
exact_from_match = False
mbx = mailbox.mbox(cmdargs.mbox[0])
if cmdargs.attfile:
b4.LoreAttestationDocument.load_from_file(cmdargs.attfile)
eligible = list()
for msg in mbx:
lmsg = b4.LoreMessage(msg)
if lmsg.has_diff:
eligible.append(lmsg)
continue
# See if body has "att-fmt-ver
if re.search(r'^Comment: att-fmt-ver:', lmsg.body, re.I | re.M):
logger.debug('Found attestation message')
b4.LoreAttestationDocument.load_from_string(lmsg.msgid, lmsg.body)
logger.debug('SKIP | %s', msg['Subject'])
if not len(eligible):
logger.error('No patches found in %s', cmdargs.mbox[0])
sys.exit(1)
logger.info('---')
attrailers = set()
ecode = 1
if config['attestation-checkmarks'] == 'fancy':
attpass = b4.PASS_FANCY
attfail = b4.FAIL_FANCY
else:
attpass = b4.PASS_SIMPLE
attfail = b4.FAIL_SIMPLE
for lmsg in eligible:
attdoc = lmsg.get_attestation(lore_lookup=True, exact_from_match=exact_from_match)
if not attdoc:
logger.critical('%s %s', attfail, lmsg.full_subject)
if not cmdargs.nofast:
logger.critical('Aborting due to failure.')
ecode = 1
break
else:
ecode = 128
continue
if ecode != 128:
ecode = 0
logger.critical('%s %s', attpass, lmsg.full_subject)
attrailers.add(attdoc.lsig.attestor.get_trailer(lmsg.fromemail))
logger.critical('---')
if ecode > 0:
logger.critical('Attestation verification failed.')
errors = set()
for attdoc in b4.ATTESTATIONS:
errors.update(attdoc.errors)
if len(errors):
logger.critical('---')
logger.critical('The validation process reported the following errors:')
for error in errors:
logger.critical(' %s %s', attfail, error)
else:
logger.critical('All patches passed attestation:')
for attrailer in attrailers:
logger.critical(' %s %s', attpass, attrailer)
sys.exit(ecode)
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