nghttp2/script/fetch-ocsp-response

254 lines
8.8 KiB
Python
Executable File

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# nghttp2 - HTTP/2 C Library
# Copyright (c) 2015 Tatsuhiro Tsujikawa
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
# This program was translated from the program originally developed by
# h2o project (https://github.com/h2o/h2o), written in Perl. It had
# the following copyright notice:
# Copyright (c) 2015 DeNA Co., Ltd.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.
from __future__ import unicode_literals
import argparse
import io
import os
import os.path
import re
import shutil
import subprocess
import sys
import tempfile
# make this program work for both Python 3 and Python 2.
try:
from urllib.parse import urlparse
stdout_bwrite = sys.stdout.buffer.write
except ImportError:
from urlparse import urlparse
stdout_bwrite = sys.stdout.write
def die(msg):
sys.stderr.write(msg)
sys.stderr.write('\n')
sys.exit(255)
def tempfail(msg):
sys.stderr.write(msg)
sys.stderr.write('\n')
sys.exit(os.EX_TEMPFAIL)
def run_openssl(args, allow_tempfail=False):
buf = io.BytesIO()
try:
p = subprocess.Popen(args, stdout=subprocess.PIPE)
except Exception as e:
die('failed to invoke {}:{}'.format(args, e))
try:
while True:
data = p.stdout.read()
if len(data) == 0:
break
buf.write(data)
if p.wait() != 0:
raise Exception('nonzero return code {}'.format(p.returncode))
return buf.getvalue()
except Exception as e:
msg = 'OpenSSL exitted abnormally: {}:{}'.format(args, e)
tempfail(msg) if allow_tempfail else die(msg)
def read_file(path):
with open(path, 'rb') as f:
return f.read()
def write_file(path, data):
with open(path, 'wb') as f:
f.write(data)
def detect_openssl_version(cmd):
return run_openssl([cmd, 'version']).decode('utf-8').strip()
def extract_ocsp_uri(cmd, cert_fn):
# obtain ocsp uri
ocsp_uri = run_openssl(
[cmd, 'x509', '-in', cert_fn, '-noout',
'-ocsp_uri']).decode('utf-8').strip()
if not re.match(r'^https?://', ocsp_uri):
die('failed to extract ocsp URI from {}'.format(cert_fn))
return ocsp_uri
def save_issuer_certificate(issuer_fn, cert_fn):
# save issuer certificate
chain = read_file(cert_fn).decode('utf-8')
m = re.match(
r'.*?-----END CERTIFICATE-----.*?(-----BEGIN CERTIFICATE-----.*?-----END CERTIFICATE-----)',
chain, re.DOTALL)
if not m:
die('--issuer option was not used, and failed to extract issuer certificate from the certificate')
write_file(issuer_fn, (m.group(1) + '\n').encode('utf-8'))
def send_and_receive_ocsp(respder_fn, cmd, cert_fn, issuer_fn, ocsp_uri,
ocsp_host, openssl_version):
# obtain response (without verification)
sys.stderr.write('sending OCSP request to {}\n'.format(ocsp_uri))
args = [
cmd, 'ocsp', '-issuer', issuer_fn, '-cert', cert_fn, '-url', ocsp_uri,
'-noverify', '-respout', respder_fn
]
ver = openssl_version.lower()
if ver.startswith('openssl 1.') or ver.startswith('libressl '):
args.extend(['-header', 'Host', ocsp_host])
resp = run_openssl(args, allow_tempfail=True)
return resp.decode('utf-8')
def verify_response(cmd, tempdir, issuer_fn, respder_fn):
# verify the response
sys.stderr.write('verifying the response signature\n')
verify_fn = os.path.join(tempdir, 'verify.out')
# try from exotic options
allextra = [
# for comodo
['-VAfile', issuer_fn],
# these options are only available in OpenSSL >= 1.0.2
['-partial_chain', '-trusted_first', '-CAfile', issuer_fn],
# for OpenSSL <= 1.0.1
['-CAfile', issuer_fn],
]
for extra in allextra:
with open(verify_fn, 'w+b') as f:
args = [cmd, 'ocsp', '-respin', respder_fn]
args.extend(extra)
p = subprocess.Popen(args, stdout=f, stderr=f)
if p.wait() == 0:
# OpenSSL <= 1.0.1, openssl ocsp still returns exit
# code 0 even if verification was failed. So check
# the error message in stderr output.
f.seek(0)
if f.read().decode('utf-8').find(
'Response Verify Failure') != -1:
continue
sys.stderr.write('verify OK (used: {})\n'.format(extra))
return True
sys.stderr.write(read_file(verify_fn).decode('utf-8'))
return False
def fetch_ocsp_response(cmd, cert_fn, tempdir, issuer_fn=None):
openssl_version = detect_openssl_version(cmd)
sys.stderr.write(
'fetch-ocsp-response (using {})\n'.format(openssl_version))
ocsp_uri = extract_ocsp_uri(cmd, cert_fn)
ocsp_host = urlparse(ocsp_uri).netloc
if not issuer_fn:
issuer_fn = os.path.join(tempdir, 'issuer.crt')
save_issuer_certificate(issuer_fn, cert_fn)
respder_fn = os.path.join(tempdir, 'resp.der')
resp = send_and_receive_ocsp(
respder_fn, cmd, cert_fn, issuer_fn, ocsp_uri, ocsp_host,
openssl_version)
sys.stderr.write('{}\n'.format(resp))
# OpenSSL 1.0.2 still returns exit code 0 even if ocsp responder
# returned error status (e.g., trylater(3))
if resp.find('Responder Error:') != -1:
raise Exception('responder returned error')
if not verify_response(cmd, tempdir, issuer_fn, respder_fn):
tempfail('failed to verify the response')
# success
res = read_file(respder_fn)
stdout_bwrite(res)
if __name__ == '__main__':
parser = argparse.ArgumentParser(
description=
'''The command issues an OCSP request for given server certificate, verifies the response and prints the resulting DER.''',
epilog=
'''The command exits 0 if successful, or 75 (EX_TEMPFAIL) on temporary error. Other exit codes may be returned in case of hard errors.''')
parser.add_argument(
'--issuer',
metavar='FILE',
help=
'issuer certificate (if omitted, is extracted from the certificate chain)')
parser.add_argument('--openssl',
metavar='CMD',
help='openssl command to use (default: "openssl")',
default='openssl')
parser.add_argument('certificate',
help='path to certificate file to validate')
args = parser.parse_args()
tempdir = None
try:
# Python3.2 has tempfile.TemporaryDirectory, which has nice
# feature to delete its tree by cleanup() function. We have
# to support Python2.7, so we have to do this manually.
tempdir = tempfile.mkdtemp()
fetch_ocsp_response(args.openssl, args.certificate, tempdir,
args.issuer)
finally:
if tempdir:
shutil.rmtree(tempdir)