third_party_nghttp2/script/fetch-ocsp-response
Tatsuhiro Tsujikawa a4156cded3 fetch-ocsp-response: Handle spurious openssl exist status 0
With OpenSSL <= 1.0.1, openssl ocsp command still returns exit code 0,
even if verification was failed.  If that happens certain string is
emitted in stderr, so check that string and if exists, treat it as
error.  This issue was fixed in OpenSSL 1.0.2.

At least OpenSSL 1.0.2, openssl ocsp command still returns exit code
0, even if responder returned non-successful status code (e.g.,
trylater(3)).  We are not sure this is intentional or not.  To handle
this, we again check certain error string in stdout, and if it is
found, treat it as error.
2015-08-21 23:28:45 +09:00

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)