1 files changed, 253 insertions, 0 deletions
diff --git a/script/fetch-ocsp-response b/script/fetch-ocsp-response
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+++ b/script/fetch-ocsp-response
@@ -0,0 +1,253 @@
+#!/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 exited 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 1.0.') 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)