chromium/net/data/verify_certificate_chain_unittest/policies-inhibit-mapping-by-root-ok/generate-chains.py

#!/usr/bin/env python3
# Copyright 2023 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Certificate chain with inhibitPolicyMapping=1 on the root, and an
intermediate that uses policy mappings. Should pass, since policy mapping will
be allowed on the intermediate."""

import sys
sys.path += ['../..']

import gencerts

# Self-signed root certificate.
root = gencerts.create_self_signed_root_certificate('Root')
root.get_extensions().set_property('policyConstraints',
                                   'critical,inhibitPolicyMapping:1')

# Intermediate certificate.
intermediate = gencerts.create_intermediate_certificate('Intermediate', root)
intermediate.get_extensions().set_property('policyConstraints',
                                           'critical,requireExplicitPolicy:0')

intermediate.get_extensions().set_property('certificatePolicies',
                                           'critical,1.2.3.4')

intermediate.get_extensions().set_property('policyMappings',
                                           'critical,@policy_mappings')
policy_mappings = intermediate.config.get_section('policy_mappings')
policy_mappings.set_property('1.2.3.4', '1.2.3.5')

# Target certificate.
target = gencerts.create_end_entity_certificate('Target', intermediate)
target.get_extensions().set_property('certificatePolicies', 'critical,1.2.3.5')

chain = [target, intermediate, root]
gencerts.write_chain(__doc__, chain, 'chain.pem')