Added script to generate a basic RevocationSet from TestNet or MainNet (#30837)

* Added script to generate a basic RevocationSet from TestNet or MainNet

* Updated the script to generate a basic RevocationSet from TestNet or MainNet

* Updated the script to generate a basic RevocationSet from TestNet or MainNet

* Addressed generate-revocation-set.py review comments

* Added comments to capture the follow-up work in the generate-revocation-set.py file.
diff --git a/credentials/generate-revocation-set.py b/credentials/generate-revocation-set.py
new file mode 100644
index 0000000..534edc1
--- /dev/null
+++ b/credentials/generate-revocation-set.py
@@ -0,0 +1,248 @@
+#!/usr/bin/python
+
+#
+# Copyright (c) 2023 Project CHIP Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Generates a basic RevocationSet from TestNet
+# Usage:
+#     python ./credentials/generate-revocation-set.py --help
+
+import base64
+import json
+import subprocess
+import sys
+from enum import Enum
+
+import click
+import requests
+from click_option_group import RequiredMutuallyExclusiveOptionGroup, optgroup
+from cryptography import x509
+
+
+class RevocationType(Enum):
+    CRL = 1
+
+
+OID_VENDOR_ID = x509.ObjectIdentifier("1.3.6.1.4.1.37244.2.1")
+OID_PRODUCT_ID = x509.ObjectIdentifier("1.3.6.1.4.1.37244.2.2")
+
+PRODUCTION_NODE_URL = "https://on.dcl.csa-iot.org:26657"
+PRODUCTION_NODE_URL_REST = "https://on.dcl.csa-iot.org"
+TEST_NODE_URL_REST = "https://on.test-net.dcl.csa-iot.org"
+
+
+def use_dcld(dcld, production, cmdlist):
+    return [dcld] + cmdlist + (['--node', PRODUCTION_NODE_URL] if production else [])
+
+
+def extract_single_integer_attribute(subject, oid):
+    attribute_list = subject.get_attributes_for_oid(oid)
+
+    if len(attribute_list) == 1:
+        if attribute_list[0].value.isdigit():
+            return int(attribute_list[0].value)
+
+    return None
+
+
+@click.command()
+@click.help_option('-h', '--help')
+@optgroup.group('Input data sources', cls=RequiredMutuallyExclusiveOptionGroup)
+@optgroup.option('--use-main-net-dcld', type=str, default='', metavar='PATH', help="Location of `dcld` binary, to use `dcld` for mirroring MainNet.")
+@optgroup.option('--use-test-net-dcld', type=str, default='', metavar='PATH', help="Location of `dcld` binary, to use `dcld` for mirroring TestNet.")
+@optgroup.option('--use-main-net-http', is_flag=True, type=str, help="Use RESTful API with HTTPS against public MainNet observer.")
+@optgroup.option('--use-test-net-http', is_flag=True, type=str, help="Use RESTful API with HTTPS against public TestNet observer.")
+@optgroup.group('Optional arguments')
+@optgroup.option('--output', default='sample_revocation_set_list.json', type=str, metavar='FILEPATH', help="Output filename (default: sample_revocation_set_list.json)")
+def main(use_main_net_dcld, use_test_net_dcld, use_main_net_http, use_test_net_http, output):
+    """DCL PAA mirroring tools"""
+
+    production = False
+    dcld = use_test_net_dcld
+
+    if len(use_main_net_dcld) > 0:
+        dcld = use_main_net_dcld
+        production = True
+
+    use_rest = use_main_net_http or use_test_net_http
+    if use_main_net_http:
+        production = True
+
+    rest_node_url = PRODUCTION_NODE_URL_REST if production else TEST_NODE_URL_REST
+
+    # TODO: Extract this to a helper function
+    if use_rest:
+        revocation_point_list = requests.get(f"{rest_node_url}/dcl/pki/revocation-points").json()["PkiRevocationDistributionPoint"]
+    else:
+        cmdlist = ['config', 'output', 'json']
+        subprocess.Popen([dcld] + cmdlist)
+
+        cmdlist = ['query', 'pki', 'all-revocation-points']
+
+        cmdpipe = subprocess.Popen(use_dcld(dcld, production, cmdlist), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
+        revocation_point_list = json.loads(cmdpipe.stdout.read())["PkiRevocationDistributionPoint"]
+
+    revocation_set = []
+
+    for revocation_point in revocation_point_list:
+        # 1. Validate Revocation Type
+        if revocation_point["revocationType"] != RevocationType.CRL:
+            continue
+
+        # 2. Parse the certificate
+        crl_signer_certificate = x509.load_pem_x509_certificate(revocation_point["crlSignerCertificate"])
+
+        vid = revocation_point["vid"]
+        pid = revocation_point["pid"]
+        is_paa = revocation_point["isPAA"]
+
+        # 3. && 4. Validate VID/PID
+        # TODO: Need to support alternate representation of VID/PID (see spec "6.2.2.2. Encoding of Vendor ID and Product ID in subject and issuer fields")
+        crl_vid = extract_single_integer_attribute(crl_signer_certificate.subject, OID_VENDOR_ID)
+        crl_pid = extract_single_integer_attribute(crl_signer_certificate.subject, OID_PRODUCT_ID)
+
+        if is_paa:
+            if crl_vid is not None:
+                if vid != crl_vid:
+                    # TODO: Need to log all situations where a continue is called
+                    continue
+        else:
+            if crl_vid is None or vid != crl_vid:
+                continue
+            if crl_pid is not None:
+                if pid != crl_pid:
+                    continue
+
+        # 5. Validate the certification path containing CRLSignerCertificate.
+        crl_signer_issuer_name = base64.b64encode(crl_signer_certificate.issuer.public_bytes()).decode('utf-8')
+
+        crl_signer_authority_key_id = crl_signer_certificate.extensions.get_extension_for_oid(
+            x509.OID_AUTHORITY_KEY_IDENTIFIER).value.key_identifier
+
+        paa_certificate = None
+
+        # TODO: Extract this to a helper function
+        if use_rest:
+            response = requests.get(
+                f"{rest_node_url}/dcl/pki/certificates/{crl_signer_issuer_name}/{crl_signer_authority_key_id}").json()["approvedCertificates"]["certs"][0]
+            paa_certificate = response["pemCert"]
+        else:
+            cmdlist = ['query', 'pki', 'x509-cert', '-u', crl_signer_issuer_name, '-k', crl_signer_authority_key_id]
+            cmdpipe = subprocess.Popen(use_dcld(dcld, production, cmdlist), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            paa_certificate = json.loads(cmdpipe.stdout.read())["approvedCertificates"]["certs"][0]["pemCert"]
+
+        if paa_certificate is None:
+            continue
+
+        paa_certificate_object = x509.load_pem_x509_certificate(paa_certificate)
+
+        try:
+            crl_signer_certificate.verify_directly_issued_by(paa_certificate_object)
+        except Exception:
+            continue
+
+        # 6. Obtain the CRL
+        r = requests.get(revocation_point["dataURL"])
+        crl_file = x509.load_der_x509_crl(r.content)
+
+        # 7. Perform CRL File Validation
+        crl_authority_key_id = crl_file.extensions.get_extension_for_oid(x509.OID_AUTHORITY_KEY_IDENTIFIER).value.key_identifier
+        crl_signer_subject_key_id = crl_signer_certificate.extensions.get_extension_for_oid(
+            x509.OID_SUBJECT_KEY_IDENTIFIER).value.key_identifier
+        if crl_authority_key_id != crl_signer_subject_key_id:
+            continue
+
+        issuer_subject_key_id = ''.join('{:02X}'.format(x) for x in crl_authority_key_id)
+
+        same_issuer_points = None
+
+        # TODO: Extract this to a helper function
+        if use_rest:
+            response = requests.get(
+                f"{rest_node_url}/dcl/pki/revocation-points/{issuer_subject_key_id}").json()["pkiRevocationDistributionPointsByIssuerSubjectKeyID"]
+            same_issuer_points = response["points"]
+        else:
+            cmdlist = ['query', 'pki', 'revocation-points', '--issuer-subject-key-id', issuer_subject_key_id]
+            cmdpipe = subprocess.Popen(use_dcld(dcld, production, cmdlist), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            same_issuer_points = json.loads(cmdpipe.stdout.read())[
+                "pkiRevocationDistributionPointsByIssuerSubjectKeyID"]["points"]
+
+        matching_entries = False
+        for same_issuer_point in same_issuer_points:
+            if same_issuer_point["vid"] == vid:
+                matching_entries = True
+                break
+
+        if matching_entries:
+            try:
+                issuing_distribution_point = crl_file.extensions.get_extension_for_oid(
+                    x509.OID_ISSUING_DISTRIBUTION_POINT).value
+            except Exception:
+                continue
+
+            uri_list = issuing_distribution_point.full_name
+            if len(uri_list) == 1 and isinstance(uri_list[0], x509.UniformResourceIdentifier):
+                if uri_list[0].value != revocation_point["dataURL"]:
+                    continue
+            else:
+                continue
+
+        # 9. Assign CRL File Issuer
+        certificate_authority_name = base64.b64encode(crl_file.issuer.public_bytes()).decode('utf-8')
+
+        serialnumber_list = []
+        # 10. Iterate through the Revoked Certificates List
+        for revoked_cert in crl_file:
+            try:
+                revoked_cert_issuer = revoked_cert.extensions.get_extension_for_oid(
+                    x509.CRLEntryExtensionOID.CERTIFICATE_ISSUER).value.get_values_for_type(x509.DirectoryName).value
+
+                if revoked_cert_issuer is not None:
+                    if revoked_cert_issuer != certificate_authority_name:
+                        continue
+            except Exception:
+                pass
+
+            # b.
+            try:
+                revoked_cert_authority_key_id = revoked_cert.extensions.get_extension_for_oid(
+                    x509.OID_AUTHORITY_KEY_IDENTIFIER).value.key_identifier
+
+                if revoked_cert_authority_key_id is None or revoked_cert_authority_key_id != crl_signer_subject_key_id:
+                    continue
+            except Exception:
+                continue
+
+            # c. and d.
+            serialnumber_list.append(bytes(str('{:02X}'.format(revoked_cert.serial_number)), 'utf-8').decode('utf-8'))
+
+        issuer_name = base64.b64encode(crl_file.issuer.public_bytes()).decode('utf-8')
+
+        revocation_set.append({"type": "revocation_set",
+                               "issuer_subject_key_id": issuer_subject_key_id,
+                               "issuer_name": issuer_name,
+                               "revoked_serial_numbers": serialnumber_list})
+
+    with open(output, 'w+') as outfile:
+        json.dump(revocation_set, outfile, indent=4)
+
+
+if __name__ == "__main__":
+    if len(sys.argv) == 1:
+        main.main(['--help'])
+    else:
+        main()