cert_audit: Initial script for auditing expiry date
We introduce the script to audit the expiry date of X509 files
(i.e. crt/crl/csr files) in tests/data_files/ folder.
This commit add basic classes and the framework for auditing
and "-a" option to list all valid crt/crl/csr files it found.
Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
diff --git a/tests/scripts/audit-validity-dates.py b/tests/scripts/audit-validity-dates.py
new file mode 100755
index 0000000..67d4096
--- /dev/null
+++ b/tests/scripts/audit-validity-dates.py
@@ -0,0 +1,282 @@
+#!/usr/bin/env python3
+#
+# copyright the mbed tls contributors
+# spdx-license-identifier: apache-2.0
+#
+# 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.
+
+"""Audit validity date of X509 crt/crl/csr
+
+This script is used to audit the validity date of crt/crl/csr used for testing.
+The files are in tests/data_files/ while some data are in test suites data in
+tests/suites/*.data files.
+"""
+
+import os
+import sys
+import re
+import typing
+import types
+import argparse
+import datetime
+from enum import Enum
+
+from cryptography import x509
+
+class DataType(Enum):
+ CRT = 1 # Certificate
+ CRL = 2 # Certificate Revocation List
+ CSR = 3 # Certificate Signing Request
+
+class DataFormat(Enum):
+ PEM = 1 # Privacy-Enhanced Mail
+ DER = 2 # Distinguished Encoding Rules
+
+class AuditData:
+ """Store file, type and expiration date for audit."""
+ #pylint: disable=too-few-public-methods
+ def __init__(self, data_type: DataType):
+ self.data_type = data_type
+ self.filename = ""
+ self.not_valid_after: datetime.datetime
+ self.not_valid_before: datetime.datetime
+
+ def fill_validity_duration(self, x509_obj):
+ """Fill expiration_date field from a x509 object"""
+ # Certificate expires after "not_valid_after"
+ # Certificate is invalid before "not_valid_before"
+ if self.data_type == DataType.CRT:
+ self.not_valid_after = x509_obj.not_valid_after
+ self.not_valid_before = x509_obj.not_valid_before
+ # CertificateRevocationList expires after "next_update"
+ # CertificateRevocationList is invalid before "last_update"
+ elif self.data_type == DataType.CRL:
+ self.not_valid_after = x509_obj.next_update
+ self.not_valid_before = x509_obj.last_update
+ # CertificateSigningRequest is always valid.
+ elif self.data_type == DataType.CSR:
+ self.not_valid_after = datetime.datetime.max
+ self.not_valid_before = datetime.datetime.min
+ else:
+ raise ValueError("Unsupported file_type: {}".format(self.data_type))
+
+class X509Parser():
+ """A parser class to parse crt/crl/csr file or data in PEM/DER format."""
+ PEM_REGEX = br'-{5}BEGIN (?P<type>.*?)-{5}\n(?P<data>.*?)-{5}END (?P=type)-{5}\n'
+ PEM_TAG_REGEX = br'-{5}BEGIN (?P<type>.*?)-{5}\n'
+ PEM_TAGS = {
+ DataType.CRT: 'CERTIFICATE',
+ DataType.CRL: 'X509 CRL',
+ DataType.CSR: 'CERTIFICATE REQUEST'
+ }
+
+ def __init__(self, backends: dict):
+ self.backends = backends
+ self.__generate_parsers()
+
+ def __generate_parser(self, data_type: DataType):
+ """Parser generator for a specific DataType"""
+ tag = self.PEM_TAGS[data_type]
+ pem_loader = self.backends[data_type][DataFormat.PEM]
+ der_loader = self.backends[data_type][DataFormat.DER]
+ def wrapper(data: bytes):
+ pem_type = X509Parser.pem_data_type(data)
+ # It is in PEM format with target tag
+ if pem_type == tag:
+ return pem_loader(data)
+ # It is in PEM format without target tag
+ if pem_type:
+ return None
+ # It might be in DER format
+ try:
+ result = der_loader(data)
+ except ValueError:
+ result = None
+ return result
+ wrapper.__name__ = "{}.parser[{}]".format(type(self).__name__, tag)
+ return wrapper
+
+ def __generate_parsers(self):
+ """Generate parsers for all support DataType"""
+ self.parsers = {}
+ for data_type, _ in self.PEM_TAGS.items():
+ self.parsers[data_type] = self.__generate_parser(data_type)
+
+ def __getitem__(self, item):
+ return self.parsers[item]
+
+ @staticmethod
+ def pem_data_type(data: bytes) -> str:
+ """Get the tag from the data in PEM format
+
+ :param data: data to be checked in binary mode.
+ :return: PEM tag or "" when no tag detected.
+ """
+ m = re.search(X509Parser.PEM_TAG_REGEX, data)
+ if m is not None:
+ return m.group('type').decode('UTF-8')
+ else:
+ return ""
+
+class Auditor:
+ """A base class for audit."""
+ def __init__(self, verbose):
+ self.verbose = verbose
+ self.default_files = []
+ self.audit_data = []
+ self.parser = X509Parser({
+ DataType.CRT: {
+ DataFormat.PEM: x509.load_pem_x509_certificate,
+ DataFormat.DER: x509.load_der_x509_certificate
+ },
+ DataType.CRL: {
+ DataFormat.PEM: x509.load_pem_x509_crl,
+ DataFormat.DER: x509.load_der_x509_crl
+ },
+ DataType.CSR: {
+ DataFormat.PEM: x509.load_pem_x509_csr,
+ DataFormat.DER: x509.load_der_x509_csr
+ },
+ })
+
+ def error(self, *args):
+ #pylint: disable=no-self-use
+ print("Error: ", *args, file=sys.stderr)
+
+ def warn(self, *args):
+ if self.verbose:
+ print("Warn: ", *args, file=sys.stderr)
+
+ def parse_file(self, filename: str) -> typing.List[AuditData]:
+ """
+ Parse a list of AuditData from file.
+
+ :param filename: name of the file to parse.
+ :return list of AuditData parsed from the file.
+ """
+ with open(filename, 'rb') as f:
+ data = f.read()
+ result_list = []
+ result = self.parse_bytes(data)
+ if result is not None:
+ result.filename = filename
+ result_list.append(result)
+ return result_list
+
+ def parse_bytes(self, data: bytes):
+ """Parse AuditData from bytes."""
+ for data_type in list(DataType):
+ try:
+ result = self.parser[data_type](data)
+ except ValueError as val_error:
+ result = None
+ self.warn(val_error)
+ if result is not None:
+ audit_data = AuditData(data_type)
+ audit_data.fill_validity_duration(result)
+ return audit_data
+ return None
+
+ def walk_all(self, file_list):
+ """
+ Iterate over all the files in the list and get audit data.
+ """
+ if not file_list:
+ file_list = self.default_files
+ for filename in file_list:
+ data_list = self.parse_file(filename)
+ self.audit_data.extend(data_list)
+
+ def for_each(self, do, *args, **kwargs):
+ """
+ Sort the audit data and iterate over them.
+ """
+ if not isinstance(do, types.FunctionType):
+ return
+ for d in self.audit_data:
+ do(d, *args, **kwargs)
+
+ @staticmethod
+ def find_test_dir():
+ """Get the relative path for the MbedTLS test directory."""
+ if os.path.isdir('tests'):
+ tests_dir = 'tests'
+ elif os.path.isdir('suites'):
+ tests_dir = '.'
+ elif os.path.isdir('../suites'):
+ tests_dir = '..'
+ else:
+ raise Exception("Mbed TLS source tree not found")
+ return tests_dir
+
+class TestDataAuditor(Auditor):
+ """Class for auditing files in tests/data_files/"""
+ def __init__(self, verbose):
+ super().__init__(verbose)
+ self.default_files = self.collect_default_files()
+
+ def collect_default_files(self):
+ """collect all files in tests/data_files/"""
+ test_dir = self.find_test_dir()
+ test_data_folder = os.path.join(test_dir, 'data_files')
+ data_files = []
+ for (dir_path, _, file_names) in os.walk(test_data_folder):
+ data_files.extend(os.path.join(dir_path, file_name)
+ for file_name in file_names)
+ return data_files
+
+
+def list_all(audit_data: AuditData):
+ print("{}\t{}\t{}\t{}".format(
+ audit_data.not_valid_before.isoformat(timespec='seconds'),
+ audit_data.not_valid_after.isoformat(timespec='seconds'),
+ audit_data.data_type.name,
+ audit_data.filename))
+
+def main():
+ """
+ Perform argument parsing.
+ """
+ parser = argparse.ArgumentParser(
+ description='Audit script for X509 crt/crl/csr files.'
+ )
+
+ parser.add_argument('-a', '--all',
+ action='store_true',
+ help='list the information of all files')
+ parser.add_argument('-v', '--verbose',
+ action='store_true', dest='verbose',
+ help='Show warnings')
+ parser.add_argument('-f', '--file', dest='file',
+ help='file to audit (Debug only)',
+ metavar='FILE')
+
+ args = parser.parse_args()
+
+ # start main routine
+ td_auditor = TestDataAuditor(args.verbose)
+
+ if args.file:
+ data_files = [args.file]
+ else:
+ data_files = td_auditor.default_files
+
+ td_auditor.walk_all(data_files)
+
+ if args.all:
+ td_auditor.for_each(list_all)
+
+ print("\nDone!\n")
+
+if __name__ == "__main__":
+ main()