Drop python2 support, lint fixes and a little refactoring

requirements.txt

@@ -0,0 +1,3 @@
+certifi==2024.2.2
+cryptography==42.0.5
+PyOpenSSL==24.1.0

sort_certificate.py

@@ -1,23 +1,27 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 '''
 Sort X509/private key material
 '''
 
-from __future__ import print_function
+import fileinput
-
 import logging
 import re
-import fileinput
+import sys
 from argparse import ArgumentParser
 from datetime import datetime
-from OpenSSL import crypto
+
-from cryptography.hazmat.primitives import serialization
 import certifi.core
+from cryptography.hazmat.primitives import serialization
+from OpenSSL import crypto
 
 VALID_FQDN_RE = r'^([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])'\
                 r'(\.([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]{0,61}'\
                 r'[a-zA-Z0-9]))*$'
 
+CERTIFICATE_RE = '(-{5}BEGIN CERTIFICATE-{5}.*?-{5}END CERTIFICATE-{5})'
+RSAPRIVKEY_RE = '(-{5}BEGIN RSA PRIVATE KEY-{5}.*?-{5}END RSA PRIVATE KEY-{5})'
+PRIVKEY_RE = '(-{5}BEGIN PRIVATE KEY-{5}.*?-{5}END PRIVATE KEY-{5})'
+
 CERTINFO_TEMPLATE = '''
 subject= /{subject}
 issuer= /{issuer}
@@ -30,56 +34,68 @@ ASN1TIME_FMT = str('%Y%m%d%H%M%SZ'.encode('utf8'))
 OPENSSLTIME_FMT = '%b %e %T %Y GMT'
 
 
-class PkDecorator(object):
+class PkDecorator:  # pylint: disable=too-few-public-methods
     '''
     Provide some information on the private key object
     '''
-    pk = None
+    p_key = None
 
-    def __init__(self, pk):
+    def __init__(self, p_key):
-        self.pk = pk
+        self.p_key = p_key
 
     def __str__(self):
         return "Private key"
 
 
-class PkDecoratorEC(PkDecorator):
+class PkDecoratorEC(PkDecorator):  # pylint: disable=too-few-public-methods
+    '''
+    PkDecorator that knowns about elliptic curves
+    '''
 
     def __str__(self):
-        pk_crypto = self.pk.to_cryptography_key()
+        pk_crypto = self.p_key.to_cryptography_key()
-        return "EC Private key curve %s (%d bits)" % (
+        return (f'EC Private key curve {pk_crypto.curve.name} '
-                pk_crypto.curve.name, pk_crypto.key_size)
+                f'({pk_crypto.key_size} bits)')
 
 
-class PkDecoratorRSA(PkDecorator):
+class PkDecoratorRSA(PkDecorator):  # pylint: disable=too-few-public-methods
+    '''
+    PkDecorator that knowns about RSA
+    '''
 
     def __str__(self):
-        pk_crypto = self.pk.to_cryptography_key()
+        pk_crypto = self.p_key.to_cryptography_key()
-        return "RSA Private key %d bits (exponent %d)" % (
+        return (f'RSA Private key {pk_crypto.key_size} bits '
-                pk_crypto.key_size,
+                f'(exponent {pk_crypto.private_numbers().public_numbers.e})')
-                pk_crypto.private_numbers().public_numbers.e)
 
 
-class PkDecoratorDSA(PkDecorator):
+class PkDecoratorDSA(PkDecorator):  # pylint: disable=too-few-public-methods
+    '''
+    PkDecorator that knowns about DSA
+    '''
 
     def __str__(self):
-        pk_crypto = self.pk.to_cryptography_key()
+        pk_crypto = self.p_key.to_cryptography_key()
-        return "DSA Private key %d bits" % pk_crypto.key_size
+        return f'DSA Private key {pk_crypto.key_size} bits'
 
 
-class PkDecoratorDH(PkDecorator):
+class PkDecoratorDH(PkDecorator):  # pylint: disable=too-few-public-methods
+    '''
+    PkDecorator that knowns about DH
+    '''
 
     def __str__(self):
-        pk_crypto = self.pk.to_cryptography_key()
+        pk_crypto = self.p_key.to_cryptography_key()
-        return "DH Private key %d bits" % pk_crypto.key_size
+        return f'DH Private key {pk_crypto.key_size} bits'
 
 
-class PkDecoratorFactory(object):
+class PkDecoratorFactory:  # pylint: disable=too-few-public-methods
     '''
     Provide some information on the private key object
     '''
 
-    def create(pk):
+    @staticmethod
+    def create(p_key):
         '''
         Create the appropriate decorater object
         '''
@@ -89,18 +105,16 @@ class PkDecoratorFactory(object):
                 crypto.TYPE_DSA: PkDecoratorDSA,
                 crypto.TYPE_RSA: PkDecoratorRSA,
         }
-        if pk.type() in decorators:
+        if p_key.type() in decorators:
-            return decorators[pk.type()](pk)
+            return decorators[p_key.type()](p_key)
-        else:
+        raise UnsupportedPkEncryption(
-            raise UnsupportedPkEncryption("Unsupported private key type %d"
+                'Unsupported private key type {p_key.type()}')
-                                          % pk.type())
 
 
 class UnsupportedPkEncryption(Exception):
     '''
     When we encounter unsupported encryption algorithms
     '''
-    pass
 
 
 class CertificateComponentException(Exception):
@@ -108,7 +122,6 @@ class CertificateComponentException(Exception):
     When something is not right with the whole cert+intermediates+private key
     bundle
     '''
-    pass
 
 
 def load_data(filenames):
@@ -167,7 +180,7 @@ def match_cert_privkey(cert, priv):
     '''
     Copied from https://stackoverflow.com/questions/19922790/how-to-check-for-python-the-key-associated-with-the-certificate-or-not # noqa pylint: disable=line-too-long
     and reworked
-    '''
+    ''' # noqa: E501
 
     return get_cert_pubkey(cert) == get_priv_pubkey(priv)
 
@@ -220,9 +233,9 @@ def order_x509(x509_objects, root_issuers):
         if next((x for x in x509_objects
                  if x.get_subject() != x.get_issuer()
                  and x.get_subject() == root_crt.get_subject()), None):
-            raise CertificateComponentException('Both present as intermediate '
+            raise CertificateComponentException(
-                                                'and root certificate: %s' %
+                    f'Both present as intermediate '
-                                                str(root_crt.get_subject()))
+                    f'and root certificate: {str(root_crt.get_subject())}')
     else:
         # Get intermediate cert signed by any root from bundle as anchor, and
         # make that our root
@@ -253,10 +266,9 @@ def order_x509(x509_objects, root_issuers):
             bundle.insert(0, x509_objects.pop(x509_objects.index(sibling[0])))
         else:
             # Lets complain
-            raise CertificateComponentException('Non matching certificates in '
+            raise CertificateComponentException(
-                                                'input:'
+                    f'Non matching certificates in '
-                                                ' No sibling found for %s'
+                    f'input: No sibling found for {bundle[0].get_subject()}')
-                                                % bundle[0].get_subject())
     return bundle
 
 
@@ -268,7 +280,7 @@ def load_root_issuers():
 
     mozrootbundle_location = certifi.core.where()
 
-    with open(mozrootbundle_location, 'r') as fname_fh:
+    with open(mozrootbundle_location, 'r', encoding='utf-8') as fname_fh:
         logging.info('Using %s for root ca bundle', mozrootbundle_location)
         data = fname_fh.read()
         matches = re.finditer(r'(-----BEGIN CERTIFICATE-----'
@@ -368,15 +380,10 @@ def handle_args():
     return parser.parse_args()
 
 
-def main():
+def setup_logging(args):
     '''
-    main program start and argument parsing
+    Set up logging
     '''
-
-    root_issuers = None
-
-    args = handle_args()
-
     if args.verbose or args.check:
         logging.basicConfig(level=logging.INFO)
     elif args.debug:
@@ -386,24 +393,30 @@ def main():
     else:
         logging.basicConfig(level=logging.WARNING)
 
+
+def main():
+    '''
+    main program start and argument parsing
+    '''
+
+    root_issuers = None
+
+    args = handle_args()
+
+    setup_logging(args)
+
     root_issuers = load_root_issuers()
 
     for fname, data in list(load_data(args.x509files).items()):
         logging.debug('Processing %s', fname)
         x509_objects_components = None
-        x509matches = re.finditer(r'(-----BEGIN CERTIFICATE-----'
+        x509matches = re.finditer(CERTIFICATE_RE,
-                                  '.*?'
-                                  '-----END CERTIFICATE-----)',
                                   data, re.DOTALL)
 
-        rsamatches = re.finditer(r'(-----BEGIN RSA PRIVATE KEY-----'
+        rsamatches = re.finditer(RSAPRIVKEY_RE,
-                                 '.*?'
-                                 '-----END RSA PRIVATE KEY-----)',
                                  data, re.DOTALL)
 
-        pkmatches = re.finditer(r'(-----BEGIN PRIVATE KEY-----'
+        pkmatches = re.finditer(PRIVKEY_RE,
-                                '.*?'
-                                '-----END PRIVATE KEY-----)',
                                 data, re.DOTALL)
 
         x509_objects = [crypto.load_certificate(crypto.FILETYPE_PEM,
@@ -426,24 +439,23 @@ def main():
             raise CertificateComponentException('More than one RSA private key'
                                                 ' found in input.'
                                                 ' Aborting')
-        elif rsa_objects:
+        if len(pk_objects) > 1:
+            raise CertificateComponentException('More than one private key'
+                                                ' found in input.'
+                                                ' Aborting')
+        if rsa_objects:
             if not match_cert_privkey(x509_objects[0], rsa_objects[0]):
                 raise CertificateComponentException('Provided certificate'
                                                     ' and RSA private key'
                                                     ' do not match')
-            else:
             logging.info('OK: Public key of provided certificate'
                          ' and RSA private key match')
-        elif len(pk_objects) > 1:
+
-            raise CertificateComponentException('More than one private key'
+        if pk_objects:
-                                                ' found in input.'
-                                                ' Aborting')
-        elif pk_objects:
             if not match_cert_privkey(x509_objects[0], pk_objects[0]):
                 raise CertificateComponentException('Provided certificate'
                                                     ' and private key'
                                                     ' do not match')
-            else:
             logging.info('OK: Public key of provided certificate'
                          ' and private key match')
 
@@ -452,29 +464,26 @@ def main():
             x509_objects.append(find_root(x509_objects, root_issuers))
 
         logging.debug("Print certificates in order")
-        # Need to do b'CN' to have this python3 compatible
         logging.info('Writing bundle for Subject: %s',
                      [x[1].decode('utf-8')
                       for x in x509_objects_components
-                      if x[0] == b'CN'][0])
+                      if x[0].decode('utf-8') == 'CN'][0])
 
         for x509_object in [x for x in x509_objects
                             if x.get_subject() != x.get_issuer()
                             or args.include_root]:
 
             # Stringify subject like openssl x509 -subject
-            x509_subject = \
+            x509_subject = '/'.join([
-                    '/'.join(['{0}={1}'.format(component[0].decode(),
+                f'{component[0].decode()}={component[1].decode()}'
-                                               component[1].decode())
+                for component
-                              for component in
+                in x509_object.get_subject().get_components()])
-                              x509_object.get_subject().get_components()])
 
             # Stringify issuer like openssl x509 -issuer
-            x509_issuer = \
+            x509_issuer = '/'.join([
-                '/'.join(['{0}={1}'.format(component[0].decode(),
+                f'{component[0].decode()}={component[1].decode()}'
-                                           component[1].decode())
+                for component
-                          for component in
+                in x509_object.get_issuer().get_components()])
-                          x509_object.get_issuer().get_components()])
 
             x509_not_after = \
                 datetime.strptime(str(x509_object.get_notAfter()),
@@ -509,8 +518,8 @@ def main():
                     print(rsa_object.to_cryptography_key().private_bytes(
                         encoding=serialization.Encoding.PEM,
                         format=serialization.PrivateFormat.TraditionalOpenSSL,
-                        encryption_algorithm=serialization.NoEncryption()).decode(
+                        encryption_algorithm=str(
-                            'ascii'),
+                            serialization.NoEncryption()).decode('ascii')),
                           end='')
         elif pk_objects:
             if not args.check:
@@ -525,7 +534,7 @@ def main():
 
 if __name__ == "__main__":
     try:
-        exit(main())
+        sys.exit(main())
     except CertificateComponentException as certcomponent_error:
         logging.error(certcomponent_error)
-        exit(1)
+        sys.exit(1)