Disable Python2 tests. Fix pylint warnings.

.travis.yml

@@ -1,7 +1,6 @@
 language: python
 
 python:
-  - "2.7"
   - "3.5"
   - "3.6"
   - "3.7"

ssh-audit.py

@@ -91,7 +91,7 @@ def usage(err=None):
     sys.exit(1)
 
 
-class AuditConf(object):
+class AuditConf:
     # pylint: disable=too-many-instance-attributes
     def __init__(self, host=None, port=22):
         # type: (Optional[str], int) -> None
@@ -115,10 +115,10 @@ class AuditConf(object):
         # type: (str, Union[str, int, bool, Sequence[int]]) -> None
         valid = False
         if name in ['ssh1', 'ssh2', 'batch', 'client_audit', 'colors', 'verbose', 'timeout_set', 'json']:
-            valid, value = True, True if bool(value) else False
+            valid, value = True, bool(value)
         elif name in ['ipv4', 'ipv6']:
             valid = False
-            value = True if bool(value) else False
+            value = bool(value)
             ipv = 4 if name == 'ipv4' else 6
             if value:
                 value = tuple(list(self.ipvo) + [ipv])
@@ -156,7 +156,7 @@ class AuditConf(object):
             object.__setattr__(self, name, value)
 
     @classmethod
-    def from_cmdline(cls, args, usage_cb):
+    def from_cmdline(cls, args, usage_cb):  # pylint: disable=too-many-statements
         # type: (List[str], Callable[..., None]) -> AuditConf
         # pylint: disable=too-many-branches
         aconf = cls()
@@ -231,7 +231,7 @@ class AuditConf(object):
         return aconf
 
 
-class Output(object):
+class Output:
     LEVELS = ('info', 'warn', 'fail')  # type: Sequence[str]
     COLORS = {'head': 36, 'good': 32, 'warn': 33, 'fail': 31}
 
@@ -314,8 +314,8 @@ class OutputBuffer(list):
         sys.stdout = self.__stdout
 
 
-class SSH2(object):  # pylint: disable=too-few-public-methods
-    class KexDB(object):  # pylint: disable=too-few-public-methods
+class SSH2:  # pylint: disable=too-few-public-methods
+    class KexDB:  # pylint: disable=too-few-public-methods
         # pylint: disable=bad-whitespace
         WARN_OPENSSH74_UNSAFE = 'disabled (in client) since OpenSSH 7.4, unsafe algorithm'
         WARN_OPENSSH72_LEGACY = 'disabled (in client) since OpenSSH 7.2, legacy algorithm'
@@ -534,7 +534,7 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
             }
         }  # type: Dict[str, Dict[str, List[List[Optional[str]]]]]
 
-    class KexParty(object):
+    class KexParty:
         def __init__(self, enc, mac, compression, languages):
             # type: (List[text_type], List[text_type], List[text_type], List[text_type]) -> None
             self.__enc = enc
@@ -562,7 +562,7 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
             # type: () -> List[text_type]
             return self.__languages
 
-    class Kex(object):
+    class Kex:
         def __init__(self, cookie, kex_algs, key_algs, cli, srv, follows, unused=0):
             # type: (binary_type, List[text_type], List[text_type], SSH2.KexParty, SSH2.KexParty, bool, int) -> None
             self.__cookie = cookie
@@ -678,7 +678,7 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
             return kex
 
     # Obtains host keys, checks their size, and derives their fingerprints.
-    class HostKeyTest(object):
+    class HostKeyTest:
         # Tracks the RSA host key types.  As of this writing, testing one in this family yields valid results for the rest.
         RSA_FAMILY = ['ssh-rsa', 'rsa-sha2-256', 'rsa-sha2-512']
 
@@ -691,7 +691,7 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
             'ssh-rsa-cert-v01@openssh.com':     {'cert': True, 'variable_key_len': True},
 
             'ssh-ed25519':                      {'cert': False, 'variable_key_len': False},
-            'ssh-ed25519-cert-v01@openssh.com': {'cert': True,  'variable_key_len': False},
+            'ssh-ed25519-cert-v01@openssh.com': {'cert': True, 'variable_key_len': False},
         }
 
         @staticmethod
@@ -723,10 +723,10 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
                     break
 
             if kex_str is not None:
-                SSH2.HostKeyTest.__test(s, server_kex, kex_str, kex_group, SSH2.HostKeyTest.HOST_KEY_TYPES)
+                SSH2.HostKeyTest.perform_test(s, server_kex, kex_str, kex_group, SSH2.HostKeyTest.HOST_KEY_TYPES)
 
         @staticmethod
-        def __test(s, server_kex, kex_str, kex_group, host_key_types):
+        def perform_test(s, server_kex, kex_str, kex_group, host_key_types):
             hostkey_modulus_size = 0
             ca_modulus_size = 0
 
@@ -745,7 +745,8 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
                     if not s.is_connected():
                         s.connect()
                         unused = None  # pylint: disable=unused-variable
-                        unused, unused, err = s.get_banner()
+                        unused2 = None  # pylint: disable=unused-variable
+                        unused, unused2, err = s.get_banner()
                         if err is not None:
                             s.close()
                             return
@@ -794,7 +795,7 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
                             for rsa_type in SSH2.HostKeyTest.RSA_FAMILY:
                                 alg_list = SSH2.KexDB.ALGORITHMS['key'][rsa_type]
                                 alg_list.append(['using small %d-bit modulus' % hostkey_modulus_size])
-                        elif (cert is True) and ((hostkey_modulus_size < 2048) or (ca_modulus_size > 0 and ca_modulus_size < 2048)):
+                        elif (cert is True) and ((hostkey_modulus_size < 2048) or (ca_modulus_size > 0 and ca_modulus_size < 2048)):  # pylint: disable=chained-comparison
                             alg_list = SSH2.KexDB.ALGORITHMS['key'][host_key_type]
                             min_modulus = min(hostkey_modulus_size, ca_modulus_size)
                             min_modulus = min_modulus if min_modulus > 0 else max(hostkey_modulus_size, ca_modulus_size)
@@ -809,18 +810,18 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
 
     # Performs DH group exchanges to find what moduli are supported, and checks
     # their size.
-    class GEXTest(object):
+    class GEXTest:
 
-        # Creates a new connection to the server.  Returns an SSH.Socket, or
-        # None on failure.
+        # Creates a new connection to the server.  Returns True on success, or False.
         @staticmethod
         def reconnect(s, gex_alg):
             if s.is_connected():
-                return
+                return True
 
             s.connect()
             unused = None  # pylint: disable=unused-variable
-            unused, unused, err = s.get_banner()
+            unused2 = None  # pylint: disable=unused-variable
+            unused, unused2, err = s.get_banner()
             if err is not None:
                 s.close()
                 return False
@@ -873,7 +874,7 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
                         # got here, doesn't mean the server is vulnerable...
                         smallest_modulus = kex_group.get_dh_modulus_size()
 
-                    except Exception:  # pylint: disable=bare-except
+                    except Exception:
                         pass
                     finally:
                         s.close()
@@ -884,7 +885,7 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
 
                         # If we found one modulus size already, but we're about
                         # to test a larger one, don't bother.
-                        if smallest_modulus > 0 and bits >= smallest_modulus:
+                        if bits >= smallest_modulus > 0:
                             break
 
                         if SSH2.GEXTest.reconnect(s, gex_alg) is False:
@@ -895,7 +896,7 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
                             kex_group.send_init_gex(s, bits, bits, bits)
                             kex_group.recv_reply(s, False)
                             smallest_modulus = kex_group.get_dh_modulus_size()
-                        except Exception:  # pylint: disable=bare-except
+                        except Exception:
                             # import traceback
                             # print(traceback.format_exc())
                             pass
@@ -927,8 +928,8 @@ class SSH2(object):  # pylint: disable=too-few-public-methods
                         break
 
 
-class SSH1(object):
-    class CRC32(object):
+class SSH1:
+    class CRC32:
         def __init__(self):
             # type: () -> None
             self._table = [0] * 256
@@ -961,7 +962,7 @@ class SSH1(object):
             cls._crc32 = cls.CRC32()
         return cls._crc32.calc(v)
 
-    class KexDB(object):  # pylint: disable=too-few-public-methods
+    class KexDB:  # pylint: disable=too-few-public-methods
         # pylint: disable=bad-whitespace
         FAIL_PLAINTEXT = 'no encryption/integrity'
         FAIL_OPENSSH37_REMOVE = 'removed since OpenSSH 3.7'
@@ -992,7 +993,7 @@ class SSH1(object):
             }
         }  # type: Dict[str, Dict[str, List[List[Optional[str]]]]]
 
-    class PublicKeyMessage(object):
+    class PublicKeyMessage:
         def __init__(self, cookie, skey, hkey, pflags, cmask, amask):
             # type: (binary_type, Tuple[int, int, int], Tuple[int, int, int], int, int, int) -> None
             if len(skey) != 3:
@@ -1122,7 +1123,7 @@ class SSH1(object):
             return pkm
 
 
-class ReadBuf(object):
+class ReadBuf:
     def __init__(self, data=None):
         # type: (Optional[binary_type]) -> None
         super(ReadBuf, self).__init__()
@@ -1195,10 +1196,9 @@ class ReadBuf(object):
     def reset(self):
         self._buf = BytesIO()
         self._len = 0
-        super(ReadBuf, self).reset()
 
 
-class WriteBuf(object):
+class WriteBuf:
     def __init__(self, data=None):
         # type: (Optional[binary_type]) -> None
         super(WriteBuf, self).__init__()
@@ -1290,8 +1290,8 @@ class WriteBuf(object):
         self._wbuf = BytesIO()
 
 
-class SSH(object):  # pylint: disable=too-few-public-methods
-    class Protocol(object):  # pylint: disable=too-few-public-methods
+class SSH:  # pylint: disable=too-few-public-methods
+    class Protocol:  # pylint: disable=too-few-public-methods
         # pylint: disable=bad-whitespace
         SMSG_PUBLIC_KEY = 2
         MSG_DEBUG = 4
@@ -1304,14 +1304,14 @@ class SSH(object):  # pylint: disable=too-few-public-methods
         MSG_KEXDH_GEX_INIT = 32
         MSG_KEXDH_GEX_REPLY = 33
 
-    class Product(object):  # pylint: disable=too-few-public-methods
+    class Product:  # pylint: disable=too-few-public-methods
         OpenSSH = 'OpenSSH'
         DropbearSSH = 'Dropbear SSH'
         LibSSH = 'libssh'
         TinySSH = 'TinySSH'
         PuTTY = 'PuTTY'
 
-    class Software(object):
+    class Software:
         def __init__(self, vendor, product, version, patch, os_version):
             # type: (Optional[str], str, str, Optional[str], Optional[str]) -> None
             self.__vendor = vendor
@@ -1518,7 +1518,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
                 return cls(None, SSH.Product.PuTTY, mx.group(1), None, None)
             return None
 
-    class Banner(object):
+    class Banner:
         _RXP, _RXR = r'SSH-\d\.\s*?\d+', r'(-\s*([^\s]*)(?:\s+(.*))?)?'
         RX_PROTOCOL = re.compile(re.sub(r'\\d(\+?)', r'(\\d\g<1>)', _RXP))
         RX_BANNER = re.compile(r'^({0}(?:(?:-{0})*)){1}$'.format(_RXP, _RXR))
@@ -1587,7 +1587,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
                 comments = re.sub(r'\s+', ' ', comments)
             return cls(protocol, software, comments, valid_ascii)
 
-    class Fingerprint(object):
+    class Fingerprint:
         def __init__(self, fpd):
             # type: (binary_type) -> None
             self.__fpd = fpd
@@ -1606,8 +1606,8 @@ class SSH(object):  # pylint: disable=too-few-public-methods
             r = h.decode('ascii').rstrip('=')
             return u'SHA256:{0}'.format(r)
 
-    class Algorithm(object):
-        class Timeframe(object):
+    class Algorithm:
+        class Timeframe:
             def __init__(self):
                 # type: () -> None
                 self.__storage = {}  # type: Dict[str, List[Optional[str]]]
@@ -1642,7 +1642,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
                 for_srv, for_cli = pos < 2, pos > 1
                 for v in (versions or '').split(','):
                     ssh_prod, ssh_ver, is_cli = SSH.Algorithm.get_ssh_version(v)
-                    if (not ssh_ver or (is_cli and for_srv) or (not is_cli and for_cli and ssh_prod in ssh_versions)):
+                    if not ssh_ver or (is_cli and for_srv) or (not is_cli and for_cli and ssh_prod in ssh_versions):
                         continue
                     ssh_versions[ssh_prod] = ssh_ver
                 for ssh_product, ssh_version in ssh_versions.items():
@@ -1696,7 +1696,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
                 return None
             return 'available since ' + ', '.join(tv).rstrip(', ')
 
-    class Algorithms(object):
+    class Algorithms:
         def __init__(self, pkm, kex):
             # type: (Optional[SSH1.PublicKeyMessage], Optional[SSH2.Kex]) -> None
             self.__ssh1kex = pkm
@@ -1883,7 +1883,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
                     del rec[sshv]
             return software, rec
 
-        class Item(object):
+        class Item:
             def __init__(self, sshv, db):
                 # type: (int, Dict[str, Dict[str, List[List[Optional[str]]]]]) -> None
                 self.__sshv = sshv
@@ -1908,7 +1908,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
                 # type: () -> Iterable[Tuple[str, List[text_type]]]
                 return self.__storage.items()
 
-    class Security(object):  # pylint: disable=too-few-public-methods
+    class Security:  # pylint: disable=too-few-public-methods
         # Format: [starting_vuln_version, last_vuln_version, affected, CVE_ID, CVSSv2, description]
         #   affected: 1 = server, 2 = client, 4 = local
         #   Example:  if it affects servers, both remote & local, then affected
@@ -2097,7 +2097,6 @@ class SSH(object):  # pylint: disable=too-few-public-methods
                 self.__sock_map[s.fileno()] = s
             except Exception:
                 print("Warning: failed to listen on any IPv4 interfaces.")
-                pass
 
             try:
                 # Socket to listen on all IPv6 addresses.
@@ -2109,12 +2108,11 @@ class SSH(object):  # pylint: disable=too-few-public-methods
                 self.__sock_map[s.fileno()] = s
             except Exception:
                 print("Warning: failed to listen on any IPv6 interfaces.")
-                pass
 
             # If we failed to listen on any interfaces, terminate.
             if len(self.__sock_map.keys()) == 0:
                 print("Error: failed to listen on any IPv4 and IPv6 interfaces!")
-                exit(-1)
+                sys.exit(-1)
 
             # Wait for an incoming connection.  If a timeout was explicitly
             # set by the user, terminate when it elapses.
@@ -2132,7 +2130,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
 
                 if self.__timeout_set and time_elapsed >= self.__timeout:
                     print("Timeout elapsed.  Terminating...")
-                    exit(-1)
+                    sys.exit(-1)
 
             # Accept the connection.
             c, addr = self.__sock_map[fds[0][0]].accept()
@@ -2304,7 +2302,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
 
         # Returns True if this Socket is connected, otherwise False.
         def is_connected(self):
-            return (self.__sock is not None)
+            return self.__sock is not None
 
         def close(self):
             self.__cleanup()
@@ -2313,16 +2311,13 @@ class SSH(object):  # pylint: disable=too-few-public-methods
             self.__header = []
             self.__banner = None
 
-        def reset(self):
-            super(SSH.Socket, self).reset()
-
-        def _close_socket(self, s):
+        def _close_socket(self, s):  # pylint: disable=no-self-use
             # type: (Optional[socket.socket]) -> None
             try:
                 if s is not None:
                     s.shutdown(socket.SHUT_RDWR)
                     s.close()  # pragma: nocover
-            except Exception:  # pylint: disable=bare-except
+            except Exception:
                 pass
 
         def __del__(self):
@@ -2337,7 +2332,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
             self.__sock = None
 
 
-class KexDH(object):  # pragma: nocover
+class KexDH:  # pragma: nocover
     def __init__(self, kex_name, hash_alg, g, p):
         # type: (str, int, int) -> None
         self.__kex_name = kex_name
@@ -2384,7 +2379,7 @@ class KexDH(object):  # pragma: nocover
         while packet_type == SSH.Protocol.MSG_DEBUG:
             packet_type, payload = s.read_packet(2)
 
-        if packet_type != -1 and packet_type not in [SSH.Protocol.MSG_KEXDH_REPLY, SSH.Protocol.MSG_KEXDH_GEX_REPLY]:
+        if packet_type != -1 and packet_type not in [SSH.Protocol.MSG_KEXDH_REPLY, SSH.Protocol.MSG_KEXDH_GEX_REPLY]:  # pylint: disable=no-else-raise
             # TODO: change Exception to something more specific.
             raise Exception('Expected MSG_KEXDH_REPLY (%d) or MSG_KEXDH_GEX_REPLY (%d), but got %d instead.' % (SSH.Protocol.MSG_KEXDH_REPLY, SSH.Protocol.MSG_KEXDH_GEX_REPLY, packet_type))
         elif packet_type == -1:
@@ -2635,7 +2630,7 @@ class KexGroupExchange(KexDH):
         s.send_packet()
 
         packet_type, payload = s.read_packet(2)
-        if (packet_type != SSH.Protocol.MSG_KEXDH_GEX_GROUP) and (packet_type != SSH.Protocol.MSG_DEBUG):
+        if (packet_type != SSH.Protocol.MSG_KEXDH_GEX_GROUP) and (packet_type != SSH.Protocol.MSG_DEBUG):  # pylint: disable=consider-using-in
             # TODO: replace with a better exception type.
             raise Exception('Expected MSG_KEXDH_GEX_REPLY (%d), but got %d instead.' % (SSH.Protocol.MSG_KEXDH_GEX_REPLY, packet_type))
 
@@ -2933,7 +2928,7 @@ def output_recommendations(algs, software, padlen=0):
 
 
 # Output additional information & notes.
-def output_info(algs, software, client_audit, any_problems, padlen=0):
+def output_info(software, client_audit, any_problems):
     with OutputBuffer() as obuf:
         # Tell user that PuTTY cannot be hardened at the protocol-level.
         if client_audit and (software is not None) and (software.product == SSH.Product.PuTTY):
@@ -3008,14 +3003,14 @@ def output(banner, header, client_host=None, kex=None, pkm=None):
         output_algorithms(title, adb, atype, kex.server.mac, unknown_algorithms, maxlen)
     output_fingerprints(algs, True)
     perfect_config = output_recommendations(algs, software, maxlen)
-    output_info(algs, software, client_audit, not perfect_config)
+    output_info(software, client_audit, not perfect_config)
 
     # If we encountered any unknown algorithms, ask the user to report them.
     if len(unknown_algorithms) > 0:
         out.warn("\n\n!!! WARNING: unknown algorithm(s) found!: %s.  Please email the full output above to the maintainer (jtesta@positronsecurity.com), or create a Github issue at <https://github.com/jtesta/ssh-audit/issues>.\n" % ','.join(unknown_algorithms))
 
 
-class Utils(object):
+class Utils:
     @classmethod
     def _type_err(cls, v, target):
         # type: (Any, text_type) -> TypeError
@@ -3091,12 +3086,12 @@ class Utils(object):
     @classmethod
     def is_print_ascii(cls, v):
         # type: (Union[text_type, str]) -> bool
-        return cls._is_ascii(v, lambda x: x >= 32 and x <= 126)
+        return cls._is_ascii(v, lambda x: 126 >= x >= 32)
 
     @classmethod
     def to_print_ascii(cls, v, errors='replace'):
         # type: (Union[text_type, str], str) -> str
-        return cls._to_ascii(v, lambda x: x >= 32 and x <= 126, errors)
+        return cls._to_ascii(v, lambda x: 126 >= x >= 32, errors)
 
     @classmethod
     def unique_seq(cls, seq):
@@ -3187,7 +3182,7 @@ def build_struct(banner, kex=None, pkm=None, client_host=None):
         for host_key_type in host_keys.keys():
             if host_key_type in SSH2.HostKeyTest.RSA_FAMILY:
                 val = host_keys[host_key_type]
-                del(host_keys[host_key_type])
+                del host_keys[host_key_type]
                 host_keys['ssh-rsa'] = val
 
         for host_key_type in sorted(host_keys):

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist = 
-	py{27,py,py3}-{test,pylint,flake8,vulture}
+	py{py3}-{test,pylint,flake8,vulture}
 	py{35,36,37,38}-{test,mypy,pylint,flake8,vulture}
 	cov
 skipsdist = true
@@ -12,9 +12,9 @@ deps =
 	test,cov: {[testenv:cov]deps}
 	test,py{35,36,37,38}-{type,mypy}: colorama
 	py{35,36,37,38}-{type,mypy}: {[testenv:mypy]deps}
-	py{27,py,py3,35,36,37,38}-{lint,pylint},lint: {[testenv:pylint]deps}
-	py{27,py,py3,35,36,37,38}-{lint,flake8},lint: {[testenv:flake8]deps}
-	py{27,py,py3,35,36,37,38}-{lint,vulture},lint: {[testenv:vulture]deps}
+	py{py3,35,36,37,38}-{lint,pylint},lint: {[testenv:pylint]deps}
+	py{py3,35,36,37,38}-{lint,flake8},lint: {[testenv:flake8]deps}
+	py{py3,35,36,37,38}-{lint,vulture},lint: {[testenv:vulture]deps}
 setenv =
 	SSHAUDIT = {toxinidir}/ssh-audit.py
 	test: COVERAGE_FILE = {toxinidir}/.coverage.{envname}
@@ -25,10 +25,11 @@ commands =
 	test: pytest -v --junitxml={toxinidir}/reports/junit.{envname}.xml {posargs:test}
 	test: coverage report --show-missing
 	test: coverage html -d {toxinidir}/reports/html/coverage.{envname}
-	py{35,36,37,38}-{type,mypy}: {[testenv:mypy]commands}
-	py{27,py,py3,35,36,37,38}-{lint,pylint},lint: {[testenv:pylint]commands}
-	py{27,py,py3,35,36,37,38}-{lint,flake8},lint: {[testenv:flake8]commands}
-	py{27,py,py3,35,36,37,38}-{lint,vulture},lint: {[testenv:vulture]commands}
+# Temporarily disable mypy, since types have been ignored since v2.0.0.
+#	py{35,36,37,38}-{type,mypy}: {[testenv:mypy]commands}
+	py{py3,35,36,37,38}-{lint,pylint},lint: {[testenv:pylint]commands}
+	py{py3,35,36,37,38}-{lint,flake8},lint: {[testenv:flake8]commands}
+	py{py3,35,36,37,38}-{lint,vulture},lint: {[testenv:vulture]commands}
 ignore_outcome =
 	type: true
 	lint: true
@@ -113,12 +114,20 @@ reports = no
 #output-format = colorized
 indent-string = \t
 disable = 
-	locally-disabled,
-	bad-continuation,
-	multiple-imports,
-	invalid-name,
-	trailing-whitespace,
-	missing-docstring
+        bad-continuation,
+        broad-except,
+        fixme,
+        invalid-name,
+        line-too-long,
+        missing-docstring,
+        mixed-indentation,
+        no-else-return,
+        too-complex,
+        too-many-branches,
+        too-many-instance-attributes,
+        too-many-lines,
+        too-many-locals,
+        too-many-boolean-expressions
 max-complexity = 15
 max-args = 8
 max-locals = 20