Implement new options (-4/--ipv4, -6/--ipv6, -p/--port <port>).

By default both IPv4 and IPv6 is supported and order of precedence depends on OS. By using -46, IPv4 is prefered, but by using -64, IPv6 is preferd. For now the old way how to specify port (host:port) has been kept intact.
2025-06-23 11:04:31 +02:00 · 2016-10-26 18:33:00 +03:00
parent 8018209dd1
commit 66b9e079a8
3 changed files with 237 additions and 39 deletions
--- a/ssh-audit.py
+++ b/ssh-audit.py
@ -28,21 +28,22 @@ import os, io, sys, socket, struct, random, errno, getopt, re, hashlib, base64

 VERSION = 'v1.6.1.dev'

-if sys.version_info >= (3,):
+if sys.version_info >= (3,):  # pragma: nocover
 	StringIO, BytesIO = io.StringIO, io.BytesIO
 	text_type = str
 	binary_type = bytes
-else:
+else:  # pragma: nocover
 	import StringIO as _StringIO  # pylint: disable=import-error
 	StringIO = BytesIO = _StringIO.StringIO
 	text_type = unicode  # pylint: disable=undefined-variable
 	binary_type = str
-try:
+try:  # pragma: nocover
 	# pylint: disable=unused-import
-	from typing import List, Tuple, Optional, Callable, Union, Any
+	from typing import List, Set, Sequence, Tuple, Iterable
+	from typing import Callable, Optional, Union, Any
 except ImportError:  # pragma: nocover
 	pass
-try:
+try:  # pragma: nocover
 	from colorama import init as colorama_init
 	colorama_init()  # pragma: nocover
 except ImportError:  # pragma: nocover
@ -53,13 +54,16 @@ def usage(err=None):
 	# type: (Optional[str]) -> None
 	uout = Output()
 	p = os.path.basename(sys.argv[0])
-	uout.head('# {0} {1}, moo@arthepsy.eu'.format(p, VERSION))
+	uout.head('# {0} {1}, moo@arthepsy.eu\n'.format(p, VERSION))
 	if err is not None:
 		uout.fail('\n' + err)
-	uout.info('\nusage: {0} [-12bnv] [-l <level>] <host[:port]>\n'.format(p))
+	uout.info('usage: {0} [-1246pbnvl] <host>\n'.format(p))
 	uout.info('   -h,  --help             print this help')
 	uout.info('   -1,  --ssh1             force ssh version 1 only')
 	uout.info('   -2,  --ssh2             force ssh version 2 only')
+	uout.info('   -4,  --ipv4             enable IPv4 (order of precedence)')
+	uout.info('   -6,  --ipv6             enable IPv6 (order of precedence)')
+	uout.info('   -p,  --port=<port>      port to connect')
 	uout.info('   -b,  --batch            batch output')
 	uout.info('   -n,  --no-colors        disable colors')
 	uout.info('   -v,  --verbose          verbose output')
@ -69,6 +73,7 @@ def usage(err=None):


 class AuditConf(object):
+	# pylint: disable=too-many-instance-attributes
 	def __init__(self, host=None, port=22):
 		# type: (Optional[str], int) -> None
 		self.host = host
@ -79,12 +84,35 @@ class AuditConf(object):
 		self.colors = True
 		self.verbose = False
 		self.minlevel = 'info'
+		self.ipvo = ()  # type: Sequence[int]
+		self.ipv4 = False
+		self.ipv6 = False
 	
 	def __setattr__(self, name, value):
-		# type: (str, Union[str, int, bool]) -> None
+		# type: (str, Union[str, int, bool, Sequence[int]]) -> None
 		valid = False
 		if name in ['ssh1', 'ssh2', 'batch', 'colors', 'verbose']:
 			valid, value = True, True if value else False
+		elif name in ['ipv4', 'ipv6']:
+			valid = False
+			value = True if value else False
+			ipv = 4 if name == 'ipv4' else 6
+			if value:
+				value = tuple(list(self.ipvo) + [ipv])
+			else:
+				if len(self.ipvo) == 0:
+					value = (6,) if ipv == 4 else (4,)
+				else:
+					value = tuple(filter(lambda x: x != ipv, self.ipvo))
+			self.__setattr__('ipvo', value)
+		elif name == 'ipvo':
+			if isinstance(value, (tuple, list)):
+				uniq_value = utils.unique_seq(value)
+				value = tuple(filter(lambda x: x in (4, 6), uniq_value))
+				valid = True
+				ipv_both = len(value) == 0
+				object.__setattr__(self, 'ipv4', ipv_both or 4 in value)
+				object.__setattr__(self, 'ipv6', ipv_both or 6 in value)
 		elif name == 'port':
 			valid, port = True, utils.parse_int(value)
 			if port < 1 or port > 65535:
@ -105,13 +133,14 @@ class AuditConf(object):
 		# pylint: disable=too-many-branches
 		aconf = cls()
 		try:
-			sopts = 'h12bnvl:'
-			lopts = ['help', 'ssh1', 'ssh2', 'batch',
-			         'no-colors', 'verbose', 'level=']
+			sopts = 'h1246p:bnvl:'
+			lopts = ['help', 'ssh1', 'ssh2', 'ipv4', 'ipv6', 'port',
+			         'batch', 'no-colors', 'verbose', 'level=']
 			opts, args = getopt.getopt(args, sopts, lopts)
 		except getopt.GetoptError as err:
 			usage_cb(str(err))
 		aconf.ssh1, aconf.ssh2 = False, False
+		oport = None
 		for o, a in opts:
 			if o in ('-h', '--help'):
 				usage_cb()
@ -119,6 +148,12 @@ class AuditConf(object):
 				aconf.ssh1 = True
 			elif o in ('-2', '--ssh2'):
 				aconf.ssh2 = True
+			elif o in ('-4', '--ipv4'):
+				aconf.ipv4 = True
+			elif o in ('-6', '--ipv6'):
+				aconf.ipv6 = True
+			elif o in ('-p', '--port'):
+				oport = a
 			elif o in ('-b', '--batch'):
 				aconf.batch = True
 				aconf.verbose = True
@ -132,14 +167,20 @@ class AuditConf(object):
 				aconf.minlevel = a
 		if len(args) == 0:
 			usage_cb()
-		s = args[0].split(':')
-		host, port = s[0].strip(), 22
-		if len(s) > 1:
-			port = utils.parse_int(s[1])
+		if oport is not None:
+			host = args[0]
+			port = utils.parse_int(oport)
+		else:
+			s = args[0].split(':')
+			host = s[0].strip()
+			if len(s) == 2:
+				oport, port = s[1], utils.parse_int(s[1])
+			else:
+				oport, port = '22', 22
 		if not host:
 			usage_cb('host is empty')
 		if port <= 0 or port > 65535:
-			usage_cb('port {0} is not valid'.format(s[1]))
+			usage_cb('port {0} is not valid'.format(oport))
 		aconf.host = host
 		aconf.port = port
 		if not (aconf.ssh1 or aconf.ssh2):
@ -1038,24 +1079,67 @@ class SSH(object):  # pylint: disable=too-few-public-methods
 		
 		SM_BANNER_SENT = 1
 		
-		def __init__(self, host, port, cto=3.0, rto=5.0):
-			# type: (str, int, float, float) -> None
+		def __init__(self, host, port):
+			# type: (str, int) -> None
+			super(SSH.Socket, self).__init__()
 			self.__block_size = 8
 			self.__state = 0
 			self.__header = []  # type: List[text_type]
 			self.__banner = None  # type: Optional[SSH.Banner]
-			super(SSH.Socket, self).__init__()
-			try:
-				self.__sock = socket.create_connection((host, port), cto)
-				self.__sock.settimeout(rto)
-			except Exception as e:  # pylint: disable=broad-except
-				out.fail('[fail] {0}'.format(e))
-				sys.exit(1)
+			self.__host = host
+			self.__port = port
+			self.__sock = None  # type: socket.socket
 		
 		def __enter__(self):
 			# type: () -> SSH.Socket
 			return self
 		
+		def _resolve(self, ipvo):
+			# type: (Sequence[int]) -> Iterable[Tuple[int, Tuple[Any, ...]]]
+			ipvo = tuple(filter(lambda x: x in (4, 6), utils.unique_seq(ipvo)))
+			ipvo_len = len(ipvo)
+			prefer_ipvo = ipvo_len > 0
+			prefer_ipv4 = prefer_ipvo and ipvo[0] == 4
+			if len(ipvo) == 1:
+				family = {4: socket.AF_INET, 6: socket.AF_INET6}.get(ipvo[0])
+			else:
+				family = socket.AF_UNSPEC
+			try:
+				stype = socket.SOCK_STREAM
+				r = socket.getaddrinfo(self.__host, self.__port, family, stype)
+				if prefer_ipvo:
+					r = sorted(r, key=lambda x: x[0], reverse=not prefer_ipv4)
+				check = any(stype == rline[2] for rline in r)
+				for (af, socktype, proto, canonname, addr) in r:
+					if not check or socktype == socket.SOCK_STREAM:
+						yield (af, addr)
+			except socket.error as e:
+				out.fail('[exception] {0}'.format(e))
+				sys.exit(1)
+		
+		def connect(self, ipvo=(), cto=3.0, rto=5.0):
+			# type: (Sequence[int], float, float) -> None
+			err = None
+			for (af, addr) in self._resolve(ipvo):
+				s = None
+				try:
+					s = socket.socket(af, socket.SOCK_STREAM)
+					s.settimeout(cto)
+					s.connect(addr)
+					s.settimeout(rto)
+					self.__sock = s
+					return
+				except socket.error as e:
+					err = e
+					self._close_socket(s)
+			if err is None:
+				errm = 'host {0} has no DNS records'.format(self.__host)
+			else:
+				errt = (self.__host, self.__port, err)
+				errm = 'cannot connect to {0} port {1}: {2}'.format(*errt)
+			out.fail('[exception] {0}'.format(errm))
+			sys.exit(1)
+		
 		def get_banner(self, sshv=2):
 			# type: (int) -> Tuple[Optional[SSH.Banner], List[text_type]]
 			banner = 'SSH-{0}-OpenSSH_7.3'.format('1.5' if sshv == 1 else '2.0')
@ -1188,6 +1272,15 @@ class SSH(object):  # pylint: disable=too-few-public-methods
 			data = struct.pack('>Ib', plen, padding) + payload + pad_bytes
 			return self.send(data)
 		
+		def _close_socket(self, s):
+			# type: (Optional[socket.socket]) -> None
+			try:
+				if s is not None:
+					s.shutdown(socket.SHUT_RDWR)
+					s.close()
+			except:  # pylint: disable=bare-except
+				pass
+		
 		def __del__(self):
 			# type: () -> None
 			self.__cleanup()
@ -1198,11 +1291,7 @@ class SSH(object):  # pylint: disable=too-few-public-methods
 		
 		def __cleanup(self):
 			# type: () -> None
-			try:
-				self.__sock.shutdown(socket.SHUT_RDWR)
-				self.__sock.close()
-			except:  # pylint: disable=bare-except
-				pass
+			self._close_socket(self.__sock)


 class KexDH(object):
@ -1847,6 +1936,21 @@ class Utils(object):
 			return cls.to_ntext(v.encode('ascii', errors))
 		raise cls._type_err(v, 'ascii')
 	
+	@classmethod
+	def unique_seq(cls, seq):
+		# type: (Sequence[Any]) -> Sequence[Any]
+		seen = set()  # type: Set[Any]
+		
+		def _seen_add(x):
+			# type: (Any) -> bool
+			seen.add(x)
+			return False
+		
+		if isinstance(seq, tuple):
+			return tuple(x for x in seq if x not in seen and not _seen_add(x))
+		else:
+			return [x for x in seq if x not in seen and not _seen_add(x)]
+		
 	@staticmethod
 	def parse_int(v):
 		# type: (Any) -> int
@ -1863,6 +1967,7 @@ def audit(aconf, sshv=None):
 	out.verbose = aconf.verbose
 	out.minlevel = aconf.minlevel
 	s = SSH.Socket(aconf.host, aconf.port)
+	s.connect(aconf.ipvo)
 	if sshv is None:
 		sshv = 2 if aconf.ssh2 else 1
 	err = None