diff --git a/ssh-audit.py b/ssh-audit.py
index e1f82df..b88e512 100755
--- a/ssh-audit.py
+++ b/ssh-audit.py
@@ -33,33 +33,33 @@ if sys.version_info >= (3,):
 	text_type = str
 	binary_type = bytes
 else:
-	import StringIO as _StringIO
+	import StringIO as _StringIO  # pylint: disable=import-error
 	StringIO = BytesIO = _StringIO.StringIO
 	text_type = unicode  # pylint: disable=undefined-variable
 	binary_type = str
 try:
 	# pylint: disable=unused-import
 	from typing import List, Tuple, Optional, Callable, Union, Any
-except:
+except ImportError:
 	pass
 
 
 def usage(err=None):
 	# type: (Optional[str]) -> None
-	out = Output()
+	uout = Output()
 	p = os.path.basename(sys.argv[0])
-	out.head('# {0} {1}, moo@arthepsy.eu'.format(p, VERSION))
+	uout.head('# {0} {1}, moo@arthepsy.eu'.format(p, VERSION))
 	if err is not None:
-		out.fail('\n' + err)
-	out.info('\nusage: {0} [-12bnv] [-l <level>] <host[:port]>\n'.format(p))
-	out.info('   -h,  --help             print this help')
-	out.info('   -1,  --ssh1             force ssh version 1 only')
-	out.info('   -2,  --ssh2             force ssh version 2 only')
-	out.info('   -b,  --batch            batch output')
-	out.info('   -n,  --no-colors        disable colors')
-	out.info('   -v,  --verbose          verbose output')
-	out.info('   -l,  --level=<level>    minimum output level (info|warn|fail)')
-	out.sep()
+		uout.fail('\n' + err)
+	uout.info('\nusage: {0} [-12bnv] [-l <level>] <host[:port]>\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('   -b,  --batch            batch output')
+	uout.info('   -n,  --no-colors        disable colors')
+	uout.info('   -v,  --verbose          verbose output')
+	uout.info('   -l,  --level=<level>    minimum output level (info|warn|fail)')
+	uout.sep()
 	sys.exit(1)
 
 
@@ -97,7 +97,8 @@ class AuditConf(object):
 	@classmethod
 	def from_cmdline(cls, args, usage_cb):
 		# type: (List[str], Callable[..., None]) -> AuditConf
-		conf = cls()
+		# pylint: disable=too-many-branches
+		aconf = cls()
 		try:
 			sopts = 'h12bnvl:'
 			lopts = ['help', 'ssh1', 'ssh2', 'batch',
@@ -105,25 +106,25 @@ class AuditConf(object):
 			opts, args = getopt.getopt(args, sopts, lopts)
 		except getopt.GetoptError as err:
 			usage_cb(str(err))
-		conf.ssh1, conf.ssh2 = False, False
+		aconf.ssh1, aconf.ssh2 = False, False
 		for o, a in opts:
 			if o in ('-h', '--help'):
 				usage_cb()
 			elif o in ('-1', '--ssh1'):
-				conf.ssh1 = True
+				aconf.ssh1 = True
 			elif o in ('-2', '--ssh2'):
-				conf.ssh2 = True
+				aconf.ssh2 = True
 			elif o in ('-b', '--batch'):
-				conf.batch = True
-				conf.verbose = True
+				aconf.batch = True
+				aconf.verbose = True
 			elif o in ('-n', '--no-colors'):
-				conf.colors = False
+				aconf.colors = False
 			elif o in ('-v', '--verbose'):
-				conf.verbose = True
+				aconf.verbose = True
 			elif o in ('-l', '--level'):
 				if a not in ('info', 'warn', 'fail'):
 					usage_cb('level {0} is not valid'.format(a))
-				conf.minlevel = a
+				aconf.minlevel = a
 		if len(args) == 0:
 			usage_cb()
 		s = args[0].split(':')
@@ -134,11 +135,11 @@ class AuditConf(object):
 			usage_cb('host is empty')
 		if port <= 0 or port > 65535:
 			usage_cb('port {0} is not valid'.format(s[1]))
-		conf.host = host
-		conf.port = port
-		if not (conf.ssh1 or conf.ssh2):
-			conf.ssh1, conf.ssh2 = True, True
-		return conf
+		aconf.host = host
+		aconf.port = port
+		if not (aconf.ssh1 or aconf.ssh2):
+			aconf.ssh1, aconf.ssh2 = True, True
+		return aconf
 
 
 class Output(object):
@@ -195,9 +196,9 @@ class Output(object):
 
 
 class OutputBuffer(list):
-	# pylint: disable=attribute-defined-outside-init
 	def __enter__(self):
 		# type: () -> OutputBuffer
+		# pylint: disable=attribute-defined-outside-init
 		self.__buf = StringIO()
 		self.__stdout = sys.stdout
 		sys.stdout = self.__buf
@@ -214,7 +215,7 @@ class OutputBuffer(list):
 		sys.stdout = self.__stdout
 
 
-class SSH2(object):
+class SSH2(object):  # pylint: disable=too-few-public-methods
 	class KexParty(object):
 		def __init__(self, enc, mac, compression, languages):
 			# type: (List[text_type], List[text_type], List[text_type], List[text_type]) -> None
@@ -345,7 +346,7 @@ class SSH1(object):
 			for i in range(256):
 				crc = 0
 				n = i
-				for j in range(8):
+				for _ in range(8):
 					x = (crc ^ n) & 1
 					crc = (crc >> 1) ^ (x * 0xedb88320)
 					n = n >> 1
@@ -371,7 +372,8 @@ class SSH1(object):
 			cls._crc32 = cls.CRC32()
 		return cls._crc32.calc(v)
 	
-	class KexDB(object):
+	class KexDB(object):  # pylint: disable=too-few-public-methods
+		# pylint: disable=bad-whitespace
 		FAIL_PLAINTEXT        = 'no encryption/integrity'
 		FAIL_OPENSSH37_REMOVE = 'removed since OpenSSH 3.7'
 		FAIL_NA_BROKEN        = 'not implemented in OpenSSH, broken algorithm'
@@ -451,6 +453,7 @@ class SSH1(object):
 		@property
 		def host_key_fingerprint_data(self):
 			# type: () -> binary_type
+			# pylint: disable=protected-access
 			mod = WriteBuf._create_mpint(self.host_key_public_modulus, False)
 			e = WriteBuf._create_mpint(self.host_key_public_exponent, False)
 			return mod + e
@@ -686,27 +689,28 @@ class WriteBuf(object):
 		return payload
 
 
-class SSH(object):
-	class Protocol(object):
+class SSH(object):  # pylint: disable=too-few-public-methods
+	class Protocol(object):  # pylint: disable=too-few-public-methods
+		# pylint: disable=bad-whitespace
 		SMSG_PUBLIC_KEY = 2
 		MSG_KEXINIT     = 20
 		MSG_NEWKEYS     = 21
 		MSG_KEXDH_INIT  = 30
 		MSG_KEXDH_REPLY = 32
 	
-	class Product(object):
+	class Product(object):  # pylint: disable=too-few-public-methods
 		OpenSSH = 'OpenSSH'
 		DropbearSSH = 'Dropbear SSH'
 		LibSSH = 'libssh'
 	
 	class Software(object):
-		def __init__(self, vendor, product, version, patch, os):
+		def __init__(self, vendor, product, version, patch, os_version):
 			# type: (Optional[str], str, str, Optional[str], Optional[str]) -> None
 			self.__vendor = vendor
 			self.__product = product
 			self.__version = version
 			self.__patch = patch
-			self.__os = os
+			self.__os = os_version
 		
 		@property
 		def vendor(self):
@@ -735,6 +739,7 @@ class SSH(object):
 		
 		def compare_version(self, other):
 			# type: (Union[None, SSH.Software, text_type]) -> int
+			# pylint: disable=too-many-branches
 			if other is None:
 				return 1
 			if isinstance(other, SSH.Software):
@@ -780,22 +785,22 @@ class SSH(object):
 		
 		def display(self, full=True):
 			# type: (bool) -> str
-			out = '{0} '.format(self.vendor) if self.vendor else ''
-			out += self.product
+			r = '{0} '.format(self.vendor) if self.vendor else ''
+			r += self.product
 			if self.version:
-				out += ' {0}'.format(self.version)
+				r += ' {0}'.format(self.version)
 			if full:
 				patch = self.patch or ''
 				if self.product == SSH.Product.OpenSSH:
 					mx = re.match(r'^(p\d)(.*)$', patch)
 					if mx is not None:
-						out += mx.group(1)
+						r += mx.group(1)
 						patch = mx.group(2).strip()
 				if patch:
-					out += ' ({0})'.format(patch)
+					r += ' ({0})'.format(patch)
 				if self.os:
-					out += ' running on {0}'.format(self.os)
-			return out
+					r += ' running on {0}'.format(self.os)
+			return r
 		
 		def __str__(self):
 			# type: () -> str
@@ -803,18 +808,18 @@ class SSH(object):
 		
 		def __repr__(self):
 			# type: () -> str
-			out = 'vendor={0}'.format(self.vendor) if self.vendor else ''
+			r = 'vendor={0}'.format(self.vendor) if self.vendor else ''
 			if self.product:
 				if self.vendor:
-					out += ', '
-				out += 'product={0}'.format(self.product)
+					r += ', '
+				r += 'product={0}'.format(self.product)
 			if self.version:
-				out += ', version={0}'.format(self.version)
+				r += ', version={0}'.format(self.version)
 			if self.patch:
-				out += ', patch={0}'.format(self.patch)
+				r += ', patch={0}'.format(self.patch)
 			if self.os:
-				out += ', os={0}'.format(self.os)
-			return '<{0}({1})>'.format(self.__class__.__name__, out)
+				r += ', os={0}'.format(self.os)
+			return '<{0}({1})>'.format(self.__class__.__name__, r)
 		
 		@staticmethod
 		def _fix_patch(patch):
@@ -830,7 +835,7 @@ class SSH(object):
 				return None
 		
 		@classmethod
-		def _extract_os(cls, c):
+		def _extract_os_version(cls, c):
 			# type: (Optional[str]) -> str
 			if c is None:
 				return None
@@ -859,6 +864,7 @@ class SSH(object):
 		@classmethod
 		def parse(cls, banner):
 			# type: (SSH.Banner) -> SSH.Software
+			# pylint: disable=too-many-return-statements
 			software = str(banner.software)
 			mx = re.match(r'^dropbear_([\d\.]+\d+)(.*)', software)
 			if mx:
@@ -871,14 +877,14 @@ class SSH(object):
 				patch = cls._fix_patch(mx.group(2))
 				v, p = 'OpenBSD', SSH.Product.OpenSSH
 				v = None
-				os = cls._extract_os(banner.comments)
-				return cls(v, p, mx.group(1), patch, os)
+				os_version = cls._extract_os_version(banner.comments)
+				return cls(v, p, mx.group(1), patch, os_version)
 			mx = re.match(r'^libssh-([\d\.]+\d+)(.*)', software)
 			if mx:
 				patch = cls._fix_patch(mx.group(2))
 				v, p = None, SSH.Product.LibSSH
-				os = cls._extract_os(banner.comments)
-				return cls(v, p, mx.group(1), patch, os)
+				os_version = cls._extract_os_version(banner.comments)
+				return cls(v, p, mx.group(1), patch, os_version)
 			mx = re.match(r'^RomSShell_([\d\.]+\d+)(.*)', software)
 			if mx:
 				patch = cls._fix_patch(mx.group(2))
@@ -928,22 +934,22 @@ class SSH(object):
 		
 		def __str__(self):
 			# type: () -> str
-			out = 'SSH-{0}.{1}'.format(self.protocol[0], self.protocol[1])
+			r = 'SSH-{0}.{1}'.format(self.protocol[0], self.protocol[1])
 			if self.software is not None:
-				out += '-{0}'.format(self.software)
+				r += '-{0}'.format(self.software)
 			if self.comments:
-				out += ' {0}'.format(self.comments)
-			return out
+				r += ' {0}'.format(self.comments)
+			return r
 		
 		def __repr__(self):
 			# type: () -> str
 			p = '{0}.{1}'.format(self.protocol[0], self.protocol[1])
-			out = 'protocol={0}'.format(p)
+			r = 'protocol={0}'.format(p)
 			if self.software:
-				out += ', software={0}'.format(self.software)
+				r += ', software={0}'.format(self.software)
 			if self.comments:
-				out += ', comments={0}'.format(self.comments)
-			return '<{0}({1})>'.format(self.__class__.__name__, out)
+				r += ', comments={0}'.format(self.comments)
+			return '<{0}({1})>'.format(self.__class__.__name__, r)
 		
 		@classmethod
 		def parse(cls, banner):
@@ -982,7 +988,8 @@ class SSH(object):
 			r = h.decode('ascii').rstrip('=')
 			return u'SHA256:{0}'.format(r)
 	
-	class Security(object):
+	class Security(object):  # pylint: disable=too-few-public-methods
+		# pylint: disable=bad-whitespace
 		CVE = {
 			'Dropbear SSH': [
 				['0.44', '2015.71', 1, 'CVE-2016-3116', 5.5, 'bypass command restrictions via xauth command injection'],
@@ -1031,7 +1038,7 @@ class SSH(object):
 			try:
 				self.__sock = socket.create_connection((host, port), cto)
 				self.__sock.settimeout(rto)
-			except Exception as e:
+			except Exception as e:  # pylint: disable=broad-except
 				out.fail('[fail] {0}'.format(e))
 				sys.exit(1)
 		
@@ -1184,7 +1191,7 @@ class SSH(object):
 			try:
 				self.__sock.shutdown(socket.SHUT_RDWR)
 				self.__sock.close()
-			except:
+			except:  # pylint: disable=bare-except
 				pass
 
 
@@ -1236,7 +1243,8 @@ class KexGroup14(KexDH):
 		super(KexGroup14, self).__init__('sha1', 2, p)
 
 
-class KexDB(object):
+class KexDB(object):  # pylint: disable=too-few-public-methods
+	# pylint: disable=bad-whitespace
 	WARN_OPENSSH72_LEGACY = 'disabled (in client) since OpenSSH 7.2, legacy algorithm'
 	FAIL_OPENSSH70_LEGACY = 'removed since OpenSSH 7.0, legacy algorithm'
 	FAIL_OPENSSH70_WEAK   = 'removed (in server) and disabled (in client) since OpenSSH 7.0, weak algorithm'
@@ -1397,7 +1405,7 @@ def get_ssh_timeframe(alg_pairs, for_server=True):
 	# type: (List[Tuple[int, Dict[str, Dict[str, List[List[str]]]], List[Tuple[str, List[text_type]]]]], bool) -> Dict[str, List[Optional[str]]]
 	timeframe = {}  # type: Dict[str, List[Optional[str]]]
 	for alg_pair in alg_pairs:
-		sshv, alg_db = alg_pair[0], alg_pair[1]
+		alg_db = alg_pair[1]
 		for alg_set in alg_pair[2]:
 			alg_type, alg_list = alg_set
 			for alg_name in alg_list:
@@ -1448,6 +1456,7 @@ def get_alg_pairs(kex, pkm):
 
 def get_alg_recommendations(software, kex, pkm, for_server=True):
 	# type: (SSH.Software, SSH2.Kex, SSH1.PublicKeyMessage, bool) -> Tuple[SSH.Software, Dict[int, Dict[str, Dict[str, Dict[str, int]]]]]
+	# pylint: disable=too-many-locals,too-many-statements
 	alg_pairs = get_alg_pairs(kex, pkm)
 	vproducts = [SSH.Product.OpenSSH,
 	             SSH.Product.DropbearSSH,
@@ -1833,19 +1842,19 @@ class Utils(object):
 		# type: (Any) -> int
 		try:
 			return int(v)
-		except:
+		except:  # pylint: disable=bare-except
 			return 0
 
 
-def audit(conf, sshv=None):
+def audit(aconf, sshv=None):
 	# type: (AuditConf, Optional[int]) -> None
-	out.batch = conf.batch
-	out.colors = conf.colors
-	out.verbose = conf.verbose
-	out.minlevel = conf.minlevel
-	s = SSH.Socket(conf.host, conf.port)
+	out.batch = aconf.batch
+	out.colors = aconf.colors
+	out.verbose = aconf.verbose
+	out.minlevel = aconf.minlevel
+	s = SSH.Socket(aconf.host, aconf.port)
 	if sshv is None:
-		sshv = 2 if conf.ssh2 else 1
+		sshv = 2 if aconf.ssh2 else 1
 	err = None
 	banner, header = s.get_banner(sshv)
 	if banner is None:
@@ -1858,8 +1867,8 @@ def audit(conf, sshv=None):
 			except UnicodeDecodeError:
 				payload_txt = u'"{0}"'.format(repr(payload).lstrip('b')[1:-1])
 			if payload_txt == u'Protocol major versions differ.':
-				if sshv == 2 and conf.ssh1:
-					audit(conf, 1)
+				if sshv == 2 and aconf.ssh1:
+					audit(aconf, 1)
 					return
 			err = '[exception] error reading packet ({0})'.format(payload_txt)
 		else: