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ssh-audit/ssh-audit.py

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#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
The MIT License (MIT)
Copyright (C) 2016 Andris Raugulis (moo@arthepsy.eu)
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
"""
from __future__ import print_function
import os, io, sys, socket, struct, random, errno, getopt, re, hashlib, base64
VERSION = 'v1.5.1.dev'
def usage(err=None):
out = Output()
p = os.path.basename(sys.argv[0])
out.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()
sys.exit(1)
class AuditConf(object):
def __init__(self, host=None, port=22):
self.host = host
self.port = port
self.ssh1 = True
self.ssh2 = True
self.batch = False
self.colors = True
self.verbose = False
self.minlevel = 'info'
def __setattr__(self, name, value):
valid = False
if name in ['ssh1', 'ssh2', 'batch', 'colors', 'verbose']:
valid, value = True, True if value else False
elif name == 'port':
valid, port = True, utils.parse_int(value)
if port < 1 or port > 65535:
raise ValueError('invalid port: {0}'.format(value))
value = port
elif name in ['minlevel']:
if value not in ('info', 'warn', 'fail'):
raise ValueError('invalid level: {0}'.format(value))
valid = True
elif name == 'host':
valid = True
if valid:
object.__setattr__(self, name, value)
@classmethod
def from_cmdline(cls, args, usage_cb):
conf = cls()
try:
sopts = 'h12bnvl:'
lopts = ['help', 'ssh1', 'ssh2', 'batch',
'no-colors', 'verbose', 'level=']
opts, args = getopt.getopt(args, sopts, lopts)
except getopt.GetoptError as err:
usage_cb(str(err))
conf.ssh1, conf.ssh2 = False, False
for o, a in opts:
if o in ('-h', '--help'):
usage_cb()
elif o in ('-1', '--ssh1'):
conf.ssh1 = True
elif o in ('-2', '--ssh2'):
conf.ssh2 = True
elif o in ('-b', '--batch'):
conf.batch = True
conf.verbose = True
elif o in ('-n', '--no-colors'):
conf.colors = False
elif o in ('-v', '--verbose'):
conf.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
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 not host:
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
class Output(object):
LEVELS = ['info', 'warn', 'fail']
COLORS = {'head': 36, 'good': 32, 'warn': 33, 'fail': 31}
def __init__(self):
self.batch = False
self.colors = True
self.verbose = False
self.__minlevel = 0
@property
def minlevel(self):
if self.__minlevel < len(self.LEVELS):
return self.LEVELS[self.__minlevel]
return 'unknown'
@minlevel.setter
def minlevel(self, name):
self.__minlevel = self.getlevel(name)
def getlevel(self, name):
cname = 'info' if name == 'good' else name
if cname not in self.LEVELS:
return sys.maxsize
return self.LEVELS.index(cname)
def sep(self):
if not self.batch:
print()
def _colorized(self, color):
return lambda x: print(u'{0}{1}\033[0m'.format(color, x))
def __getattr__(self, name):
if name == 'head' and self.batch:
return lambda x: None
if not self.getlevel(name) >= self.__minlevel:
return lambda x: None
if self.colors and os.name == 'posix' and name in self.COLORS:
color = u'\033[0;{0}m'.format(self.COLORS[name])
return self._colorized(color)
else:
return lambda x: print(u'{0}'.format(x))
class OutputBuffer(list):
def __enter__(self):
self.__buf = utils.StringIO()
self.__stdout = sys.stdout
sys.stdout = self.__buf
return self
def flush(self):
for line in self:
print(line)
def __exit__(self, *args):
self.extend(self.__buf.getvalue().splitlines())
sys.stdout = self.__stdout
class SSH2(object):
class KexParty(object):
def __init__(self, enc, mac, compression, languages):
self.__enc = enc
self.__mac = mac
self.__compression = compression
self.__languages = languages
@property
def encryption(self):
return self.__enc
@property
def mac(self):
return self.__mac
@property
def compression(self):
return self.__compression
@property
def languages(self):
return self.__languages
class Kex(object):
def __init__(self, cookie, kex_algs, key_algs, cli, srv, follows, unused=0):
self.__cookie = cookie
self.__kex_algs = kex_algs
self.__key_algs = key_algs
self.__client = cli
self.__server = srv
self.__follows = follows
self.__unused = unused
@property
def cookie(self):
return self.__cookie
@property
def kex_algorithms(self):
return self.__kex_algs
@property
def key_algorithms(self):
return self.__key_algs
# client_to_server
@property
def client(self):
return self.__client
# server_to_client
@property
def server(self):
return self.__server
@property
def follows(self):
return self.__follows
@property
def unused(self):
return self.__unused
def write(self, wbuf):
wbuf.write(self.cookie)
wbuf.write_list(self.kex_algorithms)
wbuf.write_list(self.key_algorithms)
wbuf.write_list(self.client.encryption)
wbuf.write_list(self.server.encryption)
wbuf.write_list(self.client.mac)
wbuf.write_list(self.server.mac)
wbuf.write_list(self.client.compression)
wbuf.write_list(self.server.compression)
wbuf.write_list(self.client.languages)
wbuf.write_list(self.server.languages)
wbuf.write_bool(self.follows)
wbuf.write_int(self.__unused)
@property
def payload(self):
wbuf = WriteBuf()
self.write(wbuf)
return wbuf.write_flush()
@classmethod
def parse(cls, payload):
buf = ReadBuf(payload)
cookie = buf.read(16)
kex_algs = buf.read_list()
key_algs = buf.read_list()
cli_enc = buf.read_list()
srv_enc = buf.read_list()
cli_mac = buf.read_list()
srv_mac = buf.read_list()
cli_compression = buf.read_list()
srv_compression = buf.read_list()
cli_languages = buf.read_list()
srv_languages = buf.read_list()
follows = buf.read_bool()
unused = buf.read_int()
cli = SSH2.KexParty(cli_enc, cli_mac, cli_compression, cli_languages)
srv = SSH2.KexParty(srv_enc, srv_mac, srv_compression, srv_languages)
kex = cls(cookie, kex_algs, key_algs, cli, srv, follows, unused)
return kex
class SSH1(object):
class CRC32(object):
def __init__(self):
self._table = [0] * 256
for i in range(256):
crc = 0
n = i
for j in range(8):
x = (crc ^ n) & 1
crc = (crc >> 1) ^ (x * 0xedb88320)
n = n >> 1
self._table[i] = crc
def calc(self, v):
crc, l = 0, len(v)
for i in range(l):
n = ord(v[i:i + 1])
n = n ^ (crc & 0xff)
crc = (crc >> 8) ^ self._table[n]
return crc
_crc32 = None
CIPHERS = ['none', 'idea', 'des', '3des', 'tss', 'rc4', 'blowfish']
AUTHS = [None, 'rhosts', 'rsa', 'password', 'rhosts_rsa', 'tis', 'kerberos']
@classmethod
def crc32(cls, v):
if cls._crc32 is None:
cls._crc32 = cls.CRC32()
return cls._crc32.calc(v)
class KexDB(object):
FAIL_PLAINTEXT = 'no encryption/integrity'
FAIL_OPENSSH37_REMOVE = 'removed since OpenSSH 3.7'
FAIL_NA_BROKEN = 'not implemented in OpenSSH, broken algorithm'
FAIL_NA_UNSAFE = 'not implemented in OpenSSH (server), unsafe algorithm'
TEXT_CIPHER_IDEA = 'cipher used by commercial SSH'
ALGORITHMS = {
'key': {
'ssh-rsa1': [['1.2.2']],
},
'enc': {
'none': [['1.2.2'], [FAIL_PLAINTEXT]],
'idea': [[None], [], [], [TEXT_CIPHER_IDEA]],
'des': [['2.3.0C'], [FAIL_NA_UNSAFE]],
'3des': [['1.2.2']],
'tss': [[''], [FAIL_NA_BROKEN]],
'rc4': [[], [FAIL_NA_BROKEN]],
'blowfish': [['1.2.2']],
},
'aut': {
'rhosts': [['1.2.2', '3.6'], [FAIL_OPENSSH37_REMOVE]],
'rsa': [['1.2.2']],
'password': [['1.2.2']],
'rhosts_rsa': [['1.2.2']],
'tis': [['1.2.2']],
'kerberos': [['1.2.2', '3.6'], [FAIL_OPENSSH37_REMOVE]],
}
}
class PublicKeyMessage(object):
def __init__(self, cookie, skey, hkey, pflags, cmask, amask):
assert len(skey) == 3
assert len(hkey) == 3
self.__cookie = cookie
self.__server_key = skey
self.__host_key = hkey
self.__protocol_flags = pflags
self.__supported_ciphers_mask = cmask
self.__supported_authentications_mask = amask
@property
def cookie(self):
return self.__cookie
@property
def server_key_bits(self):
return self.__server_key[0]
@property
def server_key_public_exponent(self):
return self.__server_key[1]
@property
def server_key_public_modulus(self):
return self.__server_key[2]
@property
def host_key_bits(self):
return self.__host_key[0]
@property
def host_key_public_exponent(self):
return self.__host_key[1]
@property
def host_key_public_modulus(self):
return self.__host_key[2]
@property
def host_key_fingerprint_data(self):
mod = WriteBuf._create_mpint(self.host_key_public_modulus, False)
e = WriteBuf._create_mpint(self.host_key_public_exponent, False)
return mod + e
@property
def protocol_flags(self):
return self.__protocol_flags
@property
def supported_ciphers_mask(self):
return self.__supported_ciphers_mask
@property
def supported_ciphers(self):
ciphers = []
for i in range(len(SSH1.CIPHERS)):
if self.__supported_ciphers_mask & (1 << i) != 0:
ciphers.append(SSH1.CIPHERS[i])
return ciphers
@property
def supported_authentications_mask(self):
return self.__supported_authentications_mask
@property
def supported_authentications(self):
auths = []
for i in range(1, len(SSH1.AUTHS)):
if self.__supported_authentications_mask & (1 << i) != 0:
auths.append(SSH1.AUTHS[i])
return auths
def write(self, wbuf):
wbuf.write(self.cookie)
wbuf.write_int(self.server_key_bits)
wbuf.write_mpint1(self.server_key_public_exponent)
wbuf.write_mpint1(self.server_key_public_modulus)
wbuf.write_int(self.host_key_bits)
wbuf.write_mpint1(self.host_key_public_exponent)
wbuf.write_mpint1(self.host_key_public_modulus)
wbuf.write_int(self.protocol_flags)
wbuf.write_int(self.supported_ciphers_mask)
wbuf.write_int(self.supported_authentications_mask)
@property
def payload(self):
wbuf = WriteBuf()
self.write(wbuf)
return wbuf.write_flush()
@classmethod
def parse(cls, payload):
buf = ReadBuf(payload)
cookie = buf.read(8)
server_key_bits = buf.read_int()
server_key_exponent = buf.read_mpint1()
server_key_modulus = buf.read_mpint1()
skey = (server_key_bits, server_key_exponent, server_key_modulus)
host_key_bits = buf.read_int()
host_key_exponent = buf.read_mpint1()
host_key_modulus = buf.read_mpint1()
hkey = (host_key_bits, host_key_exponent, host_key_modulus)
pflags = buf.read_int()
cmask = buf.read_int()
amask = buf.read_int()
pkm = cls(cookie, skey, hkey, pflags, cmask, amask)
return pkm
class ReadBuf(object):
def __init__(self, data=None):
super(ReadBuf, self).__init__()
self._buf = utils.BytesIO(data) if data else utils.BytesIO()
self._len = len(data) if data else 0
@property
def unread_len(self):
return self._len - self._buf.tell()
def read(self, size):
return self._buf.read(size)
def read_byte(self):
return struct.unpack('B', self.read(1))[0]
def read_bool(self):
return self.read_byte() != 0
def read_int(self):
return struct.unpack('>I', self.read(4))[0]
def read_list(self):
list_size = self.read_int()
return self.read(list_size).decode().split(',')
def read_string(self):
n = self.read_int()
return self.read(n)
@classmethod
def _parse_mpint(cls, v, pad, sf):
r = 0
if len(v) % 4:
v = pad * (4 - (len(v) % 4)) + v
for i in range(0, len(v), 4):
r = (r << 32) | struct.unpack(sf, v[i:i + 4])[0]
return r
def read_mpint1(self):
# NOTE: Data Type Enc @ http://www.snailbook.com/docs/protocol-1.5.txt
bits = struct.unpack('>H', self.read(2))[0]
n = (bits + 7) // 8
return self._parse_mpint(self.read(n), b'\x00', '>I')
def read_mpint2(self):
# NOTE: Section 5 @ https://www.ietf.org/rfc/rfc4251.txt
v = self.read_string()
if len(v) == 0:
return 0
pad, sf = (b'\xff', '>i') if ord(v[0:1]) & 0x80 else (b'\x00', '>I')
return self._parse_mpint(v, pad, sf)
def read_line(self):
return self._buf.readline().rstrip().decode('utf-8')
class WriteBuf(object):
def __init__(self, data=None):
super(WriteBuf, self).__init__()
self._wbuf = io.BytesIO(data) if data else io.BytesIO()
def write(self, data):
self._wbuf.write(data)
return self
def write_byte(self, v):
return self.write(struct.pack('B', v))
def write_bool(self, v):
return self.write_byte(1 if v else 0)
def write_int(self, v):
return self.write(struct.pack('>I', v))
def write_string(self, v):
if not isinstance(v, bytes):
v = bytes(bytearray(v, 'utf-8'))
self.write_int(len(v))
return self.write(v)
def write_list(self, v):
return self.write_string(u','.join(v))
@classmethod
def _bitlength(cls, n):
try:
return n.bit_length()
except AttributeError:
return len(bin(n)) - (2 if n > 0 else 3)
@classmethod
def _create_mpint(cls, n, signed=True, bits=None):
if bits is None:
bits = cls._bitlength(n)
length = bits // 8 + (1 if n != 0 else 0)
ql = (length + 7) // 8
fmt, v2 = '>{0}Q'.format(ql), [b'\x00'] * ql
for i in range(ql):
v2[ql - i - 1] = (n & 0xffffffffffffffff)
n >>= 64
data = bytes(struct.pack(fmt, *v2)[-length:])
if not signed:
data = data.lstrip(b'\x00')
elif data.startswith(b'\xff\x80'):
data = data[1:]
return data
def write_mpint1(self, n):
# NOTE: Data Type Enc @ http://www.snailbook.com/docs/protocol-1.5.txt
bits = self._bitlength(n)
data = self._create_mpint(n, False, bits)
self.write(struct.pack('>H', bits))
return self.write(data)
def write_mpint2(self, n):
# NOTE: Section 5 @ https://www.ietf.org/rfc/rfc4251.txt
data = self._create_mpint(n)
return self.write_string(data)
def write_line(self, v):
if not isinstance(v, bytes):
v = bytes(bytearray(v, 'utf-8'))
v += b'\r\n'
return self.write(v)
def write_flush(self):
payload = self._wbuf.getvalue()
self._wbuf.truncate(0)
self._wbuf.seek(0)
return payload
class SSH(object):
class Protocol(object):
SMSG_PUBLIC_KEY = 2
MSG_KEXINIT = 20
MSG_NEWKEYS = 21
MSG_KEXDH_INIT = 30
MSG_KEXDH_REPLY = 32
class Product(object):
OpenSSH = 'OpenSSH'
DropbearSSH = 'Dropbear SSH'
LibSSH = 'libssh'
class Software(object):
def __init__(self, vendor, product, version, patch, os):
self.__vendor = vendor
self.__product = product
self.__version = version
self.__patch = patch
self.__os = os
@property
def vendor(self):
return self.__vendor
@property
def product(self):
return self.__product
@property
def version(self):
return self.__version
@property
def patch(self):
return self.__patch
@property
def os(self):
return self.__os
def compare_version(self, other):
if other is None:
return 1
if isinstance(other, self.__class__):
other = '{0}{1}'.format(other.version, other.patch or '')
else:
other = str(other)
mx = re.match(r'^([\d\.]+\d+)(.*)$', other)
if mx:
oversion, opatch = mx.group(1), mx.group(2).strip()
else:
oversion, opatch = other, ''
if self.version < oversion:
return -1
elif self.version > oversion:
return 1
spatch = self.patch or ''
if self.product == SSH.Product.DropbearSSH:
if not re.match(r'^test\d.*$', opatch):
opatch = 'z{0}'.format(opatch)
if not re.match(r'^test\d.*$', spatch):
spatch = 'z{0}'.format(spatch)
elif self.product == SSH.Product.OpenSSH:
mx1 = re.match(r'^p\d(.*)', opatch)
mx2 = re.match(r'^p\d(.*)', spatch)
if not (mx1 and mx2):
if mx1:
opatch = mx1.group(1)
if mx2:
spatch = mx2.group(1)
if spatch < opatch:
return -1
elif spatch > opatch:
return 1
return 0
def between_versions(self, vfrom, vtill):
if vfrom and self.compare_version(vfrom) < 0:
return False
if vtill and self.compare_version(vtill) > 0:
return False
return True
def display(self, full=True):
out = '{0} '.format(self.vendor) if self.vendor else ''
out += self.product
if self.version:
out += ' {0}'.format(self.version)
if full:
patch = self.patch or ''
if self.product == SSH.Product.OpenSSH:
mx = re.match('^(p\d)(.*)$', patch)
if mx is not None:
out += mx.group(1)
patch = mx.group(2).strip()
if patch:
out += ' ({0})'.format(patch)
if self.os:
out += ' running on {0}'.format(self.os)
return out
def __str__(self):
return self.display()
def __repr__(self):
out = 'vendor={0}'.format(self.vendor) if self.vendor else ''
if self.product:
if self.vendor:
out += ', '
out += 'product={0}'.format(self.product)
if self.version:
out += ', version={0}'.format(self.version)
if self.patch:
out += ', patch={0}'.format(self.patch)
if self.os:
out += ', os={0}'.format(self.os)
return '<{0}({1})>'.format(self.__class__.__name__, out)
@staticmethod
def _fix_patch(patch):
return re.sub(r'^[-_\.]+', '', patch) or None
@staticmethod
def _fix_date(d):
if d is not None and len(d) == 8:
return '{0}-{1}-{2}'.format(d[:4], d[4:6], d[6:8])
else:
return None
@classmethod
def _extract_os(cls, c):
if c is None:
return None
mx = re.match(r'^NetBSD(?:_Secure_Shell)?(?:[\s-]+(\d{8})(.*))?$', c)
if mx:
d = cls._fix_date(mx.group(1))
return 'NetBSD' if d is None else 'NetBSD ({0})'.format(d)
mx = re.match(r'^FreeBSD(?:\slocalisations)?[\s-]+(\d{8})(.*)$', c)
if not mx:
mx = re.match(r'^[^@]+@FreeBSD\.org[\s-]+(\d{8})(.*)$', c)
if mx:
d = cls._fix_date(mx.group(1))
return 'FreeBSD' if d is None else 'FreeBSD ({0})'.format(d)
w = ['RemotelyAnywhere', 'DesktopAuthority', 'RemoteSupportManager']
for win_soft in w:
mx = re.match(r'^in ' + win_soft + ' ([\d\.]+\d)$', c)
if mx:
ver = mx.group(1)
return 'Microsoft Windows ({0} {1})'.format(win_soft, ver)
generic = ['NetBSD', 'FreeBSD']
for g in generic:
if c.startswith(g) or c.endswith(g):
return g
return None
@classmethod
def parse(cls, banner):
software = str(banner.software)
mx = re.match(r'^dropbear_([\d\.]+\d+)(.*)', software)
if mx:
patch = cls._fix_patch(mx.group(2))
v, p = 'Matt Johnston', SSH.Product.DropbearSSH
v = None
return cls(v, p, mx.group(1), patch, None)
mx = re.match(r'^OpenSSH[_\.-]+([\d\.]+\d+)(.*)', software)
if mx:
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)
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)
mx = re.match(r'^RomSShell_([\d\.]+\d+)(.*)', software)
if mx:
patch = cls._fix_patch(mx.group(2))
v, p = 'Allegro Software', 'RomSShell'
return cls(v, p, mx.group(1), patch, None)
mx = re.match(r'^mpSSH_([\d\.]+\d+)', software)
if mx:
v, p = 'HP', 'iLO (Integrated Lights-Out) sshd'
return cls(v, p, mx.group(1), None, None)
mx = re.match(r'^Cisco-([\d\.]+\d+)', software)
if mx:
v, p = 'Cisco', 'IOS/PIX sshd'
return cls(v, p, mx.group(1), None, None)
return None
class Banner(object):
_RXP, _RXR = r'SSH-\d\.\s*?\d+', r'(-\s*([^\s]*)(?:\s+(.*))?)?'
RX_PROTOCOL = re.compile(re.sub(r'\\d(\+?)', '(\\d\g<1>)', _RXP))
RX_BANNER = re.compile(r'^({0}(?:(?:-{0})*)){1}$'.format(_RXP, _RXR))
def __init__(self, protocol, software, comments):
self.__protocol = protocol
self.__software = software
self.__comments = comments
@property
def protocol(self):
return self.__protocol
@property
def software(self):
return self.__software
@property
def comments(self):
return self.__comments
def __str__(self):
out = 'SSH-{0}.{1}'.format(self.protocol[0], self.protocol[1])
if self.software is not None:
out += '-{0}'.format(self.software)
if self.comments:
out += ' {0}'.format(self.comments)
return out
def __repr__(self):
p = '{0}.{1}'.format(self.protocol[0], self.protocol[1])
out = 'protocol={0}'.format(p)
if self.software:
out += ', software={0}'.format(self.software)
if self.comments:
out += ', comments={0}'.format(self.comments)
return '<{0}({1})>'.format(self.__class__.__name__, out)
@classmethod
def parse(cls, banner):
mx = cls.RX_BANNER.match(banner)
if mx is None:
return None
protocol = min(re.findall(cls.RX_PROTOCOL, mx.group(1)))
protocol = (int(protocol[0]), int(protocol[1]))
software = (mx.group(3) or '').strip() or None
if software is None and (mx.group(2) or '').startswith('-'):
software = ''
comments = (mx.group(4) or '').strip() or None
if comments is not None:
comments = re.sub('\s+', ' ', comments)
return cls(protocol, software, comments)
class Fingerprint(object):
def __init__(self, fpd):
self.__fpd = fpd
@property
def md5(self):
h = hashlib.md5(self.__fpd).hexdigest()
h = u':'.join(h[i:i + 2] for i in range(0, len(h), 2))
return u'MD5:{0}'.format(h)
@property
def sha256(self):
h = base64.b64encode(hashlib.sha256(self.__fpd).digest())
h = h.decode().rstrip('=')
return u'SHA256:{0}'.format(h)
class Security(object):
CVE = {
'Dropbear SSH': [
['0.44', '2015.71', 1, 'CVE-2016-3116', 5.5, 'bypass command restrictions via xauth command injection'],
['0.28', '2013.58', 1, 'CVE-2013-4434', 5.0, 'discover valid usernames through different time delays'],
['0.28', '2013.58', 1, 'CVE-2013-4421', 5.0, 'cause DoS (memory consumption) via a compressed packet'],
['0.52', '2011.54', 1, 'CVE-2012-0920', 7.1, 'execute arbitrary code or bypass command restrictions'],
['0.40', '0.48.1', 1, 'CVE-2007-1099', 7.5, 'conduct a MitM attack (no warning for hostkey mismatch)'],
['0.28', '0.47', 1, 'CVE-2006-1206', 7.5, 'cause DoS (slot exhaustion) via large number of connections'],
['0.39', '0.47', 1, 'CVE-2006-0225', 4.6, 'execute arbitrary commands via scp with crafted filenames'],
['0.28', '0.46', 1, 'CVE-2005-4178', 6.5, 'execute arbitrary code via buffer overflow vulnerability'],
['0.28', '0.42', 1, 'CVE-2004-2486', 7.5, 'execute arbitrary code via DSS verification code']],
'libssh': [
['0.1', '0.7.2', 1, 'CVE-2016-0739', 4.3, 'conduct a MitM attack (weakness in DH key generation)'],
['0.5.1', '0.6.4', 1, 'CVE-2015-3146', 5.0, 'cause DoS via kex packets (null pointer dereference)'],
['0.5.1', '0.6.3', 1, 'CVE-2014-8132', 5.0, 'cause DoS via kex init packet (dangling pointer)'],
['0.4.7', '0.6.2', 1, 'CVE-2014-0017', 1.9, 'leak data via PRNG state reuse on forking servers'],
['0.4.7', '0.5.3', 1, 'CVE-2013-0176', 4.3, 'cause DoS via kex packet (null pointer dereference)'],
['0.4.7', '0.5.2', 1, 'CVE-2012-6063', 7.5, 'cause DoS or execute arbitrary code via sftp (double free)'],
['0.4.7', '0.5.2', 1, 'CVE-2012-4562', 7.5, 'cause DoS or execute arbitrary code (overflow check)'],
['0.4.7', '0.5.2', 1, 'CVE-2012-4561', 5.0, 'cause DoS via unspecified vectors (invalid pointer)'],
['0.4.7', '0.5.2', 1, 'CVE-2012-4560', 7.5, 'cause DoS or execute arbitrary code (buffer overflow)'],
['0.4.7', '0.5.2', 1, 'CVE-2012-4559', 6.8, 'cause DoS or execute arbitrary code (double free)']]
}
TXT = {
'Dropbear SSH': [
['0.28', '0.34', 1, 'remote root exploit', 'remote format string buffer overflow exploit (exploit-db#387)']],
'libssh': [
['0.3.3', '0.3.3', 1, 'null pointer check', 'missing null pointer check in "crypt_set_algorithms_server"'],
['0.3.3', '0.3.3', 1, 'integer overflow', 'integer overflow in "buffer_get_data"'],
['0.3.3', '0.3.3', 3, 'heap overflow', 'heap overflow in "packet_decrypt"']]
}
class Socket(ReadBuf, WriteBuf):
class InsufficientReadException(Exception):
pass
SM_BANNER_SENT = 1
def __init__(self, host, port, cto=3.0, rto=5.0):
self.__block_size = 8
self.__state = 0
self.__header = []
self.__banner = None
super(SSH.Socket, self).__init__()
try:
self.__sock = socket.create_connection((host, port), cto)
self.__sock.settimeout(rto)
except Exception as e:
out.fail('[fail] {0}'.format(e))
sys.exit(1)
def __enter__(self):
return self
def get_banner(self, sshv=2):
banner = 'SSH-{0}-OpenSSH_7.3'.format('1.5' if sshv == 1 else '2.0')
rto = self.__sock.gettimeout()
self.__sock.settimeout(0.7)
s, e = self.recv()
self.__sock.settimeout(rto)
if s < 0:
return self.__banner, self.__header
if self.__state < self.SM_BANNER_SENT:
self.send_banner(banner)
while self.__banner is None:
if not s > 0:
s, e = self.recv()
if s < 0:
break
while self.__banner is None and self.unread_len > 0:
line = self.read_line()
if len(line.strip()) == 0:
continue
if self.__banner is None:
self.__banner = SSH.Banner.parse(line)
if self.__banner is not None:
continue
self.__header.append(line)
s = 0
return self.__banner, self.__header
def recv(self, size=2048):
try:
data = self.__sock.recv(size)
except socket.timeout as e:
r = 0 if e.strerror == 'timed out' else -1
return (r, e)
except socket.error as e:
r = 0 if e.errno in (errno.EAGAIN, errno.EWOULDBLOCK) else -1
return (r, e)
if len(data) == 0:
return (-1, None)
pos = self._buf.tell()
self._buf.seek(0, 2)
self._buf.write(data)
self._len += len(data)
self._buf.seek(pos, 0)
return (len(data), None)
def send(self, data):
try:
self.__sock.send(data)
return (0, None)
except socket.error as e:
return (-1, e)
self.__sock.send(data)
def send_banner(self, banner):
self.send(banner.encode() + b'\r\n')
if self.__state < self.SM_BANNER_SENT:
self.__state = self.SM_BANNER_SENT
def ensure_read(self, size):
while self.unread_len < size:
s, e = self.recv()
if s < 0:
raise SSH.Socket.InsufficientReadException(e)
def read_packet(self, sshv=2):
try:
header = WriteBuf()
self.ensure_read(4)
packet_length = self.read_int()
header.write_int(packet_length)
# XXX: validate length
if sshv == 1:
padding_length = (8 - packet_length % 8)
self.ensure_read(padding_length)
padding = self.read(padding_length)
header.write(padding)
payload_length = packet_length
check_size = padding_length + payload_length
else:
self.ensure_read(1)
padding_length = self.read_byte()
header.write_byte(padding_length)
payload_length = packet_length - padding_length - 1
check_size = 4 + 1 + payload_length + padding_length
if check_size % self.__block_size != 0:
out.fail('[exception] invalid ssh packet (block size)')
sys.exit(1)
self.ensure_read(payload_length)
if sshv == 1:
payload = self.read(payload_length - 4)
header.write(payload)
crc = self.read_int()
header.write_int(crc)
else:
payload = self.read(payload_length)
header.write(payload)
packet_type = ord(payload[0:1])
if sshv == 1:
rcrc = SSH1.crc32(padding + payload)
if crc != rcrc:
out.fail('[exception] packet checksum CRC32 mismatch.')
sys.exit(1)
else:
self.ensure_read(padding_length)
padding = self.read(padding_length)
payload = payload[1:]
return packet_type, payload
except SSH.Socket.InsufficientReadException as ex:
if ex.args[0] is None:
header.write(self.read(self.unread_len))
e = header.write_flush().strip()
else:
e = ex.args[0]
return (-1, e)
def send_packet(self):
payload = self.write_flush()
padding = -(len(payload) + 5) % 8
if padding < 4:
padding += 8
plen = len(payload) + padding + 1
pad_bytes = b'\x00' * padding
data = struct.pack('>Ib', plen, padding) + payload + pad_bytes
return self.send(data)
def __del__(self):
self.__cleanup()
def __exit__(self, ex_type, ex_value, tb):
self.__cleanup()
def __cleanup(self):
try:
self.__sock.shutdown(socket.SHUT_RDWR)
self.__sock.close()
except:
pass
class KexDH(object):
def __init__(self, alg, g, p):
self.__alg = alg
self.__g = g
self.__p = p
self.__q = (self.__p - 1) // 2
self.__x = None
def send_init(self, s):
r = random.SystemRandom()
self.__x = r.randrange(2, self.__q)
self.__e = pow(self.__g, self.__x, self.__p)
s.write_byte(SSH.Protocol.MSG_KEXDH_INIT)
s.write_mpint2(self.__e)
s.send_packet()
class KexGroup1(KexDH):
def __init__(self):
# rfc2409: second oakley group
p = int('ffffffffffffffffc90fdaa22168c234c4c6628b80dc1cd129024e088a67'
'cc74020bbea63b139b22514a08798e3404ddef9519b3cd3a431b302b0a6d'
'f25f14374fe1356d6d51c245e485b576625e7ec6f44c42e9a637ed6b0bff'
'5cb6f406b7edee386bfb5a899fa5ae9f24117c4b1fe649286651ece65381'
'ffffffffffffffff', 16)
super(KexGroup1, self).__init__('sha1', 2, p)
class KexGroup14(KexDH):
def __init__(self):
# rfc3526: 2048-bit modp group
p = int('ffffffffffffffffc90fdaa22168c234c4c6628b80dc1cd129024e088a67'
'cc74020bbea63b139b22514a08798e3404ddef9519b3cd3a431b302b0a6d'
'f25f14374fe1356d6d51c245e485b576625e7ec6f44c42e9a637ed6b0bff'
'5cb6f406b7edee386bfb5a899fa5ae9f24117c4b1fe649286651ece45b3d'
'c2007cb8a163bf0598da48361c55d39a69163fa8fd24cf5f83655d23dca3'
'ad961c62f356208552bb9ed529077096966d670c354e4abc9804f1746c08'
'ca18217c32905e462e36ce3be39e772c180e86039b2783a2ec07a28fb5c5'
'5df06f4c52c9de2bcbf6955817183995497cea956ae515d2261898fa0510'
'15728e5a8aacaa68ffffffffffffffff', 16)
super(KexGroup14, self).__init__('sha1', 2, p)
class KexDB(object):
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'
FAIL_OPENSSH70_LOGJAM = 'disabled (in client) since OpenSSH 7.0, logjam attack'
INFO_OPENSSH69_CHACHA = 'default cipher since OpenSSH 6.9.'
FAIL_OPENSSH67_UNSAFE = 'removed (in server) since OpenSSH 6.7, unsafe algorithm'
FAIL_OPENSSH61_REMOVE = 'removed since OpenSSH 6.1, removed from specification'
FAIL_OPENSSH31_REMOVE = 'removed since OpenSSH 3.1'
FAIL_DBEAR67_DISABLED = 'disabled since Dropbear SSH 2015.67'
FAIL_DBEAR53_DISABLED = 'disabled since Dropbear SSH 0.53'
FAIL_PLAINTEXT = 'no encryption/integrity'
WARN_CURVES_WEAK = 'using weak elliptic curves'
WARN_RNDSIG_KEY = 'using weak random number generator could reveal the key'
WARN_MODULUS_SIZE = 'using small 1024-bit modulus'
WARN_MODULUS_CUSTOM = 'using custom size modulus (possibly weak)'
WARN_HASH_WEAK = 'using weak hashing algorithm'
WARN_CIPHER_MODE = 'using weak cipher mode'
WARN_BLOCK_SIZE = 'using small 64-bit block size'
WARN_CIPHER_WEAK = 'using weak cipher'
WARN_ENCRYPT_AND_MAC = 'using encrypt-and-MAC mode'
WARN_TAG_SIZE = 'using small 64-bit tag size'
ALGORITHMS = {
'kex': {
'diffie-hellman-group1-sha1': [['2.3.0,d0.28,l10.2', '6.6', '6.9'], [FAIL_OPENSSH67_UNSAFE, FAIL_OPENSSH70_LOGJAM], [WARN_MODULUS_SIZE, WARN_HASH_WEAK]],
'diffie-hellman-group14-sha1': [['3.9,d0.53,l10.6.0'], [], [WARN_HASH_WEAK]],
'diffie-hellman-group14-sha256': [['7.3,d2016.73']],
'diffie-hellman-group16-sha512': [['7.3,d2016.73']],
'diffie-hellman-group18-sha512': [['7.3']],
'diffie-hellman-group-exchange-sha1': [['2.3.0', '6.6', None], [FAIL_OPENSSH67_UNSAFE], [WARN_HASH_WEAK]],
'diffie-hellman-group-exchange-sha256': [['4.4'], [], [WARN_MODULUS_CUSTOM]],
'ecdh-sha2-nistp256': [['5.7,d2013.62,l10.6.0'], [WARN_CURVES_WEAK]],
'ecdh-sha2-nistp384': [['5.7,d2013.62'], [WARN_CURVES_WEAK]],
'ecdh-sha2-nistp521': [['5.7,d2013.62'], [WARN_CURVES_WEAK]],
'curve25519-sha256@libssh.org': [['6.5,d2013.62,l10.6.0']],
'kexguess2@matt.ucc.asn.au': [['d2013.57']],
},
'key': {
'rsa-sha2-256': [['7.2']],
'rsa-sha2-512': [['7.2']],
'ssh-ed25519': [['6.5,l10.7.0']],
'ssh-ed25519-cert-v01@openssh.com': [['6.5']],
'ssh-rsa': [['2.5.0,d0.28,l10.2']],
'ssh-dss': [['2.1.0,d0.28,l10.2', '6.9'], [FAIL_OPENSSH70_WEAK], [WARN_MODULUS_SIZE, WARN_RNDSIG_KEY]],
'ecdsa-sha2-nistp256': [['5.7,d2013.62,l10.6.4'], [WARN_CURVES_WEAK], [WARN_RNDSIG_KEY]],
'ecdsa-sha2-nistp384': [['5.7,d2013.62,l10.6.4'], [WARN_CURVES_WEAK], [WARN_RNDSIG_KEY]],
'ecdsa-sha2-nistp521': [['5.7,d2013.62,l10.6.4'], [WARN_CURVES_WEAK], [WARN_RNDSIG_KEY]],
'ssh-rsa-cert-v00@openssh.com': [['5.4', '6.9'], [FAIL_OPENSSH70_LEGACY], []],
'ssh-dss-cert-v00@openssh.com': [['5.4', '6.9'], [FAIL_OPENSSH70_LEGACY], [WARN_MODULUS_SIZE, WARN_RNDSIG_KEY]],
'ssh-rsa-cert-v01@openssh.com': [['5.6']],
'ssh-dss-cert-v01@openssh.com': [['5.6', '6.9'], [FAIL_OPENSSH70_WEAK], [WARN_MODULUS_SIZE, WARN_RNDSIG_KEY]],
'ecdsa-sha2-nistp256-cert-v01@openssh.com': [['5.7'], [WARN_CURVES_WEAK], [WARN_RNDSIG_KEY]],
'ecdsa-sha2-nistp384-cert-v01@openssh.com': [['5.7'], [WARN_CURVES_WEAK], [WARN_RNDSIG_KEY]],
'ecdsa-sha2-nistp521-cert-v01@openssh.com': [['5.7'], [WARN_CURVES_WEAK], [WARN_RNDSIG_KEY]],
},
'enc': {
'none': [['1.2.2,d2013.56,l10.2'], [FAIL_PLAINTEXT]],
'3des-cbc': [['1.2.2,d0.28,l10.2', '6.6', None], [FAIL_OPENSSH67_UNSAFE], [WARN_CIPHER_WEAK, WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
'3des-ctr': [['d0.52']],
'blowfish-cbc': [['1.2.2,d0.28,l10.2', '6.6,d0.52', '7.1,d0.52'], [FAIL_OPENSSH67_UNSAFE, FAIL_DBEAR53_DISABLED], [WARN_OPENSSH72_LEGACY, WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
'twofish-cbc': [['d0.28', 'd2014.66'], [FAIL_DBEAR67_DISABLED], [WARN_CIPHER_MODE]],
'twofish128-cbc': [['d0.47', 'd2014.66'], [FAIL_DBEAR67_DISABLED], [WARN_CIPHER_MODE]],
'twofish256-cbc': [['d0.47', 'd2014.66'], [FAIL_DBEAR67_DISABLED], [WARN_CIPHER_MODE]],
'twofish128-ctr': [['d2015.68']],
'twofish256-ctr': [['d2015.68']],
'cast128-cbc': [['2.1.0', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
'arcfour': [['2.1.0', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_CIPHER_WEAK]],
'arcfour128': [['4.2', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_CIPHER_WEAK]],
'arcfour256': [['4.2', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_CIPHER_WEAK]],
'aes128-cbc': [['2.3.0,d0.28,l10.2', '6.6', None], [FAIL_OPENSSH67_UNSAFE], [WARN_CIPHER_MODE]],
'aes192-cbc': [['2.3.0,l10.2', '6.6', None], [FAIL_OPENSSH67_UNSAFE], [WARN_CIPHER_MODE]],
'aes256-cbc': [['2.3.0,d0.47,l10.2', '6.6', None], [FAIL_OPENSSH67_UNSAFE], [WARN_CIPHER_MODE]],
'rijndael128-cbc': [['2.3.0', '3.0.2'], [FAIL_OPENSSH31_REMOVE], [WARN_CIPHER_MODE]],
'rijndael192-cbc': [['2.3.0', '3.0.2'], [FAIL_OPENSSH31_REMOVE], [WARN_CIPHER_MODE]],
'rijndael256-cbc': [['2.3.0', '3.0.2'], [FAIL_OPENSSH31_REMOVE], [WARN_CIPHER_MODE]],
'rijndael-cbc@lysator.liu.se': [['2.3.0', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_CIPHER_MODE]],
'aes128-ctr': [['3.7,d0.52,l10.4.1']],
'aes192-ctr': [['3.7,l10.4.1']],
'aes256-ctr': [['3.7,d0.52,l10.4.1']],
'aes128-gcm@openssh.com': [['6.2']],
'aes256-gcm@openssh.com': [['6.2']],
'chacha20-poly1305@openssh.com': [['6.5'], [], [], [INFO_OPENSSH69_CHACHA]],
},
'mac': {
'none': [['d2013.56'], [FAIL_PLAINTEXT]],
'hmac-sha1': [['2.1.0,d0.28,l10.2'], [], [WARN_ENCRYPT_AND_MAC, WARN_HASH_WEAK]],
'hmac-sha1-96': [['2.5.0,d0.47', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_ENCRYPT_AND_MAC, WARN_HASH_WEAK]],
'hmac-sha2-256': [['5.9,d2013.56,l10.7.0'], [], [WARN_ENCRYPT_AND_MAC]],
'hmac-sha2-256-96': [['5.9', '6.0'], [FAIL_OPENSSH61_REMOVE], [WARN_ENCRYPT_AND_MAC]],
'hmac-sha2-512': [['5.9,d2013.56,l10.7.0'], [], [WARN_ENCRYPT_AND_MAC]],
'hmac-sha2-512-96': [['5.9', '6.0'], [FAIL_OPENSSH61_REMOVE], [WARN_ENCRYPT_AND_MAC]],
'hmac-md5': [['2.1.0,d0.28', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_ENCRYPT_AND_MAC, WARN_HASH_WEAK]],
'hmac-md5-96': [['2.5.0', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_ENCRYPT_AND_MAC, WARN_HASH_WEAK]],
'hmac-ripemd160': [['2.5.0', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_ENCRYPT_AND_MAC]],
'hmac-ripemd160@openssh.com': [['2.1.0', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_ENCRYPT_AND_MAC]],
'umac-64@openssh.com': [['4.7'], [], [WARN_ENCRYPT_AND_MAC, WARN_TAG_SIZE]],
'umac-128@openssh.com': [['6.2'], [], [WARN_ENCRYPT_AND_MAC]],
'hmac-sha1-etm@openssh.com': [['6.2'], [], [WARN_HASH_WEAK]],
'hmac-sha1-96-etm@openssh.com': [['6.2', '6.6', None], [FAIL_OPENSSH67_UNSAFE], [WARN_HASH_WEAK]],
'hmac-sha2-256-etm@openssh.com': [['6.2']],
'hmac-sha2-512-etm@openssh.com': [['6.2']],
'hmac-md5-etm@openssh.com': [['6.2', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_HASH_WEAK]],
'hmac-md5-96-etm@openssh.com': [['6.2', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY, WARN_HASH_WEAK]],
'hmac-ripemd160-etm@openssh.com': [['6.2', '6.6', '7.1'], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH72_LEGACY]],
'umac-64-etm@openssh.com': [['6.2'], [], [WARN_TAG_SIZE]],
'umac-128-etm@openssh.com': [['6.2']],
}
}
def get_ssh_version(version_desc):
if version_desc.startswith('d'):
return (SSH.Product.DropbearSSH, version_desc[1:])
elif version_desc.startswith('l1'):
return (SSH.Product.LibSSH, version_desc[2:])
else:
return (SSH.Product.OpenSSH, version_desc)
def get_alg_timeframe(alg_desc, for_server=True, result={}):
versions = alg_desc[0]
vlen = len(versions)
for i in range(3):
if i > vlen - 1:
if i == 2 and vlen > 1:
cversions = versions[1]
else:
continue
else:
cversions = versions[i]
if cversions is None:
continue
for v in cversions.split(','):
ssh_prefix, ssh_version = get_ssh_version(v)
if not ssh_version:
continue
if ssh_version.endswith('C'):
if for_server:
continue
ssh_version = ssh_version[:-1]
if ssh_prefix not in result:
result[ssh_prefix] = [None, None, None]
prev, push = result[ssh_prefix][i], False
if prev is None:
push = True
elif i == 0 and prev < ssh_version:
push = True
elif i > 0 and prev > ssh_version:
push = True
if push:
result[ssh_prefix][i] = ssh_version
return result
def get_ssh_timeframe(alg_pairs, for_server=True):
timeframe = {}
for alg_pair in alg_pairs:
sshv, alg_db = alg_pair[0]
alg_sets = alg_pair[1:]
for alg_set in alg_sets:
alg_type, alg_list = alg_set
for alg_name in alg_list:
alg_desc = alg_db[alg_type].get(alg_name)
if alg_desc is None:
continue
timeframe = get_alg_timeframe(alg_desc, for_server, timeframe)
return timeframe
def get_alg_since_text(alg_desc):
tv = []
versions = alg_desc[0]
if len(versions) == 0 or versions[0] is None:
return None
for v in versions[0].split(','):
ssh_prefix, ssh_version = get_ssh_version(v)
if not ssh_version:
continue
if ssh_prefix in [SSH.Product.LibSSH]:
continue
if ssh_version.endswith('C'):
ssh_version = '{0} (client only)'.format(ssh_version[:-1])
tv.append('{0} {1}'.format(ssh_prefix, ssh_version))
if len(tv) == 0:
return None
return 'available since ' + ', '.join(tv).rstrip(', ')
def get_alg_pairs(kex, pkm):
alg_pairs = []
if pkm is not None:
alg_pairs.append(((1, SSH1.KexDB.ALGORITHMS),
('key', ['ssh-rsa1']),
('enc', pkm.supported_ciphers),
('aut', pkm.supported_authentications)))
if kex is not None:
alg_pairs.append(((2, KexDB.ALGORITHMS),
('kex', kex.kex_algorithms),
('key', kex.key_algorithms),
('enc', kex.server.encryption),
('mac', kex.server.mac)))
return alg_pairs
def get_alg_recommendations(software, kex, pkm, for_server=True):
alg_pairs = get_alg_pairs(kex, pkm)
vproducts = [SSH.Product.OpenSSH,
SSH.Product.DropbearSSH,
SSH.Product.LibSSH]
if software is not None:
if software.product not in vproducts:
software = None
if software is None:
ssh_timeframe = get_ssh_timeframe(alg_pairs, for_server)
for product in vproducts:
if product not in ssh_timeframe:
continue
version = ssh_timeframe[product][0]
if version is not None:
software = SSH.Software(None, product, version, None, None)
break
rec = {'.software': software}
if software is None:
return rec
for alg_pair in alg_pairs:
sshv, alg_db = alg_pair[0]
alg_sets = alg_pair[1:]
rec[sshv] = {}
for alg_set in alg_sets:
alg_type, alg_list = alg_set
if alg_type == 'aut':
continue
rec[sshv][alg_type] = {'add': [], 'del': {}}
for n, alg_desc in alg_db[alg_type].items():
if alg_type == 'key' and '-cert-' in n:
continue
versions = alg_desc[0]
if len(versions) == 0 or versions[0] is None:
continue
matches = False
for v in versions[0].split(','):
ssh_prefix, ssh_version = get_ssh_version(v)
if not ssh_version:
continue
if ssh_prefix != software.product:
continue
if ssh_version.endswith('C'):
if for_server:
continue
ssh_version = ssh_version[:-1]
if software.compare_version(ssh_version) < 0:
continue
matches = True
break
if not matches:
continue
adl, faults = len(alg_desc), 0
for i in range(1, 3):
if not adl > i:
continue
fc = len(alg_desc[i])
if fc > 0:
faults += pow(10, 2 - i) * fc
if n not in alg_list:
if faults > 0:
continue
rec[sshv][alg_type]['add'].append(n)
else:
if faults == 0:
continue
if n == 'diffie-hellman-group-exchange-sha256':
if software.compare_version('7.3') < 0:
continue
rec[sshv][alg_type]['del'][n] = faults
add_count = len(rec[sshv][alg_type]['add'])
del_count = len(rec[sshv][alg_type]['del'])
new_alg_count = len(alg_list) + add_count - del_count
if new_alg_count < 1 and del_count > 0:
mf, new_del = min(rec[sshv][alg_type]['del'].values()), {}
for k, v in rec[sshv][alg_type]['del'].items():
if v != mf:
new_del[k] = v
if del_count != len(new_del):
rec[sshv][alg_type]['del'] = new_del
new_alg_count += del_count - len(new_del)
if new_alg_count < 1:
del rec[sshv][alg_type]
else:
if add_count == 0:
del rec[sshv][alg_type]['add']
if del_count == 0:
del rec[sshv][alg_type]['del']
if len(rec[sshv][alg_type]) == 0:
del rec[sshv][alg_type]
if len(rec[sshv]) == 0:
del rec[sshv]
return rec
def output_algorithms(title, alg_db, alg_type, algorithms, maxlen=0):
with OutputBuffer() as obuf:
for algorithm in algorithms:
output_algorithm(alg_db, alg_type, algorithm, maxlen)
if len(obuf) > 0:
out.head('# ' + title)
obuf.flush()
out.sep()
def output_algorithm(alg_db, alg_type, alg_name, alg_max_len=0):
prefix = '(' + alg_type + ') '
if alg_max_len == 0:
alg_max_len = len(alg_name)
padding = '' if out.batch else ' ' * (alg_max_len - len(alg_name))
texts = []
if len(alg_name.strip()) == 0:
return
if alg_name in alg_db[alg_type]:
alg_desc = alg_db[alg_type][alg_name]
ldesc = len(alg_desc)
for idx, level in enumerate(['fail', 'warn', 'info']):
if level == 'info':
since_text = get_alg_since_text(alg_desc)
if since_text:
texts.append((level, since_text))
idx = idx + 1
if ldesc > idx:
for t in alg_desc[idx]:
texts.append((level, t))
if len(texts) == 0:
texts.append(('info', ''))
else:
texts.append(('warn', 'unknown algorithm'))
first = True
for (level, text) in texts:
f = getattr(out, level)
text = '[' + level + '] ' + text
if first:
if first and level == 'info':
f = out.good
f(prefix + alg_name + padding + ' -- ' + text)
first = False
else:
if out.verbose:
f(prefix + alg_name + padding + ' -- ' + text)
else:
f(' ' * len(prefix + alg_name) + padding + ' `- ' + text)
def output_compatibility(kex, pkm, for_server=True):
alg_pairs = get_alg_pairs(kex, pkm)
ssh_timeframe = get_ssh_timeframe(alg_pairs, for_server)
vp = 1 if for_server else 2
comp_text = []
for sshd_name in [SSH.Product.OpenSSH, SSH.Product.DropbearSSH]:
if sshd_name not in ssh_timeframe:
continue
v = ssh_timeframe[sshd_name]
if v[vp] is None:
comp_text.append('{0} {1}+'.format(sshd_name, v[0]))
elif v[0] == v[vp]:
comp_text.append('{0} {1}'.format(sshd_name, v[0]))
else:
if v[vp] < v[0]:
tfmt = '{0} {1}+ (some functionality from {2})'
else:
tfmt = '{0} {1}-{2}'
comp_text.append(tfmt.format(sshd_name, v[0], v[vp]))
if len(comp_text) > 0:
out.good('(gen) compatibility: ' + ', '.join(comp_text))
def output_security_sub(sub, software, padlen):
secdb = SSH.Security.CVE if sub == 'cve' else SSH.Security.TXT
if software is None or software.product not in secdb:
return
for line in secdb[software.product]:
vfrom, vtill = line[0:2]
if not software.between_versions(vfrom, vtill):
continue
target, name = line[2:4]
is_server, is_client = target & 1 == 1, target & 2 == 2
is_local = target & 4 == 4
if not is_server:
continue
p = '' if out.batch else ' ' * (padlen - len(name))
if sub == 'cve':
cvss, descr = line[4:6]
out.fail('(cve) {0}{1} -- ({2}) {3}'.format(name, p, cvss, descr))
else:
descr = line[4]
out.fail('(sec) {0}{1} -- {2}'.format(name, p, descr))
def output_security(banner, padlen):
with OutputBuffer() as obuf:
if banner:
software = SSH.Software.parse(banner)
output_security_sub('cve', software, padlen)
output_security_sub('txt', software, padlen)
if len(obuf) > 0:
out.head('# security')
obuf.flush()
out.sep()
def output_fingerprint(kex, pkm, sha256=True, padlen=0):
with OutputBuffer() as obuf:
fps = []
if pkm is not None:
name = 'ssh-rsa1'
fp = SSH.Fingerprint(pkm.host_key_fingerprint_data)
bits = pkm.host_key_bits
fps.append((name, fp, bits))
for fpp in fps:
name, fp, bits = fpp
fp = fp.sha256 if sha256 else fp.md5
p = '' if out.batch else ' ' * (padlen - len(name))
out.good('(fin) {0}{1} -- {2} {3}'.format(name, p, bits, fp))
if len(obuf) > 0:
out.head('# fingerprints')
obuf.flush()
out.sep()
def output_recommendations(software, kex, pkm, padlen=0):
for_server = True
with OutputBuffer() as obuf:
alg_rec = get_alg_recommendations(software, kex, pkm, for_server)
software = alg_rec['.software']
for sshv in range(2, 0, -1):
if sshv not in alg_rec:
continue
for alg_type in ['kex', 'key', 'enc', 'mac']:
if alg_type not in alg_rec[sshv]:
continue
for action in ['del', 'add']:
if action not in alg_rec[sshv][alg_type]:
continue
for name in alg_rec[sshv][alg_type][action]:
p = '' if out.batch else ' ' * (padlen - len(name))
if action == 'del':
an, sg, fn = 'remove', '-', out.warn
if alg_rec[sshv][alg_type][action][name] >= 10:
fn = out.fail
else:
an, sg, fn = 'append', '+', out.good
b = '(SSH{0})'.format(sshv) if sshv == 1 else ''
fm = '(rec) {0}{1}{2}-- {3} algorithm to {4} {5}'
fn(fm.format(sg, name, p, alg_type, an, b))
if len(obuf) > 0:
title = '(for {0})'.format(software.display(False)) if software else ''
out.head('# algorithm recommendations {0}'.format(title))
obuf.flush()
out.sep()
def output(banner, header, kex=None, pkm=None):
sshv = 1 if pkm else 2
with OutputBuffer() as obuf:
if len(header) > 0:
out.info('(gen) header: ' + '\n'.join(header))
if banner is not None:
out.good('(gen) banner: {0}'.format(banner))
if sshv == 1 or banner.protocol[0] == 1:
out.fail('(gen) protocol SSH1 enabled')
software = SSH.Software.parse(banner)
if software is not None:
out.good('(gen) software: {0}'.format(software))
else:
software = None
output_compatibility(kex, pkm)
if kex is not None:
compressions = [x for x in kex.server.compression if x != 'none']
if len(compressions) > 0:
cmptxt = 'enabled ({0})'.format(', '.join(compressions))
else:
cmptxt = 'disabled'
out.good('(gen) compression: {0}'.format(cmptxt))
if len(obuf) > 0:
out.head('# general')
obuf.flush()
out.sep()
ml, maxlen = lambda l: max(len(i) for i in l), 0
if pkm is not None:
maxlen = max(ml(pkm.supported_ciphers),
ml(pkm.supported_authentications),
maxlen)
if kex is not None:
maxlen = max(ml(kex.kex_algorithms),
ml(kex.key_algorithms),
ml(kex.server.encryption),
ml(kex.server.mac),
maxlen)
maxlen += 1
output_security(banner, maxlen)
if pkm is not None:
adb = SSH1.KexDB.ALGORITHMS
ciphers = pkm.supported_ciphers
auths = pkm.supported_authentications
title, atype = 'SSH1 host-key algorithms', 'key'
output_algorithms(title, adb, atype, ['ssh-rsa1'], maxlen)
title, atype = 'SSH1 encryption algorithms (ciphers)', 'enc'
output_algorithms(title, adb, atype, ciphers, maxlen)
title, atype = 'SSH1 authentication types', 'aut'
output_algorithms(title, adb, atype, auths, maxlen)
if kex is not None:
adb = KexDB.ALGORITHMS
title, atype = 'key exchange algorithms', 'kex'
output_algorithms(title, adb, atype, kex.kex_algorithms, maxlen)
title, atype = 'host-key algorithms', 'key'
output_algorithms(title, adb, atype, kex.key_algorithms, maxlen)
title, atype = 'encryption algorithms (ciphers)', 'enc'
output_algorithms(title, adb, atype, kex.server.encryption, maxlen)
title, atype = 'message authentication code algorithms', 'mac'
output_algorithms(title, adb, atype, kex.server.mac, maxlen)
output_recommendations(software, kex, pkm, maxlen)
output_fingerprint(kex, pkm, True, maxlen)
class Utils(object):
PY2 = sys.version_info[0] == 2
@classmethod
def wrap(cls):
o = cls()
if cls.PY2:
import StringIO
o.StringIO = o.BytesIO = StringIO.StringIO
else:
o.StringIO, o.BytesIO = io.StringIO, io.BytesIO
return o
@staticmethod
def parse_int(v):
try:
return int(v)
except:
return 0
def audit(conf, sshv=None):
out.batch = conf.batch
out.colors = conf.colors
out.verbose = conf.verbose
out.minlevel = conf.minlevel
s = SSH.Socket(conf.host, conf.port)
if sshv is None:
sshv = 2 if conf.ssh2 else 1
err = None
banner, header = s.get_banner(sshv)
if banner is None:
err = '[exception] did not receive banner.'
if err is None:
packet_type, payload = s.read_packet(sshv)
if packet_type < 0:
payload = str(payload).decode('utf-8')
if payload == u'Protocol major versions differ.':
if sshv == 2 and conf.ssh1:
audit(conf, 1)
return
err = '[exception] error reading packet ({0})'.format(payload)
else:
if sshv == 1 and packet_type != SSH.Protocol.SMSG_PUBLIC_KEY:
err = ('SMSG_PUBLIC_KEY', SSH.Protocol.SMSG_PUBLIC_KEY)
elif sshv == 2 and packet_type != SSH.Protocol.MSG_KEXINIT:
err = ('MSG_KEXINIT', SSH.Protocol.MSG_KEXINIT)
if err is not None:
fmt = '[exception] did not receive {0} ({1}), ' + \
'instead received unknown message ({2})'
err = fmt.format(err[0], err[1], packet_type)
if err:
output(banner, header)
out.fail(err)
sys.exit(1)
if sshv == 1:
pkm = SSH1.PublicKeyMessage.parse(payload)
output(banner, header, pkm=pkm)
elif sshv == 2:
kex = SSH2.Kex.parse(payload)
output(banner, header, kex=kex)
utils = Utils.wrap()
out = Output()
if __name__ == '__main__':
conf = AuditConf.from_cmdline(sys.argv[1:], usage)
audit(conf)
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