#!/usr/bin/env python3 """ The MIT License (MIT) Copyright (C) 2017-2020 Joe Testa (jtesta@positronsecurity.com) Copyright (C) 2017 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 datetime import date import base64 import binascii import errno import getopt import hashlib import io import json import ipaddress import os import random import re import select import socket import struct import sys import traceback # pylint: disable=unused-import from typing import Dict, List, Set, Sequence, Tuple, Iterable from typing import Callable, Optional, Union, Any VERSION = 'v2.2.1-dev' SSH_HEADER = 'SSH-{0}-OpenSSH_8.0' # SSH software to impersonate # The program return values corresponding to failure(s) encountered, warning(s) encountered, connection errors, and no problems found, respectively. PROGRAM_RETVAL_FAILURE = 3 PROGRAM_RETVAL_WARNING = 2 PROGRAM_RETVAL_CONNECTION_ERROR = 1 PROGRAM_RETVAL_GOOD = 0 PROGRAM_RETVAL_UNKNOWN_ERROR = -1 try: # pragma: nocover from colorama import init as colorama_init colorama_init(strip=False) # pragma: nocover except ImportError: # pragma: nocover pass def usage(err: Optional[str] = None) -> None: uout = Output() p = os.path.basename(sys.argv[0]) uout.head('# {} {}, https://github.com/jtesta/ssh-audit\n'.format(p, VERSION)) if err is not None and len(err) > 0: uout.fail('\n' + err) uout.info('usage: {0} [-h1246ptbcPjlnv] \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 to connect') uout.info(' -t, --timeout= timeout (in seconds) for connection and reading\n (default: 5)') uout.info(' -T, --targets= a file containing a list of target hosts (one\n per line)') uout.info('') uout.info(' -b, --batch batch output') uout.info(' -c, --client-audit starts a server on port 2222 to audit client\n software config (use -p to change port;\n use -t to change timeout)') uout.info(' -M, --make-policy= creates a policy based on the target server\n (i.e.: the target server has the ideal\n configuration that other servers should\n adhere to)') uout.info(' -P, --policy= run a policy test using the specified policy') uout.info('') uout.info(' -j, --json JSON output') uout.info(' -l, --level= minimum output level (info|warn|fail)') uout.info(' -n, --no-colors disable colors') uout.info(' -v, --verbose verbose output') uout.sep() sys.exit(1) # Validates policy files and performs policy testing class Policy: def __init__(self, policy_file: Optional[str] = None, policy_data: Optional[str] = None) -> None: self._name = None # type: Optional[str] self._version = None # type: Optional[str] self._banner = None # type: Optional[str] self._compressions = None # type: Optional[List[str]] self._host_keys = None # type: Optional[List[str]] self._kex = None # type: Optional[List[str]] self._ciphers = None # type: Optional[List[str]] self._macs = None # type: Optional[List[str]] self._hostkey_sizes = None # type: Optional[Dict[str, int]] self._cakey_sizes = None # type: Optional[Dict[str, int]] self._dh_modulus_sizes = None # type: Optional[Dict[str, int]] if (policy_file is None) and (policy_data is None): raise RuntimeError('policy_file and policy_data must not both be None.') elif (policy_file is not None) and (policy_data is not None): raise RuntimeError('policy_file and policy_data must not both be specified.') if policy_file is not None: with open(policy_file, "r") as f: policy_data = f.read() lines = [] if policy_data is not None: lines = policy_data.split("\n") for line in lines: line = line.strip() if (len(line) == 0) or line.startswith('#'): continue key = None val = None try: key, val = line.split('=') except ValueError: raise ValueError("could not parse line: %s" % line) key = key.strip() val = val.strip() if key not in ['name', 'version', 'banner', 'compressions', 'host keys', 'key exchanges', 'ciphers', 'macs'] and not key.startswith('hostkey_size_') and not key.startswith('cakey_size_') and not key.startswith('dh_modulus_size_'): raise ValueError("invalid field found in policy: %s" % line) if key in ['name', 'banner']: # If the banner value is blank, set it to "" so that the code below handles it. if len(val) < 2: val = "\"\"" if (val[0] != '"') or (val[-1] != '"'): raise ValueError('the value for the %s field must be enclosed in quotes: %s' % (key, val)) # Remove the surrounding quotes, and unescape quotes & newlines. val = val[1:-1]. replace("\\\"", "\"").replace("\\n", "\n") if key == 'name': self._name = val elif key == 'banner': self._banner = val elif key == 'version': self._version = val elif key in ['compressions', 'host keys', 'key exchanges', 'ciphers', 'macs']: try: algs = val.split(',') except ValueError: # If the value has no commas, then set the algorithm list to just the value. algs = [val] # Strip whitespace in each algorithm name. algs = [alg.strip() for alg in algs] if key == 'compressions': self._compressions = algs elif key == 'host keys': self._host_keys = algs elif key == 'key exchanges': self._kex = algs elif key == 'ciphers': self._ciphers = algs elif key == 'macs': self._macs = algs elif key.startswith('hostkey_size_'): hostkey_type = key[13:] if self._hostkey_sizes is None: self._hostkey_sizes = {} self._hostkey_sizes[hostkey_type] = int(val) elif key.startswith('cakey_size_'): cakey_type = key[11:] if self._cakey_sizes is None: self._cakey_sizes = {} self._cakey_sizes[cakey_type] = int(val) elif key.startswith('dh_modulus_size_'): dh_modulus_type = key[16:] if self._dh_modulus_sizes is None: self._dh_modulus_sizes = {} self._dh_modulus_sizes[dh_modulus_type] = int(val) if self._name is None: raise ValueError('The policy does not have a name field.') if self._version is None: raise ValueError('The policy does not have a version field.') @staticmethod def create(host: str, banner: Optional['SSH.Banner'], kex: Optional['SSH2.Kex']) -> str: '''Creates a policy based on a server configuration. Returns a string.''' today = date.today().strftime('%Y/%m/%d') compressions = None host_keys = None kex_algs = None ciphers = None macs = None rsa_hostkey_sizes_str = '' rsa_cakey_sizes_str = '' dh_modulus_sizes_str = '' if kex is not None: if kex.server.compression is not None: compressions = ', '.join(kex.server.compression) if kex.key_algorithms is not None: host_keys = ', '.join(kex.key_algorithms) if kex.kex_algorithms is not None: kex_algs = ', '.join(kex.kex_algorithms) if kex.server.encryption is not None: ciphers = ', '.join(kex.server.encryption) if kex.server.mac is not None: macs = ', '.join(kex.server.mac) if kex.rsa_key_sizes(): rsa_key_sizes_dict = kex.rsa_key_sizes() for host_key_type in sorted(rsa_key_sizes_dict): hostkey_size, cakey_size = rsa_key_sizes_dict[host_key_type] rsa_hostkey_sizes_str = "%shostkey_size_%s = %d\n" % (rsa_hostkey_sizes_str, host_key_type, hostkey_size) if cakey_size != -1: rsa_cakey_sizes_str = "%scakey_size_%s = %d\n" % (rsa_cakey_sizes_str, host_key_type, cakey_size) if len(rsa_hostkey_sizes_str) > 0: rsa_hostkey_sizes_str = "\n# RSA host key sizes.\n%s" % rsa_hostkey_sizes_str if len(rsa_cakey_sizes_str) > 0: rsa_cakey_sizes_str = "\n# RSA CA key sizes.\n%s" % rsa_cakey_sizes_str if kex.dh_modulus_sizes(): dh_modulus_sizes_dict = kex.dh_modulus_sizes() for gex_type in sorted(dh_modulus_sizes_dict): modulus_size, _ = dh_modulus_sizes_dict[gex_type] dh_modulus_sizes_str = "%sdh_modulus_size_%s = %d\n" % (dh_modulus_sizes_str, gex_type, modulus_size) if len(dh_modulus_sizes_str) > 0: dh_modulus_sizes_str = "\n# Group exchange DH modulus sizes.\n%s" % dh_modulus_sizes_str policy_data = '''# # Custom policy based on %s (created on %s) # # The name of this policy (displayed in the output during scans). Must be in quotes. name = "Custom Policy (based on %s on %s)" # The version of this policy (displayed in the output during scans). Not parsed, and may be any value, including strings. version = 1 # The banner that must match exactly. Commented out to ignore banners, since minor variability in the banner is sometimes normal. # banner = "%s" # The compression options that must match exactly (order matters). Commented out to ignore by default. # compressions = %s %s%s%s # The host key types that must match exactly (order matters). host keys = %s # The key exchange algorithms that must match exactly (order matters). key exchanges = %s # The ciphers that must match exactly (order matters). ciphers = %s # The MACs that must match exactly (order matters). macs = %s ''' % (host, today, host, today, banner, compressions, rsa_hostkey_sizes_str, rsa_cakey_sizes_str, dh_modulus_sizes_str, host_keys, kex_algs, ciphers, macs) return policy_data def evaluate(self, banner: Optional['SSH.Banner'], kex: Optional['SSH2.Kex']) -> Tuple[bool, List[str]]: '''Evaluates a server configuration against this policy. Returns a tuple of a boolean (True if server adheres to policy) and an array of strings that holds error messages.''' ret = True errors = [] banner_str = str(banner) if (self._banner is not None) and (banner_str != self._banner): ret = False errors.append('Banner did not match. Expected: [%s]; Actual: [%s]' % (self._banner, banner_str)) # All subsequent tests require a valid kex, so end here if we don't have one. if kex is None: return ret, errors if (self._compressions is not None) and (kex.server.compression != self._compressions): ret = False errors.append('Compression types did not match. Expected: %s; Actual: %s' % (self._compressions, kex.server.compression)) if (self._host_keys is not None) and (kex.key_algorithms != self._host_keys): ret = False errors.append('Host key types did not match. Expected: %s; Actual: %s' % (self._host_keys, kex.key_algorithms)) if self._hostkey_sizes is not None: hostkey_types = list(self._hostkey_sizes.keys()) hostkey_types.sort() # Sorted to make testing output repeatable. for hostkey_type in hostkey_types: expected_hostkey_size = self._hostkey_sizes[hostkey_type] if hostkey_type in kex.rsa_key_sizes(): actual_hostkey_size, actual_cakey_size = kex.rsa_key_sizes()[hostkey_type] if actual_hostkey_size != expected_hostkey_size: ret = False errors.append('RSA hostkey (%s) sizes did not match. Expected: %d; Actual: %d' % (hostkey_type, expected_hostkey_size, actual_hostkey_size)) if self._cakey_sizes is not None: hostkey_types = list(self._cakey_sizes.keys()) hostkey_types.sort() # Sorted to make testing output repeatable. for hostkey_type in hostkey_types: expected_cakey_size = self._cakey_sizes[hostkey_type] if hostkey_type in kex.rsa_key_sizes(): actual_hostkey_size, actual_cakey_size = kex.rsa_key_sizes()[hostkey_type] if actual_cakey_size != expected_cakey_size: ret = False errors.append('RSA CA key (%s) sizes did not match. Expected: %d; Actual: %d' % (hostkey_type, expected_cakey_size, actual_cakey_size)) if kex.kex_algorithms != self._kex: ret = False errors.append('Key exchanges did not match. Expected: %s; Actual: %s' % (self._kex, kex.kex_algorithms)) if (self._ciphers is not None) and (kex.server.encryption != self._ciphers): ret = False errors.append('Ciphers did not match. Expected: %s; Actual: %s' % (self._ciphers, kex.server.encryption)) if (self._macs is not None) and (kex.server.mac != self._macs): ret = False errors.append('MACs did not match. Expected: %s; Actual: %s' % (self._macs, kex.server.mac)) if self._dh_modulus_sizes is not None: dh_modulus_types = list(self._dh_modulus_sizes.keys()) dh_modulus_types.sort() # Sorted to make testing output repeatable. for dh_modulus_type in dh_modulus_types: expected_dh_modulus_size = self._dh_modulus_sizes[dh_modulus_type] if dh_modulus_type in kex.dh_modulus_sizes(): actual_dh_modulus_size, _ = kex.dh_modulus_sizes()[dh_modulus_type] if expected_dh_modulus_size != actual_dh_modulus_size: ret = False errors.append('Group exchange (%s) modulus sizes did not match. Expected: %d; Actual: %d' % (dh_modulus_type, expected_dh_modulus_size, actual_dh_modulus_size)) return ret, errors def get_name_and_version(self) -> str: '''Returns a string of this Policy's name and version.''' return '%s v%s' % (self._name, self._version) def __str__(self) -> str: undefined = '{undefined}' name = undefined version = undefined banner = undefined compressions_str = undefined host_keys_str = undefined kex_str = undefined ciphers_str = undefined macs_str = undefined if self._name is not None: name = '[%s]' % self._name if self._version is not None: version = '[%s]' % self._version if self._banner is not None: banner = '[%s]' % self._banner if self._compressions is not None: compressions_str = ', '.join(self._compressions) if self._host_keys is not None: host_keys_str = ', '.join(self._host_keys) if self._kex is not None: kex_str = ', '.join(self._kex) if self._ciphers is not None: ciphers_str = ', '.join(self._ciphers) if self._macs is not None: macs_str = ', '.join(self._macs) return "Name: %s\nVersion: %s\nBanner: %s\nCompressions: %s\nHost Keys: %s\nKey Exchanges: %s\nCiphers: %s\nMACs: %s" % (name, version, banner, compressions_str, host_keys_str, kex_str, ciphers_str, macs_str) class AuditConf: # pylint: disable=too-many-instance-attributes def __init__(self, host: str = '', port: int = 22) -> None: self.host = host self.port = port self.ssh1 = True self.ssh2 = True self.batch = False self.client_audit = False self.colors = True self.json = False self.verbose = False self.level = 'info' self.ipvo = () # type: Sequence[int] self.ipv4 = False self.ipv6 = False self.make_policy = False # When True, creates a policy file from an audit scan. self.policy_file = None # type: Optional[str] # File system path to a policy self.policy = None # type: Optional[Policy] # Policy object self.timeout = 5.0 self.timeout_set = False # Set to True when the user explicitly sets it. self.target_file = None # type: Optional[str] self.target_list = [] # type: List[str] def __setattr__(self, name: str, value: Union[str, int, float, bool, Sequence[int]]) -> None: valid = False if name in ['ssh1', 'ssh2', 'batch', 'client_audit', 'colors', 'verbose', 'timeout_set', 'json', 'make_policy']: valid, value = True, bool(value) elif name in ['ipv4', 'ipv6']: valid = False value = bool(value) ipv = 4 if name == 'ipv4' else 6 if value: value = tuple(list(self.ipvo) + [ipv]) else: # pylint: disable=else-if-used if len(self.ipvo) == 0: value = (6,) if ipv == 4 else (4,) else: value = tuple([x for x in self.ipvo if x != ipv]) self.__setattr__('ipvo', value) elif name == 'ipvo': if isinstance(value, (tuple, list)): uniq_value = utils.unique_seq(value) value = tuple([x for x in uniq_value if x in (4, 6)]) 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: raise ValueError('invalid port: {}'.format(value)) value = port elif name in ['level']: if value not in ('info', 'warn', 'fail'): raise ValueError('invalid level: {}'.format(value)) valid = True elif name == 'host': valid = True elif name == 'timeout': value = utils.parse_float(value) if value == -1.0: raise ValueError('invalid timeout: {}'.format(value)) valid = True elif name in ['policy_file', 'policy', 'target_file', 'target_list']: valid = True if valid: object.__setattr__(self, name, value) @classmethod def from_cmdline(cls, args: List[str], usage_cb: Callable[..., None]) -> 'AuditConf': # pylint: disable=too-many-statements # pylint: disable=too-many-branches aconf = cls() try: sopts = 'h1246M:p:P:jbcnvl:t:T:' lopts = ['help', 'ssh1', 'ssh2', 'ipv4', 'ipv6', 'make-policy=', 'port=', 'policy=', 'json', 'batch', 'client-audit', 'no-colors', 'verbose', 'level=', 'timeout=', 'targets='] opts, args = getopt.gnu_getopt(args, sopts, lopts) except getopt.GetoptError as err: usage_cb(str(err)) aconf.ssh1, aconf.ssh2 = False, False host = '' # type: str oport = None # type: Optional[str] port = 0 # type: int for o, a in opts: if o in ('-h', '--help'): usage_cb() elif o in ('-1', '--ssh1'): 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 elif o in ('-c', '--client-audit'): aconf.client_audit = True elif o in ('-n', '--no-colors'): aconf.colors = False elif o in ('-j', '--json'): aconf.json = True elif o in ('-v', '--verbose'): aconf.verbose = True elif o in ('-l', '--level'): if a not in ('info', 'warn', 'fail'): usage_cb('level {} is not valid'.format(a)) aconf.level = a elif o in ('-t', '--timeout'): aconf.timeout = float(a) aconf.timeout_set = True elif o in ('-M', '--make-policy'): aconf.make_policy = True aconf.policy_file = a elif o in ('-P', '--policy'): aconf.policy_file = a elif o in ('-T', '--targets'): aconf.target_file = a if len(args) == 0 and aconf.client_audit is False and aconf.target_file is None: usage_cb() if aconf.client_audit is False and aconf.target_file is None: if oport is not None: host = args[0] else: host, port = Utils.parse_host_and_port(args[0]) if not host and aconf.target_file is None: usage_cb('host is empty') if port == 0 and oport is None: if aconf.client_audit: # The default port to listen on during a client audit is 2222. port = 2222 else: port = 22 if oport is not None: port = utils.parse_int(oport) if port <= 0 or port > 65535: usage_cb('port {} is not valid'.format(oport)) aconf.host = host aconf.port = port if not (aconf.ssh1 or aconf.ssh2): aconf.ssh1, aconf.ssh2 = True, True # If a file containing a list of targets was given, read it. if aconf.target_file is not None: with open(aconf.target_file, 'r') as f: aconf.target_list = f.readlines() # Strip out whitespace from each line in target file. aconf.target_list = [target.strip() for target in aconf.target_list] # If a policy file was provided, validate it. if (aconf.policy_file is not None) and (aconf.make_policy is False): try: aconf.policy = Policy(policy_file=aconf.policy_file) except Exception as e: print("Error while loading policy file: %s: %s" % (str(e), traceback.format_exc())) sys.exit(-1) return aconf class Output: LEVELS = ('info', 'warn', 'fail') # type: Sequence[str] COLORS = {'head': 36, 'good': 32, 'warn': 33, 'fail': 31} def __init__(self) -> None: self.batch = False self.verbose = False self.use_colors = True self.json = False self.__level = 0 self.__colsupport = 'colorama' in sys.modules or os.name == 'posix' @property def level(self) -> str: if self.__level < len(self.LEVELS): return self.LEVELS[self.__level] return 'unknown' @level.setter def level(self, name: str) -> None: self.__level = self.get_level(name) def get_level(self, name: str) -> int: cname = 'info' if name == 'good' else name if cname not in self.LEVELS: return sys.maxsize return self.LEVELS.index(cname) def sep(self) -> None: if not self.batch: print() @property def colors_supported(self) -> bool: return self.__colsupport @staticmethod def _colorized(color: str) -> Callable[[str], None]: return lambda x: print(u'{}{}\033[0m'.format(color, x)) def __getattr__(self, name: str) -> Callable[[str], None]: if name == 'head' and self.batch: return lambda x: None if not self.get_level(name) >= self.__level: return lambda x: None if self.use_colors and self.colors_supported and name in self.COLORS: color = '\033[0;{}m'.format(self.COLORS[name]) return self._colorized(color) else: return lambda x: print(u'{}'.format(x)) class OutputBuffer(List[str]): def __enter__(self) -> 'OutputBuffer': # pylint: disable=attribute-defined-outside-init self.__buf = io.StringIO() self.__stdout = sys.stdout sys.stdout = self.__buf return self def flush(self, sort_lines: bool = False) -> None: # Lines must be sorted in some cases to ensure consistent testing. if sort_lines: self.sort() # pylint: disable=no-member for line in self: # pylint: disable=not-an-iterable print(line) def __exit__(self, *args: Any) -> None: self.extend(self.__buf.getvalue().splitlines()) # pylint: disable=no-member sys.stdout = self.__stdout 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' 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_DEPRECATED_CIPHER = 'deprecated cipher' FAIL_WEAK_CIPHER = 'using weak cipher' FAIL_WEAK_ALGORITHM = 'using weak/obsolete algorithm' FAIL_PLAINTEXT = 'no encryption/integrity' FAIL_DEPRECATED_MAC = 'deprecated MAC' FAIL_1024BIT_MODULUS = 'using small 1024-bit modulus' FAIL_UNPROVEN = 'using unproven algorithm' WARN_CURVES_WEAK = 'using weak elliptic curves' WARN_RNDSIG_KEY = 'using weak random number generator could reveal the key' 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' WARN_TAG_SIZE_96 = 'using small 96-bit tag size' WARN_EXPERIMENTAL = 'using experimental algorithm' WARN_OBSOLETE = 'using obsolete algorithm' ALGORITHMS = { # Format: 'algorithm_name': [['version_first_appeared_in'], [reason_for_failure1, reason_for_failure2, ...], [warning1, warning2, ...]] 'kex': { 'diffie-hellman-group1-sha1': [['2.3.0,d0.28,l10.2', '6.6', '6.9'], [FAIL_1024BIT_MODULUS, FAIL_OPENSSH67_UNSAFE, FAIL_OPENSSH70_LOGJAM], [WARN_HASH_WEAK]], 'gss-group1-sha1-toWM5Slw5Ew8Mqkay+al2g==': [[], [FAIL_1024BIT_MODULUS, FAIL_OPENSSH67_UNSAFE, FAIL_OPENSSH70_LOGJAM], [WARN_HASH_WEAK]], 'gss-gex-sha1-toWM5Slw5Ew8Mqkay+al2g==': [[], [], [WARN_HASH_WEAK]], 'gss-gex-sha1-': [[], [], [WARN_HASH_WEAK]], 'gss-group1-sha1-': [[], [FAIL_1024BIT_MODULUS], [WARN_HASH_WEAK]], 'gss-group14-sha1-': [[], [], [WARN_HASH_WEAK]], 'gss-group14-sha1-toWM5Slw5Ew8Mqkay+al2g==': [[], [], [WARN_HASH_WEAK]], 'gss-group14-sha256-toWM5Slw5Ew8Mqkay+al2g==': [[]], 'gss-group15-sha512-toWM5Slw5Ew8Mqkay+al2g==': [[]], 'diffie-hellman-group1-sha256': [[], [FAIL_1024BIT_MODULUS]], 'diffie-hellman-group14-sha1': [['3.9,d0.53,l10.6.0'], [], [WARN_HASH_WEAK]], 'diffie-hellman-group14-sha256': [['7.3,d2016.73']], 'diffie-hellman-group14-sha256@ssh.com': [[]], 'diffie-hellman-group15-sha256': [[]], 'diffie-hellman-group15-sha256@ssh.com': [[]], 'diffie-hellman-group15-sha384@ssh.com': [[]], 'diffie-hellman-group15-sha512': [[]], 'diffie-hellman-group16-sha256': [[]], 'diffie-hellman-group16-sha384@ssh.com': [[]], 'diffie-hellman-group16-sha512': [['7.3,d2016.73']], 'diffie-hellman-group16-sha512@ssh.com': [[]], 'diffie-hellman-group17-sha512': [[]], 'diffie-hellman-group18-sha512': [['7.3']], 'diffie-hellman-group18-sha512@ssh.com': [[]], 'diffie-hellman-group-exchange-sha1': [['2.3.0', '6.6', None], [FAIL_OPENSSH67_UNSAFE], [WARN_HASH_WEAK]], 'diffie-hellman-group-exchange-sha256': [['4.4']], 'diffie-hellman-group-exchange-sha256@ssh.com': [[]], 'diffie-hellman-group-exchange-sha512@ssh.com': [[]], 'ecdh-sha2-curve25519': [[], []], 'ecdh-sha2-nistb233': [[], [WARN_CURVES_WEAK]], 'ecdh-sha2-nistb409': [[], [WARN_CURVES_WEAK]], 'ecdh-sha2-nistk163': [[], [WARN_CURVES_WEAK]], 'ecdh-sha2-nistk233': [[], [WARN_CURVES_WEAK]], 'ecdh-sha2-nistk283': [[], [WARN_CURVES_WEAK]], 'ecdh-sha2-nistk409': [[], [WARN_CURVES_WEAK]], 'ecdh-sha2-nistp192': [[], [WARN_CURVES_WEAK]], 'ecdh-sha2-nistp224': [[], [WARN_CURVES_WEAK]], '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]], 'ecdh-sha2-nistt571': [[], [WARN_CURVES_WEAK]], 'ecdh-sha2-1.3.132.0.10': [[]], # ECDH over secp256k1 (i.e.: the Bitcoin curve) 'curve25519-sha256@libssh.org': [['6.5,d2013.62,l10.6.0']], 'curve25519-sha256': [['7.4,d2018.76']], 'curve448-sha512': [[]], 'kexguess2@matt.ucc.asn.au': [['d2013.57']], 'rsa1024-sha1': [[], [FAIL_1024BIT_MODULUS], [WARN_HASH_WEAK]], 'rsa2048-sha256': [[]], 'sntrup4591761x25519-sha512@tinyssh.org': [['8.0'], [], [WARN_EXPERIMENTAL]], 'ext-info-c': [[]], # Extension negotiation (RFC 8308) 'ext-info-s': [[]], # Extension negotiation (RFC 8308) }, 'key': { 'ssh-rsa1': [[], [FAIL_WEAK_ALGORITHM]], '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'], [WARN_HASH_WEAK]], 'ssh-dss': [['2.1.0,d0.28,l10.2', '6.9'], [FAIL_1024BIT_MODULUS, FAIL_OPENSSH70_WEAK], [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]], 'ecdsa-sha2-1.3.132.0.10': [[], [], [WARN_RNDSIG_KEY]], # ECDSA over secp256k1 (i.e.: the Bitcoin curve) 'x509v3-sign-dss': [[], [FAIL_1024BIT_MODULUS, FAIL_OPENSSH70_WEAK], [WARN_RNDSIG_KEY]], 'x509v3-sign-rsa': [[], [], [WARN_HASH_WEAK]], 'x509v3-sign-rsa-sha256@ssh.com': [[]], 'x509v3-ssh-dss': [[], [FAIL_1024BIT_MODULUS, FAIL_OPENSSH70_WEAK], [WARN_RNDSIG_KEY]], 'x509v3-ssh-rsa': [[], [], [WARN_HASH_WEAK]], 'ssh-rsa-cert-v00@openssh.com': [['5.4', '6.9'], [FAIL_OPENSSH70_LEGACY], []], 'ssh-dss-cert-v00@openssh.com': [['5.4', '6.9'], [FAIL_1024BIT_MODULUS, FAIL_OPENSSH70_LEGACY], [WARN_RNDSIG_KEY]], 'ssh-rsa-cert-v01@openssh.com': [['5.6']], 'ssh-dss-cert-v01@openssh.com': [['5.6', '6.9'], [FAIL_1024BIT_MODULUS, FAIL_OPENSSH70_WEAK], [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]], 'rsa-sha2-256-cert-v01@openssh.com': [['7.8']], 'rsa-sha2-512-cert-v01@openssh.com': [['7.8']], 'ssh-rsa-sha256@ssh.com': [[]], 'ssh-dss-sha256@ssh.com': [[], [FAIL_1024BIT_MODULUS]], 'sk-ecdsa-sha2-nistp256-cert-v01@openssh.com': [['8.2'], [WARN_CURVES_WEAK], [WARN_RNDSIG_KEY]], 'sk-ecdsa-sha2-nistp256@openssh.com': [['8.2'], [WARN_CURVES_WEAK], [WARN_RNDSIG_KEY]], 'sk-ssh-ed25519-cert-v01@openssh.com': [['8.2']], 'sk-ssh-ed25519@openssh.com': [['8.2']], }, 'enc': { 'none': [['1.2.2,d2013.56,l10.2'], [FAIL_PLAINTEXT]], 'des': [[], [FAIL_WEAK_CIPHER], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]], 'des-cbc': [[], [FAIL_WEAK_CIPHER], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]], 'des-cbc-ssh1': [[], [FAIL_WEAK_CIPHER], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]], '3des': [[], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH74_UNSAFE, WARN_CIPHER_WEAK, WARN_CIPHER_MODE, WARN_BLOCK_SIZE]], '3des-cbc': [['1.2.2,d0.28,l10.2', '6.6', None], [FAIL_OPENSSH67_UNSAFE], [WARN_OPENSSH74_UNSAFE, WARN_CIPHER_WEAK, WARN_CIPHER_MODE, WARN_BLOCK_SIZE]], '3des-ctr': [['d0.52'], [FAIL_WEAK_CIPHER]], 'blowfish': [[], [FAIL_WEAK_ALGORITHM], [WARN_BLOCK_SIZE]], '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]], 'blowfish-ctr': [[], [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]], 'twofish192-cbc': [[], [], [WARN_CIPHER_MODE]], 'twofish256-cbc': [['d0.47', 'd2014.66'], [FAIL_DBEAR67_DISABLED], [WARN_CIPHER_MODE]], 'twofish-ctr': [[]], 'twofish128-ctr': [['d2015.68']], 'twofish192-ctr': [[]], 'twofish256-ctr': [['d2015.68']], 'serpent128-cbc': [[], [FAIL_DEPRECATED_CIPHER], [WARN_CIPHER_MODE]], 'serpent192-cbc': [[], [FAIL_DEPRECATED_CIPHER], [WARN_CIPHER_MODE]], 'serpent256-cbc': [[], [FAIL_DEPRECATED_CIPHER], [WARN_CIPHER_MODE]], 'serpent128-ctr': [[], [FAIL_DEPRECATED_CIPHER]], 'serpent192-ctr': [[], [FAIL_DEPRECATED_CIPHER]], 'serpent256-ctr': [[], [FAIL_DEPRECATED_CIPHER]], 'idea-cbc': [[], [FAIL_DEPRECATED_CIPHER], [WARN_CIPHER_MODE]], 'idea-ctr': [[], [FAIL_DEPRECATED_CIPHER]], 'cast128-ctr': [[], [FAIL_DEPRECATED_CIPHER]], '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': [[]], 'aes256-gcm': [[]], 'AEAD_AES_128_GCM': [[]], 'AEAD_AES_256_GCM': [[]], 'aes128-gcm@openssh.com': [['6.2']], 'aes256-gcm@openssh.com': [['6.2']], 'chacha20-poly1305': [[], [], [], [INFO_OPENSSH69_CHACHA]], 'chacha20-poly1305@openssh.com': [['6.5'], [], [], [INFO_OPENSSH69_CHACHA]], 'camellia128-cbc': [[], [], [WARN_CIPHER_MODE]], 'camellia128-ctr': [[]], 'camellia192-cbc': [[], [], [WARN_CIPHER_MODE]], 'camellia192-ctr': [[]], 'camellia256-cbc': [[], [], [WARN_CIPHER_MODE]], 'camellia256-ctr': [[]], 'crypticore128@ssh.com': [[], [FAIL_UNPROVEN]], 'seed-cbc@ssh.com': [[], [], [WARN_OBSOLETE, WARN_CIPHER_MODE]], }, '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-sha2-56': [[], [], [WARN_TAG_SIZE, WARN_ENCRYPT_AND_MAC]], 'hmac-sha2-224': [[], [], [WARN_TAG_SIZE, WARN_ENCRYPT_AND_MAC]], '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-sha2-384': [[], [], [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-sha3-224': [[], [], [WARN_ENCRYPT_AND_MAC]], 'hmac-sha3-256': [[], [], [WARN_ENCRYPT_AND_MAC]], 'hmac-sha3-384': [[], [], [WARN_ENCRYPT_AND_MAC]], 'hmac-sha3-512': [[], [], [WARN_ENCRYPT_AND_MAC]], 'hmac-sha256': [[], [], [WARN_ENCRYPT_AND_MAC]], 'hmac-sha256-96@ssh.com': [[], [], [WARN_ENCRYPT_AND_MAC, WARN_TAG_SIZE]], 'hmac-sha256@ssh.com': [[], [], [WARN_ENCRYPT_AND_MAC]], 'hmac-sha512': [[], [], [WARN_ENCRYPT_AND_MAC]], 'hmac-sha512@ssh.com': [[], [], [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-ripemd': [[], [FAIL_DEPRECATED_MAC], [WARN_OPENSSH72_LEGACY, WARN_ENCRYPT_AND_MAC]], '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-sha2-256-96-etm@openssh.com': [[], [], [WARN_TAG_SIZE_96]], # Despite the @openssh.com tag, it doesn't appear that this was ever shipped with OpenSSH; it is only implemented in AsyncSSH (?). 'hmac-sha2-512-96-etm@openssh.com': [[], [], [WARN_TAG_SIZE_96]], # Despite the @openssh.com tag, it doesn't appear that this was ever shipped with OpenSSH; it is only implemented in AsyncSSH (?). '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-32@openssh.com': [[], [], [WARN_ENCRYPT_AND_MAC, WARN_TAG_SIZE]], # Despite having the @openssh.com suffix, this may never have shipped with OpenSSH (!). 'umac-64-etm@openssh.com': [['6.2'], [], [WARN_TAG_SIZE]], 'umac-96@openssh.com': [[], [], [WARN_ENCRYPT_AND_MAC]], # Despite having the @openssh.com suffix, this may never have shipped with OpenSSH (!). 'umac-128-etm@openssh.com': [['6.2']], 'aes128-gcm': [[]], 'aes256-gcm': [[]], 'chacha20-poly1305@openssh.com': [[]], # Despite the @openssh.com tag, this was never shipped as a MAC in OpenSSH (only as a cipher); it is only implemented as a MAC in Syncplify. 'crypticore-mac@ssh.com': [[], [FAIL_UNPROVEN]], } } # type: Dict[str, Dict[str, List[List[Optional[str]]]]] class KexParty: def __init__(self, enc: List[str], mac: List[str], compression: List[str], languages: List[str]) -> None: self.__enc = enc self.__mac = mac self.__compression = compression self.__languages = languages @property def encryption(self) -> List[str]: return self.__enc @property def mac(self) -> List[str]: return self.__mac @property def compression(self) -> List[str]: return self.__compression @property def languages(self) -> List[str]: return self.__languages class Kex: def __init__(self, cookie: bytes, kex_algs: List[str], key_algs: List[str], cli: 'SSH2.KexParty', srv: 'SSH2.KexParty', follows: bool, unused: int = 0) -> None: 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 self.__rsa_key_sizes = {} # type: Dict[str, Tuple[int, int]] self.__dh_modulus_sizes = {} # type: Dict[str, Tuple[int, int]] self.__host_keys = {} # type: Dict[str, bytes] @property def cookie(self) -> bytes: return self.__cookie @property def kex_algorithms(self) -> List[str]: return self.__kex_algs @property def key_algorithms(self) -> List[str]: return self.__key_algs # client_to_server @property def client(self) -> 'SSH2.KexParty': return self.__client # server_to_client @property def server(self) -> 'SSH2.KexParty': return self.__server @property def follows(self) -> bool: return self.__follows @property def unused(self) -> int: return self.__unused def set_rsa_key_size(self, rsa_type: str, hostkey_size: int, ca_size: int = -1) -> None: self.__rsa_key_sizes[rsa_type] = (hostkey_size, ca_size) def rsa_key_sizes(self) -> Dict[str, Tuple[int, int]]: return self.__rsa_key_sizes def set_dh_modulus_size(self, gex_alg: str, modulus_size: int) -> None: self.__dh_modulus_sizes[gex_alg] = (modulus_size, -1) def dh_modulus_sizes(self) -> Dict[str, Tuple[int, int]]: return self.__dh_modulus_sizes def set_host_key(self, key_type: str, hostkey: bytes) -> None: self.__host_keys[key_type] = hostkey def host_keys(self) -> Dict[str, bytes]: return self.__host_keys def write(self, wbuf: 'WriteBuf') -> None: 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) -> bytes: wbuf = WriteBuf() self.write(wbuf) return wbuf.write_flush() @classmethod def parse(cls, payload: bytes) -> 'SSH2.Kex': 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 # Obtains host keys, checks their size, and derives their fingerprints. 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'] # Dict holding the host key types we should extract & parse. 'cert' is True to denote that a host key type handles certificates (thus requires additional parsing). 'variable_key_len' is True for host key types that can have variable sizes (True only for RSA types, as the rest are of fixed-size). After the host key type is fully parsed, the key 'parsed' is added with a value of True. HOST_KEY_TYPES = { 'ssh-rsa': {'cert': False, 'variable_key_len': True}, 'rsa-sha2-256': {'cert': False, 'variable_key_len': True}, 'rsa-sha2-512': {'cert': False, 'variable_key_len': True}, '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}, } @staticmethod def run(s: 'SSH.Socket', server_kex: 'SSH2.Kex') -> None: KEX_TO_DHGROUP = { 'diffie-hellman-group1-sha1': KexGroup1, 'diffie-hellman-group14-sha1': KexGroup14_SHA1, 'diffie-hellman-group14-sha256': KexGroup14_SHA256, 'curve25519-sha256': KexCurve25519_SHA256, 'curve25519-sha256@libssh.org': KexCurve25519_SHA256, 'diffie-hellman-group16-sha512': KexGroup16_SHA512, 'diffie-hellman-group18-sha512': KexGroup18_SHA512, 'diffie-hellman-group-exchange-sha1': KexGroupExchange_SHA1, 'diffie-hellman-group-exchange-sha256': KexGroupExchange_SHA256, 'ecdh-sha2-nistp256': KexNISTP256, 'ecdh-sha2-nistp384': KexNISTP384, 'ecdh-sha2-nistp521': KexNISTP521, # 'kexguess2@matt.ucc.asn.au': ??? } # Pick the first kex algorithm that the server supports, which we # happen to support as well. kex_str = None kex_group = None for server_kex_alg in server_kex.kex_algorithms: if server_kex_alg in KEX_TO_DHGROUP: kex_str = server_kex_alg kex_group = KEX_TO_DHGROUP[kex_str]() break if kex_str is not None and kex_group is not None: SSH2.HostKeyTest.perform_test(s, server_kex, kex_str, kex_group, SSH2.HostKeyTest.HOST_KEY_TYPES) @staticmethod def perform_test(s: 'SSH.Socket', server_kex: 'SSH2.Kex', kex_str: str, kex_group: 'KexDH', host_key_types: Dict[str, Dict[str, bool]]) -> None: hostkey_modulus_size = 0 ca_modulus_size = 0 # For each host key type... for host_key_type in host_key_types: # Skip those already handled (i.e.: those in the RSA family, as testing one tests them all). if 'parsed' in host_key_types[host_key_type] and host_key_types[host_key_type]['parsed']: continue # If this host key type is supported by the server, we test it. if host_key_type in server_kex.key_algorithms: cert = host_key_types[host_key_type]['cert'] variable_key_len = host_key_types[host_key_type]['variable_key_len'] # If the connection is closed, re-open it and get the kex again. if not s.is_connected(): s.connect() unused = None # pylint: disable=unused-variable unused2 = None # pylint: disable=unused-variable unused, unused2, err = s.get_banner() if err is not None: s.close() return # Parse the server's initial KEX. packet_type = 0 # pylint: disable=unused-variable packet_type, payload = s.read_packet() SSH2.Kex.parse(payload) # Send the server our KEXINIT message, using only our # selected kex and host key type. Send the server's own # list of ciphers and MACs back to it (this doesn't # matter, really). client_kex = SSH2.Kex(os.urandom(16), [kex_str], [host_key_type], server_kex.client, server_kex.server, False, 0) s.write_byte(SSH.Protocol.MSG_KEXINIT) client_kex.write(s) s.send_packet() # Do the initial DH exchange. The server responds back # with the host key and its length. Bingo. We also get back the host key fingerprint. kex_group.send_init(s) host_key = kex_group.recv_reply(s, variable_key_len) if host_key is not None: server_kex.set_host_key(host_key_type, host_key) hostkey_modulus_size = kex_group.get_hostkey_size() ca_modulus_size = kex_group.get_ca_size() # Close the socket, as the connection has # been put in a state that later tests can't use. s.close() # If the host key modulus or CA modulus was successfully parsed, check to see that its a safe size. if hostkey_modulus_size > 0 or ca_modulus_size > 0: # Set the hostkey size for all RSA key types since 'ssh-rsa', # 'rsa-sha2-256', etc. are all using the same host key. # Note, however, that this may change in the future. if cert is False and host_key_type in SSH2.HostKeyTest.RSA_FAMILY: for rsa_type in SSH2.HostKeyTest.RSA_FAMILY: server_kex.set_rsa_key_size(rsa_type, hostkey_modulus_size) elif cert is True: server_kex.set_rsa_key_size(host_key_type, hostkey_modulus_size, ca_modulus_size) # Keys smaller than 2048 result in a failure. Update the database accordingly. if (cert is False) and (hostkey_modulus_size < 2048): 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)): # 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) alg_list.append(['using small %d-bit modulus' % min_modulus]) # If this host key type is in the RSA family, then mark them all as parsed (since results in one are valid for them all). if host_key_type in SSH2.HostKeyTest.RSA_FAMILY: for rsa_type in SSH2.HostKeyTest.RSA_FAMILY: host_key_types[rsa_type]['parsed'] = True else: host_key_types[host_key_type]['parsed'] = True # Performs DH group exchanges to find what moduli are supported, and checks # their size. class GEXTest: # Creates a new connection to the server. Returns True on success, or False. @staticmethod def reconnect(s: 'SSH.Socket', gex_alg: str) -> bool: if s.is_connected(): return True s.connect() unused = None # pylint: disable=unused-variable unused2 = None # pylint: disable=unused-variable unused, unused2, err = s.get_banner() if err is not None: s.close() return False # Parse the server's initial KEX. packet_type = 0 # pylint: disable=unused-variable packet_type, payload = s.read_packet(2) kex = SSH2.Kex.parse(payload) # Send our KEX using the specified group-exchange and most of the # server's own values. client_kex = SSH2.Kex(os.urandom(16), [gex_alg], kex.key_algorithms, kex.client, kex.server, False, 0) s.write_byte(SSH.Protocol.MSG_KEXINIT) client_kex.write(s) s.send_packet() return True # Runs the DH moduli test against the specified target. @staticmethod def run(s: 'SSH.Socket', kex: 'SSH2.Kex') -> None: GEX_ALGS = { 'diffie-hellman-group-exchange-sha1': KexGroupExchange_SHA1, 'diffie-hellman-group-exchange-sha256': KexGroupExchange_SHA256, } # The previous RSA tests put the server in a state we can't # test. So we need a new connection to start with a clean # slate. if s.is_connected(): s.close() # Check if the server supports any of the group-exchange # algorithms. If so, test each one. for gex_alg in GEX_ALGS: if gex_alg in kex.kex_algorithms: if SSH2.GEXTest.reconnect(s, gex_alg) is False: break kex_group = GEX_ALGS[gex_alg]() smallest_modulus = -1 # First try a range of weak sizes. try: kex_group.send_init_gex(s, 512, 1024, 1536) kex_group.recv_reply(s, False) # Its been observed that servers will return a group # larger than the requested max. So just because we # got here, doesn't mean the server is vulnerable... smallest_modulus = kex_group.get_dh_modulus_size() except Exception: pass finally: s.close() # Try an array of specific modulus sizes... one at a time. reconnect_failed = False for bits in [512, 768, 1024, 1536, 2048, 3072, 4096]: # If we found one modulus size already, but we're about # to test a larger one, don't bother. if bits >= smallest_modulus > 0: break if SSH2.GEXTest.reconnect(s, gex_alg) is False: reconnect_failed = True break try: 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: # import traceback # print(traceback.format_exc()) pass finally: # The server is in a state that is not re-testable, # so there's nothing else to do with this open # connection. s.close() if smallest_modulus > 0: kex.set_dh_modulus_size(gex_alg, smallest_modulus) # We flag moduli smaller than 2048 as a failure. if smallest_modulus < 2048: text = 'using small %d-bit modulus' % smallest_modulus lst = SSH2.KexDB.ALGORITHMS['kex'][gex_alg] # For 'diffie-hellman-group-exchange-sha256', add # a failure reason. if len(lst) == 1: lst.append([text]) # For 'diffie-hellman-group-exchange-sha1', delete # the existing failure reason (which is vague), and # insert our own. else: del lst[1] lst.insert(1, [text]) if reconnect_failed: break class SSH1: class CRC32: def __init__(self) -> None: self._table = [0] * 256 for i in range(256): crc = 0 n = i for _ in range(8): x = (crc ^ n) & 1 crc = (crc >> 1) ^ (x * 0xedb88320) n = n >> 1 self._table[i] = crc def calc(self, v: bytes) -> int: crc, length = 0, len(v) for i in range(length): n = ord(v[i:i + 1]) n = n ^ (crc & 0xff) crc = (crc >> 8) ^ self._table[n] return crc _crc32 = None # type: Optional[SSH1.CRC32] CIPHERS = ['none', 'idea', 'des', '3des', 'tss', 'rc4', 'blowfish'] AUTHS = ['none', 'rhosts', 'rsa', 'password', 'rhosts_rsa', 'tis', 'kerberos'] @classmethod def crc32(cls, v: bytes) -> int: if cls._crc32 is None: cls._crc32 = cls.CRC32() return cls._crc32.calc(v) 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' 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]], } } # type: Dict[str, Dict[str, List[List[Optional[str]]]]] class PublicKeyMessage: def __init__(self, cookie: bytes, skey: Tuple[int, int, int], hkey: Tuple[int, int, int], pflags: int, cmask: int, amask: int) -> None: if len(skey) != 3: raise ValueError('invalid server key pair: {}'.format(skey)) if len(hkey) != 3: raise ValueError('invalid host key pair: {}'.format(hkey)) 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) -> bytes: return self.__cookie @property def server_key_bits(self) -> int: return self.__server_key[0] @property def server_key_public_exponent(self) -> int: return self.__server_key[1] @property def server_key_public_modulus(self) -> int: return self.__server_key[2] @property def host_key_bits(self) -> int: return self.__host_key[0] @property def host_key_public_exponent(self) -> int: return self.__host_key[1] @property def host_key_public_modulus(self) -> int: return self.__host_key[2] @property def host_key_fingerprint_data(self) -> bytes: # 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 @property def protocol_flags(self) -> int: return self.__protocol_flags @property def supported_ciphers_mask(self) -> int: return self.__supported_ciphers_mask @property def supported_ciphers(self) -> List[str]: ciphers = [] for i in range(len(SSH1.CIPHERS)): if self.__supported_ciphers_mask & (1 << i) != 0: ciphers.append(utils.to_text(SSH1.CIPHERS[i])) return ciphers @property def supported_authentications_mask(self) -> int: return self.__supported_authentications_mask @property def supported_authentications(self) -> List[str]: auths = [] for i in range(1, len(SSH1.AUTHS)): if self.__supported_authentications_mask & (1 << i) != 0: auths.append(utils.to_text(SSH1.AUTHS[i])) return auths def write(self, wbuf: 'WriteBuf') -> None: 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) -> bytes: wbuf = WriteBuf() self.write(wbuf) return wbuf.write_flush() @classmethod def parse(cls, payload: bytes) -> 'SSH1.PublicKeyMessage': 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: def __init__(self, data: Optional[bytes] = None) -> None: super(ReadBuf, self).__init__() self._buf = io.BytesIO(data) if data is not None else io.BytesIO() self._len = len(data) if data is not None else 0 @property def unread_len(self) -> int: return self._len - self._buf.tell() def read(self, size: int) -> bytes: return self._buf.read(size) def read_byte(self) -> int: v = struct.unpack('B', self.read(1))[0] # type: int return v def read_bool(self) -> bool: return self.read_byte() != 0 def read_int(self) -> int: v = struct.unpack('>I', self.read(4))[0] # type: int return v def read_list(self) -> List[str]: list_size = self.read_int() return self.read(list_size).decode('utf-8', 'replace').split(',') def read_string(self) -> bytes: n = self.read_int() return self.read(n) @classmethod def _parse_mpint(cls, v: bytes, pad: bytes, f: str) -> int: r = 0 if len(v) % 4 != 0: v = pad * (4 - (len(v) % 4)) + v for i in range(0, len(v), 4): r = (r << 32) | struct.unpack(f, v[i:i + 4])[0] return r def read_mpint1(self) -> int: # 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) -> int: # NOTE: Section 5 @ https://www.ietf.org/rfc/rfc4251.txt v = self.read_string() if len(v) == 0: return 0 pad, f = (b'\xff', '>i') if ord(v[0:1]) & 0x80 != 0 else (b'\x00', '>I') return self._parse_mpint(v, pad, f) def read_line(self) -> str: return self._buf.readline().rstrip().decode('utf-8', 'replace') def reset(self) -> None: self._buf = io.BytesIO() self._len = 0 class WriteBuf: def __init__(self, data: Optional[bytes] = None) -> None: super(WriteBuf, self).__init__() self._wbuf = io.BytesIO(data) if data is not None else io.BytesIO() def write(self, data: bytes) -> 'WriteBuf': self._wbuf.write(data) return self def write_byte(self, v: int) -> 'WriteBuf': return self.write(struct.pack('B', v)) def write_bool(self, v: bool) -> 'WriteBuf': return self.write_byte(1 if v else 0) def write_int(self, v: int) -> 'WriteBuf': return self.write(struct.pack('>I', v)) def write_string(self, v: Union[bytes, str]) -> 'WriteBuf': 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: List[str]) -> 'WriteBuf': return self.write_string(u','.join(v)) @classmethod def _bitlength(cls, n: int) -> int: try: return n.bit_length() except AttributeError: return len(bin(n)) - (2 if n > 0 else 3) @classmethod def _create_mpint(cls, n: int, signed: bool = True, bits: Optional[int] = None) -> bytes: if bits is None: bits = cls._bitlength(n) length = bits // 8 + (1 if n != 0 else 0) ql = (length + 7) // 8 fmt, v2 = '>{}Q'.format(ql), [0] * 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: int) -> 'WriteBuf': # 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: int) -> 'WriteBuf': # 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: Union[bytes, str]) -> 'WriteBuf': if not isinstance(v, bytes): v = bytes(bytearray(v, 'utf-8')) v += b'\r\n' return self.write(v) def write_flush(self) -> bytes: payload = self._wbuf.getvalue() self._wbuf.truncate(0) self._wbuf.seek(0) return payload def reset(self) -> None: self._wbuf = io.BytesIO() 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 MSG_KEXINIT = 20 MSG_NEWKEYS = 21 MSG_KEXDH_INIT = 30 MSG_KEXDH_REPLY = 31 MSG_KEXDH_GEX_REQUEST = 34 MSG_KEXDH_GEX_GROUP = 31 MSG_KEXDH_GEX_INIT = 32 MSG_KEXDH_GEX_REPLY = 33 class Product: # pylint: disable=too-few-public-methods OpenSSH = 'OpenSSH' DropbearSSH = 'Dropbear SSH' LibSSH = 'libssh' TinySSH = 'TinySSH' PuTTY = 'PuTTY' class Software: def __init__(self, vendor: Optional[str], product: str, version: str, patch: Optional[str], os_version: Optional[str]) -> None: self.__vendor = vendor self.__product = product self.__version = version self.__patch = patch self.__os = os_version @property def vendor(self) -> Optional[str]: return self.__vendor @property def product(self) -> str: return self.__product @property def version(self) -> str: return self.__version @property def patch(self) -> Optional[str]: return self.__patch @property def os(self) -> Optional[str]: return self.__os def compare_version(self, other: Union[None, 'SSH.Software', str]) -> int: # pylint: disable=too-many-branches if other is None: return 1 if isinstance(other, SSH.Software): other = '{}{}'.format(other.version, other.patch or '') else: other = str(other) mx = re.match(r'^([\d\.]+\d+)(.*)$', other) if mx is not None: oversion, opatch = mx.group(1), mx.group(2).strip() else: oversion, opatch = other, '' if self.version < oversion: return -1 elif self.version > oversion: return 1 spatch = self.patch or '' if self.product == SSH.Product.DropbearSSH: if not re.match(r'^test\d.*$', opatch): opatch = 'z{}'.format(opatch) if not re.match(r'^test\d.*$', spatch): spatch = 'z{}'.format(spatch) elif self.product == SSH.Product.OpenSSH: mx1 = re.match(r'^p\d(.*)', opatch) mx2 = re.match(r'^p\d(.*)', spatch) if not (bool(mx1) and bool(mx2)): if mx1 is not None: opatch = mx1.group(1) if mx2 is not None: spatch = mx2.group(1) if spatch < opatch: return -1 elif spatch > opatch: return 1 return 0 def between_versions(self, vfrom: str, vtill: str) -> bool: if bool(vfrom) and self.compare_version(vfrom) < 0: return False if bool(vtill) and self.compare_version(vtill) > 0: return False return True def display(self, full: bool = True) -> str: r = '{} '.format(self.vendor) if bool(self.vendor) else '' r += self.product if bool(self.version): r += ' {}'.format(self.version) if full: patch = self.patch or '' if self.product == SSH.Product.OpenSSH: mx = re.match(r'^(p\d)(.*)$', patch) if mx is not None: r += mx.group(1) patch = mx.group(2).strip() if bool(patch): r += ' ({})'.format(patch) if bool(self.os): r += ' running on {}'.format(self.os) return r def __str__(self) -> str: return self.display() def __repr__(self) -> str: r = 'vendor={}, '.format(self.vendor) if bool(self.vendor) else '' r += 'product={}'.format(self.product) if bool(self.version): r += ', version={}'.format(self.version) if bool(self.patch): r += ', patch={}'.format(self.patch) if bool(self.os): r += ', os={}'.format(self.os) return '<{}({})>'.format(self.__class__.__name__, r) @staticmethod def _fix_patch(patch: str) -> Optional[str]: return re.sub(r'^[-_\.]+', '', patch) or None @staticmethod def _fix_date(d: Optional[str]) -> Optional[str]: if d is not None and len(d) == 8: return '{}-{}-{}'.format(d[:4], d[4:6], d[6:8]) else: return None @classmethod def _extract_os_version(cls, c: Optional[str]) -> Optional[str]: if c is None: return None mx = re.match(r'^NetBSD(?:_Secure_Shell)?(?:[\s-]+(\d{8})(.*))?$', c) if mx is not None: d = cls._fix_date(mx.group(1)) return 'NetBSD' if d is None else 'NetBSD ({})'.format(d) mx = re.match(r'^FreeBSD(?:\slocalisations)?[\s-]+(\d{8})(.*)$', c) if not bool(mx): mx = re.match(r'^[^@]+@FreeBSD\.org[\s-]+(\d{8})(.*)$', c) if mx is not None: d = cls._fix_date(mx.group(1)) return 'FreeBSD' if d is None else 'FreeBSD ({})'.format(d) w = ['RemotelyAnywhere', 'DesktopAuthority', 'RemoteSupportManager'] for win_soft in w: mx = re.match(r'^in ' + win_soft + r' ([\d\.]+\d)$', c) if mx is not None: ver = mx.group(1) return 'Microsoft Windows ({} {})'.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: 'SSH.Banner') -> Optional['SSH.Software']: # pylint: disable=too-many-return-statements software = str(banner.software) mx = re.match(r'^dropbear_([\d\.]+\d+)(.*)', software) v = None # type: Optional[str] if mx is not None: 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 is not None: patch = cls._fix_patch(mx.group(2)) v, p = 'OpenBSD', SSH.Product.OpenSSH v = None 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 is not None: patch = cls._fix_patch(mx.group(2)) v, p = None, SSH.Product.LibSSH 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 is not None: patch = cls._fix_patch(mx.group(2)) v, p = None, SSH.Product.LibSSH 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 is not None: 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 is not None: 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 is not None: v, p = 'Cisco', 'IOS/PIX sshd' return cls(v, p, mx.group(1), None, None) mx = re.match(r'^tinyssh_(.*)', software) if mx is not None: return cls(None, SSH.Product.TinySSH, mx.group(1), None, None) mx = re.match(r'^PuTTY_Release_(.*)', software) if mx: return cls(None, SSH.Product.PuTTY, mx.group(1), None, None) return None 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)) def __init__(self, protocol: Tuple[int, int], software: Optional[str], comments: Optional[str], valid_ascii: bool) -> None: self.__protocol = protocol self.__software = software self.__comments = comments self.__valid_ascii = valid_ascii @property def protocol(self) -> Tuple[int, int]: return self.__protocol @property def software(self) -> Optional[str]: return self.__software @property def comments(self) -> Optional[str]: return self.__comments @property def valid_ascii(self) -> bool: return self.__valid_ascii def __str__(self) -> str: r = 'SSH-{}.{}'.format(self.protocol[0], self.protocol[1]) if self.software is not None: r += '-{}'.format(self.software) if bool(self.comments): r += ' {}'.format(self.comments) return r def __repr__(self) -> str: p = '{}.{}'.format(self.protocol[0], self.protocol[1]) r = 'protocol={}'.format(p) if self.software is not None: r += ', software={}'.format(self.software) if bool(self.comments): r += ', comments={}'.format(self.comments) return '<{}({})>'.format(self.__class__.__name__, r) @classmethod def parse(cls, banner: str) -> Optional['SSH.Banner']: valid_ascii = utils.is_print_ascii(banner) ascii_banner = utils.to_print_ascii(banner) mx = cls.RX_BANNER.match(ascii_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(r'\s+', ' ', comments) return cls(protocol, software, comments, valid_ascii) class Fingerprint: def __init__(self, fpd: bytes) -> None: self.__fpd = fpd @property def md5(self) -> str: h = hashlib.md5(self.__fpd).hexdigest() r = u':'.join(h[i:i + 2] for i in range(0, len(h), 2)) return u'MD5:{}'.format(r) @property def sha256(self) -> str: h = base64.b64encode(hashlib.sha256(self.__fpd).digest()) r = h.decode('ascii').rstrip('=') return u'SHA256:{}'.format(r) class Algorithm: class Timeframe: def __init__(self) -> None: self.__storage = {} # type: Dict[str, List[Optional[str]]] def __contains__(self, product: str) -> bool: return product in self.__storage def __getitem__(self, product): # type: (str) -> Sequence[Optional[str]] return tuple(self.__storage.get(product, [None] * 4)) def __str__(self) -> str: return self.__storage.__str__() def __repr__(self) -> str: return self.__str__() def get_from(self, product: str, for_server: bool = True) -> Optional[str]: return self[product][0 if bool(for_server) else 2] def get_till(self, product: str, for_server: bool = True) -> Optional[str]: return self[product][1 if bool(for_server) else 3] def _update(self, versions: Optional[str], pos: int) -> None: ssh_versions = {} # type: Dict[str, str] 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): continue ssh_versions[ssh_prod] = ssh_ver for ssh_product, ssh_version in ssh_versions.items(): if ssh_product not in self.__storage: self.__storage[ssh_product] = [None] * 4 prev = self[ssh_product][pos] if (prev is None or (prev < ssh_version and pos % 2 == 0) or (prev > ssh_version and pos % 2 == 1)): self.__storage[ssh_product][pos] = ssh_version def update(self, versions: List[Optional[str]], for_server: Optional[bool] = None) -> 'SSH.Algorithm.Timeframe': for_cli = for_server is None or for_server is False for_srv = for_server is None or for_server is True vlen = len(versions) for i in range(min(3, vlen)): if for_srv and i < 2: self._update(versions[i], i) if for_cli and (i % 2 == 0 or vlen == 2): self._update(versions[i], 3 - 0**i) return self @staticmethod def get_ssh_version(version_desc: str) -> Tuple[str, str, bool]: is_client = version_desc.endswith('C') if is_client: version_desc = version_desc[:-1] if version_desc.startswith('d'): return SSH.Product.DropbearSSH, version_desc[1:], is_client elif version_desc.startswith('l1'): return SSH.Product.LibSSH, version_desc[2:], is_client else: return SSH.Product.OpenSSH, version_desc, is_client @classmethod def get_since_text(cls, versions: List[Optional[str]]) -> Optional[str]: tv = [] if len(versions) == 0 or versions[0] is None: return None for v in versions[0].split(','): ssh_prod, ssh_ver, is_cli = cls.get_ssh_version(v) if not ssh_ver: continue if ssh_prod in [SSH.Product.LibSSH]: continue if is_cli: ssh_ver = '{} (client only)'.format(ssh_ver) tv.append('{} {}'.format(ssh_prod, ssh_ver)) if len(tv) == 0: return None return 'available since ' + ', '.join(tv).rstrip(', ') class Algorithms: def __init__(self, pkm: Optional[SSH1.PublicKeyMessage], kex: Optional[SSH2.Kex]) -> None: self.__ssh1kex = pkm self.__ssh2kex = kex @property def ssh1kex(self) -> Optional[SSH1.PublicKeyMessage]: return self.__ssh1kex @property def ssh2kex(self) -> Optional[SSH2.Kex]: return self.__ssh2kex @property def ssh1(self) -> Optional['SSH.Algorithms.Item']: if self.ssh1kex is None: return None item = SSH.Algorithms.Item(1, SSH1.KexDB.ALGORITHMS) item.add('key', [u'ssh-rsa1']) item.add('enc', self.ssh1kex.supported_ciphers) item.add('aut', self.ssh1kex.supported_authentications) return item @property def ssh2(self) -> Optional['SSH.Algorithms.Item']: if self.ssh2kex is None: return None item = SSH.Algorithms.Item(2, SSH2.KexDB.ALGORITHMS) item.add('kex', self.ssh2kex.kex_algorithms) item.add('key', self.ssh2kex.key_algorithms) item.add('enc', self.ssh2kex.server.encryption) item.add('mac', self.ssh2kex.server.mac) return item @property def values(self) -> Iterable['SSH.Algorithms.Item']: for item in [self.ssh1, self.ssh2]: if item is not None: yield item @property def maxlen(self) -> int: def _ml(items: Sequence[str]) -> int: return max(len(i) for i in items) maxlen = 0 if self.ssh1kex is not None: maxlen = max(_ml(self.ssh1kex.supported_ciphers), _ml(self.ssh1kex.supported_authentications), maxlen) if self.ssh2kex is not None: maxlen = max(_ml(self.ssh2kex.kex_algorithms), _ml(self.ssh2kex.key_algorithms), _ml(self.ssh2kex.server.encryption), _ml(self.ssh2kex.server.mac), maxlen) return maxlen def get_ssh_timeframe(self, for_server: Optional[bool] = None) -> 'SSH.Algorithm.Timeframe': timeframe = SSH.Algorithm.Timeframe() for alg_pair in self.values: alg_db = alg_pair.db for alg_type, alg_list in alg_pair.items(): for alg_name in alg_list: alg_name_native = utils.to_text(alg_name) alg_desc = alg_db[alg_type].get(alg_name_native) if alg_desc is None: continue versions = alg_desc[0] timeframe.update(versions, for_server) return timeframe def get_recommendations(self, software: Optional['SSH.Software'], for_server: bool = True) -> Tuple[Optional['SSH.Software'], Dict[int, Dict[str, Dict[str, Dict[str, int]]]]]: # pylint: disable=too-many-locals,too-many-statements vproducts = [SSH.Product.OpenSSH, SSH.Product.DropbearSSH, SSH.Product.LibSSH, SSH.Product.TinySSH] # Set to True if server is not one of vproducts, above. unknown_software = False if software is not None: if software.product not in vproducts: unknown_software = True # The code below is commented out because it would try to guess what the server is, # usually resulting in wild & incorrect recommendations. # if software is None: # ssh_timeframe = self.get_ssh_timeframe(for_server) # for product in vproducts: # if product not in ssh_timeframe: # continue # version = ssh_timeframe.get_from(product, for_server) # if version is not None: # software = SSH.Software(None, product, version, None, None) # break rec = {} # type: Dict[int, Dict[str, Dict[str, Dict[str, int]]]] if software is None: unknown_software = True for alg_pair in self.values: sshv, alg_db = alg_pair.sshv, alg_pair.db rec[sshv] = {} for alg_type, alg_list in alg_pair.items(): if alg_type == 'aut': continue rec[sshv][alg_type] = {'add': {}, 'del': {}, 'chg': {}} for n, alg_desc in alg_db[alg_type].items(): versions = alg_desc[0] empty_version = False if len(versions) == 0 or versions[0] is None: empty_version = True else: matches = False if unknown_software: matches = True for v in versions[0].split(','): ssh_prefix, ssh_version, is_cli = SSH.Algorithm.get_ssh_version(v) if not ssh_version: continue if (software is not None) and (ssh_prefix != software.product): continue if is_cli and for_server: continue if (software is not None) and (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: # Don't recommend certificate or token types; these will only appear in the server's list if they are fully configured & functional on the server. if faults > 0 or (alg_type == 'key' and (('-cert-' in n) or (n.startswith('sk-')))) or empty_version: continue rec[sshv][alg_type]['add'][n] = 0 else: if faults == 0: continue if n in ['diffie-hellman-group-exchange-sha256', 'rsa-sha2-256', 'rsa-sha2-512', 'ssh-rsa-cert-v01@openssh.com']: rec[sshv][alg_type]['chg'][n] = faults else: rec[sshv][alg_type]['del'][n] = faults # If we are working with unknown software, drop all add recommendations, because we don't know if they're valid. if unknown_software: rec[sshv][alg_type]['add'] = {} add_count = len(rec[sshv][alg_type]['add']) del_count = len(rec[sshv][alg_type]['del']) chg_count = len(rec[sshv][alg_type]['chg']) new_alg_count = len(alg_list) + add_count - del_count if new_alg_count < 1 and del_count > 0: mf = min(rec[sshv][alg_type]['del'].values()) new_del = {} for k, cf in rec[sshv][alg_type]['del'].items(): if cf != mf: new_del[k] = cf 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 chg_count == 0: del rec[sshv][alg_type]['chg'] if len(rec[sshv][alg_type]) == 0: del rec[sshv][alg_type] if len(rec[sshv]) == 0: del rec[sshv] return software, rec class Item: def __init__(self, sshv: int, db: Dict[str, Dict[str, List[List[Optional[str]]]]]) -> None: self.__sshv = sshv self.__db = db self.__storage = {} # type: Dict[str, List[str]] @property def sshv(self) -> int: return self.__sshv @property def db(self) -> Dict[str, Dict[str, List[List[Optional[str]]]]]: return self.__db def add(self, key: str, value: List[str]) -> None: self.__storage[key] = value def items(self) -> Iterable[Tuple[str, List[str]]]: return self.__storage.items() 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 # = 1. If it affects servers, but is a local issue only, # then affected = 1 + 4 = 5. # pylint: disable=bad-whitespace CVE = { 'Dropbear SSH': [ ['0.0', '2018.76', 1, 'CVE-2018-15599', 5.0, 'remote users may enumerate users on the system'], ['0.0', '2017.74', 5, 'CVE-2017-9079', 4.7, 'local users can read certain files as root'], ['0.0', '2017.74', 5, 'CVE-2017-9078', 9.3, 'local users may elevate privileges to root under certain conditions'], ['0.0', '2016.73', 5, 'CVE-2016-7409', 2.1, 'local users can read process memory under limited conditions'], ['0.0', '2016.73', 1, 'CVE-2016-7408', 6.5, 'remote users can execute arbitrary code'], ['0.0', '2016.73', 5, 'CVE-2016-7407', 10.0, 'local users can execute arbitrary code'], ['0.0', '2016.73', 1, 'CVE-2016-7406', 10.0, 'remote users can execute arbitrary code'], ['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 via a compressed packet (memory consumption)'], ['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 via large number of connections (slot exhaustion)'], ['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': [ ['0.6.4', '0.6.4', 1, 'CVE-2018-10933', 6.4, 'authentication bypass'], ['0.7.0', '0.7.5', 1, 'CVE-2018-10933', 6.4, 'authentication bypass'], ['0.8.0', '0.8.3', 1, 'CVE-2018-10933', 6.4, 'authentication bypass'], ['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)']], 'OpenSSH': [ ['7.2', '7.2p2', 1, 'CVE-2016-6515', 7.8, 'cause DoS via long password string (crypt CPU consumption)'], ['1.2.2', '7.2', 1, 'CVE-2016-3115', 5.5, 'bypass command restrictions via crafted X11 forwarding data'], ['5.4', '7.1', 1, 'CVE-2016-1907', 5.0, 'cause DoS via crafted network traffic (out of bounds read)'], ['5.4', '7.1p1', 2, 'CVE-2016-0778', 4.6, 'cause DoS via requesting many forwardings (heap based buffer overflow)'], ['5.0', '7.1p1', 2, 'CVE-2016-0777', 4.0, 'leak data via allowing transfer of entire buffer'], ['6.0', '7.2p2', 5, 'CVE-2015-8325', 7.2, 'privilege escalation via triggering crafted environment'], ['6.8', '6.9', 5, 'CVE-2015-6565', 7.2, 'cause DoS via writing to a device (terminal disruption)'], ['5.0', '6.9', 5, 'CVE-2015-6564', 6.9, 'privilege escalation via leveraging sshd uid'], ['5.0', '6.9', 5, 'CVE-2015-6563', 1.9, 'conduct impersonation attack'], ['6.9p1', '6.9p1', 1, 'CVE-2015-5600', 8.5, 'cause Dos or aid in conduct brute force attack (CPU consumption)'], ['6.0', '6.6', 1, 'CVE-2015-5352', 4.3, 'bypass access restrictions via a specific connection'], ['6.0', '6.6', 2, 'CVE-2014-2653', 5.8, 'bypass SSHFP DNS RR check via unacceptable host certificate'], ['5.0', '6.5', 1, 'CVE-2014-2532', 5.8, 'bypass environment restrictions via specific string before wildcard'], ['1.2', '6.4', 1, 'CVE-2014-1692', 7.5, 'cause DoS via triggering error condition (memory corruption)'], ['6.2', '6.3', 1, 'CVE-2013-4548', 6.0, 'bypass command restrictions via crafted packet data'], ['1.2', '5.6', 1, 'CVE-2012-0814', 3.5, 'leak data via debug messages'], ['1.2', '5.8', 1, 'CVE-2011-5000', 3.5, 'cause DoS via large value in certain length field (memory consumption)'], ['5.6', '5.7', 2, 'CVE-2011-0539', 5.0, 'leak data or conduct hash collision attack'], ['1.2', '6.1', 1, 'CVE-2010-5107', 5.0, 'cause DoS via large number of connections (slot exhaustion)'], ['1.2', '5.8', 1, 'CVE-2010-4755', 4.0, 'cause DoS via crafted glob expression (CPU and memory consumption)'], ['1.2', '5.6', 1, 'CVE-2010-4478', 7.5, 'bypass authentication check via crafted values'], ['4.3', '4.8', 1, 'CVE-2009-2904', 6.9, 'privilege escalation via hard links to setuid programs'], ['4.0', '5.1', 1, 'CVE-2008-5161', 2.6, 'recover plaintext data from ciphertext'], ['1.2', '4.6', 1, 'CVE-2008-4109', 5.0, 'cause DoS via multiple login attempts (slot exhaustion)'], ['1.2', '4.8', 1, 'CVE-2008-1657', 6.5, 'bypass command restrictions via modifying session file'], ['1.2.2', '4.9', 1, 'CVE-2008-1483', 6.9, 'hijack forwarded X11 connections'], ['4.0', '4.6', 1, 'CVE-2007-4752', 7.5, 'privilege escalation via causing an X client to be trusted'], ['4.3p2', '4.3p2', 1, 'CVE-2007-3102', 4.3, 'allow attacker to write random data to audit log'], ['1.2', '4.6', 1, 'CVE-2007-2243', 5.0, 'discover valid usernames through different responses'], ['4.4', '4.4', 1, 'CVE-2006-5794', 7.5, 'bypass authentication'], ['4.1', '4.1p1', 1, 'CVE-2006-5229', 2.6, 'discover valid usernames through different time delays'], ['1.2', '4.3p2', 1, 'CVE-2006-5052', 5.0, 'discover valid usernames through different responses'], ['1.2', '4.3p2', 1, 'CVE-2006-5051', 9.3, 'cause DoS or execute arbitrary code (double free)'], ['4.5', '4.5', 1, 'CVE-2006-4925', 5.0, 'cause DoS via invalid protocol sequence (crash)'], ['1.2', '4.3p2', 1, 'CVE-2006-4924', 7.8, 'cause DoS via crafted packet (CPU consumption)'], ['3.8.1p1', '3.8.1p1', 1, 'CVE-2006-0883', 5.0, 'cause DoS via connecting multiple times (client connection refusal)'], ['3.0', '4.2p1', 1, 'CVE-2006-0225', 4.6, 'execute arbitrary code'], ['2.1', '4.1p1', 1, 'CVE-2005-2798', 5.0, 'leak data about authentication credentials'], ['3.5', '3.5p1', 1, 'CVE-2004-2760', 6.8, 'leak data through different connection states'], ['2.3', '3.7.1p2', 1, 'CVE-2004-2069', 5.0, 'cause DoS via large number of connections (slot exhaustion)'], ['3.0', '3.4p1', 1, 'CVE-2004-0175', 4.3, 'leak data through directoy traversal'], ['1.2', '3.9p1', 1, 'CVE-2003-1562', 7.6, 'leak data about authentication credentials'], ['3.1p1', '3.7.1p1', 1, 'CVE-2003-0787', 7.5, 'privilege escalation via modifying stack'], ['3.1p1', '3.7.1p1', 1, 'CVE-2003-0786', 10.0, 'privilege escalation via bypassing authentication'], ['1.0', '3.7.1', 1, 'CVE-2003-0695', 7.5, 'cause DoS or execute arbitrary code'], ['1.0', '3.7', 1, 'CVE-2003-0693', 10.0, 'execute arbitrary code'], ['3.0', '3.6.1p2', 1, 'CVE-2003-0386', 7.5, 'bypass address restrictions for connection'], ['3.1p1', '3.6.1p1', 1, 'CVE-2003-0190', 5.0, 'discover valid usernames through different time delays'], ['3.2.2', '3.2.2', 1, 'CVE-2002-0765', 7.5, 'bypass authentication'], ['1.2.2', '3.3p1', 1, 'CVE-2002-0640', 10.0, 'execute arbitrary code'], ['1.2.2', '3.3p1', 1, 'CVE-2002-0639', 10.0, 'execute arbitrary code'], ['2.1', '3.2', 1, 'CVE-2002-0575', 7.5, 'privilege escalation'], ['2.1', '3.0.2p1', 2, 'CVE-2002-0083', 10.0, 'privilege escalation'], ['3.0', '3.0p1', 1, 'CVE-2001-1507', 7.5, 'bypass authentication'], ['1.2.3', '3.0.1p1', 5, 'CVE-2001-0872', 7.2, 'privilege escalation via crafted environment variables'], ['1.2.3', '2.1.1', 1, 'CVE-2001-0361', 4.0, 'recover plaintext from ciphertext'], ['1.2', '2.1', 1, 'CVE-2000-0525', 10.0, 'execute arbitrary code (improper privileges)']], 'PuTTY': [ ['0.54', '0.73', 2, 'CVE-2020-XXXX', 5.0, 'out of bounds memory read'], ['0.0', '0.72', 2, 'CVE-2019-17069', 5.0, 'potential DOS by remote SSHv1 server'], ['0.71', '0.72', 2, 'CVE-2019-17068', 5.0, 'xterm bracketed paste mode command injection'], ['0.52', '0.72', 2, 'CVE-2019-17067', 7.5, 'port rebinding weakness in port forward tunnel handling'], ['0.0', '0.71', 2, 'CVE-2019-XXXX', 5.0, 'undefined vulnerability in obsolete SSHv1 protocol handling'], ['0.0', '0.71', 6, 'CVE-2019-XXXX', 5.0, 'local privilege escalation in Pageant'], ['0.0', '0.70', 2, 'CVE-2019-9898', 7.5, 'potential recycling of random numbers'], ['0.0', '0.70', 2, 'CVE-2019-9897', 5.0, 'multiple denial-of-service issues from writing to the terminal'], ['0.0', '0.70', 6, 'CVE-2019-9896', 4.6, 'local application hijacking through malicious Windows help file'], ['0.0', '0.70', 2, 'CVE-2019-9894', 6.4, 'buffer overflow in RSA key exchange'], ['0.0', '0.69', 6, 'CVE-2016-6167', 4.4, 'local application hijacking through untrusted DLL loading'], ['0.0', '0.67', 2, 'CVE-2017-6542', 7.5, 'buffer overflow in UNIX client that can result in privilege escalation or denial-of-service'], ['0.0', '0.66', 2, 'CVE-2016-2563', 7.5, 'buffer overflow in SCP command-line utility'], ['0.0', '0.65', 2, 'CVE-2015-5309', 4.3, 'integer overflow in terminal-handling code'], ] } # type: Dict[str, List[List[Any]]] 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"']] } # type: Dict[str, List[List[Any]]] class Socket(ReadBuf, WriteBuf): class InsufficientReadException(Exception): pass SM_BANNER_SENT = 1 def __init__(self, host: Optional[str], port: int, ipvo: Optional[Sequence[int]] = None, timeout: Union[int, float] = 5, timeout_set: bool = False) -> None: super(SSH.Socket, self).__init__() self.__sock = None # type: Optional[socket.socket] self.__sock_map = {} # type: Dict[int, socket.socket] self.__block_size = 8 self.__state = 0 self.__header = [] # type: List[str] self.__banner = None # type: Optional[SSH.Banner] if host is None: raise ValueError('undefined host') nport = utils.parse_int(port) if nport < 1 or nport > 65535: raise ValueError('invalid port: {}'.format(port)) self.__host = host self.__port = nport if ipvo is not None: self.__ipvo = ipvo else: self.__ipvo = () self.__timeout = timeout self.__timeout_set = timeout_set self.client_host = None self.client_port = None def _resolve(self, ipvo: Sequence[int]) -> Iterable[Tuple[int, Tuple[Any, ...]]]: ipvo = tuple([x for x in utils.unique_seq(ipvo) if x in (4, 6)]) ipvo_len = len(ipvo) prefer_ipvo = ipvo_len > 0 prefer_ipv4 = prefer_ipvo and ipvo[0] == 4 if ipvo_len == 1: family = socket.AF_INET if ipvo[0] == 4 else socket.AF_INET6 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] {}'.format(e)) sys.exit(1) # Listens on a server socket and accepts one connection (used for # auditing client connections). def listen_and_accept(self) -> None: try: # Socket to listen on all IPv4 addresses. s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) s.bind(('0.0.0.0', self.__port)) s.listen() self.__sock_map[s.fileno()] = s except Exception: print("Warning: failed to listen on any IPv4 interfaces.") try: # Socket to listen on all IPv6 addresses. s = socket.socket(socket.AF_INET6, socket.SOCK_STREAM) s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) s.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, 1) s.bind(('::', self.__port)) s.listen() self.__sock_map[s.fileno()] = s except Exception: print("Warning: failed to listen on any IPv6 interfaces.") # 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!") sys.exit(-1) # Wait for an incoming connection. If a timeout was explicitly # set by the user, terminate when it elapses. fds = None time_elapsed = 0.0 interval = 1.0 while True: # Wait for a connection on either socket. fds = select.select(self.__sock_map.keys(), [], [], interval) time_elapsed += interval # We have incoming data on at least one of the sockets. if len(fds[0]) > 0: break if self.__timeout_set and time_elapsed >= self.__timeout: print("Timeout elapsed. Terminating...") sys.exit(-1) # Accept the connection. c, addr = self.__sock_map[fds[0][0]].accept() self.client_host = addr[0] self.client_port = addr[1] c.settimeout(self.__timeout) self.__sock = c def connect(self) -> None: err = None for af, addr in self._resolve(self.__ipvo): s = None try: s = socket.socket(af, socket.SOCK_STREAM) s.settimeout(self.__timeout) s.connect(addr) self.__sock = s return except socket.error as e: err = e self._close_socket(s) if err is None: errm = 'host {} has no DNS records'.format(self.__host) else: errt = (self.__host, self.__port, err) errm = 'cannot connect to {} port {}: {}'.format(*errt) out.fail('[exception] {}'.format(errm)) sys.exit(1) def get_banner(self, sshv: int = 2) -> Tuple[Optional['SSH.Banner'], List[str], Optional[str]]: if self.__sock is None: return self.__banner, self.__header, 'not connected' if self.__banner is not None: return self.__banner, self.__header, None banner = SSH_HEADER.format('1.5' if sshv == 1 else '2.0') if self.__state < self.SM_BANNER_SENT: self.send_banner(banner) s = 0 e = None while s >= 0: s, e = self.recv() if s < 0: continue while self.unread_len > 0: line = self.read_line() if len(line.strip()) == 0: continue self.__banner = SSH.Banner.parse(line) if self.__banner is not None: return self.__banner, self.__header, None self.__header.append(line) return self.__banner, self.__header, e def recv(self, size: int = 2048) -> Tuple[int, Optional[str]]: if self.__sock is None: return -1, 'not connected' try: data = self.__sock.recv(size) except socket.timeout: return -1, 'timed out' except socket.error as e: if e.args[0] in (errno.EAGAIN, errno.EWOULDBLOCK): return 0, 'retry' return -1, str(e.args[-1]) 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: bytes) -> Tuple[int, Optional[str]]: if self.__sock is None: return -1, 'not connected' try: self.__sock.send(data) return 0, None except socket.error as e: return -1, str(e.args[-1]) def send_banner(self, banner: str) -> None: 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: int) -> None: while self.unread_len < size: s, e = self.recv() if s < 0: raise SSH.Socket.InsufficientReadException(e) def read_packet(self, sshv: int = 2) -> Tuple[int, bytes]: 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].encode('utf-8') return -1, e def send_packet(self) -> Tuple[int, Optional[str]]: 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 is_connected(self) -> bool: """Returns true if this Socket is connected, False otherwise.""" return self.__sock is not None def close(self) -> None: self.__cleanup() self.reset() self.__state = 0 self.__header = [] self.__banner = None def _close_socket(self, s: Optional[socket.socket]) -> None: # pylint: disable=no-self-use try: if s is not None: s.shutdown(socket.SHUT_RDWR) s.close() # pragma: nocover except Exception: pass def __del__(self) -> None: self.__cleanup() def __cleanup(self) -> None: self._close_socket(self.__sock) for fd in self.__sock_map: self._close_socket(self.__sock_map[fd]) self.__sock = None class KexDH: # pragma: nocover def __init__(self, kex_name: str, hash_alg: str, g: int, p: int) -> None: self.__kex_name = kex_name self.__hash_alg = hash_alg self.__g = 0 self.__p = 0 self.__q = 0 self.__x = 0 self.__e = 0 self.set_params(g, p) self.__ed25519_pubkey = None # type: Optional[bytes] self.__hostkey_type = None # type: Optional[bytes] self.__hostkey_e = 0 self.__hostkey_n = 0 self.__hostkey_n_len = 0 # Length of the host key modulus. self.__ca_n_len = 0 # Length of the CA key modulus (if hostkey is a cert). def set_params(self, g: int, p: int) -> None: self.__g = g self.__p = p self.__q = (self.__p - 1) // 2 self.__x = 0 self.__e = 0 def send_init(self, s: SSH.Socket, init_msg: int = SSH.Protocol.MSG_KEXDH_INIT) -> None: r = random.SystemRandom() self.__x = r.randrange(2, self.__q) self.__e = pow(self.__g, self.__x, self.__p) s.write_byte(init_msg) s.write_mpint2(self.__e) s.send_packet() # Parse a KEXDH_REPLY or KEXDH_GEX_REPLY message from the server. This # contains the host key, among other things. Function returns the host # key blob (from which the fingerprint can be calculated). def recv_reply(self, s: 'SSH.Socket', parse_host_key_size: bool = True) -> Optional[bytes]: packet_type, payload = s.read_packet(2) # Skip any & all MSG_DEBUG messages. 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]: # 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: # A connection error occurred. We can't parse anything, so just # return. The host key modulus (and perhaps certificate modulus) # will remain at length 0. return None hostkey_len = 0 # pylint: disable=unused-variable hostkey_type_len = hostkey_e_len = 0 # pylint: disable=unused-variable key_id_len = principles_len = 0 # pylint: disable=unused-variable critical_options_len = extensions_len = 0 # pylint: disable=unused-variable nonce_len = ca_key_len = ca_key_type_len = 0 # pylint: disable=unused-variable ca_key_len = ca_key_type_len = ca_key_e_len = 0 # pylint: disable=unused-variable key_id = principles = None # pylint: disable=unused-variable critical_options = extensions = None # pylint: disable=unused-variable nonce = ca_key = ca_key_type = None # pylint: disable=unused-variable ca_key_e = ca_key_n = None # pylint: disable=unused-variable # Get the host key blob, F, and signature. ptr = 0 hostkey, hostkey_len, ptr = KexDH.__get_bytes(payload, ptr) # If we are not supposed to parse the host key size (i.e.: it is a type that is of fixed size such as ed25519), then stop here. if not parse_host_key_size: return hostkey _, _, ptr = KexDH.__get_bytes(payload, ptr) _, _, ptr = KexDH.__get_bytes(payload, ptr) # Now pick apart the host key blob. # Get the host key type (i.e.: 'ssh-rsa', 'ssh-ed25519', etc). ptr = 0 self.__hostkey_type, hostkey_type_len, ptr = KexDH.__get_bytes(hostkey, ptr) # If this is an RSA certificate, skip over the nonce. if self.__hostkey_type.startswith(b'ssh-rsa-cert-v0'): nonce, nonce_len, ptr = KexDH.__get_bytes(hostkey, ptr) # The public key exponent. hostkey_e, hostkey_e_len, ptr = KexDH.__get_bytes(hostkey, ptr) self.__hostkey_e = int(binascii.hexlify(hostkey_e), 16) # Here is the modulus size & actual modulus of the host key public key. hostkey_n, self.__hostkey_n_len, ptr = KexDH.__get_bytes(hostkey, ptr) self.__hostkey_n = int(binascii.hexlify(hostkey_n), 16) # If this is an RSA certificate, continue parsing to extract the CA # key. if self.__hostkey_type.startswith(b'ssh-rsa-cert-v0'): # Skip over the serial number. ptr += 8 # Get the certificate type. cert_type = int(binascii.hexlify(hostkey[ptr:ptr + 4]), 16) ptr += 4 # Only SSH2_CERT_TYPE_HOST (2) makes sense in this context. if cert_type == 2: # Skip the key ID (this is the serial number of the # certificate). key_id, key_id_len, ptr = KexDH.__get_bytes(hostkey, ptr) # The principles, which are... I don't know what. principles, principles_len, ptr = KexDH.__get_bytes(hostkey, ptr) # Skip over the timestamp that this certificate is valid after. ptr += 8 # Skip over the timestamp that this certificate is valid before. ptr += 8 # TODO: validate the principles, and time range. # The critical options. critical_options, critical_options_len, ptr = KexDH.__get_bytes(hostkey, ptr) # Certificate extensions. extensions, extensions_len, ptr = KexDH.__get_bytes(hostkey, ptr) # Another nonce. nonce, nonce_len, ptr = KexDH.__get_bytes(hostkey, ptr) # Finally, we get to the CA key. ca_key, ca_key_len, ptr = KexDH.__get_bytes(hostkey, ptr) # Last in the host key blob is the CA signature. It isn't # interesting to us, so we won't bother parsing any further. # The CA key has the modulus, however... ptr = 0 # 'ssh-rsa', 'rsa-sha2-256', etc. ca_key_type, ca_key_type_len, ptr = KexDH.__get_bytes(ca_key, ptr) # CA's public key exponent. ca_key_e, ca_key_e_len, ptr = KexDH.__get_bytes(ca_key, ptr) # CA's modulus. Bingo. ca_key_n, self.__ca_n_len, ptr = KexDH.__get_bytes(ca_key, ptr) return hostkey @staticmethod def __get_bytes(buf: bytes, ptr: int) -> Tuple[bytes, int, int]: num_bytes = struct.unpack('>I', buf[ptr:ptr + 4])[0] ptr += 4 return buf[ptr:ptr + num_bytes], num_bytes, ptr + num_bytes # Converts a modulus length in bytes to its size in bits, after some # possible adjustments. @staticmethod def __adjust_key_size(size: int) -> int: size = size * 8 # Actual keys are observed to be about 8 bits bigger than expected # (i.e.: 1024-bit keys have a 1032-bit modulus). Check if this is # the case, and subtract 8 if so. This simply improves readability # in the UI. if (size >> 3) % 2 != 0: size = size - 8 return size # Returns the size of the hostkey, in bits. def get_hostkey_size(self) -> int: return KexDH.__adjust_key_size(self.__hostkey_n_len) # Returns the size of the CA key, in bits. def get_ca_size(self) -> int: return KexDH.__adjust_key_size(self.__ca_n_len) # Returns the size of the DH modulus, in bits. def get_dh_modulus_size(self) -> int: # -2 to account for the '0b' prefix in the string. return len(bin(self.__p)) - 2 class KexGroup1(KexDH): # pragma: nocover def __init__(self) -> None: # rfc2409: second oakley group p = int('ffffffffffffffffc90fdaa22168c234c4c6628b80dc1cd129024e088a67cc74020bbea63b139b22514a08798e3404ddef9519b3cd3a431b302b0a6df25f14374fe1356d6d51c245e485b576625e7ec6f44c42e9a637ed6b0bff5cb6f406b7edee386bfb5a899fa5ae9f24117c4b1fe649286651ece65381ffffffffffffffff', 16) super(KexGroup1, self).__init__('KexGroup1', 'sha1', 2, p) class KexGroup14(KexDH): # pragma: nocover def __init__(self, hash_alg: str) -> None: # rfc3526: 2048-bit modp group p = int('ffffffffffffffffc90fdaa22168c234c4c6628b80dc1cd129024e088a67cc74020bbea63b139b22514a08798e3404ddef9519b3cd3a431b302b0a6df25f14374fe1356d6d51c245e485b576625e7ec6f44c42e9a637ed6b0bff5cb6f406b7edee386bfb5a899fa5ae9f24117c4b1fe649286651ece45b3dc2007cb8a163bf0598da48361c55d39a69163fa8fd24cf5f83655d23dca3ad961c62f356208552bb9ed529077096966d670c354e4abc9804f1746c08ca18217c32905e462e36ce3be39e772c180e86039b2783a2ec07a28fb5c55df06f4c52c9de2bcbf6955817183995497cea956ae515d2261898fa051015728e5a8aacaa68ffffffffffffffff', 16) super(KexGroup14, self).__init__('KexGroup14', hash_alg, 2, p) class KexGroup14_SHA1(KexGroup14): def __init__(self) -> None: super(KexGroup14_SHA1, self).__init__('sha1') class KexGroup14_SHA256(KexGroup14): def __init__(self) -> None: super(KexGroup14_SHA256, self).__init__('sha256') class KexGroup16_SHA512(KexDH): def __init__(self) -> None: # rfc3526: 4096-bit modp group p = int('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', 16) super(KexGroup16_SHA512, self).__init__('KexGroup16_SHA512', 'sha512', 2, p) class KexGroup18_SHA512(KexDH): def __init__(self) -> None: # rfc3526: 8192-bit modp group p = int('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', 16) super(KexGroup18_SHA512, self).__init__('KexGroup18_SHA512', 'sha512', 2, p) class KexCurve25519_SHA256(KexDH): def __init__(self) -> None: super(KexCurve25519_SHA256, self).__init__('KexCurve25519_SHA256', 'sha256', 0, 0) # To start an ED25519 kex, we simply send a random 256-bit number as the # public key. def send_init(self, s: 'SSH.Socket', init_msg: int = SSH.Protocol.MSG_KEXDH_INIT) -> None: self.__ed25519_pubkey = os.urandom(32) s.write_byte(init_msg) s.write_string(self.__ed25519_pubkey) s.send_packet() class KexNISTP256(KexDH): def __init__(self) -> None: super(KexNISTP256, self).__init__('KexNISTP256', 'sha256', 0, 0) # Because the server checks that the value sent here is valid (i.e.: it lies # on the curve, among other things), we would have to write a lot of code # or import an elliptic curve library in order to randomly generate a # valid elliptic point each time. Hence, we will simply send a static # value, which is enough for us to extract the server's host key. def send_init(self, s: 'SSH.Socket', init_msg: int = SSH.Protocol.MSG_KEXDH_INIT) -> None: s.write_byte(init_msg) s.write_string(b'\x04\x0b\x60\x44\x9f\x8a\x11\x9e\xc7\x81\x0c\xa9\x98\xfc\xb7\x90\xaa\x6b\x26\x8c\x12\x4a\xc0\x09\xbb\xdf\xc4\x2c\x4c\x2c\x99\xb6\xe1\x71\xa0\xd4\xb3\x62\x47\x74\xb3\x39\x0c\xf2\x88\x4a\x84\x6b\x3b\x15\x77\xa5\x77\xd2\xa9\xc9\x94\xf9\xd5\x66\x19\xcd\x02\x34\xd1') s.send_packet() class KexNISTP384(KexDH): def __init__(self) -> None: super(KexNISTP384, self).__init__('KexNISTP384', 'sha256', 0, 0) # See comment for KexNISTP256.send_init(). def send_init(self, s: 'SSH.Socket', init_msg: int = SSH.Protocol.MSG_KEXDH_INIT) -> None: s.write_byte(init_msg) s.write_string(b'\x04\xe2\x9b\x84\xce\xa1\x39\x50\xfe\x1e\xa3\x18\x70\x1c\xe2\x7a\xe4\xb5\x6f\xdf\x93\x9f\xd4\xf4\x08\xcc\x9b\x02\x10\xa4\xca\x77\x9c\x2e\x51\x44\x1d\x50\x7a\x65\x4e\x7e\x2f\x10\x2d\x2d\x4a\x32\xc9\x8e\x18\x75\x90\x6c\x19\x10\xda\xcc\xa8\xe9\xf4\xc4\x3a\x53\x80\x35\xf4\x97\x9c\x04\x16\xf9\x5a\xdc\xcc\x05\x94\x29\xfa\xc4\xd6\x87\x4e\x13\x21\xdb\x3d\x12\xac\xbd\x20\x3b\x60\xff\xe6\x58\x42') s.send_packet() class KexNISTP521(KexDH): def __init__(self) -> None: super(KexNISTP521, self).__init__('KexNISTP521', 'sha256', 0, 0) # See comment for KexNISTP256.send_init(). def send_init(self, s: 'SSH.Socket', init_msg: int = SSH.Protocol.MSG_KEXDH_INIT) -> None: s.write_byte(init_msg) s.write_string(b'\x04\x01\x02\x90\x29\xe9\x8f\xa8\x04\xaf\x1c\x00\xf9\xc6\x29\xc0\x39\x74\x8e\xea\x47\x7e\x7c\xf7\x15\x6e\x43\x3b\x59\x13\x53\x43\xb0\xae\x0b\xe7\xe6\x7c\x55\x73\x52\xa5\x2a\xc1\x42\xde\xfc\xf4\x1f\x8b\x5a\x8d\xfa\xcd\x0a\x65\x77\xa8\xce\x68\xd2\xc6\x26\xb5\x3f\xee\x4b\x01\x7b\xd2\x96\x23\x69\x53\xc7\x01\xe1\x0d\x39\xe9\x87\x49\x3b\xc8\xec\xda\x0c\xf9\xca\xad\x89\x42\x36\x6f\x93\x78\x78\x31\x55\x51\x09\x51\xc0\x96\xd7\xea\x61\xbf\xc2\x44\x08\x80\x43\xed\xc6\xbb\xfb\x94\xbd\xf8\xdf\x2b\xd8\x0b\x2e\x29\x1b\x8c\xc4\x8a\x04\x2d\x3a') s.send_packet() class KexGroupExchange(KexDH): def __init__(self, classname: str, hash_alg: str) -> None: super(KexGroupExchange, self).__init__(classname, hash_alg, 0, 0) def send_init(self, s: 'SSH.Socket', init_msg: int = SSH.Protocol.MSG_KEXDH_GEX_REQUEST) -> None: self.send_init_gex(s) # The group exchange starts with sending a message to the server with # the minimum, maximum, and preferred number of bits are for the DH group. # The server responds with a generator and prime modulus that matches that, # then the handshake continues on like a normal DH handshake (except the # SSH message types differ). def send_init_gex(self, s: 'SSH.Socket', minbits: int = 1024, prefbits: int = 2048, maxbits: int = 8192) -> None: # Send the initial group exchange request. Tell the server what range # of modulus sizes we will accept, along with our preference. s.write_byte(SSH.Protocol.MSG_KEXDH_GEX_REQUEST) s.write_int(minbits) s.write_int(prefbits) s.write_int(maxbits) 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): # 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)) # Skip any & all MSG_DEBUG messages. while packet_type == SSH.Protocol.MSG_DEBUG: packet_type, payload = s.read_packet(2) # Parse the modulus (p) and generator (g) values from the server. ptr = 0 p_len = struct.unpack('>I', payload[ptr:ptr + 4])[0] ptr += 4 p = int(binascii.hexlify(payload[ptr:ptr + p_len]), 16) ptr += p_len g_len = struct.unpack('>I', payload[ptr:ptr + 4])[0] ptr += 4 g = int(binascii.hexlify(payload[ptr:ptr + g_len]), 16) ptr += g_len # Now that we got the generator and modulus, perform the DH exchange # like usual. super(KexGroupExchange, self).set_params(g, p) super(KexGroupExchange, self).send_init(s, SSH.Protocol.MSG_KEXDH_GEX_INIT) class KexGroupExchange_SHA1(KexGroupExchange): def __init__(self) -> None: super(KexGroupExchange_SHA1, self).__init__('KexGroupExchange_SHA1', 'sha1') class KexGroupExchange_SHA256(KexGroupExchange): def __init__(self) -> None: super(KexGroupExchange_SHA256, self).__init__('KexGroupExchange_SHA256', 'sha256') def output_algorithms(title: str, alg_db: Dict[str, Dict[str, List[List[Optional[str]]]]], alg_type: str, algorithms: List[str], unknown_algs: List[str], is_json_output: bool, program_retval: int, maxlen: int = 0, alg_sizes: Optional[Dict[str, Tuple[int, int]]] = None) -> int: # pylint: disable=too-many-arguments with OutputBuffer() as obuf: for algorithm in algorithms: program_retval = output_algorithm(alg_db, alg_type, algorithm, unknown_algs, program_retval, maxlen, alg_sizes) if len(obuf) > 0 and not is_json_output: out.head('# ' + title) obuf.flush() out.sep() return program_retval def output_algorithm(alg_db: Dict[str, Dict[str, List[List[Optional[str]]]]], alg_type: str, alg_name: str, unknown_algs: List[str], program_retval: int, alg_max_len: int = 0, alg_sizes: Optional[Dict[str, Tuple[int, int]]] = None) -> int: 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)) # If this is an RSA host key or DH GEX, append the size to its name and fix # the padding. alg_name_with_size = None if (alg_sizes is not None) and (alg_name in alg_sizes): hostkey_size, ca_size = alg_sizes[alg_name] if ca_size > 0: alg_name_with_size = '%s (%d-bit cert/%d-bit CA)' % (alg_name, hostkey_size, ca_size) padding = padding[0:-15] else: alg_name_with_size = '%s (%d-bit)' % (alg_name, hostkey_size) padding = padding[0:-11] texts = [] if len(alg_name.strip()) == 0: return program_retval alg_name_native = utils.to_text(alg_name) if alg_name_native in alg_db[alg_type]: alg_desc = alg_db[alg_type][alg_name_native] ldesc = len(alg_desc) for idx, level in enumerate(['fail', 'warn', 'info']): if level == 'info': versions = alg_desc[0] since_text = SSH.Algorithm.get_since_text(versions) if since_text is not None and len(since_text) > 0: texts.append((level, since_text)) idx = idx + 1 if ldesc > idx: for t in alg_desc[idx]: if t is None: continue texts.append((level, t)) if len(texts) == 0: texts.append(('info', '')) else: texts.append(('warn', 'unknown algorithm')) unknown_algs.append(alg_name) alg_name = alg_name_with_size if alg_name_with_size is not None else alg_name first = True for level, text in texts: if level == 'fail': program_retval = PROGRAM_RETVAL_FAILURE elif level == 'warn' and program_retval != PROGRAM_RETVAL_FAILURE: # If a failure was found previously, don't downgrade to warning. program_retval = PROGRAM_RETVAL_WARNING f = getattr(out, level) comment = (padding + ' -- [' + level + '] ' + text) if text != '' else '' if first: if first and level == 'info': f = out.good f(prefix + alg_name + comment) first = False else: # pylint: disable=else-if-used if out.verbose: f(prefix + alg_name + comment) elif text != '': comment = (padding + ' `- [' + level + '] ' + text) f(' ' * len(prefix + alg_name) + comment) return program_retval def output_compatibility(algs: SSH.Algorithms, client_audit: bool, for_server: bool = True) -> None: # Don't output any compatibility info if we're doing a client audit. if client_audit: return ssh_timeframe = algs.get_ssh_timeframe(for_server) comp_text = [] for ssh_prod in [SSH.Product.OpenSSH, SSH.Product.DropbearSSH]: if ssh_prod not in ssh_timeframe: continue v_from = ssh_timeframe.get_from(ssh_prod, for_server) v_till = ssh_timeframe.get_till(ssh_prod, for_server) if v_from is None: continue if v_till is None: comp_text.append('{} {}+'.format(ssh_prod, v_from)) elif v_from == v_till: comp_text.append('{} {}'.format(ssh_prod, v_from)) else: software = SSH.Software(None, ssh_prod, v_from, None, None) if software.compare_version(v_till) > 0: tfmt = '{0} {1}+ (some functionality from {2})' else: tfmt = '{0} {1}-{2}' comp_text.append(tfmt.format(ssh_prod, v_from, v_till)) if len(comp_text) > 0: out.good('(gen) compatibility: ' + ', '.join(comp_text)) def output_security_sub(sub: str, software: Optional[SSH.Software], client_audit: bool, padlen: int) -> None: 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 = '' # type: str vtill = '' # type: str vfrom, vtill = line[0:2] if not software.between_versions(vfrom, vtill): continue target = 0 # type: int name = '' # type: str target, name = line[2:4] is_server = target & 1 == 1 is_client = target & 2 == 2 # is_local = target & 4 == 4 # If this security entry applies only to servers, but we're testing a client, then skip it. Similarly, skip entries that apply only to clients, but we're testing a server. if (is_server and not is_client and client_audit) or (is_client and not is_server and not client_audit): continue p = '' if out.batch else ' ' * (padlen - len(name)) if sub == 'cve': cvss = 0.0 # type: float descr = '' # type: str cvss, descr = line[4:6] # Critical CVSS scores (>= 8.0) are printed as a fail, otherwise they are printed as a warning. out_func = out.warn if cvss >= 8.0: out_func = out.fail out_func('(cve) {}{} -- (CVSSv2: {}) {}'.format(name, p, cvss, descr)) else: descr = line[4] out.fail('(sec) {}{} -- {}'.format(name, p, descr)) def output_security(banner: Optional[SSH.Banner], client_audit: bool, padlen: int, is_json_output: bool) -> None: with OutputBuffer() as obuf: if banner is not None: software = SSH.Software.parse(banner) output_security_sub('cve', software, client_audit, padlen) output_security_sub('txt', software, client_audit, padlen) if len(obuf) > 0 and not is_json_output: out.head('# security') obuf.flush() out.sep() def output_fingerprints(algs: SSH.Algorithms, is_json_output: bool, sha256: bool = True) -> None: with OutputBuffer() as obuf: fps = [] if algs.ssh1kex is not None: name = 'ssh-rsa1' fp = SSH.Fingerprint(algs.ssh1kex.host_key_fingerprint_data) # bits = algs.ssh1kex.host_key_bits fps.append((name, fp)) if algs.ssh2kex is not None: host_keys = algs.ssh2kex.host_keys() for host_key_type in algs.ssh2kex.host_keys(): if host_keys[host_key_type] is None: continue fp = SSH.Fingerprint(host_keys[host_key_type]) # Workaround for Python's order-indifference in dicts. We might get a random RSA type (ssh-rsa, rsa-sha2-256, or rsa-sha2-512), so running the tool against the same server three times may give three different host key types here. So if we have any RSA type, we will simply hard-code it to 'ssh-rsa'. if host_key_type in SSH2.HostKeyTest.RSA_FAMILY: host_key_type = 'ssh-rsa' # Skip over certificate host types (or we would return invalid fingerprints). if '-cert-' not in host_key_type: fps.append((host_key_type, fp)) # Similarly, the host keys can be processed in random order due to Python's order-indifference in dicts. So we sort this list before printing; this makes automated testing possible. fps = sorted(fps) for fpp in fps: name, fp = fpp fpo = 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, fpo)) out.good('(fin) {}: {}'.format(name, fpo)) if len(obuf) > 0 and not is_json_output: out.head('# fingerprints') obuf.flush() out.sep() # Returns True if no warnings or failures encountered in configuration. def output_recommendations(algs: SSH.Algorithms, software: Optional[SSH.Software], is_json_output: bool, padlen: int = 0) -> bool: ret = True # PuTTY's algorithms cannot be modified, so there's no point in issuing recommendations. if (software is not None) and (software.product == SSH.Product.PuTTY): max_vuln_version = 0.0 max_cvssv2_severity = 0.0 # Search the CVE database for the most recent vulnerable version and the max CVSSv2 score. for cve_list in SSH.Security.CVE['PuTTY']: vuln_version = float(cve_list[1]) cvssv2_severity = cve_list[4] if vuln_version > max_vuln_version: max_vuln_version = vuln_version if cvssv2_severity > max_cvssv2_severity: max_cvssv2_severity = cvssv2_severity fn = out.warn if max_cvssv2_severity > 8.0: fn = out.fail # Assuming that PuTTY versions will always increment by 0.01, we can calculate the first safe version by adding 0.01 to the latest vulnerable version. current_version = float(software.version) upgrade_to_version = max_vuln_version + 0.01 if current_version < upgrade_to_version: out.head('# recommendations') fn('(rec) Upgrade to PuTTY v%.2f' % upgrade_to_version) out.sep() ret = False return ret for_server = True with OutputBuffer() as obuf: software, alg_rec = algs.get_recommendations(software, for_server) 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', 'chg']: 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)) chg_additional_info = '' if action == 'del': an, sg, fn = 'remove', '-', out.warn ret = False if alg_rec[sshv][alg_type][action][name] >= 10: fn = out.fail elif action == 'add': an, sg, fn = 'append', '+', out.good elif action == 'chg': an, sg, fn = 'change', '!', out.fail ret = False chg_additional_info = ' (increase modulus size to 2048 bits or larger)' b = '(SSH{})'.format(sshv) if sshv == 1 else '' fm = '(rec) {0}{1}{2}-- {3} algorithm to {4}{5} {6}' fn(fm.format(sg, name, p, alg_type, an, chg_additional_info, b)) if len(obuf) > 0 and not is_json_output: if software is not None: title = '(for {})'.format(software.display(False)) else: title = '' out.head('# algorithm recommendations {}'.format(title)) obuf.flush(True) # Sort the output so that it is always stable (needed for repeatable testing). out.sep() return ret # Output additional information & notes. def output_info(software: Optional['SSH.Software'], client_audit: bool, any_problems: bool, is_json_output: bool) -> None: 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): out.warn('(nfo) PuTTY does not have the option of restricting any algorithms during the SSH handshake.') # If any warnings or failures were given, print a link to the hardening guides. if any_problems: out.warn('(nfo) For hardening guides on common OSes, please see: ') if len(obuf) > 0 and not is_json_output: out.head('# additional info') obuf.flush() out.sep() # Returns a PROGRAM_RETVAL_* flag to denote if any failures or warnings were encountered. def output(aconf: AuditConf, banner: Optional[SSH.Banner], header: List[str], client_host: Optional[str] = None, kex: Optional[SSH2.Kex] = None, pkm: Optional[SSH1.PublicKeyMessage] = None, print_target: bool = False) -> int: program_retval = PROGRAM_RETVAL_GOOD client_audit = client_host is not None # If set, this is a client audit. sshv = 1 if pkm is not None else 2 algs = SSH.Algorithms(pkm, kex) with OutputBuffer() as obuf: if print_target: host = aconf.host # Print the port if it's not the default of 22. if aconf.port != 22: # Check if this is an IPv6 address, as that is printed in a different format. is_ipv6 = True try: ipaddress.IPv6Address(aconf.host) except ipaddress.AddressValueError: is_ipv6 = False if is_ipv6: host = '[%s]:%d' % (aconf.host, aconf.port) else: host = '%s:%d' % (aconf.host, aconf.port) out.good('(gen) target: {}'. format(host)) if client_audit: out.good('(gen) client IP: {}'.format(client_host)) if len(header) > 0: out.info('(gen) header: ' + '\n'.join(header)) if banner is not None: out.good('(gen) banner: {}'.format(banner)) if not banner.valid_ascii: # NOTE: RFC 4253, Section 4.2 out.warn('(gen) banner contains non-printable ASCII') 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: {}'.format(software)) else: software = None output_compatibility(algs, client_audit) if kex is not None: compressions = [x for x in kex.server.compression if x != 'none'] if len(compressions) > 0: cmptxt = 'enabled ({})'.format(', '.join(compressions)) else: cmptxt = 'disabled' out.good('(gen) compression: {}'.format(cmptxt)) if len(obuf) > 0 and not aconf.json: # Print output when it exists and JSON output isn't requested. out.head('# general') obuf.flush() out.sep() maxlen = algs.maxlen + 1 output_security(banner, client_audit, maxlen, aconf.json) # Filled in by output_algorithms() with unidentified algs. unknown_algorithms = [] # type: List[str] if pkm is not None: adb = SSH1.KexDB.ALGORITHMS ciphers = pkm.supported_ciphers auths = pkm.supported_authentications title, atype = 'SSH1 host-key algorithms', 'key' program_retval = output_algorithms(title, adb, atype, ['ssh-rsa1'], unknown_algorithms, aconf.json, program_retval, maxlen) title, atype = 'SSH1 encryption algorithms (ciphers)', 'enc' program_retval = output_algorithms(title, adb, atype, ciphers, unknown_algorithms, aconf.json, program_retval, maxlen) title, atype = 'SSH1 authentication types', 'aut' program_retval = output_algorithms(title, adb, atype, auths, unknown_algorithms, aconf.json, program_retval, maxlen) if kex is not None: adb = SSH2.KexDB.ALGORITHMS title, atype = 'key exchange algorithms', 'kex' program_retval = output_algorithms(title, adb, atype, kex.kex_algorithms, unknown_algorithms, aconf.json, program_retval, maxlen, kex.dh_modulus_sizes()) title, atype = 'host-key algorithms', 'key' program_retval = output_algorithms(title, adb, atype, kex.key_algorithms, unknown_algorithms, aconf.json, program_retval, maxlen, kex.rsa_key_sizes()) title, atype = 'encryption algorithms (ciphers)', 'enc' program_retval = output_algorithms(title, adb, atype, kex.server.encryption, unknown_algorithms, aconf.json, program_retval, maxlen) title, atype = 'message authentication code algorithms', 'mac' program_retval = output_algorithms(title, adb, atype, kex.server.mac, unknown_algorithms, aconf.json, program_retval, maxlen) output_fingerprints(algs, aconf.json, True) perfect_config = output_recommendations(algs, software, aconf.json, maxlen) output_info(software, client_audit, not perfect_config, aconf.json) if aconf.json: print(json.dumps(build_struct(banner, kex=kex, client_host=client_host), sort_keys=True), end='' if len(aconf.target_list) > 0 else "\n") # Print the JSON of the audit info. Skip the newline at the end if multiple targets were given (since each audit dump will go into its own list entry). elif len(unknown_algorithms) > 0: # If we encountered any unknown algorithms, ask the user to report them. 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 .\n" % ','.join(unknown_algorithms)) return program_retval def evaluate_policy(aconf: AuditConf, banner: Optional['SSH.Banner'], kex: Optional['SSH2.Kex'] = None) -> bool: if aconf.policy is None: raise RuntimeError('Internal error: cannot evaluate against null Policy!') passed, errors = aconf.policy.evaluate(banner, kex) if aconf.json: json_struct = {'host': aconf.host, 'policy': aconf.policy.get_name_and_version(), 'passed': passed, 'errors': errors} print(json.dumps(json_struct, sort_keys=True)) else: print("Host: %s" % aconf.host) print("Policy: %s" % aconf.policy.get_name_and_version()) print("Result: ", end='') if passed: out.good("✔ Passed") else: out.fail("❌ Failed!") out.warn("\nErrors:\n * %s" % '\n * '.join(errors)) return passed def make_policy(aconf: AuditConf, banner: Optional['SSH.Banner'], kex: Optional['SSH2.Kex']) -> None: policy_data = Policy.create(aconf.host, banner, kex) if aconf.policy_file is None: raise RuntimeError('Internal error: cannot write policy file since filename is None!') # Open with mode 'x' (creates the file, or fails if it already exist). succeeded = True try: with open(aconf.policy_file, 'x') as f: f.write(policy_data) except FileExistsError: succeeded = False if succeeded: print("Wrote policy to %s. Customize as necessary, then run a policy scan with -P option." % aconf.policy_file) else: print("Error: file already exists: %s" % aconf.policy_file) class Utils: @classmethod def _type_err(cls, v: Any, target: str) -> TypeError: return TypeError('cannot convert {} to {}'.format(type(v), target)) @classmethod def to_bytes(cls, v: Union[bytes, str], enc: str = 'utf-8') -> bytes: if isinstance(v, bytes): return v elif isinstance(v, str): return v.encode(enc) raise cls._type_err(v, 'bytes') @classmethod def to_text(cls, v: Union[str, bytes], enc: str = 'utf-8') -> str: if isinstance(v, str): return v elif isinstance(v, bytes): return v.decode(enc) raise cls._type_err(v, 'unicode text') @classmethod def _is_ascii(cls, v: str, char_filter: Callable[[int], bool] = lambda x: x <= 127) -> bool: r = False if isinstance(v, str): for c in v: i = cls.ctoi(c) if not char_filter(i): return r r = True return r @classmethod def _to_ascii(cls, v: str, char_filter: Callable[[int], bool] = lambda x: x <= 127, errors: str = 'replace') -> str: if isinstance(v, str): r = bytearray() for c in v: i = cls.ctoi(c) if char_filter(i): r.append(i) else: if errors == 'ignore': continue r.append(63) return cls.to_text(r.decode('ascii')) raise cls._type_err(v, 'ascii') @classmethod def is_ascii(cls, v: str) -> bool: return cls._is_ascii(v) @classmethod def to_ascii(cls, v: str, errors: str = 'replace') -> str: return cls._to_ascii(v, errors=errors) @classmethod def is_print_ascii(cls, v: str) -> bool: return cls._is_ascii(v, lambda x: 126 >= x >= 32) @classmethod def to_print_ascii(cls, v: str, errors: str = 'replace') -> str: return cls._to_ascii(v, lambda x: 126 >= x >= 32, errors) @classmethod def unique_seq(cls, seq: Sequence[Any]) -> Sequence[Any]: seen = set() # type: Set[Any] def _seen_add(x: 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)] @classmethod def ctoi(cls, c: Union[str, int]) -> int: if isinstance(c, str): return ord(c[0]) else: return c @staticmethod def parse_int(v: Any) -> int: try: return int(v) except Exception: # pylint: disable=bare-except return 0 @staticmethod def parse_float(v: Any) -> float: try: return float(v) except Exception: # pylint: disable=bare-except return -1.0 @staticmethod def parse_host_and_port(host_and_port: str) -> Tuple[str, int]: '''Parses a string into a tuple of its host and port. The port is 0 if not specified.''' host = host_and_port port = 0 mx = re.match(r'^\[([^\]]+)\](?::(\d+))?$', host_and_port) if mx is not None: host = mx.group(1) port_str = mx.group(2) if port_str is not None: port = int(port_str) else: s = host_and_port.split(':') if len(s) == 2: host = s[0] if len(s[1]) > 0: port = int(s[1]) return host, port def build_struct(banner: Optional['SSH.Banner'], kex: Optional['SSH2.Kex'] = None, pkm: Optional['SSH1.PublicKeyMessage'] = None, client_host: Optional[str] = None) -> Any: banner_str = '' banner_protocol = None banner_software = None banner_comments = None if banner is not None: banner_str = str(banner) banner_protocol = banner.protocol banner_software = banner.software banner_comments = banner.comments res = { "banner": { "raw": banner_str, "protocol": banner_protocol, "software": banner_software, "comments": banner_comments, }, } # type: Any if client_host is not None: res['client_ip'] = client_host if kex is not None: res['compression'] = kex.server.compression res['kex'] = [] alg_sizes = kex.dh_modulus_sizes() for algorithm in kex.kex_algorithms: entry = { 'algorithm': algorithm, } # type: Any if algorithm in alg_sizes: hostkey_size, ca_size = alg_sizes[algorithm] entry['keysize'] = hostkey_size if ca_size > 0: entry['casize'] = ca_size res['kex'].append(entry) res['key'] = [] alg_sizes = kex.rsa_key_sizes() for algorithm in kex.key_algorithms: entry = { 'algorithm': algorithm, } if algorithm in alg_sizes: hostkey_size, ca_size = alg_sizes[algorithm] entry['keysize'] = hostkey_size if ca_size > 0: entry['casize'] = ca_size res['key'].append(entry) res['enc'] = kex.server.encryption res['mac'] = kex.server.mac res['fingerprints'] = [] host_keys = kex.host_keys() # Normalize all RSA key types to 'ssh-rsa'. Otherwise, due to Python's order-indifference dictionary types, we would iterate key types in unpredictable orders, which interferes with the docker testing framework (i.e.: tests would fail because elements are reported out of order, even though the output is semantically the same). for host_key_type in list(host_keys.keys())[:]: if host_key_type in SSH2.HostKeyTest.RSA_FAMILY: val = host_keys[host_key_type] del host_keys[host_key_type] host_keys['ssh-rsa'] = val for host_key_type in sorted(host_keys): if host_keys[host_key_type] is None: continue fp = SSH.Fingerprint(host_keys[host_key_type]) # Skip over certificate host types (or we would return invalid fingerprints). if '-cert-' in host_key_type: continue entry = { 'type': host_key_type, 'fp': fp.sha256, } res['fingerprints'].append(entry) else: pkm_supported_ciphers = None pkm_supported_authentications = None pkm_fp = None if pkm is not None: pkm_supported_ciphers = pkm.supported_ciphers pkm_supported_authentications = pkm.supported_authentications pkm_fp = SSH.Fingerprint(pkm.host_key_fingerprint_data).sha256 res['key'] = ['ssh-rsa1'] res['enc'] = pkm_supported_ciphers res['aut'] = pkm_supported_authentications res['fingerprints'] = [{ 'type': 'ssh-rsa1', 'fp': pkm_fp, }] return res # Returns one of the PROGRAM_RETVAL_* flags. def audit(aconf: AuditConf, sshv: Optional[int] = None, print_target: bool = False) -> int: program_retval = PROGRAM_RETVAL_GOOD out.batch = aconf.batch out.verbose = aconf.verbose out.level = aconf.level out.use_colors = aconf.colors s = SSH.Socket(aconf.host, aconf.port, aconf.ipvo, aconf.timeout, aconf.timeout_set) if aconf.client_audit: s.listen_and_accept() else: s.connect() if sshv is None: sshv = 2 if aconf.ssh2 else 1 err = None banner, header, err = s.get_banner(sshv) if banner is None: if err is None: err = '[exception] did not receive banner.' else: err = '[exception] did not receive banner: {}'.format(err) if err is None: packet_type, payload = s.read_packet(sshv) if packet_type < 0: try: if len(payload) > 0: payload_txt = payload.decode('utf-8') else: payload_txt = u'empty' except UnicodeDecodeError: payload_txt = u'"{}"'.format(repr(payload).lstrip('b')[1:-1]) if payload_txt == u'Protocol major versions differ.': if sshv == 2 and aconf.ssh1: return audit(aconf, 1) err = '[exception] error reading packet ({})'.format(payload_txt) else: err_pair = None if sshv == 1 and packet_type != SSH.Protocol.SMSG_PUBLIC_KEY: err_pair = ('SMSG_PUBLIC_KEY', SSH.Protocol.SMSG_PUBLIC_KEY) elif sshv == 2 and packet_type != SSH.Protocol.MSG_KEXINIT: err_pair = ('MSG_KEXINIT', SSH.Protocol.MSG_KEXINIT) if err_pair is not None: fmt = '[exception] did not receive {0} ({1}), ' + \ 'instead received unknown message ({2})' err = fmt.format(err_pair[0], err_pair[1], packet_type) if err is not None: output(aconf, banner, header) out.fail(err) return PROGRAM_RETVAL_CONNECTION_ERROR if sshv == 1: program_retval = output(aconf, banner, header, pkm=SSH1.PublicKeyMessage.parse(payload)) elif sshv == 2: kex = SSH2.Kex.parse(payload) if aconf.client_audit is False: SSH2.HostKeyTest.run(s, kex) SSH2.GEXTest.run(s, kex) # This is a standard audit scan. if (aconf.policy is None) and (aconf.make_policy is False): program_retval = output(aconf, banner, header, client_host=s.client_host, kex=kex, print_target=print_target) # This is a policy test. elif (aconf.policy is not None) and (aconf.make_policy is False): program_retval = PROGRAM_RETVAL_GOOD if evaluate_policy(aconf, banner, kex=kex) else PROGRAM_RETVAL_FAILURE # A new policy should be made from this scan. elif (aconf.policy is None) and (aconf.make_policy is True): make_policy(aconf, banner, kex=kex) else: raise RuntimeError('Internal error while handling output: %r %r' % (aconf.policy is None, aconf.make_policy)) return program_retval utils = Utils() out = Output() def main() -> int: aconf = AuditConf.from_cmdline(sys.argv[1:], usage) # If multiple targets were specified... if len(aconf.target_list) > 0: ret = PROGRAM_RETVAL_GOOD # If JSON output is desired, each target's results will be reported in its own list entry. if aconf.json: print('[', end='') # Loop through each target in the list. for i, target in enumerate(aconf.target_list): aconf.host, port = Utils.parse_host_and_port(target) if port == 0: port = 22 aconf.port = port new_ret = audit(aconf, print_target=True) # Set the return value only if an unknown error occurred, a failure occurred, or if a warning occurred and the previous value was good. if (new_ret == PROGRAM_RETVAL_UNKNOWN_ERROR) or (new_ret == PROGRAM_RETVAL_FAILURE) or ((new_ret == PROGRAM_RETVAL_WARNING) and (ret == PROGRAM_RETVAL_GOOD)): ret = new_ret # Don't print a delimiter after the last target was handled. if i + 1 != len(aconf.target_list): if aconf.json: print(", ", end='') else: print(("-" * 80) + "\n") if aconf.json: print(']') return ret else: return audit(aconf) if __name__ == '__main__': # pragma: nocover exit_code = PROGRAM_RETVAL_GOOD try: exit_code = main() except Exception: exit_code = PROGRAM_RETVAL_UNKNOWN_ERROR print(traceback.format_exc()) sys.exit(exit_code)