# Copyright 2016(c) Hubert Kario # This work is released under the Mozilla Public License Version 2.0 """tlslite-ng based server configuration (and bug) scanner.""" from __future__ import print_function from tlslite.messages import ClientHello, ServerHello, ServerHelloDone, Alert from tlslite.constants import CipherSuite, \ AlertLevel import sys import json import getopt import itertools from cscan.scanner import Scanner from cscan.config import Firefox_42 from cscan.modifiers import set_hello_version def scan_with_config(host, port, conf, hostname, __sentry=None, __cache={}): """Connect to server and return set of exchanged messages.""" assert __sentry is None key = (host, port, conf, hostname) if key in __cache: if verbose and not json_out: print(":", end='') return __cache[key] scanner = Scanner(conf, host, port, hostname) ret = scanner.scan() __cache[key] = ret if verbose and not json_out: print(".", end='') sys.stdout.flush() return ret def simple_inspector(result): """ Perform simple check to see if connection was successful. Returns True is connection was successful, server replied with ServerHello and ServerHelloDone messages, and the cipher selected was present in ciphers advertised by client, False otherwise """ if any(isinstance(x, ServerHelloDone) for x in result): ch = next((x for x in result if isinstance(x, ClientHello)), None) sh = next((x for x in result if isinstance(x, ServerHello)), None) if ch and sh: if sh.cipher_suite not in ch.cipher_suites: # FAILURE cipher suite mismatch return False return True # incomplete response or error return False def verbose_inspector(desc, result): """Describe the connection result in human-readable form.""" ret = "{0}:".format(desc) if any(isinstance(x, ServerHelloDone) for x in result): ch = next((x for x in result if isinstance(x, ClientHello)), None) sh = next((x for x in result if isinstance(x, ServerHello)), None) if sh and ch: if sh.cipher_suite not in ch.cipher_suites: ret += " FAILURE cipher suite mismatch" return ret name = CipherSuite.ietfNames[sh.cipher_suite] \ if sh.cipher_suite in CipherSuite.ietfNames \ else hex(sh.cipher_suite) ret += " ok: {0}, {1}".format(sh.server_version, name) return ret ret += " FAILURE " errors = [] for msg in result: if isinstance(msg, ClientHello): continue # check if returned message supports custom formatting if msg.__class__.__format__ is not object.__format__: errors += ["{:vxm}".format(msg)] else: errors += [repr(msg)] # skip printing close errors after fatal alerts, they are expected if isinstance(msg, Alert) and msg.level == AlertLevel.fatal: break ret += "\n".join(errors) return ret configs = {} def load_configs(): """Load known client configurations for later use in scanning.""" base_configs = [Firefox_42] for conf in base_configs: for version in ((3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3, 254)): if conf().version != version: # just changed version gen = set_hello_version(conf(), version) if gen.record_version > version: gen.record_version = version configs[gen.name] = gen # Firefox 42 configs gen = Firefox_42() configs[gen.name] = gen def scan_TLS_intolerancies(host, port, hostname): """Look for intolerancies (version, extensions, ...) in a TLS server.""" results = {} def result_iterator(predicate): """ Selecting iterator over cached results. Looks for matching result from already performed scans """ return (not simple_inspector(results[name]) for name in results if predicate(configs[name])) def result_cache(name, conf): """Perform scan if config is not in results, caches result.""" return results[name] if name in results \ else results.setdefault(name, scan_with_config(host, port, conf, hostname)) def conf_iterator(predicate): """ Caching, selecting iterator over configs. Returns an iterator that will go over configs that match the provided predicate (a function that returns true or false depending if given config is ok for test at hand) while saving the results to the cache/verbose `results` log/dictionary The iterator returns False for every connection that succeeded (meaning the server is NOT intolerant to config and True to mean that server IS intolerant to config. """ scan_iter = (not simple_inspector(result_cache(name, conf)) for name, conf in configs.items() if predicate(conf)) return itertools.chain(result_iterator(predicate), scan_iter) host_up = not all(conf_iterator(lambda conf: True)) intolerancies = {} if not host_up: if json_out: print(json.dumps(intolerancies)) else: print("Host does not seem to support SSL or TLS protocol") return intolerancies["SSL 3.254"] = all(conf_iterator(lambda conf: conf.version == (3, 254))) intolerancies["TLS 1.4"] = all(conf_iterator(lambda conf: conf.version == (3, 5))) intolerancies["TLS 1.3"] = all(conf_iterator(lambda conf: conf.version == (3, 4))) intolerancies["TLS 1.2"] = all(conf_iterator(lambda conf: conf.version == (3, 3))) intolerancies["TLS 1.1"] = all(conf_iterator(lambda conf: conf.version == (3, 2))) intolerancies["TLS 1.0"] = all(conf_iterator(lambda conf: conf.version == (3, 1))) if json_out: print(json.dumps(intolerancies)) else: if not no_header: if verbose: print() print("Host {0}:{1} scan complete".format(host, port)) if hostname: print("SNI hostname used: {0}".format(hostname)) if verbose: print() print("Individual probe results:") for desc, ret in sorted(results.items()): print(verbose_inspector(desc, ret)) print() print("Intolerance to:") for intolerance, value in sorted(intolerancies.items()): print(" {0:20}: {1}".format(intolerance, "PRESENT" if value else "absent")) def single_probe(name): """Run a single probe against a server, print result.""" print(verbose_inspector(name, scan_with_config(host, port, configs[name], hostname))) def usage(): """Print usage information.""" print("./cscan.py [ARGUMENTS] host[:port] [SNI-HOST-NAME]") print() print("-l, --list List probe names") print("-p name, --probe Run just a single probe") print("-j, --json Output in JSON format") print("-v, --verbose Use verbose output") if __name__ == "__main__": try: opts, args = getopt.getopt(sys.argv[1:], "jvhlp:", ["json", "verbose", "help", "list", "probe=", "no-header"]) except getopt.GetoptError as err: print(err) usage() sys.exit(2) json_out = False verbose = False list_probes = False run_probe = None no_header = False for opt, arg in opts: if opt in ('-j', '--json'): json_out = True elif opt in ('-v', '--verbose'): verbose = True elif opt in ('-h', '--help'): usage() sys.exit(0) elif opt in ('-l', '--list'): list_probes = True elif opt in ('-p', '--probe'): run_probe = arg elif opt in ('--no-header', ): no_header = True else: raise AssertionError("Unknown option {0}".format(opt)) if len(args) > 2: print("Too many arguments") usage() sys.exit(2) load_configs() if list_probes: for desc, ret in sorted(configs.items()): print("{0}: {1}".format(desc, ret.__doc__)) sys.exit(0) hostname = None if len(args) == 2: hostname = args[1] hostaddr = args[0].split(":") if len(hostaddr) > 1: host, port = hostaddr else: host = hostaddr[0] port = 443 if run_probe: single_probe(run_probe) else: scan_TLS_intolerancies(host, port, hostname)