mirror of
https://github.com/mozilla/cipherscan.git
synced 2024-11-21 22:13:40 +01:00
size intolerance checks
since TLSv1.3 client hello's will include initial client key share, verify that the server is able to accept and process big client hello messages
This commit is contained in:
parent
88ae052f8e
commit
1f26852b29
77
cscan.py
77
cscan.py
@ -20,6 +20,7 @@ from cscan.config import Xmas_tree, IE_6, IE_8_Win_XP, \
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from cscan.modifiers import no_sni, set_hello_version, set_record_version, \
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no_extensions, truncate_ciphers_to_size, append_ciphers_to_size, \
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extend_with_ext_to_size, add_empty_ext
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from cscan.bisector import Bisect
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def scan_with_config(host, port, conf, hostname, __sentry=None, __cache={}):
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@ -291,6 +292,82 @@ def scan_TLS_intolerancies(host, port, hostname):
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conf.extensions and not
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conf.ssl2))
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#for name in ["Xmas tree", "Huge Cipher List",
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# "Huge Cipher List (trunc c/16388)"]:
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# intolerancies[name] = all(conf_iterator(lambda conf:
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# conf.name == name))
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def test_cb(client_hello):
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ret = scan_with_config(host, port, lambda _:client_hello, hostname)
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return simple_inspector(ret)
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# most size intolerancies lie between 16385 and 16389 so short-circuit to
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# them if possible
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good_conf = next((configs[name] for name, result in results.items()
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if simple_inspector(result)), None)
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if good_conf:
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size_c_16382 = simple_inspector(scan_with_config(host, port,
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append_ciphers_to_size(copy.deepcopy(good_conf), 16382), hostname))
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size_c_16392 = simple_inspector(scan_with_config(host, port,
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append_ciphers_to_size(copy.deepcopy(good_conf), 16392), hostname))
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if size_c_16382 and not size_c_16392:
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good = append_ciphers_to_size(copy.deepcopy(good_conf), 16382)
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bad = append_ciphers_to_size(copy.deepcopy(good_conf), 16392)
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elif not size_c_16382:
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good = good_conf
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bad = append_ciphers_to_size(copy.deepcopy(good_conf), 16382)
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else:
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bad = append_ciphers_to_size(copy.deepcopy(good_conf), 65536)
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size_c_65536 = simple_inspector(scan_with_config(host, port,
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bad, hostname))
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if not size_c_65536:
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good = None
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intolerancies["size c/65536"] = False
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else:
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good = append_ciphers_to_size(copy.deepcopy(good_conf), 16392)
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if good:
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bisect = Bisect(good, bad, hostname, test_cb)
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good_h, bad_h = bisect.run()
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intolerancies["size c/{0}".format(len(bad_h.write()))] = True
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intolerancies["size c/{0}".format(len(good_h.write()))] = False
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# test extension size intolerance, again, most lie between 16385
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# and 16389 so short-circuit if possible
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good_conf = next((configs[name] for name, result in results.items()
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if configs[name].extensions and
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simple_inspector(result)), None)
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if good_conf:
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size_e_16382 = simple_inspector(scan_with_config(host, port,
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extend_with_ext_to_size(copy.deepcopy(good_conf), 16382), hostname))
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size_e_16392 = simple_inspector(scan_with_config(host, port,
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extend_with_ext_to_size(copy.deepcopy(good_conf), 16392), hostname))
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if size_e_16382 and not size_e_16392:
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good = extend_with_ext_to_size(copy.deepcopy(good_conf), 16382)
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bad = extend_with_ext_to_size(copy.deepcopy(good_conf), 16392)
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elif not size_e_16382:
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good = good_conf
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bad = extend_with_ext_to_size(copy.deepcopy(good_conf), 16382)
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else:
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bad = extend_with_ext_to_size(copy.deepcopy(good_conf), 65536)
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size_e_65536 = simple_inspector(scan_with_config(host, port,
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bad, hostname))
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if not size_e_65536:
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good = None
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intolerancies["size e/65536"] = False
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else:
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good = extend_with_ext_to_size(copy.deepcopy(good_conf), 16392)
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if good:
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bisect = Bisect(good, bad, hostname, test_cb)
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good_h, bad_h = bisect.run()
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intolerancies["size e/{0}".format(len(bad_h.write()))] = True
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intolerancies["size e/{0}".format(len(good_h.write()))] = False
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if json_out:
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print(json.dumps(intolerancies))
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else:
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172
cscan/bisector.py
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172
cscan/bisector.py
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@ -0,0 +1,172 @@
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# Copyright (c) 2015 Hubert Kario <hkario@redhat.com>
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# Released under Mozilla Public License Version 2.0
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"""Find an itolerance through bisecting Client Hello"""
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import copy
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from tlslite.extensions import PaddingExtension
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def list_union(first, second):
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"""Return an union between two lists, preserving order"""
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first_i = iter(first)
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second_i = iter(second)
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first_s = set(first)
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second_s = set(second)
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ret = []
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first_el = next(first_i, None)
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second_el = next(second_i, None)
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while first_el is not None and second_el is not None:
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if first_el != second_el:
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if first_el in second_s and second_el in first_s:
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# the second list is longer, so take from it
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ret.append(second_el)
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# no discard as we would have duplicates
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second_el = next(second_i, None)
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continue
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if first_el not in second_s:
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ret.append(first_el)
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first_s.discard(first_el)
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first_el = next(first_i, None)
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if second_el not in first_s:
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ret.append(second_el)
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second_s.discard(second_el)
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second_el = next(second_i, None)
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else:
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ret.append(first_el)
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first_s.discard(first_el)
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second_s.discard(first_el)
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first_el = next(first_i, None)
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second_el = next(second_i, None)
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while first_el:
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if first_el not in second_s:
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ret.append(first_el)
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first_el = next(first_i, None)
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while second_el:
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if second_el not in first_s:
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ret.append(second_el)
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second_el = next(second_i, None)
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return ret
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def bisect_lists(first, second):
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"""Return a list that is in the "middle" between the given ones"""
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# handle None special cases
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if first is None and second is None:
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return None
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if first is not None and second is None:
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first, second = second, first
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if first is None and second is not None:
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if len(second) == 0:
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return None
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elif len(second) == 1:
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return []
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else:
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first = []
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# make the second lists always the longer one
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if len(first) > len(second):
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second, first = first, second
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first_s = set(first)
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second_s = set(second)
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union = list_union(first, second)
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symmetric_diff = first_s.symmetric_difference(second_s)
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# preserve order for the difference
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symmetric_diff = [x for x in union if x in symmetric_diff]
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half_diff = set(symmetric_diff[:len(symmetric_diff)//2])
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intersection = first_s & second_s
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return [x for x in union if x in half_diff or x in intersection]
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def bisect_padding_extension(first, second):
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if first is None and second is None:
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return None
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if first is not None and second is None:
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first, second = second, first
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if first is None and second is not None:
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if len(second.paddingData) == 0:
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return None
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elif len(second.paddingData) == 1:
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return PaddingExtension()
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else:
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first = PaddingExtension()
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return PaddingExtension().create((len(first.paddingData) +
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len(second.paddingData)) // 2)
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def bisect_extensions(first, second):
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# handle padding extension
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if first is None and second is None:
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return None
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if first is not None and second is None:
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first, second = second, first
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if first is None and second is not None:
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if len(second) == 0:
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return None
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if len(second) == 1:
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return []
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first = []
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f_ext = next((x for x in first if isinstance(x, PaddingExtension)), None)
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s_ext = next((x for x in second if isinstance(x, PaddingExtension)), None)
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ext = bisect_padding_extension(f_ext, s_ext)
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if ext is None:
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# remove the extension
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return [x for x in first if not isinstance(x, PaddingExtension)]
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else:
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if f_ext is None:
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return first + [ext]
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# replace extension
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return [ext if isinstance(x, PaddingExtension) else x for x in first]
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def bisect_hellos(first, second):
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"""Return a client hello that is in the "middle" of two other"""
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ret = copy.copy(first)
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ret.client_version = ((first.client_version[0] + second.client_version[0])
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// 2,
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(first.client_version[1] + second.client_version[1])
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// 2)
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ret.cipher_suites = bisect_lists(first.cipher_suites, second.cipher_suites)
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ret.extensions = bisect_lists(first.extensions, second.extensions)
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ret.compression_methods = bisect_lists(first.compression_methods,
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second.compression_methods)
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if first.extensions == ret.extensions \
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or second.extensions == ret.extensions:
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ret.extensions = bisect_extensions(first.extensions,
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second.extensions)
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return ret
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class Bisect(object):
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"""
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Perform a bisection between two Client Hello's to find intolerance
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Tries to find a cause for intolerance by using a bisection-like
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algorithm
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"""
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def __init__(self, good, bad, hostname, callback):
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"""Set the generators for good and bad hello's and callback to test"""
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self.good = good
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self.bad = bad
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if hostname is not None:
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self.hostname = bytearray(hostname, 'utf-8')
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else:
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self.hostname = None
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self.callback = callback
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def run(self):
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good_hello = self.good(self.hostname)
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bad_hello = self.bad(self.hostname)
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middle = bisect_hellos(good_hello, bad_hello)
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while good_hello != middle and \
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middle != bad_hello:
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if self.callback(middle):
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good_hello = middle
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else:
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bad_hello = middle
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middle = bisect_hellos(good_hello, bad_hello)
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return (good_hello, bad_hello)
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258
cscan_tests/test_bisector.py
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258
cscan_tests/test_bisector.py
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# Copyright (c) 2015 Hubert Kario
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# Released under Mozilla Public License Version 2.0
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try:
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import unittest2 as unittest
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except ImportError:
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import unittest
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from tlslite.extensions import SignatureAlgorithmsExtension, SNIExtension, \
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SupportedGroupsExtension, ECPointFormatsExtension, TLSExtension
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from cscan.config import HugeCipherList, VeryCompatible, IE_8_Win_XP
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from cscan.bisector import bisect_lists, list_union, Bisect
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from cscan.modifiers import extend_with_ext_to_size, append_ciphers_to_size
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class TestListUnion(unittest.TestCase):
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def test_identical(self):
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a = [1, 2, 3, 4]
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b = [1, 2, 3, 4]
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c = list_union(a, b)
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self.assertEqual(c, [1, 2, 3, 4])
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def test_extended(self):
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a = [1, 2, 3, 4]
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b = [1, 2, 3, 4, 5, 6, 7, 8]
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c = list_union(a, b)
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self.assertEqual(c, [1, 2, 3, 4, 5, 6, 7, 8])
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def test_extended_reversed(self):
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a = [1, 2, 3, 4, 5, 6, 7, 8]
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b = [1, 2, 3, 4]
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c = list_union(a, b)
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self.assertEqual(c, [1, 2, 3, 4, 5, 6, 7, 8])
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def test_prepended(self):
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a = [5, 6, 7, 8]
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b = [1, 2, 3, 4, 5, 6, 7, 8]
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c = list_union(a, b)
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self.assertEqual(c, [1, 2, 3, 4, 5, 6, 7, 8])
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def test_mixed(self):
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a = [1, 2, 3, 4]
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b = [5, 1, 2, 6, 4]
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c = list_union(a, b)
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self.assertEqual(c, [5, 1, 2, 3, 6, 4])
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def test_mixed_reversed(self):
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a = [5, 1, 2, 6, 4]
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b = [1, 2, 3, 4]
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c = list_union(a, b)
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self.assertEqual(c, [5, 1, 2, 6, 3, 4])
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def test_different_order(self):
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a = [1, 2, 3, 4]
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b = [2, 3, 1, 4]
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c = list_union(a, b)
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self.assertEqual(c, [2, 3, 1, 4])
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def test_different_order2(self):
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a = [1, 2, 3, 4, 5, 6]
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b = [3, 1, 4, 2, 5, 6]
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c = list_union(a, b)
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self.assertEqual(c, [3, 1, 4, 2, 5, 6])
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def test_different_order_superset(self):
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a = [1, 2, 3, 4]
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b = [4, 3, 1, 2, 5, 6]
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c = list_union(a, b)
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self.assertEqual(c, [4, 3, 1, 2, 5, 6])
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def test_completely_disjoint(self):
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a = [1, 2, 3, 4]
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b = [5, 6, 7, 8]
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c = list_union(a, b)
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self.assertEqual(c, [1, 5, 2, 6, 3, 7, 4, 8])
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def test_different_suffix(self):
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a = [1, 2, 3, 4]
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b = [1, 2, 5, 6]
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c = list_union(a, b)
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self.assertEqual(c, [1, 2, 3, 5, 4, 6])
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def test_different_prefix(self):
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a = [1, 2, 3, 4]
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b = [5, 6, 3, 4]
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c = list_union(a, b)
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self.assertEqual(c, [1, 5, 2, 6, 3, 4])
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def test_one_empty(self):
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a = [1, 2, 3, 4]
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b = []
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c = list_union(a, b)
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self.assertEqual(c, [1, 2, 3, 4])
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def test_both_empty(self):
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a = []
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b = []
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c = list_union(a, b)
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self.assertEqual(c, [])
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class TestBisectLists(unittest.TestCase):
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def test_sorted(self):
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a = [1, 5, 7, 9]
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b = [3, 5, 6, 8]
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c = bisect_lists(a, b)
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self.assertEqual(c, [1, 3, 5, 7])
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d = bisect_lists(c, b)
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self.assertEqual(d, [1, 3, 5, 7])
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e = bisect_lists(a, c)
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self.assertEqual(e, [1, 3, 5, 7])
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def test_extended(self):
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a = [1, 2, 3, 4]
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b = [1, 2, 3, 4, 5, 6, 7, 8]
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c = bisect_lists(a, b)
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self.assertEqual(a, [1, 2, 3, 4])
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self.assertEqual(b, [1, 2, 3, 4, 5, 6, 7, 8])
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self.assertEqual(c, [1, 2, 3, 4, 5, 6])
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d = bisect_lists(c, b)
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self.assertEqual(d, [1, 2, 3, 4, 5, 6, 7])
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def test_extended_reversed(self):
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a = [1, 2, 3, 4, 5, 6, 7, 8]
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b = [1, 2, 3, 4]
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c = bisect_lists(a, b)
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self.assertEqual(a, [1, 2, 3, 4, 5, 6, 7, 8])
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self.assertEqual(b, [1, 2, 3, 4])
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self.assertEqual(c, [1, 2, 3, 4, 5, 6])
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def test_prepended(self):
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a = [5, 6, 7, 8]
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b = [1, 2, 3, 4, 5, 6, 7, 8]
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c = bisect_lists(a, b)
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self.assertEqual(c, [1, 2, 5, 6, 7, 8])
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def test_both_different(self):
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a = [1, 2, 3, 4]
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b = [1, 2, 5, 6]
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c = bisect_lists(a, b)
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self.assertEqual(c, [1, 2, 3, 5])
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def test_small_difference(self):
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a = [1, 2, 3, 4]
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b = [1, 2, 3, 5]
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c = bisect_lists(a, b)
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self.assertEqual(c, [1, 2, 3, 4])
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def test_small_difference_with_different_order(self):
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a = [2, 3, 1, 4]
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b = [1, 2, 3, 5]
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c = bisect_lists(a, b)
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self.assertEqual(c, [1, 2, 3, 5])
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def test_one_empty(self):
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a = []
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b = [1, 2, 3, 4]
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c = bisect_lists(a, b)
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self.assertEqual(c, [1, 2])
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def test_both_empty(self):
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a = []
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b = []
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c = bisect_lists(a, b)
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self.assertEqual(c, [])
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|
||||
def test_one_None(self):
|
||||
a = None
|
||||
b = [1, 2, 3, 4]
|
||||
c = bisect_lists(a, b)
|
||||
self.assertEqual(c, [1, 2])
|
||||
|
||||
def test_short_and_None(self):
|
||||
a = None
|
||||
b = [1]
|
||||
c = bisect_lists(a, b)
|
||||
self.assertEqual(c, [])
|
||||
|
||||
def test_empty_and_None(self):
|
||||
a = None
|
||||
b = []
|
||||
c = bisect_lists(a, b)
|
||||
self.assertEqual(c, None)
|
||||
|
||||
class TestBisect(unittest.TestCase):
|
||||
def test___init__(self):
|
||||
b = Bisect(None, None, None, None)
|
||||
self.assertIsNotNone(b)
|
||||
|
||||
def test_run(self):
|
||||
def test_cb(hello):
|
||||
return len(hello.write()) <= 2**14
|
||||
|
||||
bad = HugeCipherList()
|
||||
good = VeryCompatible()
|
||||
self.assertGreater(len(bad(b'').write()), 2**14)
|
||||
self.assertLess(len(good(b'').write()), 2**14)
|
||||
|
||||
bi = Bisect(good, bad, "localhost", test_cb)
|
||||
|
||||
a, b = bi.run()
|
||||
|
||||
self.assertEqual(len(a.write()), 2**14-1)
|
||||
self.assertEqual(len(b.write()), 2**14+1)
|
||||
|
||||
def test_run_with_extensions(self):
|
||||
def test_cb(hello):
|
||||
if not hello.extensions:
|
||||
return True
|
||||
a = next((x for x in hello.extensions
|
||||
if isinstance(x, SignatureAlgorithmsExtension)), None)
|
||||
return a is None
|
||||
good = IE_8_Win_XP()
|
||||
bad = VeryCompatible()
|
||||
|
||||
self.assertTrue(test_cb(good(b'localhost')))
|
||||
self.assertFalse(test_cb(bad(b'localhost')))
|
||||
|
||||
bi = Bisect(good, bad, "localhost", test_cb)
|
||||
|
||||
a, b = bi.run()
|
||||
|
||||
ext = next((x for x in a.extensions
|
||||
if isinstance(x, SignatureAlgorithmsExtension)), None)
|
||||
self.assertIsNone(ext)
|
||||
ext = next((x for x in b.extensions
|
||||
if isinstance(x, SignatureAlgorithmsExtension)), None)
|
||||
self.assertIsNotNone(ext)
|
||||
|
||||
def test_run_with_extension_size(self):
|
||||
def test_cb(hello):
|
||||
return len(hello.write()) <= 2**14
|
||||
|
||||
bad = extend_with_ext_to_size(VeryCompatible(), 2**16)
|
||||
good = VeryCompatible()
|
||||
|
||||
bi = Bisect(good, bad, "localhost", test_cb)
|
||||
|
||||
a, b = bi.run()
|
||||
|
||||
self.assertEqual(len(a.write()), 2**14)
|
||||
self.assertEqual(len(b.write()), 2**14+1)
|
||||
|
||||
def test_run_with_ext_and_ciphers(self):
|
||||
def test_cb(hello):
|
||||
return len(hello.write()) <= 2**14
|
||||
|
||||
bad = extend_with_ext_to_size(VeryCompatible(), 2**15)
|
||||
bad = append_ciphers_to_size(bad, 2**16)
|
||||
good = VeryCompatible()
|
||||
|
||||
bi = Bisect(good, bad, "localhost", test_cb)
|
||||
|
||||
a, b = bi.run()
|
||||
|
||||
self.assertEqual(len(a.write()), 2**14)
|
||||
self.assertEqual(len(b.write()), 2**14+1)
|
Loading…
Reference in New Issue
Block a user