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Diffstat (limited to 'lib/Crypto/SelfTest/Protocol/test_SecretSharing.py')
| -rw-r--r-- | lib/Crypto/SelfTest/Protocol/test_SecretSharing.py | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/lib/Crypto/SelfTest/Protocol/test_SecretSharing.py b/lib/Crypto/SelfTest/Protocol/test_SecretSharing.py new file mode 100644 index 0000000..0ea58a5 --- /dev/null +++ b/lib/Crypto/SelfTest/Protocol/test_SecretSharing.py @@ -0,0 +1,267 @@ +# +# SelfTest/Protocol/test_secret_sharing.py: Self-test for secret sharing protocols +# +# =================================================================== +# +# Copyright (c) 2014, Legrandin <helderijs@gmail.com> +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions +# are met: +# +# 1. Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# 2. Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in +# the documentation and/or other materials provided with the +# distribution. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +# COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +# POSSIBILITY OF SUCH DAMAGE. +# =================================================================== + +from unittest import main, TestCase, TestSuite +from binascii import unhexlify, hexlify + +from Crypto.Util.py3compat import * +from Crypto.SelfTest.st_common import list_test_cases + +from Crypto.Protocol.SecretSharing import Shamir, _Element, \ + _mult_gf2, _div_gf2 + +class GF2_Tests(TestCase): + + def test_mult_gf2(self): + # Prove mult by zero + x = _mult_gf2(0,0) + self.assertEqual(x, 0) + + # Prove mult by unity + x = _mult_gf2(34, 1) + self.assertEqual(x, 34) + + z = 3 # (x+1) + y = _mult_gf2(z, z) + self.assertEqual(y, 5) # (x+1)^2 = x^2 + 1 + y = _mult_gf2(y, z) + self.assertEqual(y, 15) # (x+1)^3 = x^3 + x^2 + x + 1 + y = _mult_gf2(y, z) + self.assertEqual(y, 17) # (x+1)^4 = x^4 + 1 + + # Prove linearity works + comps = [1, 4, 128, 2**34] + sum_comps = 1+4+128+2**34 + y = 908 + z = _mult_gf2(sum_comps, y) + w = 0 + for x in comps: + w ^= _mult_gf2(x, y) + self.assertEqual(w, z) + + def test_div_gf2(self): + from Crypto.Util.number import size as deg + + x, y = _div_gf2(567, 7) + self.assertTrue(deg(y) < deg(7)) + + w = _mult_gf2(x, 7) ^ y + self.assertEqual(567, w) + + x, y = _div_gf2(7, 567) + self.assertEqual(x, 0) + self.assertEqual(y, 7) + +class Element_Tests(TestCase): + + def test1(self): + # Test encondings + e = _Element(256) + self.assertEqual(int(e), 256) + self.assertEqual(e.encode(), bchr(0)*14 + b("\x01\x00")) + + e = _Element(bchr(0)*14 + b("\x01\x10")) + self.assertEqual(int(e), 0x110) + self.assertEqual(e.encode(), bchr(0)*14 + b("\x01\x10")) + + # Only 16 byte string are a valid encoding + self.assertRaises(ValueError, _Element, bchr(0)) + + def test2(self): + # Test addition + e = _Element(0x10) + f = _Element(0x0A) + self.assertEqual(int(e+f), 0x1A) + + def test3(self): + # Test multiplication + zero = _Element(0) + one = _Element(1) + two = _Element(2) + + x = _Element(6) * zero + self.assertEqual(int(x), 0) + + x = _Element(6) * one + self.assertEqual(int(x), 6) + + x = _Element(2**127) * two + self.assertEqual(int(x), 1 + 2 + 4 + 128) + + def test4(self): + # Test inversion + one = _Element(1) + + x = one.inverse() + self.assertEqual(int(x), 1) + + x = _Element(82323923) + y = x.inverse() + self.assertEqual(int(x * y), 1) + +class Shamir_Tests(TestCase): + + def test1(self): + # Test splitting + shares = Shamir.split(2, 3, bchr(90)*16) + self.assertEqual(len(shares), 3) + for index in range(3): + self.assertEqual(shares[index][0], index+1) + self.assertEqual(len(shares[index][1]), 16) + + def test2(self): + # Test recombine + from itertools import permutations + + test_vectors = ( + (2, "d9fe73909bae28b3757854c0af7ad405", + "1-594ae8964294174d95c33756d2504170", + "2-d897459d29da574eb40e93ec552ffe6e", + "3-5823de9bf0e068b054b5f07a28056b1b", + "4-db2c1f8bff46d748f795da995bd080cb"), + (2, "bf4f902d9a7efafd1f3ffd9291fd5de9", + "1-557bd3b0748064b533469722d1cc7935", + "2-6b2717164783c66d47cd28f2119f14d0", + "3-8113548ba97d58256bb4424251ae300c", + "4-179e9e5a218483ddaeda57539139cf04"), + (3, "ec96aa5c14c9faa699354cf1da74e904", + "1-64579fbf1908d66f7239bf6e2b4e41e1", + "2-6cd9428df8017b52322561e8c672ae3e", + "3-e418776ef5c0579bd9299277374806dd", + "4-ab3f77a0107398d23b323e581bb43f5d", + "5-23fe42431db2b41bd03ecdc7ea8e97ac"), + (3, "44cf249b68b80fcdc27b47be60c2c145", + "1-d6515a3905cd755119b86e311c801e31", + "2-16693d9ac9f10c254036ced5f8917fa3", + "3-84f74338a48476b99bf5e75a84d3a0d1", + "4-3fe8878dc4a5d35811cf3cbcd33dbe52", + "5-ad76f92fa9d0a9c4ca0c1533af7f6132"), + (5, "5398717c982db935d968eebe53a47f5a", + "1-be7be2dd4c068e7ef576aaa1b1c11b01", + "2-f821f5848441cb98b3eb467e2733ee21", + "3-25ee52f53e203f6e29a0297b5ab486b5", + "4-fc9fb58ef74dab947fbf9acd9d5d83cd", + "5-b1949cce46d81552e65f248d3f74cc5c", + "6-d64797f59977c4d4a7956ad916da7699", + "7-ab608a6546a8b9af8820ff832b1135c7"), + (5, "4a78db90fbf35da5545d2fb728e87596", + "1-08daf9a25d8aa184cfbf02b30a0ed6a0", + "2-dda28261e36f0b14168c2cf153fb734e", + "3-e9fdec5505d674a57f9836c417c1ecaa", + "4-4dce5636ae06dee42d2c82e65f06c735", + "5-3963dc118afc2ba798fa1d452b28ef00", + "6-6dfe6ff5b09e94d2f84c382b12f42424", + "7-6faea9d4d4a4e201bf6c90b9000630c3"), + (10, "eccbf6d66d680b49b073c4f1ddf804aa", + "01-7d8ac32fe4ae209ead1f3220fda34466", + "02-f9144e76988aad647d2e61353a6e96d5", + "03-b14c3b80179203363922d60760271c98", + "04-770bb2a8c28f6cee89e00f4d5cc7f861", + "05-6e3d7073ea368334ef67467871c66799", + "06-248792bc74a98ce024477c13c8fb5f8d", + "07-fcea4640d2db820c0604851e293d2487", + "08-2776c36fb714bb1f8525a0be36fc7dba", + "09-6ee7ac8be773e473a4bf75ee5f065762", + "10-33657fc073354cf91d4a68c735aacfc8", + "11-7645c65094a5868bf225c516fdee2d0c", + "12-840485aacb8226631ecd9c70e3018086"), + (10, "377e63bdbb5f7d4dc58a483d035212bb", + "01-32c53260103be431c843b1a633afe3bd", + "02-0107eb16cb8695084d452d2cc50bc7d6", + "03-df1e5c66cd755287fb0446faccd72a06", + "04-361bbcd5d40797f49dfa1898652da197", + "05-160d3ad1512f7dec7fd9344aed318591", + "06-659af6d95df4f25beca4fb9bfee3b7e8", + "07-37f3b208977bad50b3724566b72bfa9d", + "08-6c1de2dfc69c2986142c26a8248eb316", + "09-5e19220837a396bd4bc8cd685ff314c3", + "10-86e7b864fb0f3d628e46d50c1ba92f1c", + "11-065d0082c80b1aea18f4abe0c49df72e", + "12-84a09430c1d20ea9f388f3123c3733a3"), + ) + + def get_share(p): + pos = p.find('-') + return int(p[:pos]), unhexlify(p[pos + 1:]) + + for tv in test_vectors: + k = tv[0] + secret = unhexlify(tv[1]) + max_perms = 10 + for perm, shares_idx in enumerate(permutations(range(2, len(tv)), k)): + if perm > max_perms: + break + shares = [ get_share(tv[x]) for x in shares_idx ] + result = Shamir.combine(shares, True) + self.assertEqual(secret, result) + + def test3(self): + # Loopback split/recombine + secret = unhexlify(b("000102030405060708090a0b0c0d0e0f")) + + shares = Shamir.split(2, 3, secret) + + secret2 = Shamir.combine(shares[:2]) + self.assertEqual(secret, secret2) + + secret3 = Shamir.combine([ shares[0], shares[2] ]) + self.assertEqual(secret, secret3) + + def test4(self): + # Loopback split/recombine (SSSS) + secret = unhexlify(b("000102030405060708090a0b0c0d0e0f")) + + shares = Shamir.split(2, 3, secret, ssss=True) + + secret2 = Shamir.combine(shares[:2], ssss=True) + self.assertEqual(secret, secret2) + + def test5(self): + # Detect duplicate shares + secret = unhexlify(b("000102030405060708090a0b0c0d0e0f")) + + shares = Shamir.split(2, 3, secret) + self.assertRaises(ValueError, Shamir.combine, (shares[0], shares[0])) + + +def get_tests(config={}): + tests = [] + tests += list_test_cases(GF2_Tests) + tests += list_test_cases(Element_Tests) + tests += list_test_cases(Shamir_Tests) + return tests + +if __name__ == '__main__': + suite = lambda: TestSuite(get_tests()) + main(defaultTest='suite') + |