# # SelfTest/Protocol/test_secret_sharing.py: Self-test for secret sharing protocols # # =================================================================== # # Copyright (c) 2014, Legrandin # 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')