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Editing: test_modexp.py
# # SelfTest/Math/test_modexp.py: Self-test for module exponentiation # # =================================================================== # # Copyright (c) 2017, Helder Eijs <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. # =================================================================== """Self-test for the custom module exponentiation""" import unittest from Crypto.SelfTest.st_common import list_test_cases from Crypto.Util.number import long_to_bytes, bytes_to_long from Crypto.Util.py3compat import * from Crypto.Util._raw_api import (load_pycryptodome_raw_lib, create_string_buffer, get_raw_buffer, c_size_t, c_ulonglong) from Crypto.Hash import SHAKE128 from Crypto.Math.Numbers import Integer from Crypto.Math._IntegerCustom import _raw_montgomery from Crypto.Random.random import StrongRandom def create_rng(tag): rng = StrongRandom(SHAKE128.new(data=tag)) return rng class ExceptionModulus(ValueError): pass def monty_pow(base, exp, modulus): max_len = len(long_to_bytes(max(base, exp, modulus))) base_b, exp_b, modulus_b = [ long_to_bytes(x, max_len) for x in (base, exp, modulus) ] out = create_string_buffer(max_len) error = _raw_montgomery.monty_pow( out, base_b, exp_b, modulus_b, c_size_t(max_len), c_ulonglong(32) ) if error == 17: raise ExceptionModulus() if error: raise ValueError("monty_pow failed with error: %d" % error) result = bytes_to_long(get_raw_buffer(out)) return result exponent1 = 0x2ce0af628901460a419a08ef950d498b9fd6f271a1a52ac293b86fe5c60efe8e8ba93fa1ebe1eb3d614d2e7b328cb60a2591440e163441a190ecf101ceec245f600fffdcf3f5b3a17a7baeacb96a424db1d7ec985e8ec998bb479fecfffed6a75f9a90fc97062fd973303bce855ad7b8d8272a94025e8532be9aabd54a183f303538d2a7e621b4131d59e823a4625f39bd7d518d7784f7c3a8f19061da74974ff42fa1c063dec2db97d461e291a7d6e721708a5229de166c1246363372854e27f3f08ae274bc16bfd205b028a4d81386494433d516dfbb35f495acba5e4e1d1843cb3c3129b6642a85fc7244ce5845fac071c7f622e4ee12ac43fabeeaa0cd01 modulus1 = 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 class TestModExp(unittest.TestCase): def test_small(self): self.assertEqual(1, monty_pow(11,12,19)) def test_large_1(self): base = 0xfffffffffffffffffffffffffffffffffffffffffffffffffff expected = pow(base, exponent1, modulus1) result = monty_pow(base, exponent1, modulus1) self.assertEqual(result, expected) def test_zero_exp(self): base = 0xfffffffffffffffffffffffffffffffffffffffffffffffffff result = monty_pow(base, 0, modulus1) self.assertEqual(result, 1) def test_zero_base(self): result = monty_pow(0, exponent1, modulus1) self.assertEqual(result, 0) def test_zero_modulus(self): base = 0xfffffffffffffffffffffffffffffffffffffffffffffffff self.assertRaises(ExceptionModulus, monty_pow, base, exponent1, 0) self.assertRaises(ExceptionModulus, monty_pow, 0, 0, 0) def test_larger_exponent(self): base = modulus1 - 0xFFFFFFF expected = pow(base, modulus1<<64, modulus1) result = monty_pow(base, modulus1<<64, modulus1) self.assertEqual(result, expected) def test_even_modulus(self): base = modulus1 >> 4 self.assertRaises(ExceptionModulus, monty_pow, base, exponent1, modulus1-1) def test_several_lengths(self): prng = SHAKE128.new().update(b('Test')) for length in range(1, 100): modulus2 = Integer.from_bytes(prng.read(length)) | 1 base = Integer.from_bytes(prng.read(length)) % modulus2 exponent2 = Integer.from_bytes(prng.read(length)) expected = pow(base, exponent2, modulus2) result = monty_pow(base, exponent2, modulus2) self.assertEqual(result, expected) def test_variable_exponent(self): prng = create_rng(b('Test variable exponent')) for i in range(20): for j in range(7): modulus = prng.getrandbits(8*30) | 1 base = prng.getrandbits(8*30) % modulus exponent = prng.getrandbits(i*8+j) expected = pow(base, exponent, modulus) result = monty_pow(base, exponent, modulus) self.assertEqual(result, expected) exponent ^= (1 << (i*8+j)) - 1 expected = pow(base, exponent, modulus) result = monty_pow(base, exponent, modulus) self.assertEqual(result, expected) def test_stress_63(self): prng = create_rng(b('Test 63')) length = 63 for _ in range(2000): modulus = prng.getrandbits(8*length) | 1 base = prng.getrandbits(8*length) % modulus exponent = prng.getrandbits(8*length) expected = pow(base, exponent, modulus) result = monty_pow(base, exponent, modulus) self.assertEqual(result, expected) def test_stress_64(self): prng = create_rng(b('Test 64')) length = 64 for _ in range(2000): modulus = prng.getrandbits(8*length) | 1 base = prng.getrandbits(8*length) % modulus exponent = prng.getrandbits(8*length) expected = pow(base, exponent, modulus) result = monty_pow(base, exponent, modulus) self.assertEqual(result, expected) def test_stress_65(self): prng = create_rng(b('Test 65')) length = 65 for _ in range(2000): modulus = prng.getrandbits(8*length) | 1 base = prng.getrandbits(8*length) % modulus exponent = prng.getrandbits(8*length) expected = pow(base, exponent, modulus) result = monty_pow(base, exponent, modulus) self.assertEqual(result, expected) def get_tests(config={}): tests = [] tests += list_test_cases(TestModExp) return tests if __name__ == '__main__': suite = lambda: unittest.TestSuite(get_tests()) unittest.main(defaultTest='suite')
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