src/test/random_tests.cpp

   1 // Copyright (c) 2017 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #include "random.h"
   6
   7 #include "test/test_bitcoin.h"
   8
   9 #include <boost/test/unit_test.hpp>
  10
  11 BOOST_FIXTURE_TEST_SUITE(random_tests, BasicTestingSetup)
  12
  13 BOOST_AUTO_TEST_CASE(osrandom_tests)
  14 {
  15     BOOST_CHECK(Random_SanityCheck());
  16 }
  17
  18 BOOST_AUTO_TEST_CASE(fastrandom_tests)
  19 {
  20     // Check that deterministic FastRandomContexts are deterministic
  21     FastRandomContext ctx1(true);
  22     FastRandomContext ctx2(true);
  23
  24     BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32());
  25     BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32());
  26     BOOST_CHECK_EQUAL(ctx1.rand64(), ctx2.rand64());
  27     BOOST_CHECK_EQUAL(ctx1.randbits(3), ctx2.randbits(3));
  28     BOOST_CHECK(ctx1.randbytes(17) == ctx2.randbytes(17));
  29     BOOST_CHECK(ctx1.rand256() == ctx2.rand256());
  30     BOOST_CHECK_EQUAL(ctx1.randbits(7), ctx2.randbits(7));
  31     BOOST_CHECK(ctx1.randbytes(128) == ctx2.randbytes(128));
  32     BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32());
  33     BOOST_CHECK_EQUAL(ctx1.randbits(3), ctx2.randbits(3));
  34     BOOST_CHECK(ctx1.rand256() == ctx2.rand256());
  35     BOOST_CHECK(ctx1.randbytes(50) == ctx2.randbytes(50));
  36
  37     // Check that a nondeterministic ones are not
  38     FastRandomContext ctx3;
  39     FastRandomContext ctx4;
  40     BOOST_CHECK(ctx3.rand64() != ctx4.rand64()); // extremely unlikely to be equal
  41     BOOST_CHECK(ctx3.rand256() != ctx4.rand256());
  42     BOOST_CHECK(ctx3.randbytes(7) != ctx4.randbytes(7));
  43 }
  44
  45 BOOST_AUTO_TEST_CASE(fastrandom_randbits)
  46 {
  47     FastRandomContext ctx1;
  48     FastRandomContext ctx2;
  49     for (int bits = 0; bits < 63; ++bits) {
  50         for (int j = 0; j < 1000; ++j) {
  51             uint64_t rangebits = ctx1.randbits(bits);
  52             BOOST_CHECK_EQUAL(rangebits >> bits, 0);
  53             uint64_t range = ((uint64_t)1) << bits | rangebits;
  54             uint64_t rand = ctx2.randrange(range);
  55             BOOST_CHECK(rand < range);
  56         }
  57     }
  58 }
  59
  60 BOOST_AUTO_TEST_SUITE_END()