From a8cad7ed4c15b2d0e6d2416d3b93e860e03cfc62 Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Wed, 27 Mar 2024 14:31:48 -0700 Subject: [PATCH] Add FastRandomContext::rand256() and ::randbytes() FastRandomContext now provides all functionality that the real Rand* functions provide. Cherry-picked from: 37e864eb9fee4b592bd61c5ec3555b00a2de2cf7 --- src/random.cpp | 20 ++++++++++++++++++++ src/random.h | 6 ++++++ src/test/cuckoocache_tests.cpp | 24 ++++++++++++------------ src/test/random_tests.cpp | 7 +++++++ 4 files changed, 45 insertions(+), 12 deletions(-) diff --git a/src/random.cpp b/src/random.cpp index c1e313cbd..0e8f83dd8 100644 --- a/src/random.cpp +++ b/src/random.cpp @@ -247,6 +247,26 @@ void FastRandomContext::RandomSeed() requires_seed = false; } +uint256 FastRandomContext::rand256() +{ + if (bytebuf_size < 32) { + FillByteBuffer(); + } + uint256 ret; + memcpy(ret.begin(), bytebuf + 64 - bytebuf_size, 32); + bytebuf_size -= 32; + return ret; +} + +std::vector FastRandomContext::randbytes(size_t len) +{ + std::vector ret(len); + if (len > 0) { + rng.Output(&ret[0], len); + } + return ret; +} + FastRandomContext::FastRandomContext(const uint256& seed) : requires_seed(false), bytebuf_size(0), bitbuf_size(0) { rng.SetKey(seed.begin(), 32); diff --git a/src/random.h b/src/random.h index 9551e1c46..f8e2e0dc5 100644 --- a/src/random.h +++ b/src/random.h @@ -103,9 +103,15 @@ public: } } + /** Generate random bytes. */ + std::vector randbytes(size_t len); + /** Generate a random 32-bit integer. */ uint32_t rand32() { return randbits(32); } + /** generate a random uint256. */ + uint256 rand256(); + /** Generate a random boolean. */ bool randbool() { return randbits(1); } }; diff --git a/src/test/cuckoocache_tests.cpp b/src/test/cuckoocache_tests.cpp index 6004b25aa..916b23cee 100644 --- a/src/test/cuckoocache_tests.cpp +++ b/src/test/cuckoocache_tests.cpp @@ -24,18 +24,18 @@ * using BOOST_CHECK_CLOSE to fail. * */ -FastRandomContext insecure_rand(true); +FastRandomContext local_rand_ctx(true); BOOST_AUTO_TEST_SUITE(cuckoocache_tests); -/** insecure_GetRandHash fills in a uint256 from insecure_rand +/** insecure_GetRandHash fills in a uint256 from local_rand_ctx */ void insecure_GetRandHash(uint256& t) { uint32_t* ptr = (uint32_t*)t.begin(); for (uint8_t j = 0; j < 8; ++j) - *(ptr++) = insecure_rand.rand32(); + *(ptr++) = local_rand_ctx.rand32(); } /** Definition copied from /src/script/sigcache.cpp @@ -60,7 +60,7 @@ public: */ BOOST_AUTO_TEST_CASE(test_cuckoocache_no_fakes) { - insecure_rand = FastRandomContext(true); + local_rand_ctx = FastRandomContext(true); CuckooCache::cache cc{}; cc.setup_bytes(32 << 20); uint256 v; @@ -80,7 +80,7 @@ BOOST_AUTO_TEST_CASE(test_cuckoocache_no_fakes) template double test_cache(size_t megabytes, double load) { - insecure_rand = FastRandomContext(true); + local_rand_ctx = FastRandomContext(true); std::vector hashes; Cache set{}; size_t bytes = megabytes * (1 << 20); @@ -90,7 +90,7 @@ double test_cache(size_t megabytes, double load) for (uint32_t i = 0; i < n_insert; ++i) { uint32_t* ptr = (uint32_t*)hashes[i].begin(); for (uint8_t j = 0; j < 8; ++j) - *(ptr++) = insecure_rand.rand32(); + *(ptr++) = local_rand_ctx.rand32(); } /** We make a copy of the hashes because future optimizations of the * cuckoocache may overwrite the inserted element, so the test is @@ -151,7 +151,7 @@ template void test_cache_erase(size_t megabytes) { double load = 1; - insecure_rand = FastRandomContext(true); + local_rand_ctx = FastRandomContext(true); std::vector hashes; Cache set{}; size_t bytes = megabytes * (1 << 20); @@ -161,7 +161,7 @@ void test_cache_erase(size_t megabytes) for (uint32_t i = 0; i < n_insert; ++i) { uint32_t* ptr = (uint32_t*)hashes[i].begin(); for (uint8_t j = 0; j < 8; ++j) - *(ptr++) = insecure_rand.rand32(); + *(ptr++) = local_rand_ctx.rand32(); } /** We make a copy of the hashes because future optimizations of the * cuckoocache may overwrite the inserted element, so the test is @@ -214,7 +214,7 @@ template void test_cache_erase_parallel(size_t megabytes) { double load = 1; - insecure_rand = FastRandomContext(true); + local_rand_ctx = FastRandomContext(true); std::vector hashes; Cache set{}; size_t bytes = megabytes * (1 << 20); @@ -224,7 +224,7 @@ void test_cache_erase_parallel(size_t megabytes) for (uint32_t i = 0; i < n_insert; ++i) { uint32_t* ptr = (uint32_t*)hashes[i].begin(); for (uint8_t j = 0; j < 8; ++j) - *(ptr++) = insecure_rand.rand32(); + *(ptr++) = local_rand_ctx.rand32(); } /** We make a copy of the hashes because future optimizations of the * cuckoocache may overwrite the inserted element, so the test is @@ -316,7 +316,7 @@ void test_cache_generations() // iterations with non-deterministic values, so it isn't "overfit" to the // specific entropy in FastRandomContext(true) and implementation of the // cache. - insecure_rand = FastRandomContext(true); + local_rand_ctx = FastRandomContext(true); // block_activity models a chunk of network activity. n_insert elements are // adde to the cache. The first and last n/4 are stored for removal later @@ -333,7 +333,7 @@ void test_cache_generations() for (uint32_t i = 0; i < n_insert; ++i) { uint32_t* ptr = (uint32_t*)inserts[i].begin(); for (uint8_t j = 0; j < 8; ++j) - *(ptr++) = insecure_rand.rand32(); + *(ptr++) = local_rand_ctx.rand32(); } for (uint32_t i = 0; i < n_insert / 4; ++i) reads.push_back(inserts[i]); diff --git a/src/test/random_tests.cpp b/src/test/random_tests.cpp index 859673422..132e19005 100644 --- a/src/test/random_tests.cpp +++ b/src/test/random_tests.cpp @@ -25,14 +25,21 @@ BOOST_AUTO_TEST_CASE(fastrandom_tests) BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32()); BOOST_CHECK_EQUAL(ctx1.rand64(), ctx2.rand64()); BOOST_CHECK_EQUAL(ctx1.randbits(3), ctx2.randbits(3)); + BOOST_CHECK(ctx1.randbytes(17) == ctx2.randbytes(17)); + BOOST_CHECK(ctx1.rand256() == ctx2.rand256()); BOOST_CHECK_EQUAL(ctx1.randbits(7), ctx2.randbits(7)); + BOOST_CHECK(ctx1.randbytes(128) == ctx2.randbytes(128)); BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32()); BOOST_CHECK_EQUAL(ctx1.randbits(3), ctx2.randbits(3)); + BOOST_CHECK(ctx1.rand256() == ctx2.rand256()); + BOOST_CHECK(ctx1.randbytes(50) == ctx2.randbytes(50)); // Check that a nondeterministic ones are not FastRandomContext ctx3; FastRandomContext ctx4; BOOST_CHECK(ctx3.rand64() != ctx4.rand64()); // extremely unlikely to be equal + BOOST_CHECK(ctx3.rand256() != ctx4.rand256()); + BOOST_CHECK(ctx3.randbytes(7) != ctx4.randbytes(7)); } BOOST_AUTO_TEST_CASE(fastrandom_randbits)