diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/random/internal/randen.cc')
-rw-r--r-- | third_party/abseil_cpp/absl/random/internal/randen.cc | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/third_party/abseil_cpp/absl/random/internal/randen.cc b/third_party/abseil_cpp/absl/random/internal/randen.cc deleted file mode 100644 index 78a1e00c0832..000000000000 --- a/third_party/abseil_cpp/absl/random/internal/randen.cc +++ /dev/null @@ -1,91 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -#include "absl/random/internal/randen.h" - -#include "absl/base/internal/raw_logging.h" -#include "absl/random/internal/randen_detect.h" - -// RANDen = RANDom generator or beetroots in Swiss German. -// 'Strong' (well-distributed, unpredictable, backtracking-resistant) random -// generator, faster in some benchmarks than std::mt19937_64 and pcg64_c32. -// -// High-level summary: -// 1) Reverie (see "A Robust and Sponge-Like PRNG with Improved Efficiency") is -// a sponge-like random generator that requires a cryptographic permutation. -// It improves upon "Provably Robust Sponge-Based PRNGs and KDFs" by -// achieving backtracking resistance with only one Permute() per buffer. -// -// 2) "Simpira v2: A Family of Efficient Permutations Using the AES Round -// Function" constructs up to 1024-bit permutations using an improved -// Generalized Feistel network with 2-round AES-128 functions. This Feistel -// block shuffle achieves diffusion faster and is less vulnerable to -// sliced-biclique attacks than the Type-2 cyclic shuffle. -// -// 3) "Improving the Generalized Feistel" and "New criterion for diffusion -// property" extends the same kind of improved Feistel block shuffle to 16 -// branches, which enables a 2048-bit permutation. -// -// We combine these three ideas and also change Simpira's subround keys from -// structured/low-entropy counters to digits of Pi. - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace random_internal { -namespace { - -struct RandenState { - const void* keys; - bool has_crypto; -}; - -RandenState GetRandenState() { - static const RandenState state = []() { - RandenState tmp; -#if ABSL_RANDOM_INTERNAL_AES_DISPATCH - // HW AES Dispatch. - if (HasRandenHwAesImplementation() && CPUSupportsRandenHwAes()) { - tmp.has_crypto = true; - tmp.keys = RandenHwAes::GetKeys(); - } else { - tmp.has_crypto = false; - tmp.keys = RandenSlow::GetKeys(); - } -#elif ABSL_HAVE_ACCELERATED_AES - // HW AES is enabled. - tmp.has_crypto = true; - tmp.keys = RandenHwAes::GetKeys(); -#else - // HW AES is disabled. - tmp.has_crypto = false; - tmp.keys = RandenSlow::GetKeys(); -#endif - return tmp; - }(); - return state; -} - -} // namespace - -Randen::Randen() { - auto tmp = GetRandenState(); - keys_ = tmp.keys; -#if ABSL_RANDOM_INTERNAL_AES_DISPATCH - has_crypto_ = tmp.has_crypto; -#endif -} - -} // namespace random_internal -ABSL_NAMESPACE_END -} // namespace absl |