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Diffstat (limited to 'third_party/abseil_cpp/absl/random/internal/randen_traits.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/random/internal/randen_traits.h | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/third_party/abseil_cpp/absl/random/internal/randen_traits.h b/third_party/abseil_cpp/absl/random/internal/randen_traits.h deleted file mode 100644 index 53caa936140a..000000000000 --- a/third_party/abseil_cpp/absl/random/internal/randen_traits.h +++ /dev/null @@ -1,88 +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. - -#ifndef ABSL_RANDOM_INTERNAL_RANDEN_TRAITS_H_ -#define ABSL_RANDOM_INTERNAL_RANDEN_TRAITS_H_ - -// HERMETIC NOTE: The randen_hwaes target must not introduce duplicate -// symbols from arbitrary system and other headers, since it may be built -// with different flags from other targets, using different levels of -// optimization, potentially introducing ODR violations. - -#include <cstddef> - -#include "absl/base/config.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace random_internal { - -// 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. -// -// Combine these three ideas and also change Simpira's subround keys from -// structured/low-entropy counters to digits of Pi (or other random source). - -// RandenTraits contains the basic algorithm traits, such as the size of the -// state, seed, sponge, etc. -struct RandenTraits { - // Size of the entire sponge / state for the randen PRNG. - static constexpr size_t kStateBytes = 256; // 2048-bit - - // Size of the 'inner' (inaccessible) part of the sponge. Larger values would - // require more frequent calls to RandenGenerate. - static constexpr size_t kCapacityBytes = 16; // 128-bit - - // Size of the default seed consumed by the sponge. - static constexpr size_t kSeedBytes = kStateBytes - kCapacityBytes; - - // Assuming 128-bit blocks, the number of blocks in the state. - // Largest size for which security proofs are known. - static constexpr size_t kFeistelBlocks = 16; - - // Ensures SPRP security and two full subblock diffusions. - // Must be > 4 * log2(kFeistelBlocks). - static constexpr size_t kFeistelRounds = 16 + 1; - - // Size of the key. A 128-bit key block is used for every-other - // feistel block (Type-2 generalized Feistel network) in each round. - static constexpr size_t kKeyBytes = 16 * kFeistelRounds * kFeistelBlocks / 2; -}; - -// Randen key arrays. In randen_round_keys.cc -extern const unsigned char kRandenRoundKeys[RandenTraits::kKeyBytes]; -extern const unsigned char kRandenRoundKeysBE[RandenTraits::kKeyBytes]; - -} // namespace random_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_RANDOM_INTERNAL_RANDEN_TRAITS_H_ |