Merge changes I0ab600cd,I1e74c64a am: 798f3afdf6 am: 2f9c4b2c3b am: a9167328fc am: 7563023510 am: 43d8f56cdcandroid-13.0.0_r83android-13.0.0_r82android-13.0.0_r81android-13.0.0_r80android-13.0.0_r79android-13.0.0_r78android-13.0.0_r77android-13.0.0_r76android-13.0.0_r75android-13.0.0_r74android-13.0.0_r73android-13.0.0_r72android-13.0.0_r71android-13.0.0_r70android-13.0.0_r69android-13.0.0_r68android-13.0.0_r67android-13.0.0_r66android-13.0.0_r65android-13.0.0_r64android-13.0.0_r63android-13.0.0_r62android-13.0.0_r61android-13.0.0_r60android-13.0.0_r59android-13.0.0_r58android-13.0.0_r56android-13.0.0_r54android-13.0.0_r53android-13.0.0_r52android-13.0.0_r51android-13.0.0_r50android-13.0.0_r49android-13.0.0_r48android-13.0.0_r47android-13.0.0_r46android-13.0.0_r45android-13.0.0_r44android-13.0.0_r43android-13.0.0_r42android-13.0.0_r41android-13.0.0_r40android-13.0.0_r39android-13.0.0_r38android-13.0.0_r37android-13.0.0_r36android-13.0.0_r35android-13.0.0_r34android-13.0.0_r33android-13.0.0_r32android13-qpr3-s9-releaseandroid13-qpr3-s8-releaseandroid13-qpr3-s7-releaseandroid13-qpr3-s6-releaseandroid13-qpr3-s5-releaseandroid13-qpr3-s4-releaseandroid13-qpr3-s3-releaseandroid13-qpr3-s2-releaseandroid13-qpr3-s14-releaseandroid13-qpr3-s13-releaseandroid13-qpr3-s12-releaseandroid13-qpr3-s11-releaseandroid13-qpr3-s10-releaseandroid13-qpr3-s1-releaseandroid13-qpr3-releaseandroid13-qpr3-c-s8-releaseandroid13-qpr3-c-s7-releaseandroid13-qpr3-c-s6-releaseandroid13-qpr3-c-s5-releaseandroid13-qpr3-c-s4-releaseandroid13-qpr3-c-s3-releaseandroid13-qpr3-c-s2-releaseandroid13-qpr3-c-s12-releaseandroid13-qpr3-c-s11-releaseandroid13-qpr3-c-s10-releaseandroid13-qpr3-c-s1-releaseandroid13-qpr2-s9-releaseandroid13-qpr2-s8-releaseandroid13-qpr2-s7-releaseandroid13-qpr2-s6-releaseandroid13-qpr2-s5-releaseandroid13-qpr2-s3-releaseandroid13-qpr2-s2-releaseandroid13-qpr2-s12-releaseandroid13-qpr2-s11-releaseandroid13-qpr2-s10-releaseandroid13-qpr2-s1-releaseandroid13-qpr2-releaseandroid13-qpr2-b-s1-releaseandroid13-d4-s2-releaseandroid13-d4-s1-releaseandroid13-d4-release

Original change: https://android-review.googlesource.com/c/platform/external/webrtc/+/2062410

Change-Id: I1aa9f459b825711b800cc65782979943a9151ec7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

1 files changed, 29 insertions, 4 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
index 2b8bbe7383..120022c9fb 100644
--- a/third_party/abseil-cpp/absl/random/internal/randen_traits.h
+++ b/third_party/abseil-cpp/absl/random/internal/randen_traits.h
@@ -28,10 +28,29 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace random_internal {
 
-// RANDen = RANDom generator or beetroots in Swiss German.
+// RANDen = RANDom generator or beetroots in Swiss High 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 {
@@ -45,17 +64,23 @@ struct RandenTraits {
   // 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;
 
-  // Type-2 generalized Feistel => one round function for every two blocks.
-  static constexpr size_t kFeistelFunctions = kFeistelBlocks / 2;  // = 8
-
   // 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