ringct: a few minor optimizations from review

This commit is contained in:
moneromooo-monero 2021-02-11 22:28:08 +00:00
parent a0d80b1f95
commit 75bd004f4e
No known key found for this signature in database
GPG Key ID: 686F07454D6CEFC3
1 changed files with 15 additions and 18 deletions

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@ -68,17 +68,16 @@ namespace rct
static constexpr size_t maxM = BULLETPROOF_PLUS_MAX_OUTPUTS; // maximum number of outputs to aggregate into a single proof
// Cached public generators
static rct::key Hi[maxN*maxM], Gi[maxN*maxM];
static ge_p3 Hi_p3[maxN*maxM], Gi_p3[maxN*maxM];
static std::shared_ptr<straus_cached_data> straus_HiGi_cache;
static std::shared_ptr<pippenger_cached_data> pippenger_HiGi_cache;
// Useful scalar constants
static const rct::key ZERO = { {0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 } }; // 0
static const rct::key ONE = { {0x01, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 } }; // 1
static const rct::key TWO = { {0x02, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 } }; // 2
static const rct::key MINUS_ONE = { { 0xec, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10 } }; // -1
static const rct::key MINUS_INV_EIGHT = { { 0x74, 0xa4, 0x19, 0x7a, 0xf0, 0x7d, 0x0b, 0xf7, 0x05, 0xc2, 0xda, 0x25, 0x2b, 0x5c, 0x0b, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a } }; // -(8**(-1))
static const constexpr rct::key ZERO = { {0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 } }; // 0
static const constexpr rct::key ONE = { {0x01, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 } }; // 1
static const constexpr rct::key TWO = { {0x02, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 } }; // 2
static const constexpr rct::key MINUS_ONE = { { 0xec, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10 } }; // -1
static const constexpr rct::key MINUS_INV_EIGHT = { { 0x74, 0xa4, 0x19, 0x7a, 0xf0, 0x7d, 0x0b, 0xf7, 0x05, 0xc2, 0xda, 0x25, 0x2b, 0x5c, 0x0b, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a } }; // -(8**(-1))
static rct::key TWO_SIXTY_FOUR_MINUS_ONE; // 2**64 - 1
// Initial transcript hash
@ -107,16 +106,15 @@ namespace rct
}
// Use hashed values to produce indexed public generators
static rct::key get_exponent(const rct::key &base, size_t idx)
static ge_p3 get_exponent(const rct::key &base, size_t idx)
{
static const std::string domain_separator(config::HASH_KEY_BULLETPROOF_PLUS_EXPONENT);
std::string hashed = std::string((const char*)base.bytes, sizeof(base)) + domain_separator + tools::get_varint_data(idx);
std::string hashed = std::string((const char*)base.bytes, sizeof(base)) + config::HASH_KEY_BULLETPROOF_PLUS_EXPONENT + tools::get_varint_data(idx);
rct::key generator;
ge_p3 generator_p3;
rct::hash_to_p3(generator_p3, rct::hash2rct(crypto::cn_fast_hash(hashed.data(), hashed.size())));
ge_p3_tobytes(generator.bytes, &generator_p3);
CHECK_AND_ASSERT_THROW_MES(!(generator == rct::identity()), "Exponent is point at infinity");
return generator;
return generator_p3;
}
// Construct public generators
@ -133,10 +131,8 @@ namespace rct
data.reserve(maxN*maxM*2);
for (size_t i = 0; i < maxN*maxM; ++i)
{
Hi[i] = get_exponent(rct::H, i * 2);
CHECK_AND_ASSERT_THROW_MES(ge_frombytes_vartime(&Hi_p3[i], Hi[i].bytes) == 0, "ge_frombytes_vartime failed");
Gi[i] = get_exponent(rct::H, i * 2 + 1);
CHECK_AND_ASSERT_THROW_MES(ge_frombytes_vartime(&Gi_p3[i], Gi[i].bytes) == 0, "ge_frombytes_vartime failed");
Hi_p3[i] = get_exponent(rct::H, i * 2);
Gi_p3[i] = get_exponent(rct::H, i * 2 + 1);
data.push_back({rct::zero(), Gi_p3[i]});
data.push_back({rct::zero(), Hi_p3[i]});
@ -154,7 +150,7 @@ namespace rct
sc_sub(TWO_SIXTY_FOUR_MINUS_ONE.bytes, TWO_SIXTY_FOUR_MINUS_ONE.bytes, ONE.bytes);
// Generate the initial Fiat-Shamir transcript hash, which is constant across all proofs
static const std::string domain_separator(config::HASH_KEY_BULLETPROOF_PLUS_TRANSCRIPT);
const std::string domain_separator(config::HASH_KEY_BULLETPROOF_PLUS_TRANSCRIPT);
ge_p3 initial_transcript_p3;
rct::hash_to_p3(initial_transcript_p3, rct::hash2rct(crypto::cn_fast_hash(domain_separator.data(), domain_separator.size())));
ge_p3_tobytes(initial_transcript.bytes, &initial_transcript_p3);
@ -846,7 +842,8 @@ try_again:
max_length = std::max(max_length, proof.L.size());
nV += proof.V.size();
bp_plus_proof_data_t pd;
proof_data.push_back({});
bp_plus_proof_data_t &pd = proof_data.back();
// Reconstruct the challenges
rct::key transcript = copy(initial_transcript);
@ -883,7 +880,6 @@ try_again:
to_invert.push_back(pd.challenges[j]);
to_invert.push_back(pd.y);
inv_offset += rounds + 1;
proof_data.push_back(pd);
}
CHECK_AND_ASSERT_MES(max_length < 32, false, "At least one proof is too large");
size_t maxMN = 1u << max_length;
@ -896,7 +892,8 @@ try_again:
multiexp_data.reserve(nV + (2 * (max_logM + logN) + 3) * proofs.size() + 2 * maxMN);
multiexp_data.resize(2 * maxMN);
const std::vector<rct::key> inverses = invert(to_invert);
const std::vector<rct::key> inverses = invert(std::move(to_invert));
to_invert.clear();
// Weights and aggregates
//