Merge pull request #4761

6e1282b6 wallet2: fix off by one in output picking (moneromooo-monero)
This commit is contained in:
Riccardo Spagni 2018-11-14 21:34:50 +02:00
commit 33ad6fb4c1
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GPG key ID: 55432DF31CCD4FCD

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@ -6841,21 +6841,23 @@ void wallet2::get_outs(std::vector<std::vector<tools::wallet2::get_outs_entry>>
//static const double shape = m_testnet ? 17.02 : 17.28;
static const double scale = 1/1.61;
std::gamma_distribution<double> gamma(shape, scale);
THROW_WALLET_EXCEPTION_IF(rct_offsets.size() <= CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE, error::wallet_internal_error, "Bad offset calculation");
uint64_t last_usable_block = rct_offsets.size() - 1;
auto pick_gamma = [&]()
{
double x = gamma(engine);
x = exp(x);
uint64_t block_offset = x / DIFFICULTY_TARGET_V2; // this assumes constant target over the whole rct range
if (block_offset >= rct_offsets.size() - 1)
if (block_offset > last_usable_block - CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE)
return std::numeric_limits<uint64_t>::max(); // bad pick
block_offset = rct_offsets.size() - 2 - block_offset;
THROW_WALLET_EXCEPTION_IF(block_offset >= rct_offsets.size() - 1, error::wallet_internal_error, "Bad offset calculation");
THROW_WALLET_EXCEPTION_IF(rct_offsets[block_offset + 1] < rct_offsets[block_offset],
block_offset = last_usable_block - block_offset;
THROW_WALLET_EXCEPTION_IF(block_offset > last_usable_block, error::wallet_internal_error, "Bad offset calculation");
THROW_WALLET_EXCEPTION_IF(block_offset > 0 && rct_offsets[block_offset] < rct_offsets[block_offset - 1],
error::get_output_distribution, "Decreasing offsets in rct distribution: " +
std::to_string(block_offset) + ": " + std::to_string(rct_offsets[block_offset]) + ", " +
std::to_string(block_offset + 1) + ": " + std::to_string(rct_offsets[block_offset + 1]));
std::to_string(block_offset - 1) + ": " + std::to_string(rct_offsets[block_offset - 1]) + ", " +
std::to_string(block_offset) + ": " + std::to_string(rct_offsets[block_offset]));
uint64_t first_block_offset = block_offset, last_block_offset = block_offset;
for (size_t half_window = 0; half_window < GAMMA_PICK_HALF_WINDOW; ++half_window)
for (size_t half_window = 0; half_window <= GAMMA_PICK_HALF_WINDOW; ++half_window)
{
// end when we have a non empty block
uint64_t cum0 = first_block_offset > 0 ? rct_offsets[first_block_offset] - rct_offsets[first_block_offset - 1] : rct_offsets[0];
@ -6864,19 +6866,24 @@ void wallet2::get_outs(std::vector<std::vector<tools::wallet2::get_outs_entry>>
uint64_t cum1 = last_block_offset > 0 ? rct_offsets[last_block_offset] - rct_offsets[last_block_offset - 1] : rct_offsets[0];
if (cum1 > 1)
break;
if (first_block_offset == 0 && last_block_offset >= rct_offsets.size() - 2)
if (first_block_offset == 0 && last_block_offset >= last_usable_block)
break;
// expand up to bounds
if (first_block_offset > 0)
--first_block_offset;
if (last_block_offset < rct_offsets.size() - 1)
else
return std::numeric_limits<uint64_t>::max(); // bad pick
if (last_block_offset < last_usable_block - CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE)
++last_block_offset;
else
return std::numeric_limits<uint64_t>::max(); // bad pick
}
const uint64_t n_rct = rct_offsets[last_block_offset] - (first_block_offset == 0 ? 0 : rct_offsets[first_block_offset - 1]);
const uint64_t first_rct = first_block_offset == 0 ? 0 : rct_offsets[first_block_offset - 1];
const uint64_t n_rct = rct_offsets[last_block_offset] - first_rct;
if (n_rct == 0)
return rct_offsets[block_offset] ? rct_offsets[block_offset] - 1 : 0;
MDEBUG("Picking 1/" << n_rct << " in " << (last_block_offset - first_block_offset + 1) << " blocks centered around " << block_offset);
return rct_offsets[first_block_offset] + crypto::rand<uint64_t>() % n_rct;
MDEBUG("Picking 1/" << n_rct << " in " << (last_block_offset - first_block_offset + 1) << " blocks centered around " << block_offset + rct_start_height);
return first_rct + crypto::rand<uint64_t>() % n_rct;
};
size_t num_selected_transfers = 0;