wallet2: "output lineup" fake out selection

Based on python code by sarang:
https://github.com/SarangNoether/skunkworks/blob/outputs/outputs/simulate.py
This commit is contained in:
moneromooo-monero 2019-04-02 14:16:45 +00:00
parent 7973fb6a69
commit 35e0a968bd
No known key found for this signature in database
GPG key ID: 686F07454D6CEFC3
3 changed files with 189 additions and 60 deletions

View file

@ -29,7 +29,6 @@
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
#include <numeric>
#include <random>
#include <tuple>
#include <boost/format.hpp>
#include <boost/optional/optional.hpp>
@ -129,7 +128,8 @@ using namespace cryptonote;
#define FIRST_REFRESH_GRANULARITY 1024
#define GAMMA_PICK_HALF_WINDOW 5
#define GAMMA_SHAPE 19.28
#define GAMMA_SCALE (1/1.61)
static const std::string MULTISIG_SIGNATURE_MAGIC = "SigMultisigPkV1";
static const std::string MULTISIG_EXTRA_INFO_MAGIC = "MultisigxV1";
@ -958,6 +958,44 @@ const size_t MAX_SPLIT_ATTEMPTS = 30;
constexpr const std::chrono::seconds wallet2::rpc_timeout;
const char* wallet2::tr(const char* str) { return i18n_translate(str, "tools::wallet2"); }
gamma_picker::gamma_picker(const std::vector<uint64_t> &rct_offsets, double shape, double scale):
rct_offsets(rct_offsets)
{
gamma = std::gamma_distribution<double>(shape, scale);
THROW_WALLET_EXCEPTION_IF(rct_offsets.size() <= CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE, error::wallet_internal_error, "Bad offset calculation");
const size_t blocks_in_a_year = 86400 * 365 / DIFFICULTY_TARGET_V2;
const size_t blocks_to_consider = rct_offsets.size() < blocks_in_a_year;
const size_t outputs_to_consider = rct_offsets.back() - (blocks_to_consider < rct_offsets.size() ? rct_offsets[rct_offsets.size() - blocks_to_consider - 1] : 0);
begin = rct_offsets.data();
end = rct_offsets.data() + rct_offsets.size() - CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE;
num_rct_outputs = *(end - 1);
THROW_WALLET_EXCEPTION_IF(num_rct_outputs == 0, error::wallet_internal_error, "No rct outputs");
average_output_time = DIFFICULTY_TARGET_V2 * rct_offsets.size() / num_rct_outputs; // this assumes constant target over the whole rct range
};
gamma_picker::gamma_picker(const std::vector<uint64_t> &rct_offsets): gamma_picker(rct_offsets, GAMMA_SHAPE, GAMMA_SCALE) {}
uint64_t gamma_picker::pick()
{
double x = gamma(engine);
x = exp(x);
uint64_t output_index = x / average_output_time;
if (output_index >= num_rct_outputs)
return std::numeric_limits<uint64_t>::max(); // bad pick
output_index = num_rct_outputs - 1 - output_index;
const uint64_t *it = std::lower_bound(begin, end, output_index);
THROW_WALLET_EXCEPTION_IF(it == end, error::wallet_internal_error, "output_index not found");
uint64_t index = std::distance(begin, it);
const uint64_t first_rct = index == 0 ? 0 : rct_offsets[index - 1];
const uint64_t n_rct = rct_offsets[index] - first_rct;
if (n_rct == 0)
return std::numeric_limits<uint64_t>::max(); // bad pick
MDEBUG("Picking 1/" << n_rct << " in block " << index);
return first_rct + crypto::rand_idx(n_rct);
};
wallet_keys_unlocker::wallet_keys_unlocker(wallet2 &w, const boost::optional<tools::password_container> &password):
w(w),
locked(password != boost::none)
@ -7562,61 +7600,9 @@ void wallet2::get_outs(std::vector<std::vector<tools::wallet2::get_outs_entry>>
COMMAND_RPC_GET_OUTPUTS_BIN::request req = AUTO_VAL_INIT(req);
COMMAND_RPC_GET_OUTPUTS_BIN::response daemon_resp = AUTO_VAL_INIT(daemon_resp);
struct gamma_engine
{
typedef uint64_t result_type;
static constexpr result_type min() { return 0; }
static constexpr result_type max() { return std::numeric_limits<result_type>::max(); }
result_type operator()() { return crypto::rand<result_type>(); }
} engine;
static const double shape = 19.28/*16.94*/;
//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 > last_usable_block - CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE)
return std::numeric_limits<uint64_t>::max(); // bad pick
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 - 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)
{
// 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];
if (cum0 > 1)
break;
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 >= last_usable_block)
break;
// expand up to bounds
if (first_block_offset > 0)
--first_block_offset;
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 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 + rct_start_height);
return first_rct + crypto::rand_idx(n_rct);
};
std::unique_ptr<gamma_picker> gamma;
if (has_rct_distribution)
gamma.reset(new gamma_picker(rct_offsets));
size_t num_selected_transfers = 0;
for(size_t idx: selected_transfers)
@ -7814,20 +7800,21 @@ void wallet2::get_outs(std::vector<std::vector<tools::wallet2::get_outs_entry>>
const char *type = "";
if (amount == 0 && has_rct_distribution)
{
THROW_WALLET_EXCEPTION_IF(!gamma, error::wallet_internal_error, "No gamma picker");
// gamma distribution
if (num_found -1 < recent_outputs_count + pre_fork_outputs_count)
{
do i = pick_gamma(); while (i >= segregation_limit[amount].first);
do i = gamma->pick(); while (i >= segregation_limit[amount].first);
type = "pre-fork gamma";
}
else if (num_found -1 < recent_outputs_count + pre_fork_outputs_count + post_fork_outputs_count)
{
do i = pick_gamma(); while (i < segregation_limit[amount].first || i >= num_outs);
do i = gamma->pick(); while (i < segregation_limit[amount].first || i >= num_outs);
type = "post-fork gamma";
}
else
{
do i = pick_gamma(); while (i >= num_outs);
do i = gamma->pick(); while (i >= num_outs);
type = "gamma";
}
}

View file

@ -39,6 +39,7 @@
#include <boost/serialization/deque.hpp>
#include <boost/thread/lock_guard.hpp>
#include <atomic>
#include <random>
#include "include_base_utils.h"
#include "cryptonote_basic/account.h"
@ -76,6 +77,30 @@ namespace tools
class wallet2;
class Notify;
class gamma_picker
{
public:
uint64_t pick();
gamma_picker(const std::vector<uint64_t> &rct_offsets);
gamma_picker(const std::vector<uint64_t> &rct_offsets, double shape, double scale);
private:
struct gamma_engine
{
typedef uint64_t result_type;
static constexpr result_type min() { return 0; }
static constexpr result_type max() { return std::numeric_limits<result_type>::max(); }
result_type operator()() { return crypto::rand<result_type>(); }
} engine;
private:
std::gamma_distribution<double> gamma;
const std::vector<uint64_t> &rct_offsets;
const uint64_t *begin, *end;
uint64_t num_rct_outputs;
double average_output_time;
};
class wallet_keys_unlocker
{
public:

View file

@ -101,3 +101,120 @@ TEST(select_outputs, order)
PICK(1); // then the one that's on the same height
}
#define MKOFFSETS(N, n) \
offsets.resize(N); \
size_t n_outs = 0; \
for (auto &offset: offsets) \
{ \
offset = n_outs += (n); \
}
TEST(select_outputs, gamma)
{
std::vector<uint64_t> offsets;
MKOFFSETS(300000, 1);
tools::gamma_picker picker(offsets);
std::vector<double> ages(100000);
double age_scale = 120. * (offsets.size() / (double)n_outs);
for (size_t i = 0; i < ages.size(); )
{
uint64_t o = picker.pick();
if (o >= n_outs)
continue;
ages[i] = (n_outs - 1 - o) * age_scale;
ASSERT_GE(ages[i], 0);
ASSERT_LE(ages[i], offsets.size() * 120);
++i;
}
double median = epee::misc_utils::median(ages);
MDEBUG("median age: " << median / 86400. << " days");
ASSERT_GE(median, 1.3 * 86400);
ASSERT_LE(median, 1.4 * 86400);
}
TEST(select_outputs, density)
{
static const size_t NPICKS = 1000000;
std::vector<uint64_t> offsets;
MKOFFSETS(300000, 1 + (rand() & 0x1f));
tools::gamma_picker picker(offsets);
std::vector<int> picks(/*n_outs*/offsets.size(), 0);
for (int i = 0; i < NPICKS; )
{
uint64_t o = picker.pick();
if (o >= n_outs)
continue;
auto it = std::lower_bound(offsets.begin(), offsets.end(), o);
auto idx = std::distance(offsets.begin(), it);
ASSERT_LT(idx, picks.size());
++picks[idx];
++i;
}
for (int d = 1; d < 0x20; ++d)
{
// count the number of times an output in a block of d outputs was selected
// count how many outputs are in a block of d outputs
size_t count_selected = 0, count_chain = 0;
for (size_t i = 0; i < offsets.size(); ++i)
{
size_t n_outputs = offsets[i] - (i == 0 ? 0 : offsets[i - 1]);
if (n_outputs == d)
{
count_selected += picks[i];
count_chain += d;
}
}
float selected_ratio = count_selected / (float)NPICKS;
float chain_ratio = count_chain / (float)n_outs;
MDEBUG(count_selected << "/" << NPICKS << " outputs selected in blocks of density " << d << ", " << 100.0f * selected_ratio << "%");
MDEBUG(count_chain << "/" << offsets.size() << " outputs in blocks of density " << d << ", " << 100.0f * chain_ratio << "%");
ASSERT_LT(fabsf(selected_ratio - chain_ratio), 0.02f);
}
}
TEST(select_outputs, same_distribution)
{
static const size_t NPICKS = 1000000;
std::vector<uint64_t> offsets;
MKOFFSETS(300000, 1 + (rand() & 0x1f));
tools::gamma_picker picker(offsets);
std::vector<int> chain_picks(offsets.size(), 0);
std::vector<int> output_picks(n_outs, 0);
for (int i = 0; i < NPICKS; )
{
uint64_t o = picker.pick();
if (o >= n_outs)
continue;
auto it = std::lower_bound(offsets.begin(), offsets.end(), o);
auto idx = std::distance(offsets.begin(), it);
ASSERT_LT(idx, chain_picks.size());
++chain_picks[idx];
++output_picks[o];
++i;
}
// scale them both to 0-100
std::vector<int> chain_norm(100, 0), output_norm(100, 0);
for (size_t i = 0; i < output_picks.size(); ++i)
output_norm[i * 100 / output_picks.size()] += output_picks[i];
for (size_t i = 0; i < chain_picks.size(); ++i)
chain_norm[i * 100 / chain_picks.size()] += chain_picks[i];
double max_dev = 0.0, avg_dev = 0.0;
for (size_t i = 0; i < 100; ++i)
{
const double diff = (double)output_norm[i] - (double)chain_norm[i];
double dev = fabs(2.0 * diff / (output_norm[i] + chain_norm[i]));
ASSERT_LT(dev, 0.1);
avg_dev += dev;
}
avg_dev /= 100;
MDEBUG("avg_dev: " << avg_dev);
ASSERT_LT(avg_dev, 0.015);
}