mymonero-core-cpp/src/monero_transfer_utils.cpp

//
//  monero_transfer_utils.cpp
//  Copyright © 2018 MyMonero. All rights reserved.
//
//  All rights reserved.
//
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//  2. Redistributions in binary form must reproduce the above copyright notice, this list
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//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
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//  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
//
//
#include "monero_transfer_utils.hpp"
#include "wallet_errors.h"
//
//using namespace std;
//using namespace crypto;
//using namespace epee;
using namespace cryptonote;
//using namespace tools; // for error::
using namespace monero_transfer_utils;
using namespace monero_fork_rules;
//
// Protocol / Defaults
uint32_t monero_transfer_utils::fixed_ringsize()
{
	return 7; // best practice is to conform to fixed ring size
}
uint32_t monero_transfer_utils::fixed_mixinsize()
{
	return monero_transfer_utils::fixed_ringsize() - 1;
}
uint32_t monero_transfer_utils::default_priority()
{
	return 1; // lowest (TODO: declare centrally)
}
//
// Fee estimation
uint64_t monero_transfer_utils::estimated_tx_network_fee(
	uint64_t fee_per_kb,
	uint32_t priority,
	network_type nettype,
	use_fork_rules_fn_type use_fork_rules_fn
) {
	bool bulletproof = use_fork_rules_fn(get_bulletproof_fork(), 0);
	uint64_t fee_multiplier = get_fee_multiplier(priority, default_priority(), get_fee_algorithm(use_fork_rules_fn), use_fork_rules_fn);
	std::vector<uint8_t> extra; // blank extra
	size_t est_tx_size = estimate_rct_tx_size(2, fixed_mixinsize(), 2, extra.size(), bulletproof); // typically ~14kb post-rct, pre-bulletproofs
	uint64_t estimated_fee = calculate_fee(fee_per_kb, est_tx_size, fee_multiplier);
	//
	return estimated_fee;
}
uint64_t monero_transfer_utils::get_upper_transaction_size_limit(
	uint64_t upper_transaction_size_limit__or_0_for_default,
	use_fork_rules_fn_type use_fork_rules_fn
) {
	if (upper_transaction_size_limit__or_0_for_default > 0)
		return upper_transaction_size_limit__or_0_for_default;
	uint64_t full_reward_zone = use_fork_rules_fn(5, 10) ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : use_fork_rules_fn(2, 10) ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 : CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V1;
	return full_reward_zone - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE;
}
uint64_t monero_transfer_utils::get_fee_multiplier(
	uint32_t priority,
	uint32_t default_priority,
	int fee_algorithm,
	use_fork_rules_fn_type use_fork_rules_fn
) {
	static const uint64_t old_multipliers[3] = {1, 2, 3};
	static const uint64_t new_multipliers[3] = {1, 20, 166};
	static const uint64_t newer_multipliers[4] = {1, 4, 20, 166};

	if (fee_algorithm == -1)
		fee_algorithm = get_fee_algorithm(use_fork_rules_fn);

	// 0 -> default (here, x1 till fee algorithm 2, x4 from it)
	if (priority == 0)
		priority = default_priority;
	if (priority == 0)
	{
		if (fee_algorithm >= 2)
			priority = 2;
		else
			priority = 1;
	}

	// 1 to 3/4 are allowed as priorities
	uint32_t max_priority = (fee_algorithm >= 2) ? 4 : 3;
	if (priority >= 1 && priority <= max_priority)
	{
		switch (fee_algorithm)
		{
			case 0: return old_multipliers[priority-1];
			case 1: return new_multipliers[priority-1];
			case 2: return newer_multipliers[priority-1];
			default: THROW_WALLET_EXCEPTION_IF (true, error::invalid_priority);
		}
	}

	THROW_WALLET_EXCEPTION_IF (false, error::invalid_priority);
	return 1;
}
int monero_transfer_utils::get_fee_algorithm(use_fork_rules_fn_type use_fork_rules_fn)
{
	// changes at v3 and v5
	if (use_fork_rules_fn(5, 0))
		return 2;
	if (use_fork_rules_fn(3, -720 * 14))
		return 1;
	return 0;
}
size_t monero_transfer_utils::estimate_rct_tx_size(int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof)
{
	size_t size = 0;

	// tx prefix

	// first few bytes
	size += 1 + 6;

	// vin
	size += n_inputs * (1+6+(mixin+1)*2+32);

	// vout
	size += n_outputs * (6+32);

	// extra
	size += extra_size;

	// rct signatures

	// type
	size += 1;

	// rangeSigs
	if (bulletproof)
		size += ((2*6 + 4 + 5)*32 + 3) * n_outputs;
	else
		size += (2*64*32+32+64*32) * n_outputs;

	// MGs
	size += n_inputs * (64 * (mixin+1) + 32);

	// mixRing - not serialized, can be reconstructed
	/* size += 2 * 32 * (mixin+1) * n_inputs; */

	// pseudoOuts
	size += 32 * n_inputs;
	// ecdhInfo
	size += 2 * 32 * n_outputs;
	// outPk - only commitment is saved
	size += 32 * n_outputs;
	// txnFee
	size += 4;

	LOG_PRINT_L2("estimated rct tx size for " << n_inputs << " with ring size " << (mixin+1) << " and " << n_outputs << ": " << size << " (" << ((32 * n_inputs/*+1*/) + 2 * 32 * (mixin+1) * n_inputs + 32 * n_outputs) << " saved)");
	return size;
}
size_t monero_transfer_utils::estimate_tx_size(bool use_rct, int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof)
{
	if (use_rct)
		return estimate_rct_tx_size(n_inputs, mixin, n_outputs + 1, extra_size, bulletproof);
	else
		return n_inputs * (mixin+1) * APPROXIMATE_INPUT_BYTES + extra_size;
}
//
uint64_t monero_transfer_utils::calculate_fee(uint64_t fee_per_kb, size_t bytes, uint64_t fee_multiplier)
{
	uint64_t kB = (bytes + 1023) / 1024;
	return kB * fee_per_kb * fee_multiplier;
}
uint64_t monero_transfer_utils::calculate_fee(uint64_t fee_per_kb, const cryptonote::blobdata &blob, uint64_t fee_multiplier)
{
	return calculate_fee(fee_per_kb, blob.size(), fee_multiplier);
}
//
// Transfer parsing/derived properties
bool monero_transfer_utils::is_transfer_unlocked(
	uint64_t unlock_time,
	uint64_t block_height,
	uint64_t blockchain_size, /* extracting wallet2->m_blockchain.size() / m_local_bc_height */
	network_type nettype
) {
	if(!is_tx_spendtime_unlocked(unlock_time, block_height, blockchain_size, nettype))
		return false;

	if(block_height + CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE > blockchain_size)
		return false;

	return true;
}
bool monero_transfer_utils::is_tx_spendtime_unlocked(
	uint64_t unlock_time,
	uint64_t block_height,
	uint64_t blockchain_size,
	network_type nettype
) {
	if(unlock_time < CRYPTONOTE_MAX_BLOCK_NUMBER)
	{
		//interpret as block index
		if(blockchain_size-1 + CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_BLOCKS >= unlock_time)
			return true;
		else
			return false;
	}else
	{
		//interpret as time
		uint64_t current_time = static_cast<uint64_t>(time(NULL));
		// XXX: this needs to be fast, so we'd need to get the starting heights
		// from the daemon to be correct once voting kicks in
		uint64_t v2height = nettype == TESTNET ? 624634 : nettype == STAGENET ? (uint64_t)-1/*TODO*/ : 1009827;
		uint64_t leeway = block_height < v2height ? CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_SECONDS_V1 : CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_SECONDS_V2;
		if(current_time + leeway >= unlock_time)
			return true;
		else
			return false;
	}
	return false;
}
//
// Constructing transactions
std::string monero_transfer_utils::new_dummy_address_string_for_rct_tx(network_type nettype)
{
	cryptonote::account_base account;
	account.generate();
	//
	return account.get_public_address_str(nettype);
}