crypto::public_key get_tx_pub_key_from_extra(const std::vector<uint8_t>& tx_extra) {
std::vector<tx_extra_field> tx_extra_fields;
parse_tx_extra(tx_extra, tx_extra_fields);
tx_extra_pub_key pub_key_field;
if (!find_tx_extra_field_by_type(tx_extra_fields, pub_key_field))
return null_pkey;
return pub_key_field.pub_key;
}
bool getPaymentIdFromTxExtra(const std::vector<uint8_t>& extra, crypto::hash& paymentId) {
std::vector<tx_extra_field> tx_extra_fields;
if (!parse_tx_extra(extra, tx_extra_fields)) {
return false;
}
tx_extra_nonce extra_nonce;
if (find_tx_extra_field_by_type(tx_extra_fields, extra_nonce)) {
if (!get_payment_id_from_tx_extra_nonce(extra_nonce.nonce, paymentId)) {
return false;
}
} else {
return false;
}
return true;
}
//---------------------------------------------------------------
bool construct_tx_and_get_tx_key(const account_keys& sender_account_keys, const std::vector<tx_source_entry>& sources, const std::vector<tx_destination_entry>& destinations, std::vector<uint8_t> extra, transaction& tx, uint64_t unlock_time, crypto::secret_key &tx_key, bool rct)
{
std::vector<rct::key> amount_keys;
tx.set_null();
amount_keys.clear();
tx.version = rct ? 2 : 1;
tx.unlock_time = unlock_time;
tx.extra = extra;
keypair txkey = keypair::generate();
remove_field_from_tx_extra(tx.extra, typeid(tx_extra_pub_key));
add_tx_pub_key_to_extra(tx, txkey.pub);
tx_key = txkey.sec;
// if we have a stealth payment id, find it and encrypt it with the tx key now
std::vector<tx_extra_field> tx_extra_fields;
if (parse_tx_extra(tx.extra, tx_extra_fields))
{
tx_extra_nonce extra_nonce;
if (find_tx_extra_field_by_type(tx_extra_fields, extra_nonce))
{
crypto::hash8 payment_id = null_hash8;
if (get_encrypted_payment_id_from_tx_extra_nonce(extra_nonce.nonce, payment_id))
{
LOG_PRINT_L2("Encrypting payment id " << payment_id);
crypto::public_key view_key_pub = get_destination_view_key_pub(destinations, sender_account_keys);
if (view_key_pub == null_pkey)
{
LOG_ERROR("Destinations have to have exactly one output to support encrypted payment ids");
return false;
}
if (!encrypt_payment_id(payment_id, view_key_pub, txkey.sec))
{
LOG_ERROR("Failed to encrypt payment id");
return false;
}
std::string extra_nonce;
set_encrypted_payment_id_to_tx_extra_nonce(extra_nonce, payment_id);
remove_field_from_tx_extra(tx.extra, typeid(tx_extra_nonce));
if (!add_extra_nonce_to_tx_extra(tx.extra, extra_nonce))
{
LOG_ERROR("Failed to add encrypted payment id to tx extra");
return false;
}
LOG_PRINT_L1("Encrypted payment ID: " << payment_id);
}
}
}
else
{
LOG_ERROR("Failed to parse tx extra");
return false;
}
struct input_generation_context_data
{
keypair in_ephemeral;
};
std::vector<input_generation_context_data> in_contexts;
uint64_t summary_inputs_money = 0;
//fill inputs
int idx = -1;
for(const tx_source_entry& src_entr: sources)
{
++idx;
if(src_entr.real_output >= src_entr.outputs.size())
{
LOG_ERROR("real_output index (" << src_entr.real_output << ")bigger than output_keys.size()=" << src_entr.outputs.size());
return false;
}
summary_inputs_money += src_entr.amount;
//key_derivation recv_derivation;
in_contexts.push_back(input_generation_context_data());
keypair& in_ephemeral = in_contexts.back().in_ephemeral;
crypto::key_image img;
if(!generate_key_image_helper(sender_account_keys, src_entr.real_out_tx_key, src_entr.real_output_in_tx_index, in_ephemeral, img))
return false;
//check that derivated key is equal with real output key
if( !(in_ephemeral.pub == src_entr.outputs[src_entr.real_output].second.dest) )
{
LOG_ERROR("derived public key mismatch with output public key at index " << idx << ", real out " << src_entr.real_output << "! "<< ENDL << "derived_key:"
<< string_tools::pod_to_hex(in_ephemeral.pub) << ENDL << "real output_public_key:"
<< string_tools::pod_to_hex(src_entr.outputs[src_entr.real_output].second) );
LOG_ERROR("amount " << src_entr.amount << ", rct " << src_entr.rct);
LOG_ERROR("tx pubkey " << src_entr.real_out_tx_key << ", real_output_in_tx_index " << src_entr.real_output_in_tx_index);
return false;
}
//put key image into tx input
txin_to_key input_to_key;
input_to_key.amount = src_entr.amount;
input_to_key.k_image = img;
//fill outputs array and use relative offsets
for(const tx_source_entry::output_entry& out_entry: src_entr.outputs)
input_to_key.key_offsets.push_back(out_entry.first);
input_to_key.key_offsets = absolute_output_offsets_to_relative(input_to_key.key_offsets);
tx.vin.push_back(input_to_key);
}
// "Shuffle" outs
std::vector<tx_destination_entry> shuffled_dsts(destinations);
std::sort(shuffled_dsts.begin(), shuffled_dsts.end(), [](const tx_destination_entry& de1, const tx_destination_entry& de2) { return de1.amount < de2.amount; } );
uint64_t summary_outs_money = 0;
//fill outputs
size_t output_index = 0;
for(const tx_destination_entry& dst_entr: shuffled_dsts)
{
CHECK_AND_ASSERT_MES(dst_entr.amount > 0 || tx.version > 1, false, "Destination with wrong amount: " << dst_entr.amount);
crypto::key_derivation derivation;
crypto::public_key out_eph_public_key;
bool r = crypto::generate_key_derivation(dst_entr.addr.m_view_public_key, txkey.sec, derivation);
CHECK_AND_ASSERT_MES(r, false, "at creation outs: failed to generate_key_derivation(" << dst_entr.addr.m_view_public_key << ", " << txkey.sec << ")");
if (tx.version > 1)
{
crypto::secret_key scalar1;
crypto::derivation_to_scalar(derivation, output_index, scalar1);
amount_keys.push_back(rct::sk2rct(scalar1));
}
r = crypto::derive_public_key(derivation, output_index, dst_entr.addr.m_spend_public_key, out_eph_public_key);
CHECK_AND_ASSERT_MES(r, false, "at creation outs: failed to derive_public_key(" << derivation << ", " << output_index << ", "<< dst_entr.addr.m_spend_public_key << ")");
tx_out out;
out.amount = dst_entr.amount;
txout_to_key tk;
tk.key = out_eph_public_key;
out.target = tk;
tx.vout.push_back(out);
output_index++;
summary_outs_money += dst_entr.amount;
}
//check money
if(summary_outs_money > summary_inputs_money )
{
LOG_ERROR("Transaction inputs money ("<< summary_inputs_money << ") less than outputs money (" << summary_outs_money << ")");
return false;
}
// check for watch only wallet
bool zero_secret_key = true;
for (size_t i = 0; i < sizeof(sender_account_keys.m_spend_secret_key); ++i)
zero_secret_key &= (sender_account_keys.m_spend_secret_key.data[i] == 0);
if (zero_secret_key)
{
MDEBUG("Null secret key, skipping signatures");
}
if (tx.version == 1)
{
//generate ring signatures
crypto::hash tx_prefix_hash;
get_transaction_prefix_hash(tx, tx_prefix_hash);
std::stringstream ss_ring_s;
size_t i = 0;
for(const tx_source_entry& src_entr: sources)
{
ss_ring_s << "pub_keys:" << ENDL;
std::vector<const crypto::public_key*> keys_ptrs;
std::vector<crypto::public_key> keys(src_entr.outputs.size());
size_t ii = 0;
for(const tx_source_entry::output_entry& o: src_entr.outputs)
{
keys[ii] = rct2pk(o.second.dest);
keys_ptrs.push_back(&keys[ii]);
ss_ring_s << o.second.dest << ENDL;
++ii;
}
tx.signatures.push_back(std::vector<crypto::signature>());
std::vector<crypto::signature>& sigs = tx.signatures.back();
sigs.resize(src_entr.outputs.size());
if (!zero_secret_key)
crypto::generate_ring_signature(tx_prefix_hash, boost::get<txin_to_key>(tx.vin[i]).k_image, keys_ptrs, in_contexts[i].in_ephemeral.sec, src_entr.real_output, sigs.data());
ss_ring_s << "signatures:" << ENDL;
std::for_each(sigs.begin(), sigs.end(), [&](const crypto::signature& s){ss_ring_s << s << ENDL;});
ss_ring_s << "prefix_hash:" << tx_prefix_hash << ENDL << "in_ephemeral_key: " << in_contexts[i].in_ephemeral.sec << ENDL << "real_output: " << src_entr.real_output << ENDL;
i++;
}
MCINFO("construct_tx", "transaction_created: " << get_transaction_hash(tx) << ENDL << obj_to_json_str(tx) << ENDL << ss_ring_s.str());
}
else
{
size_t n_total_outs = sources[0].outputs.size(); // only for non-simple rct
// the non-simple version is slightly smaller, but assumes all real inputs
// are on the same index, so can only be used if there just one ring.
bool use_simple_rct = sources.size() > 1;
if (!use_simple_rct)
{
// non simple ringct requires all real inputs to be at the same index for all inputs
for(const tx_source_entry& src_entr: sources)
{
if(src_entr.real_output != sources.begin()->real_output)
{
LOG_ERROR("All inputs must have the same index for non-simple ringct");
return false;
}
}
// enforce same mixin for all outputs
for (size_t i = 1; i < sources.size(); ++i) {
if (n_total_outs != sources[i].outputs.size()) {
LOG_ERROR("Non-simple ringct transaction has varying mixin");
return false;
}
}
}
uint64_t amount_in = 0, amount_out = 0;
rct::ctkeyV inSk;
// mixRing indexing is done the other way round for simple
rct::ctkeyM mixRing(use_simple_rct ? sources.size() : n_total_outs);
rct::keyV destinations;
std::vector<uint64_t> inamounts, outamounts;
std::vector<unsigned int> index;
for (size_t i = 0; i < sources.size(); ++i)
{
rct::ctkey ctkey;
amount_in += sources[i].amount;
inamounts.push_back(sources[i].amount);
index.push_back(sources[i].real_output);
// inSk: (secret key, mask)
ctkey.dest = rct::sk2rct(in_contexts[i].in_ephemeral.sec);
ctkey.mask = sources[i].mask;
inSk.push_back(ctkey);
// inPk: (public key, commitment)
// will be done when filling in mixRing
}
for (size_t i = 0; i < tx.vout.size(); ++i)
{
destinations.push_back(rct::pk2rct(boost::get<txout_to_key>(tx.vout[i].target).key));
outamounts.push_back(tx.vout[i].amount);
amount_out += tx.vout[i].amount;
}
if (use_simple_rct)
{
// mixRing indexing is done the other way round for simple
for (size_t i = 0; i < sources.size(); ++i)
{
mixRing[i].resize(sources[i].outputs.size());
for (size_t n = 0; n < sources[i].outputs.size(); ++n)
{
mixRing[i][n] = sources[i].outputs[n].second;
}
}
}
else
{
for (size_t i = 0; i < n_total_outs; ++i) // same index assumption
{
mixRing[i].resize(sources.size());
for (size_t n = 0; n < sources.size(); ++n)
{
mixRing[i][n] = sources[n].outputs[i].second;
}
}
}
// fee
if (!use_simple_rct && amount_in > amount_out)
outamounts.push_back(amount_in - amount_out);
// zero out all amounts to mask rct outputs, real amounts are now encrypted
for (size_t i = 0; i < tx.vin.size(); ++i)
{
if (sources[i].rct)
boost::get<txin_to_key>(tx.vin[i]).amount = 0;
}
for (size_t i = 0; i < tx.vout.size(); ++i)
tx.vout[i].amount = 0;
crypto::hash tx_prefix_hash;
get_transaction_prefix_hash(tx, tx_prefix_hash);
rct::ctkeyV outSk;
if (use_simple_rct)
tx.rct_signatures = rct::genRctSimple(rct::hash2rct(tx_prefix_hash), inSk, destinations, inamounts, outamounts, amount_in - amount_out, mixRing, amount_keys, index, outSk);
else
tx.rct_signatures = rct::genRct(rct::hash2rct(tx_prefix_hash), inSk, destinations, outamounts, mixRing, amount_keys, sources[0].real_output, outSk); // same index assumption
CHECK_AND_ASSERT_MES(tx.vout.size() == outSk.size(), false, "outSk size does not match vout");
MCINFO("construct_tx", "transaction_created: " << get_transaction_hash(tx) << ENDL << obj_to_json_str(tx) << ENDL);
}
tx.invalidate_hashes();
return true;
}
bool get_mm_tag_from_extra(const std::vector<uint8_t>& tx_extra, tx_extra_merge_mining_tag& mm_tag) {
std::vector<tx_extra_field> tx_extra_fields;
parse_tx_extra(tx_extra, tx_extra_fields);
return find_tx_extra_field_by_type(tx_extra_fields, mm_tag);
}
