/* * This file is part of the TREZOR project. * * Copyright (C) 2014 Pavol Rusnak * * This library is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library. If not, see . */ #include "signing.h" #include "fsm.h" #include "layout2.h" #include "messages.h" #include "transaction.h" #include "ecdsa.h" #include "protect.h" #include "crypto.h" #include "secp256k1.h" #include "gettext.h" static uint32_t inputs_count; static uint32_t outputs_count; static const CoinType *coin; static const HDNode *root; static HDNode node; static bool signing = false; enum { STAGE_REQUEST_1_INPUT, STAGE_REQUEST_2_PREV_META, STAGE_REQUEST_2_PREV_INPUT, STAGE_REQUEST_2_PREV_OUTPUT, STAGE_REQUEST_2_PREV_EXTRADATA, STAGE_REQUEST_3_OUTPUT, STAGE_REQUEST_4_INPUT, STAGE_REQUEST_4_OUTPUT, STAGE_REQUEST_SEGWIT_INPUT, STAGE_REQUEST_5_OUTPUT, STAGE_REQUEST_SEGWIT_WITNESS } signing_stage; static uint32_t idx1, idx2; static uint32_t signatures; static TxRequest resp; static TxInputType input; static TxOutputBinType bin_output; static TxStruct to, tp, ti; static SHA256_CTX hashers[3]; static uint8_t privkey[32], pubkey[33], sig[64]; static uint8_t hash_prevouts[32], hash_sequence[32],hash_outputs[32]; static uint8_t hash_check[32]; static uint64_t to_spend, authorized_amount, spending, change_spend; static uint32_t version = 1; static uint32_t lock_time = 0; static uint32_t next_nonsegwit_input; static uint32_t progress, progress_step, progress_meta_step; static bool multisig_fp_set, multisig_fp_mismatch; static uint8_t multisig_fp[32]; static uint32_t in_address_n[8]; static size_t in_address_n_count; enum { SIGHASH_ALL = 1, SIGHASH_FORKID = 0x40, }; /* progress_step/meta_step are fixed point numbers, giving the * progress per input in permille with these many additional bits. */ #define PROGRESS_PRECISION 16 /* Workflow of streamed signing The STAGE_ constants describe the signing_stage when request is sent. I - input O - output Phase1 - check inputs, previous transactions, and outputs - ask for confirmations - check fee ========================================================= foreach I (idx1): Request I STAGE_REQUEST_1_INPUT Add I to segwit hash_prevouts, hash_sequence Add I to TransactionChecksum (prevout and type) If not segwit, Calculate amount of I: Request prevhash I, META STAGE_REQUEST_2_PREV_META foreach prevhash I (idx2): Request prevhash I STAGE_REQUEST_2_PREV_INPUT foreach prevhash O (idx2): Request prevhash O STAGE_REQUEST_2_PREV_OUTPUT Add amount of prevhash O (which is amount of I) Request prevhash extra data (if applicable) STAGE_REQUEST_2_PREV_EXTRADATA Calculate hash of streamed tx, compare to prevhash I foreach O (idx1): Request O STAGE_REQUEST_3_OUTPUT Add O to TransactionChecksum Display output Ask for confirmation Check tx fee Ask for confirmation Phase2: sign inputs, check that nothing changed =============================================== foreach I (idx1): // input to sign if (idx1 is segwit) Request I STAGE_REQUEST_SEGWIT_INPUT Return serialized input chunk else foreach I (idx2): Request I STAGE_REQUEST_4_INPUT If idx1 == idx2 Remember key for signing Fill scriptsig Add I to StreamTransactionSign Add I to TransactionChecksum foreach O (idx2): Request O STAGE_REQUEST_4_OUTPUT Add O to StreamTransactionSign Add O to TransactionChecksum Compare TransactionChecksum with checksum computed in Phase 1 If different: Failure Sign StreamTransactionSign Return signed chunk foreach O (idx1): Request O STAGE_REQUEST_5_OUTPUT Rewrite change address Return O Phase3: sign segwit inputs, check that nothing changed =============================================== foreach I (idx1): // input to sign Request I STAGE_REQUEST_SEGWIT_WITNESS Check amount Sign segwit prevhash, sequence, amount, outputs Return witness */ void send_req_1_input(void) { signing_stage = STAGE_REQUEST_1_INPUT; resp.has_request_type = true; resp.request_type = RequestType_TXINPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx1; msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_2_prev_meta(void) { signing_stage = STAGE_REQUEST_2_PREV_META; resp.has_request_type = true; resp.request_type = RequestType_TXMETA; resp.has_details = true; resp.details.has_tx_hash = true; resp.details.tx_hash.size = input.prev_hash.size; memcpy(resp.details.tx_hash.bytes, input.prev_hash.bytes, input.prev_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_2_prev_input(void) { signing_stage = STAGE_REQUEST_2_PREV_INPUT; resp.has_request_type = true; resp.request_type = RequestType_TXINPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx2; resp.details.has_tx_hash = true; resp.details.tx_hash.size = input.prev_hash.size; memcpy(resp.details.tx_hash.bytes, input.prev_hash.bytes, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_2_prev_output(void) { signing_stage = STAGE_REQUEST_2_PREV_OUTPUT; resp.has_request_type = true; resp.request_type = RequestType_TXOUTPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx2; resp.details.has_tx_hash = true; resp.details.tx_hash.size = input.prev_hash.size; memcpy(resp.details.tx_hash.bytes, input.prev_hash.bytes, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_2_prev_extradata(uint32_t chunk_offset, uint32_t chunk_len) { signing_stage = STAGE_REQUEST_2_PREV_EXTRADATA; resp.has_request_type = true; resp.request_type = RequestType_TXEXTRADATA; resp.has_details = true; resp.details.has_extra_data_offset = true; resp.details.extra_data_offset = chunk_offset; resp.details.has_extra_data_len = true; resp.details.extra_data_len = chunk_len; resp.details.has_tx_hash = true; resp.details.tx_hash.size = input.prev_hash.size; memcpy(resp.details.tx_hash.bytes, input.prev_hash.bytes, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_3_output(void) { signing_stage = STAGE_REQUEST_3_OUTPUT; resp.has_request_type = true; resp.request_type = RequestType_TXOUTPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx1; msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_4_input(void) { signing_stage = STAGE_REQUEST_4_INPUT; resp.has_request_type = true; resp.request_type = RequestType_TXINPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx2; msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_4_output(void) { signing_stage = STAGE_REQUEST_4_OUTPUT; resp.has_request_type = true; resp.request_type = RequestType_TXOUTPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx2; msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_segwit_input(void) { signing_stage = STAGE_REQUEST_SEGWIT_INPUT; resp.has_request_type = true; resp.request_type = RequestType_TXINPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx1; msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_segwit_witness(void) { signing_stage = STAGE_REQUEST_SEGWIT_WITNESS; resp.has_request_type = true; resp.request_type = RequestType_TXINPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx1; msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_5_output(void) { signing_stage = STAGE_REQUEST_5_OUTPUT; resp.has_request_type = true; resp.request_type = RequestType_TXOUTPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx1; msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_finished(void) { resp.has_request_type = true; resp.request_type = RequestType_TXFINISHED; msg_write(MessageType_MessageType_TxRequest, &resp); } void phase1_request_next_input(void) { if (idx1 < inputs_count - 1) { idx1++; send_req_1_input(); } else { // compute segwit hashPrevouts & hashSequence sha256_Final(&hashers[0], hash_prevouts); sha256_Raw(hash_prevouts, 32, hash_prevouts); sha256_Final(&hashers[1], hash_sequence); sha256_Raw(hash_sequence, 32, hash_sequence); sha256_Final(&hashers[2], hash_check); // init hashOutputs sha256_Init(&hashers[0]); idx1 = 0; send_req_3_output(); } } void phase2_request_next_input(void) { if (idx1 == next_nonsegwit_input) { idx2 = 0; send_req_4_input(); } else { send_req_segwit_input(); } } void extract_input_bip32_path(const TxInputType *tinput) { if (in_address_n_count == (size_t) -1) { return; } size_t count = tinput->address_n_count; if (count < 1) { // no change address allowed in_address_n_count = (size_t) -1; return; } if (in_address_n_count == 0) { // initialize in_address_n on first input seen in_address_n_count = count; if (count > 2) { // if longer than 2 elements, store first N - 2 memcpy(in_address_n, tinput->address_n, (count - 2) * sizeof(uint32_t)); } return; } // check whether they are same length if (in_address_n_count != count) { in_address_n_count = (size_t) -1; return; } if (count > 2 && memcmp(in_address_n, tinput->address_n, (count - 2) * sizeof(uint32_t)) != 0) { // mismatch -> no change address allowed in_address_n_count = (size_t) -1; return; } } #define MAX_BIP32_LAST_ELEMENT 1000000 bool check_change_bip32_path(const TxOutputType *toutput) { size_t count = toutput->address_n_count; if (count < 1 || in_address_n_count < 1) { return 0; } if (count != in_address_n_count) { return 0; } if (toutput->address_n[count - 1] > MAX_BIP32_LAST_ELEMENT) { return 0; } if (count >= 2) { if (0 != memcmp(in_address_n, toutput->address_n, (count - 2) * sizeof(uint32_t)) || toutput->address_n[count - 2] != 1) { return 0; } } return 1; } bool compile_input_script_sig(TxInputType *tinput) { if (!multisig_fp_mismatch) { // check that this is still multisig uint8_t h[32]; if (tinput->script_type != InputScriptType_SPENDMULTISIG || cryptoMultisigFingerprint(&(tinput->multisig), h) == 0 || memcmp(multisig_fp, h, 32) != 0) { // Transaction has changed during signing return false; } } if (in_address_n_count >= 1) { // check that input address didn't change size_t count = tinput->address_n_count; if (count != in_address_n_count) { return false; } if (count >= 2 && 0 != memcmp(in_address_n, tinput->address_n, (count - 2) * sizeof(uint32_t))) { return false; } } memcpy(&node, root, sizeof(HDNode)); if (hdnode_private_ckd_cached(&node, tinput->address_n, tinput->address_n_count, NULL) == 0) { // Failed to derive private key return false; } hdnode_fill_public_key(&node); if (tinput->has_multisig) { tinput->script_sig.size = compile_script_multisig(&(tinput->multisig), tinput->script_sig.bytes); } else { // SPENDADDRESS uint8_t hash[20]; ecdsa_get_pubkeyhash(node.public_key, hash); tinput->script_sig.size = compile_script_sig(coin->address_type, hash, tinput->script_sig.bytes); } return tinput->script_sig.size > 0; } void signing_init(uint32_t _inputs_count, uint32_t _outputs_count, const CoinType *_coin, const HDNode *_root, uint32_t _version, uint32_t _lock_time) { inputs_count = _inputs_count; outputs_count = _outputs_count; coin = _coin; root = _root; version = _version; lock_time = _lock_time; signatures = 0; idx1 = 0; to_spend = 0; spending = 0; change_spend = 0; authorized_amount = 0; memset(&input, 0, sizeof(TxInputType)); memset(&resp, 0, sizeof(TxRequest)); signing = true; progress = 0; // we step by 500/inputs_count per input in phase1 and phase2 // this means 50 % per phase. progress_step = (500 << PROGRESS_PRECISION) / inputs_count; in_address_n_count = 0; multisig_fp_set = false; multisig_fp_mismatch = false; next_nonsegwit_input = 0xffffffff; tx_init(&to, inputs_count, outputs_count, version, lock_time, 0, false); // segwit hashes for hashPrevouts and hashSequence sha256_Init(&hashers[0]); sha256_Init(&hashers[1]); sha256_Init(&hashers[2]); layoutProgressSwipe(_("Signing transaction"), 0); send_req_1_input(); } #define MIN(a,b) (((a)<(b))?(a):(b)) static bool signing_check_input(TxInputType *txinput) { /* compute multisig fingerprint */ /* (if all input share the same fingerprint, outputs having the same fingerprint will be considered as change outputs) */ if (txinput->has_multisig && !multisig_fp_mismatch && txinput->script_type == InputScriptType_SPENDMULTISIG) { uint8_t h[32]; if (cryptoMultisigFingerprint(&txinput->multisig, h) == 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Error computing multisig fingerprint")); signing_abort(); return false; } if (multisig_fp_set) { if (memcmp(multisig_fp, h, 32) != 0) { multisig_fp_mismatch = true; } } else { memcpy(multisig_fp, h, 32); multisig_fp_set = true; } } else { // single signature multisig_fp_mismatch = true; } // remember the input bip32 path // change addresses must use the same bip32 path as all inputs extract_input_bip32_path(txinput); // compute segwit hashPrevouts & hashSequence tx_prevout_hash(&hashers[0], txinput); tx_sequence_hash(&hashers[1], txinput); // hash prevout and script type to check it later (relevant for fee computation) tx_prevout_hash(&hashers[2], txinput); sha256_Update(&hashers[2], &txinput->script_type, sizeof(&txinput->script_type)); return true; } // check if the hash of the prevtx matches static bool signing_check_prevtx_hash(void) { uint8_t hash[32]; tx_hash_final(&tp, hash, true); if (memcmp(hash, input.prev_hash.bytes, 32) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Encountered invalid prevhash")); signing_abort(); return false; } phase1_request_next_input(); return true; } static bool signing_check_output(TxOutputType *txoutput) { // Phase1: Check outputs // add it to hash_outputs // ask user for permission // check for change address bool is_change = false; if (txoutput->address_n_count > 0) { if (txoutput->has_address) { fsm_sendFailure(FailureType_Failure_DataError, _("Address in change output")); signing_abort(); return false; } /* * For multisig check that all inputs are multisig */ if (txoutput->has_multisig) { uint8_t h[32]; if (multisig_fp_set && !multisig_fp_mismatch && cryptoMultisigFingerprint(&(txoutput->multisig), h) && memcmp(multisig_fp, h, 32) == 0) { is_change = check_change_bip32_path(txoutput); } } else { is_change = check_change_bip32_path(txoutput); } /* * only allow segwit change if amount is smaller than what segwit inputs paid. */ if ((txoutput->script_type == OutputScriptType_PAYTOWITNESS || txoutput->script_type == OutputScriptType_PAYTOP2SHWITNESS) && txoutput->amount > authorized_amount) { is_change = false; } } if (is_change) { if (change_spend == 0) { // not set change_spend = txoutput->amount; } else { fsm_sendFailure(FailureType_Failure_DataError, _("Only one change output allowed")); signing_abort(); return false; } } if (spending + txoutput->amount < spending) { fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow")); signing_abort(); return false; } spending += txoutput->amount; int co = compile_output(coin, root, txoutput, &bin_output, !is_change); if (!is_change) { layoutProgress(_("Signing transaction"), progress); } if (co < 0) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } else if (co == 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile output")); signing_abort(); return false; } // compute segwit hashOuts tx_output_hash(&hashers[0], &bin_output); return true; } static bool signing_check_fee(void) { // check fees if (spending > to_spend) { fsm_sendFailure(FailureType_Failure_NotEnoughFunds, _("Not enough funds")); signing_abort(); return false; } uint64_t fee = to_spend - spending; uint64_t tx_est_size_kb = (transactionEstimateSize(inputs_count, outputs_count) + 999) / 1000; if (fee > tx_est_size_kb * coin->maxfee_kb) { layoutFeeOverThreshold(coin, fee); if (!protectButton(ButtonRequestType_ButtonRequest_FeeOverThreshold, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } layoutProgress(_("Signing transaction"), progress); } // last confirmation layoutConfirmTx(coin, to_spend - change_spend, fee); if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } return true; } static void phase1_request_next_output(void) { if (idx1 < outputs_count - 1) { idx1++; send_req_3_output(); } else { sha256_Final(&hashers[0], hash_outputs); sha256_Raw(hash_outputs, 32, hash_outputs); if (!signing_check_fee()) { return; } // Everything was checked, now phase 2 begins and the transaction is signed. progress_meta_step = progress_step / (inputs_count + outputs_count); layoutProgress(_("Signing transaction"), progress); idx1 = 0; phase2_request_next_input(); } } static void signing_hash_bip143(const TxInputType *txinput, uint8_t sighash, uint32_t forkid, uint8_t *hash) { uint32_t hash_type = (forkid << 8) | sighash; sha256_Init(&hashers[0]); sha256_Update(&hashers[0], (const uint8_t *)&version, 4); sha256_Update(&hashers[0], hash_prevouts, 32); sha256_Update(&hashers[0], hash_sequence, 32); tx_prevout_hash(&hashers[0], txinput); tx_script_hash(&hashers[0], txinput->script_sig.size, txinput->script_sig.bytes); sha256_Update(&hashers[0], (const uint8_t*) &txinput->amount, 8); tx_sequence_hash(&hashers[0], txinput); sha256_Update(&hashers[0], hash_outputs, 32); sha256_Update(&hashers[0], (const uint8_t*) &lock_time, 4); sha256_Update(&hashers[0], (const uint8_t*) &hash_type, 4); sha256_Final(&hashers[0], hash); sha256_Raw(hash, 32, hash); } static bool signing_sign_hash(TxInputType *txinput, const uint8_t* private_key, const uint8_t *public_key, const uint8_t *hash, uint8_t sighash) { resp.serialized.has_signature_index = true; resp.serialized.signature_index = idx1; resp.serialized.has_signature = true; resp.serialized.has_serialized_tx = true; if (ecdsa_sign_digest(&secp256k1, private_key, hash, sig, NULL, NULL) != 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Signing failed")); signing_abort(); return false; } resp.serialized.signature.size = ecdsa_sig_to_der(sig, resp.serialized.signature.bytes); if (txinput->has_multisig) { // fill in the signature int pubkey_idx = cryptoMultisigPubkeyIndex(&(txinput->multisig), public_key); if (pubkey_idx < 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Pubkey not found in multisig script")); signing_abort(); return false; } memcpy(txinput->multisig.signatures[pubkey_idx].bytes, resp.serialized.signature.bytes, resp.serialized.signature.size); txinput->multisig.signatures[pubkey_idx].size = resp.serialized.signature.size; txinput->script_sig.size = serialize_script_multisig(&(txinput->multisig), sighash, txinput->script_sig.bytes); if (txinput->script_sig.size == 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize multisig script")); signing_abort(); return false; } } else { // SPENDADDRESS txinput->script_sig.size = serialize_script_sig(resp.serialized.signature.bytes, resp.serialized.signature.size, public_key, 33, sighash, txinput->script_sig.bytes); } return true; } static bool signing_sign_input(void) { uint8_t hash[32]; sha256_Final(&hashers[0], hash); sha256_Raw(hash, 32, hash); if (memcmp(hash, hash_outputs, 32) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return false; } uint8_t sighash = SIGHASH_ALL; tx_hash_final(&ti, hash, false); resp.has_serialized = true; if (!signing_sign_hash(&input, privkey, pubkey, hash, sighash)) return false; resp.serialized.serialized_tx.size = tx_serialize_input(&to, &input, resp.serialized.serialized_tx.bytes); return true; } static bool signing_sign_segwit_input(TxInputType *txinput) { // idx1: index to sign uint8_t hash[32]; if (txinput->script_type == InputScriptType_SPENDWITNESS || txinput->script_type == InputScriptType_SPENDP2SHWITNESS) { // disable native segwit for now if (txinput->script_type == InputScriptType_SPENDWITNESS) { fsm_sendFailure(FailureType_Failure_DataError, _("Native segwit is disabled")); signing_abort(); return false; } if (!compile_input_script_sig(txinput)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile input")); signing_abort(); return false; } if (txinput->amount > authorized_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return false; } authorized_amount -= txinput->amount; signing_hash_bip143(txinput, SIGHASH_ALL, 0, hash); resp.has_serialized = true; if (!signing_sign_hash(txinput, node.private_key, node.public_key, hash, SIGHASH_ALL)) return false; if (txinput->has_multisig) { uint32_t r = 1; // skip number of items (filled in later) resp.serialized.serialized_tx.bytes[r] = 0; r++; int nwitnesses = 2; for (uint32_t i = 0; i < txinput->multisig.signatures_count; i++) { if (txinput->multisig.signatures[i].size == 0) { continue; } nwitnesses++; txinput->multisig.signatures[i].bytes[txinput->multisig.signatures[i].size] = 1; r += tx_serialize_script(txinput->multisig.signatures[i].size + 1, txinput->multisig.signatures[i].bytes, resp.serialized.serialized_tx.bytes + r); } uint32_t script_len = compile_script_multisig(&txinput->multisig, 0); r += ser_length(script_len, resp.serialized.serialized_tx.bytes + r); r += compile_script_multisig(&txinput->multisig, resp.serialized.serialized_tx.bytes + r); resp.serialized.serialized_tx.bytes[0] = nwitnesses; resp.serialized.serialized_tx.size = r; } else { // single signature uint32_t r = 0; r += ser_length(2, resp.serialized.serialized_tx.bytes + r); resp.serialized.signature.bytes[resp.serialized.signature.size] = 1; r += tx_serialize_script(resp.serialized.signature.size + 1, resp.serialized.signature.bytes, resp.serialized.serialized_tx.bytes + r); r += tx_serialize_script(33, node.public_key, resp.serialized.serialized_tx.bytes + r); resp.serialized.serialized_tx.size = r; } } else { // empty witness resp.has_serialized = true; resp.serialized.has_signature_index = false; resp.serialized.has_signature = false; resp.serialized.has_serialized_tx = true; resp.serialized.serialized_tx.bytes[0] = 0; resp.serialized.serialized_tx.size = 1; } // if last witness add tx footer if (idx1 == inputs_count - 1) { uint32_t r = resp.serialized.serialized_tx.size; r += tx_serialize_footer(&to, resp.serialized.serialized_tx.bytes + r); resp.serialized.serialized_tx.size = r; } return true; } #define ENABLE_SEGWIT_NONSEGWIT_MIXING 1 void signing_txack(TransactionType *tx) { if (!signing) { fsm_sendFailure(FailureType_Failure_UnexpectedMessage, _("Not in Signing mode")); layoutHome(); return; } static int update_ctr = 0; if (update_ctr++ == 20) { layoutProgress(_("Signing transaction"), progress); update_ctr = 0; } memset(&resp, 0, sizeof(TxRequest)); switch (signing_stage) { case STAGE_REQUEST_1_INPUT: signing_check_input(&tx->inputs[0]); if (tx->inputs[0].script_type == InputScriptType_SPENDMULTISIG || tx->inputs[0].script_type == InputScriptType_SPENDADDRESS) { memcpy(&input, tx->inputs, sizeof(TxInputType)); #if !ENABLE_SEGWIT_NONSEGWIT_MIXING // don't mix segwit and non-segwit inputs if (idx1 > 0 && to.is_segwit == true) { fsm_sendFailure(FailureType_Failure_DataError, _("Mixing segwit and non-segwit inputs is not allowed")); signing_abort(); return; } #endif if (coin->has_forkid) { if (!tx->inputs[0].has_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("SIGHASH_FORKID input without amount")); signing_abort(); return; } if (to_spend + tx->inputs[0].amount < to_spend) { fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow")); signing_abort(); return; } to_spend += tx->inputs[0].amount; authorized_amount += tx->inputs[0].amount; phase1_request_next_input(); } else { // remember the first non-segwit input -- this is the first input // we need to sign during phase2 if (next_nonsegwit_input == 0xffffffff) next_nonsegwit_input = idx1; send_req_2_prev_meta(); } } else if (tx->inputs[0].script_type == InputScriptType_SPENDWITNESS || tx->inputs[0].script_type == InputScriptType_SPENDP2SHWITNESS) { if (!coin->has_segwit || !coin->segwit) { fsm_sendFailure(FailureType_Failure_DataError, _("Segwit not enabled on this coin")); signing_abort(); return; } // disable native segwit for now if (tx->inputs[0].script_type == InputScriptType_SPENDWITNESS) { fsm_sendFailure(FailureType_Failure_DataError, _("Native segwit is disabled")); signing_abort(); return; } if (!tx->inputs[0].has_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("Segwit input without amount")); signing_abort(); return; } if (to_spend + tx->inputs[0].amount < to_spend) { fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow")); signing_abort(); return; } #if !ENABLE_SEGWIT_NONSEGWIT_MIXING // don't mix segwit and non-segwit inputs if (idx1 == 0) { to.is_segwit = true; } else if (to.is_segwit == false) { fsm_sendFailure(FailureType_Failure_DataError, _("Mixing segwit and non-segwit inputs is not allowed")); signing_abort(); return; } #else to.is_segwit = true; #endif to_spend += tx->inputs[0].amount; authorized_amount += tx->inputs[0].amount; phase1_request_next_input(); } else { fsm_sendFailure(FailureType_Failure_DataError, _("Wrong input script type")); signing_abort(); return; } return; case STAGE_REQUEST_2_PREV_META: tx_init(&tp, tx->inputs_cnt, tx->outputs_cnt, tx->version, tx->lock_time, tx->extra_data_len, false); progress_meta_step = progress_step / (tp.inputs_len + tp.outputs_len); idx2 = 0; if (tp.inputs_len > 0) { send_req_2_prev_input(); } else { tx_serialize_header_hash(&tp); send_req_2_prev_output(); } return; case STAGE_REQUEST_2_PREV_INPUT: progress = (idx1 * progress_step + idx2 * progress_meta_step) >> PROGRESS_PRECISION; if (!tx_serialize_input_hash(&tp, tx->inputs)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize input")); signing_abort(); return; } if (idx2 < tp.inputs_len - 1) { idx2++; send_req_2_prev_input(); } else { idx2 = 0; send_req_2_prev_output(); } return; case STAGE_REQUEST_2_PREV_OUTPUT: progress = (idx1 * progress_step + (tp.inputs_len + idx2) * progress_meta_step) >> PROGRESS_PRECISION; if (!tx_serialize_output_hash(&tp, tx->bin_outputs)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize output")); signing_abort(); return; } if (idx2 == input.prev_index) { if (to_spend + tx->bin_outputs[0].amount < to_spend) { fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow")); signing_abort(); return; } to_spend += tx->bin_outputs[0].amount; } if (idx2 < tp.outputs_len - 1) { /* Check prevtx of next input */ idx2++; send_req_2_prev_output(); } else if (tp.extra_data_len > 0) { // has extra data send_req_2_prev_extradata(0, MIN(1024, tp.extra_data_len)); return; } else { /* prevtx is done */ signing_check_prevtx_hash(); } return; case STAGE_REQUEST_2_PREV_EXTRADATA: if (!tx_serialize_extra_data_hash(&tp, tx->extra_data.bytes, tx->extra_data.size)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize extra data")); signing_abort(); return; } if (tp.extra_data_received < tp.extra_data_len) { // still some data remanining send_req_2_prev_extradata(tp.extra_data_received, MIN(1024, tp.extra_data_len - tp.extra_data_received)); } else { signing_check_prevtx_hash(); } return; case STAGE_REQUEST_3_OUTPUT: if (!signing_check_output(&tx->outputs[0])) { return; } phase1_request_next_output(); return; case STAGE_REQUEST_4_INPUT: progress = 500 + ((signatures * progress_step + idx2 * progress_meta_step) >> PROGRESS_PRECISION); if (idx2 == 0) { tx_init(&ti, inputs_count, outputs_count, version, lock_time, 0, true); sha256_Init(&hashers[0]); } // check prevouts and script type tx_prevout_hash(&hashers[0], tx->inputs); sha256_Update(&hashers[0], &tx->inputs[0].script_type, sizeof(&tx->inputs[0].script_type)); if (idx2 == idx1) { if (!compile_input_script_sig(&tx->inputs[0])) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile input")); signing_abort(); return; } memcpy(&input, &tx->inputs[0], sizeof(input)); memcpy(privkey, node.private_key, 32); memcpy(pubkey, node.public_key, 33); } else { if (next_nonsegwit_input == idx1 && idx2 > idx1 && (tx->inputs[0].script_type == InputScriptType_SPENDADDRESS || tx->inputs[0].script_type == InputScriptType_SPENDMULTISIG)) { next_nonsegwit_input = idx2; } tx->inputs[0].script_sig.size = 0; } if (!tx_serialize_input_hash(&ti, tx->inputs)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize input")); signing_abort(); return; } if (idx2 < inputs_count - 1) { idx2++; send_req_4_input(); } else { uint8_t hash[32]; sha256_Final(&hashers[0], hash); if (memcmp(hash, hash_check, 32) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return; } sha256_Init(&hashers[0]); idx2 = 0; send_req_4_output(); } return; case STAGE_REQUEST_4_OUTPUT: progress = 500 + ((signatures * progress_step + (inputs_count + idx2) * progress_meta_step) >> PROGRESS_PRECISION); if (compile_output(coin, root, tx->outputs, &bin_output, false) <= 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile output")); signing_abort(); return; } // check hashOutputs tx_output_hash(&hashers[0], &bin_output); if (!tx_serialize_output_hash(&ti, &bin_output)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize output")); signing_abort(); return; } if (idx2 < outputs_count - 1) { idx2++; send_req_4_output(); } else { if (!signing_sign_input()) { return; } // since this took a longer time, update progress signatures++; progress = 500 + ((signatures * progress_step) >> PROGRESS_PRECISION); layoutProgress(_("Signing transaction"), progress); update_ctr = 0; if (idx1 < inputs_count - 1) { idx1++; phase2_request_next_input(); } else { idx1 = 0; send_req_5_output(); } } return; case STAGE_REQUEST_SEGWIT_INPUT: resp.has_serialized = true; resp.serialized.has_signature_index = false; resp.serialized.has_signature = false; resp.serialized.has_serialized_tx = true; if (tx->inputs[0].script_type == InputScriptType_SPENDMULTISIG || tx->inputs[0].script_type == InputScriptType_SPENDADDRESS) { if (!coin->has_forkid) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return; } if (!compile_input_script_sig(&tx->inputs[0])) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile input")); signing_abort(); return; } if (tx->inputs[0].amount > authorized_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return; } authorized_amount -= tx->inputs[0].amount; uint8_t hash[32]; signing_hash_bip143(&tx->inputs[0], SIGHASH_ALL | SIGHASH_FORKID, coin->forkid, hash); if (!signing_sign_hash(&tx->inputs[0], node.private_key, node.public_key, hash, SIGHASH_ALL | SIGHASH_FORKID)) return; // since this took a longer time, update progress signatures++; progress = 500 + ((signatures * progress_step) >> PROGRESS_PRECISION); layoutProgress(_("Signing transaction"), progress); update_ctr = 0; } else if (tx->inputs[0].script_type == InputScriptType_SPENDP2SHWITNESS && !tx->inputs[0].has_multisig) { if (!compile_input_script_sig(&tx->inputs[0])) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile input")); signing_abort(); return; } // fixup normal p2pkh script into witness 0 p2wpkh script for p2sh // we convert 76 A9 14 88 AC to 16 00 14 // P2SH input pushes witness 0 script tx->inputs[0].script_sig.size = 0x17; // drops last 2 bytes. tx->inputs[0].script_sig.bytes[0] = 0x16; // push 22 bytes; replaces OP_DUP tx->inputs[0].script_sig.bytes[1] = 0x00; // witness 0 script ; replaces OP_HASH160 // digest is already in right place. } else if (tx->inputs[0].script_type == InputScriptType_SPENDP2SHWITNESS) { // Prepare P2SH witness script. tx->inputs[0].script_sig.size = 0x23; // 35 bytes long: tx->inputs[0].script_sig.bytes[0] = 0x22; // push 34 bytes (full witness script) tx->inputs[0].script_sig.bytes[1] = 0x00; // witness 0 script tx->inputs[0].script_sig.bytes[2] = 0x20; // push 32 bytes (digest) // compute digest of multisig script if (!compile_script_multisig_hash(&tx->inputs[0].multisig, tx->inputs[0].script_sig.bytes + 3)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile input")); signing_abort(); return; } } else { // direct witness scripts require zero scriptSig tx->inputs[0].script_sig.size = 0; } resp.serialized.serialized_tx.size = tx_serialize_input(&to, &tx->inputs[0], resp.serialized.serialized_tx.bytes); if (idx1 < inputs_count - 1) { idx1++; phase2_request_next_input(); } else { idx1 = 0; send_req_5_output(); } return; case STAGE_REQUEST_5_OUTPUT: if (compile_output(coin, root, tx->outputs, &bin_output,false) <= 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile output")); signing_abort(); return; } resp.has_serialized = true; resp.serialized.has_serialized_tx = true; resp.serialized.serialized_tx.size = tx_serialize_output(&to, &bin_output, resp.serialized.serialized_tx.bytes); if (idx1 < outputs_count - 1) { idx1++; send_req_5_output(); } else if (to.is_segwit) { idx1 = 0; send_req_segwit_witness(); } else { send_req_finished(); signing_abort(); } return; case STAGE_REQUEST_SEGWIT_WITNESS: if (!signing_sign_segwit_input(&tx->inputs[0])) { return; } signatures++; progress = 500 + ((signatures * progress_step) >> PROGRESS_PRECISION); layoutProgress(_("Signing transaction"), progress); update_ctr = 0; if (idx1 < inputs_count - 1) { idx1++; send_req_segwit_witness(); } else { send_req_finished(); signing_abort(); } return; } fsm_sendFailure(FailureType_Failure_ProcessError, _("Signing error")); signing_abort(); } void signing_abort(void) { if (signing) { layoutHome(); signing = false; } }