/* * This file is part of the TREZOR project, https://trezor.io/ * * 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 CoinInfo *coin; static const HDNode *root; static CONFIDENTIAL 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, STAGE_REQUEST_DECRED_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 Hasher hashers[3]; static uint8_t CONFIDENTIAL privkey[32]; static uint8_t pubkey[33], sig[64]; static uint8_t hash_prevouts[32], hash_sequence[32],hash_outputs[32]; static uint8_t hash_prefix[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; static uint32_t tx_weight; /* A marker for in_address_n_count to indicate a mismatch in bip32 paths in input */ #define BIP32_NOCHANGEALLOWED 1 /* The number of bip32 levels used in a wallet (chain and address) */ #define BIP32_WALLET_DEPTH 2 /* The chain id used for change */ #define BIP32_CHANGE_CHAIN 1 /* The maximum allowed change address. This should be large enough for normal use and still allow to quickly brute-force the correct bip32 path. */ #define BIP32_MAX_LAST_ELEMENT 1000000 /* transaction header size: 4 byte version */ #define TXSIZE_HEADER 4 /* transaction footer size: 4 byte lock time */ #define TXSIZE_FOOTER 4 /* transaction segwit overhead 2 marker */ #define TXSIZE_SEGWIT_OVERHEAD 2 enum { SIGHASH_ALL = 1, SIGHASH_FORKID = 0x40, }; enum { DECRED_SERIALIZE_FULL = 0, DECRED_SERIALIZE_NO_WITNESS = 1, DECRED_SERIALIZE_WITNESS_SIGNING = 3, }; /* 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 Decred hash_prefix Add I to TransactionChecksum (prevout and type) if (Decred) Return I 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 Decred hash_prefix Add O to TransactionChecksum if (Decred) Return O Display output Ask for confirmation Check tx fee Ask for confirmation Phase2: sign inputs, check that nothing changed =============================================== if (Decred) Skip to STAGE_REQUEST_DECRED_WITNESS 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 Fill scriptsig Remember key for signing 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 Phase3: sign Decred inputs ========================== foreach I (idx1): // input to sign STAGE_REQUEST_DECRED_WITNESS Request I Fill scriptSig Compute hash_witness Sign (hash_type || hash_prefix || hash_witness) 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_decred_witness(void) { signing_stage = STAGE_REQUEST_DECRED_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 hasher_Final(&hashers[0], hash_prevouts); hasher_Final(&hashers[1], hash_sequence); hasher_Final(&hashers[2], hash_check); // init hashOutputs hasher_Reset(&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 == BIP32_NOCHANGEALLOWED) { return; } size_t count = tinput->address_n_count; if (count < BIP32_WALLET_DEPTH) { // no change address allowed in_address_n_count = BIP32_NOCHANGEALLOWED; return; } if (in_address_n_count == 0) { // initialize in_address_n on first input seen in_address_n_count = count; // store the bip32 path up to the account memcpy(in_address_n, tinput->address_n, (count - BIP32_WALLET_DEPTH) * sizeof(uint32_t)); return; } // check that all addresses use a path of same length if (in_address_n_count != count) { in_address_n_count = BIP32_NOCHANGEALLOWED; return; } // check that the bip32 path up to the account matches if (memcmp(in_address_n, tinput->address_n, (count - BIP32_WALLET_DEPTH) * sizeof(uint32_t)) != 0) { // mismatch -> no change address allowed in_address_n_count = BIP32_NOCHANGEALLOWED; return; } } bool check_change_bip32_path(const TxOutputType *toutput) { size_t count = toutput->address_n_count; // Check that the change path has the same bip32 path length, // the same path up to the account, and that the wallet components // (chain id and address) are as expected. // Note: count >= BIP32_WALLET_DEPTH and count == in_address_n_count // imply that in_address_n_count != BIP32_NOCHANGEALLOWED return (count >= BIP32_WALLET_DEPTH && count == in_address_n_count && 0 == memcmp(in_address_n, toutput->address_n, (count - BIP32_WALLET_DEPTH) * sizeof(uint32_t)) && toutput->address_n[count - 2] <= BIP32_CHANGE_CHAIN && toutput->address_n[count - 1] <= BIP32_MAX_LAST_ELEMENT); } bool compile_input_script_sig(TxInputType *tinput) { if (!multisig_fp_mismatch) { // check that this is still multisig uint8_t h[32]; if (!tinput->has_multisig || cryptoMultisigFingerprint(&(tinput->multisig), h) == 0 || memcmp(multisig_fp, h, 32) != 0) { // Transaction has changed during signing return false; } } if (in_address_n_count != BIP32_NOCHANGEALLOWED) { // check that input address didn't change size_t count = tinput->address_n_count; if (count < 2 || count != in_address_n_count || 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(coin, &(tinput->multisig), tinput->script_sig.bytes); } else { // SPENDADDRESS uint8_t hash[20]; ecdsa_get_pubkeyhash(node.public_key, coin->curve->hasher_pubkey, 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(const SignTx *msg, const CoinInfo *_coin, const HDNode *_root) { inputs_count = msg->inputs_count; outputs_count = msg->outputs_count; coin = _coin; root = _root; version = msg->version; lock_time = msg->lock_time; uint32_t size = TXSIZE_HEADER + TXSIZE_FOOTER + ser_length_size(inputs_count) + ser_length_size(outputs_count); if (coin->decred) { size += 4; // Decred expiry size += ser_length_size(inputs_count); // Witness inputs count } tx_weight = 4 * size; 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, coin->curve->hasher_sign); if (coin->decred) { to.version |= (DECRED_SERIALIZE_FULL << 16); to.is_decred = true; to.decred_expiry = msg->decred_expiry; tx_init(&ti, inputs_count, outputs_count, version, lock_time, 0, coin->curve->hasher_sign); ti.version |= (DECRED_SERIALIZE_NO_WITNESS << 16); ti.is_decred = true; ti.decred_expiry = msg->decred_expiry; } // segwit hashes for hashPrevouts and hashSequence hasher_Init(&hashers[0], coin->curve->hasher_sign); hasher_Init(&hashers[1], coin->curve->hasher_sign); hasher_Init(&hashers[2], coin->curve->hasher_sign); 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) { 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); if (coin->decred) { if (txinput->decred_script_version > 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Decred v1+ scripts are not supported")); signing_abort(); return false; } // serialize Decred prefix in Phase 1 resp.has_serialized = true; resp.serialized.has_serialized_tx = true; resp.serialized.serialized_tx.size = tx_serialize_input(&to, txinput, resp.serialized.serialized_tx.bytes); // compute Decred hashPrefix tx_serialize_input_hash(&ti, txinput); } // hash prevout and script type to check it later (relevant for fee computation) tx_prevout_hash(&hashers[2], txinput); hasher_Update(&hashers[2], (const uint8_t *) &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. * this was added during the times segwit was not yet fully activated * to make sure the user is not tricked to use witness change output * instead of regular one therefore creating ANYONECANSPEND output */ 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 { /* We only skip confirmation for the first change output */ is_change = 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; } if (coin->decred) { // serialize Decred prefix in Phase 1 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); // compute Decred hashPrefix tx_serialize_output_hash(&ti, &bin_output); } // compute segwit hashOuts tx_output_hash(&hashers[0], &bin_output, coin->decred); 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; if (fee > ((uint64_t) tx_weight * coin->maxfee_kb)/4000) { layoutFeeOverThreshold(coin, fee); if (!protectButton(ButtonRequestType_ButtonRequest_FeeOverThreshold, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } } // 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 uint32_t signing_hash_type(void) { uint32_t hash_type = SIGHASH_ALL; if (coin->has_forkid) { hash_type |= (coin->forkid << 8) | SIGHASH_FORKID; } return hash_type; } static void phase1_request_next_output(void) { if (idx1 < outputs_count - 1) { idx1++; send_req_3_output(); } else { if (coin->decred) { // compute Decred hashPrefix tx_hash_final(&ti, hash_prefix, false); } hasher_Final(&hashers[0], 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; if (coin->decred) { // Decred prefix serialized in Phase 1, skip Phase 2 send_req_decred_witness(); } else { phase2_request_next_input(); } } } static void signing_hash_bip143(const TxInputType *txinput, uint8_t *hash) { uint32_t hash_type = signing_hash_type(); hasher_Reset(&hashers[0]); hasher_Update(&hashers[0], (const uint8_t *)&version, 4); hasher_Update(&hashers[0], hash_prevouts, 32); hasher_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); hasher_Update(&hashers[0], (const uint8_t*) &txinput->amount, 8); tx_sequence_hash(&hashers[0], txinput); hasher_Update(&hashers[0], hash_outputs, 32); hasher_Update(&hashers[0], (const uint8_t*) &lock_time, 4); hasher_Update(&hashers[0], (const uint8_t*) &hash_type, 4); hasher_Final(&hashers[0], hash); } static void signing_hash_decred(const uint8_t *hash_witness, uint8_t *hash) { uint32_t hash_type = signing_hash_type(); hasher_Reset(&hashers[0]); hasher_Update(&hashers[0], (const uint8_t*) &hash_type, 4); hasher_Update(&hashers[0], hash_prefix, 32); hasher_Update(&hashers[0], hash_witness, 32); hasher_Final(&hashers[0], hash); } static bool signing_sign_hash(TxInputType *txinput, const uint8_t* private_key, const uint8_t *public_key, const uint8_t *hash) { 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(coin->curve->params, 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); uint8_t sighash = signing_hash_type() & 0xff; if (txinput->has_multisig) { // fill in the signature int pubkey_idx = cryptoMultisigPubkeyIndex(coin, &(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(coin, &(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]; hasher_Final(&hashers[0], hash); if (memcmp(hash, hash_outputs, 32) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return false; } uint32_t hash_type = signing_hash_type(); hasher_Update(&ti.hasher, (const uint8_t *)&hash_type, 4); tx_hash_final(&ti, hash, false); resp.has_serialized = true; if (!signing_sign_hash(&input, privkey, pubkey, hash)) 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) { 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, hash); resp.has_serialized = true; if (!signing_sign_hash(txinput, node.private_key, node.public_key, hash)) return false; uint8_t sighash = signing_hash_type() & 0xff; 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] = sighash; 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(coin, &txinput->multisig, 0); r += ser_length(script_len, resp.serialized.serialized_tx.bytes + r); r += compile_script_multisig(coin, &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] = sighash; 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; } static bool signing_sign_decred_input(TxInputType *txinput) { uint8_t hash[32], hash_witness[32]; tx_hash_final(&ti, hash_witness, false); signing_hash_decred(hash_witness, hash); resp.has_serialized = true; if (!signing_sign_hash(txinput, node.private_key, node.public_key, hash)) return false; resp.serialized.serialized_tx.size = tx_serialize_decred_witness(&to, txinput, resp.serialized.serialized_tx.bytes); 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]); tx_weight += tx_input_weight(coin, &tx->inputs[0]); if (coin->decred) { tx_weight += tx_decred_witness_weight(&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->force_bip143) { if (!tx->inputs[0].has_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("BIP 143 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->decred) { fsm_sendFailure(FailureType_Failure_DataError, _("Decred does not support Segwit")); signing_abort(); return; } if (!coin->has_segwit) { fsm_sendFailure(FailureType_Failure_DataError, _("Segwit not enabled on this coin")); 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 (!to.is_segwit) { tx_weight += TXSIZE_SEGWIT_OVERHEAD + to.inputs_len; } #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, coin->curve->hasher_sign); if (coin->decred) { tp.version |= (DECRED_SERIALIZE_NO_WITNESS << 16); tp.is_decred = true; tp.decred_expiry = tx->decred_expiry; } 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; } if (coin->decred && tx->bin_outputs[0].decred_script_version > 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Decred script version does not match previous output")); 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; } tx_weight += tx_output_weight(coin, &tx->outputs[0]); 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, coin->curve->hasher_sign); hasher_Reset(&hashers[0]); } // check prevouts and script type tx_prevout_hash(&hashers[0], tx->inputs); hasher_Update(&hashers[0], (const uint8_t *) &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]; hasher_Final(&hashers[0], hash); if (memcmp(hash, hash_check, 32) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return; } hasher_Reset(&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, coin->decred); 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->force_bip143) { 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], hash); if (!signing_sign_hash(&tx->inputs[0], node.private_key, node.public_key, hash)) 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(coin, &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; case STAGE_REQUEST_DECRED_WITNESS: progress = 500 + ((signatures * progress_step + idx2 * progress_meta_step) >> PROGRESS_PRECISION); if (idx1 == 0) { // witness tx_init(&to, inputs_count, outputs_count, version, lock_time, 0, coin->curve->hasher_sign); to.is_decred = true; } // witness hash tx_init(&ti, inputs_count, outputs_count, version, lock_time, 0, coin->curve->hasher_sign); ti.version |= (DECRED_SERIALIZE_WITNESS_SIGNING << 16); ti.is_decred = true; if (!compile_input_script_sig(&tx->inputs[0])) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile input")); signing_abort(); return; } for (idx2 = 0; idx2 < inputs_count; idx2++) { uint32_t r; if (idx2 == idx1) { r = tx_serialize_decred_witness_hash(&ti, &tx->inputs[0]); } else { r = tx_serialize_decred_witness_hash(&ti, NULL); } if (!r) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize input")); signing_abort(); return; } } if (!signing_sign_decred_input(&tx->inputs[0])) { 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++; send_req_decred_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; } }