/* * 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 "config.h" #include "crypto.h" #include "ecdsa.h" #include "fsm.h" #include "gettext.h" #include "layout2.h" #include "memzero.h" #include "messages.h" #include "messages.pb.h" #include "protect.h" #include "secp256k1.h" #include "transaction.h" #include "zkp_bip340.h" static uint32_t change_count; static const CoinInfo *coin; static AmountUnit amount_unit; static CONFIDENTIAL HDNode root; static CONFIDENTIAL HDNode node; static bool signing = false; enum { STAGE_REQUEST_1_INPUT, STAGE_REQUEST_1_ORIG_META, STAGE_REQUEST_1_ORIG_INPUT, STAGE_REQUEST_2_OUTPUT, STAGE_REQUEST_2_ORIG_OUTPUT, #if !BITCOIN_ONLY STAGE_REQUEST_2_ORIG_EXTRADATA, #endif STAGE_REQUEST_3_INPUT, STAGE_REQUEST_3_PREV_META, STAGE_REQUEST_3_PREV_INPUT, STAGE_REQUEST_3_PREV_OUTPUT, #if !BITCOIN_ONLY STAGE_REQUEST_3_PREV_EXTRADATA, #endif STAGE_REQUEST_3_ORIG_INPUT, STAGE_REQUEST_3_ORIG_OUTPUT, STAGE_REQUEST_3_ORIG_NONLEGACY_INPUT, STAGE_REQUEST_4_INPUT, STAGE_REQUEST_4_OUTPUT, STAGE_REQUEST_NONLEGACY_INPUT, STAGE_REQUEST_5_OUTPUT, STAGE_REQUEST_SEGWIT_WITNESS, #if !BITCOIN_ONLY STAGE_REQUEST_DECRED_WITNESS, #endif } signing_stage; static bool foreign_address_confirmed; // indicates that user approved warning static bool taproot_only; // indicates whether all internal inputs are Taproot static uint32_t idx1; // The index of the input or output in the current tx // which is being processed, signed or serialized. static uint32_t idx2; // The index of the input or output in the original tx // (Phase 1), in the previous tx (Phase 2) or in the // current tx when computing the legacy digest (Phase 2). static uint32_t external_inputs[16]; // bitfield of external input indices static uint32_t signatures; static TxRequest resp; static TxInputType input; static TxOutputType output; static TxOutputBinType bin_output; static TxStruct to; // Used to serialize the current transaction. static TxStruct tp; // Used to compute TXID of original tx in Phase 1 and // previous tx in Phase 2. static TxStruct ti; // Used in Phase 1 to compute original legacy digest or // Decred hashPrefix, and in Phase 2 to compute legacy // digest or Decred witness hash. static Hasher hasher_check; static uint8_t CONFIDENTIAL privkey[32]; static uint8_t pubkey[33]; // Used in Phase 2 to compile scriptSig when signing // legacy inputs. static uint8_t sig[64]; // Used in Phase 1 to store signature of original tx // and in Phase 2 as a temporary signature buffer. #if !BITCOIN_ONLY static uint8_t decred_hash_prefix[32]; #endif static uint64_t total_in, total_out, change_out; static uint64_t orig_total_in, orig_total_out, orig_change_out; static uint32_t progress, progress_step, progress_meta_step; static uint32_t tx_weight; typedef struct { uint32_t inputs_count; uint32_t outputs_count; uint32_t next_legacy_input; uint32_t min_sequence; bool multisig_fp_set; bool multisig_fp_mismatch; uint8_t multisig_fp[32]; uint32_t in_address_n[8]; size_t in_address_n_count; uint32_t version; uint32_t lock_time; uint32_t expiry; uint32_t version_group_id; uint32_t timestamp; #if !BITCOIN_ONLY uint32_t branch_id; uint8_t hash_header[32]; #endif Hasher hasher_check; Hasher hasher_prevouts; Hasher hasher_amounts; Hasher hasher_scriptpubkeys; Hasher hasher_sequences; Hasher hasher_outputs; uint8_t hash_inputs_check[32]; uint8_t hash_prevouts[32]; uint8_t hash_amounts[32]; uint8_t hash_scriptpubkeys[32]; uint8_t hash_sequences[32]; uint8_t hash_outputs[32]; uint8_t hash_prevouts143[32]; uint8_t hash_outputs143[32]; uint8_t hash_sequence143[32]; } TxInfo; static TxInfo info; /* Variables specific to replacement transactions. */ static bool is_replacement; // Is this a replacement transaction? static TxInfo orig_info; static uint8_t orig_hash[32]; // TXID of the original transaction. /* 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 /* The maximum number of change-outputs allowed without user confirmation. */ #define MAX_SILENT_CHANGE_COUNT 2 /* The maximum number of inputs allowed in a transaction is limited by the * number of external inputs that the firmware can count. */ #define MAX_INPUTS_COUNT (sizeof(external_inputs) * 8) /* Setting nSequence to this value for every input in a transaction disables nLockTime. */ #define SEQUENCE_FINAL 0xffffffff /* Setting nSequence to a value greater than this for every input in a transaction disables replace-by-fee opt-in. */ #define MAX_BIP125_RBF_SEQUENCE 0xFFFFFFFD enum { // Signature hash type with the same semantics as SIGHASH_ALL, but instead of // having to include the byte in the signature, it is implied. SIGHASH_ALL_TAPROOT = 0, // Default signature hash type in Bitcoin which signs all inputs and all // outputs of the transaction. SIGHASH_ALL = 1, // Signature hash flag used in some Bitcoin-like altcoins for replay // protection. 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 /* clang-format off Workflow of streamed signing The STAGE_ constants describe the signing_stage when request is sent. I - input O - output Phase1 - process inputs - confirm outputs - check fee and confirm totals - check previous transactions ========================================================= Stage 1: Get inputs and optionally get original inputs. foreach I (idx1): Request I STAGE_REQUEST_1_INPUT Add I to segwit sub-hashes Add I to Decred decred_hash_prefix Add I to TransactionChecksum (prevout and type) if (I has orig_hash) Request input I2 orig_hash, orig_index STAGE_REQUEST_1_ORIG_INPUT Check I matches I2 Add I2 to original segwit sub-hashes Add I2 to orig_info.hash_inputs_check if (Decred) Return I Stage 2: Get outputs and optionally get original outputs. foreach O (idx1): Request O STAGE_REQUEST_2_OUTPUT Add O to Decred decred_hash_prefix Add O to TransactionChecksum if (is_replacement) Request output O2 orig_hash, orig_index STAGE_REQUEST_2_ORIG_OUTPUT Check O matches O2 Add O2 to orig_hash_outputs if (Decred) Return O if (!is_change and !is_replacement) Display output Ask for confirmation Check tx fee Ask for confirmation Stage 3: Check transaction. if (taproot_only) Skip checking of previous transactions. foreach I (idx1): Request I STAGE_REQUEST_3_INPUT Request prevhash I, META STAGE_REQUEST_3_PREV_META foreach prevhash I (idx2): Request prevhash I STAGE_REQUEST_3_PREV_INPUT foreach prevhash O (idx2): Request prevhash O STAGE_REQUEST_3_PREV_OUTPUT Add amount of prevhash O (which is amount of I) Request prevhash extra data (if applicable) STAGE_REQUEST_3_PREV_EXTRADATA Calculate hash of streamed tx, compare to prevhash I if (is_replacement) foreach orig I (idx1): if (orig idx1 is not legacy) Request input I, orig_hash, idx1 STAGE_REQUEST_3_ORIG_NONLEGACY_INPUT Add I to OuterTransactionChecksum Verify signature of I if I is internal else foreach orig I (idx2): Request input I, orig_hash, idx2 STAGE_REQUEST_3_ORIG_INPUT Add I to InnerTransactionChecksum Add I to LegacyTransactionDigest if idx1 == idx2 Add I to OuterTransactionChecksum Save signature for verification Ensure InnerTransactionChecksum matches orig_info.hash_inputs_check foreach orig O (idx2): Request output O, orig_hash, idx2 STAGE_REQUEST_3_ORIG_OUTPUT Add O to InnerTransactionChecksum Add O to LegacyTransactionDigest Ensure InnerTransactionChecksum matches orig_hash_outputs Verify signature of LegacyTransactionDigest Ensure OuterTransactionChecksum matches orig_info.hash_inputs_check Phase2: sign inputs, check that nothing changed =============================================== if (Decred) Skip to STAGE_REQUEST_DECRED_WITNESS foreach I (idx1): // input to sign if (idx1 is not legacy) Request I STAGE_REQUEST_NONLEGACY_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 || decred_hash_prefix || hash_witness) Return witness clang-format on */ static bool add_amount(uint64_t *dest, uint64_t amount) { if (*dest + amount < *dest) { fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow")); signing_abort(); return false; } *dest += amount; return true; } static bool is_rbf_enabled(TxInfo *tx_info) { return tx_info->min_sequence <= MAX_BIP125_RBF_SEQUENCE; } static void set_external_input(uint32_t i) { external_inputs[i / 32] |= (1 << (i % 32)); } static bool is_external_input(uint32_t i) { return external_inputs[i / 32] & (1 << (i % 32)); } static bool has_external_input(void) { uint32_t sum = 0; for (size_t i = 0; i < sizeof(external_inputs) / sizeof(uint32_t); ++i) { sum |= external_inputs[i]; } return sum != 0; } 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_1_orig_meta(void) { signing_stage = STAGE_REQUEST_1_ORIG_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 = sizeof(orig_hash); memcpy(resp.details.tx_hash.bytes, orig_hash, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_1_orig_input(void) { signing_stage = STAGE_REQUEST_1_ORIG_INPUT; resp.has_request_type = true; resp.request_type = RequestType_TXORIGINPUT; 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 = sizeof(orig_hash); memcpy(resp.details.tx_hash.bytes, orig_hash, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_2_output(void) { signing_stage = STAGE_REQUEST_2_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_2_orig_output(void) { signing_stage = STAGE_REQUEST_2_ORIG_OUTPUT; resp.has_request_type = true; resp.request_type = RequestType_TXORIGOUTPUT; 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 = sizeof(orig_hash); memcpy(resp.details.tx_hash.bytes, orig_hash, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } #if !BITCOIN_ONLY void send_req_2_orig_extradata(uint32_t chunk_offset, uint32_t chunk_len) { signing_stage = STAGE_REQUEST_2_ORIG_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 = sizeof(orig_hash); memcpy(resp.details.tx_hash.bytes, orig_hash, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } #endif void send_req_3_input(void) { signing_stage = STAGE_REQUEST_3_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_3_prev_meta(void) { signing_stage = STAGE_REQUEST_3_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_3_prev_input(void) { signing_stage = STAGE_REQUEST_3_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_3_prev_output(void) { signing_stage = STAGE_REQUEST_3_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); } #if !BITCOIN_ONLY void send_req_3_prev_extradata(uint32_t chunk_offset, uint32_t chunk_len) { signing_stage = STAGE_REQUEST_3_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); } #endif void send_req_3_orig_nonlegacy_input(void) { signing_stage = STAGE_REQUEST_3_ORIG_NONLEGACY_INPUT; resp.has_request_type = true; resp.request_type = RequestType_TXORIGINPUT; resp.has_details = true; resp.details.has_request_index = true; resp.details.request_index = idx1; resp.details.has_tx_hash = true; resp.details.tx_hash.size = sizeof(orig_hash); memcpy(resp.details.tx_hash.bytes, orig_hash, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_3_orig_input(void) { signing_stage = STAGE_REQUEST_3_ORIG_INPUT; resp.has_request_type = true; resp.request_type = RequestType_TXORIGINPUT; 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 = sizeof(orig_hash); memcpy(resp.details.tx_hash.bytes, orig_hash, resp.details.tx_hash.size); msg_write(MessageType_MessageType_TxRequest, &resp); } void send_req_3_orig_output(void) { signing_stage = STAGE_REQUEST_3_ORIG_OUTPUT; resp.has_request_type = true; resp.request_type = RequestType_TXORIGOUTPUT; 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 = sizeof(orig_hash); memcpy(resp.details.tx_hash.bytes, orig_hash, resp.details.tx_hash.size); 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_nonlegacy_input(void) { signing_stage = STAGE_REQUEST_NONLEGACY_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); } #if !BITCOIN_ONLY 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); } #endif 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 < info.inputs_count - 1) { idx1++; send_req_1_input(); } else { idx1 = 0; if (is_replacement) { if (idx2 != orig_info.inputs_count) { fsm_sendFailure(FailureType_Failure_DataError, _("Removal of original inputs is not supported.")); signing_abort(); return; } char *description = NULL; if (!is_rbf_enabled(&info) && is_rbf_enabled(&orig_info)) { description = _("Finalize TXID:"); } else { description = _("Update TXID:"); } // Confirm original TXID. layoutConfirmReplacement(description, orig_hash); if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return; } idx2 = 0; } send_req_2_output(); } } void phase1_request_orig_input(void) { if (!is_replacement) { // Get original tx metadata before getting first original input. memcpy(orig_hash, input.orig_hash.bytes, sizeof(orig_hash)); is_replacement = true; idx2 = 0; send_req_1_orig_meta(); } else { if (memcmp(input.orig_hash.bytes, orig_hash, sizeof(orig_hash)) != 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Only one original transaction is allowed.")); signing_abort(); return; } if (input.orig_index >= orig_info.inputs_count) { fsm_sendFailure(FailureType_Failure_DataError, _("Not enough inputs in original transaction.")); signing_abort(); return; } if (idx2 != input.orig_index) { fsm_sendFailure( FailureType_Failure_DataError, _("Rearranging or removal of original inputs is not supported.")); signing_abort(); return; } send_req_1_orig_input(); } } void phase2_request_next_input(void) { if (idx1 == info.next_legacy_input) { idx2 = 0; send_req_4_input(); } else { send_req_nonlegacy_input(); } } void phase2_request_orig_input(void) { if (idx1 < orig_info.inputs_count) { if (idx1 == 0) { // Reset outer transaction check. hasher_Reset(&hasher_check); } if (idx1 == orig_info.next_legacy_input) { idx2 = 0; send_req_3_orig_input(); } else { send_req_3_orig_nonlegacy_input(); } } else { // Ensure that the original transaction inputs haven't changed for the outer // transaction check. uint8_t hash[32]; hasher_Final(&hasher_check, hash); if (memcmp(hash, orig_info.hash_inputs_check, 32) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return; } idx1 = 0; phase2_request_next_input(); } } static bool extract_input_multisig_fp(TxInfo *tx_info, const TxInputType *txinput) { if (txinput->has_multisig && !tx_info->multisig_fp_mismatch) { uint8_t h[32] = {0}; if (cryptoMultisigFingerprint(&txinput->multisig, h) == 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Error computing multisig fingerprint")); signing_abort(); return false; } if (tx_info->multisig_fp_set) { if (memcmp(tx_info->multisig_fp, h, 32) != 0) { tx_info->multisig_fp_mismatch = true; } } else { memcpy(tx_info->multisig_fp, h, 32); tx_info->multisig_fp_set = true; } } else { // single signature tx_info->multisig_fp_mismatch = true; } return true; } bool check_change_multisig_fp(const TxInfo *tx_info, const TxOutputType *txoutput) { uint8_t h[32] = {0}; return tx_info->multisig_fp_set && !tx_info->multisig_fp_mismatch && cryptoMultisigFingerprint(&(txoutput->multisig), h) && memcmp(tx_info->multisig_fp, h, 32) == 0; } void extract_input_bip32_path(TxInfo *tx_info, const TxInputType *tinput) { if (tx_info->in_address_n_count == BIP32_NOCHANGEALLOWED) { return; } size_t count = tinput->address_n_count; if (count < BIP32_WALLET_DEPTH) { // no change address allowed tx_info->in_address_n_count = BIP32_NOCHANGEALLOWED; return; } if (tx_info->in_address_n_count == 0) { // initialize in_address_n on first input seen tx_info->in_address_n_count = count; // store the bip32 path up to the account memcpy(tx_info->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 (tx_info->in_address_n_count != count) { tx_info->in_address_n_count = BIP32_NOCHANGEALLOWED; return; } // check that the bip32 path up to the account matches if (memcmp(tx_info->in_address_n, tinput->address_n, (count - BIP32_WALLET_DEPTH) * sizeof(uint32_t)) != 0) { // mismatch -> no change address allowed tx_info->in_address_n_count = BIP32_NOCHANGEALLOWED; return; } } bool check_change_bip32_path(const TxInfo *tx_info, 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 == tx_info->in_address_n_count && 0 == memcmp(tx_info->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); } static bool fill_input_script_sig(TxInputType *tinput) { if (hdnode_fill_public_key(&node) != 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to derive public key.")); signing_abort(); return false; } if (tinput->has_multisig) { tinput->script_sig.size = compile_script_multisig(coin, &(tinput->multisig), tinput->script_sig.bytes); } else { // SPENDADDRESS uint8_t hash[20] = {0}; 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); } if (tinput->script_sig.size == 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile input.")); signing_abort(); return false; } return true; } static bool derive_node(TxInputType *tinput) { if (!coin_path_check(coin, tinput->script_type, tinput->address_n_count, tinput->address_n, tinput->has_multisig, false) && config_getSafetyCheckLevel() == SafetyCheckLevel_Strict) { fsm_sendFailure(FailureType_Failure_DataError, _("Forbidden key path")); signing_abort(); return false; } // Sanity check not critical for security. The main reason for this is that we // are not comfortable with using the same private key in multiple signature // schemes (ECDSA and Schnorr) and we want to be sure that the user went // through a warning screen before we sign the input. if (!foreign_address_confirmed && !coin_path_check(coin, tinput->script_type, tinput->address_n_count, tinput->address_n, tinput->has_multisig, true)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Transaction has changed during signing")); signing_abort(); return false; } memcpy(&node, &root, sizeof(HDNode)); if (hdnode_private_ckd_cached(&node, tinput->address_n, tinput->address_n_count, NULL) == 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to derive private key.")); signing_abort(); return false; } return true; } static bool tx_info_init(TxInfo *tx_info, uint32_t inputs_count, uint32_t outputs_count, uint32_t version, uint32_t lock_time, bool has_expiry, uint32_t expiry, bool has_branch_id, uint32_t branch_id, bool has_version_group_id, uint32_t version_group_id, bool has_timestamp, uint32_t timestamp) { if (!coin->overwintered) { if (has_version_group_id) { fsm_sendFailure(FailureType_Failure_DataError, _("Version group ID not enabled on this coin.")); signing_abort(); return false; } if (has_branch_id) { fsm_sendFailure(FailureType_Failure_DataError, _("Branch ID not enabled on this coin.")); signing_abort(); return false; } } if (!coin->timestamp && has_timestamp) { fsm_sendFailure(FailureType_Failure_DataError, _("Timestamp not enabled on this coin.")); signing_abort(); return false; } if (!coin->decred && !coin->overwintered && has_expiry) { fsm_sendFailure(FailureType_Failure_DataError, _("Expiry not enabled on this coin.")); signing_abort(); return false; } if (inputs_count + outputs_count < inputs_count) { // Avoid division by zero in progress computations. fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow")); signing_abort(); return false; } tx_info->inputs_count = inputs_count; tx_info->outputs_count = outputs_count; tx_info->next_legacy_input = 0xffffffff; tx_info->min_sequence = SEQUENCE_FINAL; tx_info->multisig_fp_set = false; tx_info->multisig_fp_mismatch = false; tx_info->in_address_n_count = 0; tx_info->version = version; tx_info->lock_time = lock_time; #if BITCOIN_ONLY (void)expiry; (void)version_group_id; (void)timestamp; (void)branch_id; tx_info->expiry = 0; tx_info->version_group_id = 0; tx_info->timestamp = 0; #else tx_info->expiry = (coin->decred || coin->overwintered) ? expiry : 0; if (coin->timestamp) { if (!has_timestamp || !timestamp) { fsm_sendFailure(FailureType_Failure_DataError, _("Timestamp must be set.")); signing_abort(); return false; } tx_info->timestamp = timestamp; } else { tx_info->timestamp = 0; } if (coin->overwintered) { if (!has_version_group_id) { fsm_sendFailure(FailureType_Failure_DataError, _("Version group ID must be set.")); signing_abort(); return false; } if (!has_branch_id) { fsm_sendFailure(FailureType_Failure_DataError, _("Branch ID must be set.")); signing_abort(); return false; } if (tx_info->version != 4 && tx_info->version != 5) { fsm_sendFailure(FailureType_Failure_DataError, _("Unsupported transaction version.")); signing_abort(); return false; } tx_info->version_group_id = version_group_id; tx_info->branch_id = branch_id; } else { tx_info->version_group_id = 0; tx_info->branch_id = 0; } #endif hasher_Init(&tx_info->hasher_check, HASHER_SHA2); #if !BITCOIN_ONLY if (coin->overwintered) { if (tx_info->version == 5) { // ZIP-244 hasher_InitParam(&tx_info->hasher_prevouts, HASHER_BLAKE2B_PERSONAL, "ZTxIdPrevoutHash", 16); hasher_InitParam(&tx_info->hasher_amounts, HASHER_BLAKE2B_PERSONAL, "ZTxTrAmountsHash", 16); hasher_InitParam(&tx_info->hasher_scriptpubkeys, HASHER_BLAKE2B_PERSONAL, "ZTxTrScriptsHash", 16); hasher_InitParam(&tx_info->hasher_sequences, HASHER_BLAKE2B_PERSONAL, "ZTxIdSequencHash", 16); hasher_InitParam(&tx_info->hasher_outputs, HASHER_BLAKE2B_PERSONAL, "ZTxIdOutputsHash", 16); } else { // ZIP-243 hasher_InitParam(&tx_info->hasher_prevouts, HASHER_BLAKE2B_PERSONAL, "ZcashPrevoutHash", 16); hasher_InitParam(&tx_info->hasher_sequences, HASHER_BLAKE2B_PERSONAL, "ZcashSequencHash", 16); hasher_InitParam(&tx_info->hasher_outputs, HASHER_BLAKE2B_PERSONAL, "ZcashOutputsHash", 16); } } else #endif { // BIP-143/BIP-341 hasher_Init(&tx_info->hasher_prevouts, HASHER_SHA2); hasher_Init(&tx_info->hasher_amounts, HASHER_SHA2); hasher_Init(&tx_info->hasher_scriptpubkeys, HASHER_SHA2); hasher_Init(&tx_info->hasher_sequences, HASHER_SHA2); hasher_Init(&tx_info->hasher_outputs, HASHER_SHA2); } return true; } void signing_init(const SignTx *msg, const CoinInfo *_coin, const HDNode *_root) { coin = _coin; amount_unit = msg->has_amount_unit ? msg->amount_unit : AmountUnit_BITCOIN; memcpy(&root, _root, sizeof(HDNode)); if (msg->inputs_count > MAX_INPUTS_COUNT) { fsm_sendFailure(FailureType_Failure_DataError, _("Too many inputs.")); signing_abort(); return; } if (!tx_info_init(&info, msg->inputs_count, msg->outputs_count, msg->version, msg->lock_time, msg->has_expiry, msg->expiry, msg->has_branch_id, msg->branch_id, msg->has_version_group_id, msg->version_group_id, msg->has_timestamp, msg->timestamp)) { return; } uint32_t size = TXSIZE_HEADER + TXSIZE_FOOTER + ser_length_size(info.inputs_count) + ser_length_size(info.outputs_count); #if !BITCOIN_ONLY if (coin->decred) { size += 4; // Decred expiry size += ser_length_size(info.inputs_count); // Witness inputs count } #endif tx_weight = 4 * size; foreign_address_confirmed = false; taproot_only = true; signatures = 0; idx1 = 0; total_in = 0; total_out = 0; change_out = 0; change_count = 0; orig_total_in = 0; orig_total_out = 0; orig_change_out = 0; memzero(external_inputs, sizeof(external_inputs)); memzero(&input, sizeof(TxInputType)); memzero(&output, sizeof(TxOutputType)); memzero(&resp, sizeof(TxRequest)); is_replacement = false; 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) / info.inputs_count; uint32_t branch_id = 0; #if !BITCOIN_ONLY branch_id = info.branch_id; #endif tx_init(&to, info.inputs_count, info.outputs_count, info.version, info.lock_time, info.expiry, branch_id, 0, coin->curve->hasher_sign, coin->overwintered, info.version_group_id, info.timestamp); #if !BITCOIN_ONLY if (coin->decred) { to.version |= (DECRED_SERIALIZE_FULL << 16); to.is_decred = true; tx_init(&ti, info.inputs_count, info.outputs_count, info.version, info.lock_time, info.expiry, branch_id, 0, coin->curve->hasher_sign, coin->overwintered, info.version_group_id, info.timestamp); ti.version |= (DECRED_SERIALIZE_NO_WITNESS << 16); ti.is_decred = true; } #endif hasher_Init(&hasher_check, HASHER_SHA2); layoutProgressSwipe(_("Signing transaction"), 0); send_req_1_input(); } #define MIN(a, b) (((a) < (b)) ? (a) : (b)) static bool is_multisig_input_script_type(const TxInputType *txinput) { // we do not support Multisig with Taproot yet if (txinput->script_type == InputScriptType_SPENDMULTISIG || txinput->script_type == InputScriptType_SPENDP2SHWITNESS || txinput->script_type == InputScriptType_SPENDWITNESS) { return true; } return false; } static bool is_multisig_output_script_type(const TxOutputType *txoutput) { // we do not support Multisig with Taproot yet if (txoutput->script_type == OutputScriptType_PAYTOMULTISIG || txoutput->script_type == OutputScriptType_PAYTOP2SHWITNESS || txoutput->script_type == OutputScriptType_PAYTOWITNESS) { return true; } return false; } static bool is_internal_input_script_type(const TxInputType *txinput) { if (txinput->script_type == InputScriptType_SPENDADDRESS || txinput->script_type == InputScriptType_SPENDMULTISIG || txinput->script_type == InputScriptType_SPENDP2SHWITNESS || txinput->script_type == InputScriptType_SPENDWITNESS || txinput->script_type == InputScriptType_SPENDTAPROOT) { return true; } return false; } static bool is_change_output_script_type(const TxOutputType *txoutput) { if (txoutput->script_type == OutputScriptType_PAYTOADDRESS || txoutput->script_type == OutputScriptType_PAYTOMULTISIG || txoutput->script_type == OutputScriptType_PAYTOP2SHWITNESS || txoutput->script_type == OutputScriptType_PAYTOWITNESS || txoutput->script_type == OutputScriptType_PAYTOTAPROOT) { return true; } return false; } static bool is_segwit_input_script_type(const TxInputType *txinput) { if (txinput->script_type == InputScriptType_SPENDP2SHWITNESS || txinput->script_type == InputScriptType_SPENDWITNESS || txinput->script_type == InputScriptType_SPENDTAPROOT) { return true; } return false; } static bool is_segwit_output_script_type(const TxOutputType *txoutput) { if (txoutput->script_type == OutputScriptType_PAYTOP2SHWITNESS || txoutput->script_type == OutputScriptType_PAYTOWITNESS || txoutput->script_type == OutputScriptType_PAYTOTAPROOT) { return true; } return false; } static bool signing_validate_input(const TxInputType *txinput) { if (txinput->prev_hash.size != 32) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Encountered invalid prevhash")); signing_abort(); return false; } if (txinput->has_multisig && !is_multisig_input_script_type(txinput)) { fsm_sendFailure(FailureType_Failure_DataError, _("Multisig field provided but not expected.")); signing_abort(); return false; } if (is_internal_input_script_type(txinput)) { if (txinput->has_script_pubkey) { // scriptPubKey should only be provided for external inputs fsm_sendFailure(FailureType_Failure_DataError, _("Input's script_pubkey provided but not expected.")); signing_abort(); return false; } } else if (txinput->script_type == InputScriptType_EXTERNAL) { if (txinput->address_n_count != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Input's address_n provided but not expected.")); signing_abort(); return false; } if (!txinput->has_script_pubkey) { // scriptPubKey should be provided for external inputs fsm_sendFailure(FailureType_Failure_DataError, _("Missing script_pubkey field.")); signing_abort(); return false; } } else { fsm_sendFailure(FailureType_Failure_DataError, _("Unsupported script type.")); signing_abort(); return false; } if (is_segwit_input_script_type(txinput)) { if (!coin->has_segwit) { fsm_sendFailure(FailureType_Failure_DataError, _("Segwit not enabled on this coin")); signing_abort(); return false; } } if (txinput->script_type == InputScriptType_SPENDTAPROOT && !coin->has_taproot) { fsm_sendFailure(FailureType_Failure_DataError, _("Taproot not enabled on this coin.")); signing_abort(); return false; } if (txinput->has_orig_hash) { if (!txinput->has_orig_index) { fsm_sendFailure(FailureType_Failure_DataError, _("Missing orig_index field.")); signing_abort(); return false; } if (txinput->orig_hash.size != 32) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Encountered invalid orig_hash")); signing_abort(); return false; } } return true; } static bool signing_validate_output(TxOutputType *txoutput) { if (txoutput->has_multisig && !is_multisig_output_script_type(txoutput)) { fsm_sendFailure(FailureType_Failure_DataError, _("Multisig field provided but not expected.")); signing_abort(); return false; } if (txoutput->address_n_count > 0 && !is_change_output_script_type(txoutput)) { fsm_sendFailure(FailureType_Failure_DataError, _("Output's address_n provided but not expected.")); signing_abort(); return false; } if (txoutput->script_type == OutputScriptType_PAYTOOPRETURN) { if (txoutput->has_address || (txoutput->address_n_count > 0) || txoutput->has_multisig) { fsm_sendFailure(FailureType_Failure_DataError, _("OP_RETURN output with address or multisig")); signing_abort(); return false; } if (txoutput->amount != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("OP_RETURN output with non-zero amount")); signing_abort(); return false; } } else { if (txoutput->has_op_return_data) { fsm_sendFailure( FailureType_Failure_DataError, _("OP RETURN data provided but not OP RETURN script type.")); signing_abort(); return false; } if (txoutput->has_address && txoutput->address_n_count > 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Both address and address_n provided.")); signing_abort(); return false; } else if (!txoutput->has_address && txoutput->address_n_count == 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Missing address")); signing_abort(); return false; } } if (is_segwit_output_script_type(txoutput)) { if (!coin->has_segwit) { fsm_sendFailure(FailureType_Failure_DataError, _("Segwit not enabled on this coin")); signing_abort(); return false; } } if (txoutput->script_type == OutputScriptType_PAYTOTAPROOT && !coin->has_taproot) { fsm_sendFailure(FailureType_Failure_DataError, _("Taproot not enabled on this coin.")); signing_abort(); return false; } if (txoutput->has_orig_hash) { if (!txoutput->has_orig_index) { fsm_sendFailure(FailureType_Failure_DataError, _("Missing orig_index field.")); signing_abort(); return false; } if (txoutput->orig_hash.size != 32) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Encountered invalid orig_hash")); signing_abort(); return false; } } return true; } static bool signing_validate_bin_output(TxOutputBinType *tx_bin_output) { #if !BITCOIN_ONLY if (!coin->decred && tx_bin_output->has_decred_script_version) { fsm_sendFailure( FailureType_Failure_DataError, _("Decred details provided but Decred coin not specified.")); signing_abort(); return false; } #else (void)tx_bin_output; #endif return true; } static bool tx_info_add_input(TxInfo *tx_info, const TxInputType *txinput) { if (txinput->script_type != InputScriptType_EXTERNAL) { // Compute multisig fingerprint for change-output detection. In order for an // output to be considered a change-output, it must have the same // fingerprint as all inputs. if (!extract_input_multisig_fp(tx_info, txinput)) { return false; } // Remember the input's BIP-32 path. Change-outputs must use the same path // as all inputs. extract_input_bip32_path(tx_info, txinput); } // Remember the minimum nSequence value. if (txinput->sequence < tx_info->min_sequence) { tx_info->min_sequence = txinput->sequence; } // Add input to BIP-143 and BIP-341 running sub-hashes. tx_prevout_hash(&tx_info->hasher_prevouts, txinput); tx_amount_hash(&tx_info->hasher_amounts, txinput); tx_script_hash(&tx_info->hasher_scriptpubkeys, txinput->script_pubkey.size, txinput->script_pubkey.bytes); tx_sequence_hash(&tx_info->hasher_sequences, txinput); return true; } static bool tx_info_check_input(TxInfo *tx_info, TxInputType *tinput) { if (!tx_info->multisig_fp_mismatch) { // check that this is still multisig uint8_t h[32] = {0}; if (!tinput->has_multisig || cryptoMultisigFingerprint(&(tinput->multisig), h) == 0 || memcmp(tx_info->multisig_fp, h, 32) != 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Transaction has changed during signing")); signing_abort(); return false; } } if (tx_info->in_address_n_count != BIP32_NOCHANGEALLOWED) { // check that input address didn't change size_t count = tinput->address_n_count; if (count < 2 || count != tx_info->in_address_n_count || 0 != memcmp(tx_info->in_address_n, tinput->address_n, (count - 2) * sizeof(uint32_t))) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Transaction has changed during signing")); signing_abort(); return false; } } return true; } static bool tx_info_add_output(TxInfo *tx_info, const TxOutputBinType *tx_bin_output) { // Add output to BIP-143/BIP-341 hashOutputs. tx_output_hash(&tx_info->hasher_outputs, tx_bin_output, coin->decred); return true; } #if !BITCOIN_ONLY static void txinfo_fill_zip244_header_hash(TxInfo *tx_info) { // `T.1: header_digest` field. // https://zips.z.cash/zip-0244#t-1-header-digest Hasher hasher = {0}; hasher_InitParam(&hasher, HASHER_BLAKE2B_PERSONAL, "ZTxIdHeadersHash", 16); // T.1a: version (4-byte little-endian version identifier including // overwintered flag) uint32_t ver = tx_info->version | TX_OVERWINTERED; hasher_Update(&hasher, (const uint8_t *)&ver, 4); // T.1b: version_group_id (4-byte little-endian version group identifier) hasher_Update(&hasher, (const uint8_t *)&tx_info->version_group_id, 4); // T.1c: consensus_branch_id (4-byte little-endian consensus branch id) hasher_Update(&hasher, (const uint8_t *)&tx_info->branch_id, 4); // T.1d: lock_time (4-byte little-endian nLockTime value) hasher_Update(&hasher, (const uint8_t *)&tx_info->lock_time, 4); // T.1e: expiry_height (4-byte little-endian block height) hasher_Update(&hasher, (const uint8_t *)&tx_info->expiry, 4); hasher_Final(&hasher, tx_info->hash_header); } #endif static void tx_info_finish(TxInfo *tx_info) { hasher_Final(&tx_info->hasher_check, tx_info->hash_inputs_check); hasher_Final(&tx_info->hasher_prevouts, tx_info->hash_prevouts); hasher_Final(&tx_info->hasher_amounts, tx_info->hash_amounts); hasher_Final(&tx_info->hasher_scriptpubkeys, tx_info->hash_scriptpubkeys); hasher_Final(&tx_info->hasher_sequences, tx_info->hash_sequences); hasher_Final(&tx_info->hasher_outputs, tx_info->hash_outputs); if (coin->curve->hasher_sign == HASHER_SHA2D) { hasher_Raw(HASHER_SHA2, tx_info->hash_prevouts, sizeof(tx_info->hash_prevouts), tx_info->hash_prevouts143); hasher_Raw(HASHER_SHA2, tx_info->hash_sequences, sizeof(tx_info->hash_sequences), tx_info->hash_sequence143); hasher_Raw(HASHER_SHA2, tx_info->hash_outputs, sizeof(tx_info->hash_outputs), tx_info->hash_outputs143); } else { memcpy(tx_info->hash_prevouts143, tx_info->hash_prevouts, sizeof(tx_info->hash_prevouts)); memcpy(tx_info->hash_sequence143, tx_info->hash_sequences, sizeof(tx_info->hash_sequences)); memcpy(tx_info->hash_outputs143, tx_info->hash_outputs, sizeof(tx_info->hash_outputs)); } #if !BITCOIN_ONLY if (coin->overwintered && tx_info->version == 5) { txinfo_fill_zip244_header_hash(tx_info); } #endif } static bool tx_info_check_inputs_hash(TxInfo *tx_info) { uint8_t hash[32]; hasher_Final(&tx_info->hasher_check, hash); if (memcmp(hash, tx_info->hash_inputs_check, 32) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return false; } return true; } static bool tx_info_check_outputs_hash(TxInfo *tx_info) { uint8_t hash[32] = {0}; hasher_Final(&tx_info->hasher_check, hash); if (memcmp(hash, tx_info->hash_outputs, 32) != 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Transaction has changed during signing")); signing_abort(); return false; } return true; } static bool signing_add_input(TxInputType *txinput) { // hash all input data to check it later (relevant for fee computation) if (!tx_input_check_hash(&info.hasher_check, txinput)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to hash input")); signing_abort(); return false; } if (txinput->script_type != InputScriptType_EXTERNAL && !coin_path_check(coin, txinput->script_type, txinput->address_n_count, txinput->address_n, txinput->has_multisig, true)) { if (config_getSafetyCheckLevel() == SafetyCheckLevel_Strict && !coin_path_check(coin, txinput->script_type, txinput->address_n_count, txinput->address_n, txinput->has_multisig, false)) { fsm_sendFailure(FailureType_Failure_DataError, _("Forbidden key path")); signing_abort(); return false; } if (!foreign_address_confirmed) { if (!fsm_layoutPathWarning()) { signing_abort(); return false; } foreign_address_confirmed = true; } } if (!fill_input_script_pubkey(coin, &root, txinput)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to derive scriptPubKey")); signing_abort(); return false; } // Add input to BIP-143/BIP-341 computation. if (!tx_info_add_input(&info, txinput)) { return false; } #if !BITCOIN_ONLY 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_input(&to, txinput, resp.serialized.serialized_tx.bytes); // compute Decred hashPrefix tx_serialize_input_hash(&ti, txinput); } #endif return true; } // check if the hash of the prevtx matches static bool signing_check_prevtx_hash(void) { uint8_t hash[32] = {0}; 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; } if (idx1 < info.inputs_count - 1) { idx1++; send_req_3_input(); } else { if (!tx_info_check_inputs_hash(&info)) { return false; } // Everything was checked, now phase 2 begins and the transaction is signed. progress_meta_step = progress_step / (info.inputs_count + info.outputs_count); layoutProgress(_("Signing transaction"), progress); idx1 = 0; #if !BITCOIN_ONLY if (coin->decred) { // Decred prefix serialized in Phase 1, skip Phase 2 send_req_decred_witness(); } else #endif { if (is_replacement) { // Verify original transaction. phase2_request_orig_input(); } else { // Proceed to transaction signing. phase2_request_next_input(); } } } return true; } static bool is_change_output(const TxInfo *tx_info, const TxOutputType *txoutput) { if (!is_change_output_script_type(txoutput)) { return false; } if (txoutput->address_n_count == 0) { return false; } /* * For multisig check that all inputs are multisig */ if (txoutput->has_multisig && !check_change_multisig_fp(tx_info, txoutput)) { return false; } return check_change_bip32_path(tx_info, txoutput); } static bool signing_add_output(TxOutputType *txoutput) { // Phase1: Check outputs // add it to hash_outputs // ask user for permission bool is_change = is_change_output(&info, txoutput); // Don't allow adding new external outputs in replacement transactions. There // is actually nothing wrong with adding new external outputs, but the only // way to pay for them would be by supplying a new (verified) external input, // which is currently not supported. if (is_replacement && !txoutput->has_orig_hash && !is_change) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Adding new external outputs in replacement transactions " "is not supported.")); signing_abort(); return false; } // Add amounts. if (!add_amount(&total_out, txoutput->amount)) { return false; } if (is_change) { if (!add_amount(&change_out, txoutput->amount)) { return false; } change_count++; if (change_count <= 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow")); signing_abort(); return false; } } // Skip confirmation of change-outputs and skip output confirmation altogether // in replacement transactions. bool skip_confirm = is_change || is_replacement; int co = compile_output(coin, amount_unit, &root, txoutput, &bin_output, !skip_confirm); if (!skip_confirm) { 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 !BITCOIN_ONLY 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); } #endif // Add output to BIP-143/BIP-341 computation. return tx_info_add_output(&info, &bin_output); } static bool save_signature(TxInputType *txinput) { // Locate the signature in the witness or script_sig. We are assuming that the // input is not multisig, which simplifies verification. uint8_t *bytes = NULL; size_t size = 0; if (txinput->has_witness && txinput->witness.size > 1) { // Skip the number of stack items. bytes = txinput->witness.bytes + 1; size = txinput->witness.size - 1; } else if (txinput->has_script_sig && txinput->script_sig.size != 0) { bytes = txinput->script_sig.bytes; size = txinput->script_sig.size; } // We make use of the fact that the signature with hash type is at most // 73 bytes in length and that both VarInt <= 252 and OP_PUSH length <= 75 // encode to one byte. if (bytes == NULL || bytes[0] < 1 || bytes[0] > size) { fsm_sendFailure(FailureType_Failure_DataError, _("Unsupported signature script.")); signing_abort(); return false; } size = bytes[0]; bytes += 1; if (txinput->script_type == InputScriptType_SPENDTAPROOT) { if (size != 64) { fsm_sendFailure(FailureType_Failure_DataError, _("Unsupported signature script.")); signing_abort(); return false; } memcpy(sig, bytes, size); } else { // Decode the DER-encoded signature and store in sig. if (bytes[size - 1] != SIGHASH_ALL || ecdsa_sig_from_der(bytes, size - 1, sig) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Unsupported signature script.")); signing_abort(); return false; } } return true; } static bool signing_add_orig_input(TxInputType *orig_input) { // hash all input data to check it later if (!tx_input_check_hash(&orig_info.hasher_check, orig_input)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to hash input")); signing_abort(); return false; } if (!fill_input_script_pubkey(coin, &root, orig_input)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to derive scriptPubKey")); signing_abort(); return false; } // Verify that the original input matches the current input. // An input is characterized by its prev_hash and prev_index. We also // check that the amounts match, so that we don't have to stream the // prevtx twice for the same prevtx output. Verifying that script_type // matches is just a sanity check. When all inputs are taproot, we don't // check the prevtxs, so we have to ensure that the claims about the // script_pubkey values and amounts remain consistent throughout. if (orig_input->prev_hash.size != input.prev_hash.size || memcmp(orig_input->prev_hash.bytes, input.prev_hash.bytes, input.prev_hash.size) != 0 || orig_input->prev_index != input.prev_index || orig_input->amount != input.amount || orig_input->script_type != input.script_type || orig_input->script_pubkey.size != input.script_pubkey.size || memcmp(orig_input->script_pubkey.bytes, input.script_pubkey.bytes, input.script_pubkey.size) != 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Original input does not match current input.")); signing_abort(); return false; } // Add input to original BIP-143/BIP-341 computation. if (!tx_info_add_input(&orig_info, orig_input)) { return false; } if (!add_amount(&orig_total_in, orig_input->amount)) { return false; } // Add input to original TXID computation. if (!tx_serialize_input_hash(&tp, orig_input)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize input")); signing_abort(); return false; } // Remember the first original internal legacy input. if ((orig_input->script_type == InputScriptType_SPENDMULTISIG || orig_input->script_type == InputScriptType_SPENDADDRESS) && !coin->force_bip143 && !coin->overwintered) { if (orig_info.next_legacy_input == 0xffffffff) { orig_info.next_legacy_input = idx2; } } return true; } static bool signing_add_orig_output(TxOutputType *orig_output) { // Compute scriptPubKey. TxOutputBinType orig_bin_output; if (compile_output(coin, amount_unit, &root, orig_output, &orig_bin_output, false) <= 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile output")); signing_abort(); return false; } // Add output to original BIP-143/BIP-341 computation. if (!tx_info_add_output(&orig_info, &orig_bin_output)) { return false; } // Add output to original TXID computation. if (!tx_serialize_output_hash(&tp, &orig_bin_output)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize output")); signing_abort(); return false; } // Add amounts. if (!add_amount(&orig_total_out, orig_output->amount)) { return false; } bool is_change = is_change_output(&orig_info, orig_output); if (is_change) { if (!add_amount(&orig_change_out, orig_output->amount)) { return false; } } if (idx2 != output.orig_index) { // Check a removed original output. // Only removal of change-outputs is allowed. if (!is_change) { fsm_sendFailure( FailureType_Failure_DataError, _("Removal of original external outputs is not supported.")); signing_abort(); return false; } } else { // Check the original output which corresponds to the current output. // The scriptPubkeys must come out the same for original and current. if (bin_output.script_pubkey.size != orig_bin_output.script_pubkey.size || memcmp(bin_output.script_pubkey.bytes, orig_bin_output.script_pubkey.bytes, bin_output.script_pubkey.size) != 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Not an original output.")); signing_abort(); return false; } // If the current output is a change-output, then the original output must // also be a change-output. if (is_change_output(&info, &output) && !is_change) { fsm_sendFailure( FailureType_Failure_DataError, _("Original output is missing change-output parameters.")); signing_abort(); return false; } if (!is_change) { if (output.amount < orig_output->amount) { // Replacement transactions may need to decrease the value of external // outputs to bump the fee. This is needed if the original transaction // transfers the entire account balance ("Send Max"). for (int page = 0; page < 2; ++page) { layoutConfirmModifyOutput(coin, amount_unit, &output, orig_output, page); if (!protectButton(ButtonRequestType_ButtonRequest_ConfirmOutput, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } } } else if (output.amount > orig_output->amount) { // Only PayJoin transactions may increase the value of external outputs // by supplying a verified external input. However, verified external // inputs are currently not supported. fsm_sendFailure( FailureType_Failure_ProcessError, _("Increasing original output amounts is not supported.")); signing_abort(); return false; } } } return true; } static bool signing_confirm_tx(void) { if (has_external_input()) { layoutConfirmUnverifiedExternalInputs(); if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } } if (coin->negative_fee) { // bypass check for negative fee coins, required for reward TX } else { // check fees if (total_out > total_in) { fsm_sendFailure(FailureType_Failure_NotEnoughFunds, _("Not enough funds")); signing_abort(); return false; } } uint64_t fee = 0; if (total_out <= total_in) { fee = total_in - total_out; if (fee > ((uint64_t)tx_weight * coin->maxfee_kb) / 4000) { layoutFeeOverThreshold(coin, amount_unit, fee); if (!protectButton(ButtonRequestType_ButtonRequest_FeeOverThreshold, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } } } else { fee = 0; } if (change_count > MAX_SILENT_CHANGE_COUNT) { layoutChangeCountOverThreshold(change_count); if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } } if (is_replacement) { // Replacement transaction. // Reject negative fees in original or replacement transactions, so that we // don't have to deal with the UI implications. if (total_out > total_in || orig_total_out > orig_total_in) { fsm_sendFailure( FailureType_Failure_ProcessError, _("Negative fees not supported in transaction replacement.")); signing_abort(); return false; } uint64_t orig_fee = orig_total_in - orig_total_out; // Sanity check. Replacement transactions are only allowed to make // amendments which do not increase the amount that we are spending on // external outputs. Additional funds can only go towards the fee, which is // confirmed by the user. The check may fail if the replacement transaction // starts mixing accounts and breaks change-output identification. if (total_out - change_out > orig_total_out - orig_change_out) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Invalid replacement transaction.")); signing_abort(); return false; } // Replacement transactions must not change the effective nLockTime. uint32_t effective_lock_time = info.min_sequence == SEQUENCE_FINAL ? 0 : info.lock_time; uint32_t orig_effective_lock_time = orig_info.min_sequence == SEQUENCE_FINAL ? 0 : orig_info.lock_time; if (effective_lock_time != orig_effective_lock_time) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Original transactions must have same effective " "nLockTime as replacement transaction.")); signing_abort(); return false; } // Fee modification. if (fee != orig_fee) { layoutConfirmModifyFee(coin, amount_unit, orig_fee, fee); if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } } } else { // Standard transaction. if (info.lock_time != 0) { bool lock_time_disabled = (info.min_sequence == SEQUENCE_FINAL); layoutConfirmNondefaultLockTime(info.lock_time, lock_time_disabled); if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } } // last confirmation layoutConfirmTx(coin, amount_unit, total_in, total_out, change_out, tx_weight); if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) { fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL); signing_abort(); return false; } } return true; } static uint32_t signing_hash_type(const TxInputType *txinput) { uint32_t hash_type = SIGHASH_ALL; if (txinput->script_type == InputScriptType_SPENDTAPROOT) { hash_type = SIGHASH_ALL_TAPROOT; } if (coin->has_fork_id) { hash_type |= (coin->fork_id << 8) | SIGHASH_FORKID; } return hash_type; } static void signing_hash_bip143(const TxInfo *tx_info, const TxInputType *txinput, uint8_t *hash) { uint32_t hash_type = signing_hash_type(txinput); Hasher hasher_preimage = {0}; hasher_Init(&hasher_preimage, coin->curve->hasher_sign); // nVersion hasher_Update(&hasher_preimage, (const uint8_t *)&tx_info->version, 4); // hashPrevouts hasher_Update(&hasher_preimage, tx_info->hash_prevouts143, 32); // hashSequence hasher_Update(&hasher_preimage, tx_info->hash_sequence143, 32); // outpoint tx_prevout_hash(&hasher_preimage, txinput); // scriptCode tx_script_hash(&hasher_preimage, txinput->script_sig.size, txinput->script_sig.bytes); // amount hasher_Update(&hasher_preimage, (const uint8_t *)&txinput->amount, 8); // nSequence tx_sequence_hash(&hasher_preimage, txinput); // hashOutputs hasher_Update(&hasher_preimage, tx_info->hash_outputs143, 32); // nLockTime hasher_Update(&hasher_preimage, (const uint8_t *)&tx_info->lock_time, 4); // nHashType hasher_Update(&hasher_preimage, (const uint8_t *)&hash_type, 4); hasher_Final(&hasher_preimage, hash); } static void signing_hash_bip341(const TxInfo *tx_info, uint32_t i, uint8_t sighash_type, uint8_t *hash) { const uint8_t zero = 0; Hasher sigmsg_hasher = {0}; hasher_Init(&sigmsg_hasher, HASHER_SHA2_TAPSIGHASH); // sighash epoch 0 hasher_Update(&sigmsg_hasher, &zero, 1); // nHashType hasher_Update(&sigmsg_hasher, &sighash_type, 1); // nVersion hasher_Update(&sigmsg_hasher, (const uint8_t *)&tx_info->version, 4); // nLockTime hasher_Update(&sigmsg_hasher, (const uint8_t *)&tx_info->lock_time, 4); // sha_prevouts hasher_Update(&sigmsg_hasher, tx_info->hash_prevouts, 32); // sha_amounts hasher_Update(&sigmsg_hasher, tx_info->hash_amounts, 32); // sha_scriptpubkeys hasher_Update(&sigmsg_hasher, tx_info->hash_scriptpubkeys, 32); // sha_sequences hasher_Update(&sigmsg_hasher, tx_info->hash_sequences, 32); // sha_outputs hasher_Update(&sigmsg_hasher, tx_info->hash_outputs, 32); // spend_type 0 (no tapscript message extension, no annex) hasher_Update(&sigmsg_hasher, &zero, 1); // input_index hasher_Update(&sigmsg_hasher, (const uint8_t *)&i, 4); hasher_Final(&sigmsg_hasher, hash); } #if !BITCOIN_ONLY static void signing_hash_zip243(const TxInfo *tx_info, const TxInputType *txinput, uint8_t *hash) { uint32_t hash_type = signing_hash_type(txinput); const uint8_t null_bytes[32] = {0}; uint8_t personal[16] = {0}; memcpy(personal, "ZcashSigHash", 12); memcpy(personal + 12, &tx_info->branch_id, 4); Hasher hasher_preimage = {0}; hasher_InitParam(&hasher_preimage, HASHER_BLAKE2B_PERSONAL, personal, sizeof(personal)); // 1. nVersion | fOverwintered uint32_t ver = tx_info->version | TX_OVERWINTERED; hasher_Update(&hasher_preimage, (const uint8_t *)&ver, 4); // 2. nVersionGroupId hasher_Update(&hasher_preimage, (const uint8_t *)&tx_info->version_group_id, 4); // 3. hashPrevouts hasher_Update(&hasher_preimage, tx_info->hash_prevouts, 32); // 4. hashSequence hasher_Update(&hasher_preimage, tx_info->hash_sequences, 32); // 5. hashOutputs hasher_Update(&hasher_preimage, tx_info->hash_outputs, 32); // 6. hashJoinSplits hasher_Update(&hasher_preimage, null_bytes, 32); // 7. hashShieldedSpends hasher_Update(&hasher_preimage, null_bytes, 32); // 8. hashShieldedOutputs hasher_Update(&hasher_preimage, null_bytes, 32); // 9. nLockTime hasher_Update(&hasher_preimage, (const uint8_t *)&tx_info->lock_time, 4); // 10. expiryHeight hasher_Update(&hasher_preimage, (const uint8_t *)&tx_info->expiry, 4); // 11. valueBalance hasher_Update(&hasher_preimage, null_bytes, 8); // 12. nHashType hasher_Update(&hasher_preimage, (const uint8_t *)&hash_type, 4); // 13a. outpoint tx_prevout_hash(&hasher_preimage, txinput); // 13b. scriptCode tx_script_hash(&hasher_preimage, txinput->script_sig.size, txinput->script_sig.bytes); // 13c. value hasher_Update(&hasher_preimage, (const uint8_t *)&txinput->amount, 8); // 13d. nSequence tx_sequence_hash(&hasher_preimage, txinput); hasher_Final(&hasher_preimage, hash); } #endif #if !BITCOIN_ONLY static void signing_hash_zip244(const TxInfo *tx_info, const TxInputType *txinput, uint8_t *hash) { Hasher hasher = {0}; // `S.2g: txin_sig_digest` field for signature digest computation. // https://zips.z.cash/zip-0244#s-2g-txin-sig-digest uint8_t txin_sig_digest[32] = {0}; hasher_InitParam(&hasher, HASHER_BLAKE2B_PERSONAL, "Zcash___TxInHash", 16); // S.2g.i: prevout (field encoding) tx_prevout_hash(&hasher, txinput); // S.2g.ii: value (8-byte signed little-endian) hasher_Update(&hasher, (const uint8_t *)&txinput->amount, 8); // S.2g.iii: scriptPubKey (field encoding) tx_script_hash(&hasher, txinput->script_pubkey.size, txinput->script_pubkey.bytes); // S.2g.iv: nSequence (4-byte unsigned little-endian) hasher_Update(&hasher, (const uint8_t *)&txinput->sequence, 4); hasher_Final(&hasher, txin_sig_digest); // `S.2: transparent_sig_digest` field for signature digest computation. // https://zips.z.cash/zip-0244#s-2-transparent-sig-digest uint8_t transparent_sig_digest[32] = {0}; hasher_InitParam(&hasher, HASHER_BLAKE2B_PERSONAL, "ZTxIdTranspaHash", 16); uint32_t hash_type = signing_hash_type(txinput); // S.2a: hash_type (1 byte) hasher_Update(&hasher, (const uint8_t *)&hash_type, 1); // S.2b: prevouts_sig_digest (32-byte hash) hasher_Update(&hasher, tx_info->hash_prevouts, sizeof(tx_info->hash_prevouts)); // S.2c: amounts_sig_digest (32-byte hash) hasher_Update(&hasher, tx_info->hash_amounts, sizeof(tx_info->hash_amounts)); // S.2d: scriptpubkeys_sig_digest (32-byte hash) hasher_Update(&hasher, tx_info->hash_scriptpubkeys, sizeof(tx_info->hash_scriptpubkeys)); // S.2e: sequence_sig_digest (32-byte hash) hasher_Update(&hasher, tx_info->hash_sequences, sizeof(tx_info->hash_sequences)); // S.2f: outputs_sig_digest (32-byte hash) hasher_Update(&hasher, tx_info->hash_outputs, sizeof(tx_info->hash_outputs)); // S.2g: txin_sig_digest (32-byte hash) hasher_Update(&hasher, txin_sig_digest, sizeof(txin_sig_digest)); hasher_Final(&hasher, transparent_sig_digest); // `S.3: sapling_digest` field. Empty Sapling bundle. uint8_t sapling_digest[32] = {0}; hasher_InitParam(&hasher, HASHER_BLAKE2B_PERSONAL, "ZTxIdSaplingHash", 16); hasher_Final(&hasher, sapling_digest); // `S.4: orchard_digest` field. Empty Orchard bundle. uint8_t orchard_digest[32] = {0}; hasher_InitParam(&hasher, HASHER_BLAKE2B_PERSONAL, "ZTxIdOrchardHash", 16); hasher_Final(&hasher, orchard_digest); // Final transaction signature digest. // https://zips.z.cash/zip-0244#id13 uint8_t personal[16] = {0}; memcpy(personal, "ZcashTxHash_", 12); memcpy(personal + 12, &tx_info->branch_id, 4); hasher_InitParam(&hasher, HASHER_BLAKE2B_PERSONAL, personal, sizeof(personal)); // S.1: header_digest (32-byte hash output) hasher_Update(&hasher, tx_info->hash_header, sizeof(tx_info->hash_header)); // S.2: transparent_sig_digest (32-byte hash output) hasher_Update(&hasher, transparent_sig_digest, sizeof(transparent_sig_digest)); // S.3: sapling_digest (32-byte hash output) hasher_Update(&hasher, sapling_digest, sizeof(sapling_digest)); // S.4: orchard_digest (32-byte hash output) hasher_Update(&hasher, orchard_digest, sizeof(orchard_digest)); hasher_Final(&hasher, hash); } #endif static bool signing_verify_orig_nonlegacy_input(TxInputType *orig_input) { // Nothing to verify for external inputs. if (orig_input->script_type == InputScriptType_EXTERNAL) { return true; } // Save the signature before script_sig is overwritten. if (!save_signature(orig_input)) { return false; } // Derive node.public_key and fill script_sig with the legacy scriptPubKey // (aka BIP-143 script code), which is what our code expects here in order // to properly compute the BIP-143 transaction digest. if (!derive_node(orig_input) || !fill_input_script_sig(orig_input)) { return false; } // Compute the signed digest and verify signature. uint8_t hash[32] = {0}; uint32_t hash_type = signing_hash_type(orig_input); bool valid = false; if (orig_input->script_type == InputScriptType_SPENDTAPROOT) { signing_hash_bip341(&orig_info, idx1, hash_type & 0xff, hash); uint8_t output_public_key[32] = {0}; valid = (zkp_bip340_tweak_public_key(node.public_key + 1, NULL, output_public_key) == 0) && (zkp_bip340_verify_digest(output_public_key, sig, hash) == 0); } else { #if !BITCOIN_ONLY if (coin->overwintered) { signing_hash_zip243(&orig_info, orig_input, hash); } else #endif { signing_hash_bip143(&orig_info, orig_input, hash); } valid = ecdsa_verify_digest(coin->curve->params, node.public_key, sig, hash) == 0; } if (!valid) { fsm_sendFailure(FailureType_Failure_DataError, _("Invalid signature.")); signing_abort(); } return valid; } static bool signing_verify_orig_legacy_input(void) { // Finalize legacy digest computation. uint32_t hash_type = signing_hash_type(&input); hasher_Update(&ti.hasher, (const uint8_t *)&hash_type, 4); // Compute the signed digest and verify signature. uint8_t hash[32] = {0}; tx_hash_final(&ti, hash, false); bool valid = ecdsa_verify_digest(coin->curve->params, node.public_key, sig, hash) == 0; if (!valid) { fsm_sendFailure(FailureType_Failure_DataError, _("Invalid signature.")); signing_abort(); } return valid; } static bool signing_hash_orig_input(TxInputType *orig_input) { if (idx2 == 0) { uint32_t branch_id = 0; #if !BITCOIN_ONLY branch_id = orig_info.branch_id; #endif tx_init(&ti, orig_info.inputs_count, orig_info.outputs_count, orig_info.version, orig_info.lock_time, orig_info.expiry, branch_id, 0, coin->curve->hasher_sign, coin->overwintered, orig_info.version_group_id, orig_info.timestamp); // Reset the inner transaction check. hasher_Reset(&orig_info.hasher_check); } // Add input to the inner transaction check. if (!tx_input_check_hash(&orig_info.hasher_check, orig_input)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to hash input")); signing_abort(); return false; } if (idx2 == idx1) { // Add input to the outer transaction check. if (!tx_input_check_hash(&hasher_check, orig_input)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to hash input")); signing_abort(); return false; } // Save the signature before script_sig is overwritten. if (!save_signature(orig_input)) { return false; } // Derive node.public_key and fill script_sig with the legacy // scriptPubKey which is what our code expects here in order to properly // compute the transaction digest. if (!derive_node(orig_input) || !fill_input_script_sig(orig_input)) { return false; } memcpy(&input, orig_input, sizeof(input)); } else { if (orig_info.next_legacy_input == idx1 && idx2 > idx1 && (orig_input->script_type == InputScriptType_SPENDADDRESS || orig_input->script_type == InputScriptType_SPENDMULTISIG)) { orig_info.next_legacy_input = idx2; } orig_input->script_sig.size = 0; } // Add input to original legacy digest computation now that script_sig is // set. if (!tx_serialize_input_hash(&ti, orig_input)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize input")); signing_abort(); return false; } return true; } static bool signing_hash_orig_output(TxOutputType *orig_output) { if (compile_output(coin, amount_unit, &root, orig_output, &bin_output, false) <= 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile output")); signing_abort(); return false; } // Add the output to the inner transaction check. tx_output_hash(&orig_info.hasher_check, &bin_output, coin->decred); // Add the output to original legacy digest computation if (!tx_serialize_output_hash(&ti, &bin_output)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to serialize output")); signing_abort(); return false; } return true; } static bool signing_check_orig_tx(void) { uint8_t hash[32] = {0}; // Finalize original TXID computation and ensure it matches orig_hash. tx_hash_final(&tp, hash, true); if (memcmp(hash, orig_hash, sizeof(orig_hash)) != 0) { // This may happen if incorrect information is supplied in the TXORIGINPUT // or TXORIGOUTPUT responses or if the device is loaded with the wrong seed, // because we derive the scriptPubKeys of change-outputs from the seed using // the provided path. fsm_sendFailure(FailureType_Failure_ProcessError, _("Invalid original TXID.")); signing_abort(); return false; } return true; } static void phase1_finish(void) { #if !BITCOIN_ONLY if (coin->decred) { // compute Decred hashPrefix tx_hash_final(&ti, decred_hash_prefix, false); } #endif // Finish computation of BIP-143/BIP-341/ZIP-243 sub-hashes. tx_info_finish(&info); tx_info_finish(&orig_info); if (is_replacement) { if (!signing_check_orig_tx()) { return; } } if (!signing_confirm_tx()) { return; } if (taproot_only) { // All internal inputs are Taproot. We do not need to verify that their // parameters match previous transactions. We can trust the amounts and // scriptPubKeys, because if an invalid value is provided then all issued // signatures will be invalid. if (is_replacement) { // Verify original transaction. phase2_request_orig_input(); } else { // Proceed directly to transaction signing. phase2_request_next_input(); } #if !BITCOIN_ONLY } else if (coin->overwintered && info.version == 5) { // ZIP-244 transactions are treated same as Taproot. phase2_request_next_input(); #endif } else { // There are internal non-Taproot inputs. We need to verify all inputs, // because we can't trust any amounts or scriptPubKeys. If we did, then an // attacker who provides invalid information about amounts, scriptPubKeys // and/or script types may still obtain valid signatures for legacy and // SegWit v0 inputs. These valid signatures could be exploited in subsequent // signing operations to falsely claim externality of the already signed // inputs or to falsely claim that a transaction is a replacement of an // already approved transaction or to construct a valid transaction by // combining signatures obtained in multiple rounds of the attack. send_req_3_input(); } } static void phase1_request_next_output(void) { if (idx1 < info.outputs_count - 1) { idx1++; send_req_2_output(); } else { idx1 = 0; if (is_replacement) { if (idx2 < orig_info.outputs_count) { send_req_2_orig_output(); #if !BITCOIN_ONLY } else if (coin->extra_data && tp.extra_data_len > 0) { // has extra data send_req_2_orig_extradata(0, MIN(1024, tp.extra_data_len)); #endif } else { phase1_finish(); } } else { phase1_finish(); } } } static void phase1_request_orig_output(void) { if (!is_replacement || memcmp(output.orig_hash.bytes, orig_hash, sizeof(orig_hash)) != 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Unknown original transaction.")); signing_abort(); return; } if (output.orig_index >= orig_info.outputs_count) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Not enough outputs in original transaction.")); signing_abort(); return; } if (idx2 > output.orig_index) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Rearranging of original outputs is not supported.")); signing_abort(); return; } send_req_2_orig_output(); } #if !BITCOIN_ONLY static void signing_hash_decred(const TxInputType *txinput, const uint8_t *hash_witness, uint8_t *hash) { uint32_t hash_type = signing_hash_type(txinput); Hasher hasher_preimage = {0}; hasher_Init(&hasher_preimage, coin->curve->hasher_sign); hasher_Update(&hasher_preimage, (const uint8_t *)&hash_type, 4); hasher_Update(&hasher_preimage, decred_hash_prefix, 32); hasher_Update(&hasher_preimage, hash_witness, 32); hasher_Final(&hasher_preimage, hash); } #endif static bool signing_sign_ecdsa(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(txinput) & 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_bip340(const uint8_t *private_key, const uint8_t *hash) { resp.has_serialized = true; resp.serialized.has_signature_index = true; resp.serialized.signature_index = idx1; resp.serialized.has_signature = true; resp.serialized.has_serialized_tx = true; resp.serialized.signature.size = 64; uint8_t output_private_key[32] = {0}; bool ret = (zkp_bip340_tweak_private_key(private_key, NULL, output_private_key) == 0); ret = ret && (zkp_bip340_sign_digest(output_private_key, hash, resp.serialized.signature.bytes, NULL) == 0); memzero(output_private_key, sizeof(output_private_key)); if (!ret) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Signing failed")); signing_abort(); } return ret; } static bool signing_sign_legacy_input(void) { // Finalize legacy digest computation. uint32_t hash_type = signing_hash_type(&input); hasher_Update(&ti.hasher, (const uint8_t *)&hash_type, 4); // Compute the digest and generate signature. uint8_t hash[32] = {0}; tx_hash_final(&ti, hash, false); resp.has_serialized = true; if (!signing_sign_ecdsa(&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] = {0}; if (is_external_input(idx1) != (txinput->script_type == InputScriptType_EXTERNAL)) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return false; } if (txinput->script_type == InputScriptType_SPENDTAPROOT) { signing_hash_bip341(&info, idx1, signing_hash_type(txinput), hash); if (!tx_info_check_input(&info, txinput) || !derive_node(txinput) || !signing_sign_bip340(node.private_key, hash)) { return false; } uint32_t r = 0; // write witness (number of stack items followed by signature) r += ser_length(1, resp.serialized.serialized_tx.bytes + r); r += tx_serialize_script(resp.serialized.signature.size, resp.serialized.signature.bytes, resp.serialized.serialized_tx.bytes + r); resp.serialized.serialized_tx.size = r; } else if (txinput->script_type == InputScriptType_SPENDP2SHWITNESS || txinput->script_type == InputScriptType_SPENDWITNESS) { if (!txinput->has_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("Segwit input without amount")); signing_abort(); return false; } if (taproot_only) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Transaction has changed during signing")); signing_abort(); return false; } if (!tx_info_check_input(&info, txinput) || !derive_node(txinput) || !fill_input_script_sig(txinput)) { return false; } signing_hash_bip143(&info, txinput, hash); resp.has_serialized = true; if (!signing_sign_ecdsa(txinput, node.private_key, node.public_key, hash)) return false; uint8_t sighash = signing_hash_type(txinput) & 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 { // no signature to be generated resp.has_serialized = true; resp.serialized.has_signature_index = false; resp.serialized.has_signature = false; resp.serialized.has_serialized_tx = true; if (txinput->script_type == InputScriptType_EXTERNAL && txinput->has_witness) { // fill in the provided witness memcpy(resp.serialized.serialized_tx.bytes, txinput->witness.bytes, txinput->witness.size); resp.serialized.serialized_tx.size = txinput->witness.size; } else { // empty witness resp.serialized.serialized_tx.bytes[0] = 0; resp.serialized.serialized_tx.size = 1; } } // if last witness add tx footer if (idx1 == info.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; } #if !BITCOIN_ONLY 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(txinput, hash_witness, hash); resp.has_serialized = true; if (!signing_sign_ecdsa(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; } #endif #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; } memzero(&resp, sizeof(TxRequest)); switch (signing_stage) { case STAGE_REQUEST_1_INPUT: if (!signing_validate_input(&tx->inputs[0]) || !signing_add_input(&tx->inputs[0])) { return; } if (!tx->inputs[0].has_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("Expected input with amount")); signing_abort(); return; } if (!add_amount(&total_in, tx->inputs[0].amount)) { return; } tx_weight += tx_input_weight(coin, &tx->inputs[0]); #if !BITCOIN_ONLY if (coin->decred) { tx_weight += tx_decred_witness_weight(&tx->inputs[0]); } #endif if (tx->inputs[0].script_type != InputScriptType_SPENDTAPROOT && tx->inputs[0].script_type != InputScriptType_EXTERNAL) { taproot_only = false; } if (tx->inputs[0].script_type == InputScriptType_SPENDMULTISIG || tx->inputs[0].script_type == InputScriptType_SPENDADDRESS) { #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 && !coin->overwintered) { // remember the first non-segwit input -- this is the first input // we need to sign during phase2 if (info.next_legacy_input == 0xffffffff) { info.next_legacy_input = idx1; } } } else if (is_segwit_input_script_type(&tx->inputs[0])) { 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 } else if (tx->inputs[0].script_type == InputScriptType_EXTERNAL) { if (config_getSafetyCheckLevel() == SafetyCheckLevel_Strict) { fsm_sendFailure(FailureType_Failure_ProcessError, _("External inputs not allowed.")); signing_abort(); return; } set_external_input(idx1); } else { fsm_sendFailure(FailureType_Failure_DataError, _("Wrong input script type")); signing_abort(); return; } if (tx->inputs[0].has_orig_hash) { #if !BITCOIN_ONLY if (coin->overwintered && info.version != 4) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Replacement transactions are not supported.")); signing_abort(); return; } #endif memcpy(&input, &tx->inputs[0], sizeof(input)); phase1_request_orig_input(); } else { phase1_request_next_input(); } return; case STAGE_REQUEST_1_ORIG_META: if (!tx_info_init(&orig_info, tx->inputs_cnt, tx->outputs_cnt, tx->version, tx->lock_time, tx->has_expiry, tx->expiry, tx->has_branch_id, tx->branch_id, tx->has_version_group_id, tx->version_group_id, tx->has_timestamp, tx->timestamp)) { return; } if (coin->decred) { fsm_sendFailure(FailureType_Failure_DataError, _("Replacement transactions not supported")); signing_abort(); return; } if (!coin->extra_data && tx->extra_data_len > 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Extra data not enabled on this coin.")); signing_abort(); return; } // Initialize computation of original TXID. tx_init(&tp, tx->inputs_cnt, tx->outputs_cnt, tx->version, tx->lock_time, tx->expiry, tx->branch_id, tx->extra_data_len, coin->curve->hasher_sign, coin->overwintered, tx->version_group_id, tx->timestamp); phase1_request_orig_input(); return; case STAGE_REQUEST_1_ORIG_INPUT: if (!signing_validate_input(tx->inputs) || !signing_add_orig_input(tx->inputs)) { return; } idx2++; phase1_request_next_input(); return; case STAGE_REQUEST_2_OUTPUT: if (!signing_validate_output(&tx->outputs[0]) || !signing_add_output(&tx->outputs[0])) { return; } tx_weight += tx_output_weight(coin, &tx->outputs[0]); if (tx->outputs[0].has_orig_hash) { memcpy(&output, &tx->outputs[0], sizeof(output)); phase1_request_orig_output(); } else { phase1_request_next_output(); } return; case STAGE_REQUEST_2_ORIG_OUTPUT: if (!signing_validate_output(tx->outputs) || !signing_add_orig_output(tx->outputs)) { return; } idx2++; if (idx2 == output.orig_index + 1) { phase1_request_next_output(); } else if (idx2 < orig_info.outputs_count) { send_req_2_orig_output(); #if !BITCOIN_ONLY } else if (coin->extra_data && tp.extra_data_len > 0) { // has extra data send_req_2_orig_extradata(0, MIN(1024, tp.extra_data_len)); #endif } else { phase1_finish(); } return; #if !BITCOIN_ONLY case STAGE_REQUEST_2_ORIG_EXTRADATA: // Add extra data to original TXID computation. 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 remaining. send_req_2_orig_extradata( tp.extra_data_received, MIN(1024, tp.extra_data_len - tp.extra_data_received)); } else { phase1_finish(); } return; #endif case STAGE_REQUEST_3_INPUT: if (idx1 == 0) { hasher_Reset(&info.hasher_check); } if (!signing_validate_input(tx->inputs)) { return; } if (!tx_input_check_hash(&info.hasher_check, tx->inputs)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to hash input")); signing_abort(); return; } if (!tx->inputs[0].has_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("Expected input with amount")); signing_abort(); return; } memcpy(&input, tx->inputs, sizeof(TxInputType)); if (!fill_input_script_pubkey(coin, &root, &input)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to derive scriptPubKey")); signing_abort(); return; } send_req_3_prev_meta(); return; case STAGE_REQUEST_3_PREV_META: if (tx->outputs_cnt <= input.prev_index) { fsm_sendFailure(FailureType_Failure_DataError, _("Not enough outputs in previous transaction.")); signing_abort(); return; } if (!coin->extra_data && tx->extra_data_len > 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Extra data not enabled on this coin.")); signing_abort(); return; } if (!coin->decred && !coin->overwintered && tx->has_expiry) { fsm_sendFailure(FailureType_Failure_DataError, _("Expiry not enabled on this coin.")); signing_abort(); return; } if (!coin->timestamp && tx->has_timestamp) { fsm_sendFailure(FailureType_Failure_DataError, _("Timestamp not enabled on this coin.")); signing_abort(); return; } if (coin->timestamp && !tx->timestamp) { fsm_sendFailure(FailureType_Failure_DataError, _("Timestamp must be set.")); signing_abort(); return; } if (coin->overwintered) { if (tx->version >= 3 && !tx->has_version_group_id) { fsm_sendFailure(FailureType_Failure_DataError, _("Version group ID must be set when version >= 3.")); signing_abort(); return; } if (tx->version < 3 && tx->has_version_group_id) { fsm_sendFailure( FailureType_Failure_DataError, _("Version group ID must be unset when version < 3.")); signing_abort(); return; } } else { // !coin->overwintered if (tx->has_version_group_id) { fsm_sendFailure(FailureType_Failure_DataError, _("Version group ID not enabled on this coin.")); signing_abort(); return; } if (tx->has_branch_id) { fsm_sendFailure(FailureType_Failure_DataError, _("Branch ID not enabled on this coin.")); signing_abort(); return; } } if (tx->inputs_cnt + tx->outputs_cnt < tx->inputs_cnt) { fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow")); signing_abort(); return; } tx_init(&tp, tx->inputs_cnt, tx->outputs_cnt, tx->version, tx->lock_time, tx->expiry, tx->branch_id, tx->extra_data_len, coin->curve->hasher_sign, coin->overwintered, tx->version_group_id, tx->timestamp); #if !BITCOIN_ONLY if (coin->decred) { tp.version |= (DECRED_SERIALIZE_NO_WITNESS << 16); tp.is_decred = true; } #endif progress_meta_step = progress_step / (tp.inputs_len + tp.outputs_len); idx2 = 0; if (tp.inputs_len > 0) { send_req_3_prev_input(); } else { tx_serialize_header_hash(&tp); send_req_3_prev_output(); } return; case STAGE_REQUEST_3_PREV_INPUT: if (!signing_validate_input(&tx->inputs[0])) { return; } 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_3_prev_input(); } else { idx2 = 0; send_req_3_prev_output(); } return; case STAGE_REQUEST_3_PREV_OUTPUT: if (!signing_validate_bin_output(&tx->bin_outputs[0])) { return; } 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 (input.amount != tx->bin_outputs[0].amount) { fsm_sendFailure(FailureType_Failure_DataError, _("Invalid amount specified")); signing_abort(); return; } if (input.script_pubkey.size != tx->bin_outputs[0].script_pubkey.size || memcmp(input.script_pubkey.bytes, tx->bin_outputs[0].script_pubkey.bytes, input.script_pubkey.size) != 0) { fsm_sendFailure(FailureType_Failure_DataError, _("Input does not match scriptPubKey")); signing_abort(); return; } #if !BITCOIN_ONLY 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; } #endif } if (idx2 < tp.outputs_len - 1) { /* Check prevtx of next input */ idx2++; send_req_3_prev_output(); #if !BITCOIN_ONLY } else if (coin->extra_data && tp.extra_data_len > 0) { // has extra data send_req_3_prev_extradata(0, MIN(1024, tp.extra_data_len)); return; #endif } else { /* prevtx is done */ if (!signing_check_prevtx_hash()) { return; } } return; #if !BITCOIN_ONLY case STAGE_REQUEST_3_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 remaining send_req_3_prev_extradata( tp.extra_data_received, MIN(1024, tp.extra_data_len - tp.extra_data_received)); } else { if (!signing_check_prevtx_hash()) { return; } } return; #endif case STAGE_REQUEST_3_ORIG_NONLEGACY_INPUT: if (!signing_validate_input(tx->inputs)) { return; } // Add input to the outer transaction check. if (!tx_input_check_hash(&hasher_check, tx->inputs)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to hash input")); signing_abort(); return; } if (!signing_verify_orig_nonlegacy_input(tx->inputs)) { return; } idx1++; phase2_request_orig_input(); return; case STAGE_REQUEST_3_ORIG_INPUT: if (!signing_validate_input(tx->inputs) || !signing_hash_orig_input(tx->inputs)) { return; } idx2++; if (idx2 < orig_info.inputs_count) { send_req_3_orig_input(); } else { // Ensure that the original transaction inputs haven't changed for the // inner transaction check. if (!tx_info_check_inputs_hash(&orig_info)) { return; } // Reset the inner transaction check. hasher_Reset(&orig_info.hasher_check); idx2 = 0; send_req_3_orig_output(); } return; case STAGE_REQUEST_3_ORIG_OUTPUT: if (!signing_validate_output(tx->outputs) || !signing_hash_orig_output(tx->outputs)) { return; } idx2++; if (idx2 < orig_info.outputs_count) { send_req_3_orig_output(); } else { // Ensure that the original transaction outputs haven't changed for the // inner transaction check. if (!tx_info_check_outputs_hash(&orig_info)) { return; } // Verify original signature. if (!signing_verify_orig_legacy_input()) { return; } idx1++; phase2_request_orig_input(); } return; case STAGE_REQUEST_4_INPUT: if (!signing_validate_input(&tx->inputs[0])) { return; } progress = 500 + ((signatures * progress_step + idx2 * progress_meta_step) >> PROGRESS_PRECISION); if (idx2 == 0) { tx_init(&ti, info.inputs_count, info.outputs_count, info.version, info.lock_time, info.expiry, tx->branch_id, 0, coin->curve->hasher_sign, coin->overwintered, info.version_group_id, info.timestamp); hasher_Reset(&info.hasher_check); } // check inputs are the same as those in phase 1 if (!tx_input_check_hash(&info.hasher_check, tx->inputs)) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to hash input")); signing_abort(); return; } if (idx2 == idx1) { if (!tx_info_check_input(&info, &tx->inputs[0]) || !derive_node(&tx->inputs[0]) || !fill_input_script_sig(&tx->inputs[0])) { return; } memcpy(&input, &tx->inputs[0], sizeof(input)); memcpy(privkey, node.private_key, 32); memcpy(pubkey, node.public_key, 33); } else { if (info.next_legacy_input == idx1 && idx2 > idx1 && (tx->inputs[0].script_type == InputScriptType_SPENDADDRESS || tx->inputs[0].script_type == InputScriptType_SPENDMULTISIG)) { info.next_legacy_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 < info.inputs_count - 1) { idx2++; send_req_4_input(); } else { if (!tx_info_check_inputs_hash(&info)) { return; } hasher_Reset(&info.hasher_check); idx2 = 0; send_req_4_output(); } return; case STAGE_REQUEST_4_OUTPUT: if (!signing_validate_output(&tx->outputs[0])) { return; } progress = 500 + ((signatures * progress_step + (info.inputs_count + idx2) * progress_meta_step) >> PROGRESS_PRECISION); if (compile_output(coin, amount_unit, &root, tx->outputs, &bin_output, false) <= 0) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to compile output")); signing_abort(); return; } // check hashOutputs tx_output_hash(&info.hasher_check, &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 < info.outputs_count - 1) { idx2++; send_req_4_output(); } else { if (!tx_info_check_outputs_hash(&info) || !signing_sign_legacy_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 < info.inputs_count - 1) { idx1++; phase2_request_next_input(); } else { idx1 = 0; send_req_5_output(); } } return; case STAGE_REQUEST_NONLEGACY_INPUT: if (!signing_validate_input(&tx->inputs[0])) { return; } if (is_external_input(idx1) != (tx->inputs[0].script_type == InputScriptType_EXTERNAL)) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return; } 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 || coin->overwintered) || taproot_only) { fsm_sendFailure(FailureType_Failure_DataError, _("Transaction has changed during signing")); signing_abort(); return; } if (!tx_info_check_input(&info, &tx->inputs[0]) || !derive_node(&tx->inputs[0]) || !fill_input_script_sig(&tx->inputs[0])) { return; } if (!tx->inputs[0].has_amount) { fsm_sendFailure(FailureType_Failure_DataError, _("Expected input with amount")); signing_abort(); return; } uint8_t hash[32] = {0}; #if !BITCOIN_ONLY if (coin->overwintered) { if (info.version == 4) { signing_hash_zip243(&info, &tx->inputs[0], hash); } else if (info.version == 5) { if (!fill_input_script_pubkey(coin, &root, &tx->inputs[0])) { fsm_sendFailure(FailureType_Failure_ProcessError, _("Failed to derive scriptPubKey")); signing_abort(); return; } signing_hash_zip244(&info, &tx->inputs[0], hash); } else { fsm_sendFailure( FailureType_Failure_DataError, _("Unsupported version for overwintered transaction")); signing_abort(); return; } } else #endif { signing_hash_bip143(&info, &tx->inputs[0], hash); } if (!signing_sign_ecdsa(&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 (!tx_info_check_input(&info, &tx->inputs[0]) || !derive_node(&tx->inputs[0]) || !fill_input_script_sig(&tx->inputs[0])) { 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 if (tx->inputs[0].script_type == InputScriptType_EXTERNAL && tx->inputs[0].has_script_sig) { // use the provided script_sig } 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 < info.inputs_count - 1) { idx1++; phase2_request_next_input(); } else { idx1 = 0; send_req_5_output(); } return; case STAGE_REQUEST_5_OUTPUT: if (!signing_validate_output(&tx->outputs[0])) { return; } if (compile_output(coin, amount_unit, &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 < info.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_validate_input(&tx->inputs[0])) { return; } 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 < info.inputs_count - 1) { idx1++; send_req_segwit_witness(); } else { send_req_finished(); signing_abort(); } return; #if !BITCOIN_ONLY case STAGE_REQUEST_DECRED_WITNESS: if (!signing_validate_input(&tx->inputs[0])) { return; } progress = 500 + ((signatures * progress_step + idx2 * progress_meta_step) >> PROGRESS_PRECISION); if (idx1 == 0) { // witness tx_init(&to, info.inputs_count, info.outputs_count, info.version, info.lock_time, info.expiry, tx->branch_id, 0, coin->curve->hasher_sign, coin->overwintered, info.version_group_id, info.timestamp); to.is_decred = true; } // witness hash tx_init(&ti, info.inputs_count, info.outputs_count, info.version, info.lock_time, info.expiry, tx->branch_id, 0, coin->curve->hasher_sign, coin->overwintered, info.version_group_id, info.timestamp); ti.version |= (DECRED_SERIALIZE_WITNESS_SIGNING << 16); ti.is_decred = true; if (!tx_info_check_input(&info, &tx->inputs[0]) || !derive_node(&tx->inputs[0]) || !fill_input_script_sig(&tx->inputs[0])) { return; } for (idx2 = 0; idx2 < info.inputs_count; idx2++) { uint32_t r = 0; 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 < info.inputs_count - 1) { idx1++; send_req_decred_witness(); } else { send_req_finished(); signing_abort(); } return; #endif } fsm_sendFailure(FailureType_Failure_ProcessError, _("Signing error")); signing_abort(); } void signing_abort(void) { if (signing) { layoutHome(); signing = false; } memzero(&root, sizeof(root)); memzero(&node, sizeof(node)); }