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trezor-firmware/legacy/firmware/signing.c

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/*
* This file is part of the Trezor project, https://trezor.io/
*
* Copyright (C) 2014 Pavol Rusnak <stick@satoshilabs.com>
*
* 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 <http://www.gnu.org/licenses/>.
*/
#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"
#ifdef USE_SECP256K1_ZKP_ECDSA
#include "zkp_ecdsa.h"
#endif
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);
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);
}
#ifdef USE_SECP256K1_ZKP_ECDSA
if (coin->curve->params == &secp256k1) {
valid = zkp_ecdsa_verify_digest(coin->curve->params, node.public_key, sig,
hash) == 0;
} else
#endif
{
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 = false;
#ifdef USE_SECP256K1_ZKP_ECDSA
if (coin->curve->params == &secp256k1) {
valid = zkp_ecdsa_verify_digest(coin->curve->params, node.public_key, sig,
hash) == 0;
} else
#endif
{
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;
int ret = 0;
#ifdef USE_SECP256K1_ZKP_ECDSA
if (coin->curve->params == &secp256k1) {
ret = zkp_ecdsa_sign_digest(coin->curve->params, private_key, hash, sig,
NULL, NULL);
} else
#endif
{
ret = ecdsa_sign_digest(coin->curve->params, private_key, hash, sig, NULL,
NULL);
}
if (ret != 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 <digest> 88 AC to 16 00 14 <digest>
// 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));
}
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