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signing.c
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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 "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"
static uint32_t inputs_count;
static uint32_t outputs_count;
static const CoinInfo *coin;
static CONFIDENTIAL HDNode root;
static CONFIDENTIAL HDNode node;
static bool signing = false;
enum {
STAGE_REQUEST_1_INPUT,
STAGE_REQUEST_2_PREV_META,
STAGE_REQUEST_2_PREV_INPUT,
STAGE_REQUEST_2_PREV_OUTPUT,
STAGE_REQUEST_2_PREV_EXTRADATA,
STAGE_REQUEST_3_OUTPUT,
STAGE_REQUEST_4_INPUT,
STAGE_REQUEST_4_OUTPUT,
STAGE_REQUEST_SEGWIT_INPUT,
STAGE_REQUEST_5_OUTPUT,
STAGE_REQUEST_SEGWIT_WITNESS,
STAGE_REQUEST_DECRED_WITNESS
} signing_stage;
static uint32_t idx1, idx2;
static uint32_t signatures;
static TxRequest resp;
static TxInputType input;
static TxOutputBinType bin_output;
static TxStruct to, tp, ti;
static Hasher hasher_prevouts, hasher_sequence, hasher_outputs, hasher_check;
static uint8_t CONFIDENTIAL privkey[32];
static uint8_t pubkey[33], sig[64];
static uint8_t hash_prevouts[32], hash_sequence[32], hash_outputs[32];
static uint8_t hash_prefix[32];
static uint8_t hash_check[32];
static uint64_t to_spend, authorized_amount, spending, change_spend;
static uint32_t version = 1;
static uint32_t lock_time = 0;
static uint32_t expiry = 0;
static bool overwintered = false;
static uint32_t version_group_id = 0;
static uint32_t branch_id = 0;
static uint32_t next_nonsegwit_input;
static uint32_t progress, progress_step, progress_meta_step;
static bool multisig_fp_set, multisig_fp_mismatch;
static uint8_t multisig_fp[32];
static uint32_t in_address_n[8];
static size_t in_address_n_count;
static uint32_t tx_weight;
/* A marker for in_address_n_count to indicate a mismatch in bip32 paths in
input */
#define BIP32_NOCHANGEALLOWED 1
/* The number of bip32 levels used in a wallet (chain and address) */
#define BIP32_WALLET_DEPTH 2
/* The chain id used for change */
#define BIP32_CHANGE_CHAIN 1
/* The maximum allowed change address. This should be large enough for normal
use and still allow to quickly brute-force the correct bip32 path. */
#define BIP32_MAX_LAST_ELEMENT 1000000
/* transaction header size: 4 byte version */
#define TXSIZE_HEADER 4
/* transaction footer size: 4 byte lock time */
#define TXSIZE_FOOTER 4
/* transaction segwit overhead 2 marker */
#define TXSIZE_SEGWIT_OVERHEAD 2
enum {
SIGHASH_ALL = 1,
SIGHASH_FORKID = 0x40,
};
enum {
DECRED_SERIALIZE_FULL = 0,
DECRED_SERIALIZE_NO_WITNESS = 1,
DECRED_SERIALIZE_WITNESS_SIGNING = 3,
};
/* progress_step/meta_step are fixed point numbers, giving the
* progress per input in permille with these many additional bits.
*/
#define PROGRESS_PRECISION 16
/*
Workflow of streamed signing
The STAGE_ constants describe the signing_stage when request is sent.
I - input
O - output
Phase1 - check inputs, previous transactions, and outputs
- ask for confirmations
- check fee
=========================================================
foreach I (idx1):
Request I STAGE_REQUEST_1_INPUT Add I to segwit hash_prevouts, hash_sequence
Add I to Decred hash_prefix
Add I to TransactionChecksum (prevout and type)
if (Decred)
Return I
If not segwit, Calculate amount of I:
Request prevhash I, META STAGE_REQUEST_2_PREV_META foreach prevhash I
(idx2): Request prevhash I STAGE_REQUEST_2_PREV_INPUT foreach prevhash O (idx2):
Request prevhash O STAGE_REQUEST_2_PREV_OUTPUT Add amount of
prevhash O (which is amount of I) Request prevhash extra data (if applicable)
STAGE_REQUEST_2_PREV_EXTRADATA Calculate hash of streamed tx, compare to
prevhash I foreach O (idx1): Request O STAGE_REQUEST_3_OUTPUT Add O to Decred
hash_prefix Add O to TransactionChecksum if (Decred) Return O Display output Ask
for confirmation
Check tx fee
Ask for confirmation
Phase2: sign inputs, check that nothing changed
===============================================
if (Decred)
Skip to STAGE_REQUEST_DECRED_WITNESS
foreach I (idx1): // input to sign
if (idx1 is segwit)
Request I STAGE_REQUEST_SEGWIT_INPUT Return serialized input chunk
else
foreach I (idx2):
Request I STAGE_REQUEST_4_INPUT If idx1 == idx2 Fill scriptsig
Remember key for signing
Add I to StreamTransactionSign
Add I to TransactionChecksum
foreach O (idx2):
Request O STAGE_REQUEST_4_OUTPUT Add O to StreamTransactionSign Add
O to TransactionChecksum
Compare TransactionChecksum with checksum computed in Phase 1
If different:
Failure
Sign StreamTransactionSign
Return signed chunk
foreach O (idx1):
Request O STAGE_REQUEST_5_OUTPUT Rewrite change address Return O
Phase3: sign segwit inputs, check that nothing changed
===============================================
foreach I (idx1): // input to sign
Request I STAGE_REQUEST_SEGWIT_WITNESS Check amount Sign segwit prevhash,
sequence, amount, outputs Return witness
Phase3: sign Decred inputs
==========================
foreach I (idx1): // input to sign STAGE_REQUEST_DECRED_WITNESS Request I Fill
scriptSig Compute hash_witness
Sign (hash_type || hash_prefix || hash_witness)
Return witness
*/
void send_req_1_input(void) {
signing_stage = STAGE_REQUEST_1_INPUT;
resp.has_request_type = true;
resp.request_type = RequestType_TXINPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx1;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_2_prev_meta(void) {
signing_stage = STAGE_REQUEST_2_PREV_META;
resp.has_request_type = true;
resp.request_type = RequestType_TXMETA;
resp.has_details = true;
resp.details.has_tx_hash = true;
resp.details.tx_hash.size = input.prev_hash.size;
memcpy(resp.details.tx_hash.bytes, input.prev_hash.bytes,
input.prev_hash.size);
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_2_prev_input(void) {
signing_stage = STAGE_REQUEST_2_PREV_INPUT;
resp.has_request_type = true;
resp.request_type = RequestType_TXINPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx2;
resp.details.has_tx_hash = true;
resp.details.tx_hash.size = input.prev_hash.size;
memcpy(resp.details.tx_hash.bytes, input.prev_hash.bytes,
resp.details.tx_hash.size);
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_2_prev_output(void) {
signing_stage = STAGE_REQUEST_2_PREV_OUTPUT;
resp.has_request_type = true;
resp.request_type = RequestType_TXOUTPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx2;
resp.details.has_tx_hash = true;
resp.details.tx_hash.size = input.prev_hash.size;
memcpy(resp.details.tx_hash.bytes, input.prev_hash.bytes,
resp.details.tx_hash.size);
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_2_prev_extradata(uint32_t chunk_offset, uint32_t chunk_len) {
signing_stage = STAGE_REQUEST_2_PREV_EXTRADATA;
resp.has_request_type = true;
resp.request_type = RequestType_TXEXTRADATA;
resp.has_details = true;
resp.details.has_extra_data_offset = true;
resp.details.extra_data_offset = chunk_offset;
resp.details.has_extra_data_len = true;
resp.details.extra_data_len = chunk_len;
resp.details.has_tx_hash = true;
resp.details.tx_hash.size = input.prev_hash.size;
memcpy(resp.details.tx_hash.bytes, input.prev_hash.bytes,
resp.details.tx_hash.size);
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_3_output(void) {
signing_stage = STAGE_REQUEST_3_OUTPUT;
resp.has_request_type = true;
resp.request_type = RequestType_TXOUTPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx1;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_4_input(void) {
signing_stage = STAGE_REQUEST_4_INPUT;
resp.has_request_type = true;
resp.request_type = RequestType_TXINPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx2;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_4_output(void) {
signing_stage = STAGE_REQUEST_4_OUTPUT;
resp.has_request_type = true;
resp.request_type = RequestType_TXOUTPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx2;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_segwit_input(void) {
signing_stage = STAGE_REQUEST_SEGWIT_INPUT;
resp.has_request_type = true;
resp.request_type = RequestType_TXINPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx1;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_segwit_witness(void) {
signing_stage = STAGE_REQUEST_SEGWIT_WITNESS;
resp.has_request_type = true;
resp.request_type = RequestType_TXINPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx1;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_decred_witness(void) {
signing_stage = STAGE_REQUEST_DECRED_WITNESS;
resp.has_request_type = true;
resp.request_type = RequestType_TXINPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx1;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_5_output(void) {
signing_stage = STAGE_REQUEST_5_OUTPUT;
resp.has_request_type = true;
resp.request_type = RequestType_TXOUTPUT;
resp.has_details = true;
resp.details.has_request_index = true;
resp.details.request_index = idx1;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void send_req_finished(void) {
resp.has_request_type = true;
resp.request_type = RequestType_TXFINISHED;
msg_write(MessageType_MessageType_TxRequest, &resp);
}
void phase1_request_next_input(void) {
if (idx1 < inputs_count - 1) {
idx1++;
send_req_1_input();
} else {
// compute segwit hashPrevouts & hashSequence
hasher_Final(&hasher_prevouts, hash_prevouts);
hasher_Final(&hasher_sequence, hash_sequence);
hasher_Final(&hasher_check, hash_check);
// init hashOutputs
hasher_Reset(&hasher_outputs);
idx1 = 0;
send_req_3_output();
}
}
void phase2_request_next_input(void) {
if (idx1 == next_nonsegwit_input) {
idx2 = 0;
send_req_4_input();
} else {
send_req_segwit_input();
}
}
void extract_input_bip32_path(const TxInputType *tinput) {
if (in_address_n_count == BIP32_NOCHANGEALLOWED) {
return;
}
size_t count = tinput->address_n_count;
if (count < BIP32_WALLET_DEPTH) {
// no change address allowed
in_address_n_count = BIP32_NOCHANGEALLOWED;
return;
}
if (in_address_n_count == 0) {
// initialize in_address_n on first input seen
in_address_n_count = count;
// store the bip32 path up to the account
memcpy(in_address_n, tinput->address_n,
(count - BIP32_WALLET_DEPTH) * sizeof(uint32_t));
return;
}
// check that all addresses use a path of same length
if (in_address_n_count != count) {
in_address_n_count = BIP32_NOCHANGEALLOWED;
return;
}
// check that the bip32 path up to the account matches
if (memcmp(in_address_n, tinput->address_n,
(count - BIP32_WALLET_DEPTH) * sizeof(uint32_t)) != 0) {
// mismatch -> no change address allowed
in_address_n_count = BIP32_NOCHANGEALLOWED;
return;
}
}
bool check_change_bip32_path(const TxOutputType *toutput) {
size_t count = toutput->address_n_count;
// Check that the change path has the same bip32 path length,
// the same path up to the account, and that the wallet components
// (chain id and address) are as expected.
// Note: count >= BIP32_WALLET_DEPTH and count == in_address_n_count
// imply that in_address_n_count != BIP32_NOCHANGEALLOWED
return (count >= BIP32_WALLET_DEPTH && count == in_address_n_count &&
0 == memcmp(in_address_n, toutput->address_n,
(count - BIP32_WALLET_DEPTH) * sizeof(uint32_t)) &&
toutput->address_n[count - 2] <= BIP32_CHANGE_CHAIN &&
toutput->address_n[count - 1] <= BIP32_MAX_LAST_ELEMENT);
}
bool compile_input_script_sig(TxInputType *tinput) {
if (!multisig_fp_mismatch) {
// check that this is still multisig
uint8_t h[32];
if (!tinput->has_multisig ||
cryptoMultisigFingerprint(&(tinput->multisig), h) == 0 ||
memcmp(multisig_fp, h, 32) != 0) {
// Transaction has changed during signing
return false;
}
}
if (in_address_n_count != BIP32_NOCHANGEALLOWED) {
// check that input address didn't change
size_t count = tinput->address_n_count;
if (count < 2 || count != in_address_n_count ||
0 != memcmp(in_address_n, tinput->address_n,
(count - 2) * sizeof(uint32_t))) {
return false;
}
}
memcpy(&node, &root, sizeof(HDNode));
if (hdnode_private_ckd_cached(&node, tinput->address_n,
tinput->address_n_count, NULL) == 0) {
// Failed to derive private key
return false;
}
hdnode_fill_public_key(&node);
if (tinput->has_multisig) {
tinput->script_sig.size = compile_script_multisig(coin, &(tinput->multisig),
tinput->script_sig.bytes);
} else { // SPENDADDRESS
uint8_t hash[20];
ecdsa_get_pubkeyhash(node.public_key, coin->curve->hasher_pubkey, hash);
tinput->script_sig.size =
compile_script_sig(coin->address_type, hash, tinput->script_sig.bytes);
}
return tinput->script_sig.size > 0;
}
void signing_init(const SignTx *msg, const CoinInfo *_coin,
const HDNode *_root) {
inputs_count = msg->inputs_count;
outputs_count = msg->outputs_count;
coin = _coin;
memcpy(&root, _root, sizeof(HDNode));
version = msg->version;
lock_time = msg->lock_time;
expiry = msg->expiry;
overwintered = msg->has_overwintered && msg->overwintered;
version_group_id = msg->version_group_id;
branch_id = msg->branch_id;
// set default values for Zcash if branch_id is unset
if (overwintered && (branch_id == 0)) {
switch (version) {
case 3:
branch_id = 0x5BA81B19; // Overwinter
break;
case 4:
branch_id = 0x76B809BB; // Sapling
break;
}
}
uint32_t size = TXSIZE_HEADER + TXSIZE_FOOTER +
ser_length_size(inputs_count) +
ser_length_size(outputs_count);
if (coin->decred) {
size += 4; // Decred expiry
size += ser_length_size(inputs_count); // Witness inputs count
}
tx_weight = 4 * size;
signatures = 0;
idx1 = 0;
to_spend = 0;
spending = 0;
change_spend = 0;
authorized_amount = 0;
memzero(&input, sizeof(TxInputType));
memzero(&resp, sizeof(TxRequest));
signing = true;
progress = 0;
// we step by 500/inputs_count per input in phase1 and phase2
// this means 50 % per phase.
progress_step = (500 << PROGRESS_PRECISION) / inputs_count;
in_address_n_count = 0;
multisig_fp_set = false;
multisig_fp_mismatch = false;
next_nonsegwit_input = 0xffffffff;
tx_init(&to, inputs_count, outputs_count, version, lock_time, expiry, 0,
coin->curve->hasher_sign, overwintered, version_group_id);
if (coin->decred) {
to.version |= (DECRED_SERIALIZE_FULL << 16);
to.is_decred = true;
tx_init(&ti, inputs_count, outputs_count, version, lock_time, expiry, 0,
coin->curve->hasher_sign, overwintered, version_group_id);
ti.version |= (DECRED_SERIALIZE_NO_WITNESS << 16);
ti.is_decred = true;
}
// segwit hashes for hashPrevouts and hashSequence
if (overwintered) {
hasher_InitParam(&hasher_prevouts, HASHER_BLAKE2B_PERSONAL,
"ZcashPrevoutHash", 16);
hasher_InitParam(&hasher_sequence, HASHER_BLAKE2B_PERSONAL,
"ZcashSequencHash", 16);
hasher_InitParam(&hasher_outputs, HASHER_BLAKE2B_PERSONAL,
"ZcashOutputsHash", 16);
hasher_Init(&hasher_check, coin->curve->hasher_sign);
} else {
hasher_Init(&hasher_prevouts, coin->curve->hasher_sign);
hasher_Init(&hasher_sequence, coin->curve->hasher_sign);
hasher_Init(&hasher_outputs, coin->curve->hasher_sign);
hasher_Init(&hasher_check, coin->curve->hasher_sign);
}
layoutProgressSwipe(_("Signing transaction"), 0);
send_req_1_input();
}
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
static bool signing_check_input(const TxInputType *txinput) {
/* compute multisig fingerprint */
/* (if all input share the same fingerprint, outputs having the same
* fingerprint will be considered as change outputs) */
if (txinput->has_multisig && !multisig_fp_mismatch) {
uint8_t h[32];
if (cryptoMultisigFingerprint(&txinput->multisig, h) == 0) {
fsm_sendFailure(FailureType_Failure_ProcessError,
_("Error computing multisig fingerprint"));
signing_abort();
return false;
}
if (multisig_fp_set) {
if (memcmp(multisig_fp, h, 32) != 0) {
multisig_fp_mismatch = true;
}
} else {
memcpy(multisig_fp, h, 32);
multisig_fp_set = true;
}
} else { // single signature
multisig_fp_mismatch = true;
}
// remember the input bip32 path
// change addresses must use the same bip32 path as all inputs
extract_input_bip32_path(txinput);
// compute segwit hashPrevouts & hashSequence
tx_prevout_hash(&hasher_prevouts, txinput);
tx_sequence_hash(&hasher_sequence, txinput);
if (coin->decred) {
if (txinput->decred_script_version > 0) {
fsm_sendFailure(FailureType_Failure_DataError,
_("Decred v1+ scripts are not supported"));
signing_abort();
return false;
}
// serialize Decred prefix in Phase 1
resp.has_serialized = true;
resp.serialized.has_serialized_tx = true;
resp.serialized.serialized_tx.size =
tx_serialize_input(&to, txinput, resp.serialized.serialized_tx.bytes);
// compute Decred hashPrefix
tx_serialize_input_hash(&ti, txinput);
}
// hash prevout and script type to check it later (relevant for fee
// computation)
tx_prevout_hash(&hasher_check, txinput);
hasher_Update(&hasher_check, (const uint8_t *)&txinput->script_type,
sizeof(&txinput->script_type));
return true;
}
// check if the hash of the prevtx matches
static bool signing_check_prevtx_hash(void) {
uint8_t hash[32];
tx_hash_final(&tp, hash, true);
if (memcmp(hash, input.prev_hash.bytes, 32) != 0) {
fsm_sendFailure(FailureType_Failure_DataError,
_("Encountered invalid prevhash"));
signing_abort();
return false;
}
phase1_request_next_input();
return true;
}
static bool signing_check_output(TxOutputType *txoutput) {
// Phase1: Check outputs
// add it to hash_outputs
// ask user for permission
// check for change address
bool is_change = false;
if (txoutput->address_n_count > 0) {
if (txoutput->has_address) {
fsm_sendFailure(FailureType_Failure_DataError,
_("Address in change output"));
signing_abort();
return false;
}
/*
* For multisig check that all inputs are multisig
*/
if (txoutput->has_multisig) {
uint8_t h[32];
if (multisig_fp_set && !multisig_fp_mismatch &&
cryptoMultisigFingerprint(&(txoutput->multisig), h) &&
memcmp(multisig_fp, h, 32) == 0) {
is_change = check_change_bip32_path(txoutput);
}
} else {
is_change = check_change_bip32_path(txoutput);
}
/*
* only allow segwit change if amount is smaller than what segwit inputs
* paid. this was added during the times segwit was not yet fully activated
* to make sure the user is not tricked to use witness change output
* instead of regular one therefore creating ANYONECANSPEND output
*/
if ((txoutput->script_type == OutputScriptType_PAYTOWITNESS ||
txoutput->script_type == OutputScriptType_PAYTOP2SHWITNESS) &&
txoutput->amount > authorized_amount) {
is_change = false;
}
}
if (is_change) {
if (change_spend == 0) { // not set
change_spend = txoutput->amount;
} else {
/* We only skip confirmation for the first change output */
is_change = false;
}
}
if (spending + txoutput->amount < spending) {
fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow"));
signing_abort();
return false;
}
spending += txoutput->amount;
int co = compile_output(coin, &root, txoutput, &bin_output, !is_change);
if (!is_change) {
layoutProgress(_("Signing transaction"), progress);
}
if (co < 0) {
fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
signing_abort();
return false;
} else if (co == 0) {
fsm_sendFailure(FailureType_Failure_ProcessError,
_("Failed to compile output"));
signing_abort();
return false;
}
if (coin->decred) {
// serialize Decred prefix in Phase 1
resp.has_serialized = true;
resp.serialized.has_serialized_tx = true;
resp.serialized.serialized_tx.size = tx_serialize_output(
&to, &bin_output, resp.serialized.serialized_tx.bytes);
// compute Decred hashPrefix
tx_serialize_output_hash(&ti, &bin_output);
}
// compute segwit hashOuts
tx_output_hash(&hasher_outputs, &bin_output, coin->decred);
return true;
}
static bool signing_check_fee(void) {
// check fees
if (spending > to_spend) {
fsm_sendFailure(FailureType_Failure_NotEnoughFunds, _("Not enough funds"));
signing_abort();
return false;
}
uint64_t fee = to_spend - spending;
if (fee > ((uint64_t)tx_weight * coin->maxfee_kb) / 4000) {
layoutFeeOverThreshold(coin, fee);
if (!protectButton(ButtonRequestType_ButtonRequest_FeeOverThreshold,
false)) {
fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
signing_abort();
return false;
}
}
// last confirmation
layoutConfirmTx(coin, to_spend - change_spend, fee);
if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) {
fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
signing_abort();
return false;
}
return true;
}
static uint32_t signing_hash_type(void) {
uint32_t hash_type = SIGHASH_ALL;
if (coin->has_fork_id) {
hash_type |= (coin->fork_id << 8) | SIGHASH_FORKID;
}
return hash_type;
}
static void phase1_request_next_output(void) {
if (idx1 < outputs_count - 1) {
idx1++;
send_req_3_output();
} else {
if (coin->decred) {
// compute Decred hashPrefix
tx_hash_final(&ti, hash_prefix, false);
}
hasher_Final(&hasher_outputs, hash_outputs);
if (!signing_check_fee()) {
return;
}
// Everything was checked, now phase 2 begins and the transaction is signed.
progress_meta_step = progress_step / (inputs_count + outputs_count);
layoutProgress(_("Signing transaction"), progress);
idx1 = 0;
if (coin->decred) {
// Decred prefix serialized in Phase 1, skip Phase 2
send_req_decred_witness();
} else {
phase2_request_next_input();
}
}
}
static void signing_hash_bip143(const TxInputType *txinput, uint8_t *hash) {
uint32_t hash_type = signing_hash_type();
Hasher hasher_preimage;
hasher_Init(&hasher_preimage, coin->curve->hasher_sign);
hasher_Update(&hasher_preimage, (const uint8_t *)&version, 4); // nVersion
hasher_Update(&hasher_preimage, hash_prevouts, 32); // hashPrevouts
hasher_Update(&hasher_preimage, hash_sequence, 32); // hashSequence
tx_prevout_hash(&hasher_preimage, txinput); // outpoint
tx_script_hash(&hasher_preimage, txinput->script_sig.size,
txinput->script_sig.bytes); // scriptCode
hasher_Update(&hasher_preimage, (const uint8_t *)&txinput->amount,
8); // amount
tx_sequence_hash(&hasher_preimage, txinput); // nSequence
hasher_Update(&hasher_preimage, hash_outputs, 32); // hashOutputs
hasher_Update(&hasher_preimage, (const uint8_t *)&lock_time, 4); // nLockTime
hasher_Update(&hasher_preimage, (const uint8_t *)&hash_type, 4); // nHashType
hasher_Final(&hasher_preimage, hash);
}
static void signing_hash_zip143(const TxInputType *txinput, uint8_t *hash) {
uint32_t hash_type = signing_hash_type();
uint8_t personal[16];
memcpy(personal, "ZcashSigHash", 12);
memcpy(personal + 12, &branch_id, 4);
Hasher hasher_preimage;
hasher_InitParam(&hasher_preimage, HASHER_BLAKE2B_PERSONAL, personal,
sizeof(personal));
uint32_t ver = version | TX_OVERWINTERED; // 1. nVersion | fOverwintered
hasher_Update(&hasher_preimage, (const uint8_t *)&ver, 4);
hasher_Update(&hasher_preimage, (const uint8_t *)&version_group_id,
4); // 2. nVersionGroupId
hasher_Update(&hasher_preimage, hash_prevouts, 32); // 3. hashPrevouts
hasher_Update(&hasher_preimage, hash_sequence, 32); // 4. hashSequence
hasher_Update(&hasher_preimage, hash_outputs, 32); // 5. hashOutputs
// 6. hashJoinSplits
hasher_Update(&hasher_preimage, (const uint8_t *)"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 32);
hasher_Update(&hasher_preimage, (const uint8_t *)&lock_time,
4); // 7. nLockTime
hasher_Update(&hasher_preimage, (const uint8_t *)&expiry,
4); // 8. expiryHeight
hasher_Update(&hasher_preimage, (const uint8_t *)&hash_type,
4); // 9. nHashType
tx_prevout_hash(&hasher_preimage, txinput); // 10a. outpoint
tx_script_hash(&hasher_preimage, txinput->script_sig.size,
txinput->script_sig.bytes); // 10b. scriptCode
hasher_Update(&hasher_preimage, (const uint8_t *)&txinput->amount,
8); // 10c. value
tx_sequence_hash(&hasher_preimage, txinput); // 10d. nSequence
hasher_Final(&hasher_preimage, hash);
}
static void signing_hash_zip243(const TxInputType *txinput, uint8_t *hash) {
uint32_t hash_type = signing_hash_type();
uint8_t personal[16];
memcpy(personal, "ZcashSigHash", 12);
memcpy(personal + 12, &branch_id, 4);
Hasher hasher_preimage;
hasher_InitParam(&hasher_preimage, HASHER_BLAKE2B_PERSONAL, personal,
sizeof(personal));
uint32_t ver = version | TX_OVERWINTERED; // 1. nVersion | fOverwintered
hasher_Update(&hasher_preimage, (const uint8_t *)&ver, 4);
hasher_Update(&hasher_preimage, (const uint8_t *)&version_group_id,
4); // 2. nVersionGroupId
hasher_Update(&hasher_preimage, hash_prevouts, 32); // 3. hashPrevouts
hasher_Update(&hasher_preimage, hash_sequence, 32); // 4. hashSequence
hasher_Update(&hasher_preimage, hash_outputs, 32); // 5. hashOutputs
// 6. hashJoinSplits
hasher_Update(&hasher_preimage, (const uint8_t *)"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 32);
// 7. hashShieldedSpends
hasher_Update(&hasher_preimage, (const uint8_t *)"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 32);
// 8. hashShieldedOutputs
hasher_Update(&hasher_preimage, (const uint8_t *)"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 32);
hasher_Update(&hasher_preimage, (const uint8_t *)&lock_time,
4); // 9. nLockTime
hasher_Update(&hasher_preimage, (const uint8_t *)&expiry,
4); // 10. expiryHeight
hasher_Update(&hasher_preimage,
(const uint8_t *)"\x00\x00\x00\x00\x00\x00\x00\x00",
8); // 11. valueBalance
hasher_Update(&hasher_preimage, (const uint8_t *)&hash_type,
4); // 12. nHashType
tx_prevout_hash(&hasher_preimage, txinput); // 13a. outpoint
tx_script_hash(&hasher_preimage, txinput->script_sig.size,
txinput->script_sig.bytes); // 13b. scriptCode
hasher_Update(&hasher_preimage, (const uint8_t *)&txinput->amount,
8); // 13c. value
tx_sequence_hash(&hasher_preimage, txinput); // 13d. nSequence
hasher_Final(&hasher_preimage, hash);
}
static void signing_hash_decred(const uint8_t *hash_witness, uint8_t *hash) {
uint32_t hash_type = signing_hash_type();
Hasher hasher_preimage;
hasher_Init(&hasher_preimage, coin->curve->hasher_sign);
hasher_Update(&hasher_preimage, (const uint8_t *)&hash_type, 4);
hasher_Update(&hasher_preimage, hash_prefix, 32);
hasher_Update(&hasher_preimage, hash_witness, 32);
hasher_Final(&hasher_preimage, hash);
}
static bool signing_sign_hash(TxInputType *txinput, const uint8_t *private_key,
const uint8_t *public_key, const uint8_t *hash) {
resp.serialized.has_signature_index = true;
resp.serialized.signature_index = idx1;
resp.serialized.has_signature = true;
resp.serialized.has_serialized_tx = true;
if (ecdsa_sign_digest(coin->curve->params, private_key, hash, sig, NULL,
NULL) != 0) {
fsm_sendFailure(FailureType_Failure_ProcessError, _("Signing failed"));
signing_abort();
return false;
}
resp.serialized.signature.size =
ecdsa_sig_to_der(sig, resp.serialized.signature.bytes);
uint8_t sighash = signing_hash_type() & 0xff;
if (txinput->has_multisig) {
// fill in the signature
int pubkey_idx =
cryptoMultisigPubkeyIndex(coin, &(txinput->multisig), public_key);
if (pubkey_idx < 0) {
fsm_sendFailure(FailureType_Failure_DataError,
_("Pubkey not found in multisig script"));
signing_abort();
return false;
}
memcpy(txinput->multisig.signatures[pubkey_idx].bytes,
resp.serialized.signature.bytes, resp.serialized.signature.size);
txinput->multisig.signatures[pubkey_idx].size =
resp.serialized.signature.size;
txinput->script_sig.size = serialize_script_multisig(
coin, &(txinput->multisig), sighash, txinput->script_sig.bytes);
if (txinput->script_sig.size == 0) {
fsm_sendFailure(FailureType_Failure_ProcessError,
_("Failed to serialize multisig script"));
signing_abort();
return false;
}
} else { // SPENDADDRESS
txinput->script_sig.size = serialize_script_sig(
resp.serialized.signature.bytes, resp.serialized.signature.size,
public_key, 33, sighash, txinput->script_sig.bytes);
}
return true;
}
static bool signing_sign_input(void) {
uint8_t hash[32];
hasher_Final(&hasher_check, hash);
if (memcmp(hash, hash_outputs, 32) != 0) {
fsm_sendFailure(FailureType_Failure_DataError,
_("Transaction has changed during signing"));
signing_abort();
return false;
}
uint32_t hash_type = signing_hash_type();
hasher_Update(&ti.hasher, (const uint8_t *)&hash_type, 4);
tx_hash_final(&ti, hash, false);
resp.has_serialized = true;
if (!signing_sign_hash(&input, privkey, pubkey, hash)) return false;
resp.serialized.serialized_tx.size =
tx_serialize_input(&to, &input, resp.serialized.serialized_tx.bytes);
return true;
}
static bool signing_sign_segwit_input(TxInputType *txinput) {
// idx1: index to sign
uint8_t hash[32];
if (txinput->script_type == InputScriptType_SPENDWITNESS ||
txinput->script_type == InputScriptType_SPENDP2SHWITNESS) {
if (!compile_input_script_sig(txinput)) {
fsm_sendFailure(FailureType_Failure_ProcessError,
_("Failed to compile input"));
signing_abort();
return false;
}
if (txinput->amount > authorized_amount) {
fsm_sendFailure(FailureType_Failure_DataError,
_("Transaction has changed during signing"));
signing_abort();
return false;
}
authorized_amount -= txinput->amount;
signing_hash_bip143(txinput, hash);
resp.has_serialized = true;
if (!signing_sign_hash(txinput, node.private_key, node.public_key, hash))
return false;
uint8_t sighash = signing_hash_type() & 0xff;
if (txinput->has_multisig) {
uint32_t r = 1; // skip number of items (filled in later)
resp.serialized.serialized_tx.bytes[r] = 0;
r++;
int nwitnesses = 2;
for (uint32_t i = 0; i < txinput->multisig.signatures_count; i++) {
if (txinput->multisig.signatures[i].size == 0) {
continue;
}
nwitnesses++;
txinput->multisig.signatures[i]
.bytes[txinput->multisig.signatures[i].size] = sighash;
r += tx_serialize_script(txinput->multisig.signatures[i].size + 1,
txinput->multisig.signatures[i].bytes,
resp.serialized.serialized_tx.bytes + r);
}
uint32_t script_len =
compile_script_multisig(coin, &txinput->multisig, 0);
r += ser_length(script_len, resp.serialized.serialized_tx.bytes + r);
r += compile_script_multisig(coin, &txinput->multisig,
resp.serialized.serialized_tx.bytes + r);
resp.serialized.serialized_tx.bytes[0] = nwitnesses;
resp.serialized.serialized_tx.size = r;
} else { // single signature
uint32_t r = 0;
r += ser_length(2, resp.serialized.serialized_tx.bytes + r);
resp.serialized.signature.bytes[resp.serialized.signature.size] = sighash;
r += tx_serialize_script(resp.serialized.signature.size + 1,
resp.serialized.signature.bytes,
resp.serialized.serialized_tx.bytes + r);
r += tx_serialize_script(33, node.public_key,
resp.serialized.serialized_tx.bytes + r);
resp.serialized.serialized_tx.size = r;
}
} else {
// empty witness
resp.has_serialized = true;
resp.serialized.has_signature_index = false;
resp.serialized.has_signature = false;
resp.serialized.has_serialized_tx = true;
resp.serialized.serialized_tx.bytes[0] = 0;
resp.serialized.serialized_tx.size = 1;
}
// if last witness add tx footer
if (idx1 == inputs_count - 1) {
uint32_t r = resp.serialized.serialized_tx.size;
r += tx_serialize_footer(&to, resp.serialized.serialized_tx.bytes + r);
resp.serialized.serialized_tx.size = r;
}
return true;
}
static bool signing_sign_decred_input(TxInputType *txinput) {