def preimage_hash(self, coin: CoinInfo, tx: SignTx, txi: TxInputType,
pubkeyhash: bytes, sighash: int) -> bytes:
h_preimage = HashWriter(
blake2b, b'', 32,
b'ZcashSigHash\x19\x1b\xa8\x5b') # BRANCH_ID = 0x5ba81b19
assert tx.overwintered
write_uint32(h_preimage,
tx.version | OVERWINTERED) # 1. nVersion | fOverwintered
write_uint32(h_preimage, coin.version_group_id) # 2. nVersionGroupId
write_bytes(h_preimage,
bytearray(self.get_prevouts_hash())) # 3. hashPrevouts
write_bytes(h_preimage,
bytearray(self.get_sequence_hash())) # 4. hashSequence
write_bytes(h_preimage,
bytearray(self.get_outputs_hash())) # 5. hashOutputs
write_bytes(h_preimage, b'\x00' * 32) # 6. hashJoinSplits
write_uint32(h_preimage, tx.lock_time) # 7. nLockTime
write_uint32(h_preimage, tx.expiry) # 8. expiryHeight
write_uint32(h_preimage, sighash) # 9. nHashType
write_bytes_rev(h_preimage, txi.prev_hash) # 10a. outpoint
write_uint32(h_preimage, txi.prev_index)
script_code = self.derive_script_code(txi,
pubkeyhash) # 10b. scriptCode
write_varint(h_preimage, len(script_code))
write_bytes(h_preimage, script_code)
write_uint64(h_preimage, txi.amount) # 10c. value
write_uint32(h_preimage, txi.sequence) # 10d. nSequence
return get_tx_hash(h_preimage)
def preimage_hash(
self,
coin: CoinInfo,
tx: SignTx,
txi: TxInputType,
pubkeyhash: bytes,
sighash: int,
) -> bytes:
h_preimage = HashWriter(sha256)
assert not tx.overwintered
write_uint32(h_preimage, tx.version) # nVersion
write_bytes(h_preimage,
bytearray(self.get_prevouts_hash(coin))) # hashPrevouts
write_bytes(h_preimage,
bytearray(self.get_sequence_hash(coin))) # hashSequence
write_bytes_rev(h_preimage, txi.prev_hash) # outpoint
write_uint32(h_preimage, txi.prev_index) # outpoint
script_code = self.derive_script_code(txi, pubkeyhash) # scriptCode
write_varint(h_preimage, len(script_code))
write_bytes(h_preimage, script_code)
write_uint64(h_preimage, txi.amount) # amount
write_uint32(h_preimage, txi.sequence) # nSequence
write_bytes(h_preimage,
bytearray(self.get_outputs_hash(coin))) # hashOutputs
write_uint32(h_preimage, tx.lock_time) # nLockTime
write_uint32(h_preimage, sighash) # nHashType
return get_tx_hash(h_preimage, double=coin.sign_hash_double)
def add_prevouts(self, txi: TxInputType):
write_bytes_rev(self.h_prevouts, txi.prev_hash)
write_uint32(self.h_prevouts, txi.prev_index)