chainlib/cic_tools/eth/tx.py
2021-02-08 11:23:07 +01:00

84 lines
2.0 KiB
Python

# standard imports
import logging
# third-party imports
import sha3
from eth_keys import KeyAPI
from eth_keys.backends import NativeECCBackend
from rlp import decode as rlp_decode
from rlp import encode as rlp_encode
# local imports
from .address import to_checksum
logg = logging.getLogger(__name__)
field_debugs = [
'nonce',
'gasPrice',
'gas',
'to',
'value',
'data',
'v',
'r',
's',
]
def unpack_signed(tx_raw_bytes, chain_id=1):
d = rlp_decode(tx_raw_bytes)
logg.debug('decoding using chain id {}'.format(chain_id))
j = 0
for i in d:
logg.debug('decoded {}: {}'.format(field_debugs[j], i.hex()))
j += 1
vb = chain_id
if chain_id != 0:
v = int.from_bytes(d[6], 'big')
vb = v - (chain_id * 2) - 35
s = b''.join([d[7], d[8], bytes([vb])])
so = KeyAPI.Signature(signature_bytes=s)
h = sha3.keccak_256()
h.update(rlp_encode(d))
signed_hash = h.digest()
d[6] = chain_id
d[7] = b''
d[8] = b''
h = sha3.keccak_256()
h.update(rlp_encode(d))
unsigned_hash = h.digest()
p = so.recover_public_key_from_msg_hash(unsigned_hash)
a = p.to_checksum_address()
logg.debug('decoded recovery byte {}'.format(vb))
logg.debug('decoded address {}'.format(a))
logg.debug('decoded signed hash {}'.format(signed_hash.hex()))
logg.debug('decoded unsigned hash {}'.format(unsigned_hash.hex()))
to = d[3].hex() or None
if to != None:
to = to_checksum(to)
return {
'from': a,
'nonce': int.from_bytes(d[0], 'big'),
'gasPrice': int.from_bytes(d[1], 'big'),
'gas': int.from_bytes(d[2], 'big'),
'to': to,
'value': int.from_bytes(d[4], 'big'),
'data': '0x' + d[5].hex(),
'v': chain_id,
'r': '0x' + s[:32].hex(),
's': '0x' + s[32:64].hex(),
'chainId': chain_id,
'hash': '0x' + signed_hash.hex(),
'hash_unsigned': '0x' + unsigned_hash.hex(),
}