async def sign_tx(
ctx: wire.Context, msg: EosSignTx, keychain: seed.Keychain
) -> EosSignedTx:
if msg.chain_id is None:
raise wire.DataError("No chain id")
if msg.header is None:
raise wire.DataError("No header")
if msg.num_actions is None or msg.num_actions == 0:
raise wire.DataError("No actions")
await paths.validate_path(ctx, validate_full_path, keychain, msg.address_n, CURVE)
node = keychain.derive(msg.address_n)
sha = HashWriter(sha256())
await _init(ctx, sha, msg)
await _actions(ctx, sha, msg.num_actions)
writers.write_variant32(sha, 0)
writers.write_bytes(sha, bytearray(32))
digest = sha.get_digest()
signature = secp256k1.sign(
node.private_key(), digest, True, secp256k1.CANONICAL_SIG_EOS
)
return EosSignedTx(signature=base58_encode("SIG_", "K1", signature))
def _public_key_to_wif(pub_key: bytes) -> str:
if pub_key[0] == 0x04 and len(pub_key) == 65:
head = b"\x03" if pub_key[64] & 0x01 else b"\x02"
compressed_pub_key = head + pub_key[1:33]
elif pub_key[0] in [0x02, 0x03] and len(pub_key) == 33:
compressed_pub_key = pub_key
else:
raise wire.DataError("invalid public key")
return base58_encode("EOS", "", compressed_pub_key)