Files
app-ethereum/examples/signMessage.py
Clément Péron 51ac58fd37 examples: add sign message python example
Require Python3 and eth_keys

Signed-off-by: Clément Péron <peron.clem@gmail.com>
2019-03-26 14:31:59 +01:00

98 lines
2.9 KiB
Python
Executable File

#!/usr/bin/env python3
"""
*******************************************************************************
* Ledger Ethereum App
* (c) 2016-2019 Ledger
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
********************************************************************************
"""
from __future__ import print_function
from ledgerblue.comm import getDongle
from ledgerblue.commException import CommException
from decimal import Decimal
from ethBase import sha3
from eth_keys import KeyAPI
import argparse
import struct
import binascii
# Define here Chain_ID
CHAIN_ID = 0
# Magic define
SIGN_MAGIC = b'\x19Ethereum Signed Message:\n'
def parse_bip32_path(path):
if len(path) == 0:
return b""
result = b""
elements = path.split('/')
for pathElement in elements:
element = pathElement.split('\'')
if len(element) == 1:
result = result + struct.pack(">I", int(element[0]))
else:
result = result + struct.pack(">I", 0x80000000 | int(element[0]))
return result
parser = argparse.ArgumentParser()
parser.add_argument('--path', help="BIP 32 path to sign with")
parser.add_argument('--message', help="Message to sign", required=True)
args = parser.parse_args()
args.message = args.message.encode()
if args.path == None:
args.path = "44'/0'"
encodedTx = struct.pack(">I", len(args.message))
encodedTx += args.message
donglePath = parse_bip32_path(args.path)
apdu = bytearray.fromhex("e0080000")
apdu.append(len(donglePath) + 1 + len(encodedTx))
apdu.append(len(donglePath) // 4)
apdu += donglePath + encodedTx
dongle = getDongle(True)
result = dongle.exchange(bytes(apdu))
v = int(result[0])
# Compute parity
if (CHAIN_ID*2 + 35) + 1 > 255:
ecc_parity = v - ((CHAIN_ID*2 + 35) % 256)
else:
ecc_parity = (v + 1) % 2
v = "%02X" % ecc_parity
r = binascii.hexlify(result[1:1 + 32]).decode()
s = binascii.hexlify(result[1 + 32: 1 + 32 + 32]).decode()
msg_to_sign = SIGN_MAGIC + str(len(args.message)).encode() + args.message
hash = sha3(msg_to_sign.decode())
signature = KeyAPI.Signature(vrs=(int(v, 16), int(r, 16), int(s, 16)))
pubkey = KeyAPI.PublicKey.recover_from_msg_hash(hash, signature)
print("[INFO] Hash is: 0x", binascii.hexlify(hash).decode(), sep='');
print('{')
print(' "address": "', pubkey.to_address(), '",', sep='')
print(' "msg": "', args.message.decode(),'",', sep='')
print(' "sig": "', signature, '",', sep = '')
print(' "version": "3"')
print(' "signed": "ledger"')
print('}')