From 51ac58fd372627eeaa00e5b9f0706edf6e1c14fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20P=C3=A9ron?= <peron.clem@gmail.com>
Date: Mon, 25 Mar 2019 17:49:57 +0100
Subject: [PATCH] examples: add sign message python example
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Require Python3 and eth_keys

Signed-off-by: Clément Péron <peron.clem@gmail.com>
---
 examples/ethBase.py     |  8 ++--
 examples/signMessage.py | 97 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+), 5 deletions(-)
 create mode 100755 examples/signMessage.py

diff --git a/examples/ethBase.py b/examples/ethBase.py
index 95fb143..b66b116 100755
--- a/examples/ethBase.py
+++ b/examples/ethBase.py
@@ -23,14 +23,12 @@ from rlp import Serializable
 
 try:
     from Crypto.Hash import keccak
-
-    def sha3_256(x): return keccak.new(digest_bits=256, data=x).digest()
+    def sha3_256(x): return keccak.new(digest_bits=256, data=x.encode()).digest()
 except:
     import sha3 as _sha3
-
     def sha3_256(x): return _sha3.sha3_256(x).digest()
-address = Binary.fixed_length(20, allow_empty=True)
 
+address = Binary.fixed_length(20, allow_empty=True)
 
 def sha3(seed):
     return sha3_256(str(seed))
@@ -71,4 +69,4 @@ def unsigned_tx_from_tx(tx):
         to=tx.to,
         value=tx.value,
         data=tx.data,
-    )
\ No newline at end of file
+    )
diff --git a/examples/signMessage.py b/examples/signMessage.py
new file mode 100755
index 0000000..019d58a
--- /dev/null
+++ b/examples/signMessage.py
@@ -0,0 +1,97 @@
+#!/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('}')