AaronFiore/electrum
1
0
Fork 0
Code Activity

Add signature Low R grinding to match with Bitcoin Core

Browse Source 
Ref: https://github.com/bitcoin/bitcoin/pull/13666

Depends on python-ecdsa pull request to allow for extra_entropy
Ref: https://github.com/warner/python-ecdsa/pull/92
This commit is contained in:
junderw
2018-08-23 09:27:08 +02:00
committed by SomberNight
parent 428b63822b
commit d16fd2783c
1 changed files with 9 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
electrum/ecc.py
View File

@@ -414,7 +414,15 @@ class ECPrivkey(ECPubkey):
if sigdecode is None:
sigdecode = get_r_and_s_from_sig_string
private_key = _MySigningKey.from_secret_exponent(self.secret_scalar, curve=SECP256k1)
sig = private_key.sign_digest_deterministic(data, hashfunc=hashlib.sha256, sigencode=sigencode)
def sig_encode_r_s(r, s, order):
return r, s
r, s = private_key.sign_digest_deterministic(data, hashfunc=hashlib.sha256, sigencode=sig_encode_r_s)
counter = 0
while r >= 2**255: # grind for low R value https://github.com/bitcoin/bitcoin/pull/13666
counter += 1
extra_entropy = int.to_bytes(counter, 32, 'little')
r, s = private_key.sign_digest_deterministic(data, hashfunc=hashlib.sha256, sigencode=sig_encode_r_s, extra_entropy=extra_entropy)
sig = sigencode(r, s, CURVE_ORDER)
public_key = private_key.get_verifying_key()
if not public_key.verify_digest(sig, data, sigdecode=sigdecode):
raise Exception('Sanity check verifying our own signature failed.')