Print Page - hashing the seed or hashing the hex-string representation of the seed?

I'm playing around with electrum 1.9.2

It seems that with seed_version=4 if I do

./electrum --offline --wallet=testwallet restore

and enter "ffff" as seed I will get different results than when entering "FFFF". Looking into the code it seems you are indeed hashing the string representation of that hex number:

account.py, class OldAccount

Code:

    def stretch_key(self,seed):
        oldseed = seed
        for i in range(100000):
            seed = hashlib.sha256(seed + oldseed).digest()
        return string_to_number( seed )

and seed is the hex string representation of the seed. I guess that cannot be chaned anymore without making it incompatible.

Now I looked into the new seed_version = 6 stuff with bip-32, I simply patched wallet.py to set self.seed_version=6 to trigger the new code paths and it still is hashing the string representation:

Code:

    def create_master_keys(self, account_type):
        master_k, master_c, master_K, master_cK = bip32_init(self.get_seed(None))
        [...]

    def get_seed(self, password):
        s = pw_decode(self.seed, password)
        if self.seed_version == 4:
            seed = s
        else:
            seed = mnemonic_hash(s)
        #todo:  #self.sequences[0].check_seed(seed)
        return seed

shouldn't this line be

Code:

        else:
            seed = mnemonic_hash(s.decode('hex'))

I changed it to see what happens and also inserted a few prints here and there to see whether its handling binary data or hex-strings and now it seems to work correctly and will produce the same keys for "ffff" and "FFFF".

with above patch and bip32 enabled I get the following addresses from "FFFF" or "ffff"

1JFGdf7FsmNZEsPWUZeCRqcKUZF4iTLKjk
1BbHtbsX4ajyb6vVrTtatrUiGMGUtZaVMX
1HjFdepBf9qg8BKmLtRf9iYBWa1YFRV2hp
1QHErKePKQurWELiJD2pTwaxEwZZPjMogX
16p6r7vyj8B2t6SbugYgoHQJhX8XkBpX4G
1Bhqh25w998MsxJjnEfAxPLvrjCi4zB7xF
13k5Zivs8Zw9QUfYcVbG3w8rHV3KjTR2Xk
19hVwRqH57FtFYKyZf2SsEsoEeFJ3aj2NH

and the argument to bip32_seed() is now 974e4be2c4f570e64ec86819bf8d14a66584481993b5e82d6400c78288025c5c40cd6e1d1218107 ee778174af562ceae7e4c31ff206f7cfe5708fb65ba4853f5

Please tell me that this is indeed a bug and not intentional

Bitcoin Forum

Bitcoin => Electrum => Topic started by: prof7bit on November 09, 2013, 08:20:25 PM