Re: [Bitcoin-development] BIP 38 NFC normalisation issue

[Aaron Voisine <voisine@gmail.com>]

If the user creates a password on an iOS device with an astral
character and then can't enter that password on a JVM wallet, that
sucks. If JVMs really can't support unicode NFC then that's a strong
case to limit the spec to the subset of unicode that all popular
platforms can support, but it sounds like it might just be a JVM
string library bug that could hopefully be reported and fixed. I get
the same result as in the test case using apple's
CFStringNormalize(passphrase, kCFStringNormalizationFormC);

Aaron Voisine
breadwallet.com


On Tue, Jul 15, 2014 at 11:20 AM, Mike Hearn <mike@plan99.net> wrote:
> Yes, we know, Andreas' code is indeed doing normalisation.
>
> However it appears the output bytes end up being different. What I get back
> is:
>
> cf930001303430300166346139
>
> vs
>
> cf9300f0909080f09f92a9
>
> from the spec.
>
> I'm not sure why. It appears this is due to the character from the astral
> planes. Java is old and uses 16 bit characters internally - it wouldn't
> surprise me if there's some weirdness that means it doesn't/won't support
> this kind of thing.
>
> I recommend instead that any implementation that wishes to be compatible
> with JVM based wallets (I suspect Android is the same) just refuse any
> passphrase that includes characters outside the BMP. At least unless someone
> can find a fix. I somehow doubt this will really hurt anyone.
>
> ------------------------------------------------------------------------------
> Want fast and easy access to all the code in your enterprise? Index and
> search up to 200,000 lines of code with a free copy of Black Duck
> Code Sight - the same software that powers the world's largest code
> search on Ohloh, the Black Duck Open Hub! Try it now.
> http://p.sf.net/sfu/bds
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>