public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: Andreas Schildbach <andreas@schildbach.de>
To: bitcoin-development@lists.sourceforge.net
Subject: Re: [Bitcoin-development] BIP 38 NFC normalisation issue
Date: Tue, 15 Jul 2014 15:19:29 +0200	[thread overview]
Message-ID: <lq39p1$gff$1@ger.gmane.org> (raw)
In-Reply-To: <CAObn+gfbH61kyv_ttT4vsQuNFRWLB5H3xaux7GQ0co82ucO_eA@mail.gmail.com>

I think generally control-characters (such as \u0000) should be
disallowed in passphrases. (Even the use of whitespaces is very
questionable.)

I'm ok with allowing pile-of-poo's. On mobile phones there is keyboards
just containing emoticons -- why not allow those? Assuming NFC works of
course.


On 07/15/2014 03:07 PM, Eric Winer wrote:
> I don't know for sure if the test vector is correct NFC form.  But for
> what it's worth, the Pile of Poo character is pretty easily accessible
> on the iPhone and Android keyboards, and in this string it's already in
> NFC form (f09f92a9 in the test result).  I've certainly seen it in
> usernames around the internet, and wouldn't be surprised to see it in
> passphrases entered on smartphones, especially if the author of a
> BIP38-compatible app includes a (possibly ill-advised) suggestion to
> have your passphrase "include special characters".
> 
> I haven't seen the NULL character on any smartphone keyboards, though -
> I assume the iOS and Android developers had the foresight to know how
> much havoc that would wreak on systems assuming null-terminated strings.
>  It seems unlikely that NULL would be in a real-world passphrase entered
> by a sane user.
> 
> 
> On Tue, Jul 15, 2014 at 8:03 AM, Mike Hearn <mike@plan99.net
> <mailto:mike@plan99.net>> wrote:
> 
>     [+cc aaron]
> 
>     We recently added an implementation of BIP 38 (password protected
>     private keys) to bitcoinj. It came to my attention that the third
>     test vector may be broken. It gives a hex version of what the NFC
>     normalised version of the input string should be, but this does not
>     match the results of the Java unicode normaliser, and in fact I
>     can't even get Python to print the names of the characters past the
>     embedded null. I'm curious where this normalised version came from.
> 
>     Given that "pile of poo" is not a character I think any sane user
>     would put into a passphrase, I question the value of this test
>     vector. NFC form is intended to collapse things like umlaut control
>     characters onto their prior code point, but here we're feeding the
>     algorithm what is basically garbage so I'm not totally surprised
>     that different implementations appear to disagree on the outcome.
> 
>     Proposed action: we remove this test vector as it does not represent
>     any real world usage of the spec, or if we desperately need to
>     verify NFC normalisation I suggest using a different, more realistic
>     test string, like Zürich, or something written in Thai.
> 
> 
> 
>     Test 3:
> 
>       * Passphrase ϓ␀𐐀💩 (\u03D2\u0301\u0000\U00010400\U0001F4A9; GREEK
>         UPSILON WITH HOOK <http://codepoints.net/U+03D2>, COMBINING
>         ACUTE ACCENT <http://codepoints.net/U+0301>, NULL
>         <http://codepoints.net/U+0000>, DESERET CAPITAL LETTER LONG I
>         <http://codepoints.net/U+10400>, PILE OF POO
>         <http://codepoints.net/U+1F4A9>)
>       * Encrypted key:
>         6PRW5o9FLp4gJDDVqJQKJFTpMvdsSGJxMYHtHaQBF3ooa8mwD69bapcDQn
>       * Bitcoin Address: 16ktGzmfrurhbhi6JGqsMWf7TyqK9HNAeF
>       * Unencrypted private key (WIF):
>         5Jajm8eQ22H3pGWLEVCXyvND8dQZhiQhoLJNKjYXk9roUFTMSZ4
>       * /Note:/ The non-standard UTF-8 characters in this passphrase
>         should be NFC normalized to result in a passphrase
>         of0xcf9300f0909080f09f92a9 before further processing
> 
> 
> 
> 
>     ------------------------------------------------------------------------------
>     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
>     <mailto:Bitcoin-development@lists.sourceforge.net>
>     https://lists.sourceforge.net/lists/listinfo/bitcoin-development
> 
> 
> 
> 
> ------------------------------------------------------------------------------
> 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
> 





  reply	other threads:[~2014-07-15 13:19 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-15 12:03 [Bitcoin-development] BIP 38 NFC normalisation issue Mike Hearn
2014-07-15 13:07 ` Eric Winer
2014-07-15 13:19   ` Andreas Schildbach [this message]
2014-07-15 13:32     ` Michael Wozniak
2014-07-15 15:13   ` Brooks Boyd
2014-07-15 18:20     ` Mike Hearn
2014-07-15 22:23       ` Aaron Voisine
2014-07-16  9:12         ` Mike Hearn
2014-07-16  9:17         ` Andreas Schildbach
2014-07-16  9:29           ` Mike Hearn
2014-07-16 10:46             ` Andreas Schildbach
2014-07-16 11:04               ` Andreas Schildbach
2014-07-16 21:06                 ` Aaron Voisine
2014-07-16 22:02                   ` Andreas Schildbach
2014-07-16 22:22                     ` Andreas Schildbach
2014-07-17 10:59                     ` Mike Hearn
2014-07-17 11:27                       ` Andreas Schildbach
2014-07-16 12:38             ` Wladimir
2014-07-15 15:17   ` Jeff Garzik
2014-07-15 15:20     ` Mike Hearn
2014-07-15 15:32     ` Andreas Schildbach
2014-07-15 15:53       ` Jeff Garzik

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='lq39p1$gff$1@ger.gmane.org' \
    --to=andreas@schildbach.de \
    --cc=bitcoin-development@lists.sourceforge.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox