Esta noche estuvo gmaxwell en el IRC. Os dejo un extracto de sus frases y alguna más de apoyo. Lo siento pero está en inglés, no puedo pararme a traducirlo.
[2014-02-07 05:06:11] < gmaxwell> I talked to him some a while back and offered support, an gave some
advice. It's my belief that the original issues are likely fixed now and there
is just a cluster-@#$@# of double spent transactions that needs to be sorted.
[2014-02-07 05:07:08] < gmaxwell> dizko: I believe they're all failing now because they're frequently
spending previously spent inputs not due to non-canonical signatures.
[2014-02-07 05:08:05] < gmaxwell> dizko: no, they had two original problems. One was that they were
spending immature coins, resulting in transactions which _couldn't_ be
confirmed for up to 100 blocks.
[2014-02-07 05:08:38] < gmaxwell> And their wallet tracking problems were such that this wasn't
trivially fixed.
[2014-02-07 05:09:05] < gmaxwell> the other was that they were producing signatures was invalid der
encodings (excessively padded) which the bitcoin nodes stopped relaying and
mining in 0.8+
[2014-02-07 05:09:22] < gmaxwell> dizko: there appears now to be a third issue
[2014-02-07 05:10:05] < gmaxwell> dizko: which is that if someone helpfully 'fixed' the R,S
non-canonication by removing the excess padding and the network confirmed the
transaction mtgox's software wouldn't notice and would attempt to spend the
same inputs in a future transaction.
[2014-02-07 05:11:53] < gmaxwell> dizko: the reason for this is that the 'fixed' transactions had a
different transaction ID and thus were ignored by their software.
[2014-02-07 05:14:17] < gmaxwell> dizko: in any case, as phantomcircuit pointed out here the
non-recognition of the mutated transactions may have caused doubled payments.
[2014-02-07 05:15:11] < gmaxwell> so now, I _imagine_, there is now a huge mess to sort out which of
the reissued transactions were really originally confirmed and thus mistakingly
refunded / reissued to the customer.
[2014-02-07 05:15:27] < gmaxwell> (e.g. and they may have been robbed a bit in the process)
[2014-02-07 05:18:42] < gmaxwell> modrobert: Yes. Or at least reissued and issued. E.g. they make a
payment to you that gets stuck, someone helpfully fixes the payment and helps
it go through, then mtgox notices the transaction is stuck— but doesn't notice
the fixed transaction because it has a different txid— and tries it again
using different inputs. Perhaps both go through.
[2014-02-07 05:19:17] < gmaxwell> Then you have the software thinking that the original coins the
first transaction spend were unspent, and it tries to use them on someone elses
transaction— and so that one gets stuck too.
[2014-02-07 05:20:39] < gmaxwell> This mostly stems from a minor design flaw in the Bitcoin protocol
that we've been slowly removing— that Bitcoin transactions can be mutated by
third parties to change their TXIDs— (it's difficult to remove since wallets
must change their signing behavior)... plus mtgox's custom wallet software
failing to handle the bad things that the design flaw results in.
[2014-02-07 05:21:24] < gmaxwell> modrobert: right but there are _other_ non-stuck transactions which
spent the coins that the stuck transactions were trying to spend. Sorry, it's a
bit difficult to explain this to you because you've likely been misinformed
about how Bitcoin works under the hood.
[2014-02-07 05:23:12] < gmaxwell> oakpacific: nah, the nature of the bug was that it would only be
eronious some percentage of the time. The problem was that they were making the
signatures fixed length (e.g. always 34 bytes or whatever) and sometimes the
numbers in the signature were smaller and so the signature should have been
smaller.
[2014-02-07 05:27:21] < gmaxwell> modrobert: so mtgox has some software problems due to not
accomidating a surprising design error in bitcoin, where they've lost track of
which coins of theirs are already spent or not, and they keep spending them
over again.
[2014-02-07 05:27:46] < gmaxwell> (the design error in bitcoin being that a third party can change
the txid of your own transactions)
[2014-02-07 05:28:18] < dizko> gmaxwell: shouldnt they just export their private keys and import them
into a working wallet? they can stop withdrawals for the weekend and come back
with clean outputs to spend
[2014-02-07 05:29:12] < gmaxwell> dizko: maybe they're doing that now, with their fantastic
communication skills you wouldn't know! :) they also have to make sure they
don't let anyone withdraw funds they already got.
[2014-02-07 05:29:48] < gmaxwell> dignork: https://en.bitcoin.it/wiki/Transaction_Malleability (I
haven't (recently) reviewd that page, so I can't vouch for its accuracy on the
details)
[2014-02-07 05:31:10] < gmaxwell> Magicaltux used to talk here a lot but I think he made problems for
himself in doing so. e.g. speaking prematurely or on speculation. It's
especially hard to communicate when you have to contend with regulators trying
to shut you down and lawsuits and such— anything you say could be prejudicial
to these interests.
[2014-02-07 05:32:44] < gmaxwell> I have gotten the impression that a lot of the gnarly core
technical stuff is being done by magicaltux personally and that he simply
doesn't have the bandwidth for that on top of the legal and regulatory matters,
especially at gox's current siz.e
[2014-02-07 05:32:45] < drenllateno> "gmaxwell (the design error in bitcoin being that a third party
can change the txid of your own transactions)" Can this be changed or fixed?
[2014-02-07 05:34:11] < gmaxwell> drenllateno: we're fixing it, but it will take years to fix
completely because all sigining software must be updated. The first concrete
step towards this was forbidding excessively padded transactions in bitcoin
0.8. Because mtgox was still producing these transactions some times this
contributed to their initial issues, highlighting how hard and dangerous fixing
this stuff is.
[…]
[2014-02-07 06:43:39] < gmaxwell> 20:29 < gmaxwell> dizko: maybe they're doing that now, with their
fantastic communication skills you wouldn't know! :) << There we go:
https://www.mtgox.com/press_release_20140207.html
