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Date: Tue, 24 Jan 2012 18:33:33 +0100
From: =?UTF-8?B?QnJhdXRpZ2FtIFLDs2JlcnQ=?= <robert.brautigam@netmind.hu>
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To: Bitcoin Development <bitcoin-development@lists.sourceforge.net>
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Subject: Re: [Bitcoin-development] ECC Signature Issue
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On 01/23/2012 06:50 PM, Mike Hearn wrote:
>> I double checked that the official (C++) client is indeed successful
>> here. Oddly enough the bitcoinj implementation also seems to fail to
>> verify this transaction, which seems to point in the direction of
>> BouncyCastle (which we both use).
>
> BitCoinJ does not verify signatures (it is an SPV implementation), so
> I'm not sure what you mean by this. Are you using old code? There used
> to be some stuff that checked signatures but it was removed some time
> ago.

Hi Mike,

Bitcoinj has a class named ECKey. I just hardwired it with a main() to
check the mentioned transaction's signature.

I debugged the official client to get the exact data (hash, signed data
and public key). I checked signatures of transactions prior to the
mentioned one, all work, so the test code and the data I got are very
likely correct.

It might be that I'm using old bitcoinj code (I think it is 0.3, can't
find a version string anywhere), but I doubt that has any impact on the
ecc verification. Even if it did, I got my on code too, so what are the
odds that two implementations fail at the same point?

Anyway it would be helpful if someone just tried to run a verification
independently with the mentioned transaction (with BouncyCastle and with
openssl) and see whether he/she gets the same result.

I tried with BouncyCastle 140 and the newest 1.46, both fail.

Robert.