Wallet Import Format

[TT]

I got it!!!!

I ended up adding a bunch of tracers into the satoshi client to give me hex dumps of stuff so I would have some concrete examples to work with.

Thanks for all the help. I'm sure I'll have other issues later on, though

[TT]

In case anyone's interested in the hex dump of the data to be hashed in the above example, it's

0100000001fbe470cf995c04ecaa82fc2d4ae598075e21986700b544f660ffea93a6a82fe501000 0001976a914211f0c809a1a14f46af53ae59aa32d02aaf7272488acffffffff0180969800000000 001976a9148073e789954e05c5938c5cc493308f9021539bb588ac0000000001000000

[hashman]

Thanks for your work here !

I'm still waiting for somebody to put together a nice RFC to describe these things..   does that seem a possibility for the future? 

[TT]

Man, it's so frickin' hard to find good OpenSSL library documentation...

It's a little frustrating.

Would anyone happen to know how to create an ECDSA key using only the 32-byte private key format rather than the 279 byte DER format?

For the 279 byte DER format, I know you can do something like:

EC_KEY* pKey;
d2i_ECPrivateKey(&pKey, &privateKey, privateKeyLength);

But this only seems to work for the 279 byte DER form for the private key.

I'd like to know what sequence of calls to the OpenSSL library to use to get the full 279 byte DER private key  from a 32-byte private key...as, for instance, https://bitcointools.appspot.com/ can do.

Thanks.

-TT

[TT]

Ah, I got it!

It's all in the key.h source that's part of the satoshi client.
https://github.com/bitcoin/bitcoin/blob/master/src/key.h

CKey::GetPrivKey and CKey::SetPrivKey are accessor methods for the 279-byte DES private key.
CKey::GetSecret and CKey::SetSecret are accessor methods for the 32-byte private key.

Those of you who are interested in the OpenSSL calls needed, it's all spelled out in key.h

-TT

[casascius]

Would anyone happen to know how to create an ECDSA key using only the 32-byte private key format rather than the 279 byte DER format?

Sure, just pick a random 32-byte number.

Nearly all 32-byte numbers are valid private keys.  The ones that aren't valid as private keys all start with a large number (at least forty-eight) of zero bits, or a large number of one bits, all in a row.  At random, the likelihood of hitting them is so low as to be ignorable.