Is there an import/export transaction patch?

[DeathAndTaxes]

Sort of.
But you don't really need to "Make offline payment"
You just do a traditional payment, but since the client is disconnected from the network you need to transfer its content by other means, not via a network.
And then "Publish offline payment" - sound like a catchy term

Just a thought.  Someone could make a public website for posting text based offline transactions.  Kinda a transaction "drop box".  The website would have bitcoind running and would import transactions and broadcast them to the rest of the bitcoind network.

So you make an offline transaction, save it as a text string to usb drive and then can copy & paste it into a website from any computer connected to internet.

[1715278084]

1715278084

[terrytibbs]

Can we get this rebased for the Qt codebase?

[piotr_n]

I have it ported into 0.4.0, but havent tried the qt version yet.

The patch is quite simple - any developer should be able to deal with it.

[etotheipi]

Thanks - I'll try that

Or maybe I won't... :|

I know exactly which 20 bytes you mean, I could probably handle some simple crypto myslef, but my god... version concatenated with the RIPEMD SHA256 of it, then concatenated with 4 bytes of SHA256 of SHA256 of the RIPEMD stuff... just so it could finally be base58 encoded....  

It couldn't be more complicated, could it?

Though, I guess some test vectors with intermediate steps would help me a lot

This is exactly why I made the following charts:
    https://bitcointalk.org/index.php?topic=29416.0

The address construction process is illustrated at the bottom.  Tx-serialization at the top.  And when you're finally an expert at those, you can take a shot at OP_CHECKSIG (don't forget to reverse endian before signing!).  Yeah, this stuff is complicated, but it's really a one-time investment.  I printed out a couple of these diagrams and keep them nearby when coding...