Signing a tx with two input addresses in two steps, is that possible?

[Kazimir]

Suppose I want to create a tx like this: (with A1, A2, B1, B2 being Bitcoin addresses)

Input = A1 (0.3 BTC) , A2 (0.2 BTC)

Output = B1 (0.1 BTC) , B2 (0.3995 BTC) , fee (0.0005 BTC)

Can I "partially sign" this transaction with A1's private key first, and then complete the signature with A2's private key, thus signing it in two separate steps? Or must the signing of such a transaction always occur in one single step?

[kjj]

signrawtransaction returns the intermediate result each time.  This is clearly demonstrated in Gavin's gist on the raw transaction API:

https://gist.github.com/gavinandresen/3966071

[DannyHamilton]

signrawtransaction returns the intermediate result each time.  This is clearly demonstrated in Gavin's gist on the raw transaction API:

https://gist.github.com/gavinandresen/3966071

In other words:

Can I "partially sign" this transaction with A1's private key first, and then complete the signature with A2's private key, thus signing it in two separate steps?

Yes.

Or must the signing of such a transaction always occur in one single step?

No.

[scintill]

See this thread for how to do it with the raw transactions API.