> Chaining a custom cert onto the end doesn't work, at least not if your
> "end" is the SSL cert. Chaining it to the SSL cert defeats the OP's
> intention of "cold signing", as the SSL private key is usually kept
> online, therefore can't be used to sign a pubkey that is supposed to
> stay offline.


What you wrote doesn't make any sense to me, sorry.

Yes, SSL private keys are kept online. That's irrelevant - the goal of all
this is not to protect against web server compromise. That's a pointless
goal to try and solve right now, because the SSL PKI cannot handle
compromised web servers and so neither can we (with v1 of the payments
spec).

The goal of this is to allow delegation of signing authority without giving
the delegate the SSL private key.