Rusty Russell [ARCHIVE] on Nostr: 📅 Original date posted:2018-12-17 📝 Original message:Johnson Lau <jl2012 at ...

📅 Original date posted:2018-12-17
📝 Original message:Johnson Lau <jl2012 at xbt.hk> writes:
> I don’t think this has been mentioned: without signing the script or masked script, OP_CODESEPARATOR becomes unusable or insecure with NOINPUT.
>
> In the new sighash proposal, we will sign the hash of the full script (or masked script), without any truncation. To make OP_CODESEPARATOR works like before, we will commit to the position of the last executed OP_CODESEPARATOR. If NOINPUT doesn’t commit to the masked script, it will just blindly committing to a random OP_CODESEPARATOR position, which a wallet couldn’t know what codes are actually being executed.

My anti-complexity argument leads me to ask why we'd support
OP_CODESEPARATOR at all? Though my argument is weaker here: no wallet
need support it.

But I don't see how OP_CODESEPARATOR changes anything here, wrt NOINPUT?
Remember, anyone can create an output which can be spent by any NOINPUT,
whether we go for OP_MASK or simply not commiting to the input script.

Confused,
Rusty.