The current interface, if given a tweak, uses a *different secret key*
and tweaks it. This was an early experiment: we will switch to using
a secret tweak for invoice_requests like we do for invoice path ids.
To make sure there's no funny business, *hsmd* hashes to form the
tweak (i.e. no zero tweaks!).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Apparently VLS actually does something when we preapprove: if caller is just
checking we want to tell it not to do that!
I put in a flag so we can test both old and new APIs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This should make VLS's life easier: they can ignore dev flags they
don't understand, but we will know their capabilites after init and so
know what they didn't understand (if required).
The only flag for now is a flag to force failure for "preapprove" calls.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Before this it was channeld doing it, which was tied to a particular
channel. Create an API for lightningd to sign for any channel.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Added: hsmd: Added hsmd_forget_channel to enable explicit channel deletion. ([#6987])
Motivation: Previously, a signer prematurely forgetting a channel led
to failures in unresolved channel requests. This update introduces
hsmd_forget_channel, allowing nodes to explicitly notify signers when
a channel is irrevocably resolved and can be safely forgotten. This
ensures synchronized channel cleanup between nodes and signers.
This change maintains backward and forward compatibility. Nodes
explicitly check whether a signer has `WIRE_HSMD_FORGET_CHANNEL`
capability before sending the message. Nodes without
`WIRE_HSMD_FORGET_CHANNEL` capability won't send this message. Signers
capable of handling this message but not receiving it will continue to
use conservative pruning methods.
Fixes#6987
In general, a validating signer may be under a different operational
environment than the node, and therefore may have a different
source of on-chain data. The signer may therefore temporarily disagree
on whether a funding or splice transaction is locked (buried).
We would like to ensure agreement between the signer and the
node on how to progress a channel's state.
The following message are added to provide a solution:
- `check_outpoint(outpoint) -> bool` - check if the signer agrees that a funding candidate outpoint is buried
- `lock_outpoint(outpoint)` - change the funding/splice state to locked
Link: https://github.com/ElementsProject/lightning/issues/6722
Suggested-by: @devrandom
Co-Developed-by: Ken Sedgwick <ken@bonsai.com>
Changelog-Added: hsmd protocol: Added hsmd_check_outpoint and hsmd_lock_outpoint
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Originally VLS used hsmd_ready_channel as an early call during channel
setup, but later the BOLT-2 spec changed the name of funding_locked to channel_ready.
This is very confusing because the hsmd_ready_channel is not directly
related to the new channel_ready.
This commit is renaming the hsmd_ready_channel to hsmd_setup_channel.
Link: https://github.com/ElementsProject/lightning/issues/6717
Suggested-by: Ken Sedgwick
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
I obviously like the word "capabilities" since I reused it to refer
to the HSM's overall features :(
Suggested-by: @ksedgwic
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Since HTLC txs when using anchors are
SIGHASH_SINGLE|SIGHASH_ANYONECANPAY, we can attach other inputs to
give it a higher feerate. But we need the HSMd to actually sign the
combo.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We previously used WIRE_HSMD_SIGN_DELAYED_PAYMENT_TO_US,
WIRE_HSMD_SIGN_REMOTE_HTLC_TO_US, WIRE_HSMD_SIGN_PENALTY_TO_US and
WIRE_HSMD_SIGN_LOCAL_HTLC_TX which allow onchaind to sign txs,
but only for its specific channel.
We now want lightningd to sign these, but it's not bound to a specific
channel. So let's add variants that don't require that.
We are also now explicit about *what input* to sign. It's always zero
for now, but future combinations may change that.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Importantly, adds the version number at the *front* to help future
parsing.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Header from folded patch 'fix-hsm-check-pubkey.patch':
fixup! hsmd: capability addition: ability to check pubkeys.
We had a scheme where lightningd itself would put a per-node secret in
the blinded path, then we'd tell the caller when it was used. Then it
simply checks the alias to determine if the correct path was used.
But this doesn't work when we start to offer multiple blinded paths.
So go for a far simpler scheme, where the secret is generated (and
stored) by the caller, and hand it back to them.
We keep the split "with secret" or "without secret" API, since I'm
sure callers who don't care about the secret won't check that it
doesn't exist! And without that, someone can use a blinded path for a
different message and get a response which may reveal the node.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is the one place where we hand point32 over the wire internally, so
remove it.
This is also our first hsm version change!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With the rise of external HSMs like VLS, this is no longer an
internal-only API. Fortunately, it doesn't change very fast so
maintenance should not be a huge burden.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We put this in reply paths, so we can tell if they are used. This lets us
avoid responding unless the correct reply path is used.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Invoices are signed with our own key, but we use a transient payer_key with a
tweak for invoice_requests (and refunds).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Note that other directories were explicitly depending on the generated
file, instead of relying on their (already existing) dependency on
$(LIGHTNINGD_HSM_CLIENT_OBJS), so we remove that.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
