core-lightning/common/keyset.c
Rusty Russell dd2773dfc0 common/keyset: use struct basepoints rather than open-coding fields.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2018-07-24 00:40:01 +02:00

68 lines
2.0 KiB
C

#include <common/derive_basepoints.h>
#include <common/key_derive.h>
#include <common/keyset.h>
bool derive_keyset(const struct pubkey *per_commitment_point,
const struct basepoints *self,
const struct basepoints *other,
struct keyset *keyset)
{
/* BOLT #3:
*
* ### `localpubkey`, `remotepubkey`, `local_htlcpubkey`,
* `remote_htlcpubkey`, `local_delayedpubkey`, and
* `remote_delayedpubkey` Derivation
*
* These pubkeys are simply generated by addition from their base points:
*
* pubkey = basepoint + SHA256(per_commitment_point || basepoint) * G
*
* The `localpubkey` uses the local node's `payment_basepoint`; the
* `remotepubkey` uses the remote node's `payment_basepoint`; the
* `local_delayedpubkey` uses the local node's
* `delayed_payment_basepoint`; the `local_htlcpubkey` uses the local
* node's `htlc_basepoint`; and the `remote_delayedpubkey` uses the
* remote node's `delayed_payment_basepoint`.
*/
if (!derive_simple_key(&self->payment,
per_commitment_point,
&keyset->self_payment_key))
return false;
if (!derive_simple_key(&other->payment,
per_commitment_point,
&keyset->other_payment_key))
return false;
if (!derive_simple_key(&self->htlc,
per_commitment_point,
&keyset->self_htlc_key))
return false;
if (!derive_simple_key(&other->htlc,
per_commitment_point,
&keyset->other_htlc_key))
return false;
if (!derive_simple_key(&self->delayed_payment,
per_commitment_point,
&keyset->self_delayed_payment_key))
return false;
/* BOLT #3:
*
* ### `revocationpubkey` Derivation
*
* The `revocationpubkey` is a blinded key: when the local node wishes
* to create a new commitment for the remote node, it uses its own
* `revocation_basepoint` and the remote node's `per_commitment_point`
* to derive a new `revocationpubkey` for the commitment.
*/
if (!derive_revocation_key(&other->revocation,
per_commitment_point,
&keyset->self_revocation_key))
return false;
return true;
}