Add ChannelKeys to ChannelMonitor

[rust-lightning] / lightning / src / ln / chan_utils.rs

diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs
index a0cd3048f7e2dff07d8ba85fbfae20bd32782df5..e7bea90914ebf3fc834f909a84dc7c9bee84217f 100644 (file)
--- a/lightning/src/ln/chan_utils.rs
+++ b/lightning/src/ln/chan_utils.rs
@@ -18,7 +18,7 @@ use ln::channelmanager::{PaymentHash, PaymentPreimage};
 use ln::msgs::DecodeError;
 use util::ser::{Readable, Writeable, Writer, WriterWriteAdaptor};
 
-use secp256k1::key::{SecretKey,PublicKey};
+use secp256k1::key::{SecretKey, PublicKey};
 use secp256k1::{Secp256k1, Signature};
 use secp256k1;
 
@@ -137,24 +137,57 @@ pub(super) fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx:
 
 /// The set of public keys which are used in the creation of one commitment transaction.
 /// These are derived from the channel base keys and per-commitment data.
+#[derive(PartialEq)]
 pub struct TxCreationKeys {
        /// The per-commitment public key which was used to derive the other keys.
        pub per_commitment_point: PublicKey,
        /// The revocation key which is used to allow the owner of the commitment transaction to
        /// provide their counterparty the ability to punish them if they broadcast an old state.
-       pub revocation_key: PublicKey,
+       pub(crate) revocation_key: PublicKey,
        /// A's HTLC Key
-       pub a_htlc_key: PublicKey,
+       pub(crate) a_htlc_key: PublicKey,
        /// B's HTLC Key
-       pub b_htlc_key: PublicKey,
+       pub(crate) b_htlc_key: PublicKey,
        /// A's Payment Key (which isn't allowed to be spent from for some delay)
-       pub a_delayed_payment_key: PublicKey,
+       pub(crate) a_delayed_payment_key: PublicKey,
        /// B's Payment Key
-       pub b_payment_key: PublicKey,
+       pub(crate) b_payment_key: PublicKey,
 }
 
+/// One counterparty's public keys which do not change over the life of a channel.
+#[derive(Clone, PartialEq)]
+pub struct ChannelPublicKeys {
+       /// The public key which is used to sign all commitment transactions, as it appears in the
+       /// on-chain channel lock-in 2-of-2 multisig output.
+       pub funding_pubkey: PublicKey,
+       /// The base point which is used (with derive_public_revocation_key) to derive per-commitment
+       /// revocation keys. The per-commitment revocation private key is then revealed by the owner of
+       /// a commitment transaction so that their counterparty can claim all available funds if they
+       /// broadcast an old state.
+       pub revocation_basepoint: PublicKey,
+       /// The base point which is used (with derive_public_key) to derive a per-commitment payment
+       /// public key which receives immediately-spendable non-HTLC-encumbered funds.
+       pub payment_basepoint: PublicKey,
+       /// The base point which is used (with derive_public_key) to derive a per-commitment payment
+       /// public key which receives non-HTLC-encumbered funds which are only available for spending
+       /// after some delay (or can be claimed via the revocation path).
+       pub delayed_payment_basepoint: PublicKey,
+       /// The base point which is used (with derive_public_key) to derive a per-commitment public key
+       /// which is used to encumber HTLC-in-flight outputs.
+       pub htlc_basepoint: PublicKey,
+}
+
+impl_writeable!(ChannelPublicKeys, 33*5, {
+       funding_pubkey,
+       revocation_basepoint,
+       payment_basepoint,
+       delayed_payment_basepoint,
+       htlc_basepoint
+});
+
+
 impl TxCreationKeys {
-       pub(super) fn new<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, a_delayed_payment_base: &PublicKey, a_htlc_base: &PublicKey, b_revocation_base: &PublicKey, b_payment_base: &PublicKey, b_htlc_base: &PublicKey) -> Result<TxCreationKeys, secp256k1::Error> {
+       pub(crate) fn new<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, a_delayed_payment_base: &PublicKey, a_htlc_base: &PublicKey, b_revocation_base: &PublicKey, b_payment_base: &PublicKey, b_htlc_base: &PublicKey) -> Result<TxCreationKeys, secp256k1::Error> {
                Ok(TxCreationKeys {
                        per_commitment_point: per_commitment_point.clone(),
                        revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &b_revocation_base)?,
@@ -274,6 +307,22 @@ pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, keys: &TxCreationKey
        get_htlc_redeemscript_with_explicit_keys(htlc, &keys.a_htlc_key, &keys.b_htlc_key, &keys.revocation_key)
 }
 
+/// Gets the redeemscript for a funding output from the two funding public keys.
+/// Note that the order of funding public keys does not matter.
+pub fn make_funding_redeemscript(a: &PublicKey, b: &PublicKey) -> Script {
+       let our_funding_key = a.serialize();
+       let their_funding_key = b.serialize();
+
+       let builder = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2);
+       if our_funding_key[..] < their_funding_key[..] {
+               builder.push_slice(&our_funding_key)
+                       .push_slice(&their_funding_key)
+       } else {
+               builder.push_slice(&their_funding_key)
+                       .push_slice(&our_funding_key)
+       }.push_opcode(opcodes::all::OP_PUSHNUM_2).push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script()
+}
+
 /// panics if htlc.transaction_output_index.is_none()!
 pub fn build_htlc_transaction(prev_hash: &Sha256dHash, feerate_per_kw: u64, to_self_delay: u16, htlc: &HTLCOutputInCommitment, a_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
        let mut txins: Vec<TxIn> = Vec::new();