Merge pull request #1738 from jkczyz/2022-09-invoice-request
[rust-lightning] / lightning / src / chain / keysinterface.rs
index 104841b969ee2f827a35d09ec6f20df42aa973ae..f2d198bbfa101d97d129c251381a637a76aaf348 100644 (file)
@@ -31,10 +31,11 @@ use bitcoin::secp256k1::ecdh::SharedSecret;
 use bitcoin::secp256k1::ecdsa::RecoverableSignature;
 use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
 
-use crate::util::{byte_utils, transaction_utils};
+use crate::util::transaction_utils;
 use crate::util::crypto::{hkdf_extract_expand_twice, sign};
 use crate::util::ser::{Writeable, Writer, Readable, ReadableArgs};
-
+#[cfg(anchors)]
+use crate::util::events::HTLCDescriptor;
 use crate::chain::transaction::OutPoint;
 use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
 use crate::ln::{chan_utils, PaymentPreimage};
@@ -43,6 +44,7 @@ use crate::ln::msgs::UnsignedChannelAnnouncement;
 use crate::ln::script::ShutdownScript;
 
 use crate::prelude::*;
+use core::convert::TryInto;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use crate::io::{self, Error};
 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
@@ -324,6 +326,19 @@ pub trait BaseSign {
        /// (which is committed to in the BIP 143 signatures).
        fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
 
+       #[cfg(anchors)]
+       /// Computes the signature for a commitment transaction's HTLC output used as an input within
+       /// `htlc_tx`, which spends the commitment transaction, at index `input`. The signature returned
+       /// must be be computed using [`EcdsaSighashType::All`]. Note that this should only be used to
+       /// sign HTLC transactions from channels supporting anchor outputs after all additional
+       /// inputs/outputs have been added to the transaction.
+       ///
+       /// [`EcdsaSighashType::All`]: bitcoin::blockdata::transaction::EcdsaSighashType::All
+       fn sign_holder_htlc_transaction(
+               &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor,
+               secp_ctx: &Secp256k1<secp256k1::All>
+       ) -> Result<Signature, ()>;
+
        /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
        /// transaction, either offered or received.
        ///
@@ -665,8 +680,7 @@ impl InMemorySigner {
                if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
                if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { return Err(()); }
 
-               let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
-                       .expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
+               let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key);
                let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
                let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
                let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
@@ -682,7 +696,6 @@ impl InMemorySigner {
                witness.push(witness_script.clone().into_bytes());
                Ok(witness)
        }
-
 }
 
 impl BaseSign for InMemorySigner {
@@ -720,7 +733,7 @@ impl BaseSign for InMemorySigner {
                        let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
                        let htlc_sighashtype = if self.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
                        let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
-                       let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key).map_err(|_| ())?;
+                       let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key);
                        htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key));
                }
 
@@ -753,11 +766,11 @@ impl BaseSign for InMemorySigner {
        }
 
        fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
-               let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
+               let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
                let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
-               let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
+               let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
                let witness_script = {
-                       let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint).map_err(|_| ())?;
+                       let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint);
                        chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
                };
                let mut sighash_parts = sighash::SighashCache::new(justice_tx);
@@ -766,12 +779,12 @@ impl BaseSign for InMemorySigner {
        }
 
        fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
-               let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key).map_err(|_| ())?;
+               let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
                let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
-               let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint).map_err(|_| ())?;
+               let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
                let witness_script = {
-                       let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint).map_err(|_| ())?;
-                       let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint).map_err(|_| ())?;
+                       let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
+                       let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
                        chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
                };
                let mut sighash_parts = sighash::SighashCache::new(justice_tx);
@@ -779,20 +792,33 @@ impl BaseSign for InMemorySigner {
                return Ok(sign(secp_ctx, &sighash, &revocation_key))
        }
 
+       #[cfg(anchors)]
+       fn sign_holder_htlc_transaction(
+               &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor,
+               secp_ctx: &Secp256k1<secp256k1::All>
+       ) -> Result<Signature, ()> {
+               let per_commitment_point = self.get_per_commitment_point(
+                       htlc_descriptor.per_commitment_number, &secp_ctx
+               );
+               let witness_script = htlc_descriptor.witness_script(&per_commitment_point, secp_ctx);
+               let sighash = &sighash::SighashCache::new(&*htlc_tx).segwit_signature_hash(
+                       input, &witness_script, htlc_descriptor.htlc.amount_msat / 1000, EcdsaSighashType::All
+               ).map_err(|_| ())?;
+               let our_htlc_private_key = chan_utils::derive_private_key(
+                       &secp_ctx, &per_commitment_point, &self.htlc_base_key
+               );
+               Ok(sign(&secp_ctx, &hash_to_message!(sighash), &our_htlc_private_key))
+       }
+
        fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
-               if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) {
-                       let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) {
-                               if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) {
-                                       if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) {
-                                               chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey)
-                                       } else { return Err(()) }
-                               } else { return Err(()) }
-                       } else { return Err(()) };
-                       let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
-                       let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
-                       return Ok(sign(secp_ctx, &sighash, &htlc_key))
-               }
-               Err(())
+               let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key);
+               let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
+               let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
+               let htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
+               let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
+               let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
+               let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
+               Ok(sign(secp_ctx, &sighash, &htlc_key))
        }
 
        fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
@@ -969,8 +995,8 @@ impl KeysManager {
                                inbound_pmt_key_bytes.copy_from_slice(&inbound_payment_key[..]);
 
                                let mut rand_bytes_unique_start = Sha256::engine();
-                               rand_bytes_unique_start.input(&byte_utils::be64_to_array(starting_time_secs));
-                               rand_bytes_unique_start.input(&byte_utils::be32_to_array(starting_time_nanos));
+                               rand_bytes_unique_start.input(&starting_time_secs.to_be_bytes());
+                               rand_bytes_unique_start.input(&starting_time_nanos.to_be_bytes());
                                rand_bytes_unique_start.input(seed);
 
                                let mut res = KeysManager {
@@ -1002,7 +1028,7 @@ impl KeysManager {
        }
        /// Derive an old Sign containing per-channel secrets based on a key derivation parameters.
        pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
-               let chan_id = byte_utils::slice_to_be64(&params[0..8]);
+               let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap());
                let mut unique_start = Sha256::engine();
                unique_start.input(params);
                unique_start.input(&self.seed);