Merge pull request #1738 from jkczyz/2022-09-invoice-request
[rust-lightning] / lightning / src / chain / keysinterface.rs
index e3108fd54daa9c5a773cf0acfa85611c3c5fd787..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};
@@ -161,7 +163,7 @@ pub enum SpendableOutputDescriptor {
        ///
        /// To derive the revocation_pubkey provided here (which is used in the witness
        /// script generation), you must pass the counterparty revocation_basepoint (which appears in the
-       /// call to Sign::ready_channel) and the provided per_commitment point
+       /// call to Sign::provide_channel_parameters) and the provided per_commitment point
        /// to chan_utils::derive_public_revocation_key.
        ///
        /// The witness script which is hashed and included in the output script_pubkey may be
@@ -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.
        ///
@@ -352,7 +367,7 @@ pub trait BaseSign {
        /// Computes the signature for a commitment transaction's anchor output used as an
        /// input within `anchor_tx`, which spends the commitment transaction, at index `input`.
        fn sign_holder_anchor_input(
-               &self, anchor_tx: &mut Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
+               &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
        ) -> Result<Signature, ()>;
 
        /// Signs a channel announcement message with our funding key and our node secret key (aka
@@ -368,24 +383,22 @@ pub trait BaseSign {
                -> Result<(Signature, Signature), ()>;
 
        /// Set the counterparty static channel data, including basepoints,
-       /// counterparty_selected/holder_selected_contest_delay and funding outpoint.
-       /// This is done as soon as the funding outpoint is known.  Since these are static channel data,
-       /// they MUST NOT be allowed to change to different values once set.
+       /// counterparty_selected/holder_selected_contest_delay and funding outpoint. Since these are
+       /// static channel data, they MUST NOT be allowed to change to different values once set, as LDK
+       /// may call this method more than once.
        ///
        /// channel_parameters.is_populated() MUST be true.
-       ///
-       /// We bind holder_selected_contest_delay late here for API convenience.
-       ///
-       /// Will be called before any signatures are applied.
-       fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters);
+       fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
 }
 
-/// A cloneable signer.
+/// A writeable signer.
 ///
-/// Although we require signers to be cloneable, it may be useful for developers to be able to use
-/// signers in an un-sized way, for example as `dyn BaseSign`. Therefore we separate the Clone trait,
-/// which implies Sized, into this derived trait.
-pub trait Sign: BaseSign + Writeable + Clone {
+/// There will always be two instances of a signer per channel, one occupied by the
+/// [`ChannelManager`] and another by the channel's [`ChannelMonitor`].
+///
+/// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+/// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
+pub trait Sign: BaseSign + Writeable {
 }
 
 /// Specifies the recipient of an invoice, to indicate to [`KeysInterface::sign_invoice`] what node
@@ -402,7 +415,7 @@ pub enum Recipient {
 
 /// A trait to describe an object which can get user secrets and key material.
 pub trait KeysInterface {
-       /// A type which implements Sign which will be returned by get_channel_signer.
+       /// A type which implements Sign which will be returned by derive_channel_signer.
        type Signer : Sign;
 
        /// Get node secret key based on the provided [`Recipient`].
@@ -445,11 +458,20 @@ pub trait KeysInterface {
        /// This method should return a different value each time it is called, to avoid linking
        /// on-chain funds across channels as controlled to the same user.
        fn get_shutdown_scriptpubkey(&self) -> ShutdownScript;
-       /// Get a new set of Sign for per-channel secrets. These MUST be unique even if you
-       /// restarted with some stale data!
+       /// Generates a unique `channel_keys_id` that can be used to obtain a `Signer` through
+       /// [`KeysInterface::derive_channel_signer`]. The `user_channel_id` is provided to allow
+       /// implementations of `KeysInterface` to maintain a mapping between it and the generated
+       /// `channel_keys_id`.
        ///
        /// This method must return a different value each time it is called.
-       fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer;
+       fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32];
+       /// Derives the private key material backing a `Signer`.
+       ///
+       /// To derive a new `Signer`, a fresh `channel_keys_id` should be obtained through
+       /// [`KeysInterface::generate_channel_keys_id`]. Otherwise, an existing `Signer` can be
+       /// re-derived from its `channel_keys_id`, which can be obtained through its trait method
+       /// [`BaseSign::channel_keys_id`].
+       fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer;
        /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting
        /// onion packets and for temporary channel IDs. There is no requirement that these be
        /// persisted anywhere, though they must be unique across restarts.
@@ -463,6 +485,9 @@ pub trait KeysInterface {
        /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
        /// contain no versioning scheme. You may wish to include your own version prefix and ensure
        /// you've read all of the provided bytes to ensure no corruption occurred.
+       ///
+       /// This method is slowly being phased out -- it will only be called when reading objects
+       /// written by LDK versions prior to 0.0.113.
        fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
 
        /// Sign an invoice.
@@ -533,7 +558,8 @@ impl InMemorySigner {
                htlc_base_key: SecretKey,
                commitment_seed: [u8; 32],
                channel_value_satoshis: u64,
-               channel_keys_id: [u8; 32]) -> InMemorySigner {
+               channel_keys_id: [u8; 32],
+       ) -> InMemorySigner {
                let holder_channel_pubkeys =
                        InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
                                                             &payment_key, &delayed_payment_base_key,
@@ -570,39 +596,39 @@ impl InMemorySigner {
        }
 
        /// Counterparty pubkeys.
-       /// Will panic if ready_channel wasn't called.
+       /// Will panic if provide_channel_parameters wasn't called.
        pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
 
        /// The contest_delay value specified by our counterparty and applied on holder-broadcastable
        /// transactions, ie the amount of time that we have to wait to recover our funds if we
        /// broadcast a transaction.
-       /// Will panic if ready_channel wasn't called.
+       /// Will panic if provide_channel_parameters wasn't called.
        pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
 
        /// The contest_delay value specified by us and applied on transactions broadcastable
        /// by our counterparty, ie the amount of time that they have to wait to recover their funds
        /// if they broadcast a transaction.
-       /// Will panic if ready_channel wasn't called.
+       /// Will panic if provide_channel_parameters wasn't called.
        pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
 
        /// Whether the holder is the initiator
-       /// Will panic if ready_channel wasn't called.
+       /// Will panic if provide_channel_parameters wasn't called.
        pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
 
        /// Funding outpoint
-       /// Will panic if ready_channel wasn't called.
+       /// Will panic if provide_channel_parameters wasn't called.
        pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
 
        /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or
        /// building transactions.
        ///
-       /// Will panic if ready_channel wasn't called.
+       /// Will panic if provide_channel_parameters wasn't called.
        pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
                self.channel_parameters.as_ref().unwrap()
        }
 
        /// Whether anchors should be used.
-       /// Will panic if ready_channel wasn't called.
+       /// Will panic if provide_channel_parameters wasn't called.
        pub fn opt_anchors(&self) -> bool {
                self.get_channel_parameters().opt_anchors.is_some()
        }
@@ -654,8 +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()[..]);
@@ -671,7 +696,6 @@ impl InMemorySigner {
                witness.push(witness_script.clone().into_bytes());
                Ok(witness)
        }
-
 }
 
 impl BaseSign for InMemorySigner {
@@ -704,11 +728,12 @@ impl BaseSign for InMemorySigner {
 
                let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
                for htlc in commitment_tx.htlcs() {
-                       let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, self.opt_anchors(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+                       let channel_parameters = self.get_channel_parameters();
+                       let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, self.opt_anchors(), channel_parameters.opt_non_zero_fee_anchors.is_some(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
                        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));
                }
 
@@ -741,11 +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);
@@ -754,12 +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);
@@ -767,20 +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, ()> {
@@ -790,7 +828,7 @@ impl BaseSign for InMemorySigner {
        }
 
        fn sign_holder_anchor_input(
-               &self, anchor_tx: &mut Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
+               &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
        ) -> Result<Signature, ()> {
                let witness_script = chan_utils::get_anchor_redeemscript(&self.holder_channel_pubkeys.funding_pubkey);
                let sighash = sighash::SighashCache::new(&*anchor_tx).segwit_signature_hash(
@@ -805,8 +843,12 @@ impl BaseSign for InMemorySigner {
                Ok((sign(secp_ctx, &msghash, &self.node_secret), sign(secp_ctx, &msghash, &self.funding_key)))
        }
 
-       fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) {
-               assert!(self.channel_parameters.is_none(), "Acceptance already noted");
+       fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters) {
+               assert!(self.channel_parameters.is_none() || self.channel_parameters.as_ref().unwrap() == channel_parameters);
+               if self.channel_parameters.is_some() {
+                       // The channel parameters were already set and they match, return early.
+                       return;
+               }
                assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
                self.channel_parameters = Some(channel_parameters.clone());
        }
@@ -953,8 +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 {
@@ -985,13 +1027,8 @@ impl KeysManager {
                }
        }
        /// Derive an old Sign containing per-channel secrets based on a key derivation parameters.
-       ///
-       /// Key derivation parameters are accessible through a per-channel secrets
-       /// Sign::channel_keys_id and is provided inside DynamicOuputP2WSH in case of
-       /// onchain output detection for which a corresponding delayed_payment_key must be derived.
        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]);
-               assert!(chan_id <= core::u32::MAX as u64); // Otherwise the params field wasn't created by us
+               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);
@@ -1035,7 +1072,7 @@ impl KeysManager {
                        htlc_base_key,
                        commitment_seed,
                        channel_value_satoshis,
-                       params.clone()
+                       params.clone(),
                )
        }
 
@@ -1207,14 +1244,19 @@ impl KeysInterface for KeysManager {
                ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone())
        }
 
-       fn get_channel_signer(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
-               let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
-               assert!(child_ix <= core::u32::MAX as usize);
+       fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
+               let child_idx = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
+               assert!(child_idx <= core::u32::MAX as usize);
                let mut id = [0; 32];
-               id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
-               id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
-               id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
-               self.derive_channel_keys(channel_value_satoshis, &id)
+               id[0..4].copy_from_slice(&(child_idx as u32).to_be_bytes());
+               id[4..8].copy_from_slice(&self.starting_time_nanos.to_be_bytes());
+               id[8..16].copy_from_slice(&self.starting_time_secs.to_be_bytes());
+               id[16..32].copy_from_slice(&user_channel_id.to_be_bytes());
+               id
+       }
+
+       fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
+               self.derive_channel_keys(channel_value_satoshis, &channel_keys_id)
        }
 
        fn get_secure_random_bytes(&self) -> [u8; 32] {
@@ -1307,8 +1349,12 @@ impl KeysInterface for PhantomKeysManager {
                self.inner.get_shutdown_scriptpubkey()
        }
 
-       fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
-               self.inner.get_channel_signer(inbound, channel_value_satoshis)
+       fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
+               self.inner.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id)
+       }
+
+       fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
+               self.inner.derive_channel_signer(channel_value_satoshis, channel_keys_id)
        }
 
        fn get_secure_random_bytes(&self) -> [u8; 32] {