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

// This file is Copyright its original authors, visible in version control
// history.
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.

//! Various utilities for building scripts and deriving keys related to channels. These are
//! largely of interest for those implementing chain::keysinterface::ChannelKeys message signing
//! by hand.

use bitcoin::blockdata::script::{Script,Builder};
use bitcoin::blockdata::opcodes;
use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction, SigHashType};
use bitcoin::consensus::encode::{Decodable, Encodable};
use bitcoin::consensus::encode;
use bitcoin::util::bip143;

use bitcoin::hashes::{Hash, HashEngine};
use bitcoin::hashes::sha256::Hash as Sha256;
use bitcoin::hashes::ripemd160::Hash as Ripemd160;
use bitcoin::hash_types::{Txid, PubkeyHash};

use ln::channelmanager::{PaymentHash, PaymentPreimage};
use ln::msgs::DecodeError;
use util::ser::{Readable, Writeable, Writer, WriterWriteAdaptor};
use util::byte_utils;

use bitcoin::secp256k1::key::{SecretKey, PublicKey};
use bitcoin::secp256k1::{Secp256k1, Signature};
use bitcoin::secp256k1;

use std::{cmp, mem};

const MAX_ALLOC_SIZE: usize = 64*1024;

pub(super) const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
pub(super) const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;

#[derive(PartialEq)]
pub(crate) enum HTLCType {
        AcceptedHTLC,
        OfferedHTLC
}

impl HTLCType {
        /// Check if a given tx witnessScript len matchs one of a pre-signed HTLC
        pub(crate) fn scriptlen_to_htlctype(witness_script_len: usize) ->  Option<HTLCType> {
                if witness_script_len == 133 {
                        Some(HTLCType::OfferedHTLC)
                } else if witness_script_len >= 136 && witness_script_len <= 139 {
                        Some(HTLCType::AcceptedHTLC)
                } else {
                        None
                }
        }
}

// Various functions for key derivation and transaction creation for use within channels. Primarily
// used in Channel and ChannelMonitor.

/// Build the commitment secret from the seed and the commitment number
pub fn build_commitment_secret(commitment_seed: &[u8; 32], idx: u64) -> [u8; 32] {
        let mut res: [u8; 32] = commitment_seed.clone();
        for i in 0..48 {
                let bitpos = 47 - i;
                if idx & (1 << bitpos) == (1 << bitpos) {
                        res[bitpos / 8] ^= 1 << (bitpos & 7);
                        res = Sha256::hash(&res).into_inner();
                }
        }
        res
}

/// Implements the per-commitment secret storage scheme from
/// [BOLT 3](https://github.com/lightningnetwork/lightning-rfc/blob/dcbf8583976df087c79c3ce0b535311212e6812d/03-transactions.md#efficient-per-commitment-secret-storage).
///
/// Allows us to keep track of all of the revocation secrets of counterarties in just 50*32 bytes
/// or so.
#[derive(Clone)]
pub(super) struct CounterpartyCommitmentSecrets {
        old_secrets: [([u8; 32], u64); 49],
}

impl PartialEq for CounterpartyCommitmentSecrets {
        fn eq(&self, other: &Self) -> bool {
                for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
                        if secret != o_secret || idx != o_idx {
                                return false
                        }
                }
                true
        }
}

impl CounterpartyCommitmentSecrets {
        pub(super) fn new() -> Self {
                Self { old_secrets: [([0; 32], 1 << 48); 49], }
        }

        #[inline]
        fn place_secret(idx: u64) -> u8 {
                for i in 0..48 {
                        if idx & (1 << i) == (1 << i) {
                                return i
                        }
                }
                48
        }

        pub(super) fn get_min_seen_secret(&self) -> u64 {
                //TODO This can be optimized?
                let mut min = 1 << 48;
                for &(_, idx) in self.old_secrets.iter() {
                        if idx < min {
                                min = idx;
                        }
                }
                min
        }

        #[inline]
        pub(super) fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
                let mut res: [u8; 32] = secret;
                for i in 0..bits {
                        let bitpos = bits - 1 - i;
                        if idx & (1 << bitpos) == (1 << bitpos) {
                                res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
                                res = Sha256::hash(&res).into_inner();
                        }
                }
                res
        }

        pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> {
                let pos = Self::place_secret(idx);
                for i in 0..pos {
                        let (old_secret, old_idx) = self.old_secrets[i as usize];
                        if Self::derive_secret(secret, pos, old_idx) != old_secret {
                                return Err(());
                        }
                }
                if self.get_min_seen_secret() <= idx {
                        return Ok(());
                }
                self.old_secrets[pos as usize] = (secret, idx);
                Ok(())
        }

        /// Can only fail if idx is < get_min_seen_secret
        pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
                for i in 0..self.old_secrets.len() {
                        if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
                                return Some(Self::derive_secret(self.old_secrets[i].0, i as u8, idx))
                        }
                }
                assert!(idx < self.get_min_seen_secret());
                None
        }
}

impl Writeable for CounterpartyCommitmentSecrets {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
                for &(ref secret, ref idx) in self.old_secrets.iter() {
                        writer.write_all(secret)?;
                        writer.write_all(&byte_utils::be64_to_array(*idx))?;
                }
                Ok(())
        }
}
impl Readable for CounterpartyCommitmentSecrets {
        fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
                let mut old_secrets = [([0; 32], 1 << 48); 49];
                for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
                        *secret = Readable::read(reader)?;
                        *idx = Readable::read(reader)?;
                }

                Ok(Self { old_secrets })
        }
}

/// Derives a per-commitment-transaction private key (eg an htlc key or delayed_payment key)
/// from the base secret and the per_commitment_point.
///
/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
/// generated (ie our own).
pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> Result<SecretKey, secp256k1::Error> {
        let mut sha = Sha256::engine();
        sha.input(&per_commitment_point.serialize());
        sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize());
        let res = Sha256::from_engine(sha).into_inner();

        let mut key = base_secret.clone();
        key.add_assign(&res)?;
        Ok(key)
}

/// Derives a per-commitment-transaction public key (eg an htlc key or a delayed_payment key)
/// from the base point and the per_commitment_key. This is the public equivalent of
/// derive_private_key - using only public keys to derive a public key instead of private keys.
///
/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
/// generated (ie our own).
pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> Result<PublicKey, secp256k1::Error> {
        let mut sha = Sha256::engine();
        sha.input(&per_commitment_point.serialize());
        sha.input(&base_point.serialize());
        let res = Sha256::from_engine(sha).into_inner();

        let hashkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&res)?);
        base_point.combine(&hashkey)
}

/// Derives a per-commitment-transaction revocation key from its constituent parts.
///
/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
/// generated (ie our own).
pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_secret: &SecretKey, revocation_base_secret: &SecretKey) -> Result<SecretKey, secp256k1::Error> {
        let revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &revocation_base_secret);
        let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);

        let rev_append_commit_hash_key = {
                let mut sha = Sha256::engine();
                sha.input(&revocation_base_point.serialize());
                sha.input(&per_commitment_point.serialize());

                Sha256::from_engine(sha).into_inner()
        };
        let commit_append_rev_hash_key = {
                let mut sha = Sha256::engine();
                sha.input(&per_commitment_point.serialize());
                sha.input(&revocation_base_point.serialize());

                Sha256::from_engine(sha).into_inner()
        };

        let mut part_a = revocation_base_secret.clone();
        part_a.mul_assign(&rev_append_commit_hash_key)?;
        let mut part_b = per_commitment_secret.clone();
        part_b.mul_assign(&commit_append_rev_hash_key)?;
        part_a.add_assign(&part_b[..])?;
        Ok(part_a)
}

/// Derives a per-commitment-transaction revocation public key from its constituent parts. This is
/// the public equivalend of derive_private_revocation_key - using only public keys to derive a
/// public key instead of private keys.
///
/// Note that this is infallible iff we trust that at least one of the two input keys are randomly
/// generated (ie our own).
pub fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, revocation_base_point: &PublicKey) -> Result<PublicKey, secp256k1::Error> {
        let rev_append_commit_hash_key = {
                let mut sha = Sha256::engine();
                sha.input(&revocation_base_point.serialize());
                sha.input(&per_commitment_point.serialize());

                Sha256::from_engine(sha).into_inner()
        };
        let commit_append_rev_hash_key = {
                let mut sha = Sha256::engine();
                sha.input(&per_commitment_point.serialize());
                sha.input(&revocation_base_point.serialize());

                Sha256::from_engine(sha).into_inner()
        };

        let mut part_a = revocation_base_point.clone();
        part_a.mul_assign(&secp_ctx, &rev_append_commit_hash_key)?;
        let mut part_b = per_commitment_point.clone();
        part_b.mul_assign(&secp_ctx, &commit_append_rev_hash_key)?;
        part_a.combine(&part_b)
}

/// 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.
///
/// These keys are assumed to be good, either because the code derived them from
/// channel basepoints via the new function, or they were obtained via
/// PreCalculatedTxCreationKeys.trust_key_derivation because we trusted the source of the
/// pre-calculated keys.
#[derive(PartialEq, Clone)]
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,
        /// A's HTLC Key
        pub a_htlc_key: PublicKey,
        /// B's HTLC Key
        pub 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,
}
impl_writeable!(TxCreationKeys, 33*6,
        { per_commitment_point, revocation_key, a_htlc_key, b_htlc_key, a_delayed_payment_key });

/// The per-commitment point and a set of pre-calculated public keys used for transaction creation
/// in the signer.
/// The pre-calculated keys are an optimization, because ChannelKeys has enough
/// information to re-derive them.
pub struct PreCalculatedTxCreationKeys(TxCreationKeys);

impl PreCalculatedTxCreationKeys {
        /// Create a new PreCalculatedTxCreationKeys from TxCreationKeys
        pub fn new(keys: TxCreationKeys) -> Self {
                PreCalculatedTxCreationKeys(keys)
        }

        /// The pre-calculated transaction creation public keys.
        /// An external validating signer should not trust these keys.
        pub fn trust_key_derivation(&self) -> &TxCreationKeys {
                &self.0
        }

        /// The transaction per-commitment point
        pub fn per_comitment_point(&self) -> &PublicKey {
                &self.0.per_commitment_point
        }
}

/// 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. This is combined with the per-commitment-secret generated by the
        /// counterparty to create a secret which the counterparty can reveal to revoke previous
        /// states.
        pub revocation_basepoint: PublicKey,
        /// The public key which receives our immediately spendable primary channel balance in
        /// remote-broadcasted commitment transactions. This key is static across every commitment
        /// transaction.
        pub payment_point: 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_point,
        delayed_payment_basepoint,
        htlc_basepoint
});


impl TxCreationKeys {
        /// Create a new TxCreationKeys from channel base points and the per-commitment point
        pub 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_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)?,
                        a_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &a_htlc_base)?,
                        b_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &b_htlc_base)?,
                        a_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &a_delayed_payment_base)?,
                })
        }
}

/// A script either spendable by the revocation
/// key or the delayed_payment_key and satisfying the relative-locktime OP_CSV constrain.
/// Encumbering a `to_local` output on a commitment transaction or 2nd-stage HTLC transactions.
pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, to_self_delay: u16, delayed_payment_key: &PublicKey) -> Script {
        Builder::new().push_opcode(opcodes::all::OP_IF)
                      .push_slice(&revocation_key.serialize())
                      .push_opcode(opcodes::all::OP_ELSE)
                      .push_int(to_self_delay as i64)
                      .push_opcode(opcodes::all::OP_CSV)
                      .push_opcode(opcodes::all::OP_DROP)
                      .push_slice(&delayed_payment_key.serialize())
                      .push_opcode(opcodes::all::OP_ENDIF)
                      .push_opcode(opcodes::all::OP_CHECKSIG)
                      .into_script()
}

#[derive(Clone, PartialEq)]
/// Information about an HTLC as it appears in a commitment transaction
pub struct HTLCOutputInCommitment {
        /// Whether the HTLC was "offered" (ie outbound in relation to this commitment transaction).
        /// Note that this is not the same as whether it is ountbound *from us*. To determine that you
        /// need to compare this value to whether the commitment transaction in question is that of
        /// the remote party or our own.
        pub offered: bool,
        /// The value, in msat, of the HTLC. The value as it appears in the commitment transaction is
        /// this divided by 1000.
        pub amount_msat: u64,
        /// The CLTV lock-time at which this HTLC expires.
        pub cltv_expiry: u32,
        /// The hash of the preimage which unlocks this HTLC.
        pub payment_hash: PaymentHash,
        /// The position within the commitment transactions' outputs. This may be None if the value is
        /// below the dust limit (in which case no output appears in the commitment transaction and the
        /// value is spent to additional transaction fees).
        pub transaction_output_index: Option<u32>,
}

impl_writeable!(HTLCOutputInCommitment, 1 + 8 + 4 + 32 + 5, {
        offered,
        amount_msat,
        cltv_expiry,
        payment_hash,
        transaction_output_index
});

#[inline]
pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, a_htlc_key: &PublicKey, b_htlc_key: &PublicKey, revocation_key: &PublicKey) -> Script {
        let payment_hash160 = Ripemd160::hash(&htlc.payment_hash.0[..]).into_inner();
        if htlc.offered {
                Builder::new().push_opcode(opcodes::all::OP_DUP)
                              .push_opcode(opcodes::all::OP_HASH160)
                              .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..])
                              .push_opcode(opcodes::all::OP_EQUAL)
                              .push_opcode(opcodes::all::OP_IF)
                              .push_opcode(opcodes::all::OP_CHECKSIG)
                              .push_opcode(opcodes::all::OP_ELSE)
                              .push_slice(&b_htlc_key.serialize()[..])
                              .push_opcode(opcodes::all::OP_SWAP)
                              .push_opcode(opcodes::all::OP_SIZE)
                              .push_int(32)
                              .push_opcode(opcodes::all::OP_EQUAL)
                              .push_opcode(opcodes::all::OP_NOTIF)
                              .push_opcode(opcodes::all::OP_DROP)
                              .push_int(2)
                              .push_opcode(opcodes::all::OP_SWAP)
                              .push_slice(&a_htlc_key.serialize()[..])
                              .push_int(2)
                              .push_opcode(opcodes::all::OP_CHECKMULTISIG)
                              .push_opcode(opcodes::all::OP_ELSE)
                              .push_opcode(opcodes::all::OP_HASH160)
                              .push_slice(&payment_hash160)
                              .push_opcode(opcodes::all::OP_EQUALVERIFY)
                              .push_opcode(opcodes::all::OP_CHECKSIG)
                              .push_opcode(opcodes::all::OP_ENDIF)
                              .push_opcode(opcodes::all::OP_ENDIF)
                              .into_script()
        } else {
                Builder::new().push_opcode(opcodes::all::OP_DUP)
                              .push_opcode(opcodes::all::OP_HASH160)
                              .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..])
                              .push_opcode(opcodes::all::OP_EQUAL)
                              .push_opcode(opcodes::all::OP_IF)
                              .push_opcode(opcodes::all::OP_CHECKSIG)
                              .push_opcode(opcodes::all::OP_ELSE)
                              .push_slice(&b_htlc_key.serialize()[..])
                              .push_opcode(opcodes::all::OP_SWAP)
                              .push_opcode(opcodes::all::OP_SIZE)
                              .push_int(32)
                              .push_opcode(opcodes::all::OP_EQUAL)
                              .push_opcode(opcodes::all::OP_IF)
                              .push_opcode(opcodes::all::OP_HASH160)
                              .push_slice(&payment_hash160)
                              .push_opcode(opcodes::all::OP_EQUALVERIFY)
                              .push_int(2)
                              .push_opcode(opcodes::all::OP_SWAP)
                              .push_slice(&a_htlc_key.serialize()[..])
                              .push_int(2)
                              .push_opcode(opcodes::all::OP_CHECKMULTISIG)
                              .push_opcode(opcodes::all::OP_ELSE)
                              .push_opcode(opcodes::all::OP_DROP)
                              .push_int(htlc.cltv_expiry as i64)
                              .push_opcode(opcodes::all::OP_CLTV)
                              .push_opcode(opcodes::all::OP_DROP)
                              .push_opcode(opcodes::all::OP_CHECKSIG)
                              .push_opcode(opcodes::all::OP_ENDIF)
                              .push_opcode(opcodes::all::OP_ENDIF)
                              .into_script()
        }
}

/// note here that 'a_revocation_key' is generated using b_revocation_basepoint and a's
/// commitment secret. 'htlc' does *not* need to have its previous_output_index filled.
#[inline]
pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys) -> Script {
        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: &Txid, feerate_per_kw: u32, to_self_delay: u16, htlc: &HTLCOutputInCommitment, a_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
        let mut txins: Vec<TxIn> = Vec::new();
        txins.push(TxIn {
                previous_output: OutPoint {
                        txid: prev_hash.clone(),
                        vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"),
                },
                script_sig: Script::new(),
                sequence: 0,
                witness: Vec::new(),
        });

        let total_fee = if htlc.offered {
                        feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000
                } else {
                        feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000
                };

        let mut txouts: Vec<TxOut> = Vec::new();
        txouts.push(TxOut {
                script_pubkey: get_revokeable_redeemscript(revocation_key, to_self_delay, a_delayed_payment_key).to_v0_p2wsh(),
                value: htlc.amount_msat / 1000 - total_fee //TODO: BOLT 3 does not specify if we should add amount_msat before dividing or if we should divide by 1000 before subtracting (as we do here)
        });

        Transaction {
                version: 2,
                lock_time: if htlc.offered { htlc.cltv_expiry } else { 0 },
                input: txins,
                output: txouts,
        }
}

#[derive(Clone)]
/// We use this to track local commitment transactions and put off signing them until we are ready
/// to broadcast. This class can be used inside a signer implementation to generate a signature
/// given the relevant secret key.
pub struct LocalCommitmentTransaction {
        // TODO: We should migrate away from providing the transaction, instead providing enough to
        // allow the ChannelKeys to construct it from scratch. Luckily we already have HTLC data here,
        // so we're probably most of the way there.
        /// The commitment transaction itself, in unsigned form.
        pub unsigned_tx: Transaction,
        /// Our counterparty's signature for the transaction, above.
        pub their_sig: Signature,
        // Which order the signatures should go in when constructing the final commitment tx witness.
        // The user should be able to reconstruc this themselves, so we don't bother to expose it.
        our_sig_first: bool,
        pub(crate) local_keys: TxCreationKeys,
        /// The feerate paid per 1000-weight-unit in this commitment transaction. This value is
        /// controlled by the channel initiator.
        pub feerate_per_kw: u32,
        /// The HTLCs and remote htlc signatures which were included in this commitment transaction.
        ///
        /// Note that this includes all HTLCs, including ones which were considered dust and not
        /// actually included in the transaction as it appears on-chain, but who's value is burned as
        /// fees and not included in the to_local or to_remote outputs.
        ///
        /// The remote HTLC signatures in the second element will always be set for non-dust HTLCs, ie
        /// those for which transaction_output_index.is_some().
        pub per_htlc: Vec<(HTLCOutputInCommitment, Option<Signature>)>,
}
impl LocalCommitmentTransaction {
        #[cfg(test)]
        pub fn dummy() -> Self {
                let dummy_input = TxIn {
                        previous_output: OutPoint {
                                txid: Default::default(),
                                vout: 0,
                        },
                        script_sig: Default::default(),
                        sequence: 0,
                        witness: vec![]
                };
                let dummy_key = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&[42; 32]).unwrap());
                let dummy_sig = Secp256k1::new().sign(&secp256k1::Message::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap());
                Self {
                        unsigned_tx: Transaction {
                                version: 2,
                                input: vec![dummy_input],
                                output: Vec::new(),
                                lock_time: 0,
                        },
                        their_sig: dummy_sig,
                        our_sig_first: false,
                        local_keys: TxCreationKeys {
                                        per_commitment_point: dummy_key.clone(),
                                        revocation_key: dummy_key.clone(),
                                        a_htlc_key: dummy_key.clone(),
                                        b_htlc_key: dummy_key.clone(),
                                        a_delayed_payment_key: dummy_key.clone(),
                                },
                        feerate_per_kw: 0,
                        per_htlc: Vec::new()
                }
        }

        /// Generate a new LocalCommitmentTransaction based on a raw commitment transaction,
        /// remote signature and both parties keys
        pub fn new_missing_local_sig(unsigned_tx: Transaction, their_sig: Signature, our_funding_key: &PublicKey, their_funding_key: &PublicKey, local_keys: TxCreationKeys, feerate_per_kw: u32, htlc_data: Vec<(HTLCOutputInCommitment, Option<Signature>)>) -> LocalCommitmentTransaction {
                if unsigned_tx.input.len() != 1 { panic!("Tried to store a commitment transaction that had input count != 1!"); }
                if unsigned_tx.input[0].witness.len() != 0 { panic!("Tried to store a signed commitment transaction?"); }

                Self {
                        unsigned_tx,
                        their_sig,
                        our_sig_first: our_funding_key.serialize()[..] < their_funding_key.serialize()[..],
                        local_keys,
                        feerate_per_kw,
                        per_htlc: htlc_data,
                }
        }

        /// The pre-calculated transaction creation public keys.
        /// An external validating signer should not trust these keys.
        pub fn trust_key_derivation(&self) -> &TxCreationKeys {
                &self.local_keys
        }

        /// Get the txid of the local commitment transaction contained in this
        /// LocalCommitmentTransaction
        pub fn txid(&self) -> Txid {
                self.unsigned_tx.txid()
        }

        /// Gets our signature for the contained commitment transaction given our funding private key.
        ///
        /// Funding key is your key included in the 2-2 funding_outpoint lock. Should be provided
        /// by your ChannelKeys.
        /// Funding redeemscript is script locking funding_outpoint. This is the mutlsig script
        /// between your own funding key and your counterparty's. Currently, this is provided in
        /// ChannelKeys::sign_local_commitment() calls directly.
        /// Channel value is amount locked in funding_outpoint.
        pub fn get_local_sig<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
                let sighash = hash_to_message!(&bip143::SighashComponents::new(&self.unsigned_tx)
                        .sighash_all(&self.unsigned_tx.input[0], funding_redeemscript, channel_value_satoshis)[..]);
                secp_ctx.sign(&sighash, funding_key)
        }

        pub(crate) fn add_local_sig(&self, funding_redeemscript: &Script, our_sig: Signature) -> Transaction {
                let mut tx = self.unsigned_tx.clone();
                // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
                tx.input[0].witness.push(Vec::new());

                if self.our_sig_first {
                        tx.input[0].witness.push(our_sig.serialize_der().to_vec());
                        tx.input[0].witness.push(self.their_sig.serialize_der().to_vec());
                } else {
                        tx.input[0].witness.push(self.their_sig.serialize_der().to_vec());
                        tx.input[0].witness.push(our_sig.serialize_der().to_vec());
                }
                tx.input[0].witness[1].push(SigHashType::All as u8);
                tx.input[0].witness[2].push(SigHashType::All as u8);

                tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec());
                tx
        }

        /// Get a signature for each HTLC which was included in the commitment transaction (ie for
        /// which HTLCOutputInCommitment::transaction_output_index.is_some()).
        ///
        /// The returned Vec has one entry for each HTLC, and in the same order. For HTLCs which were
        /// considered dust and not included, a None entry exists, for all others a signature is
        /// included.
        pub fn get_htlc_sigs<T: secp256k1::Signing + secp256k1::Verification>(&self, htlc_base_key: &SecretKey, local_csv: u16, secp_ctx: &Secp256k1<T>) -> Result<Vec<Option<Signature>>, ()> {
                let txid = self.txid();
                let mut ret = Vec::with_capacity(self.per_htlc.len());
                let our_htlc_key = derive_private_key(secp_ctx, &self.local_keys.per_commitment_point, htlc_base_key).map_err(|_| ())?;

                for this_htlc in self.per_htlc.iter() {
                        if this_htlc.0.transaction_output_index.is_some() {
                                let htlc_tx = build_htlc_transaction(&txid, self.feerate_per_kw, local_csv, &this_htlc.0, &self.local_keys.a_delayed_payment_key, &self.local_keys.revocation_key);

                                let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc.0, &self.local_keys.a_htlc_key, &self.local_keys.b_htlc_key, &self.local_keys.revocation_key);

                                let sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, this_htlc.0.amount_msat / 1000)[..]);
                                ret.push(Some(secp_ctx.sign(&sighash, &our_htlc_key)));
                        } else {
                                ret.push(None);
                        }
                }
                Ok(ret)
        }

        /// Gets a signed HTLC transaction given a preimage (for !htlc.offered) and the local HTLC transaction signature.
        pub(crate) fn get_signed_htlc_tx(&self, htlc_index: usize, signature: &Signature, preimage: &Option<PaymentPreimage>, local_csv: u16) -> Transaction {
                let txid = self.txid();
                let this_htlc = &self.per_htlc[htlc_index];
                assert!(this_htlc.0.transaction_output_index.is_some());
                // if we don't have preimage for an HTLC-Success, we can't generate an HTLC transaction.
                if !this_htlc.0.offered && preimage.is_none() { unreachable!(); }
                // Further, we should never be provided the preimage for an HTLC-Timeout transaction.
                if  this_htlc.0.offered && preimage.is_some() { unreachable!(); }

                let mut htlc_tx = build_htlc_transaction(&txid, self.feerate_per_kw, local_csv, &this_htlc.0, &self.local_keys.a_delayed_payment_key, &self.local_keys.revocation_key);
                // Channel should have checked that we have a remote signature for this HTLC at
                // creation, and we should have a sensible htlc transaction:
                assert!(this_htlc.1.is_some());

                let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc.0, &self.local_keys.a_htlc_key, &self.local_keys.b_htlc_key, &self.local_keys.revocation_key);

                // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
                htlc_tx.input[0].witness.push(Vec::new());

                htlc_tx.input[0].witness.push(this_htlc.1.unwrap().serialize_der().to_vec());
                htlc_tx.input[0].witness.push(signature.serialize_der().to_vec());
                htlc_tx.input[0].witness[1].push(SigHashType::All as u8);
                htlc_tx.input[0].witness[2].push(SigHashType::All as u8);

                if this_htlc.0.offered {
                        // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
                        htlc_tx.input[0].witness.push(Vec::new());
                } else {
                        htlc_tx.input[0].witness.push(preimage.unwrap().0.to_vec());
                }

                htlc_tx.input[0].witness.push(htlc_redeemscript.as_bytes().to_vec());
                htlc_tx
        }
}
impl PartialEq for LocalCommitmentTransaction {
        // We dont care whether we are signed in equality comparison
        fn eq(&self, o: &Self) -> bool {
                self.txid() == o.txid()
        }
}
impl Writeable for LocalCommitmentTransaction {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
                if let Err(e) = self.unsigned_tx.consensus_encode(&mut WriterWriteAdaptor(writer)) {
                        match e {
                                encode::Error::Io(e) => return Err(e),
                                _ => panic!("local tx must have been well-formed!"),
                        }
                }
                self.their_sig.write(writer)?;
                self.our_sig_first.write(writer)?;
                self.local_keys.write(writer)?;
                self.feerate_per_kw.write(writer)?;
                writer.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
                for &(ref htlc, ref sig) in self.per_htlc.iter() {
                        htlc.write(writer)?;
                        sig.write(writer)?;
                }
                Ok(())
        }
}
impl Readable for LocalCommitmentTransaction {
        fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
                let unsigned_tx = match Transaction::consensus_decode(reader.by_ref()) {
                        Ok(tx) => tx,
                        Err(e) => match e {
                                encode::Error::Io(ioe) => return Err(DecodeError::Io(ioe)),
                                _ => return Err(DecodeError::InvalidValue),
                        },
                };
                let their_sig = Readable::read(reader)?;
                let our_sig_first = Readable::read(reader)?;
                let local_keys = Readable::read(reader)?;
                let feerate_per_kw = Readable::read(reader)?;
                let htlcs_count: u64 = Readable::read(reader)?;
                let mut per_htlc = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / mem::size_of::<(HTLCOutputInCommitment, Option<Signature>)>()));
                for _ in 0..htlcs_count {
                        let htlc: HTLCOutputInCommitment = Readable::read(reader)?;
                        let sigs = Readable::read(reader)?;
                        per_htlc.push((htlc, sigs));
                }

                if unsigned_tx.input.len() != 1 {
                        // Ensure tx didn't hit the 0-input ambiguity case.
                        return Err(DecodeError::InvalidValue);
                }
                Ok(Self {
                        unsigned_tx,
                        their_sig,
                        our_sig_first,
                        local_keys,
                        feerate_per_kw,
                        per_htlc,
                })
        }
}

#[cfg(test)]
mod tests {
        use super::CounterpartyCommitmentSecrets;
        use hex;

        #[test]
        fn test_per_commitment_storage() {
                // Test vectors from BOLT 3:
                let mut secrets: Vec<[u8; 32]> = Vec::new();
                let mut monitor;

                macro_rules! test_secrets {
                        () => {
                                let mut idx = 281474976710655;
                                for secret in secrets.iter() {
                                        assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
                                        idx -= 1;
                                }
                                assert_eq!(monitor.get_min_seen_secret(), idx + 1);
                                assert!(monitor.get_secret(idx).is_none());
                        };
                }

                {
                        // insert_secret correct sequence
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                        monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                        monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                        monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
                        monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
                        monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
                        monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
                        monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();
                }

                {
                        // insert_secret #1 incorrect
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                        assert!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).is_err());
                }

                {
                        // insert_secret #2 incorrect (#1 derived from incorrect)
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
                        monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                        monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                        assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
                }

                {
                        // insert_secret #3 incorrect
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                        monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
                        monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                        assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
                }

                {
                        // insert_secret #4 incorrect (1,2,3 derived from incorrect)
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
                        monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
                        monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
                        monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
                        monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
                        monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
                        monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
                        assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
                }

                {
                        // insert_secret #5 incorrect
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                        monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                        monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                        monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
                        monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
                        assert!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).is_err());
                }

                {
                        // insert_secret #6 incorrect (5 derived from incorrect)
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                        monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                        monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                        monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
                        monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
                        monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
                        monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
                        assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
                }

                {
                        // insert_secret #7 incorrect
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                        monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                        monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                        monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
                        monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
                        monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
                        monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
                        assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
                }

                {
                        // insert_secret #8 incorrect
                        monitor = CounterpartyCommitmentSecrets::new();
                        secrets.clear();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
                        monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                        monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                        monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                        monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
                        monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
                        monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
                        monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
                        test_secrets!();

                        secrets.push([0; 32]);
                        secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
                        assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
                }
        }
}