Merge pull request #1349 from TheBlueMatt/2022-03-listen-send-sync

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

diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs
index 8f66de53555657f9419c4d0c66f7382422369083..6dc05c2ef3c09e2fcd5fc16ad8a2ebe2427343d3 100644 (file)
--- a/lightning/src/ln/chan_utils.rs
+++ b/lightning/src/ln/chan_utils.rs
@@ -140,10 +140,10 @@ pub fn build_closing_transaction(to_holder_value_sat: u64, to_counterparty_value
 /// 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
+/// Allows us to keep track of all of the revocation secrets of our counterparty in just 50*32 bytes
 /// or so.
 #[derive(Clone)]
-pub(crate) struct CounterpartyCommitmentSecrets {
+pub struct CounterpartyCommitmentSecrets {
        old_secrets: [([u8; 32], u64); 49],
 }
 
@@ -159,7 +159,8 @@ impl PartialEq for CounterpartyCommitmentSecrets {
 }
 
 impl CounterpartyCommitmentSecrets {
-       pub(crate) fn new() -> Self {
+       /// Creates a new empty `CounterpartyCommitmentSecrets` structure.
+       pub fn new() -> Self {
                Self { old_secrets: [([0; 32], 1 << 48); 49], }
        }
 
@@ -173,7 +174,9 @@ impl CounterpartyCommitmentSecrets {
                48
        }
 
-       pub(crate) fn get_min_seen_secret(&self) -> u64 {
+       /// Returns the minimum index of all stored secrets. Note that indexes start
+       /// at 1 << 48 and get decremented by one for each new secret.
+       pub fn get_min_seen_secret(&self) -> u64 {
                //TODO This can be optimized?
                let mut min = 1 << 48;
                for &(_, idx) in self.old_secrets.iter() {
@@ -197,7 +200,9 @@ impl CounterpartyCommitmentSecrets {
                res
        }
 
-       pub(crate) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> {
+       /// Inserts the `secret` at `idx`. Returns `Ok(())` if the secret
+       /// was generated in accordance with BOLT 3 and is consistent with previous secrets.
+       pub 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];
@@ -212,8 +217,9 @@ impl CounterpartyCommitmentSecrets {
                Ok(())
        }
 
-       /// Can only fail if idx is < get_min_seen_secret
-       pub(crate) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
+       /// Returns the secret at `idx`.
+       /// Returns `None` if `idx` is < [`CounterpartyCommitmentSecrets::get_min_seen_secret`].
+       pub 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))
@@ -1245,7 +1251,7 @@ impl CommitmentTransaction {
                                if let &Some(ref b_htlcout) = b {
                                        a_htlcout.cltv_expiry.cmp(&b_htlcout.cltv_expiry)
                                                // Note that due to hash collisions, we have to have a fallback comparison
-                                               // here for fuzztarget mode (otherwise at least chanmon_fail_consistency
+                                               // here for fuzzing mode (otherwise at least chanmon_fail_consistency
                                                // may fail)!
                                                .then(a_htlcout.payment_hash.0.cmp(&b_htlcout.payment_hash.0))
                                // For non-HTLC outputs, if they're copying our SPK we don't really care if we