Bound incoming HTLC witnessScript to min/max limits

[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 747e622f075f0bc86c9072d7e86b4df3e0c55101..a0cd3048f7e2dff07d8ba85fbfae20bd32782df5 100644 (file)
--- a/lightning/src/ln/chan_utils.rs
+++ b/lightning/src/ln/chan_utils.rs
@@ -25,6 +25,25 @@ use secp256k1;
 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.