Update API for writeable async offer cache to be bytes
What the developer wrote
Authored by Valentine Wallace
Update API for writeable async offer cache to be bytes
The previous API wouldn't work for language bindings.
What changed, and why it matters
This is a small API refactor in a Lightning network library. It changes one internal persistence helper from returning a generic 'writeable' object to returning raw bytes, so it can be more easily used across language bindings. There is no direct evidence this fixes a security vulnerability.
No immediate security action required. Treat as a normal API/serialization refactor. If auditing, verify that the new `WithoutLength` serialization remains backward-compatible or properly version-gated during persistence deserialization.
Security signals we found
Serialization format change for persisted state
API signature change from `impl Writeable` to `Vec<u8>`
Use of `WithoutLength` wrapper in TLV serialization
Evidence from the diff
The commit modifies ChannelManager::write to persist self.flow.writeable_async_receive_offer_cache() wrapped in WithoutLength(...), and changes Flow::writeable_async_receive_offer_cache to return Vec<u8> instead of impl Writeable + '_. The stated reason is compatibility with language bindings. The change removes a length prefix from the serialized field in ChannelManager’s TLV stream by using WithoutLength, because the underlying value is now already encoded as bytes. This is a serialization/API adjustment, not a patch for a disclosed vulnerability.
Changed components
lightning/src/ln/channelmanager.rslightning/src/offers/flow.rsInspect captured patch +4 / −4
diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index fa584dd..923632a 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -130,7 +130,7 @@ use crate::util::logger::{Level, Logger, WithContext};
use crate::util::scid_utils::fake_scid;
use crate::util::ser::{
BigSize, FixedLengthReader, LengthReadable, MaybeReadable, Readable, ReadableArgs, VecWriter,
- Writeable, Writer,
+ WithoutLength, Writeable, Writer,
};
use crate::util::wakers::{Future, Notifier};
@@ -15248,7 +15248,7 @@ where
(15, self.inbound_payment_id_secret, required),
(17, in_flight_monitor_updates, option),
(19, peer_storage_dir, optional_vec),
- (21, self.flow.writeable_async_receive_offer_cache(), required),
+ (21, WithoutLength(&self.flow.writeable_async_receive_offer_cache()), required),
});
Ok(())
diff --git a/lightning/src/offers/flow.rs b/lightning/src/offers/flow.rs
index dde7d58..6bc9f3c 100644
--- a/lightning/src/offers/flow.rs
+++ b/lightning/src/offers/flow.rs
@@ -1657,8 +1657,8 @@ where
cache.static_invoice_persisted(context, self.duration_since_epoch())
}
- /// Get the [`AsyncReceiveOfferCache`] for persistence.
- pub fn writeable_async_receive_offer_cache(&self) -> impl Writeable + '_ {
+ /// Get the encoded [`AsyncReceiveOfferCache`] for persistence.
+ pub fn writeable_async_receive_offer_cache(&self) -> Vec<u8> {
self.async_receive_offer_cache.encode()
}
}
Why this scored 17/100
Community notes
Notes can correct, qualify, or add evidence to the AI analysis. Every note shown here has been validated by a human moderator.
The AI analysis stands alone for now. Submit a note if you can add evidence or important context.