This commit improves TLV decoding safety and consistency across multiple
packages by enforcing fixed-length requirements and adding unit tests to
prevent malformed TLV records from being accepted.
Changes include:
- lnwire:
* Enforce 8-byte length in Fee TLV decoder.
* Enforce PubNonceSize in Musig2Nonce TLV decoder.
* Enforce 8-byte length in ShortChannelID TLV decoder.
* Added roundtrip and invalid length tests for Fee, Musig2Nonce,
and ShortChannelID records.
- routing/route:
* Enforce Vertex TLV length (33 bytes).
* Added encode/decode and invalid length tests for Vertex.
- tlv:
* Enforce correct length in DBytes33 decoder (33 bytes).
* Added tests ensuring all fixed-size primitive decoders reject
incorrect TLV lengths.
By strictly validating TLV lengths, we prevent malformed or corrupted
TLV records from being silently accepted, improving protocol safety.
Erick Cestari
5a7925008e