Component: CrossChainRelayUpgradeable

Description

The CrossChainRelayUpgradeable contract is responsible for sending and receiving cross-chain messages between the chain with the ledger and the chain with the vault. It inherits from the LayerZero V1 LzApp. It does not handle any business logic; it only calls receiveMessage in VaultCrossChainManager or LedgerCrossChainManager.

Invariants

1. Authorization

   • Only approved callers can send cross-chain messages.

   • Only approved source chains can send messages to this contract.

2. Message processing

   • When receiving a message, it calls receiveMessage in the _managerAddress. Each CrossChainRelay contract has either VaultCrossChainManager or LedgerCrossChainManager as its _managerAddress.

Attack surface

• Cross-chain--message integrity

  • This contract inherits from LayerZero V1 LzApp, so it only accepts messages from the LayerZero Endpoint.

  • The attacker cannot manipulate messages from either the Protocol Vault Ledger or the Protocol Vault contract.