besu.md

Besu Views

• RFC: 03-005
• Authors: Sandeep Nishad, Dhinakaran Vinayagamurthy, Venkatraman Ramakrishna, Krishnasuri Narayanam
• Status: Draft
• Since: 05-Jan-2023

Summary

This document specifies the design of view address for remote query to Besu networks, and the structure of Besu View which is returned as response of the remote query.

Addressing a Besu View

operator = network-id , ":" , contract-address , ":" , func-name-with-signature , [ ":" , { argument } ] ;

Example:

• Network-id: 123
• contract-address: 0x5FbDB2315678afecb367f032d93F642f64180aa3
• Function Name: get(string)
• Arguments: key

operator = 123:0x5FbDB2315678afecb367f032d93F642f64180aa3:get(string):key

View Data Definition

The view from a Besu network ledger is specified below. It consists of endorsed (i.e., signed) response to state requests made

1. Interop payload in bytes (check if the requestor can directly obtain this from the output merkle-patricia-trie proof verification)
2. Header fields of block object (this also contains receiptsRoot).
3. Merkle-Patricia Proof
4. Index of receipt object of interest -> txRIndex.
5. LogIndex
6. Signatures of validators from extraData (we can obtain a validator's public key from its signature using recover)

Take a view at Besu Block Header Fields

syntax = "proto3";

message BlockHeader {
  // Fields representing the header of a block object
  string parentHash = 1;
  string sha3Uncles = 2;
  string miner = 3;
  string stateRoot = 4;
  string transactionsRoot = 5;
  string receiptsRoot = 6;
  string logsBloom = 7;
  string difficulty = 8;
  string number = 9;
  string gasLimit = 10;
  string gasUsed = 11;
  string timestamp = 12;
  string extraData = 13;
  string mixHash = 14;
  string nonce = 15;
  // ...
}

message BesuView {
  bytes interop_payload = 1;
  BlockHeader block_header = 2;
  bytes merkle_proof = 3;
  uint32 receipt_index = 4;
  uint32 log_index = 5;
  repeated bytes validator_signatures = 6;
}

You can find the besu view_data.proto file here.