exonum-client-cis/lib/blockchain/block.js

Light Client for Exonum CIS Blockchain

"use strict";

var _interopRequireWildcard = require("@babel/runtime/helpers/interopRequireWildcard");

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.verifyBlock = verifyBlock;
exports.protocol = void 0;

var Long = _interopRequireWildcard(require("long"));

var protocol = _interopRequireWildcard(require("../../proto/protocol.js"));

exports.protocol = protocol;

var _convert = require("../types/convert");

var _crypto = require("../crypto");

/**
 * Validate block and each precommit in block
 * @param {Object} data
 * @param {Array} validators
 * @return {Promise}
 */
function verifyBlock(data, validators) {
  return new Promise(function (resolve) {
    var block = {
      prev_hash: {
        data: (0, _convert.hexadecimalToUint8Array)(data.block.prev_hash)
      },
      tx_hash: {
        data: (0, _convert.hexadecimalToUint8Array)(data.block.tx_hash)
      },
      state_hash: {
        data: (0, _convert.hexadecimalToUint8Array)(data.block.state_hash)
      }
    };
    var blockHash;

    if (data.block.proposer_id !== 0) {
      block.proposer_id = data.block.proposer_id;
    }

    if (data.block.height !== 0) {
      block.height = data.block.height;
    }

    if (data.block.tx_count !== 0) {
      block.tx_count = data.block.tx_count;
    }

    var message = protocol.exonum.Block.create(block);
    var buffer = new Uint8Array(protocol.exonum.Block.encode(message).finish());
    blockHash = (0, _crypto.hash)(buffer);

    for (var i = 0; i < data.precommits.length; i++) {
      var precommit = data.precommits[i];

      var _buffer = (0, _convert.hexadecimalToUint8Array)(precommit);

      var singedMsg = protocol.exonum.consensus.SignedMessage.decode(new Uint8Array(_buffer));

      var _message = protocol.exonum.consensus.ExonumMessage.decode(singedMsg.payload);

      _message = _message.precommit;
      var plain = protocol.exonum.consensus.Precommit.toObject(_message);

      if (Long.fromValue(plain.height).compare(Long.fromValue(data.block.height)) !== 0) {
        throw new Error('Precommit height is not match with block height');
      }

      if ((0, _convert.uint8ArrayToHexadecimal)(plain.block_hash.data) !== blockHash) {
        throw new Error('Precommit block hash is not match with calculated block hash');
      }

      var publicKey = validators[plain.validator || 0];

      if ((0, _convert.uint8ArrayToHexadecimal)(singedMsg.author.data) !== publicKey) {
        throw new Error('Precommit public key is not match with buffer');
      }

      var signature = (0, _convert.uint8ArrayToHexadecimal)(singedMsg.signature.data);

      if (!(0, _crypto.verifySignature)(signature, publicKey, singedMsg.payload)) {
        throw new Error('Precommit signature is wrong');
      }
    }

    resolve();
  });
}