o2-client/lib/blockchain/block.js

Light Client for O2 Blockchain

'use strict';

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

var _primitive = require('../types/primitive');

var primitive = _interopRequireWildcard(_primitive);

var _message = require('../types/message');

var _hexadecimal = require('../types/hexadecimal');

var _generic = require('../types/generic');

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

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

var _helpers = require('../helpers');

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

var Block = (0, _generic.newType)({
  fields: [{ name: 'proposer_id', type: primitive.Uint16 }, { name: 'height', type: primitive.Uint64 }, { name: 'tx_count', type: primitive.Uint32 }, { name: 'prev_hash', type: _hexadecimal.Hash }, { name: 'tx_hash', type: _hexadecimal.Hash }, { name: 'state_hash', type: _hexadecimal.Hash }]
});
var SystemTime = (0, _generic.newType)({
  fields: [{ name: 'secs', type: primitive.Uint64 }, { name: 'nanos', type: primitive.Uint32 }]
});

/**
 * Validate block and each precommit in block
 * @param {Object} data
 * @param {Array} validators
 * @return {boolean}
 */
function verifyBlock(data, validators) {
  var blockHash = void 0;
  try {
    blockHash = (0, _crypto.hash)(data.block, Block);
  } catch (error) {
    return false;
  }

  for (var i = 0; i < data.precommits.length; i++) {
    var precommit = data.precommits[i];
    var buffer = (0, _convert.hexadecimalToUint8Array)(precommit.message);

    if (precommit.payload.height !== data.block.height) {
      // height of block is not match
      return false;
    }

    if (precommit.payload.block_hash !== blockHash) {
      // hash of block is not match
      return false;
    }

    var publicKey = validators[precommit.payload.validator];
    if ((0, _convert.uint8ArrayToHexadecimal)(buffer.slice(0, _hexadecimal.PUBLIC_KEY_LENGTH)) !== publicKey) {
      // public key is not match
      return false;
    }

    var Precommit = (0, _message.newPrecommit)({
      author: publicKey,
      fields: [{ name: 'validator', type: primitive.Uint16 }, { name: 'height', type: primitive.Uint64 }, { name: 'round', type: primitive.Uint32 }, { name: 'propose_hash', type: _hexadecimal.Hash }, { name: 'block_hash', type: _hexadecimal.Hash }, { name: 'time', type: SystemTime }]
    });

    var precommitBody = buffer.slice(0, buffer.length - _message.SIGNATURE_LENGTH);

    if (!(0, _helpers.compareUint8Arrays)(Precommit.serialize(precommit.payload), precommitBody)) {
      // payload is not match
      return false;
    }

    var signature = (0, _convert.uint8ArrayToHexadecimal)(buffer.slice(buffer.length - _message.SIGNATURE_LENGTH, buffer.length));

    try {
      if (!(0, _crypto.verifySignature)(signature, publicKey, precommitBody)) {
        // signature is not match
        return false;
      }
    } catch (error) {
      return false;
    }
  }

  return true;
}