quick urkel tree test

attack.js

const bcrypto = require('bcrypto');
const random = require('bcrypto/lib/random');
const BN = require('bcrypto/lib/bn.js');
const urkel = require('urkel/radix');
//const urkel = require('urkel/trie');
const {BLAKE2b} = bcrypto;
const {randomBytes} = random;
const {Tree, Proof} = urkel;

const dir = process.cwd();

(async () => {
  const tree = new Tree(BLAKE2b, 256, dir);

  await tree.open();
  const txn = tree.transaction();

  const key = Buffer.alloc(32);
  const value = randomBytes(300);

  let k = new BN(1);
  for (let i = 0; i < 256; i++) {
     const v = randomBytes(300);
     const buf = k.toBuffer('be', 32);
     await txn.insert(buf, v);
     k.ishl(new BN(1))
   }
  
  const root = await txn.commit();                                                              
  const snapshot = tree.snapshot(root);                                                         

  const proof = await snapshot.prove(key)                                                       
  console.log(proof.nodes.length)                                                               
})().catch(err => {                    
  console.log(err
});

urkel-test.js

// npm install urkel bcrypto

const bcrypto = require('bcrypto');
const random = require('bcrypto/lib/random');
const urkel = require('urkel');
const {BLAKE2b} = bcrypto;
const {randomBytes} = random;
const {Tree, Proof} = urkel;

const dir = process.cwd();

(async () => {
  const tree = new Tree(BLAKE2b, 256, dir);

  await tree.open();
  const txn = tree.transaction();

  const k1 = Buffer.alloc(32);
  const v1 = randomBytes(300);

  const k2 = Buffer.alloc(32);
  k2[31] = 1;
  const v2 = randomBytes(300);

  await txn.insert(k1, v1);
  await txn.insert(k2, v2);

  const root = await txn.commit();
  const snapshot = tree.snapshot(root);

  const proof = await snapshot.prove(k1);
  console.log(proof.nodes.length)
})().catch(err => {
  console.log(err)
});