SbercoinJS Wallet

This is a client-side wallet library that can generate private keys from a mnemonic, or import private keys from other Sbercoin.com wallets.

It can sign transactions locally, and submit the raw transaction data to a remote Sbercoin.com node. The blockchain data is provided by the Insight API (which powers https://explorer.sbercoin.com/), rather than the raw sbercoind RPC calls.

This library makes it possible to run DApp without the users having to run a full sbercoind node.

This library is extracted from the official Sbercoin.com web wallet.

Install

yarn add sbercoinjs-wallet

Running Tests

The sbercoinjs-wallet depends on a number of external services. To run the unit tests, you'll need to start the services using docker-compose.

npm run start-services

Then run the tests:

npm run test

Or, to rebuild and rerun tests automatically:

npm run test-watch

If you did not terminate the testing docker services properly, run the clean task first before restart:

npm run clean

Implementation Notes

There are some differences from the original web wallet repo.

• Removed VUE specific code.
• Removed reactive data setters that are intended to trigger view updates, to make this a plain-old JavaScript module.
• Each wallet instance is instantiated with a network explicitly. This allows simultaneous use of different networks.
• TypeScript for type hinting.
• Uses greph (1e7) as internal units
  • Can represent up to ~90 million SBER accurately.
• Uses coinselect to select utxos.
  • Taking into account the size of a transaction, and multiplies that by fee rate per byte.
  • Uses blackjack algorithm, and fallbacks to simple accumulative.
• Set tx relay fee automatically from fee rate reported by the network.
• send-to-contract transaction can transfer value to the contract

API

• Networks
  • fromWIF
  • fromMnemonic
  • fromEncryptedPrivateKey
• Wallet
  • async wallet.getInfo
  • async wallet.send
  • async wallet.sendEstimateMaxValue
  • async wallet.generateTx
  • async wallet.contractSend
  • async wallet.contractSendEstimateMaxValue
  • async wallet.generateContractSendTx
  • async wallet.contractCall
  • async getTransactions
  • toEncryptedPrivateKey
  • deriveChildWallet

Examples

Create Mnemonic+Password Wallet

import { networks, generateMnemonic } from "sbercoinjs-wallet";

async function main() {
  const network = networks.testnet;
  const mnemonic = generateMnemonic();
  const password = "covfefe";

  const wallet = network.fromMnemonic(mnemonic, password);

  console.log("mnemonic:", mnemonic);
  console.log("public address:", wallet.address);
  console.log("private key (WIF):", wallet.toWIF());
}

main().catch(err => console.log(err));

Example Output:

mnemonic: hold struggle ready lonely august napkin enforce retire pipe where avoid drip
public address: qLUHmrFGexxpyHwQphLpE1czZNFE5m1xmV
private key (WIF): cNQKccYYQyGX9G9Qxq2DJev9jHygbZpb2UG7EvUapbtDx5XhkhYE

Send Fund

This example restores a wallet from a private key (in WIF format), then sending value to another address.

The transaction is signed locally, and the transaction submitted to a remote API.

The currency unit used is greph. To convert SBER to Greph you should multiply the amount you want with 1e7.

import { networks } from "sbercoinjs-wallet";

async function main() {
  // Use the test network. Or `networks.mainnet`
  const network = networks.testnet;

  const wif = "cU4ficvRNvR7jnbtczCWo5s9rB9Tdg1U4LkArVpGU6cKnDq7LFoP";
  const wallet = network.fromWIF(wif);

  console.log(wallet.address);

  const toAddr = "qS3ThpDn4HRH9we2hZUdF3F3uR7TTvpZ9v";
  // Sending 0.1 SBER
  const sendtx = await wallet.send(toAddr, 0.01 * 1e7, { feeRate: 500 });
  console.log("sendtx", sendtx);
}

main().catch(err => console.log(err));

Send To Contract

Let's burn some money using the Burn contract:

pragma solidity ^0.4.18;

contract Burn {
  uint256 public totalburned;
  event DidBurn(address burnerAddress, uint256 burnedAmount);

  function burnbabyburn() public payable {
    totalburned = msg.value;
    DidBurn(msg.sender, msg.value);
  }
}

The ABI encoding for the burnbabyburn() invokation is e179b912. We'll burn 0.05 SBER, expressed in unit of greph.

import { networks } from "sbercoinjs-wallet";

async function main() {
  const network = networks.testnet;

  const privateKey = "cU4ficvRNvR7jnbtczCWo5s9rB9Tdg1U4LkArVpGU6cKnDq7LFoP";

  const wallet = network.fromWIF(privateKey);

  const contractAddress = "b10071ee33512ce8a0c06ecbc14a5f585a27a3e2";
  const encodedData = "e179b912"; // burnbabyburn()

  const tx = await wallet.contractSend(contractAddress, encodedData, {
    amount: 0.05 * 1e7 // 0.05 SBER in greph
  });

  console.log(tx);
}

main().catch(err => console.log(err));

Networks

Two networks are predefined:

import { networks } from "sbercoinjs-wallet";

// Main Network
networks.mainnet;

// Test Network
networks.testnet;

fromPrivateKey

Alias for fromWIF.

fromWIF

fromWIF constructs a wallet from private key (in WIF format).

Suppose you want to import the public address sg3HYD8c4bAVLeEzA9t3Ken3Y3Mni1HZSS. Use sbercoin-cli to dump the private key from wallet:

qcli dumpprivkey sg3HYD8c4bAVLeEzA9t3Ken3Y3Mni1HZSS

cVHzWuEKUxoRKba9ySZFqUKZ9G5W8NkzthRcPaB65amUJs95RM3d

const network = networks.testnet;

const privateKey = "cVEwiJ5NMTdnkW4ZW2ykUopawtLPXQWtPDmvpTh5jmXYMtg8itAz";

const wallet = network.fromWIF(privateKey);
console.log("public address:", wallet.address);

Output:

public address: sWAnfBnRNhZBqtgSdgHjSfS2D5Jawmafra

fromMnemonic

fromMnemonic constructs a wallet from mnemonic. User can optionally specify a password to add to the mnemonic entropy.

const network = networks.testnet;
const mnemonic =
  "hold struggle ready lonely august napkin enforce retire pipe where avoid drip";
const password = "covfefe";

const wallet = network.fromMnemonic(mnemonic, password);

console.log("public address:", wallet.address);
console.log("private key (WIF):", wallet.toWIF());

Example Output:

public address: sLUHmrFGexxpyHwQphLpE1czZNFE5m1xmV
private key (WIF): cNQKccYYQyGX9G9Qxq2DJev9jHygbZpb2UG7EvUapbtDx5XhkhYE

Wallet

Wallet manages blockchain access for an address. It is able to create and sign transactions locally for sending a payment or interacting with a smart contract.

You would typically construct a Wallet instance using the factory methods provided by Network.

async wallet.getInfo

Get basic information about the wallet address.

Example:

const info = await wallet.getInfo();
console.log(info);

Output:

{ addrStr: 'sbkJZTKQfcout2joWVmnvUrJUDTg93bhdv',
  balance: 128.47960699,
  balanceSat: 12847960699,
  totalReceived: 599.92142295,
  totalReceivedSat: 59992142295,
  totalSent: 471.44181596,
  totalSentSat: 47144181596,
  unconfirmedBalance: 0,
  unconfirmedBalanceSat: 0,
  unconfirmedTxApperances: 0,
  txApperances: 21,
  transactions:
   [ 'd12ff9cfd76836d8eb5a39bc40f1dc5e6e2032bfa132f66cca638a7e76f2b6e7',
     '44fa64f34361cf5460ca116ea396098eb0d20dd43839375c07d69a282d4e29b6',
     'ca86c477bc595f08f158eed0d4307ee6e1e674a2c14f808b013b38cb1e929aa0',
     'fbf41aaca56dd013934471b4630f8ca52a6216cf791701a07f3e5c0ba16902d5',
     'af8fff4a74ff9217d629c17aa84412e8810888983cbc4f6b764740e68b51e5d0',
     'e9172194ef9493a2dd8dddd02aa58a1c13dbfb09a7e04cb97558d951e4b93a88',
     '3e167a2534d5d18b71ba56bbba8bfdb317711b3f2ef30f10d34941ddc9aa4861',
     'bd15b9d9cf4e94915e246a7d78de14cb0a6acec12624902b45717997ef71854e',
     '0c99d68c261dd713819c068bd0213bc048bd4928b3d86d71503bb3348d7f42f5',
     'd5b823bb524862855181d231e716ff86fa301f701fd4c23b68168debe334da2e',
     '7660e89eb45b536b9c7527edafc0884fc2941c0f050625780d3e100c8aeb28f4',
     'eddbbac9bb7dae1cf4093d893133eb52c483b13ea66f6354c63302f9127ec1bd',
     '6f99149d78ad720591b4cca643fe2599a0a07076f8f3e80b5962cba326772e83',
     '0ef2548cceaaa41b7c0127f6e943d103f2fcc236d05e59593e05381f7a8474a0',
     '851753842d80e8dea92de643e0f3784cf7cbdbb02ae879593cbeac2c78560bac',
     '729c839d63f7426a1f4ada7eb5a35b556556665a4b42e102694674551752bb03',
     'ee50d8422dce064d40eb021f4829f5b871e8d2927d93ea136dc0df01b1a72e08',
     'caf8b48b9d38c3a27de3d24c5a738f63ec37619d419cfcd061bc991d8369bda3',
     '3b59444033d61457fe229a866dc9cb4a60a4b070ea3a73cacba27516fd30cee8',
     '5e9ca1c946deaf5458d2b6236145b225eee61ec6991b7df8ee96573b53d82584',
     'cfbadf76884ca661816f25487f6493826579afe257517ebd7d1fc2b0020eb289' ] }

async wallet.send

Send payment to a receiving address. The transaction is signed locally using the wallet's private key, and the raw transaction submitted to a remote API (without revealing the wallet's secret).

Method signature:

/**
 * @param to The receiving address
 * @param amount The amount to transfer (in greph)
 * @return The raw transaction as hexadecimal string
 *
 */
public async send(
  to: string,
  amount: number,
  opts: ISendTxOptions = {},
): Promise<Insight.ISendRawTxResult>

Example:

const toAddress = "sZaTYNEimGLuqnBDpP3KvBKsFs3DbCuwnr";
const amount = 0.15 * 1e7; // 0.15 SBER

const tx = await wallet.send(toAddress, amount);
console.log(tx);

Output:

{ txid: '40fec162e0d4e1377b5e6744eeba562408e22f60399be41e7ba24e1af37f773c' }

async wallet.send options

export interface ISendTxOptions {
  /**
   * Fee rate to pay for the raw transaction data (greph per byte). The
   * default value is the query result of current network's fee rate.
   */
  feeRate?: number;
}

Setting tx fee rate manually:

const tx = await wallet.send(toAddress, amount, {
  // rate is 400 greph per byte, or  ~0.004 SBER/KB, as is typical.
  feeRate: 400
});

async wallet.sendEstimateMaxValue

Estimate the maximum value that could be sent from this wallet address.

const maxSend = await wallet.sendEstimateMaxValue(toAddress);

async wallet.generateTx

Generate and sign a payment transaction.

Method signature:

/**
 * @param to The receiving address
 * @param amount The amount to transfer (in greph)
 * @param opts
 *
 * @returns The raw transaction as hexadecimal string
 */
public async generateTx(
  to: string,
  amount: number,
  opts: ISendTxOptions = {},
): Promise<string>

Example:

const toAddress = "sZaTYNEimGLuqnBDpP3KvBKsFs3DbCuwnr";
const amount = 0.15 * 1e7;

const rawtx = await wallet.generateTx(toAddress, amount);
console.log(rawtx);

Example output, the raw transaction as hexadecimal string:

0100000001a09a921ecb383b018b804fc1a274e6e1e67e30d4d0ee58f1085f59bc77c486ca010000006a47304402202fa6106aca6c682ab89b02ad62614462d1ec5e95cb8b4810ce793ad52a4002590220531cf380368cb8f92c7dd03ee375423073a14e5b7da6f48127c63cab17fbf2d7012103c12c73abaccf35b40454e7eb0c4b5760ce7a720d0cd2c9fb7f5423168aaeea03ffffffff02c0e1e400000000001976a914afb616c886f0efd9a9a486ccc07a09ab8d7a4bb288ac49b6ffe0010000001976a914c78300c58ab7c73e1767e3d550464d591ab0a12888ac00000000

You can decode the raw transaction using sbercoin-cli:

sbercoin-cli decoderawtransaction 0100000001a09a921ecb38...

{
  // ...
  "vout": [
    {
      "value": 0.15000000,
      "n": 0,
      "scriptPubKey": {
        "asm": "OP_DUP OP_HASH160 afb616c886f0efd9a9a486ccc07a09ab8d7a4bb2 OP_EQUALVERIFY OP_CHECKSIG",
        "hex": "76a914afb616c886f0efd9a9a486ccc07a09ab8d7a4bb288ac",
        "reqSigs": 1,
        "type": "pubkeyhash",
        "addresses": [
          "sZaTYNEimGLuqnBDpP3KvBKsFs3DbCuwnr"
        ]
      }
    },
    {
      "value": 80.69822025,
      "n": 1,
      "scriptPubKey": {
        "asm": "OP_DUP OP_HASH160 c78300c58ab7c73e1767e3d550464d591ab0a128 OP_EQUALVERIFY OP_CHECKSIG",
        "hex": "76a914c78300c58ab7c73e1767e3d550464d591ab0a12888ac",
        "reqSigs": 1,
        "type": "pubkeyhash",
        "addresses": [
          "sbkJZTKQfcout2joWVmnvUrJUDTg93bhdv"
        ]
      }
    }
  ]
}

There are two vouts:

1. pubkeyhash 0.15. This is the amount we want to send.
2. pubkeyhash 80.69822025. This is the amount we going back to the original owner as change.

async wallet.contractSend

Create a send-to-contract transaction that invokes a contract's method.

/**
  * @param contractAddress Address of the contract in hexadecimal
  * @param encodedData The ABI encoded method call, and parameter values.
  * @param opts
  */
public async contractSend(
  contractAddress: string,
  encodedData: string,
  opts: IContractSendTXOptions = {},
): Promise<Insight.ISendRawTxResult>

Example:

Invoke the burn() method, and transfer 5000000 greph to the contract.

• The burn() method call ABI encodes to e179b912
• The 5000000 is msg.value in contract code.

const contractAddress = "1620cd3c24b29d424932ec30c5925f8c0a00941c";
// ABI encoded data for the send-to-method transaction
const encodedData = "e179b912";

// Invoke a contract's method, and transferring 0.05 to it.
const tx = await wallet.contractSend(contractAddress, encodedData, {
  amount: 0.05 * 1e7
});

console.log(tx);

Output:

{ txid: 'd12ff9cfd76836d8eb5a39bc40f1dc5e6e2032bfa132f66cca638a7e76f2b6e7' }

async wallet.contractSendEstimateMaxValue

Estimate the maximum value that could be sent to a contract, substracting the amount reserved for gas.

const maxContractSend = await wallet.contractSendEstimateMaxValue(
  contractAddress,
  callDataHex,
  {
    gasLimit: 250000,
    gasPrice: 40
  }
);

async wallet.generateContractSendTx

Generate a raw a send-to-contract transaction that invokes a contract's method.

Method signature:

/**
  * @param contractAddress
  * @param encodedData
  * @param opts
  */
public async generateContractSendTx(
  contractAddress: string,
  encodedData: string,
  opts: IContractSendTXOptions = {},
): Promise<string>

Example:

const contractAddress = "1620cd3c24b29d424932ec30c5925f8c0a00941c";
const encodedData = "e179b912";

const rawtx = await wallet.generateContractSendTx(
  contractAddress,
  encodedData,
  {
    amount: 0.01 * 1e7
  }
);

console.log(rawtx);

Example output:

0100000001e7b6f2767e8a63ca6cf632a1bf32206e5edcf140bc395aebd83668d7cff92fd1010000006b483045022100b86c4cbb2aecab44c951f99c0cbbf6115cf80881b39f33b4efd4d296892c1c15022062db1f681e684616e55303556577c9242102ff7a6815894dfb3090a7928fa13a012103c12c73abaccf35b40454e7eb0c4b5760ce7a720d0cd2c9fb7f5423168aaeea03ffffffff0240420f000000000022540390d003012804e179b912141620cd3c24b29d424932ec30c5925f8c0a00941cc2880256e0010000001976a914c78300c58ab7c73e1767e3d550464d591ab0a12888ac00000000

Decode the raw transaction:

sbercoin-cli decoderawtransaction 0100000001e7b6f2767e8a6...

Decoded Raw TX:

{
  // ...
  "vout": [
    {
      "value": 0.01000000,
      "n": 0,
      "scriptPubKey": {
        "asm": "4 250000 40 314145249 1620cd3c24b29d424932ec30c5925f8c0a00941c OP_CALL",
        "hex": "540390d003012804e179b912141620cd3c24b29d424932ec30c5925f8c0a00941cc2",
        "type": "call"
      }
    },
    {
      "value": 80.58700424,
      "n": 1,
      "scriptPubKey": {
        "asm": "OP_DUP OP_HASH160 c78300c58ab7c73e1767e3d550464d591ab0a128 OP_EQUALVERIFY OP_CHECKSIG",
        "hex": "76a914c78300c58ab7c73e1767e3d550464d591ab0a12888ac",
        "reqSigs": 1,
        "type": "pubkeyhash",
        "addresses": [
          "sbkJZTKQfcout2joWVmnvUrJUDTg93bhdv"
        ]
      }
    }
  ]
}

There are two vouts:

1. call 0.11. This is the amount we want to send to the contract.
2. pubkeyhash 80.58700424. This is the amount we going back to the original owner as change.

async wallet.contractCall

Query a contract's method. It returns the result and logs of a simulated execution of the contract's code.

Method signature:

/**
 * @param contractAddress Address of the contract in hexadecimal
 * @param encodedData The ABI encoded method call, and parameter values.
 * @param opts
 */
public async contractCall(
  contractAddress: string,
  encodedData: string,
  opts: IContractSendTXOptions = {},
): Promise<Insight.IContractCall>

Example:

const contractAddress = "b10071ee33512ce8a0c06ecbc14a5f585a27a3e2";
const encodedData = "e179b912";

const result = await wallet.contractCall(contractAddress, encodedData, {
  amount: 0.01 * 1e7
});

console.log(JSON.stringify(result, null, 2));

Output:

{
  "address": "b10071ee33512ce8a0c06ecbc14a5f585a27a3e2",
  "executionResult": {
    "gasUsed": 27754,
    "excepted": "None",
    "newAddress": "b10071ee33512ce8a0c06ecbc14a5f585a27a3e2",
    "output": "",
    "codeDeposit": 0,
    "gasRefunded": 0,
    "depositSize": 0,
    "gasForDeposit": 0
  },
  "transactionReceipt": {
    "stateRoot": "c04b98dbd1a38be8ecfb71e40072c90a1ee9f5961bb80fa6262f8a32979427bb",
    "gasUsed": 27754,
    "bloom": "000000000000000000002000400000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000000000000000000000000",
    "log": [
      {
        "address": "b10071ee33512ce8a0c06ecbc14a5f585a27a3e2",
        "topics": [
          "9c31339612219a954bda4c790e4b182b6499bdf1464c392cb50e61d8afa1f9f2"
        ],
        "data": "000000000000000000000000ffffffffffffffffffffffffffffffffffffffff0000000000000000000000000000000000000000000000000000000000000000"
      }
    ]
  }
}

getTransactions

Get transactions about the wallet address.

Method signature:

/**
 * get transactions by wallet address
 * @param pageNum page number
 */
public async getTransactions(pageNum?: number): Promise<Insight.IRawTransactions>

Example:

const network = networks.testnet;

const insight = network.insight();

const info = await insight.getTransactionInfo(
  "f20914f3d810010c0a74df60abb3fcf0d3ff2669d944ce187f079ec9faec563e"
);
console.log(info);

Example output:

wallet address: qbkJZTKQfcout2joWVmnvUrJUDTg93bhdv

{
  pagesTotal: 4,
  txs: [
    {
      txid: 'f20914f3d810010c0a74df60abb3fcf0d3ff2669d944ce187f079ec9faec563e',
      version: 1,
      locktime: 0,
      isqrc20Transfer: false,
      vin: [Array],
      vout: [Array],
      blockhash: 'b993b80423233c4371c316e8d2eec6e0ea191efeb518fa3289f8ebce5cec8ab1',
      blockheight: 171321,
      confirmations: 2644,
      time: 1530852864,
      blocktime: 1530852864,
      valueOut: 19.991,
      size: 225,
      valueIn: 20,
      fees: 0.009
    },
    // ...
  ]
}

toEncryptedPrivateKey

encrypted wip using bip38.

Method signature:

/**
 * bip38 encrypted wip
 * @param passphrase
 * @param params scryptParams, default: { N: 16384, r: 8, p: 8 }
 */
public toEncryptedPrivateKey(
  passphrase: string,
  params: {N: number, r: number, p: number} = scryptParams,
): string

Example:

const network = networks.testnet;
const mnemonic =
  "hold struggle ready lonely august napkin enforce retire pipe where avoid drip";
const password = "covfefe";

const wallet = network.fromMnemonic(mnemonic, password);

console.log("public address:", wallet.address);
console.log("private key (WIF):", wallet.toWIF());
console.log(
  "encrypted bip38 private key is:",
  wallet.toEncryptedPrivateKey(password)
);

Example output:

public address: sLUHmrFGexxpyHwQphLpE1czZNFE5m1xmV
private key (WIF): cNQKccYYQyGX9G9Qxq2DJev9jHygbZpb2UG7EvUapbtDx5XhkhYE
encrypted bip38 private key is: 6PYVKJXXQ7eyTgGizw9NxX4nz1u185GqF28NWudxvyWZUh8QyJ9u2AqxWM
encryption takes 2.214 seconds

fromEncryptedPrivateKey

fromEncryptedPrivateKey constructs a wallet from bip38 encrypted private key.

Method signature:

 /**
 * constructs a wallet from bip38 encrypted private key
 * @param encrypted private key string
 * @param passhprase password
 * @param params scryptParams, default: { N: 16384, r: 8, p: 8 }
 */
public fromEncryptedPrivateKey(
  encrypted: string,
  passhprase: string,
  params: {N: number, r: number, p: number} = scryptParams,
): Wallet

Example:

const network = networks.testnet;
const encrypted = "6PYVKJXXQ7eyTgGizw9NxX4nz1u185GqF28NWudxvyWZUh8QyJ9u2AqxWM";
const password = "covfefe";

const startAt = new Date().getTime();
const wallet = network.fromEncryptedPrivateKey(encrypted, password);
const endAt = new Date().getTime();

console.log("public address:", wallet.address);
console.log("private key (WIF):", wallet.toWIF());
console.log(`decryption takes ${(endAt - startAt) / 1000} seconds`);

Example output:

public address: sLUHmrFGexxpyHwQphLpE1czZNFE5m1xmV
private key (WIF): cNQKccYYQyGX9G9Qxq2DJev9jHygbZpb2UG7EvUapbtDx5XhkhYE
decryption takes 2.258 seconds

deriveChildWallet

Use BIP32 to derive child wallets from the current wallet's keypair.

Example:

Generate as many child wallets as you need:

const childWallet0 = wallet.deriveChildWallet(0);
const childWallet1 = wallet.deriveChildWallet(1);

Or omit the child wallet index (defaults to 0):

// The default child wallet index is 0
const childWallet = wallet.deriveChildWallet();

scrypt (non-stable API)

This is an scrypt helper function, which may be removed in the future.

To use scrypt to hash a secret:

import { scrypt } from "sbercoinjs-wallet";

// by default, the bip38 scrypt parameters are used
const hash = scrypt("my secret", {
  progress: status => {
    console.log("status", status);
  }
});

console.log(hash);

The progress callback is invoked every 1000 rounds. And finally the result hash is a hex string.

status { current: 257000, total: 262144, percent: 98.0377197265625 }
status { current: 258000, total: 262144, percent: 98.419189453125 }
status { current: 259000, total: 262144, percent: 98.8006591796875 }
status { current: 260000, total: 262144, percent: 99.18212890625 }
status { current: 261000, total: 262144, percent: 99.5635986328125 }
status { current: 262000, total: 262144, percent: 99.945068359375 }

8b41dd9e92490b8f2b01cbe1f20e2c57315b5f861da1ede1002bc544d90f7e56

You may also choose to specify your own scrypt parameters:

import { scrypt, params } from "sbercoinjs-wallet";

const hash = scrypt("my secret", {
  params: {
    N: 1 << 14,
    r: 8,
    p: 1
  }
});