Wallet Module

This module provides functionalities to manage BandChain account. It can be used to create a private key from mnemonic, sign and verify signature, and account address manipulation.

PrivateKey

A class for wrapping signing key, which is a byte array of private key, used for signature creation and public key derivation.

generate(path)

A static method for generating new private key with random mnemonic phrase.

info

If path is not given, default to Band's HD prefix 494 and all other indexes being zeroes.

Parameter

• path string - The HD path that follows the BIP32 standard (optional)

Return

• [string, PrivateKey] - A tuple of mnemonic phrase and [PrivateKey] instance

Exception

Type	Description
CreateError	Cannot create private key

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PrivateKey } = Wallet
const [mnemonic, priv] = PrivateKey.generate("m/44'/494'/0'/0/3")

---

fromMnemonic(word, path)

A static method for creating a [PrivateKey] instance from a given mnemonic phrase and a HD derivation path.

info

If path is not given, default to Band's HD prefix 494 and all other indexes being zeroes.

Parameter

• words string - The mnemonic phrase for recover private key
• path string - The HD path that follows the BIP32 standard (optional)

Return

• [PrivateKey] - Initialized PrivateKey object

Exception

Type	Description
CreateError	Cannot create private key

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PrivateKey } = Wallet
const priv = PrivateKey.fromMnemonic('test mnemonic')

---

fromHex(priv)

Create a [PrivateKey] instance from a given a hex representation of signing key.

Parameter

• priv string - A hex representation of signing key.

Return

• [PrivateKey] - Initialized PrivateKey object

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PrivateKey } = Wallet
const priv = PrivateKey.fromHex('2442b724db7189468f16accc0fc505f0609817eb129e13702e696d8b84609ea9')

---

toHex

Return a hex representation of signing key.

Return

• string - A hex representation of signing key.

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PrivateKey } = Wallet
const priv = PrivateKey.fromMnemonic('test mnemonic')
console.log(priv.toHex())

Result

2cb2e2d3582cebf0664d9cda0b89c5d478ae12fac19a6f4ed9c10a7406a19615

---

toPubkey

Create a [PublicKey] instance which is associated with given private key.

Return

• [PublicKey] - A PublicKey that can be used to verify the signatures made with this PrivateKey.

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PrivateKey } = Wallet
const priv = PrivateKey.fromMnemonic('test mnemonic')
console.log(priv.toPubkey().toHex())

Result

02b2b0d35cb1c6d3923813c64e46a82d29e12d03288f438b9d3cf232d9a22bcb83

---

sign(msg)

Sign and the given bytes array.

Parameter

• msg Buffer - The message that will be hashed and signed.

Return

• Buffer - A signature of this private key over the given message

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PrivateKey } = Wallet
const priv = PrivateKey.fromMnemonic('test mnemonic')
console.log(priv.sign(Buffer.from('test message')).toString('hex'))

Result

4bbc9a7ea54b47b11c67a4074e8d9bca068cb64c788f67342c4033b1b6f0553e1bc63cdf9bc2fb6e89c1e965c1e0f0712a51c250627282309cd2fccf1470f4f6

---

PublicKey

Class for wraping verify Key, which is a byte array of public key, used for signature verification, and generate bech32-encoded address.

fromAccBech32(bech)

Creates a [PublicKey] instance from a bech32-encoded public key with account-pubkey prefix.

Parameter

• bech string - A bech32-encoded with account public key prefix.

Return

• [PublicKey] - A PublicKey instance

Exception

Type	Description
ValueError	Invalid bech32 prefix
DecodeError	Cannot decode bech32

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromAccBech32(
  'bandpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6mw8s9v'
)

---

fromValBech32(bech)

Creates a [PublicKey] instance from a bech32-encoded public key with validator-pubkey prefix

Parameter

• bech string - A bech32-encoded with validator public key prefix

Return

• [PublicKey] - A PublicKey instance

Exception

Type	Description
ValueError	Invalid bech32 prefix
DecodeError	Cannot decode bech32

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromValBech32(
  'bandvaloperpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q69gsm29'
)

---

fromConsBech32(bech)

Creates a [PublicKey] instance from a bech32-encoded public key with validator-consensus-pubkey prefix

Parameter

• bech string A bech32-encoded with validator consensus public key prefix

Return

• [PublicKey] - A PublicKey instance

Exception

Type	Description
ValueError	Invalid bech32 prefix
DecodeError	Cannot decode bech32

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromConsBech32(
  'bandvalconspub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6r8ytws'
)

---

toHex

Returns a hex representation of verifying key.

Return

• string - A hex representation of verifying key.

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromAccBech32(
  'bandpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6mw8s9v'
)
console.log(publickey.toHex())

Result

0351e98e1be097250f2ff4188c0aace0a716e69a992cd77f9dfe436b3e8b34280d

---

toPubkeyProto

Returns an instance of Cosmos SDK Protobuf's [PubKey], which can be used for constructing transactions.

Return

• [PubKey] - An instance of Cosmos SDK Protobuf's PubKey

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromAccBech32(
  'bandpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6mw8s9v'
)
// Converting to base64 is for displaying only
console.log(publickey.toPubkeyProto().getKey_asB64())

Result

A1HpjhvglyUPL/QYjAqs4KcW5pqZLNd/nf5Daz6LNCgN

---

toAccBech32

Returns bech32-encoded public key with account-pubkey prefix

Return

• string - A bech32-encoded with account public key prefix.

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromAccBech32(
  'bandpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6mw8s9v'
)
console.log(publickey.toAccBech32())

Result

bandpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6mw8s9v

---

toValBech32

Returns bech32-encoded public key with validator-pubkey prefix

Return

• string - A bech32-encoded with validator public key prefix.

Exceptions

Type	Description
UnsuccessfulCallError	Unsuccessful bech32.toWords call

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromAccBech32(
  'bandpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6mw8s9v'
)
console.log(publickey.toValBech32())

Result

bandvaloperpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q69gsm29

---

toConsBech32

Returns bech32-encoded public key with validator-consensus-pubkey prefix

Return

• string - A bech32-encoded with validator consensus public key prefix.

Exceptions

Type	Description
UnsuccessfulCallError	Unsuccessful bech32.toWords call

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromAccBech32(
  'bandpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6mw8s9v'
)
console.log(publickey.toConsBech32())

Result

bandvalconspub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6r8ytws

---

toAddress

Returns an [Address] instance from given public key

Return

• [Address] - An Address instance.

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PublicKey } = Wallet
const publickey = PublicKey.fromAccBech32(
  'bandpub1addwnpepqdg7nrsmuztj2re07svgcz4vuzn3de56nykdwlualepkk05txs5q6mw8s9v'
)
console.log(publickey.toAddress().toHex())

Result

8e453e66fb009b119ea9b1b8775be6fa9435013b

---

verify(msg, sig)

Verify a signature made over provided data.

Parameter

• msg Buffer A data signed by the signature, will be hashed using sha256 function
• sig Buffer A encoding of the signature

Return

• boolean True if the verification was successful

Exception

Type	Description
BadSignatureError	if the signature is invalid or malformed

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { PrivateKey } = Wallet
const priv = PrivateKey.fromMnemonic('test mnemonic')
const pubkey = priv.toPubkey()
const msg = Buffer.from('test message')
const sig = priv.sign(msg)
console.log(pubkey.verify(msg, sig))

Result

true

---

Address

Class for wraping Address. Adding method to encode/decode to Bech32 format.

fromAccBech32(bech)

Create an [Address] instance from a bech32-encoded with account prefix.

Parameter

• bech string - A bech32-encoded with account prefix.

Return

• [Address] - A Address instance

Exception

Type	Description
ValueError	Invalid bech32 prefix
DecodeError	Cannot decode bech32

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Address } = Wallet
const address = Address.fromAccBech32('band13eznuehmqzd3r84fkxu8wklxl22r2qfmtlth8c')

---

fromValBech32(bech)

Create an [Address] instance from a bech32-encoded with validator prefix

Parameter

• bech string - A bech32-encoded with validator prefix

Return

• [Address] - A Address instance

Exception

Type	Description
ValueError	Invalid bech32 prefix
DecodeError	Cannot decode bech32

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Address } = Wallet
const address = Address.fromValBech32('bandvaloper13eznuehmqzd3r84fkxu8wklxl22r2qfm8f05zn')

---

fromConsBech32(bech)

Create an [Address] instance from a bech32-encoded with validator consensus prefix

Parameter

• bech string - A bech32-encoded with validator consensus prefix

Return

• [Address] - A Address instance

Exception

Type	Description
ValueError	Invalid bech32 prefix
DecodeError	Cannot decode bech32

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Address } = Wallet
const address = Address.fromConsBech32('bandvalcons13eznuehmqzd3r84fkxu8wklxl22r2qfmn6ugwj')

---

toHex

Return a hex representation of Address.

Return

• string - A hex representation of Address.

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Address } = Wallet
const address = Address.fromAccBech32('band13eznuehmqzd3r84fkxu8wklxl22r2qfmtlth8c')
console.log(address.toHex())

Result

8e453e66fb009b119ea9b1b8775be6fa9435013b

---

toAccBech32

Return bech32-encoded with account prefix

Return

• string - A bech32-encoded with account prefix.

Exceptions

Type	Description
UnsuccessfulCallError	Unsuccessful bech32.toWords call

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Address } = Wallet
const address = Address.fromAccBech32('band13eznuehmqzd3r84fkxu8wklxl22r2qfmtlth8c')
console.log(address.toAccBech32())

Result

band13eznuehmqzd3r84fkxu8wklxl22r2qfmtlth8c

---

toValBech32

Return bech32-encoded with validator prefix

Return

• string A bech32-encoded with validator prefix.

Exceptions

Type	Description
UnsuccessfulCallError	Unsuccessful bech32.toWords call

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Address } = Wallet
const address = Address.fromAccBech32('band13eznuehmqzd3r84fkxu8wklxl22r2qfmtlth8c')
console.log(address.toValBech32())

Result

bandvaloper13eznuehmqzd3r84fkxu8wklxl22r2qfm8f05zn

---

toConsBech32

Return bech32-encoded with validator consensus prefix

Return

• string - A bech32-encoded with validator consensus prefix.

Exceptions

Type	Description
UnsuccessfulCallError	Unsuccessful bech32.toWords call

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Address } = Wallet
const address = Address.fromAccBech32('band13eznuehmqzd3r84fkxu8wklxl22r2qfmtlth8c')
console.log(address.toConsBech32())

Result

bandvalcons13eznuehmqzd3r84fkxu8wklxl22r2qfmn6ugwj

---

Ledger

Ledger is a fundamental class that allows you to interact and perform actions with your Ledger devices; signing, and obtaining the account address.

connectLedgerNode(hdPath)

A static method used to connect Ledger with Node HID implementation.

Parameter

• hdPath <string> - The HD path that follows the BIP32 standard (optional). Defaults to m/44'/118'/0'/0/0 if not provided.

Return

• <Ledger>: Ledger object.

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Ledger } = Wallet

const connectLedger = async () => {
  const ledger = await Ledger.connectLedgerNode("m/44'/118'/0'/0/0")
  console.log(ledger)
}

;(async () => {
  await connectLedger()
})()

connectLedgerWeb(hdPath)

A static method used to connect Ledger with WebUSB/WebHID protocol implementation.

Parameter

• hdPath <string> - The HD path that follows the BIP32 standard (optional). Defaults to m/44'/118'/0'/0/0 if not provided.

Return

• <Ledger>: Ledger object.

import { Wallet } from '@bandprotocol/bandchain.js'

const { Ledger } = Wallet

const connectLedger = async () => {
  const ledger = await Ledger.connectLedgerWeb("m/44'/118'/0'/0/0")
  console.log(ledger)
}

;(async () => {
  await connectLedger()
})()

getPubKeyAndBech32Address

This function returns public key and bech32 address with band prefix of the associated Ledger.

Return

An object containing public key and bech32 address with the following keys

• bech32_address <string>
• pubKey <PublicKey>

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Ledger } = Wallet

;(async () => {
  const ledger = await Ledger.connectLedgerWeb("m/44'/118'/0'/0/0")
  const addressObject = await ledger.getPubKeyAndBech32Address()
  console.log(addressObject)
})()

Return

{
    bech32_address: "band1pxzqj53rg87e2n0swh8h7a6m2umjlja6uwffp9",
    pubKey: PublicKey {verifyKey: Uint8Array(33)}
}

sign(transaction)

This function returns the signature of the associated Ledger. The message is signed by using the Nano App signTransaction function.

Parameter

• transaction <Transaction>: Sign message will be extracted from Transaction class and signed.

Return

• <Buffer>: A signature of the connected ledger over the given Transaction message.

Example in Bandchain.js Basic Usage

disconnect

As its namesake dictates, this function will disconnect the Ledger device.

Example

import { Wallet } from '@bandprotocol/bandchain.js'

const { Ledger } = Wallet

;(async () => {
  const ledger = await Ledger.connectLedgerWeb("m/44'/118'/0'/0/0")
  await ledger.disconnect()
})()