qortal-ui/crypto/api/transactions/arbitrary/signArbitrary.js

import nacl from '../../deps/nacl-fast'
import utils from '../../deps/utils'
import Base58 from '../../deps/Base58'

const signArbitrary = (arbitraryBytesBase58, arbitraryBytesForSigningBase58, nonce, keyPair) => {
	if (!arbitraryBytesBase58) {
		throw new Error('ArbitraryBytesBase58 not defined')
	}

	if (!nonce) {
		throw new Error('Nonce not defined')
	}

	if (!keyPair) {
		throw new Error('keyPair not defined')
	}

	const arbitraryBytes = Base58.decode(arbitraryBytesBase58)
	const _arbitraryBytesBuffer = Object.keys(arbitraryBytes).map(function (key) { return arbitraryBytes[key]; })
	const arbitraryBytesBuffer = new Uint8Array(_arbitraryBytesBuffer)
	const arbitraryBytesForSigning = Base58.decode(arbitraryBytesForSigningBase58)
	const _arbitraryBytesForSigningBuffer = Object.keys(arbitraryBytesForSigning).map(function (key) { return arbitraryBytesForSigning[key]; })
	const arbitraryBytesForSigningBuffer = new Uint8Array(_arbitraryBytesForSigningBuffer)
	const _nonce = utils.int32ToBytes(nonce)

	arbitraryBytesBuffer.set(_nonce, 112)
	arbitraryBytesForSigningBuffer.set(_nonce, 112)

	const signature = nacl.sign.detached(arbitraryBytesForSigningBuffer, keyPair.privateKey)

	return utils.appendBuffer(arbitraryBytesBuffer, signature)
}

export default signArbitrary