xsalsa20 instance that works in node and in the browser
npm install xsalsa20-universal
const XSalsa20 = require('xsalsa20-universal')
const x = new XSalsa20(nonce, key)
x.update(output1, input1)
x.update(output2, input2)
x.update(output3, input3)
x.final()MIT