gocrypto/src/index.js

Cryption library based on Go-WebAssembly

'use strict'; 

const fs = require('fs');
const _ = require('../lib/wasm_exec.js');
const { generateKey, sign, getPublicKey, verify } = require('./key.js');

(generator => {
    if (typeof exports === 'object') {
        const crypto = require('crypto')
        crypto.getRandomValues = crypto.randomFillSync
        generator(exports, true)
    } else {
        const exports = {};
        window.gocrypto = generator(exports, false)
    }
  })((exports, isNodeJs) => {

    var _isInitialized = false;

    exports.isInitialized = () => {
        return _isInitialized;
    }

    exports.init = () => {
        return new Promise((resolve, reject) => {
            if (_isInitialized) {
                console.log("gocrypto already initialized!")
                resolve();
                return;
            }
            if (WebAssembly) {
                // WebAssembly.instantiateStreaming is not currently available in Safari
                if (WebAssembly && !WebAssembly.instantiateStreaming) { // polyfill
                    WebAssembly.instantiateStreaming = async (resp, importObject) => {
                        var source = resp;
                        if (!isNodeJs) {
                            source = await (await resp).arrayBuffer();
                        }
                        return await WebAssembly.instantiate(source, importObject);
                    };
                } 

                // Initialize g.__gobridge__ as the binded object of wasm
                const g = global || window || self;
                if (!g.__gobridge__) {
                    g.__gobridge__ = {};
                }

                const go = new Go();
                var wasmInitPromise;
                 
                if (isNodeJs) {
                    wasmInitPromise = fs.promises.readFile("./bin/DMSGoCrypto.wasm")
                    .then(data => {
                        return WebAssembly.instantiateStreaming(data, go.importObject)
                    })
                } else {
                    wasmInitPromise = WebAssembly.instantiateStreaming(fetch("./bin/DMSGoCrypto.wasm"), go.importObject)
                }
                wasmInitPromise.then((result) => {
                    go.run(result.instance);
                    _isInitialized = true;
                    resolve()
                }).catch( error => {
                    return reject(error);
                });
            } else {
                reject("WebAssembly is not supported in your browser");
            }
        });
    }

    exports.generateKey = generateKey;
    exports.sign = sign;
    exports.getPublicKey = getPublicKey;
    exports.verify = verify;

    return exports;
  })