epir/src_ts/wasm.SelectorFactory.worker.ts

EllipticPIR client library (Node.js / TypeScript bindings).

import { arrayBufferConcat } from './util';
import { SCALAR_SIZE, CIPHER_SIZE } from './types';
import { createLibEpirHelper, LibEpirHelper } from './wasm.libepir';

const worker: Worker = self as unknown as Worker;

const execute = async (
	helper: LibEpirHelper,
	params: { isFast: boolean, key: ArrayBuffer, msg: number, count: number, random: ArrayBuffer }) => {
	const ciphers: ArrayBuffer[] = [];
	const cipher_ = helper.malloc(CIPHER_SIZE);
	const key_ = helper.malloc(params.key);
	const r_ = helper.malloc(SCALAR_SIZE);
	for(let i=0; i<params.count; i++) {
		const encrypt = params.isFast ? 'ecelgamal_encrypt_fast' : 'ecelgamal_encrypt';
		helper.set(params.random, i * SCALAR_SIZE, SCALAR_SIZE, r_);
		helper.call(encrypt, cipher_, key_, params.msg&0xffffffff, Math.floor(params.msg/0x100000000), r_);
		const cipher = helper.slice(cipher_, CIPHER_SIZE);
		ciphers.push(cipher);
	}
	const ciphersConcat = arrayBufferConcat(ciphers);
	worker.postMessage({
		msg: params.msg,
		ciphers: ciphersConcat,
	}, [ciphersConcat]);
	helper.free(cipher_);
	helper.free(key_);
	helper.free(r_);
};

worker.onmessage = async (ev) => {
	execute(await createLibEpirHelper(), ev.data);
};