eth-crypto/src/encrypt-with-public-key.js

Cryptographic functions for ethereum and how to use them with web3 and solidity

import {
    encrypt
} from 'eccrypto';
import {
    decompress
} from './public-key';

export function encryptWithPublicKey(publicKey, message, opts) {

    // ensure its an uncompressed publicKey
    publicKey = decompress(publicKey);

    // re-add the compression-flag
    const pubString = '04' + publicKey;


    return encrypt(
        Buffer.from(pubString, 'hex'),
        Buffer.from(message),
        opts ? opts : {}
    ).then(encryptedBuffers => {
        const encrypted = {
            iv: encryptedBuffers.iv.toString('hex'),
            ephemPublicKey: encryptedBuffers.ephemPublicKey.toString('hex'),
            ciphertext: encryptedBuffers.ciphertext.toString('hex'),
            mac: encryptedBuffers.mac.toString('hex')
        };
        return encrypted;
    });
}