standard-ecies

standard-ecies

Standard ECIES (ecc encryption) implemention for NodeJS based on crypto module with no other dependencies.

Motivation

I have tried most of ECIES implemention published on npm, but none of them is exactly what I wanted. sjcl and secp256k1 are not friendly for windows users when compiling their code, so the projects based on them like eccjs and eccrypto are not easy for windows users, either. bitcore-ecies is friendly for windows but its implemention is customized for author's own purpose, not widely applicable.

Implementation

The implemention is followed by the description in https://en.wikipedia.org/wiki/Integrated_Encryption_Scheme .

Support all of curves listed in crypto.getCurves().

Usage

const crypto = require('crypto');
const ecies = require('standard-ecies');

// option parameter is optional, all options are optional except iv,
// when symmetric cipher is not in ecb mode, iv option must be offered. 

// default options
var options = {
    hashName: 'sha256',
    hashLength: 32,
    macName: 'sha256',
    macLength: 32,
    curveName: 'secp256k1',
    symmetricCypherName: 'aes-256-ecb',
    iv: null, // iv is used in symmetric cipher, set null if cipher is in ECB mode. 
    keyFormat: 'uncompressed',
    s1: null, // optional shared information1
    s2: null // optional shared information2
}
var ecdh = crypto.createECDH(options.curveName);
ecdh.generateKeys();

var plainText = new Buffer('hello world');
var encryptedText = ecies.encrypt(ecdh.getPublicKey(), plainText, options);
var decryptedText = ecies.decrypt(ecdh, encryptedText, options);
assert(plainText.toString('hex') == decryptedText.toString('hex'));