ecies-25519 
Isomorphic Cryptography Library for X25519 ECIES
Description
This library supports ECIES encryption using Curve25519 Diffie–Hellman key exchange (aka X25519).
AES, HMAC and SHA methods are supported through native NodeJS and Browser APIs when available and fallbacks to vanilla javascript are already provided.
Usage
ECIES
import * as ecies25519 from 'ecies-25519';
import * as encUtils from 'enc-utils';
const keyPair = ecies25519.generateKeyPair();
const str = 'test message to encrypt';
const msg = encUtils.utf8ToArray(str);
const encrypted = await ecies25519.encrypt(msg, keyPairB.publicKey);
const decrypted = await ecies25519.decrypt(encrypted, keyPairB.privateKey);
// decrypted === msgECDH
import * as ecies25519 from 'ecies-25519';
const keyPairA = ecies25519.generateKeyPair();
const keyPairB = ecies25519.generateKeyPair();
const sharedKey1 = await ecies25519.derive(
keyPairA.privateKey,
keyPairB.publicKey
);
const sharedKey2 = await ecies25519.derive(
keyPairB.privateKey,
keyPairA.publicKey
);
// sharedKey1 === sharedKey2RandomBytes
import * as ecies25519 from 'ecies-25519';
const length = 32;
const key = ecies25519.randomBytes(length);
// key.length === lengthAES
import * as ecies25519 from 'ecies-25519';
import * as encUtils from 'enc-utils';
const key = ecies25519.randomBytes(32);
const iv = ecies25519.randomBytes(16);
const str = 'test message to encrypt';
const msg = encUtils.utf8ToArray(str);
const ciphertext = await ecies25519.aesCbcEncrypt(iv, key, msg);
const decrypted = await ecies25519.aesCbcDecrypt(iv, key, ciphertext);
// decrypted === strHMAC
import * as ecies25519 from 'ecies-25519';
import * as encUtils from 'enc-utils';
const key = ecies25519.randomBytes(32);
const iv = ecies25519.randomBytes(16);
const macKey = encUtils.concatArrays(iv, key);
const dataToMac = encUtils.concatArrays(iv, key, msg);
const mac = await ecies25519.hmacSha256Sign(macKey, dataToMac);
const result = await ecies25519.hmacSha256Verify(macKey, dataToMac, mac);
// result will return true if matchSHA2
import * as ecies25519 from 'ecies-25519';
import * as encUtils from 'enc-utils';
// SHA256
const str = 'test message to hash';
const msg = encUtils.utf8ToArray(str);
const hash = await ecies25519.sha256(str);
// SHA512
const str = 'test message to hash';
const msg = encUtils.utf8ToArray(str);
const hash = await ecies25519.sha512(str);React-Native Support
This library is intended for use in a Browser or NodeJS environment, however it is possible to use in a React-Native environment if NodeJS modules are polyfilled with react-native-crypto, read more here.