Diffie-Hellman encryption

@webbuf/aesgcm-p256dh

AES-GCM authenticated encryption with P-256 (NIST) Diffie-Hellman shared secret

Install

npm install @webbuf/aesgcm-p256dh

Usage

import { aesgcmP256dhEncrypt, aesgcmP256dhDecrypt } from "@webbuf/aesgcm-p256dh";
import { p256PublicKeyCreate } from "@webbuf/p256";
import { WebBuf } from "@webbuf/webbuf";
import { FixedBuf } from "@webbuf/fixedbuf";

// Alice and Bob generate key pairs
const alicePrivKey = FixedBuf.fromRandom<32>(32);
const alicePubKey = p256PublicKeyCreate(alicePrivKey);

const bobPrivKey = FixedBuf.fromRandom<32>(32);
const bobPubKey = p256PublicKeyCreate(bobPrivKey);

// Alice encrypts a message to Bob
const plaintext = WebBuf.fromUtf8("Hello Bob!");
const ciphertext = aesgcmP256dhEncrypt(alicePrivKey, bobPubKey, plaintext);

// Bob decrypts the message from Alice
const decrypted = aesgcmP256dhDecrypt(bobPrivKey, alicePubKey, ciphertext);
console.log(decrypted.toUtf8()); // "Hello Bob!"

API reference (2 exports)

Functions

aesgcmP256dhDecrypt

function

Use Alice's private key and Bob's public key to derive a shared secret (Diffie-Hellman with P-256) and use that shared secret as the decryption key for AES-GCM decryption.

aesgcmP256dhDecrypt(alicePrivKey: FixedBuf<32>, bobPubKey: FixedBuf<33>, ciphertext: WebBuf): WebBuf

aesgcmP256dhEncrypt

function

Use Alice's private key and Bob's public key to derive a shared secret (Diffie-Hellman with P-256) and use that shared secret as the encryption key for AES-GCM encryption. Key derivation: SHA-256(P-256-ECDH(privKey, pubKey)) -> 32-byte AES-256-GCM key

aesgcmP256dhEncrypt(alicePrivKey: FixedBuf<32>, bobPubKey: FixedBuf<33>, plaintext: WebBuf, iv?: FixedBuf<12>): WebBuf