Overview

The CryptoApi class provides a set of cryptographic functions that can be used to generate keys, sign data, encrypt/decrypt data, and more. This documentation will guide you through some common use cases, such as generating a private and public key pair, implementing a login flow using signatures, and other cryptographic operations.

Getting Started

To use the CryptoApi class, you first need to import and instantiate it:

import { Endpoint } from '@simplito/privmx-webendpoint';

const cryptoApi = await Endpoint.createCryptoApi();

Generating Private and Public Key Pair

You can generate a private and public key pair using a login and password. The private key is derived from the password and a salt, while the public key is derived from the private key.

const login = "EXAMPLE_LOGIN";
const password = "EXAMPLE_PASSWORD";
const salt = "EXAMPLE_SALT";

// Derive the private key from the password and salt
const privateKey = await cryptoApi.derivePrivateKey2(password, salt);

// Derive the public key from the private key
const publicKey = await cryptoApi.derivePublicKey(privateKey);

console.log("Private Key:", privateKey);
console.log("Public Key:", publicKey);

Login Flow Using Signature Verification

In a typical login flow, the client signs a challenge (e.g., a random string) using their private key, and the server verifies the signature using the corresponding public key.

// Assume the server sends a challenge to the client
const challenge = Buffer.from("RANDOM_CHALLENGE_STRING");

// Sign the challenge using the private key
const signature = await cryptoApi.signData(challenge, privateKey);

// Send the signature and public key to the server for verification
const loginData = {
    publicKey: publicKey,
    signature: signature
};

// Send loginData to the server

Encrypting and Decrypting Data

You can use the CryptoApi to encrypt and decrypt data using symmetric keys.

const data = new TextEncoder().encode("Sensitive data to encrypt");

// Generate a symmetric key
const symmetricKey = await cryptoApi.generateKeySymmetric();

// Encrypt the data
const encryptedData = await cryptoApi.encryptDataSymmetric(data, symmetricKey);

console.log("Encrypted Data:", encryptedData);

Additional Use Cases

Converting PEM Key to WIF Format

If you have a private key in PEM format, you can convert it to WIF format using the convertPEMKeytoWIFKey method:

const pemKey = "-----BEGIN PRIVATE KEY-----\n...\n-----END PRIVATE KEY-----";
const wifKey = await cryptoApi.convertPEMKeytoWIFKey(pemKey);

console.log("WIF Key:", wifKey);

Generating a Random Private Key

You can generate a random private key without using a password or salt.

const privateKey = await cryptoApi.generatePrivateKey();
console.log("Random Private Key:", privateKey);