47 lines
1.9 KiB
Plaintext
47 lines
1.9 KiB
Plaintext
import { encoder, concat, uint32be, lengthAndInput, concatKdf } from '../lib/buffer_utils.js';
|
|
import crypto, { isCryptoKey } from './webcrypto.js';
|
|
import { checkEncCryptoKey } from '../lib/crypto_key.js';
|
|
import invalidKeyInput from '../lib/invalid_key_input.js';
|
|
import { types } from './is_key_like.js';
|
|
export async function deriveKey(publicKey, privateKey, algorithm, keyLength, apu = new Uint8Array(0), apv = new Uint8Array(0)) {
|
|
if (!isCryptoKey(publicKey)) {
|
|
throw new TypeError(invalidKeyInput(publicKey, ...types));
|
|
}
|
|
checkEncCryptoKey(publicKey, 'ECDH');
|
|
if (!isCryptoKey(privateKey)) {
|
|
throw new TypeError(invalidKeyInput(privateKey, ...types));
|
|
}
|
|
checkEncCryptoKey(privateKey, 'ECDH', 'deriveBits');
|
|
const value = concat(lengthAndInput(encoder.encode(algorithm)), lengthAndInput(apu), lengthAndInput(apv), uint32be(keyLength));
|
|
let length;
|
|
if (publicKey.algorithm.name === 'X25519') {
|
|
length = 256;
|
|
}
|
|
else if (publicKey.algorithm.name === 'X448') {
|
|
length = 448;
|
|
}
|
|
else {
|
|
length =
|
|
Math.ceil(parseInt(publicKey.algorithm.namedCurve.substr(-3), 10) / 8) << 3;
|
|
}
|
|
const sharedSecret = new Uint8Array(await crypto.subtle.deriveBits({
|
|
name: publicKey.algorithm.name,
|
|
public: publicKey,
|
|
}, privateKey, length));
|
|
return concatKdf(sharedSecret, keyLength, value);
|
|
}
|
|
export async function generateEpk(key) {
|
|
if (!isCryptoKey(key)) {
|
|
throw new TypeError(invalidKeyInput(key, ...types));
|
|
}
|
|
return crypto.subtle.generateKey(key.algorithm, true, ['deriveBits']);
|
|
}
|
|
export function ecdhAllowed(key) {
|
|
if (!isCryptoKey(key)) {
|
|
throw new TypeError(invalidKeyInput(key, ...types));
|
|
}
|
|
return (['P-256', 'P-384', 'P-521'].includes(key.algorithm.namedCurve) ||
|
|
key.algorithm.name === 'X25519' ||
|
|
key.algorithm.name === 'X448');
|
|
}
|