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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.deriveKeys = deriveKeys;
/*
* Copyright 2024 The Matrix.org Foundation C.I.C.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// salt for HKDF, with 8 bytes of zeros
const zeroSalt = new Uint8Array(8);
/**
* Derive AES and HMAC keys from a master key.
*
* This is used for deriving secret storage keys: see https://spec.matrix.org/v1.11/client-server-api/#msecret_storagev1aes-hmac-sha2 (step 1).
*
* @param key
* @param name
*/
async function deriveKeys(key, name) {
const hkdfkey = await globalThis.crypto.subtle.importKey("raw", key, {
name: "HKDF"
}, false, ["deriveBits"]);
const keybits = await globalThis.crypto.subtle.deriveBits({
name: "HKDF",
salt: zeroSalt,
// eslint-disable-next-line @typescript-eslint/ban-ts-comment
info: new TextEncoder().encode(name),
hash: "SHA-256"
}, hkdfkey, 512);
const aesKey = keybits.slice(0, 32);
const hmacKey = keybits.slice(32);
const aesProm = globalThis.crypto.subtle.importKey("raw", aesKey, {
name: "AES-CTR"
}, false, ["encrypt", "decrypt"]);
const hmacProm = globalThis.crypto.subtle.importKey("raw", hmacKey, {
name: "HMAC",
hash: {
name: "SHA-256"
}
}, false, ["sign", "verify"]);
return Promise.all([aesProm, hmacProm]);
}