43 lines
2.0 KiB
JavaScript
43 lines
2.0 KiB
JavaScript
/*
|
|
* 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
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
import { decodeBase64 } from "../base64.js";
|
|
import { deriveKeys } from "./internal/deriveKeys.js";
|
|
/**
|
|
* Decrypt an AES-encrypted Secret Storage item.
|
|
*
|
|
* @param data - the encrypted data, returned by {@link utils/encryptAESSecretStorageItem.default | encryptAESSecretStorageItem}.
|
|
* @param key - the encryption key to use as an input to the HKDF function which is used to derive the AES key. Must
|
|
* be the same as provided to {@link utils/encryptAESSecretStorageItem.default | encryptAESSecretStorageItem}.
|
|
* @param name - the name of the secret. Also used as an input to the HKDF operation which is used to derive the AES
|
|
* key, so again must be the same as provided to {@link utils/encryptAESSecretStorageItem.default | encryptAESSecretStorageItem}.
|
|
*/
|
|
export default async function decryptAESSecretStorageItem(data, key, name) {
|
|
const [aesKey, hmacKey] = await deriveKeys(key, name);
|
|
const ciphertext = decodeBase64(data.ciphertext);
|
|
if (!(await globalThis.crypto.subtle.verify({
|
|
name: "HMAC"
|
|
}, hmacKey, decodeBase64(data.mac), ciphertext))) {
|
|
throw new Error(`Error decrypting secret ${name}: bad MAC`);
|
|
}
|
|
const plaintext = await globalThis.crypto.subtle.decrypt({
|
|
name: "AES-CTR",
|
|
counter: decodeBase64(data.iv),
|
|
length: 64
|
|
}, aesKey, ciphertext);
|
|
return new TextDecoder().decode(new Uint8Array(plaintext));
|
|
}
|
|
//# sourceMappingURL=decryptAESSecretStorageItem.js.map
|