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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = decryptAESSecretStorageItem;
var _base = require("../base64.js");
var _deriveKeys = require("./internal/deriveKeys.js");
/*
* 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.
*/
/**
* 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}.
*/
async function decryptAESSecretStorageItem(data, key, name) {
const [aesKey, hmacKey] = await (0, _deriveKeys.deriveKeys)(key, name);
const ciphertext = (0, _base.decodeBase64)(data.ciphertext);
if (!(await globalThis.crypto.subtle.verify({
name: "HMAC"
}, hmacKey, (0, _base.decodeBase64)(data.mac), ciphertext))) {
throw new Error(`Error decrypting secret ${name}: bad MAC`);
}
const plaintext = await globalThis.crypto.subtle.decrypt({
name: "AES-CTR",
counter: (0, _base.decodeBase64)(data.iv),
length: 64
}, aesKey, ciphertext);
return new TextDecoder().decode(new Uint8Array(plaintext));
}