@instructure/canvas-rce/es/util/encrypted-storage.js

A component wrapping Canvas's usage of Tinymce

/*
 * Copyright (C) 2023 - present Instructure, Inc.
 *
 * This file is part of Canvas.
 *
 * Canvas is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the Free
 * Software Foundation, version 3 of the License.
 *
 * Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

import CryptoES from 'crypto-es';
export default class EncryptedStorage {
  constructor(passphrase) {
    this.passphrase = void 0;
    this.errorHandlerWrapper = callback => {
      try {
        return callback();
      } catch (error) {
        console.error('error', error);
        return null;
      }
    };
    this.passphrase = CryptoES.enc.Utf8.parse(passphrase);
  }
  setItem(key, content) {
    return this.errorHandlerWrapper(() => {
      // If passphrase is present, encrypt string and JSON stringify
      let encrypted;
      if (this.passphrase) {
        encrypted = CryptoES.RC4.encrypt(content, this.passphrase, {
          mode: CryptoES.mode.CFB,
          padding: CryptoES.pad.AnsiX923
        }).toString();
      }
      const data = JSON.stringify({
        autosaveTimestamp: new Date().getTime(),
        content: encrypted
      });
      return window.localStorage.setItem(key, data);
    });
  }
  getItem(key) {
    return this.errorHandlerWrapper(() => {
      const data = window.localStorage.getItem(key);
      if (!data) {
        return data;
      }
      // If passphrase is present, parse JSON and decrypt string
      if (this.passphrase) {
        const parsedData = JSON.parse(data);
        parsedData.content = CryptoES.RC4.decrypt(parsedData.content, this.passphrase, {
          mode: CryptoES.mode.CFB,
          padding: CryptoES.pad.AnsiX923
        });
        parsedData.content = parsedData.content.toString(CryptoES.enc.Utf8);
        return parsedData;
      }
    });
  }
  key(index) {
    return this.errorHandlerWrapper(() => window.localStorage.key(index));
  }
  removeItem(key) {
    return this.errorHandlerWrapper(() => window.localStorage.removeItem(key));
  }
}