pdf.js/web/generic_signature_storage.js

77 lines
1.9 KiB
JavaScript

/* Copyright 2025 Mozilla Foundation
*
* 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 { getUuid } from "pdfjs-lib";
class SignatureStorage {
// TODO: Encrypt the data in using a password and add a UI for entering it.
// We could use the Web Crypto API for this (see https://bradyjoslin.com/blog/encryption-webcrypto/
// for an example).
#signatures = null;
#save() {
localStorage.setItem("pdfjs.signature", JSON.stringify(this.#signatures));
}
async getAll() {
if (!this.#signatures) {
const data = localStorage.getItem("pdfjs.signature");
this.#signatures = data ? JSON.parse(data) : Object.create(null);
}
return this.#signatures;
}
async isFull() {
return Object.keys(await this.getAll()).length === 5;
}
async create(data) {
if (await this.isFull()) {
return null;
}
const uuid = getUuid();
this.#signatures[uuid] = data;
this.#save();
return uuid;
}
async delete(uuid) {
const signatures = await this.getAll();
if (!signatures[uuid]) {
return false;
}
delete signatures[uuid];
this.#save();
return true;
}
async update(uuid, data) {
const signatures = await this.getAll();
const oldData = signatures[uuid];
if (!oldData) {
return false;
}
Object.assign(oldData, data);
this.#save();
return true;
}
}
export { SignatureStorage };