java - 在 Java 中生成 VAPID key 并将其传递给 JavaScript PushManager

Question

我正在尝试在我的应用程序中通过网络推送协议(protocol)使用网络推送通知。为了将 Push API 与 VAPID 结合使用，我需要一个 applicationServerKey。

PushManager subscribe 方法采用 VAPID key (仅公钥)作为参数，并提供订阅端点和推送消息的 key 。

为了生成 VAPID key ，到目前为止，我一直在使用 node.js(google web-push 包)和 openssl 。但在我的用例中，VAPID key 应该在 Java 中生成并传递给 JavaScript 以从浏览器订阅。

我正在尝试使用下面的 Java 代码来生成 VAPID key 。我能够成功创建 key ，但是当我传递生成的公钥(base64 编码字符串)时，subscribe 方法返回一个错误:

Unable to register service worker. DOMException: Failed to execute 'subscribe' on 'PushManager': The provided applicationServerKey is not valid..

请帮我解决这个问题。下面是我的Java代码:

ECNamedCurveParameterSpec parameterSpec = 
ECNamedCurveTable.getParameterSpec("prime256v1");
KeyPairGenerator keyPairGenerator = 
KeyPairGenerator.getInstance("ECDH", "BC");
keyPairGenerator.initialize(parameterSpec);
KeyPair serverKey = keyPairGenerator.generateKeyPair();

PrivateKey priv = serverKey.getPrivate();
PublicKey pub = serverKey.getPublic();`
System.out.println(Base64.toBase64String(pub.getEncoded()));

Answer 1

请参阅以下链接以获取 MartijnDwars 的回答。 https://github.com/web-push-libs/webpush-java/issues/30

you can use Utils.savePublicKey to convert your Java-generated PublicKey to a byte[]. This byte[] is then passed to the PushManager.subscribe method.

It may be more convenient to base64 encode the byte[] in Java and base64 decode the string in JavaScript. For example, after generating the keypair in Java:

KeyPair keyPair = generateKeyPair();
byte[] publicKey = Utils.savePublicKey((ECPublicKey) keyPair.getPublic());
String publicKeyBase64 = BaseEncoding.base64Url().encode(publicKey);
System.out.println("PublicKey = " + publicKeyBase64);
// PublicKey = BPf36QAqZNNvvnl9kkpTDerXUOt6Nm6P4x9GEvmFVFKgVyCVWy24KUTs6wLQtbV2Ug81utbNnx86_vZzXDyrl88=

Then in JavaScript:

function subscribe() {
    const publicKey = base64UrlToUint8Array('BPf36QAqZNNvvnl9kkpTDerXUOt6Nm6P4x9GEvmFVFKgVyCVWy24KUTs6wLQtbV2Ug81utbNnx86_vZzXDyrl88=');

    navigator.serviceWorker.ready.then(function (serviceWorkerRegistration) {
        serviceWorkerRegistration.pushManager.subscribe({
            userVisibleOnly: true,
            applicationServerKey: publicKey
        })
        .then(function (subscription) {
            return sendSubscriptionToServer(subscription);
        })
        .catch(function (e) {
            if (Notification.permission === 'denied') {
                console.warn('Permission for Notifications was denied');
            } else {
                console.error('Unable to subscribe to push.', e);
            }
        });
    });
}

function base64UrlToUint8Array(base64UrlData) {
    const padding = '='.repeat((4 - base64UrlData.length % 4) % 4);
    const base64 = (base64UrlData + padding)
        .replace(/\-/g, '+')
        .replace(/_/g, '/');

    const rawData = atob(base64);
    const buffer = new Uint8Array(rawData.length);

    for (let i = 0; i < rawData.length; ++i) {
        buffer[i] = rawData.charCodeAt(i);
    }

    return buffer;
}