Generating JWT Token for APNS Authentication

[Udit Agrawal]

Hi,

I am new to vertx, i am using vertx 3.9.3, i need to generate a JWT token for APNS authentication for iOS push notifications.

Here's what i did so far to generate the token but when i send the request to APNS it says "403 - InvalidProviderToken"....

I am creating the token like this - 

private String createJwt() {
Instant now = Instant.now();
JsonObject decoded = new JsonObject()
.put("alg", "ES256")
.put("kid", AUTHKEY_KID)
.put("iss", AUTHKEY_TEAMID)
.put("iat", now.getEpochSecond());
String jwt = oauth2JWTProvider.generateToken(decoded,
new JWTOptions().setAlgorithm("ES256"));
return jwt;
}

I am generating the oauth2JWTProvider like this - 

private JWTAuth createOauthProvider() {
PubSecKeyOptions pubSecKeyOptions = new PubSecKeyOptions()
.setAlgorithm("ES256").setSecretKey(*/private key from .p8 extracted as is removing unwanted part in base64*/);
return JWTAuth.create(vertx(), new JWTAuthOptions().addPubSecKey(pubSecKeyOptions));
}

Please provider any pointers necessary ? Thanks!!

[Paulo Lopes]

Hi,

I never uses APNs but from this manual: https://developer.apple.com/documentation/usernotifications/sending_push_notifications_using_command-line_tools

It looks like you're creating the token with the wrong format:

    Instant now = Instant.now();
    JsonObject decoded = new JsonObject()
      .put("alg", "ES256")

      .put("kid", "${AUTH_KEY_ID}")
      .put("iss", "${TEAM_ID}")
      .put("iat", now.getEpochSecond());

    token = authProvider.generateToken(
      decoded,
      new JWTOptions()
        .setAlgorithm("ES256"));

//    {
//      "typ": "JWT",
//      "alg": "ES256"
//    }.{
//      "alg": "ES256",
//        "kid": "${AUTH_KEY_ID}",
//        "iss": "${TEAM_ID}",
//        "iat": 1627582196
//    }.[Signature]

While from that manual I think you want:

   JsonObject payload = new JsonObject();

    String token = authProvider.generateToken(
      payload,
      new JWTOptions()
        .setIssuer("${TEAM_ID}")
        .setAlgorithm("ES256")
        .setHeader(new JsonObject().put("kid", "${AUTH_KEY_ID}")));

//    {
//      "kid": "${AUTH_KEY_ID}",
//      "typ": "JWT",
//      "alg": "ES256"
//    }.{
//      "iat": 1627580331,
//        "iss": "${TEAM_ID}"
//    }.[Signature]

Note that in order to change the default values or the contents of the header, you need to specify the fields in the jwtOptions, not on the claims.

"kid" is a missing property we should add a shortcut instead of needing the header to be provided manually (but that is an API improvement).

Let me know if this works for you!

Cheers,

Paulo