Attestation registration is the first step in the attestation process. It allows your server to request and store a player’s public key from Ember Client, which can later be used for cryptographic verification through signing.
What is Attestation Registration?
Attestation registration prompts the Ember Client user to generate or provide their public key. This key is essential for:
- Verifying the authenticity of signed data
- Establishing trust between server and client
- Enabling secure cryptographic operations
The registration process involves sending a request packet to the client and listening for the response event containing the public key.
Implementation Steps
Send the registration request
Create and send an OutAttestationRegister packet to the player to initiate the registration process.import com.emberclient.serverapi.ECServerAPI;
import com.emberclient.serverapi.packet.impl.attestation.register.OutAttestationRegister;
import org.bukkit.entity.Player;
public void requestAttestation(Player player) {
// Check if the player is using Ember Client
if (!ECServerAPI.getInstance().isPlayerOnEmber(player.getUniqueId())) {
player.sendMessage("You must be using Ember Client to use this feature.");
return;
}
// Send the registration packet
ECServerAPI.getInstance().sendPacket(player, new OutAttestationRegister());
player.sendMessage("Attestation registration requested. Please check your client.");
}
Listen for the registration event
Create an event listener to handle the EmberAttestationRegisterEvent that fires when the client responds.import com.emberclient.serverapi.event.EmberAttestationRegisterEvent;
import com.emberclient.serverapi.packet.impl.attestation.register.AttestationRegisterResult;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
public class AttestationListener implements Listener {
@EventHandler
public void onAttestationRegister(EmberAttestationRegisterEvent event) {
Player player = event.getPlayer();
AttestationRegisterResult status = event.getStatus();
// Handle the registration result
switch (status) {
case SUCCESS:
handleSuccessfulRegistration(player, event.getPublicKey());
break;
case SIGNING_NOT_ALLOWED:
player.sendMessage("Signing is not allowed on your client.");
break;
case USER_CANCELLED:
player.sendMessage("You cancelled the attestation registration.");
break;
case UNKNOWN_ERROR:
player.sendMessage("An unknown error occurred during registration.");
break;
}
}
}
Store the public key
When registration is successful, store the player’s public key for future verification operations.import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
public class PublicKeyStorage {
private static final Map<UUID, PublicKey> publicKeys = new HashMap<>();
public static void storePublicKey(UUID playerId, X509EncodedKeySpec keySpec) {
try {
KeyFactory keyFactory = KeyFactory.getInstance("EC");
PublicKey publicKey = keyFactory.generatePublic(keySpec);
publicKeys.put(playerId, publicKey);
} catch (Exception e) {
e.printStackTrace();
}
}
public static PublicKey getPublicKey(UUID playerId) {
return publicKeys.get(playerId);
}
public static boolean hasPublicKey(UUID playerId) {
return publicKeys.containsKey(playerId);
}
}
private void handleSuccessfulRegistration(Player player, X509EncodedKeySpec publicKey) {
// Store the public key
PublicKeyStorage.storePublicKey(player.getUniqueId(), publicKey);
player.sendMessage("Attestation registration successful!");
}
Register the listener
Don’t forget to register your event listener in your plugin’s onEnable() method.@Override
public void onEnable() {
getServer().getPluginManager().registerEvents(new AttestationListener(), this);
}
Complete Example
Here’s a complete working implementation that ties everything together:
package com.example.plugin;
import com.emberclient.serverapi.ECServerAPI;
import com.emberclient.serverapi.event.EmberAttestationRegisterEvent;
import com.emberclient.serverapi.packet.impl.attestation.register.AttestationRegisterResult;
import com.emberclient.serverapi.packet.impl.attestation.register.OutAttestationRegister;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
public class AttestationManager implements Listener {
private final Map<UUID, PublicKey> publicKeys = new HashMap<>();
/**
* Request attestation registration from a player
*/
public void requestRegistration(Player player) {
// Verify player is using Ember Client
if (!ECServerAPI.getInstance().isPlayerOnEmber(player.getUniqueId())) {
player.sendMessage("You must be using Ember Client to register.");
return;
}
// Check if already registered
if (publicKeys.containsKey(player.getUniqueId())) {
player.sendMessage("You are already registered!");
return;
}
// Send registration packet
ECServerAPI.getInstance().sendPacket(player, new OutAttestationRegister());
player.sendMessage("Please approve the attestation request in your client.");
}
/**
* Handle attestation registration responses
*/
@EventHandler
public void onAttestationRegister(EmberAttestationRegisterEvent event) {
Player player = event.getPlayer();
AttestationRegisterResult status = event.getStatus();
switch (status) {
case SUCCESS:
// Convert and store the public key
try {
KeyFactory keyFactory = KeyFactory.getInstance("EC");
PublicKey publicKey = keyFactory.generatePublic(event.getPublicKey());
publicKeys.put(player.getUniqueId(), publicKey);
player.sendMessage("Attestation registration successful!");
player.sendMessage("Your public key has been stored.");
} catch (Exception e) {
player.sendMessage("Failed to process your public key.");
e.printStackTrace();
}
break;
case SIGNING_NOT_ALLOWED:
player.sendMessage("Signing is disabled in your Ember Client settings.");
break;
case USER_CANCELLED:
player.sendMessage("You cancelled the attestation request.");
break;
case UNKNOWN_ERROR:
player.sendMessage("An error occurred during registration. Please try again.");
break;
}
}
/**
* Check if a player has registered their public key
*/
public boolean isRegistered(UUID playerId) {
return publicKeys.containsKey(playerId);
}
/**
* Get a player's public key
*/
public PublicKey getPublicKey(UUID playerId) {
return publicKeys.get(playerId);
}
}
Registration Results
The AttestationRegisterResult enum contains the following possible outcomes:
SUCCESS - Registration completed successfully, public key is availableSIGNING_NOT_ALLOWED - The client has disabled signing in their settingsUSER_CANCELLED - The user declined the registration requestUNKNOWN_ERROR - An unexpected error occurred
Only when the status is SUCCESS will the getPublicKey() method return a non-null value.
Best Practices
Always verify that a player is using Ember Client with isPlayerOnEmber() before sending attestation packets.
Store public keys securely and consider persisting them to a database for long-term use. The in-memory storage shown in these examples will be lost on server restart.
Next Steps
Once you have successfully registered and stored a player’s public key, you can proceed to:
- Implement attestation signing to verify signed data
- Use the stored keys for cryptographic verification
- Build trust-based features requiring client authentication