expand and document WrappedProfilePublicKey (#1618)

src/main/java/com/comphenix/protocol/wrappers/WrappedProfilePublicKey.java

@@ -1,13 +1,23 @@
 package com.comphenix.protocol.wrappers;
 
+import com.comphenix.protocol.injector.BukkitUnwrapper;
 import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.reflect.accessors.Accessors;
 import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
 import com.comphenix.protocol.reflect.accessors.FieldAccessor;
 import com.comphenix.protocol.utility.MinecraftReflection;
+import java.nio.charset.StandardCharsets;
 import java.security.PublicKey;
 import java.time.Instant;
+import java.util.Base64;
+import java.util.Base64.Encoder;
+import org.bukkit.entity.Player;
 
+/**
+ * A wrapper around the profile public key.
+ *
+ * @since 1.19
+ */
 public class WrappedProfilePublicKey extends AbstractWrapper {
 
 	private static final Class<?> HANDLE_TYPE = MinecraftReflection.getProfilePublicKeyClass();
@@ -16,65 +26,177 @@ public class WrappedProfilePublicKey extends AbstractWrapper {
 	private static final ConstructorAccessor CONSTRUCTOR = Accessors.getConstructorAccessor(HANDLE_TYPE, KEY_DATA_TYPE);
 	private static final FieldAccessor DATA_ACCESSOR = Accessors.getFieldAccessor(HANDLE_TYPE, KEY_DATA_TYPE, true);
 
+	// lazy initialized when needed
+	private static FieldAccessor PROFILE_KEY_ACCESSOR;
+
+	/**
+	 * Constructs a new profile public key wrapper directly from a nms ProfilePublicKey object.
+	 *
+	 * @param handle the handle to create the wrapper from.
+	 */
 	public WrappedProfilePublicKey(Object handle) {
 		super(HANDLE_TYPE);
 		this.setHandle(handle);
 	}
 
+	/**
+	 * Constructs a new profile public key wrapper holding the given key data.
+	 *
+	 * @param keyData the data of the key.
+	 */
 	public WrappedProfilePublicKey(WrappedProfileKeyData keyData) {
 		this(CONSTRUCTOR.invoke(keyData.getHandle()));
 	}
 
+	/**
+	 * Retrieves the profile public key from the given player instance.
+	 *
+	 * @param player the player to get the key of.
+	 * @return a wrapper around the public key of the given player.
+	 */
+	public static WrappedProfilePublicKey ofPlayer(Player player) {
+		FieldAccessor accessor = PROFILE_KEY_ACCESSOR;
+		if (accessor == null) {
+			accessor = Accessors.getFieldAccessor(MinecraftReflection.getEntityHumanClass(), HANDLE_TYPE, true);
+			PROFILE_KEY_ACCESSOR = accessor;
+		}
+
+		Object nmsPlayer = BukkitUnwrapper.getInstance().unwrapItem(player);
+		return new WrappedProfilePublicKey(accessor.get(nmsPlayer));
+	}
+
+	/**
+	 * Get a wrapper around the key data stored in this public key.
+	 *
+	 * @return the data of this key.
+	 */
 	public WrappedProfileKeyData getKeyData() {
 		return new WrappedProfileKeyData(DATA_ACCESSOR.get(this.getHandle()));
 	}
 
+	/**
+	 * Sets the data of this key. Note that changing the key data might lead to unexpected issues with the server, for
+	 * example chat message validation to fail.
+	 *
+	 * @param keyData the new data of this key.
+	 */
 	public void setKeyData(WrappedProfileKeyData keyData) {
 		DATA_ACCESSOR.set(this.getHandle(), keyData.getHandle());
 	}
 
+	/**
+	 * A wrapper around the data stored in a profile key.
+	 *
+	 * @since 1.19
+	 */
 	public static class WrappedProfileKeyData extends AbstractWrapper {
 
 		private static final ConstructorAccessor CONSTRUCTOR = Accessors.getConstructorAccessor(
 				KEY_DATA_TYPE,
 				Instant.class, PublicKey.class, byte[].class);
+		private static final Encoder MIME_ENCODER = Base64.getMimeEncoder(76, "\n".getBytes(StandardCharsets.UTF_8));
 
 		private final StructureModifier<Object> modifier;
 
+		/**
+		 * Constructs a new key data instance directly from the given nms KeyData object.
+		 *
+		 * @param handle the handle to create the wrapper from.
+		 */
 		public WrappedProfileKeyData(Object handle) {
 			super(KEY_DATA_TYPE);
 			this.setHandle(handle);
 			this.modifier = new StructureModifier<>(KEY_DATA_TYPE).withTarget(handle);
 		}
 
+		/**
+		 * Constructs a new data wrapper instance using the given parameters.
+		 *
+		 * @param expireTime the instant when the key data expires.
+		 * @param key        the public key used to verify incoming data.
+		 * @param signature  the signature of the public key.
+		 */
 		public WrappedProfileKeyData(Instant expireTime, PublicKey key, byte[] signature) {
 			this(CONSTRUCTOR.invoke(expireTime, key, signature));
 		}
 
+		/**
+		 * Get the time instant when this key data expires.
+		 *
+		 * @return the time instant when this key data expires.
+		 */
 		public Instant getExpireTime() {
 			return this.modifier.<Instant>withType(Instant.class).read(0);
 		}
 
+		/**
+		 * Sets the time when this key data expires.
+		 *
+		 * @param expireTime the new time when this key data expires.
+		 */
 		public void setExpireTime(Instant expireTime) {
 			this.modifier.<Instant>withType(Instant.class).write(0, expireTime);
 		}
 
+		/**
+		 * Checks if this key data is expired.
+		 *
+		 * @return true if this key data is expired, false otherwise.
+		 */
 		public boolean isExpired() {
 			return this.getExpireTime().isBefore(Instant.now());
 		}
 
+		/**
+		 * Get the signed payload of this key data. The signature of this data must verify against the payload data of
+		 * the key. If it does not, the key data is considered unsigned.
+		 * <p>
+		 * Note that this method takes the expiry time of the key into accountability, if this key is expired it will no
+		 * longer match the key data signature.
+		 *
+		 * @return the signed payload version of this profile key data.
+		 */
+		public String getSignedPayload() {
+			String rsaString = "-----BEGIN RSA PUBLIC KEY-----\n"
+					+ MIME_ENCODER.encodeToString(this.getKey().getEncoded())
+					+ "\n-----END RSA PUBLIC KEY-----\n";
+			return this.getExpireTime().toEpochMilli() + rsaString;
+		}
+
+		/**
+		 * Get the public key of this key data.
+		 *
+		 * @return the public key of this key data.
+		 */
 		public PublicKey getKey() {
 			return this.modifier.<PublicKey>withType(PublicKey.class).read(0);
 		}
 
+		/**
+		 * Sets the public key of this key data.
+		 *
+		 * @param key the new public key of this key data.
+		 */
 		public void setKey(PublicKey key) {
 			this.modifier.<PublicKey>withType(PublicKey.class).write(0, key);
 		}
 
+		/**
+		 * Get the signature of this key data.
+		 *
+		 * @return the key data of this signature.
+		 * @see #getSignedPayload()
+		 */
 		public byte[] getSignature() {
 			return this.modifier.<byte[]>withType(byte[].class).read(0);
 		}
 
+		/**
+		 * Sets the signature of this key data.
+		 *
+		 * @param signature the new signature of this key data.
+		 * @see #getSignedPayload()
+		 */
 		public void setSignature(byte[] signature) {
 			this.modifier.<byte[]>withType(byte[].class).write(0, signature);
 		}