Fix UDP discovery to work with the new fingerprint size

app/src/main/java/io/xeres/app/net/bdisc/ProtocolVersion.java

@@ -22,5 +22,6 @@
 enum ProtocolVersion
 {
 	VERSION_0,
-	VERSION_1
+	VERSION_1,
+	VERSION_2
 }

app/src/main/java/io/xeres/app/net/bdisc/UdpDiscoveryProtocol.java

@@ -30,8 +30,7 @@
 import java.net.InetSocketAddress;
 import java.nio.ByteBuffer;
 
-import static io.xeres.app.net.bdisc.ProtocolVersion.VERSION_0;
-import static io.xeres.app.net.bdisc.ProtocolVersion.VERSION_1;
+import static io.xeres.app.net.bdisc.ProtocolVersion.*;
 
 public final class UdpDiscoveryProtocol
 {
@@ -66,7 +65,7 @@ public static UdpDiscoveryPeer parsePacket(ByteBuffer buffer, InetSocketAddress
 			case MAGIC_HEADER_VERSIONED ->
 			{
 				var versionNum = buffer.get();
-				if (versionNum > VERSION_1.ordinal())
+				if (versionNum > VERSION_2.ordinal())
 				{
 					log.warn("Unsupported protocol version: {}", versionNum);
 					return null;
@@ -116,7 +115,20 @@ public static UdpDiscoveryPeer parsePacket(ByteBuffer buffer, InetSocketAddress
 		}
 
 		var buf = Unpooled.wrappedBuffer(buffer);
-		peer.setFingerprint((ProfileFingerprint) Serializer.deserializeIdentifier(buf, ProfileFingerprint.class));
+		if (protocolVersion != VERSION_2)
+		{
+			peer.setFingerprint((ProfileFingerprint) Serializer.deserializeIdentifierWithSize(buf, ProfileFingerprint.class, ProfileFingerprint.V4_LENGTH));
+		}
+		else
+		{
+			var fingerPrintSize = buffer.get();
+			switch (fingerPrintSize)
+			{
+				case 20 -> peer.setFingerprint((ProfileFingerprint) Serializer.deserializeIdentifierWithSize(buf, ProfileFingerprint.class, ProfileFingerprint.V4_LENGTH));
+				case 32 -> peer.setFingerprint((ProfileFingerprint) Serializer.deserializeIdentifierWithSize(buf, ProfileFingerprint.class, ProfileFingerprint.LENGTH));
+				default -> throw new IllegalArgumentException("Unknown fingerprint size:" + fingerPrintSize);
+			}
+		}
 		peer.setLocationId((LocationId) Serializer.deserializeIdentifier(buf, LocationId.class));
 		peer.setLocalPort(Serializer.deserializeShort(buf));
 		peer.setProfileName(Serializer.deserializeString(buf));
@@ -129,7 +141,18 @@ public static ByteBuffer createPacket(int maxSize, Status status, int appId, int
 		var buffer = ByteBuffer.allocate(maxSize);
 
 		buffer.putInt(MAGIC_HEADER_VERSIONED);
-		buffer.put((byte) VERSION_1.ordinal()); // protocol version
+		if (fingerprint.getLength() == 32)
+		{
+			buffer.put((byte) VERSION_2.ordinal()); // protocol version
+		}
+		else if (fingerprint.getLength() == 20)
+		{
+			buffer.put((byte) VERSION_1.ordinal()); // protocol version
+		}
+		else
+		{
+			throw new IllegalArgumentException("Unknown fingerprint size:" + fingerprint.getLength());
+		}
 		buffer.put((byte) 0);
 		buffer.put((byte) 0);
 		buffer.put((byte) 0);

app/src/main/java/io/xeres/app/xrs/serialization/IdentifierSerializer.java

@@ -79,6 +79,24 @@ static Identifier deserialize(ByteBuf buf, Class<?> identifierClass)
 		}
 	}
 
+	static Identifier deserializeWithSize(ByteBuf buf, Class<?> identifierClass, int size)
+	{
+		try
+		{
+			//noinspection PrimitiveArrayArgumentToVarargsMethod
+			var identifier = (Identifier) identifierClass.getDeclaredConstructor(byte[].class).newInstance(ByteArraySerializer.deserialize(buf, size));
+			if (Arrays.equals(identifier.getNullIdentifier(), identifier.getBytes()))
+			{
+				return null;
+			}
+			return identifier;
+		}
+		catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e)
+		{
+			throw new IllegalStateException(e.getMessage());
+		}
+	}
+
 	static int getIdentifierLength(Class<?> identifierClass)
 	{
 		try

app/src/main/java/io/xeres/app/xrs/serialization/Serializer.java

@@ -22,6 +22,7 @@
 import io.netty.buffer.ByteBuf;
 import io.xeres.app.database.model.gxs.GxsMetaAndData;
 import io.xeres.common.id.Identifier;
+import io.xeres.common.id.ProfileFingerprint;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -265,6 +266,21 @@ public static Identifier deserializeIdentifier(ByteBuf buf, Class<?> identifierC
 		return IdentifierSerializer.deserialize(buf, identifierClass);
 	}
 
+	/**
+	 * Deserializes an identifier while specifying its size.
+	 * <p>
+	 * This is required for some identifier that can have a varying size, like {@link ProfileFingerprint}.
+	 *
+	 * @param buf             the buffer
+	 * @param identifierClass the class of the identifier
+	 * @param size            the size to deserialize
+	 * @return the identifier
+	 */
+	public static Identifier deserializeIdentifierWithSize(ByteBuf buf, Class<?> identifierClass, int size)
+	{
+		return IdentifierSerializer.deserializeWithSize(buf, identifierClass, size);
+	}
+
 	/**
 	 * Serializes a byte array.
 	 *