Replace the XOR obfuscation cipher with AES-128-CTR using the Windows
BCrypt API. Key material grows from 16 to 32 bytes (16 AES key + 16 IV).
All callers auto-adjust via StreamCipher::KEY_SIZE. No handshake or
protocol changes needed beyond the larger MC|CKey payload.
Comprehensive security system to protect against packet-sniffing attacks,
XUID harvesting, privilege escalation, bot flooding, and XUID impersonation.
- Stream cipher: per-session XOR cipher with 4-message handshake via
CustomPayloadPacket (MC|CKey, MC|CAck, MC|COn). Negotiated per-connection,
backwards compatible (old clients/servers fall back to plaintext).
- Security gate: buffers all game data until cipher handshake completes,
preventing unsecured clients from receiving any XUIDs or game state.
- Cipher handshake enforcer: kicks clients that don't complete the handshake
within 5 seconds (configurable via require-secure-client).
- Identity tokens: persistent per-XUID tokens in identity-tokens.json,
issued over the encrypted channel, verified on reconnect. Prevents XUID
replay attacks. Client stores server-specific tokens.
- PROXY protocol v1: parses real client IPs from playit.gg tunnel headers
so rate limiting, IP bans, and XUID spoof detection work per-player.
- Rate limiting: per-IP sliding window (default 5 connections/30s) with
pending connection cap (default 10).
- Privilege hardening: OP requires ops.json, live checks on every command
and privilege packet. Host-only server settings changes.
- XUID stripping: PreLoginPacket response sends INVALID_XUID placeholders.
- Packet validation: readUtf global string cap, reduced max packet size,
stream desync protection on oversized strings.
- OpManager: persistent ops.json with XUID-based OP list.
- Whitelist improvements: whitelist add accepts player names with ambiguity
detection, XUID cache from login attempts.
- revoketoken command: revoke identity tokens for players who lost theirs.
- server.log: persistent log file written alongside console output with
flush-per-write to survive crashes.
- CLI security logging: consolidated per-join security summary with cipher
status, token status, XUID, and real IP. Security warnings for kicks,
spoofing, and unauthorized commands.
Dragon melee damage: reassign sub-entity IDs to be sequential from
the parent entity ID in ServerLevel::entityAdded(), so the client's
offset-based ID calculation matches the server. Previously the server's
smallId pool allocated non-sequential IDs, causing melee attacks to
target entity IDs the server didn't recognize.
End portal transition: ensure the player entity is always added to the
new level when transitioning from The End, not just for non-End
dimensions. The addEntity call was previously gated behind a
lastDimension != 1 check that also excluded it from End exits.
End Poem crash: bounds-check the WIN_GAME event's player index before
accessing localplayers[], with a fallback to prevent null dereference
when the server sends an out-of-range index.
triggerEvent() set ignoreUpdate to true at the start but three early
return paths skipped the reset at the end. Once any of these paths was
hit, the TLS flag stayed true permanently, blocking all piston neighbor
updates for the rest of the server session.
triggerEvent() set ignoreUpdate to true at the start but three early
return paths (lines 221, 225, 250) skipped the reset at the end. Once
any of these paths was hit (common with fast redstone clocks where the
signal state changes between event queuing and processing), the TLS
flag stayed true permanently, blocking all piston neighbor updates for
the rest of the server session.
The dedicated server previously picked a completely random seed with no
biome diversity checks (the client validates but the server skipped it).
On top of that, the client's findSeed() was hardcoded to only check a
54-chunk (Classic) area, so Large worlds had no diversity guarantee
beyond the center.
New server worlds now use findSeed() scaled to the full target world
size. Added override-seed in server.properties to fix existing worlds
without deleting them.
Lord_Cambion