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.
