Sol's AuthLogin System

Overview

Sol’s AuthLogin is a powerful and secure authentication system designed for Minecraft servers, now upgraded with a modern token-based auto-login system for improved security and player experience.

Note: Required to install into server/mods folder and is recommended to be installed on client-side as well for auto-login feature & stable authstate restrictions.

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🔐 Key Features

🆕 Secure Token-Based Auto-Login

Replaces outdated IP-based sessions with a secure token authentication system
Players receive a unique login token after /login or /register
Enables safe and seamless auto-login on future joins
Falls back to manual login if client mod is not installed

✔ Requires mod on both client & server for full functionality

🔑 Core Authentication System

/register <password> <confirm> — Create a new account
/login <password> — Authenticate returning players
/change_password <old> <new> <confirm> — Update credentials securely

🛡 Advanced Security Features

SHA-256 password hashing with per-user unique salt
Rate limiting to prevent brute-force login attempts
Temporary account lockout after failed attempts (configurable)
Multiple session prevention (one account = one player)
Optional session caching fallback for compatibility

🚫 Strict Pre-Authentication Protection

Until a player is authenticated, they are fully restricted:

No movement (frozen state)
No block breaking or placing
No inventory or container access
No item pickup
No combat interaction
No chat (except auth commands)
No command usage (except /login & /register)
Perspective switching is blocked

⏱ Smart Timeout System

Configurable login timeout with auto-kick
Grace period before teleporting after login
Action bar + title reminders at configurable intervals

📍 Spawn & Return System

Optional spawn teleport on join
Automatically returns players to their original position after login
Crash-safe position persistence
Supports world spawn or custom coordinates

🧩 Admin Commands (`/auth_admin`)

reload — Reload configuration
resetpassword <player> <newPassword> — Reset player password
unregister <player> — Remove player account
forcelogin <player> — Authenticate player manually
forcelogout <player> — De-authenticate player
info <player> — View auth status
list — List all registered players

⚙ Highly Configurable

Authentication timeout & session settings
Password rules (length, complexity, requirements)
Fully customizable messages
Flexible spawn/teleport behavior

🎯 Who Is This For?

✅ Ideal for Offline-Mode (Cracked) Servers

No Mojang authentication → anyone can use any username
Prevents account impersonation and griefing
Ensures only registered users can access their accounts
Essential for protecting player progress and data

⚠ On Online-Mode Servers

Mojang already verifies player identity and UUID
No risk of impersonation
Using this mod may cause double authentication (Mojang + mod)

👉 Still usable, but generally redundant unless extra security layers are needed

🚀 Why Choose Sol’s AuthLogin?

Strong protection against common exploits
Smooth player experience with auto-login
Built for stability, configurability, and real server environments

Author: Solmochi

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