SAuth

SAuth

SAuth is a lightweight and secure authentication mod for Minecraft Fabric servers.

It provides account registration and login for offline players while automatically recognizing authenticated Minecraft accounts.

SAuth works on dedicated servers, LAN worlds, singleplayer and modpacks, while keeping normal players free from mandatory client-side installation.

Authentication data, settings and registered accounts are stored separately for each Minecraft world.

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✨ Features

Authentication

Offline players can register using:

/register <password> <password>

Returning players can log in using:

/login <password>

Until authentication is completed, SAuth restricts normal gameplay actions.

This includes protection against:

• Movement and gameplay interaction
• Breaking and placing blocks
• Using items
• Attacking entities
• Inventory interaction
• Dropping items
• Other actions before authentication

After a successful login or registration, normal gameplay is restored.

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Official Account Detection

SAuth supports both official Minecraft accounts and offline accounts.

Official accounts authenticated by Minecraft are automatically recognized and do not require a local SAuth password.

Offline accounts use the normal registration and login system.

This allows SAuth to work in environments such as:

• Dedicated servers
• Offline-mode servers
• LAN worlds
• Modpacks
• Development and testing environments

Protected official accounts cannot simply be replaced by an offline player using the same registered identity.

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Per-World Accounts

SAuth stores authentication data separately for each Minecraft world.

For example:

World_A/sauth/
World_B/sauth/

Accounts registered in one world are not automatically registered in another.

This is useful for:

• LAN worlds
• Multiple server saves
• Testing worlds
• Modpack development
• Separate survival and roleplay worlds

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Authentication Spawn

Administrators can configure a dedicated authentication spawn.

Players can be temporarily moved to this location while waiting to register or log in.

Their previous position is preserved and restored after successful authentication.

The authentication spawn can be configured from the SAuth administration panel.

Selecting a new spawn does not immediately overwrite the previous location.

The administrator must press Save before the new position is applied.

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Dark Login

SAuth includes an optional Dark Login mode.

While a player is waiting to authenticate, a darker visual effect can be applied to separate the authentication process from normal gameplay.

This option can be enabled or disabled by administrators.

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🔐 Password Security

Passwords are never stored as plain text.

SAuth uses:

• PBKDF2-HMAC-SHA256
• Random password salts
• 600,000 hashing iterations
• 256-bit derived password hashes
• Constant-time hash comparison
• Login attempt rate limiting
• Temporary protection after repeated failed attempts
• Configurable minimum password length
• Protection against using the player's username as the password

Changing a password securely replaces the stored password hash.

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👤 Account Management

Players can change their own password using:

/sauth password <current_password> <new_password>

Players can also request deletion of their own account using:

/sauth account delete

Account deletion requires password confirmation.

Pending deletion requests can also be cancelled.

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🛠️ Administration

Administrators can open the SAuth administration panel using:

/adminauth

The panel provides access to authentication settings and registered accounts.

Administrators can manage:

• Authentication spawn
• Authentication spawn on every login
• Dark Login
• Login timeout
• Registration timeout
• Password requirements
• Registered accounts
• Account password reset
• Account removal
• Message highlight colors

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Smart Admin Interface

SAuth automatically chooses the best administration interface available.

With SAuth installed client-side

/adminauth

opens the custom SAuth administration interface.

Without SAuth installed client-side

SAuth automatically opens a vanilla Minecraft inventory menu.

This allows administrators to manage SAuth even without installing the mod on their client.

The vanilla interface can also be forced manually using:

/adminauth vanilla

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Configurable Highlight Colors

Administrators can customize the colors used for highlighted parts of SAuth messages.

The actual translated messages cannot be edited from the panel.

Only important highlights can be customized, including:

• Commands
• Arguments
• Important values
• Authentication instructions

Minecraft & formatting codes are supported.

Examples:

&b
&e
&6
&b&l

Normal message text remains white.

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Clean Chat Messages

Authentication messages are visually separated from normal chat.

Important prompts include spacing above and below the message to avoid mixing authentication instructions with player conversations.

Commands and arguments are highlighted automatically.

Example:

You need to log in. Use /login <password>.

The normal text stays white while commands and arguments use the configured highlight colors.

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📦 Recommended Versions

Requirement	Recommended
Minecraft	1.20.1 or 1.21.1
Mod Loader	Fabric
Fabric Loader	0.18.4+
Fabric API	Required
Java — 1.20.1	Java 17
Java — 1.21.1	Java 21

Recommended Fabric Loader: 0.18.4 or newer.

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🖥️ Client-Side or Server-Side?

SAuth is designed primarily as a Server-Side mod.

Recommended

Server: SAuth installed
Client: Not required

Normal players do not need SAuth installed.

Installing SAuth client-side provides the custom administration interface.

Without the client mod, administrators automatically receive the vanilla administration menu.

Setup	Supported
Server only	✅ Recommended
Client + Server	✅ Supported
LAN worlds	✅ Supported
Singleplayer	✅ Supported
Required for players	❌ No

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⌨️ Commands

/register

/register <password> <password>

Registers a new offline SAuth account.

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/login

/login <password>

Authenticates an existing offline account.

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/sauth password

/sauth password <current_password> <new_password>

Changes your account password.

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/sauth account delete

/sauth account delete

Starts the account deletion process.

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/adminauth

/adminauth

Opens the SAuth administration panel.

The custom interface is used when SAuth is installed client-side.

Otherwise, the vanilla administration interface is opened automatically.

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/adminauth vanilla

/adminauth vanilla

Forces the vanilla administration menu.

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/adminauth reload

/adminauth reload

Reloads the SAuth configuration for the current world.

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🌐 Languages

SAuth includes:

• English
• Portuguese (Brazil)
• Spanish
• Japanese
• Simplified Chinese
• Hindi
• Arabic

Player-facing messages and menus automatically use the language reported by the Minecraft client.