Security

Security

A3SQL provides two layers of security: parameterized queries for SQL injection prevention and TCP login authentication for network access.

Parameterized Queries

The primary SQL injection prevention mechanism. Pass user input as separate callExtension arguments rather than interpolating into SQL:

// ❌ Unsafe — string interpolation allows injection
_uid = "foo' OR '1'='1";
_result = [format ["DELETE FROM players WHERE uid = '%1'", _uid]] call a3sql_fnc_execute;

// ✅ Safe — $1 placeholder gets escaped by the extension
_uid = "foo' OR '1'='1";
_result = ["a3sql", "DELETE FROM players WHERE uid = $1", [_uid]] call a3sql_fnc_execute;

Escaping rules (applied by the Rust extension before SQL parsing):

Input type	Behavior
Empty string	Rendered as '' (empty string literal)
NULL / null	Rendered as bare NULL
Integer / float	Passed through as-is
true / false	Passed through as-is
Already quoted	Passed through as-is ('foo' stays 'foo')
Everything else	Wrapped in single quotes with ' doubled to ''

The extension processes placeholders ($1, $2, etc.) before SQL parsing — the substituted SQL is never exposed to the caller.

TCP Login Authentication

When the TCP listener is enabled, external connections can be protected with username/password authentication.

Setup

Set credentials via CBA Settings or in SQF before starting the listener:

// In fn_settings.sqf (PreInit) or from a mission
["a3sql_listener_user", "admin"] call CBA_fnc_setVar;
["a3sql_listener_password", "secret123"] call CBA_fnc_setVar;
["a3sql_listener_enabled", true] call CBA_fnc_setVar;

When credentials are set, the listener requires every TCP client to authenticate first.

Login Protocol

> LOGIN admin secret123
< [0,"OK","Authenticated"]

If authentication fails:

> LOGIN bad wrong
< [-1,"ERR_AUTH","Invalid credentials"]

Clients that fail authentication are disconnected immediately. Clients that don't send LOGIN at all:

> SELECT * FROM players
< [-1,"ERR_AUTH","LOGIN <user> <pass> required"]

Anonymous Access

Leave both a3sql_listener_user and a3sql_listener_password empty (default) for anonymous access — no LOGIN command needed.

Remote Server Mode

When using the extension's connect command to forward queries to a remote a3sql-server, the TCP connection itself is unauthenticated (the remote server's local credentials check applies if configured). Future versions may add credential forwarding.

Response Format

All security errors follow the standard response format:

[-1,"ERR_AUTH","description of error"]