Player Identity

The Interposer can override the username and computer name returned by the Windows API so that games see custom values instead of the real Windows account and machine names. This is useful when multiple users share the same Windows installation, or when a game uses these values for player identification.

Username

How It Works

When GetUserNameW or GetUserNameA is called by the game, the hook returns the configured username instead of delegating to the operating system.

Configuring the Username

Set Username under the Player section of .interposer/Config.yml:

Player:
  Username: 'Player1'

Leave Username empty (or omit the key entirely) to pass calls through to the real Windows API unchanged.

Overriding the Username at Launch

To set the username without editing .interposer/Config.yml, pass --username to the injector:

Injector.exe --username Player1 --launch "C:\Games\game.exe"

The name is passed to the DLL via a named memory-mapped file (Local\InterposerUsername_<pid>) and overrides any Username value in the config.

Computer Name

How It Works

When GetComputerNameW or GetComputerNameA is called by the game, the hook returns the configured computer name.

Configuring the Computer Name

Set ComputerName under the Player section of .interposer/Config.yml:

Player:
  ComputerName: 'GAMEPC'

Leave ComputerName empty (or omit the key) to pass calls through to the real Windows API unchanged.

Overriding the Computer Name at Launch

Injector.exe --computername GAMEPC --launch "C:\Games\game.exe"

The name is passed via Local\InterposerComputerName_<pid> and overrides the config value.

Hooked Functions

Function	DLL	Notes
GetUserNameW	advapi32	Returns the configured username as a wide string. On buffer-too-small: ERROR_INSUFFICIENT_BUFFER.
GetUserNameA	advapi32	Returns the configured username in the system ANSI code page. On buffer-too-small: ERROR_INSUFFICIENT_BUFFER.
GetComputerNameW	kernel32	Returns the configured computer name as a wide string. On buffer-too-small: ERROR_BUFFER_OVERFLOW.
GetComputerNameA	kernel32	Returns the configured computer name in the system ANSI code page. On buffer-too-small: ERROR_BUFFER_OVERFLOW.

All four functions honour their respective Windows API buffer contracts. Passing NULL as the buffer performs a size query.

Each pair is only hooked when its corresponding config value (or injector argument) is non-empty — if both are unset, no hooks are installed and all calls pass through to the real API.