Graphical identification and authentication
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The graphical identification and authentication (GINA) library is a component of some Microsoft Windows operating systems that provides secure authentication and interactive logon services.
GINA is a replaceable dynamically linked library that is loaded early in the boot process in the context of Winlogon when the machine is started. It is responsible for handling the secure attention sequence, typically Control-Alt-Delete, and interacting with the user when this sequence is received. GINA is also responsible for starting initial processes for a user (such as the Windows Shell) when they first log on.
Overview
[[Image:Xp_windows_functionality into Winlogon, resulting in additional functionality that can be implemented by a replacement GINA. Windows 2000, for example, introduced support for displaying status messages (including verbose messages that can be turned on through Group Policy) about the current state to the user (e.g. "Applying computer settings..."), and starting applications in the user's context; this facilitates restarting Windows Explorer automatically if it crashes, as well as starting the Task Manager. Windows XP introduced support for Fast User Switching, Remote Desktop and a more interactive, simplified and user-friendly full-screen logon.
Recent Windows versions
In Windows Vista, GINA has been entirely replaced by Credential Providers, which allow for significantly increased flexibility in supporting multiple credential collection methods. To support the use of multiple GINA models, a complex chaining method used to be required and custom GINAs often did not work with fast user switching. GINA libraries do not work with Windows Vista and later Windows versions. One difference however, is that GINA could completely replace the Windows logon user interface, Credential Providers cannot.
See also
External links
- Winlogon and GINA, developer information on how the login components interact
- Customizing GINA Part 1, Developer tutorial for writing a custom GINA.
- Customizing GINA Part 2, Developer tutorial for writing a custom GINA.