MSV1_0 Authentication Package

Microsoft provides the MSV1_0 authentication package for local machine logons that do not require custom authentication. The Local Security Authority (LSA) calls the MSV1_0 authentication package to process logon data collected by the GINA for the Winlogon logon process. The MSV1_0 package checks the local security accounts manager (SAM) database to determine whether the logon data belongs to a valid security principal and then returns the result of the logon attempt to the LSA.

MSV1_0 also supports ___domain logons. MSV1_0 processes ___domain logons using pass-through authentication, as illustrated in the following diagram.

In pass-through authentication, the local instance of MSV1_0 uses the Netlogon service to call the instance of MSV1_0 running on the ___domain controller. The ___domain controller's instance of MSV1_0 then checks the SAM database of the ___domain controller and returns the logon result to the instance of MSV1_0 on the local machine. The local version of MSV1_0 forwards the logon result to the instance of the LSA on the local machine.

If the ___domain controller is not available, and the LSA contains cached credentials for the user, the local instance of MSV1_0 can authenticate the user using the cached logon data.

The MSV1_0 authentication package also supports subauthentication packages. A subauthentication package is a DLL that can replace part of the authentication and validation criteria used by the MSV1_0 authentication package.

The MSV1_0 authentication package defines a primary credentials key/string value pair. The primary credentials string holds the credentials derived from the data provided at logon time. It includes the user name and both case-sensitive and case-insensitive forms of the user's password.