Tag Archives: PKINIT

Determine if a Smart Card Was Used for Logon

This method can only determine if a logon used Public Key Cryptography for Initial Authentication (PKINIT); successive locks / unlocks will continue to report the information from the initial logon.

According to this article: http://social.technet.microsoft.com/wiki/contents/articles/11844.find-out-if-a-smart-card-was-used-for-logon.aspx, a special security group is injected into the user’s access token when a smart card is used. Comparing the current user token group members between a password and smart card authenticated session revealed the group “NT Authority\This Organization Certificate” (S-1-5-65-1). (PowerShell for this below)

A search for S-1-5-65-1 returned this article: https://msdn.microsoft.com/en-us/library/cc980032.aspx, with the following information:



A SID that indicates that the client’s Kerberos service ticket’s PAC contained a NTLM_SUPPLEMENTAL_CREDENTIAL structure (as specified in [MS-PAC] section 2.6.4). If the OTHER_ORGANIZATION SID is present, then this SID MUST NOT be present. <25>

Following the link to section 2.6.4 leads to the description: “The PAC buffer type is included only when PKINIT [MS-PKCA] is used to authenticate the user”

So, by what I can find and test, the presence of “NT Authority\This Organization Certificate” (S-1-5-65-1) in the user’s access token groups positively indicates whether the initial authentication used PKINIT, e.g., smart card.

This can be tested with the following PowerShell code:

$objGroup = New-Object System.Security.Principal.SecurityIdentifier("S-1-5-65-1")

WLS now uses a similar method with SessionMonitor. Any time a session changes, the AuthenticationType, CredentialProvider, and PKINIT will now be reported.

2015-11-18T07:16:54-06:00 [host] WLS_SessionMonitor: LogType=”WLS”, ApplicationName=””, AuthenticationType=”Kerberos”, BuildNumber=”0″, ClientAddress=””, ClientDirectory=””, ClientName=””, CredentialProvider=”Smartcard Credential Provider”, EncryptionLevel=”High”, HardwareId=”0″, InitialProgram=””, Message=”SessionUnlock”, PKINIT=”True”, ProductId=”0″, Protocol=”Console”, Resolution=”640×480″, SessionId=”10″, SessionName=”Console”, SourceAddress=””, SourceName=””, User=”[domain]\[user]”, WLSKey=”677″, WorkDirectory=””

For more information on WLS, click “WLS Information” at the top, or here: WLS Information

If you’d like additional information about WLS, send me a note via the contact form. WLS is currently available to US entities, but does require a signed license agreement.