/// <summary>
/// Gets the active session user token.
/// </summary>
/// <param name="userToken">The user token.</param>
/// <returns></returns>
/// <exception cref="Win32Exception"></exception>
public static TokenHandle GetActiveSessionUserToken()
{
//!!! Parts are from Copyright (c) 2014 Justin Murray - MIT-License, thanks to him !!!
// https://github.com/murrayju/CreateProcessAsUser, 18.08.2019
var primTokenHandle = new TokenHandle();
uint activeSessionId = Wtsapi32.InvalidSessionId;
IntPtr sessionInfos = IntPtr.Zero;
var sessionCount = 0;
try
{
//Get a handle to the user access token for the current active session.
if (Wtsapi32.WTSEnumerateSessions(Wtsapi32.WtsCurrentServerHandle, 0, 1, ref sessionInfos, ref sessionCount))
{
int arrayElementSize = Marshal.SizeOf(typeof(Wtsapi32.WtsSessionInfo));
IntPtr current = sessionInfos;
for (var i = 0; i < sessionCount; i++)
{
var sessionInfo = (Wtsapi32.WtsSessionInfo)Marshal.PtrToStructure(current, typeof(Wtsapi32.WtsSessionInfo));
current += arrayElementSize;
if (sessionInfo.State == Wtsapi32.WtsConnectstateClass.WTSActive)
{
activeSessionId = (uint)sessionInfo.SessionID;
}
}
}
}
finally
{
if (sessionInfos != IntPtr.Zero)
{
Wtsapi32.WTSFreeMemory(sessionInfos);
}
}
//If enumerating not working use the fall back method
if (activeSessionId == Wtsapi32.InvalidSessionId)
{
activeSessionId = Kernel32.WTSGetActiveConsoleSessionId();
if (activeSessionId == Wtsapi32.InvalidSessionId)
{
throw new Exception("No valid session found.");
}
}
var impersonationToken = new TokenHandle();
try
{
//Get token
if (!Wtsapi32.WTSQueryUserToken(activeSessionId, out impersonationToken))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
//Convert the impersonation token to a primary token
if (!Advapi32.DuplicateTokenEx(impersonationToken, 0, IntPtr.Zero, (int)Advapi32.SecurityImpersonationLevel.SecurityImpersonation, (int)Advapi32.TokenType.TokenPrimary, ref primTokenHandle))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
finally
{
impersonationToken.Close();
}
return(primTokenHandle);
}
/// <summary>
/// Gets the session token by the username.
/// </summary>
/// <param name="username">The username.</param>
/// <returns></returns>
/// <exception cref="Exception">No valid session found.</exception>
/// <exception cref="Win32Exception">
/// </exception>
public static TokenHandle GetSessionTokenByUsername(string username)
{
//!!! Parts are from Copyright (c) 2014 Justin Murray - MIT-License, thanks to him !!!
// https://github.com/murrayju/CreateProcessAsUser, 18.08.2019
var primTokenHandle = new TokenHandle();
uint activeSessionId = Wtsapi32.InvalidSessionId;
IntPtr sessionInfos = IntPtr.Zero;
IntPtr usernamePtr = IntPtr.Zero;
IntPtr domainPtr = IntPtr.Zero;
var sessionCount = 0;
try
{
//Get a handle to the user access token for the current active session.
if (Wtsapi32.WTSEnumerateSessions(Wtsapi32.WtsCurrentServerHandle, 0, 1, ref sessionInfos, ref sessionCount))
{
int arrayElementSize = Marshal.SizeOf(typeof(Wtsapi32.WtsSessionInfo));
IntPtr current = sessionInfos;
for (var i = 0; i < sessionCount; i++)
{
var sessionInfo = (Wtsapi32.WtsSessionInfo)Marshal.PtrToStructure(current, typeof(Wtsapi32.WtsSessionInfo));
current += arrayElementSize;
//If the session is not active, go to the next
if (sessionInfo.State != Wtsapi32.WtsConnectstateClass.WTSActive)
{
continue;
}
//Get the username
if (!Wtsapi32.WTSQuerySessionInformation(Wtsapi32.WtsCurrentServerHandle, sessionInfo.SessionID, Wtsapi32.WtsInfoClass.WtsUserName, out usernamePtr, out uint bytesReturnedUsername))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
//continue when no bytes returned
if (bytesReturnedUsername <= 0)
{
continue;
}
string sessionUsername = Marshal.PtrToStringUni(usernamePtr);
//Get the domain name
if (!Wtsapi32.WTSQuerySessionInformation(Wtsapi32.WtsCurrentServerHandle, sessionInfo.SessionID, Wtsapi32.WtsInfoClass.WtsDomainName, out domainPtr, out uint bytesReturnedDomainName))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
//continue when no bytes returned
if (bytesReturnedDomainName <= 0)
{
continue;
}
string sessionDomainName = Marshal.PtrToStringUni(domainPtr);
//If the username is not the same, go to the next
string sessionFullUsername = sessionDomainName.ConvertNullTerminatedStringToString() + "\\" + sessionUsername.ConvertNullTerminatedStringToString();
if (sessionUsername == null || !string.Equals(username.Trim(), sessionFullUsername, StringComparison.CurrentCultureIgnoreCase))
{
continue;
}
//If the session is found break the for
activeSessionId = (uint)sessionInfo.SessionID;
break;
}
}
else
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
finally
{
if (usernamePtr != IntPtr.Zero)
{
Wtsapi32.WTSFreeMemory(usernamePtr);
}
if (domainPtr != IntPtr.Zero)
{
Wtsapi32.WTSFreeMemory(domainPtr);
}
if (sessionInfos != IntPtr.Zero)
{
Wtsapi32.WTSFreeMemory(sessionInfos);
}
}
//If enumerating not working throw an exception
if (activeSessionId == Wtsapi32.InvalidSessionId)
{
throw new Exception("No valid session found.");
}
var impersonationToken = new TokenHandle();
try
{
//Get token
if (!Wtsapi32.WTSQueryUserToken(activeSessionId, out impersonationToken))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
//Convert the impersonation token to a primary token
if (!Advapi32.DuplicateTokenEx(impersonationToken, 0, IntPtr.Zero, (int)Advapi32.SecurityImpersonationLevel.SecurityImpersonation, (int)Advapi32.TokenType.TokenPrimary, ref primTokenHandle))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
finally
{
impersonationToken.Close();
}
return(primTokenHandle);
}
