/// <summary>
/// Wraps the NetWkstaUserEnum API call in a timeout
/// </summary>
/// <param name="computer"></param>
/// <returns></returns>
private static async Task <List <Session> > GetLoggedOnUsersAPI(Computer computer)
{
var resumeHandle = 0;
var workstationInfoType = typeof(WKSTA_USER_INFO_1);
var ptrInfo = IntPtr.Zero;
var entriesRead = 0;
var sessionList = new List <Session>();
try
{
var task = Task.Run(() => NetWkstaUserEnum(computer.APIName, 1, out ptrInfo,
-1, out entriesRead, out _, ref resumeHandle));
if (await Task.WhenAny(task, Task.Delay(10000)) != task)
{
if (Options.Instance.DumpComputerStatus)
{
OutputTasks.AddComputerStatus(new ComputerStatus
{
ComputerName = computer.DisplayName,
Status = "Timeout",
Task = "NetWkstaUserEnum"
});
}
return(sessionList);
}
var taskResult = task.Result;
//Check the result of the task. 234 and 0 are both acceptable.
if (taskResult != 0 && taskResult != 234)
{
if (Options.Instance.DumpComputerStatus)
{
OutputTasks.AddComputerStatus(new ComputerStatus
{
ComputerName = computer.DisplayName,
Status = ((NetApiStatus)taskResult).ToString(),
Task = "NetWkstaUserEnum"
});
}
return(sessionList);
}
var iterator = ptrInfo;
if (Options.Instance.DumpComputerStatus)
{
OutputTasks.AddComputerStatus(new ComputerStatus
{
ComputerName = computer.DisplayName,
Status = "Success",
Task = "NetWkstaUserEnum"
});
}
for (var i = 0; i < entriesRead; i++)
{
var data = (WKSTA_USER_INFO_1)Marshal.PtrToStructure(iterator, workstationInfoType);
iterator = (IntPtr)(iterator.ToInt64() + Marshal.SizeOf(workstationInfoType));
var domain = data.wkui1_logon_domain;
var username = data.wkui1_username;
//Remove local accounts
if (domain.Equals(computer.SamAccountName, StringComparison.CurrentCultureIgnoreCase))
{
continue;
}
//Remove blank accounts and computer accounts
if (username.Trim() == "" || username.EndsWith("$") || username == "ANONYMOUS LOGON" || username == Options.Instance.CurrentUserName)
{
continue;
}
//Any domain with a space is unusable (ex: NT AUTHORITY, FONT DRIVER HOST)
if (domain.Contains(" "))
{
continue;
}
var(rSuccess, sid, _) = await ResolutionHelpers.ResolveAccountNameToSidAndType(username, domain);
if (rSuccess)
{
sessionList.Add(new Session
{
UserId = sid,
ComputerId = computer.ObjectIdentifier
});
}
else
{
sessionList.Add(new Session
{
UserId = $"{username}@{Helpers.NormalizeDomainName(domain)}".ToUpper(),
ComputerId = computer.ObjectIdentifier
});
}
}
return(sessionList);
}
finally
{
if (ptrInfo != IntPtr.Zero)
{
NetApiBufferFree(ptrInfo);
}
}
}
/// <summary>
/// Wraps the NetSessionEnum API call with a timeout and parses the results
/// </summary>
/// <param name="computer"></param>
/// <returns></returns>
private static async Task <List <Session> > GetNetSessions(Computer computer)
{
var resumeHandle = IntPtr.Zero;
var sessionInfoType = typeof(SESSION_INFO_10);
var entriesRead = 0;
var ptrInfo = IntPtr.Zero;
var sessionList = new List <Session>();
try
{
var task = Task.Run(() => NetSessionEnum(computer.APIName, null, null, 10,
out ptrInfo, -1, out entriesRead, out _, ref resumeHandle));
//10 second timeout
if (await Task.WhenAny(task, Task.Delay(10000)) != task)
{
if (Options.Instance.DumpComputerStatus)
{
OutputTasks.AddComputerStatus(new ComputerStatus
{
ComputerName = computer.DisplayName,
Status = "Timeout",
Task = "NetSessionEnum"
});
}
return(sessionList);
}
var taskResult = task.Result;
if (taskResult != 0)
{
if (Options.Instance.DumpComputerStatus)
{
OutputTasks.AddComputerStatus(new ComputerStatus
{
ComputerName = computer.DisplayName,
Status = ((NetApiStatus)taskResult).ToString(),
Task = "NetSessionEnum"
});
}
return(sessionList);
}
var sessions = new SESSION_INFO_10[entriesRead];
var iterator = ptrInfo;
for (var i = 0; i < entriesRead; i++)
{
sessions[i] = (SESSION_INFO_10)Marshal.PtrToStructure(iterator, sessionInfoType);
iterator = (IntPtr)(iterator.ToInt64() + Marshal.SizeOf(sessionInfoType));
}
if (Options.Instance.DumpComputerStatus)
{
OutputTasks.AddComputerStatus(new ComputerStatus
{
ComputerName = computer.DisplayName,
Status = "Success",
Task = "NetSessionEnum"
});
}
foreach (var session in sessions)
{
var sessionUsername = session.sesi10_username;
var computerName = session.sesi10_cname;
if (computerName == null)
{
continue;
}
string computerSid = null;
//Filter out computer accounts, Anonymous Logon, empty users
if (sessionUsername.EndsWith(
"$") || sessionUsername.Trim() == "" || sessionUsername == "$" || sessionUsername ==
Options.Instance.CurrentUserName || sessionUsername == "ANONYMOUS LOGON")
{
continue;
}
//Remove leading backslashes
if (computerName.StartsWith("\\"))
{
computerName = computerName.TrimStart('\\');
}
//Remove empty sessions
if (string.IsNullOrEmpty(computerName))
{
continue;
}
//If the session is pointing to localhost, we already know what the SID of the computer is
if (computerName.Equals("[::1]") || computerName.Equals("127.0.0.1"))
{
computerSid = computer.ObjectIdentifier;
}
//Try converting the computer name to a SID if we didn't already get it from a localhost
computerSid = computerSid ?? await ResolutionHelpers.ResolveHostToSid(computerName, computer.Domain);
//Try converting the username to a SID
var searcher = Helpers.GetDirectorySearcher(computer.Domain);
var sids = await searcher.LookupUserInGC(sessionUsername);
if (sids?.Length > 0)
{
foreach (var sid in sids)
{
sessionList.Add(new Session
{
ComputerId = computerSid,
UserId = sid
});
}
}
else
{
var(success, sid, _) =
await ResolutionHelpers.ResolveAccountNameToSidAndType(sessionUsername, computer.Domain);
if (success)
{
sessionList.Add(new Session
{
ComputerId = computerSid,
UserId = sid
});
}
else
{
sessionList.Add(new Session
{
ComputerId = computerSid,
UserId = sessionUsername
});
}
}
}
return(sessionList);
}
finally
{
if (ptrInfo != IntPtr.Zero)
{
NetApiBufferFree(ptrInfo);
}
}
}