Retrieving User Account Expiration from ActiveDirectory

Question

I'm trying to retrieve the expiration date from accounts.

I've tried

DirectoryEntry user = new DirectoryEntry(iMem);

var AccountExpiration = DateTime.FromFileTime((int)user.Properties["accountExpires"].Value);

it doesn't work, only gives me the error "Specified cast is not valid".

When I use

var AccountExpiration = user.Properties["accountExpires"];

returns a com object, which I'm unable to read.

Using windows powershell, works fine, I don't get why this wont work...

this is the code I use in powershell

$Expires = [datetime]::FromFileTime($tmpUser.accountExpires)

Solution

You can use the System.DirectoryServices.AccountManagement namespace to accomplish this task. Once you get a UserPrincipal from a PrincipalContext, you can inspect the UserPrincipal.AccountExpirationDate property.

PrincipalContext context = new PrincipalContext(ContextType.Domain);

UserPrincipal p = UserPrincipal.FindByIdentity(context, "Domain\\User Name");

if (p.AccountExpirationDate.HasValue)
{
    DateTime expiration = p.AccountExpirationDate.Value.ToLocalTime();
}

If you do want to use DirectoryEntry, do this:

//assume 'user' is DirectoryEntry representing user to check
DateTime expires = DateTime.FromFileTime(GetInt64(user, "accountExpires"));

private Int64 GetInt64(DirectoryEntry entry, string attr)
{
    //we will use the marshaling behavior of the searcher
    DirectorySearcher ds = new DirectorySearcher(
    entry,
    String.Format("({0}=*)", attr),
    new string[] { attr },
    SearchScope.Base
    );

    SearchResult sr = ds.FindOne();

    if (sr != null)
    {
        if (sr.Properties.Contains(attr))
        {
            return (Int64)sr.Properties[attr][0];
        }
    }

    return -1;
}

Another way of parsing the accountExpires value is using reflection:

private static long ConvertLargeIntegerToLong(object largeInteger)
{
    Type type = largeInteger.GetType();

    int highPart = (int)type.InvokeMember("HighPart", BindingFlags.GetProperty, null, largeInteger, null);
    int lowPart = (int)type.InvokeMember("LowPart", BindingFlags.GetProperty | BindingFlags.Public, null, largeInteger, null);

    return (long)highPart <<32 | (uint)lowPart;
}

object accountExpires = DirectoryEntryHelper.GetAdObjectProperty(directoryEntry, "accountExpires");
var asLong = ConvertLargeIntegerToLong(accountExpires);

if (asLong == long.MaxValue || asLong <= 0 || DateTime.MaxValue.ToFileTime() <= asLong)
{
    return DateTime.MaxValue;
}
else
{
    return DateTime.FromFileTimeUtc(asLong);
}