I create grouped managed service account gMSA by running command New-ADServiceAccount and I specify -PrincipalsAllowedToRetrieveManagedPassword. At the very moment of creation I am able to use gMSA on computer which is specified as -PrincipalsAllowedToRetrieveManagedPassword.
What is the purpose of Install-ADServiceAccount? I have found many blogs where people say to run it but nobody explains reason why to do it.
I am not doing it and everything works fine.
Install-ADServiceAccount is used for installing/linking an MSA to the computer so it's available to be used. This is needed because MSA have a one-to-one relationship with a computer. It does not apply to gMSA which can be shared. gMSA only require you to set the permissions using New-/Set-ADServiceAccount
How to use gMSA: https://technet.microsoft.com/en-us/library/jj128431.aspx
Related
I have created a gMSA like this:
New-ADServiceAccount -name Cust00000 -DNSHostName Cust00000.domain.com -PrincipalsAllowedToRetrieveManagedPassword "IIS_IUSRS" -ManagedPasswordIntervalInDays 60
And life seems to be good. However, when I run
Test-ADServiceAccount Cust00000
This is what I get:
False
WARNING: Test failed for Managed Service Account Cust00000. If standalone Managed Service Account, the account is
linked to another computer object in the Active Directory. If group Managed Service Account, either this computer does
not have permission to use the group MSA or this computer does not support all the Kerberos encryption types required
for the gMSA. See the MSA operational log for more information.
I checked event viewer -> Application and Services Logs -> Microsoft -> Windows -> Apps -> Microsoft-Windows-TWinUI/Operational but this does not appear to be correct. Where (and possibly what) is the MSA operational log?
EDIT: For the overall issue, I had tried Install-ADServiceAccount but it wasn't working. I gave up on that and finally got it working (for a gMSA named Domain\sirdank$) with Set-ADServiceAccount sirdank -PrincipalsAllowedToRetrieveManagedPassword "$env:computername$" I've also had luck with passing "Domain Computers" instead of "$env:computername$".
Having a similar issue right now. I think the log you are looking for is in Event Viewer under Microsoft/Windows/Security-Netlogon/Operational log; you might see some 9001/9002 events (Task Category of MSA) which might give you some color on what is happening.
Got this from a recent TechNet blog post that describes troubleshooting gMSA account creation/testing issues. Take a look, it might be relevant to your overall issue: https://blogs.technet.microsoft.com/joelvickery/cannot-install-service-account-the-provided-context-did-not-match-the-target/
Alternate link (it appears the same post was cross-posted with a different title): https://blogs.technet.microsoft.com/runcmd/the-rc4-removal-files-part-1-whats-in-an-error-message/
Today, I was able to create totally random and invalid SPN using the setspn command, but I dont understand why invalid SPNs are allowed. For example:
setspn -s RandomSvc/randomname.random.random valid_user was run successfully for valid_user in my domain (I substitute the actual user name here, but the user is a valid user in the domain).
Then if I do setspn -l valid_user, it will list this invalid entry.
I guess nobody can actually connect to this service since it does not exist. however, if I try to add a valid SPN, but typed it by mistake, I won't notice it until my application gives me an error. So why setspn does not do any validation (other than checking for duplicate with -s)?
The setspn command won't stop you from creating an invalid SPN, and for good reason, so there is no actual problem here believe it or not. Your definition of a valid SPN - that of a representation of an actual service running on an actual machine having a host name in DNS which can be reached over TCP/IP, is not going to be enforced by setspn for reasons I am about to describe. According to a KDC, while an SPN represents an actual service running on an actual machine having a host name in DNS which can be reached over TCP/IP, it doesn't actually have to be real at the time though. Here's why. Have you considered the case where perhaps the service, or even the machine it will be run on, will be installed later? The service and even the machine it is running on, and the DNS entry for said machine, doesn't have to be in place in the here and now when you create the SPN. Setspn.exe is simply a rudimentary tool which exists that allows you to create SPNs which will conform the RFCs for Kerberos. Its up to you to architect it right though, it's not going to hold anyone's hand in the process. I work for a large company and create SPNs all the time for services, and even for machines, which do not yet exist. That way the Developers or sys admins don't have to contact me to have an SPN created after the fact. They are following a project plan and savvy managers are going to have the SPN, DNS entires, IP addresses for machines, all planned out and created ahead of time before the OS admins get around to actually spinning up a live server for such use. So if setspn prevented people from creating an SPN for a service which is not yet up and running, there would be some very angry system admins out there. That is why it is allowed to create "invalid" SPNs, when you think it shouldn't. If you want something to do extra layers of validation not afforded by the generic setspn.exe, to catch mistakes before your application does, then you will have to create such a thing yourself. Ask yourself though, is this worth the time for something so specific? I mean, how often are you creating SPNs? This should all make sense to you now. I periodically run a setspn -X to catch duplicate sin my domain. I've never had the time, but I suppose I could also list out all the current SPNs in the domain and check if they are each currently valid, and take corrective action if they weren't. I'm sure there are probably more than a few which no longer are active. I don't consider it that big of a deal.
I am encountering several situations where, in a Chef recipe with powershell_scipt, a command appears to fail, whereas if I run the same command in powershell outside of Chef, the same command works.
The two in particular are "regedit", which I am trying to use to set a key for app compatibility and the other is "net use z:...." to created a mapped drive. Both of these seem to work fine if I run them in powershell, but if I use them inside a recipe inside powershell_script, they don't appear to do anything.
So I'm wondering is this because Chef runs commands that are inside powershell_script at some lower privilege level?
Also if so, how do I change it so that the regedit and net use would work?
Thanks,
Jim
EDIT 1: This seems to work for adding the registry entry I needed:
registry_key "HKEY_CURRENT_USER\\Software\\Microsoft\\Windows NT\\CurrentVersion\\AppCompatFlags" do
values [{
:name => "{2b9034f3-b661-4d36-a5ef-60ab5a711ace}",
:type => :dword,
:data => 00000004
}]
action :create
end
That prevents the compatability popup that I am getting when we run the Sharepoint installer.
EDIT 2: I hope that this is ok, but for the record and more visibility and hope that I remember this, I found this re. mapping drives in Windows and Chef:
Mount windows shares on a windows node with Chef
and:
https://tickets.opscode.com/browse/CHEF-1267
I haven't tried that yet, but that seems like the answer to my drive mapping need.... hopefully..
The chef client service runs as Local System (SYSTEM) by default.
In Windows, that user has full privileges on the local system, like root basically, but on the network it authenticates as the computer object.
So it you are trying to use regedit to change something in for example HKEY_CURRENT_USER then you need to remember that the code will not see the same "current user" as you will when you run it in interactively. Also, regedit is an .exe; you should really do what you need through the PowerShell providers or .Net objects.
For net use you are trying to map a drive. It's likely that the computer account doesn't have the rights to the share that your user has. Again, net.exe is a separate executable. net use maps a drive to a drive letter (usually) and you shouldn't be doing that in a configuration script, in my opinion. You should access the UNC path directly, but either way I still think that you're probably running into a permissions issue here.
You could change the credentials of the service to use a user account that has all the rights you want, but before doing something like that you should consider changing your workflow to not need that.
I have a bunch of PowerShell scripts that call out to external programs to perform certain actions (no choice about this). I'm trying to find a way to allow users to connect to a constrained remote session using delegation to run these scripts (and the external binaries) as a privileged account, WITHOUT the user being able to execute the binaries with the privileged account.
I've found that if I constrain the endpoint using NoLanguage and RestrictedRemoteSession, or using a startup script to remove access to those parts of the system that it breaks the scripts because they're no longer able to execute the binaries.
Is there any possibility of making this work, or will I have to rewrite my existing scripts as DLL cmdlets which could then make the calls to the external binaries (or write just a proxy command in a DLL to make the calls)?
Create scheduled tasks without a trigger, configure them to run as a privileged user, and have your restricted users start them from the Task Scheduler.
You are looking for JEA or Just Enough Admin. It does exactly what you are trying to do with restricted endpoints.
http://blogs.technet.com/b/privatecloud/archive/2014/05/14/just-enough-administration-step-by-step.aspx
Start with the video. Jeffery Snover may give you the details needed to make your solution work as he explains step by step how JEA was built.
I am DBA. I am trying to write bunch of scripts that I could execute from one central server. Ideal would be to send all the scripts from central server to say 50+ servers across multiple win domains (for databases management purposes).
The problem I am running into is - security. Seems like PowerShell Remoting is the way to go. But when I send a script to another server, I get 'not digitally signed' error.
I could 'self sign'. But that cert if only trusted on local machine. So that option is out.
Maybe Certificate Authority is a way to go. Or adding trusted hosts. I just have no clue on this one, so if you know any blog posts or how to do this - it would be big help.
Well, it's a security risk, but there's always the possibility of setting the execution policy to RemoteSigned, keeping a local repository on each server and calling those as needed via PS-Remoting. I don't like that idea one bit though.
If you are doing remote execution, you will need to sign your scripts. A detailed step by step can be found here. It even covers deploying the cert via GPO so that it's domain trusted.
I would use PowerShell remoting. This would allow you to run it as remote commands instead of remote scripts. If you catch the bottom of this SimpleTalk article, after "Persistent Sessions". It shows the option of executing a set of commands against each server instead of the script. This should prevent having to deal with the remote signed issue and provide a little more control.
The only thing to deal with on remote sessions is your credentials. I have not tried this on multiple domains but a few stand-alone servers.