Our club has a account to a webservice what does not allow, that more than one user is logged-in at the same time (we all use the same credentials).
Technically it's possible that 2 users are logged in at once, but the general terms of the service tells, that we will be terminated, if they notice that.
I am searching for some kind of proxy service in between user and service, that
asures, that only one user connect at the same time.
(best one i can install on a linux server)
can squid do that?
Related
I am using powershell to get audit fail events 4625 and 4771 from the Domain Controllers. Most of these are 0x18 Status. Now i understand the events with usernames (don't end in a $) as having bad passwords from a machine. Most of the google examples show 4771's from users.
What i want to understand, is what it means when it is coming from a machine?
i.e. surely it is an account on the machine which has an issue, how does a machine have a bad password? And if it can, how does one find out what the issue is ?
Active Directory is an identity management system, and so anything that authenticates with Active Directory needs an "identity" of some sort. Since computers themselves can be joined to a domain and must authenticate against it (with a username and password via Kerberos the same as a regular user logon), they have a username. The AD machine account username is the computer's DNS hostname followed by a dollar sign, for example: Desktop-AB123$
Since every computer in the domain must authenticate against the domain with a username and password, it is possible for that authentication to fail. And it can fail for all of the same reasons that a regular user logon can fail: unrecognized or misspelled username, incorrect password, wrong domain or UPN suffix, or any number of authentication errors.
Event ID 4771 indicates a Kerberos preauthentication error and status 0x18 (usually) indicates a bad password. Source.
Machine accounts renegotiate their password automatically with the Domain Controller when they connect to the domain. If a domain-joined workstation is unable to communicate with a domain controller long enough for the password to expire, it will not be able to log in and you will get a failed logon for that computer's machine name. The computer will need to be rejoined to the domain (or have its password reset using Reset-ComputerMachinePassword and a domain admin credential). The same is also true if a domain controller is unable to communicate with the PDC Emulator. This will be the most common type of error that will lead to failed machine account logins. The second most common will probably be due to computers being renamed while unable to contact a DC, changing the computer's logon username without updating AD.
Beyond password expiration or computer renames, you have to start looking deeper for root causes. These are likely going to be Kerberos negotiation errors caused by services attempting to authenticate in order to perform certain actions. Note that the authentication error does not necessarily occur at service start and may occur when the service is accessed or triggered by another application. I recommend reviewing my question & answer in ServerFault regarding one such example where a server's DNS name didn't match its NETBIOS name, which caused Kerberos authentication to fail and fall back to NTLM.
As that ServerFault question illustrates, tracking down the root cause of a failed machine logon, once you've ruled out username and password errors, can be extremely difficult. Your first step should probably be to enable Netlogon debug logging and then searching the netlogon log file for your failure events. You can also search the SYSTEM event log for any events related to services failing to start. After those two starting points you're basically on your own and will need to develop some advanced troubleshooting and investigation skills to track down the root cause.
One final note, your question is not exactly related to programming or software development, so SuperUser or ServerFault might be a better place for questions such as this in the future. ServerFault is geared towards professional sys admins working in production environments while SuperUser is more geared towards hobbyists, enthusiasts, home servers, and DIYers.
I need to be able to store a user's Exchange password so I can use it to perform some task later on, using EWS. I know storing passwords in plain text is a horrid crime, so what options do I have?
In my case, my application will have access to an administrative account that will have the ability to use impersonation to work with users' Calendars. I need to store the password of this admin account so I can use it while authenticating with the Exchange server at a later time. I am not planning on using the EWS Managed API.
I have a user that created a calendar app with similar requirements. By default, an account that has these permissions globally is horrible and not recommended. Impersonation roles were granted by department that required access to the app to reduce risk scope. However if you require this globally, here's what I recommended for mitigating the account/password exposure:
Restrict the accounts functionality to Exchange services only. Features like log on locally and other general domain user privileges are not needed for an EWS service account that only needs mailbox access and impersonation roles. In this case, the account cannot log onto a computer nor can it be used for RDP. This limits exposure for malicious use.
The user/pass can be stored in your applications database and the connection string would also be stored outside of your application, there's a lot here: https://security.stackexchange.com/questions/22817/how-to-encrypt-database-connection-credentials-on-a-web-server and encrypting the password within the database; further reading: http://www.darkreading.com/safely-storing-user-passwords-hashing-vs-encrypting/a/d-id/1269374
Restrict DB server and management access. This is a larger issue than it should be if the database server is shared between groups. Audit the database server access, and re-restrict if you have too many cooks in the kitchen. The database server should also not be directly accessed by user networks but that may be a larger issue to tackle.
Restrict access to the application. As in, is it available externally or only available inside your perimeter? Either way, the application should also include authentication just to access, using Kerberos or some other SSL auth, make sure the application cannot be used to DoS the EWS services from over-access.
Create a one-off throttling policy on Exchange for this user and assign accordingly to prevent the application from breaking EWS or limiting regular user functionalities. This is something Blackberry admins learned the hard way if they didn't follow recommendations. When BES server wouldn't properly tear down connections, web services would start dropping valid client requests. As such BES had to instruct users to create a one off throttling policy for various Exchange features. I did the same for the user that created my EWS app. And a few times it saved me.
Really it will boil down to good application design and coordinating requirements with the Exchange team.
Don't's:
Don't store the username/password in Apache/IIS pages or the connection string
Don't grant global permissions for the account if you don't have to
Don't allow unauthenticated access to the application and allow unlimited connection times
Hope this helps.
I have problem with creating service that has access to files on network disk.
Service must have admin rights and it will be run by users that don't have admin privileges.
I send path as UNC
and file is seen by service but it return ACCES_DENIED errors when try to open or do anything on Network drive.
When I run my service as server , everything works fine.
I try to find answer but everywhere I can found only partial answers that do not help me at all.
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I read that standard service logged as SYSTEM can't have access to network.
So i tried to log id as
NetworkService, LocalService
It didn't work. After run it as one of those user my service can't save files on c:
Some kind of admin account.But I didn't manage to success on that.
Actually logged user.
I don't know how to get password for current user.
Still this will not work for user without admin rights.
========
Please tell me what can I do?
There are plenty of Services that use somehow network resources. How do they do that?
You need to configure your service to run as a user which has sufficient rights. In this case you are looking for rights to network shares. Typically that's going to need a domain user with appropriate rights. Normally you'd ask your network manager to create a dedicated user account for the purpose.
You appear to be labouring under some false information as to how services work. You talk about running the service under the account of the logged on user. Remember that services run when there are no users logged on. And remember that there may be multiple logged users at any point in time.
For me, the port was getting blocked through firewall, I had to add a inbound rule and specify the port which i was using in my application. This way firewall did not blocked my port for outgoing connections.
References:
https://www.firehousesoftware.com/webhelp/FH/Content/FHEnterprise/FHEnterpriseInstallationGuide/24_StaticPort.htm
I have an application server (webservice or remoting, not yet decided) on a remote machine and a client on the same domain. I want to authenticate the user as a domain user on the server.
I can ask the user to enter their Windows username/password and send those to the server and get the server to check them against Active Directory but I would rather not. Is there any way I can get the client to send some kind of token which the server can then use to identify which domain user is sending it a request? Obviously I want to protect the server against someone sending a fake user ID and impersonating another user.
Clarification
The client on computer A will communicate with the server on computer B. I think I will probably using .NET remoting for this communication. On the server I merely need to know the ID of the user on computer A; if the app on computer A must send the ID I need to be sure that it hasn't sent the ID of a different user.
I don't need to impersonate the other user, I merely need to know (for certain) who it is.
Are you saying that the client communicates against your server, and you need to use the client's privileges at a third server? That scenario describes The Double-Hop Problem. The blog most describes it in detail, and what can be done to circumvent it (domain modifications).
[...] you can get around the problem and use proper delegation if you set up your network to use Kerberos and set up the web server in question as trusted for delegation.
Added:
I know of no way you can identify the user on computer A. Would it be enough if it was just the user executing your program? You could use windows authentication in a domain scenario, but that would only give you the privileges used by the program to authenticate, which may differ from the actual evil user in front of the keyboard.
Added:
Your comments to this post indicates that windows authentication with impersonation would work for you. Check http://community.bartdesmet.net/blogs/bart/archive/2006/08/26/4277.aspx for code examples.
My question is pretty much summed up in the subject.The context is a problem we are facing with the account getting locked our fairly often.
My setup uses this as the service acccount for clearcase application.
There is another account by the same name (but in a different domain - a trusted domain) that runs a monitoring sofftware under this account. For eg., my setup uses the accoundt DOMAINA/clearcase_albd, while this other trusted domain runs a batch file under TRUSTEDDOMAIN/clearcase_albd.
We are suspecting this account to be causing the locking out of our service account (but at this point have not yet figured out why!)
Have pored over event logs endlessly, to no avail and have now decided to start fresh from ground zero.Am following a thread of thought and the first thing I need confirmation on is this:
Should I be seeing DOMAINA/clearcase_albd account when i run clearlicense at all?
If not, then why would another account by SAME name but from a different domain lock out my domain account?
Would greatly appreciate any help in this regard,
Thanks in advance
According to the IBM ClearCase Manual, the Rational® ClearCase® albd_server program runs with the identity of a special user account known as the Rational ClearCase server process user.
This user is a member of the Rational ClearCase administrators group, which grants privileged user status.
That account should not directly uses a license, as it is related to the albd (Atria Location Broker) process which will execute operation on behalf other users.
When a client program needs access to a service (a VOB or view server, for example) on a Rational ClearCase server host, it uses a remote procedure call (RPC) to send a request to the albd_server process on that host.
The albd_server starts the requested service if it is not already started, and provides the service’s port number to the client. Thereafter, the client communicates directly with the service.
IBM does suggest two albd accounts, for central VOB/view servers and end-user workstations. This is primarily done to prevent albd account issues (account lockouts, etc) on the albd account from impacting the VOB servers themselves.
BUT: those accounts should be on the same domain.
Note: by typing
creds clearcase_albd
You will see its SID for the current Windows domain.
You will then be able to check if that SID pops up in the clearlicense command output.