Access to the port 'COM4' is denied - asp.net

I am using arduino (some micro-controller), and I made an ASP.net page to communicate with it. I connected arduino to serial-port COM4. When I run the ASP.net website, I get the following error:
Exception Details: System.UnauthorizedAccessException: Access to the port 'COM4' is denied.
ASP.NET is not authorized to access the requested resource. Consider granting access rights to the resource to the ASP.NET request identity. ASP.NET has a base process identity (typically {MACHINE}\ASPNET on IIS 5 or Network Service on IIS 6 and IIS 7, and the configured application pool identity on IIS 7.5) that is used if the application is not impersonating. If the application is impersonating via , the identity will be the anonymous user (typically IUSR_MACHINENAME) or the authenticated request user.
To grant ASP.NET access to a file, right-click the file in Explorer, choose "Properties" and select the Security tab. Click "Add" to add the appropriate user or group. Highlight the ASP.NET account, and check the boxes for the desired access.
now i know it may sound like the solution is right there: " to grant asp.net access to..." but i don't know what file they are talking about!
So please can anybody point out the solution ?
PS: I first did a windows form application and it worked. So there is nothing else using the COM4.
Thanks in advance.

Ignoring that it's strange that a web application should talk to a COM port on the server, the issue is as follows: by default an ASP.NET application in IIS runs under a low privilege user (as specified in the error message). That user is not allowed to access the port.
A console application runs under the user who launched it. I'm assuming that's you and you're an admin on the machine.
To get the ASP.NET doing the same open IIS (Start - Run - inetmgr), select 'Application Pools', choose the app pool under which your web application is running, click 'Advanced Settings', set the 'Identity' field to your user.
Restart the app pool and launch the web application.

Related

The pipe name could not be obtained for the pipe URI: Access is denied

I am getting an "Access is denied" error on a 2012 R2 server when my web app on that server tries to access a self-hosted WCF service on that server using named pipes.
I do not have this issue on my development machine (Win 7). I can access the WCF service via the client test app on both the server and my development machine.
If I enable ASP.NET Impersonation on the web site using a user account that has full control permissions to the install folder for the WCF service, then the error goes away. I do not want to use impersonation since I understand it has significant performance penalties (not to mention security issues) and the WCF service is called for every user input during a session.
The strange thing is... If I set the app pool to run as either the user with rights to the service folder as described above or as a user with admin privileges, then I still get the error if ASP.NET Impersonation is disabled. The error will go away only after I enable ASP.NET Impersonation on the web site.
I do not have access to the source for the WCF service.
In this case, the web app was located on the D:\ drive and the Anonymous Authentication user (IUSR) did not have RX permissions to the web app location.
Note that if you are using Windows Authentication, then the same issue occurs if the Windows Authenticated user does not have RX permissions to the location of the web app.
The problem was resolved once I gave the authenticated user the proper permission.
Sometimes the solution really is just plain simple...
"Ain't got no gas in it" - Slingblade.

Can't get rid off "Login failed for user IIS APPPOOL\NETWORKSERVICE"

I'm trying to access a sql server database from an ASP NET app configured to work with IIS.
I have several questions now,
1) Authentication in IIS: I need to know if my authentication settings for the site are ok:
I tried with Windows Authentication set to Disabled, but the problem continues.
2) Are the settings for the user NT AUTHORITY\Sericio de red well configured? ("Servicio de red" means Network Service)
3) When I added the login for network service, I only found "Servicio de red", I guess it's the equivalent for NetworkService, I'm I right?, My windows 7 ultimate is an spanish version, I just changed the windows interface by using a windows upgrade to make it appear in english. Is there a problem with it?, I guess it's right because the access to the database is being done through the IIS APPPOOL\Servicio de red user.
My DefaultAppPool identity is set to to AppPoolIdentity
If you want to see what I have tried, see this thread.
The whole project, along with a backup of the database I'm using can be found here, called MyServiceSolutionInIIS
What I'm trying is to build a WCF Data Service that offers information that comes from an entity data model generated from a sql server database. This service will be used by a WPF App as a client.
I'd like to avoid creating a user for it, I think it can be done with the App Pool
Okay so the way this works is, whatever application pool your endpoint is running under passes its credentials to the SQL Server. So, you have two options:
Run the default application pool under NetworkService, or;
Use SQL Authentication when connecting with your web service to the SQL Server.
Honestly, the latter is the most common, but in your situation you may be just fine by changing the default application pool to run under NetworkService.
This has nothing to do with the authentication you've chosen (well, mostly nothing.. you can control which credentials anonymous users run under). Every website runs in an app pool, and this app pool has an AppPoolIdentity.
I'm a little confused as to why it would be claiming it's IIS AppPool\NetworkService, since NetworkService should be NT AUTHORITY\NetworkService, or IIS AppPool\MyAspService or IIS AppPool\DefaultAppPool.
There is a lot more information on App Pool Identities here:
http://www.iis.net/learn/manage/configuring-security/application-pool-identities
Note: There is a bug in IIS 7.5 (the version of IIS that comes with Windows 7 and Windows Server 2008 R2) that sometimes causes authentication problems with AppPoolIdentities if the users password changes (say, if you have mandatory password change policies). There is a hotfix here:
http://support.microsoft.com/kb/2545850/en-us
More info here:
IIS application using application pool identity loses primary token?
There so many scenarios in which this issue occurs.
First thing you need to clear if you are using windows authentication and you are not mentioning any username password in your connection string then:
What happens when you run your code through localhost: when you run your wcf test client from localhost, it will be able to communicate to database as local debug mode application is calling database by your account's service. So it has access to database because devenv.exe is running under your user account.
But when you deploy your web service in IIS. Now understand this service runs under IIS not under your account. So you need to assign access rights to IIS service to access the sql server for windows authentication. Here your web service would not be able to communicate to the SQL server because of access rights issue and Login Failed for user_______ (here your user will come)
So if you are using windows authentication to connect your database, you just have to change the IIS Application pool settings. You need to change IIS Application pool's identity to:
local System (for single windows user).
Network Service (for intranet users or domain users)
Below are the Steps for windows authentication WCF:
•Open IIS (windows+R (run) then type inetmgr, then click ok)
•double click your PC name under Connections
•Click Application Pools
•Select your app pool (DefaultAppPool)
•Then under actions on the right click Advanced Settings:
•Go to Process Model section and
•click on Identity.
•Now select LocalSystem (for single windows authentication user).
or select Network Service (for Intranet users)
Now open your sql server management studio: open run-> then type ssms then press ok in ssms, login using your windows authentication account. open security tab expand logins tab then you will be able to view your account.
Now open properties of your account go to userMapping then select the database you want to connect then check the role membership services you want to use for the selected database click ok. (For network services i.e. intranet users you need to configure above settings for NT AUTHORITY\SYSTEM user too)
add Trusted_Connection=True; property in your connection string. Save it & deploy the web service. Restart app pool.
you will be able to connect the database now.

Does an IIS 7.5 web app with windows authentication require end users to have file permissions?

Short version:
For IIS 7.5 web applications with Windows Authentication does the end
user need to have Read file access?
Long version:
I have an intranet ASP.NET web app that uses windows authentication. It's installed at dozens of different companies and normally the authentication works fine: users navigate to the site e.g. http://appserver/MyApp, the app recognizes who they're logged in as and displays pages accordingly. I just installed it at a new client and encountered a problem:
When connecting e.g. to http://appserver/MyApp I'm prompted for windows credentials but after entering them I'm repeatedly prompted. After several re-entering credentials I'm shown a 401 error page saying "401 - Unauthorized: Access is denied due to invalid credentials.". So not only is it not passing through my identity but even when entering the username & password it's still denying access.
Giving Read & Execute permissions to the end users of the app solves this problem, but I don't think this should be necessary at all.
In the windows Application Event Log there's a message "File authorization failed for the request" along with Thread account name: NT AUTHORITY\NETWORK SERVICE and User: [the correct workstation users's domain account]. This suggests that the file access is being performed with the User's identity, not the AppPool identity of Network Service. Sure enough if I grant the end user Read & Execute permission (I didn't try Read only) to the application's directory then everything works correctly: when the user browses to the site they're authenticated automatically, not prompted, and the web site correctly recognizes their identity! Therefore my workaround solution is to give Read & Execute permission to Everybody on the application directory...but this is not an ideal solution.
This seems very strange. I've never needed to do this before in IIS 7.5, so far as I recall, and definitely never needed to in IIS 6 or IIS 7. Is this a new IIS7.5 thing? The documentation says that Impersonation is turned off by default. I added a element to the web.config to be sure, removed file permissions other than Network Service, but the problem remained.
Any thoughts? Is it normal for Windows Authenticated sites on IIS 7.5 for end users to need file permissions on the web server files?
Some relevant details:
Network Service
has Full Control file permissions to the app folder.
When connecting from the server itself I was prompted for credentials
but after entering them i'm authenticated and the application works
correctly including displaying my windows login and connecting and
retrieving data from the db. I later determined that it was prompting
for credentials because http://localhost was in the trusted sites
and therefore not recognised as the Intranet Zone and thus not
passing identity through. I also determined that it was working as
this user identity because it's an admin user who has file
permissions.
The web server is running Windows Server 2008 R2 / IIS
7.5. It didn't have IIS on it until I installed it. I installed the default features as well as Windows Authentication, ASP.NET, and
possibly a couple of other items. A separate WCF app I installed that
uses IIS, anonymous authentication & .net 2.0 is working fine on
that web server.
The app install process is a manual copy of files,
creation of IIS App Pools & web apps, updating connection strings,
etc.
I checked the IE security settings. It was recognizing the
server as in the Intranet zone and had the option 'Automatic logon
only in Intranet zone' selected. Also on Advanced Settings the
'Enable Integrated Windows Authentication' option was checked.
After
installing IIS I ran aspnet_regiis -i for .net 2.0 and
aspnet_regiis -iru for .net 4.0.
Anonymous authentication is
disabled for my app and Windows Authentication enabled.
The app is
running on ASP.NET v4 but there's another app I installed
experiencing the same issue running ASP.NET v2.
The app is running
with Identity = Network Service and in 32-bit mode.
Database
connection string includes Trusted Connection=True and database
permissions are granted to the web server account [domain]\[server]$
e.g. DGM\MyServer$.
In IIS > Authentication > Windows Authentication > Providers the list was Negotiate first then NTLM. I tried reordering so NTLM is first.
In the Windows Security Event Log there
were a series of Microsoft Windows security auditing events: Logon
and Logoff. They indicated that the Logon was successful and was
displaying the User Id of the workstation user. This are from when
I'm connecting from another workstation and receive a 401
Unauthorized after several attempts.
I see someone has had this problem reported here but with no solution. Originally I posted in the ASP and then the IIS forums with no answers so far.
Update:
This msdn article says
When Windows authentication is enabled but impersonation is disabled, ASP.NET performs file access checks in the file authorization module using the credentials that are sent from the browser (my emphasis). Impersonation does not need to be enabled, because the FileAuthorizationModule module ensures that the requesting user is allowed read access or write access to the resource, depending on the request verb (for example, GET or POST) before executing the request. This behavior applies to any requests that enter managed code. In earlier versions of ASP.NET, accessing files based on URIs such as "Default.aspx" triggered the access check. In ASP.NET MVC applications, where access to resources is typically performed using extensionless URLs, this check typically does not apply, because there is not a physical file to check. In that case, the FileAuthorizationModule class falls back to checking access-control lists (ACLs) for the folder.
This does suggest that the end user needs permissions to the files (in the case of .aspx) or the folder (for MVC) ... although still this seems slightly tucked away and non-definitive. This article about App Pools says they're used as the identity for securing resources, which contradicts the idea of needing to grant privileges to end users. Unless the rules are different for App Pools and NETWORK SERVICE, which could be the case but would be surprising.
Are authenticated users allowed to the app folder?
We were also fighting with this issue, and started setting up security groups so we could give our users file level permissions. Then one of our server admins stumbled across a couple of new properties that allow the app to authenticate to the file system under set credentials, and resolved the need for the users to have access. Here is what he came up with…
There are two IIS settings that control this:
Physical Path Credentials Physical Path Credentials Logon type
By default, Physical Path Credentials is set to Application User
(Pass-through authentication). This means that IIS doesn’t do any
impersonation when handling Windows Authentication requests. This can,
however, be set to a specific user (though not, unfortunately, the
application pool identity, which would be ideal). Physical Path
Credentials Logon Type is set by default to Clear-Text. For my testing
I set this to Interactive (though this may not be the correct value).
Possible values are Clear-Text, Batch, Interactive, and Network.
To set this up I did the following:
Created a local account (IIS-AccessUser)
Granted IIS-AccessUser read and execute access to the /home directory of the site.
Added IIS-AccessUser to IIS_IUSRS group (necessary for accessing .NET temporary files)
Set IIS-AccessUser as the Physical Path Credentials
Set Physical Path Credentials Logon Type to Interactive
Doing the above allowed me to log in to the application directly,
without having to allow Authenticated Users, or me having to be a
member of any of the groups in the /home folder. It also still
preserved .NET Authorization roles, so I still could not access parts
of the site that I was not allowed to.
The short answer is NO. You are not required to grant file access permissions when using Windows Authentication in IIS 7.0 and IIS 7.5.
We were only able to discover this because our server admin smelled the security and management issues that arise from taking the route of granting file level access to users and groups.
For anyone dealing with this issue or if you are setting up a new IIS7/IIS7.5 server and/or moving from IIS 6, here is an article that gives you all of the Windows Authentication options and configurations that need to be modified to avoid granting file level access to individuals or groups.
Please read the two comments in at the end of the POST for some valid critiques of the methods used in this article.
http://weblogs.asp.net/owscott/iis-using-windows-authentication-with-minimal-permissions-granted-to-disk
In addition to the information in the article, please be aware that IIS 7.5 is not using the web configuration tags for system.web (at least not in my MVC 4 application).
It is looking in the system.webserver tags for authorization configuration (where you will need to list the windows domain\groups a user needs to be in to access your application).
-- DSB

Impersonation and delegation (with SQL Server) in ASP.NET

I've written a simple ASP.NET application that works as a frontend for a simple MSSQL database. The application is accessible over the Internet.
There are two physical servers involved: a WS2008R2 Active Directory domain controller which is also running MSQL Server 2008 R2, and another server, the webserver (WS2008R2/IIS7.5) where my application resides.
The Application Pool for my application "FooPool" has its own AD User identity it runs under "FooUser". FooUser does not have any permission to access the SQL Server database, instead only my own personal user account "MyUser" has that permission.
The idea is that attempts to access this web application first perform Windows Authentication with IIS, my web application then uses Impersonation to access the SQL Server database.
However my application does not work.
I tested the application without it touching SQL Server, just to test impersonation, so I did Response.Write( WindowsIdentity.GetCurrent(false).Name ); which correctly shows the application impersonating MyUser and not acting as FooUser. This works from all modern browsers and across the Internet.
But as soon as it touches MSSQL Server I get the error "Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'." but that should not be happening because no user tokens are for Anonymous Logon.
I've done my homework and read all about Delegation and Impersonation in ASP.NET and I have set up delegation: The FooUser account has a Service Principal Name set-up (I set the SPN to an arbitrary string, is that doing it right?) and is marked for delegation in ADUC.
Finally, my connection string has SSPI enabled, Connection pooling disabled, and the network library set to "dbmssocn".
What else am I forgetting?
Finishing the Configuration for Delegation to Work you must enable constrained delegation:
Open Active Directory Users and Computers
Find the user account that the IIS Web site is using for the web application pool and double-click it
Select the option: Trust this user for delegation to specified
services only.
Make sure that the user is constrained to the
SPN associated with the MSSQLSvc service
Restart IIS
http://blogs.technet.com/b/askds/archive/2008/11/25/fun-with-the-kerberos-delegation-web-site.aspx

asp.net: authentication

When I upload my asp.net web application to the server and access to the url link, it is asking for the authentication... if I dont, I got this error message:
ASP.NET is not authorized to access the requested resource. Consider granting access rights to the resource to the ASP.NET request identity. ASP.NET has a base process identity (typically {MACHINE}\ASPNET on IIS 5 or Network Service on IIS 6) that is used if the application is not impersonating. If the application is impersonating via , the identity will be the anonymous user (typically IUSR_MACHINENAME) or the authenticated request user.
To grant ASP.NET access to a file, right-click the file in Explorer, choose "Properties" and select the Security tab. Click "Add" to add the appropriate user or group. Highlight the ASP.NET account, and check the boxes for the desired access.
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
What should I change in the web.config file in order to get this working as locally?
Thanks in advance
Did you make sure you converted the directory to an application in IIS?
Browse to directory in IIS directory tree
Right click and select "Convert to Application"
Select application pool, and convert

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