Custom IPrincipal and declarative security checking

15 Mar 2005 1:29 PM

Baileys

Hi,

I'm having trouble getting declarative checks (using
PrinciplePermissionAttribute) to work with my custom IPrincipal
implementation in a web scenario.

I created a custom principal class (MyPrincipal), implementing the
IPrincipal interface
I added code to the global.asax Application_AuthenticateRequest handler to
construct an instance of MyPrincipal, and assign this instance to
Context.User (also tried assigning the instance to both Context.User and
Thread.CurrentPrincipal).
I've got a class (MyClass) defined as follows:

public class MyClass
{
[PrincipalPermission(SecurityAction.Demand, Role="Admin")]
public static void MyMethod()
{
    // do stuff
}
}

I have got a web page containing the following code in Page_Load:

bool test = Thread.CurrentPrincipal.IsInRole("Admin"); // 1. works (test=true)
bool test2 = Context.User.IsInRole("Admin");               // 2. works
(test2=true)

PrincipalPermission p = new PrincipalPermission(null, "Admin");
p.Demand();                                                            // 3
..Fails

MyClass.MyMethod()                                                // 4. Fails

The last 2 methods (using PrincipalPermission.Demand and calling the
MyMethod) fail with a security exception ( Exception Details:
System.Security.SecurityException: Request for principal permission failed.).

I was under the impression that PrincipalPermissionAttribute class would
work with every implementation of IPrinciple, and not just with the
WindowsPrincipal & GenericPrincipal, is that correct?

Am i missing something obvious here? Would especially be grateful for links
to docs exploring .NET security with custom implementations of different
security related classes...

Thanks in advance, all help welcome...

Baileys.

15 Mar 2005 3:04 PM

Nicole Calinoiu

PrincipalPermission should work against all implementations of IPrincipal,
but it evaluates solely against the thread principal, so you'll absolutely
need to use Thread.CurrentPrincipal in addition to (or instead of) the
HttpContext user. In order to pass a PrincipalPermission demand, the thread
principal will need to match the specified user name and/or role membership,
and it will also need to be authenticated (as specified by the
IPrincipal.Identity.IsAuthenticated property). I'm guessing that the
problem probably lies with a failure to set the IsAuthenticated property for
the principal.

HTH,
Nicole

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"Baileys" <Bail***@discussions.microsoft.com> wrote in message
news:333E0CA6-5E0A-4D87-8CE3-2EEA96129D00@microsoft.com...
> Hi,
>
> I'm having trouble getting declarative checks (using
> PrinciplePermissionAttribute) to work with my custom IPrincipal
> implementation in a web scenario.
>
> I created a custom principal class (MyPrincipal), implementing the
> IPrincipal interface
> I added code to the global.asax Application_AuthenticateRequest handler to
> construct an instance of MyPrincipal, and assign this instance to
> Context.User (also tried assigning the instance to both Context.User and
> Thread.CurrentPrincipal).
> I've got a class (MyClass) defined as follows:
>
> public class MyClass
> {
> [PrincipalPermission(SecurityAction.Demand, Role="Admin")]
> public static void MyMethod()
> {
>    // do stuff
> }
> }
>
> I have got a web page containing the following code in Page_Load:
>
> bool test = Thread.CurrentPrincipal.IsInRole("Admin"); // 1. works
> (test=true)
> bool test2 = Context.User.IsInRole("Admin");               // 2. works
> (test2=true)
>
> PrincipalPermission p = new PrincipalPermission(null, "Admin");
> p.Demand();                                                            //
> 3
> .Fails
>
> MyClass.MyMethod()                                                // 4.
> Fails
>
> The last 2 methods (using PrincipalPermission.Demand and calling the
> MyMethod) fail with a security exception ( Exception Details:
> System.Security.SecurityException: Request for principal permission
> failed.).
>
> I was under the impression that PrincipalPermissionAttribute class would
> work with every implementation of IPrinciple, and not just with the
> WindowsPrincipal & GenericPrincipal, is that correct?
>
> Am i missing something obvious here? Would especially be grateful for
> links
> to docs exploring .NET security with custom implementations of different
> security related classes...
>
> Thanks in advance, all help welcome...
>
> Baileys.
>

15 Mar 2005 9:32 PM

Dominick Baier [DevelopMentor]

Hello Baileys,

only apply your IPrincipal impl to Context.User -

there is a undocumented event "DefaultAuthentication" that fires directly
after AuthenticateRequest that copies Context.User to Thread.CurrentPrincipal.

---------------------------------------
Dominick Baier - DevelopMentor
http://www.leastprivilege.com

Show quoteHide quote

> Hi,
>
> I'm having trouble getting declarative checks (using
> PrinciplePermissionAttribute) to work with my custom IPrincipal
> implementation in a web scenario.
>
> I created a custom principal class (MyPrincipal), implementing the
> IPrincipal interface
> I added code to the global.asax Application_AuthenticateRequest
> handler to
> construct an instance of MyPrincipal, and assign this instance to
> Context.User (also tried assigning the instance to both Context.User
> and
> Thread.CurrentPrincipal).
> I've got a class (MyClass) defined as follows:
> public class MyClass
> {
> [PrincipalPermission(SecurityAction.Demand, Role="Admin")]
> public static void MyMethod()
> {
> // do stuff
> }
> }
> I have got a web page containing the following code in Page_Load:
>
> bool test = Thread.CurrentPrincipal.IsInRole("Admin"); // 1. works
> (test=true) bool test2 = Context.User.IsInRole("Admin");
> // 2. works (test2=true)
>
> PrincipalPermission p = new PrincipalPermission(null, "Admin");
> p.Demand();
> // 3 .Fails
>
> MyClass.MyMethod() //
> 4. Fails
>
> The last 2 methods (using PrincipalPermission.Demand and calling the
> MyMethod) fail with a security exception ( Exception Details:
> System.Security.SecurityException: Request for principal permission
> failed.).
>
> I was under the impression that PrincipalPermissionAttribute class
> would work with every implementation of IPrinciple, and not just with
> the WindowsPrincipal & GenericPrincipal, is that correct?
>
> Am i missing something obvious here? Would especially be grateful for
> links to docs exploring .NET security with custom implementations of
> different security related classes...
>
> Thanks in advance, all help welcome...
>
> Baileys.
>

16 Mar 2005 6:51 AM

Baileys

Thanks Nicole and Dominick,

@Nicole, you guessed right, my implementation of IsAuthenticated was buggy,
fixed that and everything works as expected...

@Dominick, do you happen to have a link to some documentation on that
undocumented behavior?

rgds,
Baileys

16 Mar 2005 12:46 PM

Nicole Calinoiu

For documentation of the copying of the context user to the thread
principal, search for the first occurrence of the word "thread" at
http://msdn.microsoft.com/library/en-us/dnnetsec/html/SecNetAP04.asp.

Show quoteHide quote

"Baileys" <Bail***@discussions.microsoft.com> wrote in message
news:AF107FF6-A8D1-481B-AC68-FAD1F18A1A00@microsoft.com...
> Thanks Nicole and Dominick,
>
> @Nicole, you guessed right, my implementation of IsAuthenticated was
> buggy,
> fixed that and everything works as expected...
>
> @Dominick, do you happen to have a link to some documentation on that
> undocumented behavior?
>
> rgds,
> Baileys

16 Mar 2005 12:47 PM

Nicole Calinoiu

It's possible to run into trouble if one relies on this mechanism alone
since code that demands PrincipalPermission can be executed before
HttpApplication.SetPrincipalOnThread is run.

Show quoteHide quote

"Dominick Baier [DevelopMentor]" <dbaier@pleasepleasenospamdevelop.com>
wrote in message news:138135632465227438566637@news.microsoft.com...
> Hello Baileys,
>
> only apply your IPrincipal impl to Context.User -
> there is a undocumented event "DefaultAuthentication" that fires directly
> after AuthenticateRequest that copies Context.User to
> Thread.CurrentPrincipal.
>
>
>
> ---------------------------------------
> Dominick Baier - DevelopMentor
> http://www.leastprivilege.com
>
>> Hi,
>>
>> I'm having trouble getting declarative checks (using
>> PrinciplePermissionAttribute) to work with my custom IPrincipal
>> implementation in a web scenario.
>>
>> I created a custom principal class (MyPrincipal), implementing the
>> IPrincipal interface
>> I added code to the global.asax Application_AuthenticateRequest
>> handler to
>> construct an instance of MyPrincipal, and assign this instance to
>> Context.User (also tried assigning the instance to both Context.User
>> and
>> Thread.CurrentPrincipal).
>> I've got a class (MyClass) defined as follows:
>> public class MyClass
>> {
>> [PrincipalPermission(SecurityAction.Demand, Role="Admin")]
>> public static void MyMethod()
>> {
>> // do stuff
>> }
>> }
>> I have got a web page containing the following code in Page_Load:
>>
>> bool test = Thread.CurrentPrincipal.IsInRole("Admin"); // 1. works
>> (test=true) bool test2 = Context.User.IsInRole("Admin");
>> // 2. works (test2=true)
>>
>> PrincipalPermission p = new PrincipalPermission(null, "Admin");
>> p.Demand();
>> // 3 .Fails
>>
>> MyClass.MyMethod() //
>> 4. Fails
>>
>> The last 2 methods (using PrincipalPermission.Demand and calling the
>> MyMethod) fail with a security exception ( Exception Details:
>> System.Security.SecurityException: Request for principal permission
>> failed.).
>>
>> I was under the impression that PrincipalPermissionAttribute class
>> would work with every implementation of IPrinciple, and not just with
>> the WindowsPrincipal & GenericPrincipal, is that correct?
>>
>> Am i missing something obvious here? Would especially be grateful for
>> links to docs exploring .NET security with custom implementations of
>> different security related classes...
>>
>> Thanks in advance, all help welcome...
>>
>> Baileys.
>>
>
>
>