asp.net + unmanaged dll security issues

[Priya]

Hi,
I'm developing an ASP.NET application. I imported a C++ dll into the C# code.
When I tried to access a function in that dll, application threw an exception
"System.Runtime.InteropServices.SEHException:Exter nal component has thrown
an exception". I debugged the unmanaged C++ code & found that the code that
generated this exception is

CDaoDatabase db;
db.open("C:\\VM.mdb") // this is the code that generated exception

I tried using try catch blocks
but the control does'nt come to catch block
How do i determine the exception?
The same dll function works fine if the dll is impoted in a Windows
application.
Is there any security issues in Web application?

Thanks in advance
Priya

[bruce barker]

to get better error reporting, the c++ nneds to trap errors, and supply an
error reporting function. in your case the error is probably permission, as
asp.net does not have access rights to @"c:\" by default.
-- bruce (sqlwork.com)
"Priya" <Pr***@discussions.microsoft.com> wrote in message
news:64**********************************@microsof t.com...

Hi,
I'm developing an ASP.NET application. I imported a C++ dll into the C# code. When I tried to access a function in that dll, application threw an exception "System.Runtime.InteropServices.SEHException:Exter nal component has thrown
an exception". I debugged the unmanaged C++ code & found that the code that generated this exception is

CDaoDatabase db;
db.open("C:\\VM.mdb") // this is the code that generated exception

I tried using try catch blocks
but the control does'nt come to catch block
How do i determine the exception?
The same dll function works fine if the dll is impoted in a Windows
application.
Is there any security issues in Web application?

Thanks in advance
Priya

[Priya]

I tried setting the write permission to the database file(I:\data\VM.mdb) ,
the folder containing the database file , to the aspx file and the folder
containing it in ASPNET account , Everyone , IUSR_Machinename account.

I added <identity impersonate ="true"> in web.config file.
The ASP.NET state service has default logon as Local System Account.

I modified username= "machine " to username = "system" in machine.config
(C:\Winnt\Microsoft.Net\Config\machine.config)
still it does'nt work.

What is the mistake i'd done???
Thanks
Priya

"bruce barker" wrote:

to get better error reporting, the c++ nneds to trap errors, and supply an
error reporting function. in your case the error is probably permission, as
asp.net does not have access rights to @"c:\" by default.
-- bruce (sqlwork.com)
"Priya" <Pr***@discussions.microsoft.com> wrote in message
news:64**********************************@microsof t.com...

Hi,
I'm developing an ASP.NET application. I imported a C++ dll into the C#

code.

When I tried to access a function in that dll, application threw an

exception

"System.Runtime.InteropServices.SEHException:Exter nal component has thrown
an exception". I debugged the unmanaged C++ code & found that the code

that

generated this exception is

CDaoDatabase db;
db.open("C:\\VM.mdb") // this is the code that generated exception

I tried using try catch blocks
but the control does'nt come to catch block
How do i determine the exception?
The same dll function works fine if the dll is impoted in a Windows
application.
Is there any security issues in Web application?

Thanks in advance
Priya