Troubleshooting Local Communication in Software

Painting QR Code ISO/IEC18004 in Software Troubleshooting Local Communication
Troubleshooting Local Communication
Draw QR-Code In Visual C#.NET
Using Barcode printer for .NET Control to generate, create QR Code image in Visual Studio .NET applications.
At this moment, it is very clear why the server thread needs so much time to add a few numbers; one of the sample writers intentionally left a kernel32!Sleep function call for debugging purposes
QR Code JIS X 0510 Maker In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create QR Code 2d barcode image in ASP.NET applications.
Impersonating Local DCOM and LRPC Calls
QR-Code Creation In .NET
Using Barcode printer for .NET framework Control to generate, create QR Code image in .NET framework applications.
Impersonation is a fundamental concept used in the current versions of the Windows operating system It enables a specific thread to execute all the operations under a security context different from the process owning the thread The impersonation can be enabled or disabled on demand by setting or resetting the impersonation token on the thread But what happens from a security perspective when a client thread makes a call into a server using the LPC protocol The client can specify what impersonation token must be presented to the server, and the kernel stores that information on the server thread When the server impersonates the client using the RPC function rpcrt4!RpcImpersonateClient or the DCOM function ole32!CoImpersonateClient, the impersonation is performed by another LPC function called ntdll!NtImpersonateClientOfPort This function uses the impersonation information stored on the thread by the Windows kernel at the moment the message was transferred to the server From the user mode debugger, the impersonation information can be checked only after the server makes a call into one of the impersonation functions by checking the token currently set on the thread, the method often used in 7, Security From the kernel mode debugger, this is much easier; the information is always present in the server thread, as a pointer to _PS_IMPERSONATION_INFORMATION stored in the ImpersonationInfo member of the thread structure, _ETHREAD Along with the impersonation token, there are instructions on how to impersonate the client In the case shown in Listing 812, any impersonation results in a token at identify level Listing 812
QR Code ISO/IEC18004 Drawer In Visual Basic .NET
Using Barcode creator for .NET framework Control to generate, create QR Code image in Visual Studio .NET applications.
Reading ImpersonationInfo stored on the server thread
Making Barcode In Java
Using Barcode creator for Java Control to generate, create bar code image in Java applications.
8 INTERPROCESS COMMUNICATION
Bar Code Reader In .NET Framework
Using Barcode recognizer for .NET Control to read, scan read, scan image in .NET framework applications.
kd> dt _ETHREAD ffab1020 ImpersonationInfo +0x20c ImpersonationInfo : 0xe1269038 _PS_IMPERSONATION_INFORMATION kd> dt 0xe1269038 _PS_IMPERSONATION_INFORMATION +0x000 Token : 0xe1acba08 +0x004 CopyOnOpen : 0 +0x005 EffectiveOnly : 0 +0x008 ImpersonationLevel : 1 ( SecurityIdentification )
Data Matrix Printer In Java
Using Barcode creator for Java Control to generate, create Data Matrix 2d barcode image in Java applications.
8
Make Barcode In Java
Using Barcode generation for Java Control to generate, create barcode image in Java applications.
Interprocess Communication
UCC.EAN - 128 Generation In Java
Using Barcode maker for Java Control to generate, create UCC.EAN - 128 image in Java applications.
The information in this section helps when debugging a simple scenario using local LRPC or DCOM calls More complex scenarios, such as DCOM activation, are, from the perspective of debugging, just a combination of calls and can be handled by following the same simple steps illustrated previously
EAN 13 Generation In .NET Framework
Using Barcode drawer for VS .NET Control to generate, create EAN / UCC - 13 image in .NET framework applications.
Troubleshooting Remote Communication
Bar Code Reader In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
MS RPC extends the RPC implementation by providing platform-specific security models and adding support for LPC communication Although the local communication has excellent debugging support, the remote communication is lacking those facilities In this section, we explore the option available to developers to compensate for the debugging support missing in this area One option is to capture all the knowledge required to debug the main scenarios into a smart extension capable of interpreting all internal structures and the relationship between different structures The extension can show this information in an easy-to-understand form and can automate the whole process of detecting the call path Unfortunately, no such extension is currently available To answer those challenges, the RPC team introduced a special method of debugging the communication between the client and the server, by using additional tracing information called RPC Troubleshooting State Information This method is described in the next section
Paint European Article Number 13 In Java
Using Barcode encoder for Java Control to generate, create EAN / UCC - 13 image in Java applications.
Using RPC Troubleshooting State Information
Code39 Drawer In C#.NET
Using Barcode generation for Visual Studio .NET Control to generate, create Code 39 Full ASCII image in VS .NET applications.
Since this is the only method accessible today, we focus on it for the remainder of this section Because the information is stored in cells of information used only for debugging purposes, the method using them is also called RPC cell debugging, or cell debugging The first part of this section describes how to control the RPC runtime behavior regarding the maintenance of the state information; the second part details where this information is stored and how it can be accessed; and the third part describes the tools available to filter and display it The last part uses those tools to solve a real-case scenario Please note that the cell debugging is available starting with Windows XP and Windows 2003
DataMatrix Reader In .NET Framework
Using Barcode scanner for .NET Control to read, scan read, scan image in .NET applications.
Drawing UPC Code In .NET
Using Barcode printer for .NET Control to generate, create UPC A image in .NET applications.
Printing Barcode In Java
Using Barcode printer for Java Control to generate, create barcode image in Java applications.
Universal Product Code Version A Recognizer In VS .NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.