Microsoft Open Specifications Support Team Blog

In one of my previous blog( http://blogs.msdn.com/b/openspecification/archive/2010/11/17/encryption-type-selection-in-kerberos-exchanges.aspx ) , I have talked about how the encryption types of the various encrypted parts of the Kerberos exchanges are...

Background The performance of remote file operations, such as read/write, using SMB protocol can be affected by the size of buffers allocated by servers and clients. The buffer size determines the number of round trips needed to send a fixed amount...

In this blog, I would like to help the reader understand the rules that govern unique attributes in Active Directory (AD) along with the Open Protocols documentation set. I provide examples for user naming attributes. I also clarify common misunderstandings...

Opportunistic locks ,or oplock is a client caching mechanism that allows SMB/SMB2 clients to dynamically decide the client-side buffering strategy so the network traffic can be minimized. For example, a client can buffer data for writing locally to reduce...

This blog post focuses on understanding Microsoft Kerberos PAC validation. It discusses the topic from inter-operability perspective with Windows operating systems. A SMB session establishment scenario is used to illustrate how PAC validation works. ...

In my previous two blog entries, I’ve focused on becoming familiar with the Compound File Binary Format which we discovered was similar to a FAT file system within a file.  With that exercise behind us we’re ready to step up a level in the ecology...

The types of encryption used in various Kerberos exchanges are very important and sometime confusing aspects of the Kerberos implementation. We not only need to understand the Kerberos RFC (RFC 4120, RFC 3961 etc) that specifies generally how the encryption...

Introduction In order to be concise with this article, I need to assume that the reader is familiar with Kerberos and Active Directory. If not, then I can quickly think of two scenarios: 1) Your favorite search engine ( Bing in my case) took...

Although the march of progress steadily tramples the old tried and true in favor of enlightened file formats designed for the new era of the web, some of us take joy in digging deeper into bits and bytes of binary file formats. I’m one of those...

Windows remote management is a technology that can be used to manage windows servers. By installing the download ws-management onto a windows 2003 r2 server, this server can act as an event collector. This document describes the steps taken to enable...

… and the discussion goes like that for a couple hours. Have you been in that situation before? If the answer is no… then you probably have something better to do than reading this blog. May I suggest Dilbert ? I’m a longtime fan. If the answer...

Suppose your application requirement is to programmatically create password “protected” Office Open XML (OOXML) documents. Or, perhaps the requirement is to programmatically convert a batch of unprotected OOXML documents to password protected ones. The...

Shakespeare knew nothing about Kerberos V5… Nothing! But, I still like him! And that, despite the fact that he had the audacity to paraphrase me in his play “Hamlet”. Of course no one believes me! I must admit it would be much...

Hi y’all, Sebastian from Texas here! I’ve been at the File Sharing Plugfest last week. This time around I’ve had the chance to give a presentation on how we use the different sets of tools that we have at hand (both internal and...

This blog talks about secure dialect negotiation, one of the new SMB3 security enhancements in Windows Server 2012. Secure dialect negotiation is introduced in SMB3 to protect against man-in-the-middle attempt to downgrade dialect negotiation. The...

One design goal for the SMB 2.1 protocol implementation on Windows 2008 R2 and Windows 7 was to achieve better performance for 10 Gigabit Ethernet (very high speed / low latency networks). This has been achieved with a new feature called ‘Large MTU’,...

Hitchhiker’s Guide to Debugging RDP protocols: Part 2 NOTE: Questions and comments are welcome. However, please DO NOT post a comment using the comment tool at the end of this post. Instead, post a new thread in the Open Specifications Forum...

In my last blog , I discussed the general format for an email message saved to disk by Outlook or a compatible email client. The .msg file format explained in MS-OXMSG , is a Compound File with storages and streams containing properties and data describing...

Unless otherwise specified, references in this document are from the Windows Software Development Toolkit (SDK) (v7.0) and the Windows Driver Kit (WDK) (v7600.16385.0), which defines at least 46 mask sets and 500+ bit flag value declarations. The document...

RC4 CryptoAPI Encryption Password Verification -=- Dominic Salemno -=- Information security is important in this day and age. The most important core asset of any particular company is their information. Hence, the essential need for cryptography...

I am writing this blog in response to a need I felt when I was new to authentication in Windows. The blog does not intend to reinvent the wheel, instead to help someone new to Windows authentication to get started and find the resources one needs to understand...

In this blog I’d like to cover every aspect of parsing Office binary documents, and do it in less than a thousand words. But, what follows is more realistic, thus more narrow in focus. Specifically, I’ll examine the PowerPoint binary format from the point...

ActiveSync III Dominic Salemno Introduction In the last segment I went over some basic details regarding the ActiveSync protocol. In this latest in a series, I want to touch on the ability to Sync a folder. Initialization Before the client...

Hitchhiker’s Guide to Debugging RDP protocols: Part 1 [MS-RDPEUSB] NOTE: Questions and comments are welcome. However, please DO NOT post a comment using the comment tool at the end of this post. Instead, post a new thread in the Open Specifications...

Encryption Negotiation in RDP connection The RDP connections between clients and servers are normally encrypted for better security. When we observe the network traffic to troubleshoot the RDP related problems, we may notice that the traffic between...