You create a key container on a machine for a specific user on the user’s profile. You log off the user and login with the administrator account and forcibly change the user’s password. Next time if you log on to the machine with the...

You may get a runtime error with your 64 bit managed Windows Media Encoder application while the 32 bit application runs perfect. This happens basically when your application tries to encode or more specifically transcode certain files that usually...

While updating your Windows 2000 box with latest security fixes you may get a situation where you may be stuck with the security fix MS10-013 asking you to update the latest DirectX. Basically this happens when you are doing a system update with the...

An understanding of SignedCms.CheckSignature(True) based on the code stated below. ' Create a ContentInfo object from the inner content obtained ' independently from encodedMessage. Dim contentInfo As New ContentInfo(innerContent...

You may want to use a Crypto API for Advanced Encryption Standard that is FIPS 140-2 complaint. While doing this using managed code you can come across the AesCryptoServiceProvider class that is FIPS complaint. I want to highlight some points before...

CertCloseStore is called with flag CERT_CLOSE_STORE_FORCE_FLAG. This flag forces CertCloseStore to free memory for all contexts associated with the store. This flag can be safely used only when the store is opened in a function and neither the store handle...

I have seen developers trying to call cryptographic functions/ API’s within DllMain and thereby creating a hang in their application that calls this DLL. The reason behind this is not the cryptographic API but this is a classical deadlock example. This...

This is a small blog post but I found it handy and useful to document. I created a test certificate with name “shmisra” and kept it in the “Personal” store in the users profile as shown below. I read this certificate and print its details using the code...

While trying to extract the public key from a certificate you may get an exception that says: 'System.Security.Cryptography.CryptographicException - The index value is not valid'. The exact error is CRYPT_E_INVALID_INDEX which means "The index value...

You may get a service timeout from your signed .NET service application while the OS does a revocation check to verify the certificate that signed the EXE. The reason behind this time out is because of a worker thread which is waiting for a response from...

DecryptMessage (Schannel) function returns SEC_E_INVALID_TOKEN, means the buffers are of the wrong type or no buffer of type SECBUFFER_DATA was found. In short the buffers are not set properly. A quick reference is the example at the link http://msdn...

A cryptographic service provider creates key containers for storing RSA public/private asymmetric key pairs. Key containers are stored in the user profiles unless you specify the machine key folder. Say you use RSACryptoServiceProvider class to create...

In Windows Vista and later there is a cool feature of making network shared files available offline and maintaining the synchronization through a newly added component called Sync Centre.  You may find more information about it here:  Explore...

ExpandEnvironmentStringsForUser() API does not expand the environment variable %USERNAME% on Windows 7 and Windows Server 2008 R2, if hToken value is obtained  only by using TOKEN_IMPERSONATE | TOKEN_QUERY flags for OpenProcessToken.  To expand...

Here is the scenario - You have a legacy application where you wish to load a DLL or module at a fixed or preferred base address.  Why would you need it?,  that is because in the EXE or DLL code you may make use of the absolute addresses and...

Symptom: ======= GetIPForwardTable return’s undocumented error ERROR_MORE_DATA where it should actually return ERROR_INSUFFICIENT_BUFFER in a Windows XP environment. Questions: ========= Is this an expected behavior? How we should handle the situation...

Introduction:     ARP is used to perform Duplicate Address Detection by sending an ARP request in which the Target Protocol Address is set to the IP address for which duplication is being detected. In other words, to detect whether other...

Working with Windows Service and Web Service together is nothing less than fun, especially when you are not an ASP.NET expert. Like many native developers I have my own challenges with words like managed, web service and web applications! I was debugging...

Recently, I was troubleshooting a problem for one of my customers. A named pipe created by a native C application was not accessible by web client. The actual product is a convention Windows application which does IPC through named pipes. Both server...

Your custom created 32 bit performance counters do not show counter information when generating logs using user defined Data collector Set with 32 bit “PerfMon” tool on 64 bit windows Server 2008 machine. However, you are able to get live performance...

There might be a need that an application need to send multiple files to the FAX server in one single call. While IFaxDocument::ConnectedSubmit Method allows to send a single file to FAX in one call, IFaxDocument2::ConnectedSubmit2 Method can be used...

When custom EAP authentication dll calls EapPeerInvokeInteractiveUI for wireless LAN 802.1x, a dialog box is displayed and a balloon is popped-up on Windows Vista machine. And the developer of the EAP authentication dll, needs to suppress dialog box and...

In the recent past, I have seen few question coming to me saying, “How do I write data on the CD/DVD disk programmatically?” . During my research, I came across the interfaces available on Windows for burning CD/DVD programmatically that I want to share...

Symptom: You may get Security Warning dialog while launching a process using fully qualified domain name path of the image. The warning dialog does not occur if image path is UNC path. For example, following piece of code will get the security warning...

If you are creating the cryptographic keys on the user's profile directory you may get a cryptographic exception saying: "CryptographicException: The system cannot find the file specified". The stack trace looks like: System.Security.Cryptography...