An application that calls Cryptography API (CryptoAPI) functions may stop responding on a Windows XP-based computer

On a Microsoft Windows XP-based computer, an application that calls Cryptography API (CryptoAPI) functions may stop responding.

This problem occurs because of a defect in the Crypt32.dll file. In some cases, a LoaderLock issue may occur in CrytoAPI because of this defect. Therefore, this problem occurs.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply the hotfix, one of the following service packs must be installed on the computer:

• Microsoft Windows XP Service Pack 1 (SP1)
• Microsoft Windows XP Service Pack 2 (SP2)

Restart requirement

You have to restart your computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfix.

Registry information

You do not have to make any changes to the registry to use the hotfixes in this package.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows XP with SP1, x86-based versions

Windows XP with SP2, x86-based versions

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Software developers use CryptoAPI to add authentication, encoding, and encryption to Windows-based applications. For more information about CryptoAPI, visit the following Microsoft Web site:For more information about LoaderLock, visit the following Microsoft Web site: For more information, click the following article number to view the article in the Microsoft Knowledge Base: