Registry Alias Files

SoftwareShield System Feature Guide > Alias Files > Registry Alias Files

## Registry Alias Files

You should already have read Alias Files and How to Create Alias Files.

Registry Alias Files are hidden registry keys which are cryptographically secure hashes of the of the Main License File. Whenever the main license file changes, all the alias files (including the Registry Alias Files) are immediately updated. The size of the hash (in bits) does not change with the size of the Main License File.

Registry Alias Files are entered under a class GUID in one of the following three root keys (which you specify):

1. HKEY_CLASSES_ROOT

2. HKEY_LOCAL_MACHINE

3. HKEY_CURRENT_USER

The actual path to the key depends on the root key you choose when defining the Registry Alias File. The paths are:

1. HKEY_CLASSES_ROOT uses key path: HKEY_CLASSES_ROOT\CLSID

2. HKEY_LOCAL_MACHINE uses key path: HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID

3. HKEY_CURRENT_USER uses key path: HKEY_CURRENT_USER\Software\Classes

The actual key that is created in this location has the GUID you specify for the Alias File as a name. A sub-key of that key named "InProcServer32" will contain a string value which is the string equivalent of the binary hash of the Main License File.

### Example:

> You specify a Registry Alias File with the root key being HKEY_CURRENT_USER. You give the Registry Alias File a GUID of {01B5DDC5-0800-4ED8-A59E-AE0730410893}. At run-time, when this Registry Alias File is written it will be written as:

> HKEY_CURRENT_USER\Software\Classes\{01B5DDC5-0800-4ED8-A59E-AE0730410893}

> It will have a value named:

> \InProcServer32

> The hash value written in that key may look like:

> 6EEFC3EB6D0F0DDB49CBD950E17E3363FFF704C15F2F3FE8EC3F05DC7F8D98D4

There are important security considerations when making decisions regarding how to use Registry Alias Files. Please be sure you have read the section on Windows Permissions and Security Considerations.

### More Information

For help in understanding how to create Alias Files in general, see How to Create Alias Files.

For help in actually creating Registry Alias File definitions for your license, see Creating Registry Alias Files in the SoftwareShield License Manager Reference.