Support Windows serialized keystores (SST files)

SUMMARY

Allow keystores to be loaded from files (SSTs [1]) on Windows

PROBLEM

In some applications it is preferred to load a certificate from a file. On Windows, certificates can be serialized into SST files; currently there is no support in the JDK/libraries for loading SST files.

PROPOSED SOLUTION

With a small change to the SunMSCAPI keystore provider, the additional of a new KeyStore name and no code changes to the library APIs, SST keystores would be loaded as in the following example:

KeyStore keyStore = KeyStore.getInstance("Windows-SST");
try (FileInputStream fis = new FileInputStream("mykeystore.sst")) {
   keyStore.load(fis, null);
}

[1] https://learn.microsoft.com/en-us/powershell/module/pki/export-certificate?view=windowsserver2022-ps