I want to sign file with the SunMSCAPI provider. As public key and signatures needs to be imported using MS Crypto API.
Generally generating signatures
If you work with MSCAPI, it is assumed that you've added your key to the Microsoft Certificate store. You can check if the key is present by going to "Internet Properties" > "Content" > "Certificates" which gives you a list of certificates that are available. If your certificate isn't there, you can't use it. If it's there, you need this code:
SunMSCAPI providerMSCAPI = new SunMSCAPI();
Security.addProvider(providerMSCAPI);
KeyStore ks = KeyStore.getInstance("Windows-MY");
ks.load(null, null);
From there on, the code is pretty standard. Please consult my book on digital signatures for more info (the book is free).
IMPORTANT ADDITION: I forgot to mention that SunMSCAPI isn't present in the 64-bit version of Java 6 (I don't know about Java 7). You can fix this by installing the 32-bit version.