How do I programmatically install a certificate to the windows personal certificate store using Java?

Question

In the windows personal certificate store, I am trying to programmatically install a certificate with the private key(using method setKeyEntry) using Java. But I get an exception when I do that.

Caused by: java.lang.UnsupportedOperationException: Cannot assign the key to the given alias.
    at jdk.crypto.mscapi/sun.security.mscapi.CKeyStore.engineSetKeyEntry(CKeyStore.java:405)
    at jdk.crypto.mscapi/sun.security.mscapi.CKeyStore$MY.engineSetKeyEntry(CKeyStore.java:57)

Code snippet:

    KeyStore userCertStore = KeyStore.getInstance(getValue(CERTIFICATE_STORE_TYPE));
    userCertStore.load(null,null);
    for (iaik.x509.X509Certificate cert : user.getUserCertificates()) {
        userCertStore.setCertificateEntry(cert.getSubjectDN().toString(), cert);
        userCertStore.setKeyEntry(cert.getSubjectDN().toString(),user.getUserPrivateKey(cert),new 
        SecureStringBuffer(new StringBuffer(password)).toCharArray(),user.getUserCertificates());
    }

Answer 1

The certificates are already set during setKeyEntry - do not store the certificate using setCertificateEntry.

setCertificateEntry is used to set trusted certificates (of the other party), the setKeyEntry is used to store private keys and the full certificate chain belonging to that private key.

So when you set the private key the alias is already taken by a "trusted certificate".