Extract an encrypted private key from a PKCS-12 PKCS8ShroudedKeyBag, saving the output directly as a new file.
public static int GetPrivateKeyFromPFX( string outputFile, string pfxFile )
Public Shared Function GetPrivateKeyFromPFX ( _ outputFile As String, _ pfxFile As String _ ) As Integer
VB6/C equivalent: RSA_GetPrivateKeyFromPFX