public static extern bool CryptAcquireContext(
     ref IntPtr hProv,
     string containerName,
     string providerName,
     int providerType,
     CryptContextFlags flags
     );
 public static extern bool CryptAcquireContext(
     ref IntPtr hProv,
     string containerName,
     string providerName,
     int providerType,
     CryptContextFlags flags
     );