Call this method to add data to the hash.
Pointer to a buffer containing the data to be added to the hash.
Number of bytes of data to be added. Must be 0 if the CRYPT_USERDATA flag is set.
Set the CRYPT_USERDATA flag to specify that the cryptographic service provider prompts the user to input data directly. In this case, the data is added to the hash, and the application is not allowed to access the data. This flag can be set to allow the user to enter a PIN into the system.