Structure lock in HSSFWorkbook possible?

Question

In the POI XSSFWorkbook, the methods lockStructure and lockWindows exist with which an Excel Workbook can be protected. (Function in excel menue under "Review->Protect Workbook...")
The function of these methods is analogous to the Workbook.protect method in Excel: https://learn.microsoft.com/en-us/office/vba/api/excel.workbook.protect

Is there any way to enable this protection in a HSSFWorkbook?

I have already tried the writeProtectWorkbook method from HSSFWorkbook, but it does not do the same as the methods in the XSSFWorkbook. The method writeProtectWorkbook sets an open password.

Probably I have to modify the "worksheet protection block" which is described in section 5.82 here on page 200: http://www.openoffice.org/sc/excelfileformat.pdf

Does anyone know how I can get this block with POI?
I use poi:5.0.0.

Answer 1

I found out myself how to enable Workbook Protection. In the InternalWorkbook there is a list of records. These contain the record types ProtectRecord, WindowProtectRecord and PasswordRecord. With these you can set the Workbook Protection:

List<Record> records = ((HSSFWorkbook) wb).getInternalWorkbook().getRecords();
for (Record record : records) {
    if (record instanceof ProtectRecord) {
        ((ProtectRecord) record).setProtect(true);
    } else if (record instanceof WindowProtectRecord) {
        ((WindowProtectRecord) record).setProtect(true);
    } else if (record instanceof PasswordRecord) {
        ((PasswordRecord) record).setPassword((short) CryptoFunctions.createXorVerifier1("password"));
    }
}