The Microsoft Excel File Format - OpenOffice.org

4 Worksheet/Workbook Stream
4.18 Worksheet/Workbook Protection
An Excel document may contain different types of protection.
Definition: Worksheet/workbook protection
Worksheet/workbook protection protects specific contents of the worksheet or workbook, for instance window
settings, cell contents, or objects.
Definition: File protection
File protection protects the file itself, either sets to read-only, or restricts read and write access. File protection
does not care about the contents of the document. This type of protection is described in the next chapter
(➜4.19).
Not all records regarding protection must occur in the stream. If a record is omitted, the corresponding item is not active
(for instance: omitting the OBJECTPROTECT record leaves objects unprotected). For the position of the mentioned
records in the substreams see ➜4.2.
4.18.1 Single Worksheet Protection (BIFF2-BIFF4)
Definition: Worksheet Protection Block
Several records in the Worksheet Protection Block determine the protected items in the sheet.
PROTECT protects the cell contents, WINDOWPROTECT protects the window settings, and OBJECTPROTECT
protects the embedded objects. The PASSWORD record contains the hash value of the password (➜4.18.4) used to
protect the sheet. All the mentioned records occur always, if the file was written by Excel, but may be omitted.
If a protection password is set in the PASSWORD record, the read/write file protection (➜4.19) will be enabled, which
causes encryption of the file (➜4.19.1) in every case. If this protection is not enabled manually while saving the file, the
built-in password “VelvetSweatshop” is used, not the password set for worksheet protection.
Structure of the Worksheet Protection Block, BIFF2-BIFF4:
○ PROTECT Cell contents: 1 = protected (➜5.82)
○ WINDOWPROTECT Window settings: 1 = protected (➜5.111)
○ OBJECTPROTECT Embedded objects: 1 = protected (➜5.72)
○ PASSWORD Hash value of the password; 0 = No password (➜5.76)
4.18.2 Sheet Protection in a Workbook (BIFF5-BIFF8)
The PROTECT record in the Worksheet Protection Block indicates that the sheet is protected. There may follow a
SCENPROTECT record or/and an OBJECTPROTECT record. The optional PASSWORD record contains the hash
value of the password used to protect the sheet (➜4.18.4). In BIFF8, there may occur additional records following the
cell records in the Sheet Substream (➜4.2.5).
Sheet protection with password does not cause to switch on read/write file protection. Therefore the file will not be
encrypted.
Structure of the Worksheet Protection Block, BIFF5-BIFF8:
○ PROTECT Worksheet contents: 1 = protected (➜5.82)
○ OBJECTPROTECT Embedded objects: 1 = protected (➜5.72)
○ SCENPROTECT Scenarios: 1 = protected (➜5.91)
○ PASSWORD Hash value of the password; 0 = no password (➜5.76)
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