What kind of protection does File-save-password use?

[eastavin]

Good day. Have seen a number of questions and even articles on the web with a range of answers from… claiming libre office password protected files can have the password protection “removed by changing the contents of a config file” to these files are AES encrypted in the background and the user can do nothing to ever defeat the encryption other than enter the password… which cannot be truly correct either as there are various levels of AES encryption.

What is the truth? I see no explanation in the wiki of how file-save-password protects a file. Can someone point me to an official answer? I would like to understand before I entrust my data to the password.

This question does NOT refer to the save with GPG encryption option.

Best regards.

Edward

[ajlittoz]

Duplicate of 269506/what-kind-of-protection-does-file-save-password-use

Please delete this occurrence.

Perfect illustration of what I warned about in the other occurrence: during the time I wrote my comments, someone deleted the question without caution. If I had deleted this occurrence, your question would have disappeared without explanation.

To high-karma police users: NEVER delete a duplicate question on your own. At most, close one of the duplicates and leave a duplication warning message. Deletion is OP’s responsibility, not citizen vigilante’s.

[ajlittoz]

Duplicate of 269513/what-kind-of-protection-does-file-save-password-use

Please delete question 269513

[erAck]

have the password protection “removed by changing the contents of a config file”

That is a confusion with the cell and sheet protection and completely unrelated to save with encryption. The protection flags can indeed be removed, which is true for all unencrypted files in at least the file formats OOXML .xlsx and ODF .ods. See this FAQ. At least, because it’s also possible to remove it from binary .xls or others, just a bit more cumbersome.

files are AES encrypted in the background and the user can do nothing to ever defeat the encryption other than enter the password

That. Since 3.5 LibreOffice uses AES-256 for its native ODF files encryption, see Release Notes. The password is salted and PBKDF2 hashed with 100000 iterations to derive the key.

[eastavin]

So in summary what you are saying as all the pc’s here are using LO 6.0+ and 7.0+ the files in ODF mode are getting saved and encrypted withAES-256 anytime that option is selected. Thank you for the link to the release notes.