Externally opened attachments are now lifecycle-managed properly.
The temporary files are created with stricter permissions and entirely
random names (except for the file extension) to prevent meta data leakage.
When the database is closed, the files are overwritten with random
data and are also more reliably deleted than before.
Changes to the temporary files are monitored and the user is asked
if they want to save the changes back to the database (fixes#3130).
KeePassXC does not keep a lock on any of the temporary files, resolving
long-standing issues with applications such as Adobe Acrobat on Windows
(fixes#5950, fixes#5839).
Internally, attachments are copied less. The EntryAttachmentsWidget
now only references EntryAttachments instead of owning a separate copy
(which used to not be cleared properly under certain circumstances).
The Database, DatabaseWidget, and DatabaseTabWidget classes share many responsibilities in inconsistent ways resulting in impenetrable and unmaintainable code and a diverse set of bugs and architecture restrictions. This patch reworks the architecture, responsibilities of, and dependencies between these classes.
The core changes are:
* Move loading and saving logic from widgets into the Database class
* Get rid of the DatabaseManagerStruct and move all the information contained in it into the Database
* Let database objects keep track of modifications and dirty/clean state instead of handing this to external widgets
* Move GUI interactions for loading and saving from the DatabaseTabWidget into the DatabaseWidget (resolves#2494 as a side-effect)
* Heavily clean up DatabaseTabWidget and degrade it to a slightly glorified QTabWidget
* Use QSharedPointers for all Database objects
* Remove the modifiedImmediate signal and replace it with a markAsModified() method
* Implement proper tabName() method instead of reading back titles from GUI widgets (resolves#1389 and its duplicates #2146#855)
* Fix unwanted AES-KDF downgrade if database uses Argon2 and has CustomData
* Improve code
This patch is also the first major step towards solving issues #476 and #2322.
Closes#6
Attachments are now stored in a pool under Metadata instead of in entries.
The protected flag of attachments isn't supported anymore.
New metadata attributes: color, historyMaxItems and historyMaxSize.
Dropped metadata attribute: autoEnableVisualHiding.
