[tikipiya]

Fixes #13974

Summary

• Keep the KDBX version from the file header when setKdf() runs during open.
• Add testMinorVersionMismatchAfterSetKdf to prevent regressions.

Testing strategy

• ctest -R testkdbx4 -V (includes new test; all 41 subtests passed in Docker Ubuntu 24.04)

Type of change

• Bug fix (non-breaking change that fixes an issue)

[Grinv]

This breaks converting a database to KDBX 3. Saving the encryption settings goes through changeKdf() to setKdf(), where ignoreCurrent = false keeps the version at 4.0. KeePass2Writer::writeDatabase() then sees AES-KDBX3 with version 4 and replaces the KDF with AES-KDBX4.

I tested it on Qt 6.4.2 with a small QTest that drives the settings widget (condensed):

// db was read from a KDBX 4 file
DatabaseSettingsWidgetEncryption widget;
widget.loadSettings(db);
widget.initialize();
widget.findChild<QTabWidget*>("encryptionSettingsTabWidget")->setCurrentWidget(widget.findChild<QWidget*>("advancedTab"));
widget.findChild<QComboBox*>("compatibilitySelection")->setCurrentIndex(1); // "KDBX 3"
widget.findChild<QSpinBox*>("transformRoundsSpinBox")->setValue(100000);
QVERIFY(widget.saveSettings());
// write db with KeePass2Writer, read it back with KeePass2Reader
QCOMPARE(reader.version(), KeePass2::FILE_VERSION_3_1);

	File version	KDF after reopening
develop	3.1	AES-KDF (KDBX 3)
this PR	4.0	AES-KDF (KDBX 4)
this PR + the line below	3.1	AES-KDF (KDBX 3)

Adding this after setKdf(kdf) in changeKdf() fixes it. This PR's new test, testkdbx3, testkdbx4 and testdatabase still pass with it:

setFormatVersion(KeePass2Writer::kdbxVersionRequired(this, true));

[tikipiya]

Understood. I will make the corrections.

[tikipiya]

I have completed the revisions requested by Grinv. Please take a look.

[Grinv]

Thanks for the quick fix! With d74f768 the database saves as 3.1 with AES-KDF (KDBX 3). If you want a regression test for this bug, you can add the one below. It fails without the new line in changeKdf() and passes with it (Qt 6.4.2). It also needs void testChangeKdfDowngradesToKdbx3(); in tests/TestKdbx4.h.

void TestKdbx4Format::testChangeKdfDowngradesToKdbx3()
{
    auto key = QSharedPointer<CompositeKey>::create();
    key->addKey(QSharedPointer<PasswordKey>::create("test"));

    Database db;
    db.setKey(key, true, true);
    db.changeKdf(fastKdf(KeePass2::uuidToKdf(KeePass2::KDF_ARGON2D)));
    QCOMPARE(db.formatVersion(), KeePass2::FILE_VERSION_4);

    db.changeKdf(fastKdf(KeePass2::uuidToKdf(KeePass2::KDF_AES_KDBX3)));
    QCOMPARE(db.formatVersion(), KeePass2::FILE_VERSION_3_1);

    QBuffer buffer;
    buffer.open(QBuffer::ReadWrite);
    KeePass2Writer writer;
    QVERIFY(writer.writeDatabase(&buffer, &db));

    buffer.seek(0);
    KeePass2Reader reader;
    Database reopened;
    QVERIFY(reader.readDatabase(&buffer, key, &reopened));
    QCOMPARE(reader.version(), KeePass2::FILE_VERSION_3_1);
    QCOMPARE(reopened.kdf()->uuid(), KeePass2::KDF_AES_KDBX3);
}

[droidmonkey]

Let's add the test, its a good one to be in the inventory

[tikipiya]

May I ask if this is a task that I should handle?

[Grinv]

May I ask if this is a task that I should handle?

Yes, please add it to this PR :)

[tikipiya]

Understood. I would be glad to take this on. Since this is my first PR, I am unfamiliar with many things, so I am very grateful to be working with such a kind and supportive team on this project.

[tikipiya]

I believe it is complete.

[tikipiya]

#13982
I accidentally pushed the changes from this PR to this branch.

[tikipiya]

Would it be acceptable to close the other PR (#13982) and include the grammar and typo fixes in this PR as additional changes?

[phoerious]

Since it's just one or two string changes, you can add them here. But please remove all the other language files from the commit. Only commit the keepassxc_en.ts file that is generated when you run ./release-tool i18n lupdate.

[tikipiya]

Please check this.
(It seems that when I made a commit from the Cursor terminal, Cursor tagged along... I mind it at least, but please don't mind it.)