Keepassxc: Key derivation transformation seed stays the same on every save.

[mstarke]

Expected Behaviour

• the key derivation should use a random seed every time the key is used for saving

Current Behaviour

• the seed is created (or loaded) only once and then reused every time when saving the database iff no key change happened

Possible Solution

• generate a random transformation seed every time the database is stored

Debug Info

KeePassXC - 2.21
Revision: 2bce9c8add07226e9a05e9e0fd0e5e66b236d5b6

Operating system: macOS 10.12
CPU architecture: x86

[phoerious]

The master seed and encryption IV are regenerated every time the database is saved: https://github.com/keepassxreboot/keepassxc/blob/3e84c0a91a5281240d9e5db814a512c458957520/src/format/KeePass2Writer.cpp#L48
The transform seed, however, is not. There is no real incentive behind this other than that it was carried over from KeePassX and we never touched that part of the code. I don't know if the original author did it as a (questionable) performance optimization or simply forgot to regenerate it. I do agree that this should be changed.

[rockihack]

@droidmonkey I fixed the issue and can send a pull-request if you want.

https://github.com/rockihack/keepassx/commit/1b0e1c2dfba2adb579ddcf5e1afea66d4afdc56e

[droidmonkey]

yes please do. target for 2.2.2