Binary keyfiles of 64 bytes are not handled correctly

[oilarabla]

Describe the bug
When using a binary file of 64 bytes as a keyfile, databases generated by KeePass can't be opened using KeePassDX

To Reproduce
Steps to reproduce the behavior:

1. Create a binary file (non UTF-8) of exactly 64 bytes length
2. Create a new database using the above file as a keyfile using KeePass
3. Try to open the database with KeePassDX (using the same keyfile and password, obviously)
4. The database doesn't open

Expected behavior
The database should open correctly

Additional context
The code handling keyfiles of 64 bytes assumes it is a UTF-8 formatted hex string.
I don't know what it is supposed to do but from my testings, using AES for encryption and key derivation, it looks like the keyfile (of 64B) is hashed using SHA2-256 like keyfiles >64B

[J-Jamet]

Thank you for your issue. Unfortunately this functionality is not yet implemented in KeePassDX. I have to take the time to do it. I will plan it for future versions.

[J-Jamet]

Sorry, I thought you were talking about something else.

I relied on the KeePass documentation, here : https://keepass.info/help/base/keys.html

• 32 bytes. If the key file contains exactly 32 bytes, these are used as a 256-bit cryptographic key. This format requires the least disk space.

• Hexadecimal. If the key file contains exactly 64 hexadecimal characters (0-9 and A-F, in UTF-8/ASCII encoding, one line, no spaces), these are decoded to a 256-bit cryptographic key.

• Hashed. If a key file does not match any of the formats above, its content is hashed using a cryptographic hash function in order to build a key (typically a 256-bit key with SHA-256). This allows to use arbitrary files as key files.

So if the key file contains something other than these characters, it is normally hashed (3rd point).

[J-Jamet]

It seems that the second point is not correct, I will recode it. We should also contact KeePassDroid because it is part of it.

[J-Jamet]

After all of my testing it looks like the second condition is not included in KeePass2, I tested with a text file containing a key as shown, but it is recognized as a binary file. And if I directly create a file with 64 hexadecimal characters, it gives me a 32 bit file, so the first condition is called.
I'm just removing the second condition from the code as it just causes bugs ...