Public bug reported:

Dear all,

We need to fix hard-coded symmetric-key for challenge-response
authentication on `uru4000 driver`.

The driver uses a symmetric-key technique to encrypt the challenge data
using AES encryption algorithm for authentication.

"2nd generation MS devices added an AES-based challenge/response authentication 
scheme, where the device challenges the authenticity of the driver."
link: 
https://gitlab.freedesktop.org/libfprint/libfprint/blob/master/libfprint/drivers/uru4000.c#L348

Unfortunately, the driver creates risk by exposing a hard-coded secret
key as follows:

/* For 2nd generation MS devices */
static const unsigned char crkey[] = {
        0x79, 0xac, 0x91, 0x79, 0x5c, 0xa1, 0x47, 0x8e,
        0x98, 0xe0, 0x0f, 0x3c, 0x59, 0x8f, 0x5f, 0x4b,
};
link: 
https://gitlab.freedesktop.org/libfprint/libfprint/blob/master/libfprint/drivers/uru4000.c#L150

If the library wants to use challenge-response authentication, we need
to introduce a new key distribution scheme also.

Furthermore, I don't know why the library is really necessary to use it
such a resource constrained environment.


Lastly, is it a kind of CWE-321: Use of Hard-coded Cryptographic Key? (see 
https://cwe.mitre.org/data/definitions/321.html)

Many thanks!!

** Affects: libfprint (Ubuntu)
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Desktop Bugs, which is subscribed to libfprint in Ubuntu.
https://bugs.launchpad.net/bugs/1818936

Title:
  Found hard-coded secret-key for challenge-response on libfprint

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/libfprint/+bug/1818936/+subscriptions

-- 
desktop-bugs mailing list
desktop-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/desktop-bugs

Reply via email to