Bundle Signatures

A few notable improvements to bundle signing landed in RAUC 1.3. By default, RAUC does not check the certificate's key usage attributes. When the bundle signing certificates are part of a larger, shared PKI, RAUC can now require specific purposes like codeSigning, thereby allowing better policy enforcement via the PKI. Checking of key usage attributes can be enabled with the check-purpose configuration option:

[keyring]
path=/path/to/ca.cert
check-purpose=codesign

Also, you can now require checking of CRLs during installation (which is disabled by default in OpenSSL). Setting the check-crl configuration option changes this:

[keyring]
path=/path/to/ca.cert-with-crl
check-crl=true

If the keyring already contains a CRL, but checking is not enabled, a warning will now be printed.

For bundles with expired certificates, you can now use the --no-verifiy option for rauc resign to easily create a fresh signature.

As the OpenSSL project dropped support for all version before 1.1.1, we have now removed support for those as well. If you still use a deprecated and thus insecure OpenSSL version, this is the time to upgrade!

Further Enhancements

A couple of limitations in bundle and image size handling RAUC had when running on a 32 bit system were removed.

For those running on very constrained systems, some options for reducing the size of the RAUC binary were added.

If you want to customize bundle creation, this version adds some options for that: --mksquashfs-args="-option-to-add" for mksquashfs, and --casync-args="--another-option" for casync.

A couple of minor bugs and memory leaks were fixed, especially an error reporting bug that may have triggered during bundle verification if an invalid keyring was configured which lead to a non-intuitive error message "rauc-ERROR **: Not enough substeps: check_bundle".

Testing

The main test suite was previously run in UML (User Mode Linux), but this turned out to be difficult to support in the various build environments. This was now replaced by running a normal kernel in QEMU to better decouple it from the host system and kernel while preparing CI testing of more areas, like NAND writing support via the kernel's nandsim module.

Thanks to all contributors since v1.2: Arnaud Rebillout, Christopher Obbard, Enrico Jörns, Jan Kundrát, Jan Lübbe, Louis des Landes, Marco Felsch, Martin Hundebøll, Michael Heimpold, Michael Tretter, Rasmus Villemoes, Rouven Czerwinski, Trent Piepho, Ulrich Ölmann