Loaded malformed certificates and now bsdlib_init returns error on every boot

RE: Loaded malformed certificates and now bsdlib_init returns error on every boot

Håkon Alseth — Thu, 14 Nov 2019 08:39:43 GMT

Hi,

First of all; thank you very much for evaluating the issue and reporting this back to us with this level of detail.

I agree with you, this is frustrating, especially when the error is reported, but voided by the startup routine. I'll report this internally and have the bsdlib team evaluate what can be done in this scenario.

Kind regards,

Håkon

RE: Loaded malformed certificates and now bsdlib_init returns error on every boot

jbrzozoski — Wed, 13 Nov 2019 17:00:26 GMT

So, the error is less imposing than expected, but still frustrating.

The modem still seems to be functional even though bsd_init() returns an error on boot. If I ignore that result, all other functionality seems okay as long as I don't try to use the bad credentials. I can even use good credentials in security slots and use TLS connections.

I don't seem able to erase the bad credentials with nrf_inbuilt_key_delete, as it returns a result code of 5 (NRF_EIO), AT%CMNG is still able to do the job.

And once I erase the bad certificates I am able to reboot and bsd_init will succeed.

I think there needs to be some clarifications around which situation bsd_init can return failures and what functionality may or may not be usable at that point. I also think the modem firmware might want to self-correct by deleting malformed certificates so that a subsequent reboot will not show the failure, or perhaps succeed at boot time but just refuse to use the bad certificate.

RE: Loaded malformed certificates and now bsdlib_init returns error on every boot

jbrzozoski — Wed, 13 Nov 2019 16:40:18 GMT

at_client boots since it uses CONFIG_BSD_LIBRARY_SYS_INIT=y, and that ignores the result code from bsd_init:

	err = bsd_init();

	if (IS_ENABLED(CONFIG_BSD_LIBRARY_SYS_INIT)) {
		/* bsd_init() returns values from a different namespace
		 * than Zephyr's. Make sure to return something in Zephyr's
		 * namespace, in this case 0, when called during SYS_INIT.
		 * Non-zero values in SYS_INIT are currently ignored.
		 */
		return 0;
	}

	return err;

So ... it appears the modem is actually running "well enough" even when bsd_init returns an error.

RE: Loaded malformed certificates and now bsdlib_init returns error on every boot

jbrzozoski — Wed, 13 Nov 2019 16:31:46 GMT

Yeah, I can definitely re-create this by loading the malformed buffer. (I thought I couldn't briefly, but I had made a typo in my debug code.)

RE: Loaded malformed certificates and now bsdlib_init returns error on every boot

jbrzozoski — Wed, 13 Nov 2019 16:10:06 GMT

For some reason I don't understand yet, the at_client sample was able to get past bsd initialization okay, and I was able to remove the bad certificate store using AT%CMNG commands, and then reload my application and it is working again.

Device un-bricked!

I'm not sure what's different about how at_client calls bsd_init, and this still required JTAG on the board to recover.

I'm continuing to investigate...

RE: Loaded malformed certificates and now bsdlib_init returns error on every boot

jbrzozoski — Wed, 13 Nov 2019 16:00:44 GMT

I can't recover my modem.

I was able to reload mfwnrf9160101.zip just fine, but that didn't resolve the issue.

I then tried to load the special-built mfw_nrf9160_corrupt_fix.zip provided to me a while back, but that failed to load. I'm guessing that failed since it looks like a downgrade.

Can I please get a corrupt_fix that will load on top of 1.0.1?

Oh yeah, the initial issue was while running modem firmware v1.0.1.