Mdthbs

Installed Ubuntu with SIP disabled on MacBook 2017 - 0 issues, booted in seconds.

I have been building it out and created a problem while trying to make the WiFi work. At some point (it was very late) a combination of 3 things happened:

1. I enabled SIP


2. I attempted to install Broadcom 4360x drivers


3. I reinstalled Touch pad Drivers from GitHub repository

These are the items :

            [  +0.001007] input: Apple Inc. iBridge as /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3:1.2/0003:05AC:8600.0001/input/input7

            [  +0.057765] hid-generic 0003:05AC:8600.0001: input,hidraw0: USB HID v1.01 Keyboard [Apple Inc. iBridge] on usb-0000:00:14.0-3/input2

            [  +0.000196] hid-generic 0003:05AC:8600.0002: hiddev0,hidraw1: USB HID v1.01 Device [Apple Inc. iBridge] on usb-0000:00:14.0-3/input3

            [  +0.000230] PKCS#7 signature not signed with a trusted key

            [  +0.000002] PKCS#7 signature not signed with a trusted key

            [  +0.000288] appletb: Touchbar usb device added; dev=0003:05AC:8600.0001

            [  +0.000004] appletb: releasing current hid driver 'hid-generic'

and

            [  +0.002784] ACPI: Dynamic OEM Table Load:

            [  +0.000010] ACPI Exception: AE_NO_MEMORY, SSDT 0xFFFF948D2BD80800 Table is duplicated (20170831/tbdata-562)

            [  +0.000000] No Local Variables are initialized for Method [GCAP]

            [  +0.000000] Initialized Arguments for Method [GCAP]:  (1 arguments defined for method invocation)

located a UUID issue where the boot was taking 2 minutes after installing Kali on same device. It was related to the swap file ID changing.

Kali loads in 2.2 seconds on same device, also Debian, all green down the line.

PKCS#7 signature not signed with a trusted key

This message is typically coming from a piece of hardware. In your case it's likely the Nvidia graphics card that's emitting this.

This issue is discussed here in more detail, where 2 users were actually experiencing this issue, titled: PKCS Signature error/warnings running dmesg on Ubuntu Mate 18.04.

If you search the internet you'll come across dozens of people that are also experiencing this issue. From the looks of it this issue is still ongoing:

• After Upgrade to Mate 18.04 boot problems - not trusted key

NOTE: The issue seems to be associated with Ubuntu 18.04.

Source of message

Further searches for this message led me to this source code: ubuntu-xenial-kernel/certs/system_keyring.c. These lines are the ones emitting this:

if (!trusted) {

    pr_err("PKCS#7 signature not signed with a trusted keyn");

    ret = -ENOKEY;

}

Further searches will take you to sites that touch on signed kernel modules, such as this one - MODSIGN: Use PKCS#7 for module signatures

(2) Makes use of the PKCS#7 facility to provide module signatures.

Secure boot

Based on this AU Q&A titled: How to install module.ko module without kernel signature or kernel rebuild in Ubuntu 16.04? it was suggested you could either disable secure boot or sign the modules.

You either disable secure boot or sign the kernel module.

To disable secure boot you can follow directions in this Ubuntu wiki page titled: Testing Secure Boot.

References

• Kernel module signing facility

I was able to get around this issue by installing the cuda toolkit instead and adding its public key to the trusted keys.
Follow the directions here: https://developer.nvidia.com/cuda-downloads