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Grepping on just 'Disk' can lead to disk UUID identifier strings
being added to /tmp/disklist, which then fail to parse later on.
Avoid this by grepping on 'Disk /dev' instead.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

Kyle Rankin authored Nov 25, 2019 and Matt Devillier committed Jun 23, 2021

On machines without a TPM, we'd still like some way for the BIOS to
attest that it has not been modified. With a Librem Key, we can have the
BIOS use its own ROM measurement converted to a SHA256sum and truncated
so it fits within an HOTP secret. Like with a TPM, a malicious BIOS with
access to the correct measurements can send pre-known good measurements
to the Librem Key.

This approach provides one big drawback in that we have to truncate the
SHA256sum to 20 characters so that it fits within the limitations of
HOTP secrets. This means the possibility of collisions is much higher
but again, an attacker could also capture and spoof an existing ROM's
measurements if they have prior access to it, either with this approach
or with a TPM.
Signed-off-by: Kyle Rankin <kyle.rankin@puri.sm>

Signed-off-by: Tom Hiller <thrilleratplay@gmail.com>

Update_checksum was already changing files in /boot, befor checking for
gpg card. If no card is present, the user will end up in the recovery
next time instead of getting the same dialog again. Therefore, the
confirm_gpg_card should be checked before altering files.

The dead -u flag/$update_counter is used to mark the necessisty to
update the hash files now.

Currently, exiting the recovery shell results in a kernel panic,
necessitating a hard reset / power cycle. As this is less than ideal,
drop the exec and add a loop to restart the shell.

Addresses issue #833

Tested under qemu-coreboot-fbwhiptail
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

Using 'let' in these scripts fails when evaluating to zero
for some reason, so replace with '$(())' which works as intended.

Test: Boot device selection menu shown properly when
new/unpartitioned drive installed.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

For the handful of operations which need to be done with /boot
as the pwd, encapsulate them in subshells to ensure the pwd
doesn't unexpectedly change for other operations, as functions
which need to mount/unmount /boot may fail if the pwd isn't root.

Also, set the pwd to root at the start of detect_boot_device as an
added safety measure.

Test: run oem-factory-reset function, ensure it doesn't fail to
detect boot device due to incorrect working directory.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

If kexec-sign-config fails due to GPG key not present,
the double die() results in a kernel panic (and if it didn't,
/boot would be left mounted RW). Fix this by removing call to
die() and ensuring /boot remounted RO regardless checksum
update success or failure.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

Add function to detect boot device. Start by checking
CONFIG_BOOT_DEV, then iterate thru all bootable partitions.
Check if partition is mountable, contains grub directory.

Update CONFIG_BOOT_DEV and mount on /boot if successful.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

Initial card detection can sometimes fail, so prompt the user
to remove/reinsert their GPG card before retrying. Since
errexit is likely set, disable it prior to calling --card-status so
we can handle the error ourself, then re-set if necessary when done.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

Move the non-GUI component of update_checksums() to
/etc/functions so it can be reused outside of gui-init.

Add check that /boot/kexec_default_hashes.txt exists before parsing
it, since doesn't exist if there's no default boot target set yet.
Eliminates spurious error text and/or premature exit depending on
state of errexit.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

If we sort | uniq config options, then the lowest in the sort will get
precedence, when what we want is for user preferences to override system
ones.

There are cases when grepping for an option in the config file where
grep will not find it, which is fine in this case, but without adjusting
the exit code in that case it can make an entire script bail out.

We need to handle the case where the specific config file doesn't exist,
or else grep fails, so we touch the file ahead of time. Mounting the usb
storage caused problems when you re-enter the menu a second time, so we
will just load the storage module.

As part of the config gui we want to be able to have the system define
new config options without them being lost if the user makes their own
changes in CBFS. To allow that this change creates a function initiated
in init that combines all /etc/config* files into /tmp/config. All
existing scripts have been changed to source /tmp/config instead of
/etc/config. The config-gui.sh script now uses /etc/config.user to hold
user configuration options but the combine_configs function will allow
that to expand as others want to split configuration out further.

As it stands here are the current config files:

/etc/config -- Compiled-in configuration options
/etc/config.user -- User preferences that override /etc/config
/tmp/config -- Running config referenced by the BIOS, combination
               of existing configs

The Librem Key is a custom device USB-based security token Nitrokey is
producing for Purism and among other things it has custom firmware
created for use with Heads. In particular, when a board is configured
with CONFIG_LIBREMKEY, this custom firmware allows Heads to use the
sealed TOTP secret to also send an HOTP authentication to the Librem
Key. If the HOTP code is successful, the Librem Key will blink a green
LED, if unsuccessful it will blink red, thereby informing the user that
Heads has been tampered with without requiring them to use a phone to
validate the TOTP secret.

Heads will still use and show the TOTP secret, in case the user wants to
validate both codes (in case the Librem Key was lost or is no longer
trusted). It will also show the result of the HOTP verification (but not
the code itself), even though the user should trust only what the Librem
Key displays, so the user can confirm that both the device and Heads are
in sync. If HOTP is enabled, Heads will maintain a new TPM counter
separate from the Heads TPM counter that will increment each time HOTP
codes are checked.

This change also modifies the routines that update TOTP so that if
the Librem Key executables are present it will also update HOTP codes
and synchronize them with a Librem Key.

Currently the TPM counter label is hard-coded. By changing it to a
variable in this function we can reuse all of the TPM counter functions
to create other monotonic counters in the TPM (if the hardware supports
it) with custom labels.

There was a bug in the "force" boot mode where it would still fail if
signatures didn't match. This was because the check_config function
validates the signatures for kexec files. I've added a few conditionals
here so that in the case of a forced boot mode, we can bypass those
signature checks that would prevent boot and error out to a recovery
console.

Enabled recovery serial console (tested on kgpe-d16)
Minor fix to kexec-boot to correct xen boot
Remove busybox power utils

Guarded linuxboot specific init entries
Removed Makefile entries into separate file (conflicts with srcing /etc/config)
Added CONFIG_BOOT_LOCAL/_REMOTE to control interface setup
Fixed CONFIG_TPM usage

if "CONFIG_TPM=y" is not present in the config file, functionalities
needing TPM could be disabled, while leaving other functionalities intact.

This will make Heads a more general-usage bootloader payload atop coreboot.

USB smart card readers are most full speed devices, and there is no
"rate-matching hubs" beneath the root hub on older (e.g. GM45) plat-
forms, which has companion OHCI or UHCI controllers and needs cor-
responding drivers to communicate with card readers directly plugged
into the motherboard, otherwise a discrete USB hub should be inserted
between the motherboard and the reader.

This time I make inserting linux modules for OHCI and UHCI controllable
with option CONFIG_LINUX_USB_COMPANION_CONTROLLER.

A linux config for x200 is added as an example.

Tested on my x200s and elitebook revolve 810g1.

if "CONFIG_TPM=y" is not present in the config file, functionalities
needing TPM could be disabled, while leaving other functionalities intact.

This will make Heads a more general-usage bootloader payload atop coreboot.

Closes #222

Changed the checking of required hashes or required rollback state
to be right before boot, allowing the user to sign/set defaults
in interactive mode.

Also cleaned up usages of recovery and fixed iso parameter
regression.

Similar to qubes-update, it will save then verify the hashes of
the kexec files. Once TOTP is verified, a normal boot will verify
that the file hashes and all the kexec params match and if
successful, boot directly to OS.

Also added a config option to require hash verification for
non-recovery boots, failing to recovery not met.

Supports booting from USB media using either the root device or
a signed ISO as the boot device.  Boot options are parsed with
quick/dirty shell scripts to infer kexec params.

Closes #195 and begins to address #196