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>
TPM password must be 1-32 characters. Loop if the password is not
valid or the repeated password doesn't match, so the user can try
again.
Move prompt_new_owner_password to functions and use in both gui-init
and tpm-reset.
Fixes#1336
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
These were still writing some debugging output containing flags and
PCRs even when debug was not enabled. Use DEBUG.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
We just set the TPM owner password, so there's no need to make the user
enter it again. Eliminates some failure modes if the user mistypes it
or enters the wrong password.
Allow optionally passing in the TPM owner password in tpmr seal,
check_tpm_counter(), seal-totp, and generate_totp_htop(). The user is
still prompted if the password is needed but was not provided, so
existing uses in other contexts continue to work unchanged.
Prompt for the password in reset_tpm() and pass it down to each of the
above.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
gui-init: do not consume two unseal attempt to unseal both totp and hotp + cosmetic changes (slow down TPM DA lockout)
kexec-seal-key: Add DEBUG statement for PCR precalc
seal-totp: add DEBUG statements regarding skipping of PCR5 and PCR6 involvement into TOTP/HOTP sealing ops
seal-hotpkey: Add DEBUG statements related to reuse of TOTP sealed secret
tpmr: add DO_WITH_DEBUG calls to output pcrread and extend calls
tpmr: typo correction stating TRACE calls for tpm2 where it was for tpm1
tpmr: add DO_WITH_DEBUG calls for calcfuturepcr
functions: Cosmetic fix on pause_recovery asking user to press Enter to go to recovery shell on host console when board defines CONFIG_BOOT_RECOVERY_SERIAL
Not so related but part of output review and corrections:
kexec-insert-key: cosmetic changes prepending "+++" to disk related changes
kexec-save-default: cosmetic changes prepending "+++" to disk related changes
config/coreboot-qemu-tpm*.config: add ccache support for faster coreboot rebuild times
Most logic throughout Heads doesn't need to know TPM1 versus TPM2 (and
shouldn't, the differences should be localized). Some checks were
incorrect and are fixed by this change. Most checks are now unchanged
relative to master.
There are not that many places outside of tpmr that need to
differentiate TPM1 and TPM2. Some of those are duplicate code that
should be consolidated (seal-hotpkey, unseal-totp, unseal-hotp), and
some more are probably good candidates for abstracting in tpmr so the
business logic doesn't have to know TPM1 vs. TPM2.
Previously, CONFIG_TPM could be variously 'y', 'n', or empty. Now it
is always 'y' or 'n', and 'y' means "any TPM". Board configs are
unchanged, setting CONFIG_TPM2_TOOLS=y implies CONFIG_TPM=y so this
doesn't have to be duplicated and can't be mistakenly mismatched.
There were a few checks for CONFIG_TPM = n that only coincidentally
worked for TPM2 because CONFIG_TPM was empty (not 'n'). This test is
now OK, but the checks were also cleaned up to '!= "y"' for robustness.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Resetting the TPM invalidates the primary handle hash, and
kexec-save-default only generates a hash if none exists. Remove the
hash file when it is invalidated.
OEM reset and "Reset Configuration" both already remove all kexec
files.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
-coreboot support of TPM v2.0 (shared config for TPM2 support across all 4 previous variations)
-swtpm set to be launched under TPM v2.0 mode under board config
-Documentation file under each board.md softlinks to qemu-coreboot-fbwhiptail-tpm1.md (which has been generalized)
This is skeleton for TPM v2 integration under Heads
-------------
WiP
TODO:
- libcurl cannot be built as a tpm2-tools dependency as of now not sure why. curl currently needs to be added in board config to be built
- Note: tpm-reset (master and here) needs some review, no handle of no tpm use case. Caller is responsible to not call it otherwise does nothing
- init tries to bind fd and fails currently
- Note: Check if whiptail is different of fbwhiptail in clearing screen. As of now every clear seems to be removed, still whiptail clears previous console output
- When no OS' /boot can be mounted, do not try to TPM reset (will fail)
- seal-hotpkey is not working properly
- setting disk unlock key asks for TPM ownership passphrase (sealing in NV requires ownership, but text is misleading user as if reowning TPM)
- We should cache input, feed tpm behind the scene and wipe passphrase and state clearly that this is TPM disk unlock kye passphrase.
- primary key from TPM2 is invalid most of the time from kexec-select-boot and verifying global hashes but is setuped correctly at disk unlock key setup
- would be nice to take advantage of bash function tracing to understand where we are for debugging purposes, code takes ash in consideration only
- tpmr says it implements nv calls but actually doesn't. Removing those falsely wrapped functions would help.
- Implementing them would be better
- REVIEW TODOS IN CODE
- READD CIRCLECI CONFIG
Current state:
- TPM unseal works without disk unlock key and generates TOTP properly (was missing die condition at unseal to not produce always good TOTP even if invalid)
- TPM disk encryption key fails. Hypothesis is that sealing with USB drivers loaded and measures in inconsistent with sealed with/without.
- TPM disk unsealing happens without USB modules being loaded in non-HOTP setup. This fails.
- Current tests are with fbwhiptail (no clear called so having traces on command line of what happens)
- Testing with HOTP implementation for sealing/unsealing since that forces USB module loads on each boot to remove this from failing possibilities
- Add TRACE function tracing output under etc/functions, depending on CONFIG_ENABLE_FUNCTION_TRACING_OUTPUT enabled in board configs
- Replace current DEBUG to TRACE calls in code, reserving DEBUG calls for more verbose debugging later on (output of variables etc)
- add 'export CONFIG_ENABLE_FUNCTION_TRACING_OUTPUT=y' in qemu-coreboot(fb)whiptail-tpm1(-hotp) boards to see it in action
If the user selects "continue to main menu" from an error, do not show
any more error prompts until reaching the main menu.
We still try to initialize everything (GPG, TOTP, HOTP) so that the
main menu can still show TOTP/HOTP if GPG is not configured, etc., but
no more prompts are shown after selecting "continue to main menu".
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
- initrd/bin/gui-init : Add two additional menu options to LUKS reencrypt and LUKS passphrase change, calling functions of initrd/bin/reencrypt-luks
- initrd/bin/gui-init : Add option F for EOM Factory Reset / Reownership when no public key is exported by key-init
oem-factory-reset: adapt code so that custom passphrases can be provided by user without changing oem factory reset workflow.
oem-factory-reset: output provisioned secrets on screen at the end of of the process.
oem-factory-reset: warn user of what security components will be provisioned with defaults/customs PINs prior of choosing not after
gui-init and oem-factory-reset: change OEM Factory Reset -> OEM Factory Reset / Re-Ownership to cover actual use cases
It is going to be enabled later anyway (if CONFIG_HOTPKEY=y), so it can
also be simplified by enabling it at the very beginning.
This enables USB keyboard consistently during all boot menus, including
the "No Bootable OS Found" prompt. It isn't a big deal for "normal"
laptop usage, but it is important for automatic tests and also
non-laptop systems.
When files in /boot fail hash verification, the list of files
can sometimes overflow the whiptail msgbox, preventing the
prompt and buttons to update checksums from showing. To mitigate
this, if # of files is > 10, use less to show the file list and
present a separate prompt to update the checksums once the file
list has been viewed.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
After updating/flashing a new ROM, a new TOTP secret must be generated,
but the $TOTP variable needs to be updated afterwards, otherwise it
will show the previous failure which led to the new secret being
created.
Fix this by re-calling update_totp() after generating a new secret
or resetting the TPM.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
If user selects to manually update the TOTP via the menu,
we should do it regardless of elapsed time from previous
check. Otherwise, HOTP will be checked regardless of validity
of TOTP.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Modify update_checksums() to return 0/1 on success/failure, and modify
callers to notify the user on error with a GUI msg.
Set background color as appropriate in gui-init.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Persist the background color (and error state) through
the main menu and all submenus. Use warning
background color for destructive operations, error color
for errors.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Checking the keyring for a GPG and updating the TOTP/HTOP
status need only happen once at initial boot; the latter
can be updated at any later time from the main menu itself.
Having them repeated each loop of the main menu is unnecessary
(and often annoying). Likewise, the default auto boot can be
moved and the first_pass (and unused MAIN_MENU_OPTIONS)
variable dropped.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Now that all menu options are encapsulated in shell
functions, move menu handling from the main loop to
inside the menu/submenu function itself.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Break menus and menu items into functions where possible.
Improves readability of code / functional flow, and
makes future refactoring easier.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Name better reflects function purpose, allows 'update_totp'
to be used to actually update the TOTP code.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
if CONFIG_AUTO_BOOT_TIMEOUT exists and is set, and if HOTP
validation was successful, then attempt to boot the default
target after CONFIG_AUTO_BOOT_TIMEOUT seconds if not interrupted
by key press
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Check for presence of CONFIG_BOOT_DEV, and if missing or
unable to be mounted, present the user with a menu offering the
option to select another disk, boot from USB, continue to
main menu, or drop to a recovery shell.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Set and export currently-used defaults in gui-init, but still
allow for inidividual boards to override via config if desired.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
This will allow it to be used elsewhere within the UI.
Rename CONFIG_BOOT_GUI_MENU_NAME to better indicate use/function.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
