PureBoot Basic mode provides the full Linux userspace in firmware from
Heads without requiring verified boot or a Librem Key. Basic and
verified boot can be switched freely without changing firmware, such as
if a Librem Key is lost.
PureBoot Basic can apply firmware updates from a USB flash drive, and
having a complete Linux userspace enables more sophisticated recovery
options.
Basic mode boots to the first boot option by default, setting a default
is not required. This can be configured in the config GUI.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Add these two functions for use in config-gui.sh for future toggles.
load_config_value() obtains the value of a config setting, defaulting
to 'n'. get_config_display_action() displays 'Enable' or 'Disable'
depending on the current value.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
enable_usb_storage() inserts usb-storage.ko if not already loaded, then
waits for USB storage devices to appear.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
pause_automatic_boot() prompts that an automatic boot is about to occur
and allows the user to interrupt it.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Extract utilities from config-gui.sh for use in additional config
settings. read_rom() reads the current ROM with a message for failure.
replace_rom_file() replaces a CBFS file in a ROM. set_config() sets a
configuration variable in a file.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
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>
init must use busybox ash because it is used on legacy-flash boards.
Change shebang, move needed functions to ash_functions.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Multiple traps overwrite each other. While no tpmr functions have more
than one trap right now, it is fragile, and the quoting is complex due
to double expansion. Use at_exit to add exit handlers that accumulate
and do not require special quoting.
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
Provide mask_param() function to uniformly mask secret parameters,
while still indicating whether they are empty.
Extend DO_WITH_DEBUG to allow masking a password parameter by position,
using mask_param(). Move from ash_functions to functions (isn't used
by ash scripts).
Mask password parameters in kexec-unseal-key and tpmr seal. Use
mask_param() on existing masked params in tpmr.
Trim more troubleshooting output from tpm2_extend() in tpmr.
Clarify tpmr kexec_finalize echo; it's the TPM's platform heirarchy,
users might not know what this was referring to.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Busybox no longer has CONFIG_BASH since we are deploying bash on most
boards. We also should clearly indicate which scripts cannot use
bashisms.
Change shebang in x230-flash.init, t430-flash.init, flash.sh to
/bin/ash. Execute /bin/sh for interactive shells.
Move key functions needed by those scripts to initrd/etc/ash_functions.
Source ash_functions instead of functions in those scripts, so any
bashisms in other functions won't break parsing of the script in ash.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Use /bin/sh (ash in busybox builds) for interactive shells, not bash.
Preparation for trimming interactive features from bash to reduce size.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Trace parameters to seal/unseal and some key tpm2 invocations. Trace
invocation of tpmr seal/unseal for disk unlock key.
Add DO_WITH_DEBUG() to trace a command and parameters, then execute it.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
- /tmp/debug.log is created and appended by all TRACE and DEBUG calls in code
- fix some logic errors seen when no DEBUG entry were outputted in /tmp/debug.log
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>
-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
Adds check to detect device formatted as fat32 without partition table.
With fat32 fdisk does not print message about invalid partition table
and instead it'll print an empty table with header.
In both cases total output has the same length of 5 lines: 3 about
device info, 1 empty line and the 5th will be the table header or
invalid partition message.
Signed-off-by: Daniel Pineda <daniel.pineda@puri.sm>
Since it's not supposed to be shell safe, just display safe
inside double quotes, we can allow some more characters.
Also fix the escape character not being escaped.
busybox sha256sum will create a checksum file for uncommon file names
(e.g. /boot/foo"$\n"bar), but fail to verify that exact file.
https://bugs.busybox.net/show_bug.cgi?id=14226
Thus disallow all files in /boot/ with strange file names at the time of
signing for now. Verifying in the presence of new files with such file
names in /boot/ is no issue for the kexec_tree verification due to the
previously implemented escaping mechanism.
Attempt to fix the following issues:
1. unescaped file names may let an attacker display arbitrary
whiptail prompts --> escape, original code by @JonathonHall-Purism
2. whiptail itself allows escape characters such as \n
--> use an escape character not used by whiptail, i.e. #
3. performance issues caused by diff'ing too early -->
only generate a diff to display to the user, if an actual issue is
found
Extract exclusion for unpartitioned block device of partitioned media
to gui_functions, and exclude them even if kernel hasn't listed the
partitions yet. (Fixes flash/USB boot prompts incorrectly trying to
use the whole device for partitioned media the first time.)
Ignore block devices of size 0, like empty USB SD card readers.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
