602 Commits

Author SHA1 Message Date
Robbie Harwood
5190df8510 blsuki: Check for mounted /boot in emu
Irritatingly, BLS defines paths relative to the mountpoint of the
filesystem which contains its snippets, not / or any other fixed
location. So grub-emu needs to know whether /boot is a separate
filesystem from / and conditionally prepend a path.

Signed-off-by: Robbie Harwood <rharwood@redhat.com>
Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-09-04 14:37:20 +02:00
Peter Jones
8cee1c284b blsuki: Add blscfg command to parse Boot Loader Specification snippets
The BootLoaderSpec (BLS) defines a scheme where different bootloaders can
share a format for boot items and a configuration directory that accepts
these common configurations as drop-in files.

The BLS Specification: https://uapi-group.org/specifications/specs/boot_loader_specification/

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Will Thompson <wjt@endlessm.com>
Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-09-04 14:37:20 +02:00
Luca Boccassi
f326c5c475 commands/bli: Set LoaderTpm2ActivePcrBanks runtime variable
It turns out checking from userspace is not 100% reliable to figure out
whether the firmware had TPM2 support enabled or not. For example with
EDK2 arm64, the default upstream build config bundles TPM2 support with
SecureBoot support, so if the latter is disabled, TPM2 is also unavailable.
But still, the ACPI TPM2 table is created just as if it was enabled. So,
/sys/firmware/acpi/tables/TPM2 exists and looks correct but there are no
measurements, neither the firmware nor the loader/stub can do them, and
/sys/kernel/security/tpm0/binary_bios_measurements does not exist.
So, userspace cannot really tell what was going on in UEFI mode.

The loader can use the apposite UEFI protocol to check, which is a more
definitive answer. Export the bitmask with the list of active banks as-is.
If it's not 0, then in userspace we can be sure a working TPM2 was available
in UEFI mode.

systemd-boot and systemd-stub v258 (current main) set this variable and
userspace portion consumes it to be able to tell what was available in
the firmware context.

Signed-off-by: Luca Boccassi <luca.boccassi@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-08-14 21:20:01 +02:00
Vladimir Serbinenko
0739d24cd1 libgcrypt: Adjust import script, definitions and API users for libgcrypt 1.11
This patches modifies the GRUB-libgcrypt API to match new libgcrypt 1.11.

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-07-11 23:12:50 +02:00
Gary Lin
451e227e53 tpm2_key_protector: Dump the PCR bank for key unsealing
TPM 2.0 Key File format stores the PCR selection in the parameters
for TPM2_PolicyPCR and it already contains the selected PCR bank.
Currently, tpm2_key_protector dumped the PCR bank specified by the
--bank option, and it may not be the PCR bank for key unsealing.

To dump the real PCR bank for key unsealing, this commit records the PCR
bank used by TPM2_PolicyPCR and dumps PCR values from that bank when
necessary.

Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-06-17 14:12:50 +02:00
Michael Chang
73d1c959ea cryptocheck: Add --quiet option
The option can be used to suppress output if we only want to test the
return value of the command.

Also, mention this option in the documentation.

Signed-off-by: Michael Chang <mchang@suse.com>
Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-05-06 17:14:04 +02:00
Maxim Suhanov
301b4ef25a disk/cryptodisk: Add the "erase secrets" function
This commit adds the grub_cryptodisk_erasesecrets() function to wipe
master keys from all cryptodisks. This function is EFI-only.

Since there is no easy way to "force unmount" a given encrypted disk,
this function renders all mounted cryptodisks unusable. An attempt to
read them will return garbage.

This is why this function must be used in "no way back" conditions.

Currently, it is used when unloading the cryptodisk module and when
performing the "exit" command (it is often used to switch to the next
EFI application). This function is not called when performing the
"chainloader" command, because the callee may return to GRUB. For this
reason, users are encouraged to use "exit" instead of "chainloader" to
execute third-party boot applications.

This function does not guarantee that all secrets are wiped from RAM.
Console output, chunks from disk read requests and other may remain.

This function does not clear the IV prefix and rekey key for geli disks.

Also, this commit adds the relevant documentation improvements.

Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-05-06 17:14:03 +02:00
Maxim Suhanov
10d778c4b4 commands/search: Add the diskfilter support
When the --cryptodisk-only argument is given, also check the target
device using the "cryptocheck" command, if available.

This extends the checks to common layouts like LVM-on-LUKS, so the
--cryptodisk-only argument transparently handles such setups.

Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-05-06 17:14:03 +02:00
Maxim Suhanov
ed691c0e0e commands/search: Introduce the --cryptodisk-only argument
This allows users to restrict the "search" command's scope to
encrypted disks only.

Typically, this command is used to "rebase" $root and $prefix
before loading additional configuration files via "source" or
"configfile". Unfortunately, this leads to security problems,
like CVE-2023-4001, when an unexpected, attacker-controlled
device is chosen by the "search" command.

The --cryptodisk-only argument allows users to ensure that the
file system picked is encrypted.

This feature supports the CLI authentication, blocking bypass
attempts.

Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-05-06 17:14:02 +02:00
Gary Lin
cd9cb944d9 tpm2_key_protector: Support NV index handles
Previously, NV index mode only supported persistent handles which are
only for TPM objects.

On the other hand, the "NV index" handle allows the user-defined data,
so it can be an alternative to the key file and support TPM 2.0 Key
File format immediately.

The following tpm2-tools commands store the given key file, sealed.tpm,
in either TPM 2.0 Key File format or the raw format into the NV index
handle 0x1000000.

  # tpm2_nvdefine -C o \
      -a "ownerread|ownerwrite" \
      -s $(stat -c %s sealed.tpm) \
      0x1000000
  # tpm2_nvwrite -C o -i sealed.tpm 0x1000000

To unseal the key in GRUB, add the "tpm2_key_protector_init" command to
grub.cfg:

  tpm2_key_protector_init --mode=nv --nvindex=0x1000000
  cryptomount -u <UUID> --protector tpm2

To remove the NV index handle:

  # tpm2_nvundefine -C o 0x1000000

Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-04-10 18:10:33 +02:00
Gary Lin
fa69deac56 tpm2_key_protector: Unseal key from a buffer
Extract the logic to handle the file buffer from the SRK recover
function to prepare to load the sealed key from the NV index handle,
so the NV index mode can share the same code path in the later patch.
The SRK recover function now only reads the file and sends the file
buffer to the new function.

Besides this, to avoid introducing more options for the NV index mode,
the file format is detected automatically before unmarshaling the data,
so there is no need to use the command option to specify the file format
anymore. In other words, "-T" and "-k" are the same now.

Also update grub.text to address the change.

Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-04-10 18:05:58 +02:00
Gary Lin
46c9f3a8da tpm2_key_protector: Add tpm2_dump_pcr command
The user may need to inspect the TPM 2.0 PCR values with the GRUB shell,
so the new tpm2_dump_pcr command is added to print all PCRs of the
specified bank.

Also update the document for the new command.

Signed-off-by: Gary Lin <glin@suse.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-04-10 18:03:55 +02:00
Gary Lin
617dab9e47 tpm2_key_protector: Dump PCRs on policy fail
PCR mismatch is one common cause of TPM key unsealing fail. Since the
system may be compromised, it is not safe to boot into OS to get the PCR
values and TPM eventlog for the further investigation.

To provide some hints, GRUB now dumps PCRs on policy fail, so the user
can check the current PCR values. PCR 0~15 are chosen to cover the
firmware, bootloader, and OS.

The sample output:

PCR Mismatch! Check firmware and bootloader before typing passphrase!
TPM PCR [sha256]:
  00: 17401f37710984c1d8a03a81fff3ab567ae9291bac61e21715b890ee28879738
  01: 7a114329ba388445a96e8db2a072785937c1b7a8803ed7cc682b87f3ff3dd7a8
  02: 11c2776849e8e24b7d80c926cbc4257871bffa744dadfefd3ed049ce25143e05
  03: 6c33b362073e28e30b47302bbdd3e6f9cee4debca3a304e646f8c68245724350
  04: 62d38838483ecfd2484ee3a2e5450d8ca3b35fc72cda6a8c620f9f43521c37d1
  05: d8a85cb37221ab7d1f2cc5f554dbe0463acb6784b5b8dc3164ccaa66d8fff0e1
  06: 9262e37cbe71ed4daf815b4a4881fb7251c9d371092dde827557d5368121e10e
  07: 219d542233be492d62b079ffe46cf13396a8c27e520e88b08eaf2e6d3b7e70f5
  08: de1f61c973b673e505adebe0d7e8fb65fde6c24dd4ab4fbaff9e28b18df6ecd3
  09: c1de7274fa3e879a16d7e6e7629e3463d95f68adcfd17c477183846dccc41c89
  10: 0000000000000000000000000000000000000000000000000000000000000000
  11: 0000000000000000000000000000000000000000000000000000000000000000
  12: 0000000000000000000000000000000000000000000000000000000000000000
  13: 0000000000000000000000000000000000000000000000000000000000000000
  14: 9ab9ebe4879a7f4dd00c04f37e79cfd69d0dd7a8bcc6b01135525b67676a3e40
  15: 0000000000000000000000000000000000000000000000000000000000000000
  16: 0000000000000000000000000000000000000000000000000000000000000000
  17: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
  18: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
  19: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
  20: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
  21: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
  22: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
  23: 0000000000000000000000000000000000000000000000000000000000000000
error: failed to unseal sealed key (TPM2_Unseal: 0x99d).
error: no key protector provided a usable key for luks (af16e48f-746b-4a12-aae1-c14dcee429e0).

If the user happens to have the PCR values for key sealing, the PCR dump
can be used to identify the changed PCRs and narrow down the scope for
closer inspection.

Please note that the PCR dump is trustworthy only if the GRUB binary is
authentic, so the user has to check the GRUB binary thoroughly before
using the PCR dump.

Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-04-10 18:03:38 +02:00
Glenn Washburn
488ac8bda9 commands/ls: Add directory header for dir args
Like the GNU ls, first print a line with the directory path before printing
files in the directory, which will not have a directory component, but only
if there is more than one argument.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-03-05 21:24:48 +01:00
Glenn Washburn
096bf59e4c commands/ls: Print full paths for file args
For arguments that are paths to files, print the full path of the file.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-03-05 21:24:48 +01:00
Glenn Washburn
90288fc48d commands/ls: Output path for single file arguments given with path
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-03-05 21:24:48 +01:00
Glenn Washburn
6337d84afa commands/ls: Show modification time for file paths
The modification time for paths to files was not being printed because
the grub_dirhook_info, which contains the mtime, was initialized to NULL.
Instead of calling print_file() directly, use fs->fs_dir() to call
print_file() with a properly filled in grub_dirhook_info. This has the
added benefit of reducing code complexity.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-03-05 21:24:48 +01:00
Glenn Washburn
cbfb031b14 commands/ls: Merge print_files_long() and print_files() into print_file()
Simplify the code by removing logic around which file printer to call.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-03-05 21:24:47 +01:00
Glenn Washburn
112d2069cf commands/ls: Return proper GRUB_ERR_* for functions returning type grub_err_t
Also, remove unused code.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-03-05 21:24:47 +01:00
Glenn Washburn
da9740cd52 commands/acpi: Use options enum to index command options
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-03-05 21:24:47 +01:00
Lukas Fink
7161e2437d commands/file: Fix NULL dereference in the knetbsd tests
The pointer returned by grub_elf_file() is not checked to verify it is
not NULL before use. A NULL pointer may be returned when the given file
does not have a valid ELF header.

Fixes: https://savannah.gnu.org/bugs/?61960

Signed-off-by: Glenn Washburn <development@efficientek.com>
Signed-off-by: Lukas Fink <lukas.fink1@gmail.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-26 19:34:57 +01:00
B Horn
5f31164aed commands/hexdump: Disable memory reading in lockdown mode
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-13 15:45:56 +01:00
B Horn
340e4d058f commands/memrw: Disable memory reading in lockdown mode
With the rest of module being blocked in lockdown mode it does not make
a lot of sense to leave memory reading enabled. This also goes in par
with disabling the dump command.

Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-13 15:45:56 +01:00
B Horn
34824806ac commands/minicmd: Block the dump command in lockdown mode
The dump enables a user to read memory which should not be possible
in lockdown mode.

Fixes: CVE-2025-1118

Reported-by: B Horn <b@horn.uk>
Reported-by: Jonathan Bar Or <jonathanbaror@gmail.com>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-13 15:45:56 +01:00
Lidong Chen
c68b7d2362 commands/test: Stack overflow due to unlimited recursion depth
The test_parse() evaluates test expression recursively. Due to lack of
recursion depth check a specially crafted expression may cause a stack
overflow. The recursion is only triggered by the parentheses usage and
it can be unlimited. However, sensible expressions are unlikely to
contain more than a few parentheses. So, this patch limits the recursion
depth to 100, which should be sufficient.

Reported-by: Nils Langius <nils@langius.de>
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-13 15:45:56 +01:00
Jonathan Bar Or
dad8f50297 commands/read: Fix an integer overflow when supplying more than 2^31 characters
The grub_getline() function currently has a signed integer variable "i"
that can be overflown when user supplies more than 2^31 characters.
It results in a memory corruption of the allocated line buffer as well
as supplying large negative values to grub_realloc().

Fixes: CVE-2025-0690

Reported-by: Jonathan Bar Or <jonathanbaror@gmail.com>
Signed-off-by: Jonathan Bar Or <jonathanbaror@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-13 15:45:56 +01:00
B Horn
2123c5bca7 commands/pgp: Unregister the "check_signatures" hooks on module unload
If the hooks are not removed they can be called after the module has
been unloaded leading to an use-after-free.

Fixes: CVE-2025-0622

Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-13 15:45:55 +01:00
B Horn
0bf56bce47 commands/ls: Fix NULL dereference
The grub_strrchr() may return NULL when the dirname do not contain "/".
This can happen on broken filesystems.

Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-13 15:45:55 +01:00
Lidong Chen
05be856a8c commands/extcmd: Missing check for failed allocation
The grub_extcmd_dispatcher() calls grub_arg_list_alloc() to allocate
a grub_arg_list struct but it does not verify the allocation was successful.
In case of failed allocation the NULL state pointer can be accessed in
parse_option() through grub_arg_parse() which may lead to a security issue.

Fixes: CVE-2024-45775

Reported-by: Nils Langius <nils@langius.de>
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Alec Brown <alec.r.brown@oracle.com>
2025-02-13 15:45:55 +01:00
B Horn
500e5fdd82 kern/dl: Fix for an integer overflow in grub_dl_ref()
It was possible to overflow the value of mod->ref_count, a signed
integer, by repeatedly invoking insmod on an already loaded module.
This led to a use-after-free. As once ref_count was overflowed it became
possible to unload the module while there was still references to it.

This resolves the issue by using grub_add() to check if the ref_count
will overflow and then stops further increments. Further changes were
also made to grub_dl_unref() to check for the underflow condition and
the reference count was changed to an unsigned 64-bit integer.

Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2025-02-13 15:45:55 +01:00
Stefan Berger
72092a8641 ieee1275/tcg2: Refactor grub_ieee1275_tpm_init()
Move tpm_get_tpm_version() into grub_ieee1275_tpm_init() and invalidate
grub_ieee1275_tpm_ihandle in case no TPM 2 could be detected. Try the
initialization only once so that grub_tpm_present() will always return
the same result. Use the grub_ieee1275_tpm_ihandle as indicator for an
available TPM instead of grub_ieee1275_tpm_version, which can now be
removed.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-11-28 22:37:50 +01:00
Stefan Berger
8c0b5f2003 ieee1275/ibmvpm: Move TPM initialization functions to own file
Move common initialization functions from the ibmvtpm driver module into
tcg2.c that will be moved into the new TCG2 driver in a subsequent patch.
Make the functions available to the ibmvtpm driver as public functions
and variables.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-11-28 22:21:41 +01:00
Stefan Berger
7344b3c7ce ieee1275: Consolidate repeated definitions of IEEE1275_IHANDLE_INVALID
Consolidate repeated definitions of IEEE1275_IHANDLE_INVALID that are cast
to the type grub_ieee1275_ihandle_t. On the occasion add "GRUB_" prefix to
the constant name.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-11-28 22:15:29 +01:00
Patrick Colp
fba3a474e0 tpm2_key_protector: Implement NV index
Currently with the TPM2 protector, only SRK mode is supported and
NV index support is just a stub. Implement the NV index option.

Note: This only extends support on the unseal path. grub-protect
has not been updated. tpm2-tools can be used to insert a key into
the NV index.

An example of inserting a key using tpm2-tools:

  # Get random key.
  tpm2_getrandom 32 > key.dat

  # Create primary object.
  tpm2_createprimary -C o -g sha256 -G ecc -c primary.ctx

  # Create policy object. `pcrs.dat` contains the PCR values to seal against.
  tpm2_startauthsession -S session.dat
  tpm2_policypcr -S session.dat -l sha256:7,11 -f pcrs.dat -L policy.dat
  tpm2_flushcontext session.dat

  # Seal key into TPM.
  cat key.dat | tpm2_create -C primary.ctx -u key.pub -r key.priv -L policy.dat -i-
  tpm2_load -C primary.ctx -u key.pub -r key.priv -n sealing.name -c sealing.ctx
  tpm2_evictcontrol -C o -c sealing.ctx 0x81000000

Then to unseal the key in GRUB, add this to grub.cfg:

  tpm2_key_protector_init --mode=nv --nvindex=0x81000000 --pcrs=7,11
  cryptomount -u <UUID> --protector tpm2

Signed-off-by: Patrick Colp <patrick.colp@oracle.com>
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
2024-11-28 21:50:55 +01:00
Gary Lin
550ada7d67 tpm2_key_protector: Support authorized policy
This commit handles the TPM2_PolicyAuthorize command from the key file
in TPM 2.0 Key File format.

TPM2_PolicyAuthorize is the essential command to support authorized
policy which allows the users to sign TPM policies with their own keys.
Per TPM 2.0 Key File [1], CommandPolicy for TPM2_PolicyAuthorize
comprises "TPM2B_PUBLIC pubkey", "TPM2B_DIGEST policy_ref", and
"TPMT_SIGNATURE signature". To verify the signature, the current policy
digest is hashed with the hash algorithm written in "signature", and then
"signature" is verified with the hashed policy digest and "pubkey". Once
TPM accepts "signature", TPM2_PolicyAuthorize is invoked to authorize the
signed policy.

To create the key file with authorized policy, here are the pcr-oracle [2]
commands:

  # Generate the RSA key and create the authorized policy file
  $ pcr-oracle \
	--rsa-generate-key \
	--private-key policy-key.pem \
	--auth authorized.policy \
	create-authorized-policy 0,2,4,7,9

  # Seal the secret with the authorized policy
  $ pcr-oracle \
	--key-format tpm2.0 \
	--auth authorized.policy \
	--input disk-secret.txt \
	--output sealed.key \
	seal-secret

  # Sign the predicted PCR policy
  $ pcr-oracle \
	--key-format tpm2.0 \
	--private-key policy-key.pem \
	--from eventlog \
	--stop-event "grub-file=grub.cfg" \
	--after \
	--input sealed.key \
	--output /boot/efi/efi/grub/sealed.tpm \
	sign 0,2,4,7,9

Then specify the key file and the key protector to grub.cfg in the EFI
system partition:

  tpm2_key_protector_init -a RSA --tpm2key=(hd0,gpt1)/efi/grub/sealed.tpm
  cryptomount -u <PART_UUID> -P tpm2

For any change in the boot components, just run the "sign" command again
to update the signature in sealed.tpm, and TPM can unseal the key file
with the updated PCR policy.

[1] https://www.hansenpartnership.com/draft-bottomley-tpm2-keys.html
[2] https://github.com/okirch/pcr-oracle

Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
2024-11-28 21:50:55 +01:00
Hernan Gatta
48e230c317 key_protector: Add TPM2 Key Protector
The TPM2 key protector is a module that enables the automatic retrieval
of a fully-encrypted disk's unlocking key from a TPM 2.0.

The theory of operation is such that the module accepts various
arguments, most of which are optional and therefore possess reasonable
defaults. One of these arguments is the keyfile/tpm2key parameter, which
is mandatory. There are two supported key formats:

1. Raw Sealed Key (--keyfile)
   When sealing a key with TPM2_Create, the public portion of the sealed
   key is stored in TPM2B_PUBLIC, and the private portion is in
   TPM2B_PRIVATE. The raw sealed key glues the fully marshalled
   TPM2B_PUBLIC and TPM2B_PRIVATE into one file.

2. TPM 2.0 Key (--tpm2key)
   The following is the ASN.1 definition of TPM 2.0 Key File:

   TPMPolicy ::= SEQUENCE {
     CommandCode   [0] EXPLICIT INTEGER
     CommandPolicy [1] EXPLICIT OCTET STRING
   }

   TPMAuthPolicy ::= SEQUENCE {
     Name    [0] EXPLICIT UTF8STRING OPTIONAL
     Policy  [1] EXPLICIT SEQUENCE OF TPMPolicy
   }

   TPMKey ::= SEQUENCE {
     type        OBJECT IDENTIFIER
     emptyAuth   [0] EXPLICIT BOOLEAN OPTIONAL
     policy      [1] EXPLICIT SEQUENCE OF TPMPolicy OPTIONAL
     secret      [2] EXPLICIT OCTET STRING OPTIONAL
     authPolicy  [3] EXPLICIT SEQUENCE OF TPMAuthPolicy OPTIONAL
     description [4] EXPLICIT UTF8String OPTIONAL,
     rsaParent   [5] EXPLICIT BOOLEAN OPTIONAL,
     parent      INTEGER
     pubkey      OCTET STRING
     privkey     OCTET STRING
   }

  The TPM2 key protector only expects a "sealed" key in DER encoding,
  so "type" is always 2.23.133.10.1.5, "emptyAuth" is "TRUE", and
  "secret" is empty. "policy" and "authPolicy" are the possible policy
  command sequences to construct the policy digest to unseal the key.
  Similar to the raw sealed key, the public portion (TPM2B_PUBLIC) of
  the sealed key is stored in "pubkey", and the private portion
  (TPM2B_PRIVATE) is in "privkey".

  For more details: https://www.hansenpartnership.com/draft-bottomley-tpm2-keys.html

This sealed key file is created via the grub-protect tool. The tool
utilizes the TPM's sealing functionality to seal (i.e., encrypt) an
unlocking key using a Storage Root Key (SRK) to the values of various
Platform Configuration Registers (PCRs). These PCRs reflect the state
of the system as it boots. If the values are as expected, the system
may be considered trustworthy, at which point the TPM allows for a
caller to utilize the private component of the SRK to unseal (i.e.,
decrypt) the sealed key file. The caller, in this case, is this key
protector.

The TPM2 key protector registers two commands:

  - tpm2_key_protector_init: Initializes the state of the TPM2 key
                             protector for later usage, clearing any
                             previous state, too, if any.

  - tpm2_key_protector_clear: Clears any state set by tpm2_key_protector_init.

The way this is expected to be used requires the user to, either
interactively or, normally, via a boot script, initialize/configure
the key protector and then specify that it be used by the "cryptomount"
command (modifications to this command are in a different patch).

For instance, to unseal the raw sealed key file:

  tpm2_key_protector_init --keyfile=(hd0,gpt1)/efi/grub/sealed-1.key
  cryptomount -u <PART1_UUID> -P tpm2

  tpm2_key_protector_init --keyfile=(hd0,gpt1)/efi/grub/sealed-2.key --pcrs=7,11
  cryptomount -u <PART2_UUID> -P tpm2

Or, to unseal the TPM 2.0 Key file:

  tpm2_key_protector_init --tpm2key=(hd0,gpt1)/efi/grub/sealed-1.tpm
  cryptomount -u <PART1_UUID> -P tpm2

  tpm2_key_protector_init --tpm2key=(hd0,gpt1)/efi/grub/sealed-2.tpm --pcrs=7,11
  cryptomount -u <PART2_UUID> -P tpm2

If a user does not initialize the key protector and attempts to use it
anyway, the protector returns an error.

Before unsealing the key, the TPM2 key protector follows the "TPMPolicy"
sequences to enforce the TPM policy commands to construct a valid policy
digest to unseal the key.

For the TPM 2.0 Key files, "authPolicy" may contain multiple "TPMPolicy"
sequences, the TPM2 key protector iterates "authPolicy" to find a valid
sequence to unseal key. If "authPolicy" is empty or all sequences in
"authPolicy" fail, the protector tries the one from "policy". In case
"policy" is also empty, the protector creates a "TPMPolicy" sequence
based on the given PCR selection.

For the raw sealed key, the TPM2 key protector treats the key file as a
TPM 2.0 Key file without "authPolicy" and "policy", so the "TPMPolicy"
sequence is always based on the PCR selection from the command
parameters.

This commit only supports one policy command: TPM2_PolicyPCR. The
command set will be extended to support advanced features, such as
authorized policy, in the later commits.

Cc: James Bottomley <jejb@linux.ibm.com>
Signed-off-by: Hernan Gatta <hegatta@linux.microsoft.com>
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
2024-11-28 21:50:55 +01:00
Leo Sandoval
f26b39860d commands/legacycfg: Avoid closing file twice
An internal (at Red Hat) static soure code scan detected an
use-after-free scenario:

  Error: USE_AFTER_FREE (CWE-416):
  grub-2.06/grub-core/commands/legacycfg.c:194: freed_arg: "grub_file_close" frees "file".
  grub-2.06/grub-core/commands/legacycfg.c:201: deref_arg: Calling "grub_file_close" dereferences freed pointer "file".
  #  199|         if (!args)
  #  200|   	{
  #  201|-> 	  grub_file_close (file);
  #  202|   	  grub_free (suffix);
  #  203|   	  grub_free (entrysrc);

So, remove the extra file close call.

Signed-off-by: Leo Sandoval <lsandova@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-10-31 16:08:36 +01:00
Daniel Kiper
1b1061409d i386/msr: Extract and improve MSR support detection code
Currently rdmsr and wrmsr commands have own MSR support detection code.
This code is the same. So, it is duplicated. Additionally, this code
cannot be reused by others. Hence, extract this code to a function and
make it public. By the way, improve a code a bit.

Additionally, use GRUB_ERR_BAD_DEVICE instead of GRUB_ERR_BUG to signal
an error because errors encountered by this new routine are not bugs.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-10-10 13:09:06 +02:00
Daniel Kiper
929fafdf5e i386/msr: Rename grub_msr_read() and grub_msr_write()
Use more obvious names which match corresponding instructions:
  * grub_msr_read()  => grub_rdmsr(),
  * grub_msr_write() => grub_wrmsr().

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-10-10 13:08:31 +02:00
Daniel Kiper
d96cfd7bf8 i386/msr: Merge rdmsr.h and wrmsr.h into msr.h
It does not make sense to have separate headers for individual static
functions. So, make one common place to store them.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-10-10 13:06:34 +02:00
Michael Chang
86ec48882b commands/tpm: Skip loopback image measurement
The loopback image is configured to function as a disk by being mapped
as a block device. Instead of measuring the entire block device we
should focus on tracking the individual files accessed from it. For
example, we do not directly measure block devices like hd0 disk but the
files opened from it.

This method is important to avoid running out of memory since loopback
images can be very large. Trying to read and measure the whole image at
once could cause out of memory errors and disrupt the boot process.

Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-10-10 13:04:37 +02:00
Michael Chang
9537f4403d commands/bli: Fix crash in get_part_uuid()
The get_part_uuid() function made an assumption that the target GRUB
device is a partition device and accessed device->disk->partition
without checking for NULL. There are four situations where this
assumption is problematic:

1. The device is a net device instead of a disk.
2. The device is an abstraction device, like LVM, RAID, or CRYPTO, which
   is mostly logical "disk" ((lvmid/<UUID>) and so on).
3. Firmware RAID may present the ESP to GRUB as an EFI disk (hd0) device
   if it is contained within a Linux software RAID.
4. When booting from a CD-ROM, the ESP is a VFAT image indexed by the El
   Torito boot catalog. The boot device is set to (cd0), corresponding
   to the CD-ROM image mounted as an ISO 9660 filesystem.

As a result, get_part_uuid() could lead to a NULL pointer dereference
and trigger a synchronous exception during boot if the ESP falls into
one of these categories. This patch fixes the problem by adding the
necessary checks to handle cases where the ESP is not a partition device.

Additionally, to avoid disrupting the boot process, this patch relaxes
the severity of the errors in this context to non-critical. Errors will
be logged, but they will not prevent the boot process from continuing.

Fixes: e0fa7dc84 (bli: Add a module for the Boot Loader Interface)

Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-By: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-09-05 16:08:17 +02:00
Hector Cao
86df79275d commands/efi/tpm: Re-enable measurements on confidential computing platforms
The measurements for confidential computing has been introduced in the
commit 4c76565b6 (efi/tpm: Add EFI_CC_MEASUREMENT_PROTOCOL support).
Recently the patch 30708dfe3 (tpm: Disable the tpm verifier if the TPM
device is not present) has been introduced to optimize the memory usage
when a TPM device is not available on platforms. This fix prevents the
tpm module to be loaded on confidential computing platforms, e.g. Intel
machines with TDX enabled, where the TPM device is not available.

In this patch, we propose to load the tpm module for this use case by
generalizing the tpm feature detection in order to cover CC platforms.
Basically, we do it by detecting the availability of the
EFI_CC_MEASUREMENT_PROTOCOL EFI protocol.

Fixes: https://savannah.gnu.org/bugs/?65821
Fixes: 30708dfe3 (tpm: Disable the tpm verifier if the TPM device is not present)

Signed-off-by: Hector Cao <hector.cao@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
2024-06-06 16:55:16 +02:00
Vladimir 'phcoder' Serbinenko
52e039e00b efi: Enable CMOS on x86 EFI platforms
The CMOS actually exists on most EFI platforms and in some cases is used to
store useful data that makes it justifiable for GRUB to read/write it.

As for date and time keep using EFI API and not CMOS one.

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2024-04-11 15:48:25 +02:00
Qiumiao Zhang
63fc253fc9 commands/acpi: Fix calculation of ACPI tables addresses when processing RSDT and XSDT
According to the ACPI specification the XSDT Entry field contains an array
of 64-bit physical addresses which points to other DESCRIPTION_HEADERs. However,
the entry_ptr iterator is defined as a 32-bit pointer. It means each 64-bit
entry in the XSDT table is treated as two separate 32-bit entries then. Fix the
issue by using correct addresses sizes when processing RSDT and XSDT tables.

Signed-off-by: Qiumiao Zhang <zhangqiumiao1@huawei.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-12-13 14:21:21 +01:00
Vladimir Serbinenko
7de6fe9635 types: Split aligned and packed guids
On ia64 alignment requirements are strict. When we pass a pointer to
UUID it needs to be at least 4-byte aligned or EFI will crash.
On the other hand in device path there is no padding for UUID, so we
need 2 types in one formor another. Make 4-byte aligned and unaligned types

The code is structured in a way to accept unaligned inputs
in most cases and supply 4-byte aligned outputs.

Efiemu case is a bit ugly because there inputs and outputs are
reversed and so we need careful casts to account for this
inversion.

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-11-08 05:04:24 +01:00
Vladimir Serbinenko
7ad30299da efi: Deduplicate configuration table search function
We do table search in many places doing exactly the same algorithm.
The only minor variance in users is which table is used if several entries
are present. As specification mandates uniqueness and even if it ever isn't,
first entry is good enough, unify this code and always use the first entry.

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-11-06 22:47:16 +01:00
Vladimir Serbinenko
c6cf807fc0 lsefi: Add missing static qualifier
known_protocols isn't used anywhere else and even misses grub_ prefix, so
let's make it local (static).

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-11-06 22:38:12 +01:00
Heinrich Schuchardt
a19e47ca41 commands/efi/lsefisystab: Print the UEFI specification revision in human readable form
E.g. 2.10 instead of 00020064 and 2.3.1 instead of 0002001f.

See UEFI 2.10 specification, chapter 4.2.1 EFI_TABLE_HEADER.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-10-12 17:22:45 +02:00
Glenn Washburn
4fdcb339bb commands/ls: Print "????????????" if unable to get file size
In long list mode, if the file can not be opened, the file is not printed.
Instead, print the file but print the size as "????????????".

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-08-14 18:12:49 +02:00