Commit graph

23 commits

Author SHA1 Message Date
Ilias Apalodimas
9677192c14 efi_loader: enable QueryVariableInfo at runtime for file backed variables
Since commit c28d32f946 ("efi_loader: conditionally enable SetvariableRT")
we are enabling the last bits of missing runtime services.
Add support for QueryVariableInfo which we already support at boottime
and we just need to mark some fucntions available at runtime and move
some checks around.

It's worth noting that pointer checks for maxmimum and remaining
variable storage aren't when we store variables on the RPMB, since the
Secure World backend is already performing them.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2024-05-01 07:40:05 +02:00
Ilias Apalodimas
00da8d65a3 efi_loader: add an EFI variable with the file contents
Previous patches enabled SetVariableRT using a RAM backend.
Although EBBR [0] defines a variable format we can teach userspace tools
and write the altered variables, it's better if we skip the ABI
requirements completely.

So let's add a new variable, in its own namespace called "VarToFile"
which contains a binary dump of the updated RT, BS and, NV variables
and will be updated when GetVariable is called.

Some adjustments are needed to do that.
Currently we discard BS-only variables in EBS(). We need to preserve
those on the RAM backend that exposes the variables. Since BS-only
variables can't appear at runtime we need to move the memory masking
checks from efi_var_collect() to efi_get_next_variable_name_mem()/
efi_get_variable_mem() and do the filtering at runtime.

We also need an efi_var_collect() variant available at runtime, in order
to construct the "VarToFile" buffer on the fly.

All users and applications (for linux) have to do when updating a variable
is dd that variable in the file described by "RTStorageVolatile".

Linux efivarfs uses a first 4 bytes of the output to represent attributes
in little-endian format. So, storing variables works like this:

$~ efibootmgr -n 0001
$~ dd if=/sys/firmware/efi/efivars/VarToFile-b2ac5fc9-92b7-4acd-aeac-11e818c3130c of=/boot/efi/ubootefi.var skip=4 bs=1

[0] https://arm-software.github.io/ebbr/index.html#document-chapter5-variable-storage

Suggested-by: Ard Biesheuvel <ardb@kernel.org> # dumping all variables to a variable
Co-developed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> # contributed on efi_var_collect_mem()
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2024-04-20 08:22:24 +02:00
Heinrich Schuchardt
2608015921 efi_loader: typo mstching
%s/mstching/matching/

Reported-by: E Shattow <lucent@gmail.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2024-04-20 08:21:59 +02:00
Ilias Apalodimas
df1076af36 efi_loader: move efi_var_collect to common functions
efi_var_collect() was initially placed in efi_var_file.c, since back
then we only supported efi variables stored in a file. Since then we
support variables stored in an RPMB as well and use that function to
collect variables that should be present at runtime.

So let's move it around in efi_var_common.c which makes more sense

Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ilias Apalodimas <apalos@gmail.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2024-04-13 11:03:12 +02:00
Heinrich Schuchardt
19327c1f90 efi_loader: all variable attributes are 32bit
GetVariable() and SetVariable() use an uint32_t value for attributes.
The UEFI specification defines the related constants as 32bit.

Add the missing EFI_VARIABLE_ENHANCED_AUTHENTICATED_ACCESS constant.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2024-04-08 13:03:11 +02:00
Tom Rini
c38cb227d3 efi_loader: Remove <common.h>
We largely do not need <common.h> in these files, so drop it. The only
exception here is that efi_freestanding.c needs <linux/types.h> and had
been getting that via <common.h>.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
2023-12-21 08:54:37 -05:00
Masahisa Kojima
454a9442fb efi_loader: update attribute check for QueryVariableInfo()
Current U-Boot supports two EFI variable service, U-Boot own
implementation and op-tee based StMM variable service.

With ACS Security Interface Extension(SIE) v22.10_SIE_REL1.1.0,
there are several failure items of QueryVariableInfo().

Current attribute check for QueryVariableInfo() was implemented
based on the Self Certification Test (SCT) II Case Specification,
June 2017, chapter 4.1.4 QueryVariableInfo().
This test case specification is outdated and don't align at all
with the SCT test case code, and UEFI specification v2.10 does
not clearly define the priority of the attribute check.

For U-Boot standard case that EFI variables are stored in a file
in the ESP, this commit modifies the attribute check to get align
to the EDK2 implementation.

For latter case(op-tee based StMM variable service), parameter check
should be delegated to StMM.

Now all ACS SIE QueryVariableInfo() test cases passed both EFI variable
storage implementations.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Acked-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2023-02-10 13:05:39 +01:00
Simon Glass
156ccbc3c4 efi: Use 16-bit unicode strings
At present we use wide characters for unicode but this is not necessary.
Change the code to use the 'u' literal instead. This helps to fix build
warnings for sandbox on rpi.

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2022-02-03 12:16:01 -05:00
Heinrich Schuchardt
ce00a7401a efi_loader: use %pUs for printing GUIDs
For printing GUIDs with macro EFI_ENTRY use %pUs instead of %pUl to provide
readable debug output.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2022-01-19 16:16:33 +01:00
Heinrich Schuchardt
e618d1d285 efi_loader: function to get GUID for variable name
In multiple places we need the default GUID matching a variable name.
The patch provides a library function. For secure boot related variables
like 'PK', 'KEK', 'db' a lookup table is used. For all other variable
names EFI_GLOBAL_VARIABLE is returned.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2021-10-25 21:13:06 +02:00
Heinrich Schuchardt
d47671c631 efi_loader: treat UEFI variable name as const
UEFI variable names are typically constants and hence should be defined as
const. Unfortunately some of our API functions do not define the parameters
for UEFI variable names as const. This requires unnecessary conversions.

Adjust parameters of several internal functions to tre UEFI variable names
as const.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2021-10-25 21:13:06 +02:00
Heinrich Schuchardt
7219856dae efi_loader: correct determination of secure boot state
When U-Boot is started we have to use the existing variables to determine
in which secure boot state we are.

* If a platform key PK is present and DeployedMode=1, we are in deployed
  mode.
* If no platform key PK is present and AuditMode=1, we are in audit mode.
* Otherwise if a platform key is present, we are in user mode.
* Otherwise if no platform key is present, we are in setup mode.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2021-09-04 12:03:57 +02:00
Heinrich Schuchardt
b191aa429e efi_loader: efi_auth_var_type for AuditMode, DeployedMode
Writing variables AuditMode and DeployedMode serves to switch between
Secure Boot modes. Provide a separate value for these in efi_auth_var_type.

With this patch the variables will not be read from from file even if they
are marked as non-volatile by mistake.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2021-09-04 12:03:57 +02:00
Heinrich Schuchardt
9ef82e2947 efi_loader: don't load signature database from file
The UEFI specification requires that the signature database may only be
stored in tamper-resistant storage. So these variable may not be read
from an unsigned file.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2021-09-04 12:03:57 +02:00
Masami Hiramatsu
417a3c24c9 efi_loader: Improve the parameter check for QueryVariableInfo()
Improve efi_query_variable_info() to check the parameter settings and
return correct error code according to the UEFI Specification 2.9,
and the Self Certification Test (SCT) II Case Specification, June
2017, chapter 4.1.4 QueryVariableInfo().

Reported-by: Kazuhiko Sakamoto <sakamoto.kazuhiko@socionext.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2021-07-02 09:37:01 +02:00
Masahisa Kojima
f6081a8a1e efi_loader: expose efi_image_parse() even if UEFI Secure Boot is disabled
This is preparation for PE/COFF measurement support.
PE/COFF image hash calculation is same in both
UEFI Secure Boot image verification and measurement in
measured boot. PE/COFF image parsing functions are
gathered into efi_image_loader.c, and exposed even if
UEFI Secure Boot is not enabled.

This commit also adds the EFI_SIGNATURE_SUPPORT option
to decide if efi_signature.c shall be compiled.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2021-05-25 13:06:57 +02:00
Ilias Apalodimas
37c3ca5c0b efi_loader: Add helper functions for EFI
A following patch introduces a different logic for loading initrd's
based on the EFI_LOAD_FILE2_PROTOCOL.
Since similar logic can be applied in the future for other system files
(i.e DTBs), let's add some helper functions which will retrieve and
parse file paths stored in EFI variables.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2021-03-25 20:14:25 +01:00
AKASHI Takahiro
dd92aad81c efi_loader: add copyright notice
Some amount of code was moved/derived from efi_variable.c regarding
UEFI secure boot, in particluar in the commit 012c56ac76 ("efi_loader:
restructure code for TEE variables").
So add the orignal author's copyright notice.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-08-08 19:03:24 +02:00
Ilias Apalodimas
e01aed47d6 efi_loader: Enable run-time variable support for tee based variables
We recently added functions for storing/restoring variables
from a file to a memory backed buffer marked as __efi_runtime_data
commit f1f990a8c9 ("efi_loader: memory buffer for variables")
commit 5f7dcf079d ("efi_loader: UEFI variable persistence")

Using the same idea we now can support GetVariable() and GetNextVariable()
on the OP-TEE based variables as well.

So let's re-arrange the code a bit and move the commmon code for
accessing variables out of efi_variable.c. Create common functions for
reading variables from memory that both implementations can use on
run-time. Then just use those functions in the run-time variants of the
OP-TEE based EFI variable implementation and initialize the memory
buffer on ExitBootServices()

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-08-01 11:57:41 +02:00
Heinrich Schuchardt
99bfab8b58 efi_loader: identify PK, KEK, db, dbx correctly
To determine if a varible is on the of the authentication variables
PK, KEK, db, dbx we have to check both the name and the GUID.

Provide a function converting the variable-name/guid pair to an enum and
use it consistently.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-16 12:37:02 +02:00
Heinrich Schuchardt
012c56ac76 efi_loader: restructure code for TEE variables
When using secure boot functions needed both for file and TEE based UEFI
variables have to be moved to the common code module efi_var_common.c.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-16 12:37:02 +02:00
Heinrich Schuchardt
01df8cf336 efi_loader: separate UEFI variable API from implemementation
Separate the remaining UEFI variable API functions GetNextVariableName and
QueryVariableInfo() from internal functions implementing them.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-11 23:14:16 +02:00
Heinrich Schuchardt
f2d2b3a11c efi_loader: prepare for read only OP-TEE variables
We currently have two implementations of UEFI variables:

* variables provided via an OP-TEE module
* variables stored in the U-Boot environment

Read only variables are up to now only implemented in the U-Boot
environment implementation.

Provide a common interface for both implementations that allows handling
read-only variables.

As variable access is limited to very few source files put variable
related definitions into new include efi_variable.h instead of efi_loader.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-11 23:14:16 +02:00