mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-16 09:48:16 +00:00
99bfab8b58
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>
322 lines
8.7 KiB
C
322 lines
8.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* UEFI runtime variable services
|
|
*
|
|
* Copyright (c) 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <efi_loader.h>
|
|
#include <efi_variable.h>
|
|
|
|
enum efi_secure_mode {
|
|
EFI_MODE_SETUP,
|
|
EFI_MODE_USER,
|
|
EFI_MODE_AUDIT,
|
|
EFI_MODE_DEPLOYED,
|
|
};
|
|
|
|
struct efi_auth_var_name_type {
|
|
const u16 *name;
|
|
const efi_guid_t *guid;
|
|
const enum efi_auth_var_type type;
|
|
};
|
|
|
|
static const struct efi_auth_var_name_type name_type[] = {
|
|
{u"PK", &efi_global_variable_guid, EFI_AUTH_VAR_PK},
|
|
{u"KEK", &efi_global_variable_guid, EFI_AUTH_VAR_KEK},
|
|
{u"db", &efi_guid_image_security_database, EFI_AUTH_VAR_DB},
|
|
{u"dbx", &efi_guid_image_security_database, EFI_AUTH_VAR_DBX},
|
|
/* not used yet
|
|
{u"dbt", &efi_guid_image_security_database, EFI_AUTH_VAR_DBT},
|
|
{u"dbr", &efi_guid_image_security_database, EFI_AUTH_VAR_DBR},
|
|
*/
|
|
};
|
|
|
|
static bool efi_secure_boot;
|
|
static enum efi_secure_mode efi_secure_mode;
|
|
|
|
/**
|
|
* efi_efi_get_variable() - retrieve value of a UEFI variable
|
|
*
|
|
* This function implements the GetVariable runtime service.
|
|
*
|
|
* See the Unified Extensible Firmware Interface (UEFI) specification for
|
|
* details.
|
|
*
|
|
* @variable_name: name of the variable
|
|
* @vendor: vendor GUID
|
|
* @attributes: attributes of the variable
|
|
* @data_size: size of the buffer to which the variable value is copied
|
|
* @data: buffer to which the variable value is copied
|
|
* Return: status code
|
|
*/
|
|
efi_status_t EFIAPI efi_get_variable(u16 *variable_name,
|
|
const efi_guid_t *vendor, u32 *attributes,
|
|
efi_uintn_t *data_size, void *data)
|
|
{
|
|
efi_status_t ret;
|
|
|
|
EFI_ENTRY("\"%ls\" %pUl %p %p %p", variable_name, vendor, attributes,
|
|
data_size, data);
|
|
|
|
ret = efi_get_variable_int(variable_name, vendor, attributes,
|
|
data_size, data, NULL);
|
|
|
|
/* Remove EFI_VARIABLE_READ_ONLY flag */
|
|
if (attributes)
|
|
*attributes &= EFI_VARIABLE_MASK;
|
|
|
|
return EFI_EXIT(ret);
|
|
}
|
|
|
|
/**
|
|
* efi_set_variable() - set value of a UEFI variable
|
|
*
|
|
* This function implements the SetVariable runtime service.
|
|
*
|
|
* See the Unified Extensible Firmware Interface (UEFI) specification for
|
|
* details.
|
|
*
|
|
* @variable_name: name of the variable
|
|
* @vendor: vendor GUID
|
|
* @attributes: attributes of the variable
|
|
* @data_size: size of the buffer with the variable value
|
|
* @data: buffer with the variable value
|
|
* Return: status code
|
|
*/
|
|
efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
|
|
const efi_guid_t *vendor, u32 attributes,
|
|
efi_uintn_t data_size, const void *data)
|
|
{
|
|
efi_status_t ret;
|
|
|
|
EFI_ENTRY("\"%ls\" %pUl %x %zu %p", variable_name, vendor, attributes,
|
|
data_size, data);
|
|
|
|
/* Make sure that the EFI_VARIABLE_READ_ONLY flag is not set */
|
|
if (attributes & ~(u32)EFI_VARIABLE_MASK)
|
|
ret = EFI_INVALID_PARAMETER;
|
|
else
|
|
ret = efi_set_variable_int(variable_name, vendor, attributes,
|
|
data_size, data, true);
|
|
|
|
return EFI_EXIT(ret);
|
|
}
|
|
|
|
/**
|
|
* efi_get_next_variable_name() - enumerate the current variable names
|
|
*
|
|
* @variable_name_size: size of variable_name buffer in byte
|
|
* @variable_name: name of uefi variable's name in u16
|
|
* @vendor: vendor's guid
|
|
*
|
|
* See the Unified Extensible Firmware Interface (UEFI) specification for
|
|
* details.
|
|
*
|
|
* Return: status code
|
|
*/
|
|
efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
|
|
u16 *variable_name,
|
|
efi_guid_t *vendor)
|
|
{
|
|
efi_status_t ret;
|
|
|
|
EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, vendor);
|
|
|
|
ret = efi_get_next_variable_name_int(variable_name_size, variable_name,
|
|
vendor);
|
|
|
|
return EFI_EXIT(ret);
|
|
}
|
|
|
|
/**
|
|
* efi_query_variable_info() - get information about EFI variables
|
|
*
|
|
* This function implements the QueryVariableInfo() runtime service.
|
|
*
|
|
* See the Unified Extensible Firmware Interface (UEFI) specification for
|
|
* details.
|
|
*
|
|
* @attributes: bitmask to select variables to be
|
|
* queried
|
|
* @maximum_variable_storage_size: maximum size of storage area for the
|
|
* selected variable types
|
|
* @remaining_variable_storage_size: remaining size of storage are for the
|
|
* selected variable types
|
|
* @maximum_variable_size: maximum size of a variable of the
|
|
* selected type
|
|
* Returns: status code
|
|
*/
|
|
efi_status_t EFIAPI efi_query_variable_info(
|
|
u32 attributes, u64 *maximum_variable_storage_size,
|
|
u64 *remaining_variable_storage_size,
|
|
u64 *maximum_variable_size)
|
|
{
|
|
efi_status_t ret;
|
|
|
|
EFI_ENTRY("%x %p %p %p", attributes, maximum_variable_storage_size,
|
|
remaining_variable_storage_size, maximum_variable_size);
|
|
|
|
ret = efi_query_variable_info_int(attributes,
|
|
maximum_variable_storage_size,
|
|
remaining_variable_storage_size,
|
|
maximum_variable_size);
|
|
|
|
return EFI_EXIT(ret);
|
|
}
|
|
|
|
/**
|
|
* efi_set_secure_state - modify secure boot state variables
|
|
* @secure_boot: value of SecureBoot
|
|
* @setup_mode: value of SetupMode
|
|
* @audit_mode: value of AuditMode
|
|
* @deployed_mode: value of DeployedMode
|
|
*
|
|
* Modify secure boot status related variables as indicated.
|
|
*
|
|
* Return: status code
|
|
*/
|
|
static efi_status_t efi_set_secure_state(u8 secure_boot, u8 setup_mode,
|
|
u8 audit_mode, u8 deployed_mode)
|
|
{
|
|
efi_status_t ret;
|
|
const u32 attributes_ro = EFI_VARIABLE_BOOTSERVICE_ACCESS |
|
|
EFI_VARIABLE_RUNTIME_ACCESS |
|
|
EFI_VARIABLE_READ_ONLY;
|
|
const u32 attributes_rw = EFI_VARIABLE_BOOTSERVICE_ACCESS |
|
|
EFI_VARIABLE_RUNTIME_ACCESS;
|
|
|
|
efi_secure_boot = secure_boot;
|
|
|
|
ret = efi_set_variable_int(L"SecureBoot", &efi_global_variable_guid,
|
|
attributes_ro, sizeof(secure_boot),
|
|
&secure_boot, false);
|
|
if (ret != EFI_SUCCESS)
|
|
goto err;
|
|
|
|
ret = efi_set_variable_int(L"SetupMode", &efi_global_variable_guid,
|
|
attributes_ro, sizeof(setup_mode),
|
|
&setup_mode, false);
|
|
if (ret != EFI_SUCCESS)
|
|
goto err;
|
|
|
|
ret = efi_set_variable_int(L"AuditMode", &efi_global_variable_guid,
|
|
audit_mode || setup_mode ?
|
|
attributes_ro : attributes_rw,
|
|
sizeof(audit_mode), &audit_mode, false);
|
|
if (ret != EFI_SUCCESS)
|
|
goto err;
|
|
|
|
ret = efi_set_variable_int(L"DeployedMode",
|
|
&efi_global_variable_guid,
|
|
audit_mode || deployed_mode || setup_mode ?
|
|
attributes_ro : attributes_rw,
|
|
sizeof(deployed_mode), &deployed_mode,
|
|
false);
|
|
err:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* efi_transfer_secure_state - handle a secure boot state transition
|
|
* @mode: new state
|
|
*
|
|
* Depending on @mode, secure boot related variables are updated.
|
|
* Those variables are *read-only* for users, efi_set_variable_int()
|
|
* is called here.
|
|
*
|
|
* Return: status code
|
|
*/
|
|
static efi_status_t efi_transfer_secure_state(enum efi_secure_mode mode)
|
|
{
|
|
efi_status_t ret;
|
|
|
|
EFI_PRINT("Switching secure state from %d to %d\n", efi_secure_mode,
|
|
mode);
|
|
|
|
if (mode == EFI_MODE_DEPLOYED) {
|
|
ret = efi_set_secure_state(1, 0, 0, 1);
|
|
if (ret != EFI_SUCCESS)
|
|
goto err;
|
|
} else if (mode == EFI_MODE_AUDIT) {
|
|
ret = efi_set_variable_int(L"PK", &efi_global_variable_guid,
|
|
EFI_VARIABLE_BOOTSERVICE_ACCESS |
|
|
EFI_VARIABLE_RUNTIME_ACCESS,
|
|
0, NULL, false);
|
|
if (ret != EFI_SUCCESS)
|
|
goto err;
|
|
|
|
ret = efi_set_secure_state(0, 1, 1, 0);
|
|
if (ret != EFI_SUCCESS)
|
|
goto err;
|
|
} else if (mode == EFI_MODE_USER) {
|
|
ret = efi_set_secure_state(1, 0, 0, 0);
|
|
if (ret != EFI_SUCCESS)
|
|
goto err;
|
|
} else if (mode == EFI_MODE_SETUP) {
|
|
ret = efi_set_secure_state(0, 1, 0, 0);
|
|
if (ret != EFI_SUCCESS)
|
|
goto err;
|
|
} else {
|
|
return EFI_INVALID_PARAMETER;
|
|
}
|
|
|
|
efi_secure_mode = mode;
|
|
|
|
return EFI_SUCCESS;
|
|
|
|
err:
|
|
/* TODO: What action should be taken here? */
|
|
printf("ERROR: Secure state transition failed\n");
|
|
return ret;
|
|
}
|
|
|
|
efi_status_t efi_init_secure_state(void)
|
|
{
|
|
enum efi_secure_mode mode = EFI_MODE_SETUP;
|
|
u8 efi_vendor_keys = 0;
|
|
efi_uintn_t size = 0;
|
|
efi_status_t ret;
|
|
|
|
ret = efi_get_variable_int(L"PK", &efi_global_variable_guid,
|
|
NULL, &size, NULL, NULL);
|
|
if (ret == EFI_BUFFER_TOO_SMALL) {
|
|
if (IS_ENABLED(CONFIG_EFI_SECURE_BOOT))
|
|
mode = EFI_MODE_USER;
|
|
}
|
|
|
|
ret = efi_transfer_secure_state(mode);
|
|
if (ret != EFI_SUCCESS)
|
|
return ret;
|
|
|
|
/* As we do not provide vendor keys this variable is always 0. */
|
|
ret = efi_set_variable_int(L"VendorKeys",
|
|
&efi_global_variable_guid,
|
|
EFI_VARIABLE_BOOTSERVICE_ACCESS |
|
|
EFI_VARIABLE_RUNTIME_ACCESS |
|
|
EFI_VARIABLE_READ_ONLY,
|
|
sizeof(efi_vendor_keys),
|
|
&efi_vendor_keys, false);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* efi_secure_boot_enabled - return if secure boot is enabled or not
|
|
*
|
|
* Return: true if enabled, false if disabled
|
|
*/
|
|
bool efi_secure_boot_enabled(void)
|
|
{
|
|
return efi_secure_boot;
|
|
}
|
|
|
|
enum efi_auth_var_type efi_auth_var_get_type(u16 *name, const efi_guid_t *guid)
|
|
{
|
|
for (size_t i = 0; i < ARRAY_SIZE(name_type); ++i) {
|
|
if (!u16_strcmp(name, name_type[i].name) &&
|
|
!guidcmp(guid, name_type[i].guid))
|
|
return name_type[i].type;
|
|
}
|
|
return EFI_AUTH_VAR_NONE;
|
|
}
|