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>
This commit is contained in:
Heinrich Schuchardt 2020-07-14 08:04:49 +02:00
parent f96744b250
commit 012c56ac76
3 changed files with 162 additions and 159 deletions

View File

@ -195,4 +195,11 @@ efi_status_t efi_var_mem_ins(u16 *variable_name,
*/
u64 efi_var_mem_free(void);
/**
* efi_init_secure_state - initialize secure boot state
*
* Return: status code
*/
efi_status_t efi_init_secure_state(void);
#endif

View File

@ -9,6 +9,16 @@
#include <efi_loader.h>
#include <efi_variable.h>
enum efi_secure_mode {
EFI_MODE_SETUP,
EFI_MODE_USER,
EFI_MODE_AUDIT,
EFI_MODE_DEPLOYED,
};
static bool efi_secure_boot;
static enum efi_secure_mode efi_secure_mode;
/**
* efi_efi_get_variable() - retrieve value of a UEFI variable
*
@ -138,3 +148,148 @@ efi_status_t EFIAPI efi_query_variable_info(
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;
}

View File

@ -19,165 +19,6 @@
#include <linux/compat.h>
#include <u-boot/crc.h>
enum efi_secure_mode {
EFI_MODE_SETUP,
EFI_MODE_USER,
EFI_MODE_AUDIT,
EFI_MODE_DEPLOYED,
};
static bool efi_secure_boot;
static enum efi_secure_mode efi_secure_mode;
static u8 efi_vendor_keys;
/**
* 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_init_secure_state - initialize secure boot state
*
* Return: status code
*/
static efi_status_t efi_init_secure_state(void)
{
enum efi_secure_mode mode = EFI_MODE_SETUP;
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;
}
#ifdef CONFIG_EFI_SECURE_BOOT
static u8 pkcs7_hdr[] = {