[PATCH v3 2/3] efi_loader: efi_auth_var_type for AuditMode, DeployedMode

[Heinrich Schuchardt]

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 at canonical.com>
---
 include/efi_variable.h          | 1 +
 lib/efi_loader/efi_var_common.c | 2 ++
 lib/efi_loader/efi_variable.c   | 4 ++--
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/efi_variable.h b/include/efi_variable.h
index 2d97655e1f..0440d356bc 100644
--- a/include/efi_variable.h
+++ b/include/efi_variable.h
@@ -12,6 +12,7 @@
 
 enum efi_auth_var_type {
 	EFI_AUTH_VAR_NONE = 0,
+	EFI_AUTH_MODE,
 	EFI_AUTH_VAR_PK,
 	EFI_AUTH_VAR_KEK,
 	EFI_AUTH_VAR_DB,
diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
index 005c03ea5f..c744e2fd91 100644
--- a/lib/efi_loader/efi_var_common.c
+++ b/lib/efi_loader/efi_var_common.c
@@ -34,6 +34,8 @@ static const struct efi_auth_var_name_type name_type[] = {
 	{u"dbx",  &efi_guid_image_security_database, EFI_AUTH_VAR_DBX},
 	{u"dbt",  &efi_guid_image_security_database, EFI_AUTH_VAR_DBT},
 	{u"dbr",  &efi_guid_image_security_database, EFI_AUTH_VAR_DBR},
+	{u"AuditMode", &efi_global_variable_guid, EFI_AUTH_MODE},
+	{u"DeployedMode", &efi_global_variable_guid, EFI_AUTH_MODE},
 };
 
 static bool efi_secure_boot;
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index a7d305ffbc..fa2b6bc7a8 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -247,7 +247,7 @@ efi_status_t efi_set_variable_int(u16 *variable_name, const efi_guid_t *vendor,
 			return EFI_WRITE_PROTECTED;
 
 		if (IS_ENABLED(CONFIG_EFI_VARIABLES_PRESEED)) {
-			if (var_type != EFI_AUTH_VAR_NONE)
+			if (var_type >= EFI_AUTH_VAR_PK)
 				return EFI_WRITE_PROTECTED;
 		}
 
@@ -268,7 +268,7 @@ efi_status_t efi_set_variable_int(u16 *variable_name, const efi_guid_t *vendor,
 			return EFI_NOT_FOUND;
 	}
 
-	if (var_type != EFI_AUTH_VAR_NONE) {
+	if (var_type >= EFI_AUTH_VAR_PK) {
 		/* authentication is mandatory */
 		if (!(attributes &
 		      EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)) {
-- 
2.32.0