efi_loader: simplify tcg2_measure_secure_boot_variable()

This commit simplifies tcg2_measure_secure_boot_variable()
using secure_variables table.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>

diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index dc45eaf..d1ccd8e 100644 (file)
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -81,12 +81,19 @@ static const struct digest_info hash_algo_list[] = {
        },
 };
 
-static const u16 *secure_variables[] = {
-       u"SecureBoot",
-       u"PK",
-       u"KEK",
-       u"db",
-       u"dbx",
+struct variable_info {
+       const u16       *name;
+       bool            accept_empty;
+};
+
+static struct variable_info secure_variables[] = {
+       {u"SecureBoot",         true},
+       {u"PK",                 true},
+       {u"KEK",                true},
+       {u"db",                 true},
+       {u"dbx",                true},
+       {u"dbt",                false},
+       {u"dbr",                false},
 };
 
 #define MAX_HASH_COUNT ARRAY_SIZE(hash_algo_list)
@@ -1820,52 +1827,21 @@ static efi_status_t tcg2_measure_secure_boot_variable(struct udevice *dev)
        for (i = 0; i < count; i++) {
                const efi_guid_t *guid;
 
-               guid = efi_auth_var_get_guid(secure_variables[i]);
+               guid = efi_auth_var_get_guid(secure_variables[i].name);
 
-               /*
-                * According to the TCG2 PC Client PFP spec, "SecureBoot",
-                * "PK", "KEK", "db" and "dbx" variables must be measured
-                * even if they are empty.
-                */
-               data = efi_get_var(secure_variables[i], guid, &data_size);
+               data = efi_get_var(secure_variables[i].name, guid, &data_size);
+               if (!data && !secure_variables[i].accept_empty)
+                       continue;
 
                ret = tcg2_measure_variable(dev, 7,
                                            EV_EFI_VARIABLE_DRIVER_CONFIG,
-                                           secure_variables[i], guid,
+                                           secure_variables[i].name, guid,
                                            data_size, data);
                free(data);
                if (ret != EFI_SUCCESS)
                        goto error;
        }
 
-       /*
-        * TCG2 PC Client PFP spec says "dbt" and "dbr" are
-        * measured if present and not empty.
-        */
-       data = efi_get_var(L"dbt",
-                          &efi_guid_image_security_database,
-                          &data_size);
-       if (data) {
-               ret = tcg2_measure_variable(dev, 7,
-                                           EV_EFI_VARIABLE_DRIVER_CONFIG,
-                                           L"dbt",
-                                           &efi_guid_image_security_database,
-                                           data_size, data);
-               free(data);
-       }
-
-       data = efi_get_var(L"dbr",
-                          &efi_guid_image_security_database,
-                          &data_size);
-       if (data) {
-               ret = tcg2_measure_variable(dev, 7,
-                                           EV_EFI_VARIABLE_DRIVER_CONFIG,
-                                           L"dbr",
-                                           &efi_guid_image_security_database,
-                                           data_size, data);
-               free(data);
-       }
-
 error:
        return ret;
 }