[PATCH v2 19/21] appendedsig: Reads the default DB keys from ELF Note

[Sudhakar Kuppusamy]

If Secure Boot is enabled with PKS and the use_static_keys flag is set,
then read the DB default keys from the ELF note and store them in the trusted 
list buffer.

Signed-off-by: Sudhakar Kuppusamy <sudha...@linux.ibm.com>
Reviewed-by: Stefan Berger <stef...@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avn...@linux.ibm.com>
---
 grub-core/commands/appendedsig/appendedsig.c | 56 ++++++++++++++------
 1 file changed, 40 insertions(+), 16 deletions(-)

diff --git a/grub-core/commands/appendedsig/appendedsig.c 
b/grub-core/commands/appendedsig/appendedsig.c
index 3abb45ae0..5631f0ab4 100644
--- a/grub-core/commands/appendedsig/appendedsig.c
+++ b/grub-core/commands/appendedsig/appendedsig.c
@@ -1041,7 +1041,7 @@ create_distrusted_list (void)
  * parse it, and add it to the trusted list.
  */
 static grub_err_t
-build_static_trusted_list (const struct grub_module_header *header)
+build_static_trusted_list (const struct grub_module_header *header, const 
grub_bool_t is_pks)
 {
   grub_err_t err = GRUB_ERR_NONE;
   struct grub_file pseudo_file;
@@ -1060,6 +1060,13 @@ build_static_trusted_list (const struct 
grub_module_header *header)
   if (err != GRUB_ERR_NONE)
     return err;
 
+  if (is_pks)
+    {
+      err = is_distrusted_cert_hash (cert_data, cert_data_size);
+      if (err != GRUB_ERR_NONE)
+        return err;
+    }
+
   err = add_certificate (cert_data, cert_data_size, &db, 1);
   grub_free (cert_data);
 
@@ -1112,6 +1119,22 @@ free_distrusted_list (void)
   grub_memset (&dbx, 0, sizeof (dbx));
 }
 
+static grub_err_t
+load_static_keys (const struct grub_module_header *header, const grub_bool_t 
is_pks)
+{
+  int rc = GRUB_ERR_NONE;
+  FOR_MODULES (header)
+    {
+      /* Not an ELF module, skip.  */
+      if (header->type != OBJ_TYPE_X509_PUBKEY)
+        continue;
+      rc = build_static_trusted_list (header, is_pks);
+      if (rc != GRUB_ERR_NONE)
+        return rc;
+    }
+  return rc;
+}
+
 GRUB_MOD_INIT (appendedsig)
 {
   int rc;
@@ -1130,26 +1153,27 @@ GRUB_MOD_INIT (appendedsig)
 
   if (!grub_pks_use_keystore && check_sigs == check_sigs_forced)
     {
-      FOR_MODULES (header)
+      rc = load_static_keys (header, false);
+      if (rc != GRUB_ERR_NONE)
         {
-          /* Not an ELF module, skip.  */
-          if (header->type != OBJ_TYPE_X509_PUBKEY)
-            continue;
-
-          rc = build_static_trusted_list (header);
-          if (rc != GRUB_ERR_NONE)
-            {
-              free_trusted_list ();
-              grub_error (rc, "static trusted list creation failed");
-            }
-          else
-            grub_dprintf ("appendedsig", "the trusted list now has %" 
PRIuGRUB_SIZE " static keys\n",
-                          db.key_entries);
+          free_trusted_list ();
+          grub_error (rc, "static trusted list creation failed");
         }
+      else
+        grub_dprintf ("appendedsig", "the trusted list now has %" 
PRIuGRUB_SIZE " static keys\n",
+                      db.key_entries);
     }
   else if (grub_pks_use_keystore && check_sigs == check_sigs_forced)
     {
-      rc = create_trusted_list ();
+      if (grub_pks_keystore.use_static_keys)
+        {
+          grub_printf ("Warning: db variable is not available at PKS and using 
a static keys "
+                       "as a default key in trusted list\n");
+          rc = load_static_keys (header, grub_pks_keystore.use_static_keys);
+        }
+      else
+        rc = create_trusted_list ();
+
       if (rc != GRUB_ERR_NONE)
         {
           free_trusted_list ();
-- 
2.43.5


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