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From a4440ad8ead4131f20cc0671a2936ee03a85c284 Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@fedoraproject.org>
Date: Thu, 3 Oct 2013 10:14:23 -0400
Subject: [PATCH] MODSIGN: Support not importing certs from db
If a user tells shim to not use the certs/hashes in the UEFI db variable
for verification purposes, shim will set a UEFI variable called MokIgnoreDB.
Have the uefi import code look for this and not import things from the db
variable.
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
---
kernel/modsign_uefi.c | 40 +++++++++++++++++++++++++++++++---------
1 file changed, 31 insertions(+), 9 deletions(-)
diff --git a/kernel/modsign_uefi.c b/kernel/modsign_uefi.c
index 94b0eb38a284..ae28b974d49a 100644
--- a/kernel/modsign_uefi.c
+++ b/kernel/modsign_uefi.c
@@ -8,6 +8,23 @@
#include <keys/system_keyring.h>
#include "module-internal.h"
+static __init int check_ignore_db(void)
+{
+ efi_status_t status;
+ unsigned int db = 0;
+ unsigned long size = sizeof(db);
+ efi_guid_t guid = EFI_SHIM_LOCK_GUID;
+
+ /* Check and see if the MokIgnoreDB variable exists. If that fails
+ * then we don't ignore DB. If it succeeds, we do.
+ */
+ status = efi.get_variable(L"MokIgnoreDB", &guid, NULL, &size, &db);
+ if (status != EFI_SUCCESS)
+ return 0;
+
+ return 1;
+}
+
static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, unsigned long *size)
{
efi_status_t status;
@@ -47,23 +64,28 @@ static int __init load_uefi_certs(void)
efi_guid_t mok_var = EFI_SHIM_LOCK_GUID;
void *db = NULL, *dbx = NULL, *mok = NULL;
unsigned long dbsize = 0, dbxsize = 0, moksize = 0;
- int rc = 0;
+ int ignore_db, rc = 0;
/* Check if SB is enabled and just return if not */
if (!efi_enabled(EFI_SECURE_BOOT))
return 0;
+ /* See if the user has setup Ignore DB mode */
+ ignore_db = check_ignore_db();
+
/* Get db, MokListRT, and dbx. They might not exist, so it isn't
* an error if we can't get them.
*/
- db = get_cert_list(L"db", &secure_var, &dbsize);
- if (!db) {
- pr_err("MODSIGN: Couldn't get UEFI db list\n");
- } else {
- rc = parse_efi_signature_list(db, dbsize, system_trusted_keyring);
- if (rc)
- pr_err("Couldn't parse db signatures: %d\n", rc);
- kfree(db);
+ if (!ignore_db) {
+ db = get_cert_list(L"db", &secure_var, &dbsize);
+ if (!db) {
+ pr_err("MODSIGN: Couldn't get UEFI db list\n");
+ } else {
+ rc = parse_efi_signature_list(db, dbsize, system_trusted_keyring);
+ if (rc)
+ pr_err("Couldn't parse db signatures: %d\n", rc);
+ kfree(db);
+ }
}
mok = get_cert_list(L"MokListRT", &mok_var, &moksize);
--
1.9.3
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