grub2/grub-2.00-who-trusts-you-and-who-do-you-trust.patch

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2012-06-28 18:50:33 +00:00
From 44cee23d139fe8faaca2622cc09041b1d684265b Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Tue, 5 Jun 2012 09:23:25 -0400
Subject: [PATCH] Support secure boot.
If SecureBoot is enabled, treat all authentications as failure, and also
use shim's verify routine to verify the kernel before loading.
---
grub-core/loader/i386/linux.c | 26 +++++++++++++
grub-core/normal/auth.c | 85 +++++++++++++++++++++++++++++++++++++++++
grub-core/normal/main.c | 4 +-
grub-core/normal/menu_entry.c | 5 ++-
include/grub/auth.h | 3 ++
5 files changed, 121 insertions(+), 2 deletions(-)
diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c
index 6e8238e..090484c 100644
--- a/grub-core/loader/i386/linux.c
+++ b/grub-core/loader/i386/linux.c
@@ -34,6 +34,7 @@
#include <grub/i386/relocator.h>
#include <grub/i18n.h>
#include <grub/lib/cmdline.h>
+#include <grub/auth.h>
GRUB_MOD_LICENSE ("GPLv3+");
@@ -681,6 +682,9 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
int relocatable;
grub_uint64_t preffered_address = GRUB_LINUX_BZIMAGE_ADDR;
+ void *buffer;
+ grub_err_t verified;
+
grub_dl_ref (my_mod);
if (argc == 0)
@@ -693,6 +697,28 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
if (! file)
goto fail;
+ buffer = grub_malloc(grub_file_size(file));
+ if (!buffer)
+ return grub_errno;
+
+ if (grub_file_read (file, buffer, grub_file_size(file)))
+ {
+ if (!grub_errno)
+ grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
+ argv[0]);
+ goto fail;
+ }
+
+ verified = grub_auth_verify_signature(buffer, grub_file_size(file));
+ grub_free(buffer);
+ if (verified != GRUB_ERR_NONE)
+ {
+ grub_errno = verified;
+ goto fail;
+ }
+
+ grub_free(buffer);
+ grub_file_seek(file, 0);
if (grub_file_read (file, &lh, sizeof (lh)) != sizeof (lh))
{
if (!grub_errno)
diff --git a/grub-core/normal/auth.c b/grub-core/normal/auth.c
index c6bd96e..3e83ee8 100644
--- a/grub-core/normal/auth.c
+++ b/grub-core/normal/auth.c
@@ -24,6 +24,8 @@
#include <grub/normal.h>
#include <grub/time.h>
#include <grub/i18n.h>
+#include <grub/efi/api.h>
+#include <grub/efi/efi.h>
struct grub_auth_user
{
@@ -198,6 +200,89 @@ grub_username_get (char buf[], unsigned buf_size)
}
grub_err_t
+grub_auth_secure_boot (void)
+{
+#ifdef GRUB_MACHINE_EFI
+ grub_size_t datasize = 0;
+ grub_uint8_t *data;
+ grub_efi_guid_t guid = GRUB_EFI_GLOBAL_VARIABLE_GUID;
+ unsigned int x;
+
2012-07-14 16:10:40 +00:00
+ data = grub_efi_get_variable ("SecureBoot", &guid, &datasize);
2012-06-28 18:50:33 +00:00
+ if (!data)
+ return GRUB_ERR_NONE;
+
+ for (x = 0; x < datasize; x++)
+ if (data[x] == 1)
+ return GRUB_ACCESS_DENIED;
+#endif
+
+ return GRUB_ERR_NONE;
+}
+
+int
+grub_is_secure_boot (void)
+{
+ return grub_auth_secure_boot() == GRUB_ACCESS_DENIED;
+}
+
+#define SHIM_LOCK_GUID \
+ { 0x605dab50, 0xe046, 0x4300, {0xab,0xb6,0x3d,0xd8,0x10,0xdd,0x8b,0x23} }
+
+typedef grub_efi_status_t (*EFI_SHIM_LOCK_VERIFY)(void *buffer, grub_efi_uint32_t size);
+
+typedef struct _SHIM_LOCK {
+ EFI_SHIM_LOCK_VERIFY Verify;
+} SHIM_LOCK;
+
+grub_err_t
+grub_auth_verify_signature (void *buffer, grub_uint32_t size)
+{
+#ifdef GRUB_MACHINE_EFI
+ grub_efi_guid_t shim_guid = SHIM_LOCK_GUID;
+ SHIM_LOCK *shim = NULL;
+ grub_efi_handle_t *handles, shim_handle = NULL;
+ grub_efi_uintn_t num_handles, i;
+ grub_efi_status_t status;
+
+ if (!grub_is_secure_boot())
+ return GRUB_ERR_NONE;
+
+ handles = grub_efi_locate_handle (GRUB_EFI_BY_PROTOCOL, &shim_guid, NULL,
+ &num_handles);
+ if (!handles || num_handles == 0)
+no_verify:
+ return grub_error (GRUB_ACCESS_DENIED, "Could not find signature verification routine");
+
+ for (i = 0; i < num_handles; i++)
+ {
+ shim_handle = handles[i];
+ shim = grub_efi_open_protocol (shim_handle, &shim_guid,
+ GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+ if (shim)
+ break;
+ }
+
+ if (!shim)
+ {
+ grub_free(handles);
+ goto no_verify;
+ }
+
+ status = shim->Verify(buffer, size);
+
+ grub_free(handles);
+
+ if (status == GRUB_EFI_SUCCESS)
+ return GRUB_ERR_NONE;
+
+ return grub_error (GRUB_ACCESS_DENIED, "Signature verification failed");
+#else
+ return GRUB_ERR_NONE;
+#endif
+}
+
+grub_err_t
grub_auth_check_authentication (const char *userlist)
{
char login[1024];
diff --git a/grub-core/normal/main.c b/grub-core/normal/main.c
index 193d7d3..1e321a4 100644
--- a/grub-core/normal/main.c
+++ b/grub-core/normal/main.c
@@ -455,7 +455,9 @@ grub_cmdline_run (int nested)
{
grub_err_t err = GRUB_ERR_NONE;
- err = grub_auth_check_authentication (NULL);
+ err = grub_auth_secure_boot ();
+ if (err == GRUB_ERR_NONE)
+ err = grub_auth_check_authentication (NULL);
if (err)
{
diff --git a/grub-core/normal/menu_entry.c b/grub-core/normal/menu_entry.c
index 7fc890d..4e7a08c 100644
--- a/grub-core/normal/menu_entry.c
+++ b/grub-core/normal/menu_entry.c
@@ -1287,7 +1287,10 @@ grub_menu_entry_run (grub_menu_entry_t entry)
unsigned i;
grub_term_output_t term;
- err = grub_auth_check_authentication (NULL);
+
+ err = grub_auth_secure_boot ();
+ if (err == GRUB_ERR_NONE)
+ err = grub_auth_check_authentication (NULL);
if (err)
{
diff --git a/include/grub/auth.h b/include/grub/auth.h
index 7473344..b933fa1 100644
--- a/include/grub/auth.h
+++ b/include/grub/auth.h
@@ -32,6 +32,9 @@ grub_err_t grub_auth_unregister_authentication (const char *user);
grub_err_t grub_auth_authenticate (const char *user);
grub_err_t grub_auth_deauthenticate (const char *user);
+grub_err_t grub_auth_secure_boot (void);
+int grub_is_secure_boot (void);
+grub_err_t grub_auth_verify_signature (void *buffer, grub_uint32_t size);
grub_err_t grub_auth_check_authentication (const char *userlist);
#endif /* ! GRUB_AUTH_HEADER */
--
1.7.10.2