[PATCH v2 01/16] PM / hibernate: define HMAC algorithm and digest size of hibernation

Lee, Chun-Yi
2015-08-11T06:17:37Z

Using HMAC-SHA1 to be the HMAC algorithm of signing hibernate
snapshot image. The digest size of HMAC-SHA1 is 160 bits (20 bytes),
this size will be also applied to the length of HMAC key.

In addition, moved swsusp_info struct definition into CONFIG_HIBERNATION
ifdef block because only hibernate code uses it.
Add HIBERNATE_VERIFICATION kernel config for using by later hibernate
signature verification code.

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
---
include/linux/suspend.h | 5 +++++
kernel/power/Kconfig | 13 +++++++++++++
kernel/power/power.h | 3 ++-
3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 5efe743..56c6de9 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -327,6 +327,11 @@ struct platform_hibernation_ops {
};

#ifdef CONFIG_HIBERNATION
+
+/* HMAC Algorithm of Hibernate Signature */
+#define HIBERNATION_HMAC "hmac(sha1)"
+#define HIBERNATION_DIGEST_SIZE 20
+
/* kernel/power/snapshot.c */
extern void __register_nosave_region(unsigned long b, unsigned long e, int km);
static inline void __init register_nosave_region(unsigned long b, unsigned long e)
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 9e30231..8608b3b 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -66,6 +66,19 @@ config HIBERNATION

For more information take a look at <file:Documentation/power/swsusp.txt>.

+config HIBERNATE_VERIFICATION
+ bool "Hibernate verification"
+ depends on HIBERNATION
+ depends on EFI_STUB
+ depends on X86
+ select CRYPTO_HMAC
+ select CRYPTO_SHA1
+ help
+ This option provides support for generating and verifying the
+ signature of memory snapshot image by HMAC-SHA1. Current mechanism
+ relies on UEFI secure boot environment, EFI stub generates HMAC
+ key for hibernate verification.
+
config ARCH_SAVE_PAGE_KEYS
bool

diff --git a/kernel/power/power.h b/kernel/power/power.h
index caadb56..6ea5c78 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -4,6 +4,7 @@
#include <linux/freezer.h>
#include <linux/compiler.h>

+#ifdef CONFIG_HIBERNATION
struct swsusp_info {
struct new_utsname uts;
u32 version_code;
@@ -12,9 +13,9 @@ struct swsusp_info {
unsigned long image_pages;
unsigned long pages;
unsigned long size;
+ u8 signature[HIBERNATION_DIGEST_SIZE];
} __aligned(PAGE_SIZE);

-#ifdef CONFIG_HIBERNATION
/* kernel/power/snapshot.c */
extern void __init hibernate_reserved_size_init(void);
extern void __init hibernate_image_size_init(void);
--
2.1.4