The capsule signature is now part of our DTB. This is problematic when a
user is allowed to change/fixup that DTB from U-Boots command line since he
can overwrite the signature as well.
So Instead of adding the key on the DTB, embed it in the u-boot binary it
self as part of it's .rodata. This assumes that the U-Boot binary we load
is authenticated by a previous boot stage loader.
Reviewed-by: Masami Hiramatsu <masami.hiramatsu at linaro.org>
Tested-by: Masami Hiramatsu <masami.hiramatsu at linaro.org>
Tested-by: Sughosh Ganu <sughosh.ganu at linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
changes since v1:
- added static keyword on efi_get_public_key_data()
- added missing config.h on efi_capsule_key.S
board/emulation/common/Makefile | 1 -
board/emulation/common/qemu_capsule.c | 43 ---------------------------
include/asm-generic/sections.h | 2 ++
lib/efi_loader/Kconfig | 7 +++++
lib/efi_loader/Makefile | 8 +++++
lib/efi_loader/efi_capsule.c | 18 +++++++++--
lib/efi_loader/efi_capsule_key.S | 17 +++++++++++
7 files changed, 49 insertions(+), 47 deletions(-)
delete mode 100644 board/emulation/common/qemu_capsule.c
create mode 100644 lib/efi_loader/efi_capsule_key.S
diff --git a/board/emulation/common/Makefile b/board/emulation/common/Makefile
index 7ed447a69dce..c5b452e7e341 100644
--- a/board/emulation/common/Makefile
+++ b/board/emulation/common/Makefile
@@ -2,4 +2,3 @@
obj-$(CONFIG_SYS_MTDPARTS_RUNTIME) += qemu_mtdparts.o
obj-$(CONFIG_SET_DFU_ALT_INFO) += qemu_dfu.o
-obj-$(CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT) += qemu_capsule.o
diff --git a/board/emulation/common/qemu_capsule.c b/board/emulation/common/qemu_capsule.c
deleted file mode 100644
index 6b8a87022a4c..000000000000
--- a/board/emulation/common/qemu_capsule.c
+++ /dev/null
@@ -1,43 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Copyright (c) 2020 Linaro Limited
- */
-
-#include <common.h>
-#include <efi_api.h>
-#include <efi_loader.h>
-#include <env.h>
-#include <fdtdec.h>
-#include <asm/global_data.h>
-
-DECLARE_GLOBAL_DATA_PTR;
-
-int efi_get_public_key_data(void **pkey, efi_uintn_t *pkey_len)
-{
- const void *fdt_blob = gd->fdt_blob;
- const void *blob;
- const char *cnode_name = "capsule-key";
- const char *snode_name = "signature";
- int sig_node;
- int len;
-
- sig_node = fdt_subnode_offset(fdt_blob, 0, snode_name);
- if (sig_node < 0) {
- EFI_PRINT("Unable to get signature node offset\n");
- return -FDT_ERR_NOTFOUND;
- }
-
- blob = fdt_getprop(fdt_blob, sig_node, cnode_name, &len);
-
- if (!blob || len < 0) {
- EFI_PRINT("Unable to get capsule-key value\n");
- *pkey = NULL;
- *pkey_len = 0;
- return -FDT_ERR_NOTFOUND;
- }
-
- *pkey = (void *)blob;
- *pkey_len = len;
-
- return 0;
-}
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 267f1db73f23..ec992b0c2e3f 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -27,6 +27,8 @@ extern char __efi_helloworld_begin[];
extern char __efi_helloworld_end[];
extern char __efi_var_file_begin[];
extern char __efi_var_file_end[];
+extern char __efi_capsule_sig_begin[];
+extern char __efi_capsule_sig_end[];
/* Private data used by of-platdata devices/uclasses */
extern char __priv_data_start[], __priv_data_end[];
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index 156b39152112..cf6ff2d537f4 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -213,6 +213,13 @@ config EFI_CAPSULE_AUTHENTICATE
Select this option if you want to enable capsule
authentication
+config EFI_CAPSULE_KEY_PATH
+ string "Path to .esl cert for capsule authentication"
+ depends on EFI_CAPSULE_AUTHENTICATE
+ help
+ Provide the EFI signature list (esl) certificate used for capsule
+ authentication
+
config EFI_DEVICE_PATH_TO_TEXT
bool "Device path to text protocol"
default y
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index fd344cea29b0..9b369430e258 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -20,11 +20,19 @@ always += helloworld.efi
targets += helloworld.o
endif
+ifeq ($(CONFIG_EFI_CAPSULE_AUTHENTICATE),y)
+EFI_CAPSULE_KEY_PATH := $(subst $\",,$(CONFIG_EFI_CAPSULE_KEY_PATH))
+ifeq ("$(wildcard $(EFI_CAPSULE_KEY_PATH))","")
+$(error .esl cerificate not found. Configure your CONFIG_EFI_CAPSULE_KEY_PATH)
+endif
+endif
+
obj-$(CONFIG_CMD_BOOTEFI_HELLO) += helloworld_efi.o
obj-$(CONFIG_CMD_BOOTEFI_BOOTMGR) += efi_bootmgr.o
obj-y += efi_boottime.o
obj-y += efi_helper.o
obj-$(CONFIG_EFI_HAVE_CAPSULE_SUPPORT) += efi_capsule.o
+obj-$(CONFIG_EFI_CAPSULE_AUTHENTICATE) += efi_capsule_key.o
obj-$(CONFIG_EFI_CAPSULE_FIRMWARE) += efi_firmware.o
obj-y += efi_console.o
obj-y += efi_device_path.o
diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
index b878e71438b8..1900a938c140 100644
--- a/lib/efi_loader/efi_capsule.c
+++ b/lib/efi_loader/efi_capsule.c
@@ -16,6 +16,7 @@
#include <mapmem.h>
#include <sort.h>
+#include <asm/sections.h>
#include <crypto/pkcs7.h>
#include <crypto/pkcs7_parser.h>
#include <linux/err.h>
@@ -222,12 +223,23 @@ skip:
const efi_guid_t efi_guid_capsule_root_cert_guid =
EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID;
+static int efi_get_public_key_data(void **pkey, efi_uintn_t *pkey_len)
+{
+ const void *blob = __efi_capsule_sig_begin;
+ const int len = __efi_capsule_sig_end - __efi_capsule_sig_begin;
+
+ *pkey = (void *)blob;
+ *pkey_len = len;
+
+ return 0;
+}
+
efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_size,
void **image, efi_uintn_t *image_size)
{
u8 *buf;
int ret;
- void *fdt_pkey, *pkey;
+ void *stored_pkey, *pkey;
efi_uintn_t pkey_len;
uint64_t monotonic_count;
struct efi_signature_store *truststore;
@@ -286,7 +298,7 @@ efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_s
goto out;
}
- ret = efi_get_public_key_data(&fdt_pkey, &pkey_len);
+ ret = efi_get_public_key_data(&stored_pkey, &pkey_len);
if (ret < 0)
goto out;
@@ -294,7 +306,7 @@ efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_s
if (!pkey)
goto out;
- memcpy(pkey, fdt_pkey, pkey_len);
+ memcpy(pkey, stored_pkey, pkey_len);
truststore = efi_build_signature_store(pkey, pkey_len);
if (!truststore)
goto out;
diff --git a/lib/efi_loader/efi_capsule_key.S b/lib/efi_loader/efi_capsule_key.S
new file mode 100644
index 000000000000..58f00b8e4bcb
--- /dev/null
+++ b/lib/efi_loader/efi_capsule_key.S
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * .esl cert for capsule authentication
+ *
+ * Copyright (c) 2021, Ilias Apalodimas <ilias.apalodimas at linaro.org>
+ */
+
+#include <config.h>
+
+.section .rodata.capsule_key.init,"a"
+.balign 16
+.global __efi_capsule_sig_begin
+__efi_capsule_sig_begin:
+.incbin CONFIG_EFI_CAPSULE_KEY_PATH
+__efi_capsule_sig_end:
+.global __efi_capsule_sig_end
+.balign 16
--
2.31.1