This commit adds a stage pre-load that could
check or modify the image provided to the bootm
command.
For the moment, only a header with a signature is
supported. This header has this format:
- magic : 4 bytes
- image size : 4 bytes
- sig size : 4 bytes
- signature : n bytes
- padding : up to header size
The stage use a node /bootm/pre-load/sig to
get some information:
- header-size (mandatory) : size of the header
- algo-name (mandatory) : name of the algo used to sign
- padding-name : name of padding used to sign
- mandatory : set to yes if this sig is mandatory
- public-key : value of the public key
Before running the image, the stage pre-load check
the signature provided in the header.
This is an initial support, later we could add the
support of:
- ciphering
- uncompressing
- ...
Signed-off-by: Philippe Reynes <philippe.reynes(a)softathome.com>
---
cmd/Kconfig | 9 ++
cmd/bootm.c | 2 +-
common/bootm.c | 258 ++++++++++++++++++++++++++++++++++++++++++++++++
include/image.h | 1 +
4 files changed, 269 insertions(+), 1 deletion(-)
diff --git a/cmd/Kconfig b/cmd/Kconfig
index eff238cb38..086d2b7b74 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -194,6 +194,15 @@ config CMD_BOOTM
help
Boot an application image from the memory.
+config CMD_BOOTM_PRE_LOAD
+ bool "enable pre-load on bootm"
+ depends on CMD_BOOTM
+ default n
+ help
+ Enable support of stage pre-load for the bootm command.
+ This stage allow to check of modifty the image provided
+ to the bootm command.
+
config BOOTM_EFI
bool "Support booting UEFI FIT images"
depends on CMD_BOOTEFI && CMD_BOOTM && FIT
diff --git a/cmd/bootm.c b/cmd/bootm.c
index 81c6b93978..7a6299d8d8 100644
--- a/cmd/bootm.c
+++ b/cmd/bootm.c
@@ -126,7 +126,7 @@ int do_bootm(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
}
return do_bootm_states(cmdtp, flag, argc, argv, BOOTM_STATE_START |
- BOOTM_STATE_FINDOS | BOOTM_STATE_FINDOTHER |
+ BOOTM_STATE_FINDOS | BOOTM_STATE_PRE_LOAD | BOOTM_STATE_FINDOTHER |
BOOTM_STATE_LOADOS |
#ifdef CONFIG_SYS_BOOT_RAMDISK_HIGH
BOOTM_STATE_RAMDISK |
diff --git a/common/bootm.c b/common/bootm.c
index defaed8426..37b1340023 100644
--- a/common/bootm.c
+++ b/common/bootm.c
@@ -42,6 +42,12 @@
#define IH_INITRD_ARCH IH_ARCH_DEFAULT
+#define BOOTM_PRE_LOAD_SIG_MAGIC 0x55425348
+#define BOOTM_PRE_LOAD_SIG_OFFSET_MAGIC 0
+#define BOOTM_PRE_LOAD_SIG_OFFSET_IMG_LEN 4
+#define BOOTM_PRE_LOAD_SIG_OFFSET_SIG_LEN 8
+#define BOOTM_PRE_LOAD_SIG_OFFSET_SIG 12
+
#ifndef USE_HOSTCC
DECLARE_GLOBAL_DATA_PTR;
@@ -87,6 +93,255 @@ static int bootm_start(struct cmd_tbl *cmdtp, int flag, int argc,
return 0;
}
+static ulong bootm_data_addr(int argc, char *const argv[])
+{
+ ulong addr;
+
+ if (argc > 0)
+ addr = simple_strtoul(argv[0], NULL, 16);
+ else
+ addr = image_load_addr;
+
+ return addr;
+}
+
+struct bootm_sig_header {
+ u32 magic;
+ u32 size;
+ u8 *sig;
+};
+
+struct bootm_sig_info {
+ ulong header_size;
+ char *algo_name;
+ char *padding_name;
+ u8 *key;
+ int key_len;
+ int mandatory;
+};
+
+/*
+ * This function gather information about the signature check
+ * that could be done in the pre-load stage of bootm.
+ *
+ * return:
+ * -1 => an error has occurred
+ * 0 => OK
+ * 1 => no setup
+ */
+static int bootm_pre_load_sig_setup(struct bootm_sig_info *info)
+{
+ const void *algo_name, *padding_name, *key, *mandatory;
+ const u32 *header_size;
+ int key_len;
+ int node, ret = 0;
+
+ if (!info) {
+ printf("ERROR: info is NULL for bootm pre-load sig check\n");
+ ret = -1;
+ goto out;
+ }
+
+ memset(info, 0, sizeof(*info));
+
+ node = fdt_path_offset(gd->fdt_blob, "/bootm/pre-load/sig");
+ if (node < 0) {
+ printf("INFO: no info for bootm pre-load sig check\n");
+ ret = 1;
+ goto out;
+ }
+
+ header_size = fdt_getprop(gd->fdt_blob, node, "header-size", NULL);
+ if (!header_size) {
+ printf("ERROR: no header-size for bootm pre-load sig check\n");
+ ret = -1;
+ goto out;
+ }
+
+ algo_name = fdt_getprop(gd->fdt_blob, node, "algo-name", NULL);
+ if (!algo_name) {
+ printf("ERROR: no algo_name for bootm pre-load sig check\n");
+ ret = -1;
+ goto out;
+ }
+
+ padding_name = fdt_getprop(gd->fdt_blob, node, "padding-name", NULL);
+ if (!padding_name) {
+ printf("INFO: no padding_name provided, so using pkcs-1.5\n");
+ padding_name = "pkcs-1.5";
+ }
+
+ key = fdt_getprop(gd->fdt_blob, node, "public-key", &key_len);
+ if (!key) {
+ printf("ERROR: no key for bootm pre-load sig check\n");
+ ret = -1;
+ goto out;
+ }
+
+ info->header_size = fdt32_to_cpu(*header_size);
+ info->algo_name = (char *)algo_name;
+ info->padding_name = (char *)padding_name;
+ info->key = (uint8_t *)key;
+ info->key_len = key_len;
+
+ mandatory = fdt_getprop(gd->fdt_blob, node, "mandatory", NULL);
+ if (mandatory && !strcmp((char *)mandatory, "yes"))
+ info->mandatory = 1;
+
+ out:
+ return ret;
+}
+
+static int bootm_pre_load_sig_get_header_u32(struct bootm_sig_info *info,
+ ulong addr, u32 offset,
+ u32 *value)
+{
+ void *header;
+ u32 *tmp;
+ int ret = 0;
+
+ header = map_sysmem(addr, info->header_size);
+ if (!header) {
+ printf("ERROR: can't map header bootm pre-load sig\n");
+ ret = -1;
+ goto out;
+ }
+
+ tmp = header + offset;
+ *value = be32_to_cpu(*tmp);
+
+ unmap_sysmem(header);
+
+ out:
+ return ret;
+}
+
+static int bootm_pre_load_sig_get_magic(struct bootm_sig_info *info,
+ ulong addr, u32 *magic)
+{
+ int ret;
+
+ ret = bootm_pre_load_sig_get_header_u32(info, addr,
+ BOOTM_PRE_LOAD_SIG_OFFSET_MAGIC, magic);
+
+ return ret;
+}
+
+static int bootm_pre_load_sig_get_img_len(struct bootm_sig_info *info,
+ ulong addr, u32 *len)
+{
+ int ret;
+
+ ret = bootm_pre_load_sig_get_header_u32(info, addr,
+ BOOTM_PRE_LOAD_SIG_OFFSET_IMG_LEN, len);
+ if (ret < 0)
+ goto out;
+
+ if (*len > CONFIG_SYS_BOOTM_LEN) {
+ printf("ERROR: size of image (%u) bigger than CONFIG_SYS_BOOTM_LEN (%u)\n",
+ *len, CONFIG_SYS_BOOTM_LEN);
+ ret = -1;
+ goto out;
+ }
+
+ out:
+ return ret;
+}
+
+static int bootm_pre_load_sig_check(struct bootm_sig_info *info, ulong addr, int img_len)
+{
+ void *image;
+ struct image_sign_info sig_info;
+ struct image_region reg;
+ u32 sig_len, *psig_len;
+ u8 *sig;
+ int ret = 0;
+
+ image = (void *)map_sysmem(addr, info->header_size + img_len);
+ if (!image) {
+ printf("ERROR: can't map full image\n");
+ ret = -1;
+ goto out;
+ }
+
+ memset(&sig_info, '\0', sizeof(sig_info));
+ sig_info.name = info->algo_name;
+ sig_info.padding = image_get_padding_algo(info->padding_name);
+ sig_info.checksum = image_get_checksum_algo(sig_info.name);
+ sig_info.crypto = image_get_crypto_algo(sig_info.name);
+ sig_info.key = info->key;
+ sig_info.keylen = info->key_len;
+
+ reg.data = image + info->header_size;
+ reg.size = img_len;
+
+ psig_len = (uint32_t *)((uint8_t *)image + BOOTM_PRE_LOAD_SIG_OFFSET_SIG_LEN);
+ sig_len = be32_to_cpu(*psig_len);
+ sig = (uint8_t *)image + BOOTM_PRE_LOAD_SIG_OFFSET_SIG;
+
+ ret = sig_info.crypto->verify(&sig_info, ®, 1, sig, sig_len);
+ if (ret < 0)
+ printf("ERROR: signature check has failed (err=%d)\n", ret);
+
+ memmove(image, image + info->header_size, img_len);
+
+ unmap_sysmem(image);
+
+ out:
+ return ret;
+}
+
+static int bootm_pre_load_sig(ulong addr)
+{
+ struct bootm_sig_info info;
+ u32 magic, img_len;
+ int ret;
+
+ ret = bootm_pre_load_sig_setup(&info);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+
+ ret = bootm_pre_load_sig_get_magic(&info, addr, &magic);
+ if (ret < 0)
+ goto out;
+
+ if (magic != BOOTM_PRE_LOAD_SIG_MAGIC) {
+ if (info.mandatory) {
+ printf("ERROR: signature is mandatory\n");
+ ret = -1;
+ }
+ goto out;
+ }
+
+ ret = bootm_pre_load_sig_get_img_len(&info, addr, &img_len);
+ if (ret < 0)
+ goto out;
+
+ ret = bootm_pre_load_sig_check(&info, addr, img_len);
+
+ out:
+ return ret;
+}
+
+static int bootm_pre_load(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ ulong data_addr = bootm_data_addr(argc, argv);
+ int ret = 0;
+
+ if (CONFIG_IS_ENABLED(CMD_BOOTM_PRE_LOAD))
+ ret = bootm_pre_load_sig(data_addr);
+
+ if (ret)
+ ret = CMD_RET_FAILURE;
+
+ return ret;
+}
+
static int bootm_find_os(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
@@ -676,6 +931,9 @@ int do_bootm_states(struct cmd_tbl *cmdtp, int flag, int argc,
if (states & BOOTM_STATE_START)
ret = bootm_start(cmdtp, flag, argc, argv);
+ if (!ret && (states & BOOTM_STATE_PRE_LOAD))
+ ret = bootm_pre_load(cmdtp, flag, argc, argv);
+
if (!ret && (states & BOOTM_STATE_FINDOS))
ret = bootm_find_os(cmdtp, flag, argc, argv);
diff --git a/include/image.h b/include/image.h
index b4b284d52b..bd72b49913 100644
--- a/include/image.h
+++ b/include/image.h
@@ -432,6 +432,7 @@ typedef struct bootm_headers {
#define BOOTM_STATE_OS_PREP (0x00000100)
#define BOOTM_STATE_OS_FAKE_GO (0x00000200) /* 'Almost' run the OS */
#define BOOTM_STATE_OS_GO (0x00000400)
+#define BOOTM_STATE_PRE_LOAD (0x00000800)
int state;
#ifdef CONFIG_LMB
--
2.17.1
