This commit adds a stage pre-load that could check or modify an image.
For the moment, only a header with a signature is supported. This header has this format: - magic : 4 bytes - image size : 4 bytes - signature : n bytes - padding : up to header size
The stage use a node /image/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 - signature-size : size of the signature (in the header) - mandatory : set to yes if this sig is mandatory - public-key (madatory) : 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@softathome.com --- common/Kconfig.boot | 33 +++++ common/Makefile | 1 + common/image-pre-load.c | 291 ++++++++++++++++++++++++++++++++++++++++ include/image.h | 9 ++ 4 files changed, 334 insertions(+) create mode 100644 common/image-pre-load.c
diff --git a/common/Kconfig.boot b/common/Kconfig.boot index a8d4be23a9..916fdde71f 100644 --- a/common/Kconfig.boot +++ b/common/Kconfig.boot @@ -958,6 +958,39 @@ config AUTOBOOT_MENU_SHOW
endmenu
+menu "Image support" + +config IMAGE_PRE_LOAD + bool "Image pre-load support" + help + Enable image pre-load support + +config SPL_IMAGE_PRE_LOAD + bool "Image pre-load support within SPL" + depends on SPL && IMAGE_PRE_LOAD + help + Enable image pre-load support in SPL + +config IMAGE_PRE_LOAD_SIG + bool "Image pre-load signature support" + depends on IMAGE_PRE_LOAD + select FIT_SIGNATURE + select RSA + select RSA_VERIFY_WITH_PKEY + help + Enable image pre-load signature support + +config SPL_IMAGE_PRE_LOAD_SIG + bool "Image pre-load signature support witin SPL" + depends on SPL_IMAGE_PRE_LOAD && IMAGE_PRE_LOAD_SIG + select SPL_FIT_SIGNATURE + select SPL_RSA + select SPL_RSA_VERIFY_WITH_PKEY + help + Enable image pre-load signature support in SPL + +endmenu + config USE_BOOTARGS bool "Enable boot arguments" help diff --git a/common/Makefile b/common/Makefile index e7839027b6..9b322e3ae4 100644 --- a/common/Makefile +++ b/common/Makefile @@ -102,6 +102,7 @@ endif endif
obj-y += image.o image-board.o +obj-$(CONFIG_$(SPL_TPL_)IMAGE_PRE_LOAD) += image-pre-load.o obj-$(CONFIG_$(SPL_TPL_)HASH) += hash.o obj-$(CONFIG_ANDROID_AB) += android_ab.o obj-$(CONFIG_ANDROID_BOOT_IMAGE) += image-android.o image-android-dt.o diff --git a/common/image-pre-load.c b/common/image-pre-load.c new file mode 100644 index 0000000000..6ed21c3f51 --- /dev/null +++ b/common/image-pre-load.c @@ -0,0 +1,291 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2021 Philippe Reynes philippe.reynes@softathome.com + */ + +#include <common.h> +#include <asm/global_data.h> +DECLARE_GLOBAL_DATA_PTR; +#include <image.h> +#include <mapmem.h> + +#define IMAGE_PRE_LOAD_SIG_MAGIC 0x55425348 +#define IMAGE_PRE_LOAD_SIG_OFFSET_MAGIC 0 +#define IMAGE_PRE_LOAD_SIG_OFFSET_IMG_LEN 4 +#define IMAGE_PRE_LOAD_SIG_OFFSET_SIG 8 + +#define IMAGE_PRE_LOAD_PATH "/image/pre-load/sig" +#define IMAGE_PRE_LOAD_PROP_HEADER_SIZE "header-size" +#define IMAGE_PRE_LOAD_PROP_ALGO_NAME "algo-name" +#define IMAGE_PRE_LOAD_PROP_PADDING_NAME "padding-name" +#define IMAGE_PRE_LOAD_PROP_SIG_SIZE "signature-size" +#define IMAGE_PRE_LOAD_PROP_PUBLIC_KEY "public-key" +#define IMAGE_PRE_LOAD_PROP_MANDATORY "mandatory" + +#ifndef CONFIG_SYS_BOOTM_LEN +/* use 8MByte as default max gunzip size */ +#define CONFIG_SYS_BOOTM_LEN 0x800000 +#endif + +struct image_sig_header { + u32 magic; + u32 size; + u8 *sig; +}; + +struct image_sig_info { + ulong header_size; + char *algo_name; + char *padding_name; + u8 *key; + int key_len; + u32 sig_size; + int mandatory; +}; + +ulong image_load_offset; + +/* + * This function gathers information about the signature check + * that could be done before launching the image. + * + * return: + * -1 => an error has occurred + * 0 => OK + * 1 => no setup + */ +static int image_pre_load_sig_setup(struct image_sig_info *info) +{ + const void *algo_name, *padding_name, *key, *mandatory; + const u32 *header_size, *sig_size; + int key_len; + int node, ret = 0; + + if (!info) { + printf("ERROR: info is NULL for image pre-load sig check\n"); + ret = -1; + goto out; + } + + memset(info, 0, sizeof(*info)); + + node = fdt_path_offset(gd_fdt_blob(), IMAGE_PRE_LOAD_PATH); + if (node < 0) { + printf("INFO: no info for image pre-load sig check\n"); + ret = 1; + goto out; + } + + header_size = fdt_getprop(gd_fdt_blob(), node, + IMAGE_PRE_LOAD_PROP_HEADER_SIZE, NULL); + if (!header_size) { + printf("ERROR: no header-size for image pre-load sig check\n"); + ret = -1; + goto out; + } + + algo_name = fdt_getprop(gd_fdt_blob(), node, + IMAGE_PRE_LOAD_PROP_ALGO_NAME, NULL); + if (!algo_name) { + printf("ERROR: no algo_name for image pre-load sig check\n"); + ret = -1; + goto out; + } + + padding_name = fdt_getprop(gd_fdt_blob(), node, + IMAGE_PRE_LOAD_PROP_PADDING_NAME, NULL); + if (!padding_name) { + printf("INFO: no padding_name provided, so using pkcs-1.5\n"); + padding_name = "pkcs-1.5"; + } + + sig_size = fdt_getprop(gd_fdt_blob(), node, + IMAGE_PRE_LOAD_PROP_SIG_SIZE, NULL); + if (!sig_size) { + printf("ERROR: no signature-size for image pre-load sig check\n"); + ret = -1; + goto out; + } + + key = fdt_getprop(gd_fdt_blob(), node, + IMAGE_PRE_LOAD_PROP_PUBLIC_KEY, &key_len); + if (!key) { + printf("ERROR: no key for image 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; + info->sig_size = fdt32_to_cpu(*sig_size); + + mandatory = fdt_getprop(gd_fdt_blob(), node, + IMAGE_PRE_LOAD_PROP_MANDATORY, NULL); + if (mandatory && !strcmp((char *)mandatory, "yes")) + info->mandatory = 1; + + out: + return ret; +} + +static int image_pre_load_sig_get_header_u32(struct image_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 image pre-load sig\n"); + ret = -1; + goto out; + } + + tmp = header + offset; + *value = be32_to_cpu(*tmp); + + unmap_sysmem(header); + + out: + return ret; +} + +static int image_pre_load_sig_get_magic(struct image_sig_info *info, + ulong addr, u32 *magic) +{ + int ret; + + ret = image_pre_load_sig_get_header_u32(info, addr, + IMAGE_PRE_LOAD_SIG_OFFSET_MAGIC, magic); + + return ret; +} + +static int image_pre_load_sig_get_img_len(struct image_sig_info *info, + ulong addr, u32 *len) +{ + int ret; + + ret = image_pre_load_sig_get_header_u32(info, addr, + IMAGE_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; + } + + if (*len == 0) { + printf("ERROR: size of image (%u) is zero\n", *len); + ret = -1; + goto out; + } + + out: + return ret; +} + +static int image_pre_load_sig_check(struct image_sig_info *info, ulong addr, int img_len) +{ + void *image; + struct image_sign_info sig_info; + struct image_region reg; + u32 sig_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; + + sig = (uint8_t *)image + IMAGE_PRE_LOAD_SIG_OFFSET_SIG; + sig_len = info->sig_size; + + ret = sig_info.crypto->verify(&sig_info, ®, 1, sig, sig_len); + if (ret) { + printf("ERROR: signature check has failed (err=%d)\n", ret); + ret = -1; + goto out_unmap; + } + + printf("INFO: signature check has succeed\n"); + +out_unmap: + unmap_sysmem(image); + + out: + return ret; +} + +int image_pre_load_sig(ulong addr) +{ + struct image_sig_info info; + u32 magic, img_len; + int ret; + + ret = image_pre_load_sig_setup(&info); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + goto out; + } + + ret = image_pre_load_sig_get_magic(&info, addr, &magic); + if (ret < 0) + goto out; + + if (magic != IMAGE_PRE_LOAD_SIG_MAGIC) { + if (info.mandatory) { + printf("ERROR: signature is mandatory\n"); + ret = -1; + } + goto out; + } + + ret = image_pre_load_sig_get_img_len(&info, addr, &img_len); + if (ret < 0) + goto out; + + ret = image_pre_load_sig_check(&info, addr, img_len); + + if (!ret) + image_load_offset += info.header_size; + + out: + return ret; +} + +int image_pre_load(ulong addr) +{ + int ret = 0; + + image_load_offset = 0; + + if (CONFIG_IS_ENABLED(IMAGE_PRE_LOAD_SIG)) + ret = image_pre_load_sig(addr); + + return ret; +} diff --git a/include/image.h b/include/image.h index fd662e74b4..5f83e4c747 100644 --- a/include/image.h +++ b/include/image.h @@ -48,6 +48,7 @@ struct fdt_region; extern ulong image_load_addr; /* Default Load Address */ extern ulong image_save_addr; /* Default Save Address */ extern ulong image_save_size; /* Default Save Size */ +extern ulong image_load_offset; /* Default Load Address Offset */
/* An invalid size, meaning that the image size is not known */ #define IMAGE_SIZE_INVAL (-1UL) @@ -1289,6 +1290,14 @@ struct crypto_algo *image_get_crypto_algo(const char *full_name); */ struct padding_algo *image_get_padding_algo(const char *name);
+/** + * image_pre_load() - Manage pre load header + * + * @param addr Address of the image + * @return: 0 on success, -ve on error + */ +int image_pre_load(ulong addr); + /** * fit_image_verify_required_sigs() - Verify signatures marked as 'required' *