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- // 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>
- #include <u-boot/sha256.h>
- /*
- * Offset of the image
- *
- * This value is used to skip the header before really launching the image
- */
- ulong image_load_offset;
- /*
- * This function gathers information about the signature check
- * that could be done before launching the image.
- *
- * return:
- * < 0 => 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 *sig_size;
- int key_len;
- int node, ret = 0;
- char *sig_info_path = NULL;
- if (!info) {
- log_err("ERROR: info is NULL for image pre-load sig check\n");
- ret = -EINVAL;
- goto out;
- }
- memset(info, 0, sizeof(*info));
- sig_info_path = env_get("pre_load_sig_info_path");
- if (!sig_info_path)
- sig_info_path = IMAGE_PRE_LOAD_PATH;
- node = fdt_path_offset(gd_fdt_blob(), sig_info_path);
- if (node < 0) {
- log_info("INFO: no info 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 = -EINVAL;
- goto out;
- }
- padding_name = fdt_getprop(gd_fdt_blob(), node,
- IMAGE_PRE_LOAD_PROP_PADDING_NAME, NULL);
- if (!padding_name) {
- log_info("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) {
- log_err("ERROR: no signature-size for image pre-load sig check\n");
- ret = -EINVAL;
- goto out;
- }
- key = fdt_getprop(gd_fdt_blob(), node,
- IMAGE_PRE_LOAD_PROP_PUBLIC_KEY, &key_len);
- if (!key) {
- log_err("ERROR: no key for image pre-load sig check\n");
- ret = -EINVAL;
- goto out;
- }
- 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;
- /* Compute signature information */
- info->sig_info.name = info->algo_name;
- info->sig_info.padding = image_get_padding_algo(info->padding_name);
- info->sig_info.checksum = image_get_checksum_algo(info->sig_info.name);
- info->sig_info.crypto = image_get_crypto_algo(info->sig_info.name);
- info->sig_info.key = info->key;
- info->sig_info.keylen = info->key_len;
- out:
- return ret;
- }
- static int image_pre_load_sig_get_magic(ulong addr, u32 *magic)
- {
- struct sig_header_s *sig_header;
- int ret = 0;
- sig_header = (struct sig_header_s *)map_sysmem(addr, SIG_HEADER_LEN);
- if (!sig_header) {
- log_err("ERROR: can't map first header\n");
- ret = -EFAULT;
- goto out;
- }
- *magic = fdt32_to_cpu(sig_header->magic);
- unmap_sysmem(sig_header);
- out:
- return ret;
- }
- static int image_pre_load_sig_get_header_size(ulong addr, u32 *header_size)
- {
- struct sig_header_s *sig_header;
- int ret = 0;
- sig_header = (struct sig_header_s *)map_sysmem(addr, SIG_HEADER_LEN);
- if (!sig_header) {
- log_err("ERROR: can't map first header\n");
- ret = -EFAULT;
- goto out;
- }
- *header_size = fdt32_to_cpu(sig_header->header_size);
- unmap_sysmem(sig_header);
- out:
- return ret;
- }
- /*
- * return:
- * < 0 => no magic and magic mandatory (or error when reading magic)
- * 0 => magic found
- * 1 => magic NOT found
- */
- static int image_pre_load_sig_check_magic(struct image_sig_info *info, ulong addr)
- {
- u32 magic;
- int ret = 1;
- ret = image_pre_load_sig_get_magic(addr, &magic);
- if (ret < 0)
- goto out;
- if (magic != IMAGE_PRE_LOAD_SIG_MAGIC) {
- if (info->mandatory) {
- log_err("ERROR: signature is mandatory\n");
- ret = -EINVAL;
- goto out;
- }
- ret = 1;
- goto out;
- }
- ret = 0; /* magic found */
- out:
- return ret;
- }
- static int image_pre_load_sig_check_header_sig(struct image_sig_info *info, ulong addr)
- {
- void *header;
- struct image_region reg;
- u32 sig_len;
- u8 *sig;
- int ret = 0;
- /* Only map header of the header and its signature */
- header = (void *)map_sysmem(addr, SIG_HEADER_LEN + info->sig_size);
- if (!header) {
- log_err("ERROR: can't map header\n");
- ret = -EFAULT;
- goto out;
- }
- reg.data = header;
- reg.size = SIG_HEADER_LEN;
- sig = (uint8_t *)header + SIG_HEADER_LEN;
- sig_len = info->sig_size;
- ret = info->sig_info.crypto->verify(&info->sig_info, ®, 1, sig, sig_len);
- if (ret) {
- log_err("ERROR: header signature check has failed (err=%d)\n", ret);
- ret = -EINVAL;
- goto out_unmap;
- }
- out_unmap:
- unmap_sysmem(header);
- out:
- return ret;
- }
- static int image_pre_load_sig_check_img_sig_sha256(struct image_sig_info *info, ulong addr)
- {
- struct sig_header_s *sig_header;
- u32 header_size, offset_img_sig;
- void *header;
- u8 sha256_img_sig[SHA256_SUM_LEN];
- int ret = 0;
- sig_header = (struct sig_header_s *)map_sysmem(addr, SIG_HEADER_LEN);
- if (!sig_header) {
- log_err("ERROR: can't map first header\n");
- ret = -EFAULT;
- goto out;
- }
- header_size = fdt32_to_cpu(sig_header->header_size);
- offset_img_sig = fdt32_to_cpu(sig_header->offset_img_sig);
- header = (void *)map_sysmem(addr, header_size);
- if (!header) {
- log_err("ERROR: can't map header\n");
- ret = -EFAULT;
- goto out_sig_header;
- }
- sha256_csum_wd(header + offset_img_sig, info->sig_size,
- sha256_img_sig, CHUNKSZ_SHA256);
- ret = memcmp(sig_header->sha256_img_sig, sha256_img_sig, SHA256_SUM_LEN);
- if (ret) {
- log_err("ERROR: sha256 of image signature is invalid\n");
- ret = -EFAULT;
- goto out_header;
- }
- out_header:
- unmap_sysmem(header);
- out_sig_header:
- unmap_sysmem(sig_header);
- out:
- return ret;
- }
- static int image_pre_load_sig_check_img_sig(struct image_sig_info *info, ulong addr)
- {
- struct sig_header_s *sig_header;
- u32 header_size, image_size, offset_img_sig;
- void *image;
- struct image_region reg;
- u32 sig_len;
- u8 *sig;
- int ret = 0;
- sig_header = (struct sig_header_s *)map_sysmem(addr, SIG_HEADER_LEN);
- if (!sig_header) {
- log_err("ERROR: can't map first header\n");
- ret = -EFAULT;
- goto out;
- }
- header_size = fdt32_to_cpu(sig_header->header_size);
- image_size = fdt32_to_cpu(sig_header->image_size);
- offset_img_sig = fdt32_to_cpu(sig_header->offset_img_sig);
- unmap_sysmem(sig_header);
- image = (void *)map_sysmem(addr, header_size + image_size);
- if (!image) {
- log_err("ERROR: can't map full image\n");
- ret = -EFAULT;
- goto out;
- }
- reg.data = image + header_size;
- reg.size = image_size;
- sig = (uint8_t *)image + offset_img_sig;
- sig_len = info->sig_size;
- ret = info->sig_info.crypto->verify(&info->sig_info, ®, 1, sig, sig_len);
- if (ret) {
- log_err("ERROR: signature check has failed (err=%d)\n", ret);
- ret = -EINVAL;
- goto out_unmap_image;
- }
- log_info("INFO: signature check has succeed\n");
- out_unmap_image:
- unmap_sysmem(image);
- out:
- return ret;
- }
- int image_pre_load_sig(ulong addr)
- {
- struct image_sig_info info;
- 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_check_magic(&info, addr);
- if (ret < 0)
- goto out;
- if (ret > 0) {
- ret = 0;
- goto out;
- }
- /* Check the signature of the signature header */
- ret = image_pre_load_sig_check_header_sig(&info, addr);
- if (ret < 0)
- goto out;
- /* Check sha256 of the image signature */
- ret = image_pre_load_sig_check_img_sig_sha256(&info, addr);
- if (ret < 0)
- goto out;
- /* Check the image signature */
- ret = image_pre_load_sig_check_img_sig(&info, addr);
- if (!ret) {
- u32 header_size;
- ret = image_pre_load_sig_get_header_size(addr, &header_size);
- if (ret) {
- log_err("%s: can't get header size\n", __func__);
- ret = -EINVAL;
- goto out;
- }
- image_load_offset += 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;
- }
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