| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Copyright (C) 2021 Philippe Reynes <philippe.reynes@softathome.com> |
| */ |
| |
| #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; |
| } |