boot/image-pre-load.c - platform/external/u-boot - Gitiles

 // 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, &reg, 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, &reg, 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;
 }
	// 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, &reg, 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, &reg, 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;
	}