[PATCH u-boot-marvell 04/13] tools: kwboot: Validate 4-byte image data checksum

[Stefan Roese]

On 25.10.21 15:12, Marek Behún wrote:
> From: Pali Rohár <pali at kernel.org>
> 
> Data part of the image contains 4-byte checksum. Validate it when
> processing the image.
> 
> Signed-off-by: Pali Rohár <pali at kernel.org>
> [ refactored ]
> Signed-off-by: Marek Behún <marek.behun at nic.cz>

Reviewed-by: Stefan Roese <sr at denx.de>

Thanks,
Stefan

> ---
>   tools/kwboot.c | 34 ++++++++++++++++++++++++++++++++++
>   1 file changed, 34 insertions(+)
> 
> diff --git a/tools/kwboot.c b/tools/kwboot.c
> index 4e29317f10..bc44301535 100644
> --- a/tools/kwboot.c
> +++ b/tools/kwboot.c
> @@ -1251,6 +1251,37 @@ kwboot_hdr_csum8(const void *hdr)
>   	return csum;
>   }
>   
> +static uint32_t *
> +kwboot_img_csum32_ptr(void *img)
> +{
> +	struct main_hdr_v1 *hdr = img;
> +	uint32_t datasz;
> +
> +	datasz = le32_to_cpu(hdr->blocksize) - sizeof(uint32_t);
> +
> +	return img + le32_to_cpu(hdr->srcaddr) + datasz;
> +}
> +
> +static uint32_t
> +kwboot_img_csum32(const void *img)
> +{
> +	const struct main_hdr_v1 *hdr = img;
> +	uint32_t datasz, csum = 0;
> +	const uint32_t *data;
> +
> +	datasz = le32_to_cpu(hdr->blocksize) - sizeof(csum);
> +	if (datasz % sizeof(uint32_t))
> +		return 0;
> +
> +	data = img + le32_to_cpu(hdr->srcaddr);
> +	while (datasz > 0) {
> +		csum += le32_to_cpu(*data++);
> +		datasz -= 4;
> +	}
> +
> +	return cpu_to_le32(csum);
> +}
> +
>   static int
>   kwboot_img_is_secure(void *img)
>   {
> @@ -1462,6 +1493,9 @@ kwboot_img_patch(void *img, size_t *size, int baudrate)
>   	    *size < le32_to_cpu(hdr->srcaddr) + le32_to_cpu(hdr->blocksize))
>   		goto err;
>   
> +	if (kwboot_img_csum32(img) != *kwboot_img_csum32_ptr(img))
> +		goto err;
> +
>   	is_secure = kwboot_img_is_secure(img);
>   
>   	if (hdr->blockid != IBR_HDR_UART_ID) {
> 


Viele Grüße,
Stefan

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