tools: kwbimage: Validate data checksum of v1 images

The data part of v1 images contains 32-bit checksum after the data.
Validate whether this checksum is correct.
Signed-off-by: NPali Rohár <pali@kernel.org>
Reviewed-by: NMarek Behún <marek.behun@nic.cz>
Reviewed-by: NStefan Roese <sr@denx.de>
Reviewed-by: NChris Packham <judge.packham@gmail.com>
Tested-by: NChris Packham <judge.packham@gmail.com>

tools/kwbimage.c

@@ -1672,6 +1672,8 @@ static int kwbimage_verify_header(unsigned char *ptr, int image_size,
 
 	if (image_version((void *)ptr) == 1) {
 		struct main_hdr_v1 *mhdr = (struct main_hdr_v1 *)ptr;
+		uint32_t offset;
+		uint32_t size;
 
 		if (mhdr->ext & 0x1) {
 			uint32_t ohdr_size;
@@ -1697,6 +1699,47 @@ static int kwbimage_verify_header(unsigned char *ptr, int image_size,
 							     ohdr_size);
 			}
 		}
+
+		offset = le32_to_cpu(mhdr->srcaddr);
+
+		/*
+		 * For SATA srcaddr is specified in number of sectors.
+		 * The main header is must be stored at sector number 1.
+		 * This expects that sector size is 512 bytes and recalculates
+		 * data offset to bytes relative to the main header.
+		 */
+		if (mhdr->blockid == IBR_HDR_SATA_ID) {
+			if (offset < 1)
+				return -FDT_ERR_BADSTRUCTURE;
+			offset -= 1;
+			offset *= 512;
+		}
+
+		/*
+		 * For SDIO srcaddr is specified in number of sectors.
+		 * This expects that sector size is 512 bytes and recalculates
+		 * data offset to bytes.
+		 */
+		if (mhdr->blockid == IBR_HDR_SDIO_ID)
+			offset *= 512;
+
+		/*
+		 * For PCIe srcaddr is always set to 0xFFFFFFFF.
+		 * This expects that data starts after all headers.
+		 */
+		if (mhdr->blockid == IBR_HDR_PEX_ID && offset == 0xFFFFFFFF)
+			offset = header_size;
+
+		if (offset > image_size || offset % 4 != 0)
+			return -FDT_ERR_BADSTRUCTURE;
+
+		size = le32_to_cpu(mhdr->blocksize);
+		if (offset + size > image_size || size % 4 != 0)
+			return -FDT_ERR_BADSTRUCTURE;
+
+		if (image_checksum32(ptr + offset, size - 4) !=
+		    *(uint32_t *)(ptr + offset + size - 4))
+			return -FDT_ERR_BADSTRUCTURE;
 	}
 
 	return 0;