[PATCH u-boot-mvebu 09/31] tools: kwbimage: Validate data checksum of v1 images

[Marek Behún]

From: Pali Rohár <pali at kernel.org>

The data part of v1 images contains 32-bit checksum after the data.
Validate whether this checksum is correct.

Signed-off-by: Pali Rohár <pali at kernel.org>
Reviewed-by: Marek Behún <marek.behun at nic.cz>
---
 tools/kwbimage.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/tools/kwbimage.c b/tools/kwbimage.c
index 5f7cb8376a..de6eb3f075 100644
--- a/tools/kwbimage.c
+++ b/tools/kwbimage.c
@@ -1670,6 +1670,9 @@ 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;
+		unsigned char *endptr = ptr + sizeof(*mhdr);
+		uint32_t offset;
+		uint32_t size;
 
 		if (mhdr->ext & 0x1) {
 			uint32_t ohdr_size;
@@ -1693,7 +1696,50 @@ static int kwbimage_verify_header(unsigned char *ptr, int image_size,
 				ohdr = (struct opt_hdr_v1 *)((uint8_t *)ohdr +
 							     4 + ohdr_size + 4);
 			}
+
+			endptr = ((uint8_t *)ohdr + 4 + ohdr_size + 4);
+		}
+
+		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 = endptr - ptr;
+
+		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;
-- 
2.31.1