sbsigntool fix (was Re: [PATCH] Fix PE/COFF checksum calculation)

[Steve McIntyre]

Sharing with others too. No idea if James is having mail problems or
something...

On Mon, Apr 29, 2019 at 03:55:10PM +0100, Steve McIntyre wrote:
>Hi James!
>
>Not had a response yet, I guess you're busy. Would a mailing list
>somewhere be better for this?
>
>On Fri, Apr 19, 2019 at 11:14:46PM +0100, Steve McIntyre wrote:
>>Hi James,
>>
>>Only count the cert_table header once when performing the calculation
>>and counting buffer sizes.
>>
>>Signed-off-by: Steve McIntyre <93sam at debian.org>
>>---
>> src/image.c | 6 +-----
>> 1 file changed, 1 insertion(+), 5 deletions(-)
>>
>>diff --git a/src/image.c b/src/image.c
>>index 745191f..3ada37b 100644
>>--- a/src/image.c
>>+++ b/src/image.c
>>@@ -162,7 +162,6 @@ static void image_pecoff_update_checksum(struct image *image)
>> {
>> 	bool is_signed = image->sigsize && image->sigbuf;
>> 	uint32_t checksum;
>>-	struct cert_table_header *cert_table = image->cert_table;
>> 
>> 	/* We carefully only include the signature data in the checksum (and
>> 	 * in the file length) if we're outputting the signature.  Otherwise,
>>@@ -180,16 +179,13 @@ static void image_pecoff_update_checksum(struct image *image)
>> 			(void *)(image->checksum + 1));
>> 
>> 	if (is_signed) {
>>-		checksum = csum_bytes(checksum,
>>-				cert_table, sizeof(*cert_table));
>>-
>> 		checksum = csum_bytes(checksum, image->sigbuf, image->sigsize);
>> 	}
>> 
>> 	checksum += image->data_size;
>> 
>> 	if (is_signed)
>>-		checksum += sizeof(*cert_table) + image->sigsize;
>>+		checksum += image->sigsize;
>> 
>> 	*(image->checksum) = cpu_to_le32(checksum);
>> }
>>-- 
>>2.20.1
>>
>>
>-- 
>Steve McIntyre, Cambridge, UK.                                steve at einval.com
>Is there anybody out there?
-- 
Steve McIntyre, Cambridge, UK.                                steve at einval.com
Into the distance, a ribbon of black
Stretched to the point of no turning back