[PATCHES] MSZIP support for cabinet files

[Jeremy Allison]

On Wed, Jun 28, 2017 at 12:18:00PM +0200, Aurélien Aptel wrote:
> Hi Jeremy,
> 
> This is in the push function, the checksum offset is obtained directly
> from the ndr writer offset here:
> 
> Jeremy Allison via samba-technical <samba-technical at lists.samba.org>
> writes:
> >> +
> >> +	for (i = 0; i < num_cfdata; i++, r++) {
> >> +		uint32_t compressed_offset, compressed_length = 0;
> >> +		uint32_t csum, csum_offset;
> >> +		uint32_t csumPartial;
> >> +
> >> +		/*
> >> +		 * checksum is a function of the size fields
> >> +		 * and the potentially compressed data bytes,
> >> +		 * which haven't been compressed yet so
> >> +		 * remember offset, write zeroes, fill out
> >> +		 * later
> >> +		 */
> >> +		csum_offset = ndr->offset;
> >> +		NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, 0));
> >> +
> 
> 
> >> +		csumPartial = ndr_cab_compute_checksum(&ndr->data[csum_offset + 8],
> >
> >                                                                  ^^^^^^^^^^^^^^^^
> >                                                                  Integer wrap checks ?
> > Didn't cnum_offset come from the client ?
> 
> 
> The expression will wrap around 4GB indeed but since many fields of CAB
> files are 32 bits I'm guessing it's also the file size hard limit of a
> CAB file.
> 
> Since it's the push function we should probably return an error early if
> the data to serialize is too big.
> 
> >> +			/* write in the folder header the offset of its first data block */
> >> +			for (i = 0; i < r->cfheader.cFolders; i++) {
> >> +				SIVAL(ndr->data, OFFSET_OF_FOLDER_COFFCABSTART(i), ndr->offset);
> >> +				NDR_CHECK(ndr_push_folder_cfdata(ndr, r->cfdata + processed_cfdata, r->cffolders[i].typeCompress, r->cffolders[i].cCFData));
> >> +				processed_cfdata += r->cffolders[i].cCFData;
> > 				^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > 				Here also ?
> 
> Same comment here I think.

OK, can you send an update with those things in. Just trying to
feel comfortable with this :-).