[cifs-protocol] is MS-DRSR 4.1.10.5.21 CompressOrDecompressWin2k3 the same as MS-WUSP 2.1.1.1 CompressOrDecompressWin2k3 ?

[Douglas Bagnall]

hi Dochelp.

The MS-DRSR and MS-WUSP definitions of CompressOrDecompressWin2k3 look very similar.
Are they really the same procedure?

If they are in fact the same, my next question is which document is most correct.
I haven't looked closely, but I see these differences:

MS-WUSP: This scheme is good for lengths of up to 279
MS-DRSR: This scheme is good for lengths of up to 278

MS-WUSP: a match length of up to 65,535 bytes + 3 bytes
MS-DRSR: a match length of up to 32,768 bytes + 3 bytes

Perhaps one has been updated and not the other?


In November 2022[1] I asked if MS-XCA 2.3 and 2.4 "Plain LZ77" was the same as the
MS-DRSR procedure. The answer was "MS-DRSR uses a different API than what MS-XCA uses",
which I took to mean that even if it was initially intended that they were the same,
they could easily be accidentally different. I guess my first question could be answered
in the same way -- are these using the same shared library function?

[1] https://lists.samba.org/archive/cifs-protocol/2022-November/003902.html

cheers,
Douglas