[Rd] missing binaries in R-devel windows snapshot 78175

[Jeroen Ooms]

On Fri, Apr 10, 2020 at 9:49 AM Martin Maechler
<maechler using stat.math.ethz.ch> wrote:
>
> >>>>> Jeroen Ooms
> >>>>>     on Fri, 10 Apr 2020 08:54:39 +0200 writes:
>
>     > On Fri, Apr 10, 2020 at 2:42 AM Bravington, Mark (Data61,
>     > Hobart) <Mark.Bravington using data61.csiro.au> wrote:
>     >>
>     >> > On Thu, Apr 9, 2020 at 12:44 PM Bravington, Mark
>     >> (Data61, Hobart) > <Mark.Bravington using data61.csiro.au>
>     >> wrote:
>     >> > >
>     >> > > The "r-devel snapshot build" 78175 on Windows--- a
>     >> dot-exe installer--- seems to be missing a couple of
>     >> files in its bin/i386 folder: Rterm.exe and
>     >> Rgui.exe. Both are present in its bin/x64 folder (and in
>     >> the i386 folder for current R).
>     >>
>     >> From: Jeroen Ooms <jeroen using berkeley.edu> Sent: Thursday, 9
>     >> April 2020 21:32 To: Bravington, Mark (Data61, Hobart)
>     >> Cc: R-Devel-2 Subject: Re: [Rd] missing binaries in
>     >> R-devel windows snapshot 78175
>     >>
>     >>
>     >> > I just tested this and as far as I can tell there are
>     >> no missing > files. Are you sure there isn't a local
>     >> problem with your system > permissions or antivirus that
>     >> is removing the files?
>     >>
>     >> You're quite right--- my apologies. I've been Cylanced
>     >> (without it having the politeness to actually tell me,
>     >> grrrr). I tried again with the 78172 build that you used,
>     >> and the two dot-exe files are there immediately after
>     >> installation--- but 10 minutes later they're gone. One
>     >> question below about the md5 stuff, though:
>     >>
>     >> > Try to verify the md5 of the installer; some enterprise
>     >> firewalls are > tampering with downloads:
>     >>
>     >> >
>     >> openssl::md5(url('https://cran.r-project.org/bin/windows/base/R-devel-win.exe'))
>     >> >
>     >> readLines('https://cran.r-project.org/bin/windows/base/md5sum.txt.R-devel')
>     >>
>     >> Thanks for the tip. I did that, and both give the same
>     >> output. But:
>     >>
>     >> - If I run 'md5sum' on my local copy of the 78182
>     >> installer (ie the file I've just downloaded) I again get
>     >> the same signature as per your two lines. (It's not the
>     >> firewall, it's Cylance.)
>     >>
>     >> - Yet if I run 'openssl::md5( <local copy of installer>)'
>     >> I get a different signature!
>
>     > I think you're calculating the md5 of the filename, not
>     > the file. You need to use:
>
>     >   openssl::md5(file("R-devel-win.exe"))
>
> or use base R's    tools::md5sum(<local-file-name>)
>
> md5sum() has existed forever, but needs you to do the
> download.file() step  which is indirectly happening in
> openssl::md5() also.

Not entirely the same way though! The openssl implementation of md5,
sha256, etc calculate the hash directly from the connection stream,
without ever storing the entire file on disk or in memory. It
efficiently hashes arbitrary large data from any readable R connection
(url, file, pipe, etc) using a fixed amount of memory. This is
important for researchers that calculate hashes for very large data
files, where copying the entire data to disk or memory is impossible.

However, in this case it's just a small file, so tools::md5sum() is
simpler indeed :)