bug#7155: [md5sum] does not accept

[Jim Meyering]

Pádraig Brady wrote:
> To summarize, the only caveat with my patch I think is that
> it will give a false error for BSD format checksums
> where the first entry has a file name starting with ' ' or '*'.
> That should be exceedingly rare though, and is a lot better
> than a false OK.

Oh.  I misunderstood.
We already accept one BSD variant:

  MD5 (f) = d41d8cd98f00b204e9800998ecf8427e

so I guess it's hard to reject another.

> Also in this case even without the patch, we're susceptible
> to the 'trojan' case above.
>
> The workaround is easy as you suggest:
>
>   sed 's/ /  /' files.md5 | md5sum -c
>
> However that is not easily discoverable.
> I'm 50:50, so I'll think a bit more.
> Hmm I might just document in info that
> the checksum utilities are compatible with
> the BSD ones when processed like:
>
>   md5 -r files... | sed 's/ /  /' > files.md5

Whichever you prefer.