[m-rev.] for review: Replace MD4 implementation with MD5.

[Peter Wang]

On Sat, 05 Jun 2021 09:33:16 +1000 "Zoltan Somogyi" <zoltan.somogyi at runbox.com> wrote:
> 
> 2021-06-03 15:31 GMT+10:00 "Peter Wang" <novalazy at gmail.com>:
> > We used MD4 digests in the implementation of the `--track-flags'feature. While there is no particular need to change, IIRC the only
> > reason I didn't use the more common MD5 algorithm is because I did not
> > know of a small portable implementation at the time.
> 
> I approve of the idea. Given that that most of the diff consists of
> external code, and the rest is trivial interface code, I don't think
> any further review is needed.
> 
> The obvious question is: does this get a warning/error from gcc 11?

I've managed to test it with gcc 11 now, and the answer is no.

BTW, the problem with the MD4 implementation was simply due to the
difference between the declaration and definition of this function:

static void mdfour_result(const struct mdfour *md, unsigned char out[12]);
static void mdfour_result(const struct mdfour *m, unsigned char *out)

Peter