[CentOS] Importing md5 encrypted passwords for el6

Carl T. Miller wrote:
> A couple of hours of reading man pages and Internet
> searches has left me clueless.  Is there a way to
> keep sha512 as the default and to enable usage of
> md5 in addition to sha512?

Yes, I'm embarrassed.  After asking for help, I
double-checked the shadow file and discovered that
the single quotes around the encrypted passwords
were read into /etc/shadow.  s/'//g fixed the problem.

As I suspected, md5 encrypted passwords can co-exist
with sha512 passwords.

c