I finally broke down and looked at the code for MySQL, particularly the portion for creating MD5 hashes.  Apparently, MySQl, takes the result that was being used in the SASL code and converts it to an ASCII representation of the result in hexadecimal notation.  It was an easy fix to checkpw.c to make it operate the same way.  I've included the function where I made the changes.  My notes are in bold.  Code that we're not using anymore is in italics.