DIGEST-MD5 fails to handle iso-8859-1 based names correctly.
Bug description
DIGEST-MD5 mandates that names which can be transformed into iso-8859-1 when using charset UTF-8 should be so tranformed prior to hash generation, in order to share the authentication database with HTTP.
Thus a user with a username, password, or realm which in entirely in iso-8859-1 characters cannot login to a conformant server (which includes Isode M-Link or Prosody).