since they don't have an easily recognizable signature, was if they
were the default. This commit rewrites crypt_set_format(3) etc to
address this:
- Use a pointer instead of an index to identify the default format.
This pointer is initialized at compile time to point to the first
first element in the list of supported formats, eliminating the
need for crypt_setdefault(). Using a pointer also simplifies
iterating through the list.
- Associate DES with the magic string "_", which takes care of the
Extended DES format.
- Finally, as a special case, if the salt does not match any known
magic string but matches ^[./0-9A-Za-z]{13}$, it is assumed to be a
DES password and is passed on to crypt_des().
MFC after: 1 week
5280a31478