rlm_pap code tidy

[Matthew Newton]

Hi,

More tidying - this time in rlm_pap. In chunks, it's at
https://github.com/mcnewton/freeradius-server/commits/rlm_pap_tidy
I've submitted a pull request; details for any comments below:

faa17a14 -
  removed the 'encryption_scheme' option entirely, together with
  the worthless switch() at the bottom.

a9d0b282 -
  the first update in getting rid of the spaghetti gotos. moves
  the crypt auth check into a separate function. patch looks
  messier than it is, as there's a lot of indentation changes.

d71b7e3b -
  the main update - move each auth test into a separate small
  function, to drastically reduce the size of pap_authenticate()
  and get rid of all the gotos. (I'm not against gotos, but when
  they jump in and out of ifs and switch()s, it's really hard to
  follow the code path!)

df48421a -
  previous introduced an few if()s inside the main attribute check
  loop, and returned within the loop. this tidies that up and
  moves that outside. also removes the reliance on
  RLM_MODULE_INVALID as a loop end test, which I wasn't keen on.

52b68318 -
  moves header-like stuff into rlm_pap.h

It now uses a function pointers to select the right auth function
depending on the config attribute found. I was slightly worried
that calling functions on this might slow things down a bit.
However, running 1000 auths in a tight loop (non-threaded server,
debug off) shows essentially no difference on my system - over
three runs, old code avg 23.516s, new code avg 23.464s.

Cheers,

Matthew


-- 
Matthew Newton, Ph.D. <mcn4 at le.ac.uk>

Systems Architect (UNIX and Networks), Network Services,
I.T. Services, University of Leicester, Leicester LE1 7RH, United Kingdom

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