[Pidgin] #4381: Add HMAC digest to libpurple

[Pidgin]

#4381: Add HMAC digest to libpurple
------------------------+---------------------------------------------------
  Reporter:  QuLogic    |       Owner:  grim        
      Type:  patch      |      Status:  new         
  Priority:  minor      |   Milestone:              
 Component:  libpurple  |     Version:  2.3.1       
Resolution:             |    Keywords:  HMAC, digest
   Pending:  0          |  
------------------------+---------------------------------------------------
Comment (by QuLogic):

 OK, updated this patch as well. It adds
 `purple_cipher_context_get_block_size` and
 `purple_cipher_context_set_key_with_len`.

 Since I've added to the !PurpleCipherOps structure in both #4380 and here,
 this one is probably dependant on you applying the previous patch first.
 I've noticed some fuzz when applying it, but it still seems to work
 alright.

-- 
Ticket URL: <http://developer.pidgin.im/ticket/4381#comment:3>
Pidgin <http://pidgin.im>
Pidgin