[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

[augeas-devel] [Augeas] #53: The "editor" field in sudoers cannot be parsed properly



#53: The "editor" field in sudoers cannot be parsed properly
---------------------+------------------------------------------------------
 Reporter:  raphink  |       Owner:  lutter
     Type:  defect   |      Status:  new   
 Priority:  major    |   Milestone:  next  
Component:  Augeas   |     Version:  0.4.1 
 Keywords:           |  
---------------------+------------------------------------------------------
 See ticket #48 for previous discussion on this and proposed
 implementations.[[BR]]


 The "editor" parameter is a string which contains a colon-separated list
 of editors for visudo. The problem is that sto_to_com does not allow
 colons because they are used as separators in most lists in sudoers.[[BR]]


 Solutions:[[BR]]
 * We need either a separate parsing for "editor" which cuts down the list
 into params[[BR]]
 * or a separate sto_to_com entry which allows colons and is used for all
 string parameters

 [[BR]]

 I've tried to parse the contents of the "editor" parameter
  specifically... So, far, I'd call it a failure. This is the code I'm
 using
  :

  {{{
  (* "editor" is a special value that we parse as a colon-separated list
      Note: Spaces are allowed only _if_ the value is surrounded by quotes
             but I have no idea how to do that properly with augeas
      Values must begin with a "/"
  *)
  let parameter_string_editor_sto   =
                 store /\/[^": \t\n\\\\][^":\n\\\\]*[^":
  \t\n\\\\]|\/[^":\n\\\\]/
  let parameter_string_editor_value = [ label "name"
                                       . parameter_string_editor_sto ]
  let parameter_string_editor       = [ key "editor" . sep_eq
                                       . del /"?/ "\""
                                       . parameter_string_editor_value
                                       . ( sep_col
                                           . parameter_string_editor_value
  )*
                                       . del /"?/ "\"" ]
  }}}

  The problem is described in the comment. Here is an example of how it
  fails :

  Let's say I have an already existing "editor" entry in sudoers, which
 says
  :
  {{{
  editor = /usr/bin/nano
  }}}

  which is mapped as
  {{{
  /files/etc/sudoers/Defaults/editor
  /files/etc/sudoers/Defaults/editor/name = "/usr/bin/nano"
  }}}

  and I want to add a "/usr/bin/pico -A" entry (which is allowed), so I'd
 do
  :
  {{{
  set /files/etc/sudoers/Defaults/editor/name[2] "/usr/bin/pico -A"
  save
  }}}

  Augeas is happy with it, and I get :
  {{{
  editor=/usr/bin/nano : /usr/bin/pico -A
  }}}

  And there, visudo is not happy at all, because that is only possible if
  the values are surrounded by double quotes. So
  {{{
  editor="/usr/bin/nano : /usr/bin/pico -A"
  }}}

  is perfectly fine.[[BR]]

  This only happens if there is an already existing value for "editor" and
  it's not using double quotes, since I've set the lens to put double
 quotes
  by default if it creates the field.[[BR]]


  One could argue that using a sep_col which is not surrounded by spaces by
  default would fix the issue, but it only fixes it partly, and doesn't
  really correspond to the reality of what sudoers allows.[[BR]]

  I don't really have a clue, except to parse the whole field as a blob
 like
  I did so far. This last option is not perfect at all either, since "\\\n"
  separators are allowed within the "editor" values...

-- 
Ticket URL: <https://fedorahosted.org/augeas/ticket/53>
Augeas <http://augeas.net/>
a configuration API



[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]