Class: Cbac::CbacPristine::AbstractPristineFile

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
lib/cbac/cbac_pristine/pristine_file.rb

Direct Known Subclasses

GenericPristineFile, PristineFile

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ AbstractPristineFile

Returns a new instance of AbstractPristineFile.



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# File 'lib/cbac/cbac_pristine/pristine_file.rb', line 11

def initialize(*args)
  super(*args)
  @generic_roles = []
  @context_roles = []
  @permissions = []
end

Instance Attribute Details

#generic_roles ⇒ Object

Returns the value of attribute generic_roles.



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# File 'lib/cbac/cbac_pristine/pristine_file.rb', line 8

def generic_roles
  @generic_roles
end

#permissions ⇒ Object

Returns the value of attribute permissions.



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# File 'lib/cbac/cbac_pristine/pristine_file.rb', line 8

def permissions
  @permissions
end

Instance Method Details

#is_pristine_permission_line?(line, line_number) ⇒ Boolean

Returns:

  • (Boolean)

Raises:

  • (SyntaxError) 


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# File 'lib/cbac/cbac_pristine/pristine_file.rb', line 70

def is_pristine_permission_line?(line, line_number)
  if line.match(/^\s*(\d+)\s*:\s*([\+-x]|=>)\s*:(\s*[A-Za-z]+\(\s*[A-Za-z_]*\s*\))+\s*\Z/) #looks like pristine line.....
    return true
  end
  if line.match(/^\s*(#.*|\s*)$/) # line is whitespace or comment line
    return false
  end
  raise SyntaxError, "Error: garbage found in input file on line #{(line_number + 1).to_s}" #line is rubbish
end

#parse(use_db = true) ⇒ Object 



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# File 'lib/cbac/cbac_pristine/pristine_file.rb', line 18

def parse(use_db = true)
  @generic_roles = []
  @context_roles = []
  @permissions = []

  f = File.open(file_name, "r")
  last_row_number = -1
  f.each_with_index do |l, line_number|
    pristine_permission = PristinePermission.new
    pristine_permission.pristine_file = self
    permission_line = l.chomp
    # if this is not a line we can convert into a permission, go to next line (or fail.....)
    next unless is_pristine_permission_line?(permission_line, line_number)

    # check if the row numbers are constructed properly.
    # this is needed for migration purposes, each permission should have an unique and persistent row number
    header_match = permission_line.match(/^(\d+):([\+-x]|=>):\s*/)
    pristine_permission.line_number = header_match.captures[0].to_i
    if pristine_permission.line_number != last_row_number.succ
      raise SyntaxError, "Error: row numbers in pristine file do not increase monotonously"
    else
      last_row_number = pristine_permission.line_number
    end
    pristine_permission.operation = header_match.captures[1]
    # parse the role and privilege set name
    pristine_permission.privilege_set_name = parse_privilege_set_name(permission_line, line_number)
    pristine_permission.pristine_role = parse_role(permission_line, line_number, use_db)
    # it's pristine, so changes should be treated as such
    # if a permission was created and later revoked, we should remove the pristine line which was created before
    case pristine_permission.operation
      when '+'
        @permissions.push(pristine_permission)
      when '-'
        permission_to_delete = nil
        #check if this is actually a permission that can be revoked.
        @permissions.each do |known_permission|
          if known_permission.privilege_set_name == pristine_permission.privilege_set_name and known_permission.pristine_role.name == pristine_permission.pristine_role.name
            permission_to_delete = known_permission
            break
          end
        end
        if permission_to_delete.nil?
          raise SyntaxError, "Error: trying to remove a privilege set with \"#{permission_line}\" on line #{(line_number + 1).to_s}, but this privilege set wasn't created!"
        else
          @permissions.push(pristine_permission)
        end
      when 'x', '=>'
        raise NotImplementedError, "Using an x or => in a pristine file is not implemented yet"
    end
  end
end

#parse_privilege_set_name(line, line_number) ⇒ Object

Raises:

  • (SyntaxError) 


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# File 'lib/cbac/cbac_pristine/pristine_file.rb', line 80

def parse_privilege_set_name(line, line_number)
  if match_data= line.match(/^.*PrivilegeSet\(\s*([A-Za-z0-9_]+)\s*\)\s*/)
    return match_data.captures[0]
  end
  raise SyntaxError, "Error: PrivilegeSet expected, but found: \"#{line}\" on line #{(line_number + 1).to_s}"
end

#parse_role(line, line_number, use_db = true) ⇒ Object 



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# File 'lib/cbac/cbac_pristine/pristine_file.rb', line 87

def parse_role(line, line_number, use_db = true)
  raise NotImplementedError("Error: the AbstractPristineFile cannot parse roles, use a PristineFile or GenericPristineFile instead")
end

#permission_set ⇒ Object 



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# File 'lib/cbac/cbac_pristine/pristine_file.rb', line 91

def permission_set
  permission_set = Array.new(@permissions)
  @permissions.each do |pristine_permission|
     case pristine_permission.operation
      when '+'
        permission_set.push(pristine_permission)
      when '-'
        permission_to_delete = nil
        #check if this is actually a permission that can be revoked.
        permission_set.each do |known_permission|
          if known_permission.privilege_set_name == pristine_permission.privilege_set_name and known_permission.pristine_role.name == pristine_permission.pristine_role.name and known_permission.operation == '+'
            permission_to_delete = known_permission
            break
          end
        end
        if permission_to_delete.nil?
          raise ArgumentError, "Error: trying to remove permission #{pristine_permission.privilege_set_name}\" for #{pristine_permission.pristine_role.name}, but this permission wasn't created!"
        else
          permission_set.delete(permission_to_delete)
          permission_set.delete(pristine_permission)
        end
      when 'x', '=>'
        raise NotImplementedError, "Using an x or => in a pristine file is not implemented yet"
    end
  end
  permission_set
end