Class: Zxcvbn::Matchers::Spatial

Inherits:
Object
  • Object
show all
Defined in:
lib/zxcvbn/matchers/spatial.rb

Instance Method Summary collapse

Constructor Details

#initialize(graphs) ⇒ Spatial

Returns a new instance of Spatial.



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# File 'lib/zxcvbn/matchers/spatial.rb', line 4

def initialize(graphs)
  @graphs = graphs
end

Instance Method Details

#matches(password) ⇒ Object 



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# File 'lib/zxcvbn/matchers/spatial.rb', line 8

def matches(password)
  results = []
  @graphs.each do |graph_name, graph|
    results += matches_for_graph(graph, graph_name, password)
  end
  results
end

#matches_for_graph(graph, graph_name, password) ⇒ Object 



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# File 'lib/zxcvbn/matchers/spatial.rb', line 16

def matches_for_graph(graph, graph_name, password)
  result = []
  i = 0
  while i < password.length - 1
    j = i + 1
    last_direction = nil
    turns = 0
    shifted_count = 0
    loop do
      prev_char = password[j-1]
      found = false
      found_direction = -1
      cur_direction = -1
      adjacents = graph[prev_char] || []
      # consider growing pattern by one character if j hasn't gone over the edge.
      if j < password.length
        cur_char = password[j]
        adjacents.each do |adj|
          cur_direction += 1
          if adj && adj.index(cur_char)
            found = true
            found_direction = cur_direction
            if adj.index(cur_char) == 1
              # index 1 in the adjacency means the key is shifted, 0 means unshifted: A vs a, % vs 5, etc.
              # for example, 'q' is adjacent to the entry '2@'. @ is shifted w/ index 1, 2 is unshifted.
              shifted_count += 1
            end
            if last_direction != found_direction
              # adding a turn is correct even in the initial case when last_direction is null:
              # every spatial pattern starts with a turn.
              turns += 1
              last_direction = found_direction
            end
            break
          end
        end
      end
      # if the current pattern continued, extend j and try to grow again
      if found
        j += 1
      else
        # otherwise push the pattern discovered so far, if any...
        if j - i > 2 # don't consider length 1 or 2 chains.
          result << Match.new(
            :pattern => 'spatial',
            :i => i,
            :j => j-1,
            :token => password[i...j],
            :graph => graph_name,
            :turns => turns,
            :shifted_count => shifted_count
          )
        end
        # ...and then start a new search for the rest of the password.
        i = j
        break
      end
    end
  end
  result
end