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 8

def initialize(graphs)
  @graphs = graphs
end

Instance Method Details

#matches(password) ⇒ Object 



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# File 'lib/zxcvbn/matchers/spatial.rb', line 12

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 20

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
          next unless 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
      # 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.slice(i, j - i),
            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