Class: Zxcvbn::Matchers::L33t Private

Inherits:
Object
  • Object
show all
Includes:
CaseHelpers
Defined in:
lib/zxcvbn/matchers/l33t.rb,
sig/zxcvbn/matchers/l33t.rbs

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Matches dictionary words after substituting common l33t-speak character replacements (e.g. "@" for "a", "3" for "e").

Constant Summary collapse

L33T_TABLE =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

Mapping from plain letter to the l33t characters that can represent it.

Returns:

  • (Hash[String, Array[String]]) 
{
  'a' => ['4', '@'].freeze,
  'b' => ['8'].freeze,
  'c' => ['(', '{', '[', '<'].freeze,
  'e' => ['3'].freeze,
  'g' => ['6', '9'].freeze,
  'i' => ['1', '!', '|'].freeze,
  'l' => ['1', '|', '7'].freeze,
  'o' => ['0'].freeze,
  's' => ['$', '5'].freeze,
  't' => ['+', '7'].freeze,
  'x' => ['%'].freeze,
  'z' => ['2'].freeze
}.freeze

Instance Method Summary collapse

Methods included from CaseHelpers

downcase_preserving_length, #self?.downcase_preserving_length

Constructor Details

#initialize(dictionary_matchers) ⇒ L33t

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of L33t.

Parameters:

  • dictionary_matchers (Array<Dictionary>) —

    matchers to run against substituted passwords



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# File 'lib/zxcvbn/matchers/l33t.rb', line 29

def initialize(dictionary_matchers)
  @dictionary_matchers = dictionary_matchers
end

Instance Method Details

#dedup(subs) ⇒ Array[untyped]

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Parameters:

  • subs (Array[untyped])

Returns:

  • (Array[untyped]) 


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# File 'lib/zxcvbn/matchers/l33t.rb', line 129

def dedup(subs)
  deduped = []
  seen = Set.new
  subs.each do |sub|
    # Sort and convert to hash for consistent comparison
    sorted_sub = sub.sort.to_h
    unless seen.include?(sorted_sub)
      seen.add(sorted_sub)
      deduped << sub
    end
  end
  deduped
end

#find_substitutions(subs, table, keys) ⇒ Array[untyped]

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Parameters:

  • subs (Array[untyped])
  • table (Hash[String, Array[String]])
  • keys (Array[String])

Returns:

  • (Array[untyped]) 


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# File 'lib/zxcvbn/matchers/l33t.rb', line 105

def find_substitutions(subs, table, keys)
  return subs if keys.empty?

  first_key = keys[0]
  rest_keys = keys[1..]
  next_subs = []
  table[first_key].each do |l33t_char|
    subs.each do |sub|
      dup_l33t_index = sub.find_index { |pair| pair[0] == l33t_char }

      if dup_l33t_index.nil?
        next_subs << (sub + [[l33t_char, first_key]])
      else
        sub_alternative = sub.dup
        sub_alternative[dup_l33t_index, 1] = [[l33t_char, first_key]]
        next_subs << sub
        next_subs << sub_alternative
      end
    end
  end
  subs = dedup(next_subs)
  find_substitutions(subs, table, rest_keys)
end

#l33t_subs(table) ⇒ Array<Hash{String => String}>

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Enumerates all possible substitution combinations for the given l33t subtable.

Parameters:

  • table (Hash{String => Array<String>}) —

    relevant l33t subtable

Returns:

  • (Array<Hash{String => String}>) —

    list of substitution maps to try



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# File 'lib/zxcvbn/matchers/l33t.rb', line 83

def l33t_subs(table)
  keys = table.keys
  subs = [[]]
  subs = find_substitutions(subs, table, keys)
  subs.map(&:to_h)
end

#matches(password) ⇒ Array<MatchBuilder>

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns l33t-substituted dictionary matches found in password.

Parameters:

  • password (String)

Returns:

  • (Array<MatchBuilder>) —

    matches with pattern "dictionary" and l33t: true



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# File 'lib/zxcvbn/matchers/l33t.rb', line 37

def matches(password)
  matches = []
  lowercased_password = downcase_preserving_length(password)
  relevent_subtable = relevent_l33t_subtable(lowercased_password)

  # Early bailout: if no l33t characters present, return empty matches
  return matches if relevent_subtable.empty?

  combinations_to_try = l33t_subs(relevent_subtable)
  combinations_to_try.each do |substitution|
    @dictionary_matchers.each do |matcher|
      subbed_password = translate(lowercased_password, substitution)
      matcher.matches(subbed_password).each do |match|
        process_match(match, password, substitution, matches)
      end
    end
  end
  matches
end

#process_match(match, password, substitution, matches) ⇒ void

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

This method returns an undefined value.

Parameters:



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# File 'lib/zxcvbn/matchers/l33t.rb', line 92

def process_match(match, password, substitution, matches)
  length = match.j - match.i + 1
  token = password.slice(match.i, length)
  return if token.downcase == match.matched_word.downcase

  match_substitutions = substitution.select { |s, _| token.include?(s) }
  match.l33t = true
  match.token = token
  match.sub = match_substitutions
  match.sub_display = match_substitutions.map { |k, v| "#{k} -> #{v}" }.join(', ')
  matches << match
end

#relevent_l33t_subtable(password) ⇒ Hash{String => Array<String>}

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns the subset of L33T_TABLE whose l33t characters appear in password.

Parameters:

  • password (String) —

    lowercased password

Returns:

  • (Hash{String => Array<String>}) 


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# File 'lib/zxcvbn/matchers/l33t.rb', line 70

def relevent_l33t_subtable(password)
  filtered = {}
  L33T_TABLE.each do |letter, subs|
    relevent_subs = subs.select { |s| password.include?(s) }
    filtered[letter] = relevent_subs unless relevent_subs.empty?
  end
  filtered
end

#translate(password, sub) ⇒ String

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a copy of password with each character replaced according to sub.

Parameters:

  • password (String)
  • sub (Hash{String => String}) —

    character substitution map

Returns:

  • (String) 


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# File 'lib/zxcvbn/matchers/l33t.rb', line 62

def translate(password, sub)
  password.gsub(Regexp.union(sub.keys), sub)
end