Module: Philiprehberger::Password::Strength

Defined in:
lib/philiprehberger/password/strength.rb

Constant Summary collapse

LABELS = 
{
  0 => :terrible,
  1 => :weak,
  2 => :fair,
  3 => :strong,
  4 => :excellent
}.freeze

Class Method Summary collapse

Class Method Details

.compute(password) ⇒ Object 



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# File 'lib/philiprehberger/password/strength.rb', line 14

def self.compute(password)
  pwd = password.to_s
  return { score: 0, label: :terrible, entropy: 0.0 } if pwd.empty?

  ent = entropy(pwd)

  s = if ent < 28
        0
      elsif ent < 36
        1
      elsif ent < 60
        2
      elsif ent < 80
        3
      else
        4
      end

  { score: s, label: LABELS[s], entropy: ent.round(2) }
end

.entropy(password) ⇒ Object 



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# File 'lib/philiprehberger/password/strength.rb', line 35

def self.entropy(password)
  pwd = password.to_s
  return 0.0 if pwd.empty?

  pool = 0
  pool += 26 if pwd.match?(/[a-z]/)
  pool += 26 if pwd.match?(/[A-Z]/)
  pool += 10 if pwd.match?(/\d/)
  pool += 33 if pwd.match?(/[^a-zA-Z\d]/)

  pwd.length * Math.log2([pool, 1].max)
end