Class: JWA::Support::PBKDF2

Inherits:
Object
  • Object
show all
Defined in:
lib/jwa/support/pbkdf2.rb

Instance Method Summary collapse

Constructor Details

#initialize(hash) ⇒ PBKDF2

Returns a new instance of PBKDF2.



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# File 'lib/jwa/support/pbkdf2.rb', line 4

def initialize(hash)
  @hash = hash
end

Instance Method Details

#calculate_block(block_num, salt, password, iterations) ⇒ Object 



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# File 'lib/jwa/support/pbkdf2.rb', line 24

def calculate_block(block_num, salt, password, iterations)
  u = prf(salt + [block_num].pack('N'), password)
  ret = u

  2.upto(iterations) do
    u = prf(u, password)
    ret = xor(ret, u)
  end

  ret
end

#run(password, salt, iterations, key_length = nil) ⇒ Object 



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# File 'lib/jwa/support/pbkdf2.rb', line 12

def run(password, salt, iterations, key_length = nil)
  key_length ||= @hash.size

  blocks_needed = (key_length / @hash.size.to_f).ceil

  v = 1.upto(blocks_needed).map do |block_num|
    calculate_block(block_num, salt, password, iterations)
  end.join

  v[0...key_length]
end

#run_hex(password, salt, iterations, key_length = nil) ⇒ Object 



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# File 'lib/jwa/support/pbkdf2.rb', line 8

def run_hex(password, salt, iterations, key_length = nil)
  run(password, salt, iterations, key_length).unpack('H*').first
end