PBKDF2 encryption

Do you know the PBKDF2 encryption?
It's the encryption used on Wi-Fi, Mac and more systems. You may read something here: http://en.wikipedia.org/wiki/PBKDF2


refaktor wrote a script to use PBKDF2 encryption, and so you can use it with Rebol!

The source code is here: https://github.com/refaktor/Rebol2-PBKDF2/blob/master/pbkdf2.r

REBOL []
pbkdf2: context [
unsigned-to-binary: func [n [number!] /rev][
  if n > (2 ** 31 - 1) [n: n - (2 ** 32)]
  n: load join "#{" [form to-hex to-integer n "}"]
  either rev [head reverse n][n]
]
calc-sha1: func [pwd salt count key-len /string
  /local hash-len block-len output i j ] [
  hash-len: length? to-string checksum/secure ""
  block-cnt: round/ceiling (key-len / hash-len)
  output: copy #{}
  repeat i block-cnt [
  last: join salt unsigned-to-binary i
  last: xorsum: checksum/key last pwd
  repeat j (count - 1) [
    xorsum: (xorsum xor (last: checksum/key last pwd))
  ]
  output: join output xorsum
  ]
  output: copy/part output key-len
  either string [trim/with enbase/base output 16 #"^/" ] [output ]
]
]