LiveCode Forums.

Code: Select all

function crypt passwd, data
  put length(passwd) into passwd_length
  put length(data) into data_length
  repeat with x=0 to 256
    put "" into thebox[x]
    put "" into key[x]
  end repeat
  put "" into cipher
  
  repeat with i=1 to 256
    put char (i mod passwd_length) of passwd into q
    --put q into key[i]   anyone know why this line has been commented out?
    put chartonum(q) into key[i]
    put i into thebox[i]
  end repeat
  
  put 1 into j
  repeat with i=1 to 256
    put (j + thebox[i] + key[i]) mod 256 into j
    put thebox[i] into tmp
    put thebox[j] into thebox[i]
    put tmp into thebox[j]
  end repeat
  
  put 1 into a
  put 1 into j
  repeat with i=1 to data_length
    put (a + 1) mod 256 into a
    put (j + thebox[a]) mod 256 into j
    put thebox[a] into tmp
    put thebox[j] into thebox[a]
    put tmp into thebox[j]
    put thebox[((thebox[a] + thebox[j]) mod 256)] into k
    put chartonum(char i of data) into v
    put v into r
    put k into s
    put r bitxor s into q
    put numtochar(q) into hex
    put hex after cipher
  end repeat
  return cipher
  
end crypt

function dcrypt passwd, data
  put crypt(passwd, data) into z
  return z
end dcrypt

function tohexadecimal charval
  put chartonum(charval) into theVal
  put theVal mod 16 into lsd
  if lsd>9 then
    put toHex(lsd) into lsd
    end if
  put trunc(theVal/16) into msd
  if msd>9 then
    put toHex(msd) into msd
  end if
  return msd & lsd
end tohexadecimal

function toHex digits
    if digits=10 then put "A" into tmp
    if digits=11 then put "B" into tmp
    if digits=12 then put "C" into tmp
    if digits=13 then put "D" into tmp
    if digits=14 then put "E" into tmp
    if digits=15 then put "F" into tmp
    return tmp
end toHex