Changed from LGPL'd base64 lib to more permissive one

tasks/http-server/base64.lua

@@ -1,42 +1,133 @@
--- Lua 5.1+ base64 v3.0 (c) 2009 by Alex Kloss <[email protected]>
--- licensed under the terms of the LGPL2
---
--- adapted by [email protected]
-
--- character table string
-local b='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
-
--- encoding
-local function enc(data)
-    return ((data:gsub('.', function(x) 
-        local r,b='',x:byte()
-        for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end
-        return r;
-    end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x)
-        if (#x < 6) then return '' end
-        local c=0
-        for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end
-        return b:sub(c+1,c+1)
-    end)..({ '', '==', '=' })[#data%3+1])
+-- This is the base64 implementation extracted from https://github.com/aiq/basexx with the necessary helper functions
+--[[
+                                  BaseXX license:
+---------------------------------------------------------------------------------------
+Copyright (c) 2013 aiq
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+]]--
+
+--------------------------------------------------------------------------------
+-- util functions
+--------------------------------------------------------------------------------
+
+local function divide_string( str, max, fillChar )
+   fillChar = fillChar or ""
+   local result = {}
+
+   local start = 1
+   for i = 1, #str do
+      if i % max == 0 then
+         table.insert( result, str:sub( start, i ) )
+         start = i + 1
+      elseif i == #str then
+         table.insert( result, str:sub( start, i ) )
+      end
+   end
+
+   return result
+end
+
+local function number_to_bit( num, length )
+   local bits = {}
+
+   while num > 0 do
+      local rest = math.floor( math.fmod( num, 2 ) )
+      table.insert( bits, rest )
+      num = ( num - rest ) / 2
+   end
+
+   while #bits < length do
+      table.insert( bits, "0" )
+   end
+
+   return string.reverse( table.concat( bits ) )
+end
+
+local function ignore_set( str, set )
+   if set then
+      str = str:gsub( "["..set.."]", "" )
+   end
+   return str
+end
+
+local function pure_from_bit( str )
+   return ( str:gsub( '........', function ( cc )
+               return string.char( tonumber( cc, 2 ) )
+            end ) )
+end
+
+--------------------------------------------------------------------------------
+local basexx = {}
+--------------------------------------------------------------------------------
+-- generic function to decode and encode base32/base64
+--------------------------------------------------------------------------------
+
+local function from_basexx( str, alphabet, bits )
+   local result = {}
+   for i = 1, #str do
+      local c = string.sub( str, i, i )
+      if c ~= '=' then
+         local index = string.find( alphabet, c, 1, true )
+         if not index then
+            return nil, c
+         end
+         table.insert( result, number_to_bit( index - 1, bits ) )
+      end
+   end
+
+   local value = table.concat( result )
+   local pad = #value % 8
+   return pure_from_bit( string.sub( value, 1, #value - pad ) )
 end
+
+local function to_basexx( str, alphabet, bits, pad )
+   local bitString = basexx.to_bit( str )
+
+   local chunks = divide_string( bitString, bits )
+   local result = {}
+   for key,value in ipairs( chunks ) do
+      if ( #value < bits ) then
+         value = value .. string.rep( '0', bits - #value )
+      end
+      local pos = tonumber( value, 2 ) + 1
+      table.insert( result, alphabet:sub( pos, pos ) )
+   end
+
+   table.insert( result, pad )
+   return table.concat( result )   
+end
+--------------------------------------------------------------------------------
+-- base64 decode and encode function
+--------------------------------------------------------------------------------
+
+local base64Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"..
+                       "abcdefghijklmnopqrstuvwxyz"..
+                       "0123456789+/"
+local base64PadMap = { "", "==", "=" }
 
--- decoding
-local function dec(data)
-    data = string.gsub(data, '[^'..b..'=]', '')
-    return (data:gsub('.', function(x)
-        if (x == '=') then return '' end
-        local r,f='',(b:find(x)-1)
-        for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end
-        return r;
-    end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x)
-        if (#x ~= 8) then return '' end
-        local c=0
-        for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(7-i) or 0) end
-        return string.char(c)
-    end))
-end
-
-return {
-	encode = enc,
-	decode = dec,
-}    
+function basexx.from_base64( str, ignore )
+   str = ignore_set( str, ignore )
+   return from_basexx( str, base64Alphabet, 6 )
+end
+
+function basexx.to_base64( str )
+   return to_basexx( str, base64Alphabet, 6, base64PadMap[ #str % 3 + 1 ] )
+end
+---------------------------------------------------------------
+return {encode = basexx.to_base64, decode = basexx.from_base64}