ryzom/client/data/gamedev/interfaces_v3/base64.lua

   1 --[[
   2
   3  base64 -- v1.5.1 public domain Lua base64 encoder/decoder
   4  no warranty implied; use at your own risk
   5
   6  Needs bit32.extract function. If not present it's implemented using BitOp
   7  or Lua 5.3 native bit operators. For Lua 5.1 fallbacks to pure Lua
   8  implementation inspired by Rici Lake's post:
   9    http://ricilake.blogspot.co.uk/2007/10/iterating-bits-in-lua.html
  10
  11  author: Ilya Kolbin (iskolbin@gmail.com)
  12  url: github.com/iskolbin/lbase64
  13
  14  COMPATIBILITY
  15
  16  Lua 5.1, 5.2, 5.3, LuaJIT
  17
  18  LICENSE
  19
  20  See end of file for license information.
  21
  22 --]]
  23
  24
  25 base64 = {}
  26
  27 local extract = _G.bit32 and _G.bit32.extract
  28 if not extract then
  29         if _G.bit then
  30                 local shl, shr, band = _G.bit.lshift, _G.bit.rshift, _G.bit.band
  31                 extract = function( v, from, width )
  32                         return band( shr( v, from ), shl( 1, width ) - 1 )
  33                 end
  34         elseif _G._VERSION >= "Lua 5.3" then
  35                 extract = load[[return function( v, from, width )
  36                         return ( v >> from ) & ((1 << width) - 1)
  37                 end]]()
  38         else
  39                 extract = function( v, from, width )
  40                         local w = 0
  41                         local flag = 2^from
  42                         for i = 0, width-1 do
  43                                 local flag2 = flag + flag
  44                                 if v % flag2 >= flag then
  45                                         w = w + 2^i
  46                                 end
  47                                 flag = flag2
  48                         end
  49                         return w
  50                 end
  51         end
  52 end
  53
  54
  55 function base64.makeencoder( s62, s63, spad )
  56         local encoder = {}
  57         for b64code, char in pairs{[0]='A','B','C','D','E','F','G','H','I','J',
  58                 'K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y',
  59                 'Z','a','b','c','d','e','f','g','h','i','j','k','l','m','n',
  60                 'o','p','q','r','s','t','u','v','w','x','y','z','0','1','2',
  61                 '3','4','5','6','7','8','9',s62 or '+',s63 or'/',spad or'='} do
  62                 encoder[b64code] = char:byte()
  63         end
  64         return encoder
  65 end
  66
  67 function base64.makedecoder( s62, s63, spad )
  68         local decoder = {}
  69         for b64code, charcode in pairs( base64.makeencoder( s62, s63, spad )) do
  70                 decoder[charcode] = b64code
  71         end
  72         return decoder
  73 end
  74
  75 local DEFAULT_ENCODER = base64.makeencoder()
  76 local DEFAULT_DECODER = base64.makedecoder()
  77
  78 local char, concat = string.char, table.concat
  79
  80 function base64.encode( str, encoder, usecaching )
  81         encoder = encoder or DEFAULT_ENCODER
  82         local t, k, n = {}, 1, #str
  83         local lastn = n % 3
  84         local cache = {}
  85         for i = 1, n-lastn, 3 do
  86                 local a, b, c = str:byte( i, i+2 )
  87                 local v = a*0x10000 + b*0x100 + c
  88                 local s
  89                 if usecaching then
  90                         s = cache[v]
  91                         if not s then
  92                                 s = char(encoder[extract(v,18,6)], encoder[extract(v,12,6)], encoder[extract(v,6,6)], encoder[extract(v,0,6)])
  93                                 cache[v] = s
  94                         end
  95                 else
  96                         s = char(encoder[extract(v,18,6)], encoder[extract(v,12,6)], encoder[extract(v,6,6)], encoder[extract(v,0,6)])
  97                 end
  98                 t[k] = s
  99                 k = k + 1
 100         end
 101         if lastn == 2 then
 102                 local a, b = str:byte( n-1, n )
 103                 local v = a*0x10000 + b*0x100
 104                 t[k] = char(encoder[extract(v,18,6)], encoder[extract(v,12,6)], encoder[extract(v,6,6)], encoder[64])
 105         elseif lastn == 1 then
 106                 local v = str:byte( n )*0x10000
 107                 t[k] = char(encoder[extract(v,18,6)], encoder[extract(v,12,6)], encoder[64], encoder[64])
 108         end
 109         return concat( t )
 110 end
 111
 112 function base64.decode( b64, decoder, usecaching )
 113         decoder = decoder or DEFAULT_DECODER
 114         local pattern = '[^%w%+%/%=]'
 115         if decoder then
 116                 local s62, s63
 117                 for charcode, b64code in pairs( decoder ) do
 118                         if b64code == 62 then s62 = charcode
 119                         elseif b64code == 63 then s63 = charcode
 120                         end
 121                 end
 122                 pattern = ('[^%%w%%%s%%%s%%=]'):format( char(s62), char(s63) )
 123         end
 124         b64 = b64:gsub( pattern, '' )
 125         local cache = usecaching and {}
 126         local t, k = {}, 1
 127         local n = #b64
 128         local padding = b64:sub(-2) == '==' and 2 or b64:sub(-1) == '=' and 1 or 0
 129         for i = 1, padding > 0 and n-4 or n, 4 do
 130                 local a, b, c, d = b64:byte( i, i+3 )
 131                 local s
 132                 if usecaching then
 133                         local v0 = a*0x1000000 + b*0x10000 + c*0x100 + d
 134                         s = cache[v0]
 135                         if not s then
 136                                 local v = decoder[a]*0x40000 + decoder[b]*0x1000 + decoder[c]*0x40 + decoder[d]
 137                                 s = char( extract(v,16,8), extract(v,8,8), extract(v,0,8))
 138                                 cache[v0] = s
 139                         end
 140                 else
 141                         local v = decoder[a]*0x40000 + decoder[b]*0x1000 + decoder[c]*0x40 + decoder[d]
 142                         s = char( extract(v,16,8), extract(v,8,8), extract(v,0,8))
 143                 end
 144                 t[k] = s
 145                 k = k + 1
 146         end
 147         if padding == 1 then
 148                 local a, b, c = b64:byte( n-3, n-1 )
 149                 local v = decoder[a]*0x40000 + decoder[b]*0x1000 + decoder[c]*0x40
 150                 t[k] = char( extract(v,16,8), extract(v,8,8))
 151         elseif padding == 2 then
 152                 local a, b = b64:byte( n-3, n-2 )
 153                 local v = decoder[a]*0x40000 + decoder[b]*0x1000
 154                 t[k] = char( extract(v,16,8))
 155         end
 156         return concat( t )
 157 end
 158
 159 return base64
 160
 161 --[[
 162 ------------------------------------------------------------------------------
 163 This software is available under 2 licenses -- choose whichever you prefer.
 164 ------------------------------------------------------------------------------
 165 ALTERNATIVE A - MIT License
 166 Copyright (c) 2018 Ilya Kolbin
 167 Permission is hereby granted, free of charge, to any person obtaining a copy of
 168 this software and associated documentation files (the "Software"), to deal in
 169 the Software without restriction, including without limitation the rights to
 170 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 171 of the Software, and to permit persons to whom the Software is furnished to do
 172 so, subject to the following conditions:
 173 The above copyright notice and this permission notice shall be included in all
 174 copies or substantial portions of the Software.
 175 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 176 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 177 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 178 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 179 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 180 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 181 SOFTWARE.
 182 ------------------------------------------------------------------------------
 183 ALTERNATIVE B - Public Domain (www.unlicense.org)
 184 This is free and unencumbered software released into the public domain.
 185 Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
 186 software, either in source code form or as a compiled binary, for any purpose,
 187 commercial or non-commercial, and by any means.
 188 In jurisdictions that recognize copyright laws, the author or authors of this
 189 software dedicate any and all copyright interest in the software to the public
 190 domain. We make this dedication for the benefit of the public at large and to
 191 the detriment of our heirs and successors. We intend this dedication to be an
 192 overt act of relinquishment in perpetuity of all present and future rights to
 193 this software under copyright law.
 194 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 195 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 196 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 197 AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 198 ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 199 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 200 ------------------------------------------------------------------------------
 201 --]]