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