Module:Base64: Difference between revisions
Jump to navigation
Jump to search
Content added Content deleted
No edit summary |
No edit summary |
||
| Line 20: | Line 20: | ||
yesno(encode, false) |
yesno(encode, false) |
||
return "Sorry, I gave up that time" |
|||
local base64 = {} |
|||
local extract = _G.bit32 and _G.bit32.extract -- Lua 5.2/Lua 5.3 in compatibility mode |
|||
if not extract then |
|||
if _G.bit then -- LuaJIT |
|||
local shl, shr, band = _G.bit.lshift, _G.bit.rshift, _G.bit.band |
|||
extract = function( v, from, width ) |
|||
return band( shr( v, from ), shl( 1, width ) - 1 ) |
|||
end |
|||
elseif _G._VERSION == "Lua 5.1" then |
|||
extract = function( v, from, width ) |
|||
local w = 0 |
|||
local flag = 2^from |
|||
for i = 0, width-1 do |
|||
local flag2 = flag + flag |
|||
if v % flag2 >= flag then |
|||
w = w + 2^i |
|||
end |
|||
flag = flag2 |
|||
end |
|||
return w |
|||
end |
|||
else -- Lua 5.3+ |
|||
extract = load[[return function( v, from, width ) |
|||
return ( v >> from ) & ((1 << width) - 1) |
|||
end]]() |
|||
end |
|||
end |
|||
function base64.makeencoder( s62, s63, spad ) |
|||
local encoder = {} |
|||
for b64code, char in pairs{[0]='A','B','C','D','E','F','G','H','I','J', |
|||
'K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y', |
|||
'Z','a','b','c','d','e','f','g','h','i','j','k','l','m','n', |
|||
'o','p','q','r','s','t','u','v','w','x','y','z','0','1','2', |
|||
'3','4','5','6','7','8','9',s62 or '+',s63 or'/',spad or'='} do |
|||
encoder[b64code] = char:byte() |
|||
end |
|||
return encoder |
|||
end |
|||
function base64.makedecoder( s62, s63, spad ) |
|||
local decoder = {} |
|||
for b64code, charcode in pairs( base64.makeencoder( s62, s63, spad )) do |
|||
decoder[charcode] = b64code |
|||
end |
|||
return decoder |
|||
end |
|||
local DEFAULT_ENCODER = base64.makeencoder() |
|||
local DEFAULT_DECODER = base64.makedecoder() |
|||
local char, concat = string.char, table.concat |
|||
function base64.encode( str, encoder, usecaching ) |
|||
encoder = encoder or DEFAULT_ENCODER |
|||
local t, k, n = {}, 1, #str |
|||
local lastn = n % 3 |
|||
local cache = {} |
|||
for i = 1, n-lastn, 3 do |
|||
local a, b, c = str:byte( i, i+2 ) |
|||
local v = a*0x10000 + b*0x100 + c |
|||
local s |
|||
if usecaching then |
|||
s = cache[v] |
|||
if not s then |
|||
s = char(encoder[extract(v,18,6)], encoder[extract(v,12,6)], encoder[extract(v,6,6)], encoder[extract(v,0,6)]) |
|||
cache[v] = s |
|||
end |
|||
else |
|||
s = char(encoder[extract(v,18,6)], encoder[extract(v,12,6)], encoder[extract(v,6,6)], encoder[extract(v,0,6)]) |
|||
end |
|||
t[k] = s |
|||
k = k + 1 |
|||
end |
|||
if lastn == 2 then |
|||
local a, b = str:byte( n-1, n ) |
|||
local v = a*0x10000 + b*0x100 |
|||
t[k] = char(encoder[extract(v,18,6)], encoder[extract(v,12,6)], encoder[extract(v,6,6)], encoder[64]) |
|||
elseif lastn == 1 then |
|||
local v = str:byte( n )*0x10000 |
|||
t[k] = char(encoder[extract(v,18,6)], encoder[extract(v,12,6)], encoder[64], encoder[64]) |
|||
end |
|||
return concat( t ) |
|||
end |
|||
function base64.decode( b64, decoder, usecaching ) |
|||
decoder = decoder or DEFAULT_DECODER |
|||
local pattern = '[^%w%+%/%=]' |
|||
if decoder then |
|||
local s62, s63 |
|||
for charcode, b64code in pairs( decoder ) do |
|||
if b64code == 62 then s62 = charcode |
|||
elseif b64code == 63 then s63 = charcode |
|||
end |
|||
end |
|||
pattern = ('[^%%w%%%s%%%s%%=]'):format( char(s62), char(s63) ) |
|||
end |
|||
b64 = b64:gsub( pattern, '' ) |
|||
local cache = usecaching and {} |
|||
local t, k = {}, 1 |
|||
local n = #b64 |
|||
local padding = b64:sub(-2) == '==' and 2 or b64:sub(-1) == '=' and 1 or 0 |
|||
for i = 1, padding > 0 and n-4 or n, 4 do |
|||
local a, b, c, d = b64:byte( i, i+3 ) |
|||
local s |
|||
if usecaching then |
|||
local v0 = a*0x1000000 + b*0x10000 + c*0x100 + d |
|||
s = cache[v0] |
|||
if not s then |
|||
local v = decoder[a]*0x40000 + decoder[b]*0x1000 + decoder[c]*0x40 + decoder[d] |
|||
s = char( extract(v,16,8), extract(v,8,8), extract(v,0,8)) |
|||
cache[v0] = s |
|||
end |
|||
else |
|||
local v = decoder[a]*0x40000 + decoder[b]*0x1000 + decoder[c]*0x40 + decoder[d] |
|||
s = char( extract(v,16,8), extract(v,8,8), extract(v,0,8)) |
|||
end |
|||
t[k] = s |
|||
k = k + 1 |
|||
end |
|||
if padding == 1 then |
|||
local a, b, c = b64:byte( n-3, n-1 ) |
|||
local v = decoder[a]*0x40000 + decoder[b]*0x1000 + decoder[c]*0x40 |
|||
t[k] = char( extract(v,16,8), extract(v,8,8)) |
|||
elseif padding == 2 then |
|||
local a, b = b64:byte( n-3, n-2 ) |
|||
local v = decoder[a]*0x40000 + decoder[b]*0x1000 |
|||
t[k] = char( extract(v,16,8)) |
|||
end |
|||
return concat( t ) |
|||
end |
|||
if (encode == true) then |
|||
local encoded = base64.encode(data) |
|||
return encoded |
|||
else |
|||
local decoded = base64.decode(data) |
|||
return encoded |
|||
end |
|||
end |
end |
||
Latest revision as of 15:48, 14 January 2021
Documentation for this module may be created at Module:Base64/doc
-- Made by [[User:Celeste]] - Licensed under GPLv3
local p = {}
local yesno = require('Module:Yesno') -- invoke Yesno
local b='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/' -- You will need this for encoding/decoding
function p.base64(frame)
local args
local data
local encode
if frame == mw.getCurrentFrame() then
args = frame.args
else
args = frame
end
data = frame.args.data
encode = frame.args.encode
yesno(encode, false)
return "Sorry, I gave up that time"
end
return p