90 lines
2.4 KiB
Lua
90 lines
2.4 KiB
Lua
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-----------------------------------------------------------------------------
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-- MIME support for the Lua language.
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-- Author: Diego Nehab
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-- Conforming to RFCs 2045-2049
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-----------------------------------------------------------------------------
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-----------------------------------------------------------------------------
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-- Declare module and import dependencies
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-----------------------------------------------------------------------------
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local base = _G
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local ltn12 = require("ltn12")
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local mime = require("mime.core")
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local io = require("io")
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local string = require("string")
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local _M = mime
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-- encode, decode and wrap algorithm tables
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local encodet, decodet, wrapt = {},{},{}
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_M.encodet = encodet
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_M.decodet = decodet
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_M.wrapt = wrapt
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-- creates a function that chooses a filter by name from a given table
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local function choose(table)
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return function(name, opt1, opt2)
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if base.type(name) ~= "string" then
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name, opt1, opt2 = "default", name, opt1
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end
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local f = table[name or "nil"]
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if not f then
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base.error("unknown key (" .. base.tostring(name) .. ")", 3)
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else return f(opt1, opt2) end
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end
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end
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-- define the encoding filters
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encodet['base64'] = function()
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return ltn12.filter.cycle(_M.b64, "")
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end
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encodet['quoted-printable'] = function(mode)
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return ltn12.filter.cycle(_M.qp, "",
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(mode == "binary") and "=0D=0A" or "\r\n")
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end
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-- define the decoding filters
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decodet['base64'] = function()
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return ltn12.filter.cycle(_M.unb64, "")
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end
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decodet['quoted-printable'] = function()
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return ltn12.filter.cycle(_M.unqp, "")
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end
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local function format(chunk)
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if chunk then
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if chunk == "" then return "''"
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else return string.len(chunk) end
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else return "nil" end
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end
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-- define the line-wrap filters
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wrapt['text'] = function(length)
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length = length or 76
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return ltn12.filter.cycle(_M.wrp, length, length)
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end
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wrapt['base64'] = wrapt['text']
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wrapt['default'] = wrapt['text']
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wrapt['quoted-printable'] = function()
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return ltn12.filter.cycle(_M.qpwrp, 76, 76)
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end
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-- function that choose the encoding, decoding or wrap algorithm
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_M.encode = choose(encodet)
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_M.decode = choose(decodet)
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_M.wrap = choose(wrapt)
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-- define the end-of-line normalization filter
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function _M.normalize(marker)
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return ltn12.filter.cycle(_M.eol, 0, marker)
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end
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-- high level stuffing filter
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function _M.stuff()
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return ltn12.filter.cycle(_M.dot, 2)
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end
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return _M
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