Mercurial > prosody-modules
changeset 2332:c2cf5b40b66d
mod_http_upload_external: Variant of mod_http_upload that delegates HTTP handling to other server using signed URLs
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Thu, 13 Oct 2016 18:57:15 +0200 (2016-10-13) |
parents | 611a787e6d08 |
children | f86478a02b25 |
files | mod_http_upload_external/mod_http_upload_external.lua |
diffstat | 1 files changed, 80 insertions(+), 0 deletions(-) [+] |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mod_http_upload_external/mod_http_upload_external.lua Thu Oct 13 18:57:15 2016 +0200 @@ -0,0 +1,80 @@ +-- mod_http_upload_external +-- +-- Copyright (C) 2015-2016 Kim Alvefur +-- +-- This file is MIT/X11 licensed. +-- + +-- imports +local st = require"util.stanza"; +local uuid = require"util.uuid".generate; +local http = require "util.http"; +local dataform = require "util.dataforms".new; +local HMAC = require "util.hashes".hmac_sha256; + +-- config +local file_size_limit = module:get_option_number(module.name .. "_file_size_limit", 100 * 1024 * 1024); -- 100 MB +local base_url = assert(module:get_option_string(module.name .. "_base_url"), module.name .. "_base_url is a required option"); +local secret = assert(module:get_option_string(module.name .. "_secret"), module.name .. "_secret is a required option"); + +-- depends +module:depends("disco"); + +-- namespace +local xmlns_http_upload = "urn:xmpp:http:upload"; + +-- identity and feature advertising +module:add_identity("store", "file", module:get_option_string("name", "HTTP File Upload")) +module:add_feature(xmlns_http_upload); + +module:add_extension(dataform { + { name = "FORM_TYPE", type = "hidden", value = xmlns_http_upload }, + { name = "max-file-size", type = "text-single" }, +}:form({ ["max-file-size"] = tostring(file_size_limit) }, "result")); + +local function magic_crypto_dust(random, filename, filesize) + local message = string.format("%s/%s %d", random, filename, filesize); + local digest = HMAC(secret, message, true); + random, filename = http.urlencode(random), http.urlencode(filename); + return base_url .. random .. "/" .. filename, "?v=" .. digest; +end + +-- hooks +module:hook("iq/host/"..xmlns_http_upload..":request", function (event) + local stanza, origin = event.stanza, event.origin; + local request = stanza.tags[1]; + -- local clients only + if origin.type ~= "c2s" then + module:log("debug", "Request for upload slot from a %s", origin.type); + origin.send(st.error_reply(stanza, "cancel", "not-authorized")); + return true; + end + -- validate + local filename = request:get_child_text("filename"); + if not filename or filename:find("/") then + module:log("debug", "Filename %q not allowed", filename or ""); + origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid filename")); + return true; + end + local filesize = tonumber(request:get_child_text("size")); + if not filesize then + module:log("debug", "Missing file size"); + origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing or invalid file size")); + return true; + elseif filesize > file_size_limit then + module:log("debug", "File too large (%d > %d)", filesize, file_size_limit); + origin.send(st.error_reply(stanza, "modify", "not-acceptable", "File too large", + st.stanza("file-too-large", {xmlns=xmlns_http_upload}) + :tag("max-size"):text(tostring(file_size_limit)))); + return true; + end + local reply = st.reply(stanza); + reply:tag("slot", { xmlns = xmlns_http_upload }); + local random = uuid(); + local get_url, verify = magic_crypto_dust(random, filename, filesize); + reply:tag("get"):text(get_url):up(); + reply:tag("put"):text(get_url .. verify):up(); + module:log("info", "Handed out upload slot %s to %s@%s", get_url, origin.username, origin.host); + origin.send(reply); + return true; +end);