Mercurial > prosody-modules
view mod_pubsub_github/mod_pubsub_github.lua @ 4651:8231774f5bfd
mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8
The `body:sub()` call risks splitting the string in the middle of a
multi-byte UTF-8 sequence. This should have been caught by util.stanza
validation, but that would have caused some havoc, at the very least causing
the notification to not be sent.
There have been no reports of this happening. Likely because this module
isn't widely deployed among users with languages that use many longer UTF-8
sequences.
The util.encodings.utf8.valid() function is O(n) where only the last
sequence really needs to be checked, but it's in C and expected to be fast.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sun, 22 Aug 2021 13:22:59 +0200 |
parents | 3bece2db869c |
children |
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module:depends("http"); local st = require "util.stanza"; local json = require "util.json"; local hashes = require "util.hashes"; local from_hex = require "util.hex".from; local hmacs = { sha1 = hashes.hmac_sha1; sha256 = hashes.hmac_sha256; sha384 = hashes.hmac_sha384; sha512 = hashes.hmac_sha512; }; local pubsub_service = module:depends("pubsub").service; -- configuration local default_node = module:get_option("github_node", "github"); local node_prefix = module:get_option_string("github_node_prefix", "github/"); local node_mapping = module:get_option_string("github_node_mapping"); local github_actor = module:get_option_string("github_actor") or true; local github_secret = module:get_option("github_secret"); -- validation assert(github_secret, "Please set 'github_secret'"); local error_mapping = { ["forbidden"] = 403; ["item-not-found"] = 404; ["internal-server-error"] = 500; ["conflict"] = 409; }; local function verify_signature(secret, body, signature) if not signature then return false; end local algo, digest = signature:match("^([^=]+)=(%x+)"); if not algo then return false; end local hmac = hmacs[algo]; if not algo then return false; end return hmac(secret, body) == from_hex(digest); end function handle_POST(event) local request, response = event.request, event.response; if not verify_signature(github_secret, request.body, request.headers.x_hub_signature) then module:log("debug", "Signature validation failed"); return 401; end local data = json.decode(request.body); if not data then response.status_code = 400; return "Invalid JSON. From you of all people..."; end local node = default_node; if node_mapping then node = node_prefix .. data.repository[node_mapping]; end local github_event = request.headers.x_github_event or data.object_kind; if not github_event and data.commits then github_event = "push"; -- curl? end module:log("debug", "Handling '%s' event: \n%s\n", github_event, tostring(request.body)); if github_event == "push" then for _, commit in ipairs(data.commits) do local ok, err = pubsub_service:publish(node, github_actor, commit.id, st.stanza("item", { id = commit.id, xmlns = "http://jabber.org/protocol/pubsub" }) :tag("entry", { xmlns = "http://www.w3.org/2005/Atom" }) :tag("id"):text(commit.id):up() :tag("title"):text(commit.message:match("^[^\r\n]*")):up() :tag("summary"):text(("Commit to %s by %s: %s"):format(data.repository.name, commit.author.name, commit.message:match("^[^\r\n]*"))):up() :tag("content"):text(commit.message):up() :tag("link", { rel = "alternate", href = commit.url }):up() :tag("published"):text(commit.author.date):up() :tag("author") :tag("name"):text(commit.author.name):up() :tag("email"):text(commit.author.email):up() :up() ); if not ok then return error_mapping[err] or 500; end end elseif github_event then module:log("debug", "Unsupported Github event %q", github_event); return 501; end response.status_code = 202; return "Thank you Github!"; end module:provides("http", { route = { POST = handle_POST; }; }); if not node_mapping then function module.load() if not pubsub_service.nodes[default_node] then local ok, err = pubsub_service:create(default_node, true); if not ok then module:log("error", "Error creating node: %s", err); else module:log("debug", "Node %q created", default_node); end end end end