Mercurial > prosody-modules
view mod_pubsub_github/mod_pubsub_github.lua @ 5193:2bb29ece216b
mod_http_oauth2: Implement stateless dynamic client registration
Replaces previous explicit registration that required either the
additional module mod_adhoc_oauth2_client or manually editing the
database. That method was enough to have something to test with, but
would not probably not scale easily.
Dynamic client registration allows creating clients on the fly, which
may be even easier in theory.
In order to not allow basically unauthenticated writes to the database,
we implement a stateless model here.
per_host_key := HMAC(config -> oauth2_registration_key, hostname)
client_id := JWT { client metadata } signed with per_host_key
client_secret := HMAC(per_host_key, client_id)
This should ensure everything we need to know is part of the client_id,
allowing redirects etc to be validated, and the client_secret can be
validated with only the client_id and the per_host_key.
A nonce injected into the client_id JWT should ensure nobody can submit
the same client metadata and retrieve the same client_secret
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Fri, 03 Mar 2023 21:14:19 +0100 |
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