mod_http_oauth2: Strip unknown extra fields from client registration We shouldn't sign things we don't understand! RFC 7591 section-2 states: > The authorization server MUST ignore any client metadata sent by the > client that it does not understand (for instance, by silently removing > unknown metadata from the client's registration record during > processing). Prevents grandfathering in of unvalidated data that might become used later, especially since the 'additionalProperties' schema keyword was removed in 698fef74ce53

local base64_encode = require"util.encodings".base64.encode;
local random_bytes = require"util.random".bytes;

local b64url = { ["+"] = "-", ["/"] = "_", ["="] = "" };
local function random_resource()
	return base64_encode(random_bytes(8)):gsub("[+/=]", b64url);
end

module:hook("pre-resource-bind", function (event)
	event.resource = random_resource();
end);