diff -r 323169f229fa -r 0731e5432baa util/certverification.lua
--- a/util/certverification.lua	Tue Dec 14 18:54:55 2010 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,211 +0,0 @@
--- Prosody IM
--- Copyright (C) 2010 Matthew Wild
--- Copyright (C) 2010 Paul Aurich
---
--- This project is MIT/X11 licensed. Please see the
--- COPYING file in the source package for more information.
---
-
--- TODO: I feel a fair amount of this logic should be integrated into Luasec,
--- so that everyone isn't re-inventing the wheel.  Dependencies on
--- IDN libraries complicate that.
-
-
--- [TLS-CERTS] - http://tools.ietf.org/html/draft-saintandre-tls-server-id-check-10
--- [XMPP-CORE] - http://tools.ietf.org/html/draft-ietf-xmpp-3920bis-18
--- [SRV-ID]    - http://tools.ietf.org/html/rfc4985
--- [IDNA]      - http://tools.ietf.org/html/rfc5890
--- [LDAP]      - http://tools.ietf.org/html/rfc4519
--- [PKIX]      - http://tools.ietf.org/html/rfc5280
-
-local nameprep = require "util.encodings".stringprep.nameprep;
-local idna_to_ascii = require "util.encodings".idna.to_ascii;
-local log = require "util.logger".init("certverification");
-
-module "certverification"
-
-local oid_commonname = "2.5.4.3"; -- [LDAP] 2.3
-local oid_subjectaltname = "2.5.29.17"; -- [PKIX] 4.2.1.6
-local oid_xmppaddr = "1.3.6.1.5.5.7.8.5"; -- [XMPP-CORE]
-local oid_dnssrv   = "1.3.6.1.5.5.7.8.7"; -- [SRV-ID]
-
--- Compare a hostname (possibly international) with asserted names
--- extracted from a certificate.
--- This function follows the rules laid out in
--- sections 4.4.1 and 4.4.2 of [TLS-CERTS]
---
--- A wildcard ("*") all by itself is allowed only as the left-most label
-local function compare_dnsname(host, asserted_names)
-	-- TODO: Sufficient normalization?  Review relevant specs.
-	local norm_host = idna_to_ascii(host)
-	if norm_host == nil then
-		log("info", "Host %s failed IDNA ToASCII operation", host)
-		return false
-	end
-
-	norm_host = norm_host:lower()
-
-	local host_chopped = norm_host:gsub("^[^.]+%.", "") -- everything after the first label
-
-	for i=1,#asserted_names do
-		local name = asserted_names[i]
-		if norm_host == name:lower() then
-			log("debug", "Cert dNSName %s matched hostname", name);
-			return true
-		end
-
-		-- Allow the left most label to be a "*"
-		if name:match("^%*%.") then
-			local rest_name = name:gsub("^[^.]+%.", "")
-			if host_chopped == rest_name:lower() then
-				log("debug", "Cert dNSName %s matched hostname", name);
-				return true
-			end
-		end
-	end
-
-	return false
-end
-
--- Compare an XMPP domain name with the asserted id-on-xmppAddr
--- identities extracted from a certificate.  Both are UTF8 strings.
---
--- Per [XMPP-CORE], matches against asserted identities don't include
--- wildcards, so we just do a normalize on both and then a string comparison
---
--- TODO: Support for full JIDs?
-local function compare_xmppaddr(host, asserted_names)
-	local norm_host = nameprep(host)
-
-	for i=1,#asserted_names do
-		local name = asserted_names[i]
-
-		-- We only want to match against bare domains right now, not
-		-- those crazy full-er JIDs.
-		if name:match("[@/]") then
-			log("debug", "Ignoring xmppAddr %s because it's not a bare domain", name)
-		else
-			local norm_name = nameprep(name)
-			if norm_name == nil then
-				log("info", "Ignoring xmppAddr %s, failed nameprep!", name)
-			else
-				if norm_host == norm_name then
-					log("debug", "Cert xmppAddr %s matched hostname", name)
-					return true
-				end
-			end
-		end
-	end
-
-	return false
-end
-
--- Compare a host + service against the asserted id-on-dnsSRV (SRV-ID)
--- identities extracted from a certificate.
---
--- Per [SRV-ID], the asserted identities will be encoded in ASCII via ToASCII.
--- Comparison is done case-insensitively, and a wildcard ("*") all by itself
--- is allowed only as the left-most non-service label.
-local function compare_srvname(host, service, asserted_names)
-	local norm_host = idna_to_ascii(host)
-	if norm_host == nil then
-		log("info", "Host %s failed IDNA ToASCII operation", host);
-		return false
-	end
-
-	-- Service names start with a "_"
-	if service:match("^_") == nil then service = "_"..service end
-
-	norm_host = norm_host:lower();
-	local host_chopped = norm_host:gsub("^[^.]+%.", "") -- everything after the first label
-
-	for i=1,#asserted_names do
-		local asserted_service, name = asserted_names[i]:match("^(_[^.]+)%.(.*)");
-		if service == asserted_service then
-			if norm_host == name:lower() then
-				log("debug", "Cert SRVName %s matched hostname", name);
-				return true;
-			end
-
-			-- Allow the left most label to be a "*"
-			if name:match("^%*%.") then
-				local rest_name = name:gsub("^[^.]+%.", "")
-				if host_chopped == rest_name:lower() then
-					log("debug", "Cert SRVName %s matched hostname", name)
-					return true
-				end
-			end
-			if norm_host == name:lower() then
-				log("debug", "Cert SRVName %s matched hostname", name);
-				return true
-			end
-		end
-	end
-
-	return false
-end
-
-function verify_identity(host, service, cert)
-	local ext = cert:extensions()
-	if ext[oid_subjectaltname] then
-		local sans = ext[oid_subjectaltname];
-
-		-- Per [TLS-CERTS] 4.3, 4.4.4, "a client MUST NOT seek a match for a
-		-- reference identifier if the presented identifiers include a DNS-ID
-		-- SRV-ID, URI-ID, or any application-specific identifier types"
-		local had_supported_altnames = false
-
-		if sans[oid_xmppaddr] then
-			had_supported_altnames = true
-			if compare_xmppaddr(host, sans[oid_xmppaddr]) then return true end
-		end
-
-		if sans[oid_dnssrv] then
-			had_supported_altnames = true
-			-- Only check srvNames if the caller specified a service
-			if service and compare_srvname(host, service, sans[oid_dnssrv]) then return true end
-		end
-
-		if sans["dNSName"] then
-			had_supported_altnames = true
-			if compare_dnsname(host, sans["dNSName"]) then return true end
-		end
-
-		-- We don't need URIs, but [TLS-CERTS] is clear.
-		if sans["uniformResourceIdentifier"] then
-			had_supported_altnames = true
-		end
-
-		if had_supported_altnames then return false end
-	end
-
-	-- Extract a common name from the certificate, and check it as if it were
-	-- a dNSName subjectAltName (wildcards may apply for, and receive,
-	-- cat treats)
-	--
-	-- Per [TLS-CERTS] 1.5, a CN-ID is the Common Name from a cert subject
-	-- which has one and only one Common Name
-	local subject = cert:subject()
-	local cn = nil
-	for i=1,#subject do
-		local dn = subject[i]
-		if dn["oid"] == oid_commonname then
-			if cn then
-				log("info", "Certificate has multiple common names")
-				return false
-			end
-
-			cn = dn["value"];
-		end
-	end
-
-	if cn then
-		-- Per [TLS-CERTS] 4.4.4, follow the comparison rules for dNSName SANs.
-		return compare_dnsname(host, { cn })
-	end
-
-	-- If all else fails, well, why should we be any different?
-	return false
-end
-
-return _M;