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-rw-r--r--core/s2smanager.lua40
-rw-r--r--net/server_event.lua4
-rw-r--r--plugins/mod_console.lua4
-rw-r--r--plugins/mod_dialback.lua14
-rw-r--r--plugins/mod_saslauth.lua132
-rw-r--r--util/certverification.lua211
6 files changed, 399 insertions, 6 deletions
diff --git a/core/s2smanager.lua b/core/s2smanager.lua
index c4a94682..be5c04fc 100644
--- a/core/s2smanager.lua
+++ b/core/s2smanager.lua
@@ -27,6 +27,7 @@ local modulemanager = require "core.modulemanager";
local st = require "stanza";
local stanza = st.stanza;
local nameprep = require "util.encodings".stringprep.nameprep;
+local cert_verify_identity = require "util.certverification".verify_identity;
local fire_event = prosody.events.fire_event;
local uuid_gen = require "util.uuid".generate;
@@ -373,16 +374,44 @@ function session_open_stream(session, from, to)
from=from, to=to, version='1.0', ["xml:lang"]='en'}):top_tag());
end
+local function check_cert_status(session)
+ local conn = session.conn:socket()
+ local cert = conn:getpeercertificate()
+
+ if cert then
+ local chain_valid, err = conn:getpeerchainvalid()
+ if not chain_valid then
+ session.cert_chain_status = "invalid";
+ (session.log or log)("debug", "certificate chain validation result: %s", err);
+ else
+ session.cert_chain_status = "valid";
+
+ local host = session.direction == "incoming" and session.from_host or session.to_host
+
+ -- We'll go ahead and verify the asserted identity if the
+ -- connecting server specified one.
+ if host then
+ if cert_verify_identity(host, "xmpp-server", cert) then
+ session.cert_identity_status = "valid"
+ else
+ session.cert_identity_status = "invalid"
+ end
+ end
+ end
+ end
+end
+
function streamopened(session, attr)
local send = session.sends2s;
-- TODO: #29: SASL/TLS on s2s streams
session.version = tonumber(attr.version) or 0;
+ -- TODO: Rename session.secure to session.encrypted
if session.secure == false then
session.secure = true;
end
-
+
if session.direction == "incoming" then
-- Send a reply stream header
session.to_host = attr.to and nameprep(attr.to);
@@ -407,6 +436,9 @@ function streamopened(session, attr)
return;
end
end
+
+ if session.secure and not session.cert_chain_status then check_cert_status(session); end
+
send("<?xml version='1.0'?>");
send(stanza("stream:stream", { xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.to_host, to=session.from_host, version=(session.version > 0 and "1.0" or nil) }):top_tag());
@@ -426,7 +458,9 @@ function streamopened(session, attr)
-- If we are just using the connection for verifying dialback keys, we won't try and auth it
if not attr.id then error("stream response did not give us a streamid!!!"); end
session.streamid = attr.id;
-
+
+ if session.secure and not session.cert_chain_status then check_cert_status(session); end
+
-- Send unauthed buffer
-- (stanzas which are fine to send before dialback)
-- Note that this is *not* the stanza queue (which
@@ -490,9 +524,11 @@ function make_authenticated(session, host)
elseif session.type == "s2sin_unauthed" then
session.type = "s2sin";
if host then
+ if not session.hosts[host] then session.hosts[host] = {}; end
session.hosts[host].authed = true;
end
elseif session.type == "s2sin" and host then
+ if not session.hosts[host] then session.hosts[host] = {}; end
session.hosts[host].authed = true;
else
return false;
diff --git a/net/server_event.lua b/net/server_event.lua
index 1db78041..122d80fc 100644
--- a/net/server_event.lua
+++ b/net/server_event.lua
@@ -361,6 +361,10 @@ do
end
end
+ function interface_mt:socket()
+ return self.conn
+ end
+
function interface_mt:server()
return self._server or self;
end
diff --git a/plugins/mod_console.lua b/plugins/mod_console.lua
index c84cd5ac..6c1c8fd9 100644
--- a/plugins/mod_console.lua
+++ b/plugins/mod_console.lua
@@ -498,7 +498,7 @@ function def_env.s2s:show(match_jid)
for remotehost, session in pairs(host_session.s2sout) do
if (not match_jid) or remotehost:match(match_jid) or host:match(match_jid) then
count_out = count_out + 1;
- print(" "..host.." -> "..remotehost..(session.secure and " (encrypted)" or "")..(session.compressed and " (compressed)" or ""));
+ print(" "..host.." -> "..remotehost..(session.cert_identity_status == "valid" and " (secure)" or "")..(session.secure and " (encrypted)" or "")..(session.compressed and " (compressed)" or ""));
if session.sendq then
print(" There are "..#session.sendq.." queued outgoing stanzas for this connection");
end
@@ -535,7 +535,7 @@ function def_env.s2s:show(match_jid)
-- Pft! is what I say to list comprehensions
or (session.hosts and #array.collect(keys(session.hosts)):filter(subhost_filter)>0)) then
count_in = count_in + 1;
- print(" "..host.." <- "..(session.from_host or "(unknown)")..(session.secure and " (encrypted)" or "")..(session.compressed and " (compressed)" or ""));
+ print(" "..host.." <- "..(session.from_host or "(unknown)")..(session.cert_identity_status == "valid" and " (secure)" or "")..(session.secure and " (encrypted)" or "")..(session.compressed and " (compressed)" or ""));
if session.type == "s2sin_unauthed" then
print(" Connection not yet authenticated");
end
diff --git a/plugins/mod_dialback.lua b/plugins/mod_dialback.lua
index e1fd5a42..a8923e27 100644
--- a/plugins/mod_dialback.lua
+++ b/plugins/mod_dialback.lua
@@ -132,9 +132,19 @@ module:hook("stanza/jabber:server:dialback:result", function(event)
end
end);
+module:hook_stanza("urn:ietf:params:xml:ns:xmpp-sasl", "failure", function (origin, stanza)
+ if origin.external_auth == "failed" then
+ module:log("debug", "SASL EXTERNAL failed, falling back to dialback");
+ s2s_initiate_dialback(origin);
+ return true;
+ end
+end, 100);
+
module:hook_stanza(xmlns_stream, "features", function (origin, stanza)
- s2s_initiate_dialback(origin);
- return true;
+ if not origin.external_auth or origin.external_auth == "failed" then
+ s2s_initiate_dialback(origin);
+ return true;
+ end
end, 100);
-- Offer dialback to incoming hosts
diff --git a/plugins/mod_saslauth.lua b/plugins/mod_saslauth.lua
index c6ead31a..37b2720b 100644
--- a/plugins/mod_saslauth.lua
+++ b/plugins/mod_saslauth.lua
@@ -11,8 +11,11 @@
local st = require "util.stanza";
local sm_bind_resource = require "core.sessionmanager".bind_resource;
local sm_make_authenticated = require "core.sessionmanager".make_authenticated;
+local s2s_make_authenticated = require "core.s2smanager".make_authenticated;
local base64 = require "util.encodings".base64;
+local cert_verify_identity = require "util.certverification".verify_identity;
+
local nodeprep = require "util.encodings".stringprep.nodeprep;
local usermanager_get_sasl_handler = require "core.usermanager".get_sasl_handler;
local t_concat, t_insert = table.concat, table.insert;
@@ -91,8 +94,123 @@ local function sasl_process_cdata(session, stanza)
return true;
end
+module:hook_stanza(xmlns_sasl, "success", function (session, stanza)
+ if session.type ~= "s2sout_unauthed" or session.external_auth ~= "attempting" then return; end
+ module:log("debug", "SASL EXTERNAL with %s succeeded", session.to_host);
+ session.external_auth = "succeeded"
+ session:reset_stream();
+
+ local default_stream_attr = {xmlns = "jabber:server", ["xmlns:stream"] = "http://etherx.jabber.org/streams",
+ ["xmlns:db"] = 'jabber:server:dialback', version = "1.0", to = session.to_host, from = session.from_host};
+ session.sends2s("<?xml version='1.0'?>");
+ session.sends2s(st.stanza("stream:stream", default_stream_attr):top_tag());
+
+ s2s_make_authenticated(session, session.to_host);
+ return true;
+end)
+
+module:hook_stanza(xmlns_sasl, "failure", function (session, stanza)
+ if session.type ~= "s2sout_unauthed" or session.external_auth ~= "attempting" then return; end
+
+ module:log("info", "SASL EXTERNAL with %s failed", session.to_host)
+ -- TODO: Log the failure reason
+ session.external_auth = "failed"
+end, 500)
+
+module:hook_stanza(xmlns_sasl, "failure", function (session, stanza)
+ -- TODO: Dialback wasn't loaded. Do something useful.
+end, 90)
+
+module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza)
+ if session.type ~= "s2sout_unauthed" or not session.secure then return; end
+
+ local mechanisms = stanza:get_child("mechanisms", xmlns_sasl)
+ if mechanisms then
+ for mech in mechanisms:childtags() do
+ if mech[1] == "EXTERNAL" then
+ module:log("debug", "Initiating SASL EXTERNAL with %s", session.to_host);
+ local reply = st.stanza("auth", {xmlns = xmlns_sasl, mechanism = "EXTERNAL"});
+ reply:text(base64.encode(session.from_host))
+ session.sends2s(reply)
+ session.external_auth = "attempting"
+ return true
+ end
+ end
+ end
+end, 150);
+
+local function s2s_external_auth(session, stanza)
+ local mechanism = stanza.attr.mechanism;
+
+ if not session.secure then
+ if mechanism == "EXTERNAL" then
+ session.sends2s(build_reply("failure", "encryption-required"))
+ else
+ session.sends2s(build_reply("failure", "invalid-mechanism"))
+ end
+ return true;
+ end
+
+ if mechanism ~= "EXTERNAL" or session.cert_chain_status ~= "valid" then
+ session.sends2s(build_reply("failure", "invalid-mechanism"))
+ return true;
+ end
+
+ local text = stanza[1]
+ if not text then
+ session.sends2s(build_reply("failure", "malformed-request"))
+ return true
+ end
+
+ -- Either the value is "=" and we've already verified the external
+ -- cert identity, or the value is a string and either matches the
+ -- from_host (
+
+ text = base64.decode(text)
+ if not text then
+ session.sends2s(build_reply("failure", "incorrect-encoding"))
+ return true;
+ end
+
+ if session.cert_identity_status == "valid" then
+ if text ~= "" and text ~= session.from_host then
+ session.sends2s(build_reply("failure", "invalid-authzid"))
+ return true
+ end
+ else
+ if text == "" then
+ session.sends2s(build_reply("failure", "invalid-authzid"))
+ return true
+ end
+
+ local cert = session.conn:socket():getpeercertificate()
+ if (cert_verify_identity(text, "xmpp-server", cert)) then
+ session.cert_identity_status = "valid"
+ else
+ session.cert_identity_status = "invalid"
+ session.sends2s(build_reply("failure", "invalid-authzid"))
+ return true
+ end
+ end
+
+ session.external_auth = "succeeded"
+
+ if not session.from_host then
+ session.from_host = text;
+ end
+ session.sends2s(build_reply("success"))
+ module:log("info", "Accepting SASL EXTERNAL identity from %s", text or session.from_host);
+ s2s_make_authenticated(session, text or session.from_host)
+ session:reset_stream();
+ return true
+end
+
module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:auth", function(event)
local session, stanza = event.origin, event.stanza;
+ if session.type == "s2sin_unauthed" then
+ return s2s_external_auth(session, stanza)
+ end
+
if session.type ~= "c2s_unauthed" then return; end
if session.sasl_handler and session.sasl_handler.selected then
@@ -168,6 +286,20 @@ module:hook("stream-features", function(event)
end
end);
+module:hook("s2s-stream-features", function(event)
+ local origin, features = event.origin, event.features;
+ if origin.secure and origin.type == "s2sin_unauthed" then
+ -- Offer EXTERNAL if chain is valid and either we didn't validate
+ -- the identity or it passed.
+ if origin.cert_chain_status == "valid" and origin.cert_identity_status ~= "invalid" then --TODO: Configurable
+ module:log("debug", "Offering SASL EXTERNAL")
+ features:tag("mechanisms", { xmlns = xmlns_sasl })
+ :tag("mechanism"):text("EXTERNAL")
+ :up():up();
+ end
+ end
+end);
+
module:hook("iq/self/urn:ietf:params:xml:ns:xmpp-bind:bind", function(event)
local origin, stanza = event.origin, event.stanza;
local resource;
diff --git a/util/certverification.lua b/util/certverification.lua
new file mode 100644
index 00000000..d323f4b4
--- /dev/null
+++ b/util/certverification.lua
@@ -0,0 +1,211 @@
+-- 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;
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-03 10:50:18 +0000