prosody-modules
f3e452b43cfe
mod_s2s_auth_posh/mod_s2s_auth_posh.lua

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mod_s2s_auth_posh/mod_s2s_auth_posh.lua @ 3198:f3e452b43cfe

mod_s2s_auth_posh: PKIX over Secure HTTP
author Kim Alvefur <zash@zash.se>
date Wed, 21 May 2014 23:01:47 +0200
child 3199:cb7c24305ed2
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3197:f6a14cdc531b 3198:f3e452b43cfe
1 -- Copyright (C) 2013 - 2014 Tobias Markmann
2 -- This file is MIT/X11 licensed.
3 --
4 -- Implements authentication via POSH (PKIX over Secure HTTP)
5 -- http://tools.ietf.org/html/draft-miller-posh-03
6 --
7 module:set_global();
8 --local https = require 'ssl.https'
9 --local http = require "socket.http";
10 local json = require 'util.json'
11 local serialization = require 'util.serialization'
12
13 local nameprep = require "util.encodings".stringprep.nameprep;
14 local to_unicode = require "util.encodings".idna.to_unicode;
15 local cert_verify_identity = require "util.x509".verify_identity;
16 local der2pem = require"util.x509".der2pem;
17 local base64 = require"util.encodings".base64;
18
19 local function posh_lookup(host_session, resume)
20 -- do nothing if posh info already exists
21 if host_session.posh ~= nil then return end
22
23 (host_session.log or module._log)("debug", "DIRECTION: %s", tostring(host_session.direction));
24
25 local target_host = false;
26 if host_session.direction == "incoming" then
27 target_host = host_session.from_host;
28 elseif host_session.direction == "outgoing" then
29 target_host = host_session.to_host;
30 end
31
32 local url = "https://"..target_host.."/.well-known/posh._xmpp-server._tcp.json"
33
34 (host_session.log or module._log)("debug", "Request POSH information for %s", tostring(target_host));
35 local request = http.request(url, nil, function(response, code, req)
36 (host_session.log or module._log)("debug", "Received POSH response");
37 local jwk = json.decode(response);
38 if not jwk then
39 (host_session.log or module._log)("error", "POSH response is not valid JSON!");
40 (host_session.log or module._log)("debug", tostring(response));
41 end
42 host_session.posh = {};
43 host_session.posh.jwk = jwk;
44 resume()
45 end)
46 return true;
47 end
48
49 function module.add_host(module)
50 local function on_new_s2s(event)
51 local host_session = event.origin;
52 if host_session.type == "s2sout" or host_session.type == "s2sin" or host_session.posh ~= nil then return end -- Already authenticated
53
54 host_session.log("debug", "Pausing connection until POSH lookup is completed");
55 host_session.conn:pause()
56 local function resume()
57 host_session.log("debug", "POSH lookup completed, resuming connection");
58 host_session.conn:resume()
59 end
60 if not posh_lookup(host_session, resume) then
61 resume();
62 end
63 end
64
65 -- New outgoing connections
66 module:hook("stanza/http://etherx.jabber.org/streams:features", on_new_s2s, 501);
67 module:hook("s2sout-authenticate-legacy", on_new_s2s, 200);
68
69 -- New incoming connections
70 module:hook("s2s-stream-features", on_new_s2s, 10);
71
72 module:hook("s2s-authenticated", function(event)
73 local session = event.session;
74 if session.posh and not session.secure then
75 -- Bogus replies should trigger this path
76 -- How does this interact with Dialback?
77 session:close({
78 condition = "policy-violation",
79 text = "Secure server-to-server communication is required but was not "
80 ..((session.direction == "outgoing" and "offered") or "used")
81 });
82 return false;
83 end
84 -- Cleanup
85 session.posh = nil;
86 end);
87 end
88
89 -- Do POSH authentication
90 module:hook("s2s-check-certificate", function(event)
91 local session, cert = event.session, event.cert;
92 (session.log or module._log)("info", "Trying POSH authentication.");
93 -- if session.cert_identity_status ~= "valid" and session.posh then
94 if session.posh then
95 local target_host = event.host;
96
97 local jwk = session.posh.jwk;
98
99 local connection_certs = session.conn:socket():getpeerchain();
100
101 local x5c_table = jwk.keys[1].x5c;
102
103 local wire_cert = connection_certs[1];
104 local jwk_cert = ssl.x509.load(der2pem(base64.decode(x5c_table[1])));
105
106 if (wire_cert and jwk_cert and
107 wire_cert:digest("sha1") == jwk_cert:digest("sha1")) then
108 session.cert_chain_status = "valid";
109 session.cert_identity_status = "valid";
110 (session.log or module._log)("debug", "POSH authentication succeeded!");
111 return true;
112 else
113 (session.log or module._log)("debug", "POSH authentication failed!");
114 (session.log or module._log)("debug", "(top wire sha1 vs top jwk sha1) = (%s vs %s)", wire_cert:digest("sha1"), jwk_cert:digest("sha1"));
115 return false;
116 end
117 end
118 end);