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util/x509.lua @ 4814:474684c07a3a
Rename plugins/s2s/ to plugins/mod_s2s/
author | Matthew Wild <mwild1@gmail.com> |
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date | Fri, 04 May 2012 00:05:15 +0100 |
parent | 4486:f04db5e7e90d |
child | 4825:5fdc36bd866c |
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-- 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/rfc6125 -- [XMPP-CORE] - http://tools.ietf.org/html/rfc6120 -- [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("x509"); local pairs, ipairs = pairs, ipairs; local s_format = string.format; local t_insert = table.insert; local t_concat = table.concat; module "x509" 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 6.4.1 and 6.4.2 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] 6.3, 6.4.4, "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] 1.8, 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] 6.4.4, 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 -- TODO Rename? Split out subroutines? -- Also, this is probably openssl specific, what TODO about that? function genx509san(hosts, config, certhosts, raw) -- recive config through that or some better way? local function utf8string(s) -- This is how we tell openssl not to encode UTF-8 strings as Latin1 return s_format("FORMAT:UTF8,UTF8:%s", s); end local function ia5string(s) return s_format("IA5STRING:%s", s); end local function dnsname(t, host) t_insert(t.DNS, idna_to_ascii(host)); end local function srvname(t, host, service) t_insert(t.otherName, s_format("%s;%s", oid_dnssrv, ia5string("_" .. service .."." .. idna_to_ascii(host)))); end local function xmppAddr(t, host) t_insert(t.otherName, s_format("%s;%s", oid_xmppaddr, utf8string(host))); end ----------------------------- local san = { DNS = {}; otherName = {}; }; local sslsanconf = { }; for i = 1,#certhosts do local certhost = certhosts[i]; for name, host in pairs(hosts) do if name == certhost or name:sub(-1-#certhost) == "."..certhost then dnsname(san, name); --print(name .. "#component_module: " .. (config.get(name, "core", "component_module") or "nil")); if config.get(name, "core", "component_module") == nil then srvname(san, name, "xmpp-client"); end --print(name .. "#anonymous_login: " .. tostring(config.get(name, "core", "anonymous_login"))); if not (config.get(name, "core", "anonymous_login") or config.get(name, "core", "authentication") == "anonymous") then srvname(san, name, "xmpp-server"); end xmppAddr(san, name); end end end for t, n in pairs(san) do for i = 1,#n do t_insert(sslsanconf, s_format("%s.%d = %s", t, i -1, n[i])); end end return raw and sslsanconf or t_concat(sslsanconf, "\n"); end function baseconf() return { req = { distinguished_name = "distinguished_name", req_extensions = "v3_extensions", x509_extensions = "v3_extensions", prompt = "no", }, distinguished_name = { commonName = "example.com", countryName = "GB", localityName = "The Internet", organizationName = "Your Organisation", organizationalUnitName = "XMPP Department", emailAddress = "xmpp@example.com", }, v3_extensions = { basicConstraints = "CA:FALSE", keyUsage = "digitalSignature,keyEncipherment", extendedKeyUsage = "serverAuth,clientAuth", subjectAltName = "@subject_alternative_name", }, subject_alternative_name = { }, } end function serialize_conf(conf) local s = ""; for k, t in pairs(conf) do s = s .. ("[%s]\n"):format(k); if t[1] then for i, v in ipairs(t) do s = s .. ("%s\n"):format(v); end else for k, v in pairs(t) do s = s .. ("%s = %s\n"):format(k, v); end end s = s .. "\n"; end return s; end return _M;