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Diffstat (limited to 'util/certverification.lua')
| -rw-r--r-- | util/certverification.lua | 211 |
1 files changed, 0 insertions, 211 deletions
diff --git a/util/certverification.lua b/util/certverification.lua deleted file mode 100644 index d323f4b4..00000000 --- a/util/certverification.lua +++ /dev/null @@ -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; |