Software / code / prosody
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util/x509.lua @ 5745:a1b0cfebeeba
certmanager: Set our own default cipher string, which includes only ciphers regarded as 'HIGH' strength (by OpenSSL). In particular this disables RC4.
| author | Matthew Wild <mwild1@gmail.com> |
|---|---|
| date | Sat, 13 Jul 2013 13:15:24 +0100 |
| parent | 4825:5fdc36bd866c |
| child | 5845:c48f717c2fd6 |
| rev | line source |
|---|---|
| 3651 | 1 -- Prosody IM |
| 2 -- Copyright (C) 2010 Matthew Wild | |
| 3 -- Copyright (C) 2010 Paul Aurich | |
| 4 -- | |
| 5 -- This project is MIT/X11 licensed. Please see the | |
| 6 -- COPYING file in the source package for more information. | |
| 7 -- | |
| 8 | |
| 9 -- TODO: I feel a fair amount of this logic should be integrated into Luasec, | |
| 10 -- so that everyone isn't re-inventing the wheel. Dependencies on | |
| 11 -- IDN libraries complicate that. | |
| 12 | |
| 13 | |
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14 -- [TLS-CERTS] - http://tools.ietf.org/html/rfc6125 |
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15 -- [XMPP-CORE] - http://tools.ietf.org/html/rfc6120 |
| 3651 | 16 -- [SRV-ID] - http://tools.ietf.org/html/rfc4985 |
| 17 -- [IDNA] - http://tools.ietf.org/html/rfc5890 | |
| 18 -- [LDAP] - http://tools.ietf.org/html/rfc4519 | |
| 19 -- [PKIX] - http://tools.ietf.org/html/rfc5280 | |
| 20 | |
| 21 local nameprep = require "util.encodings".stringprep.nameprep; | |
| 22 local idna_to_ascii = require "util.encodings".idna.to_ascii; | |
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util.x509: "certverification" -> "x509".
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23 local log = require "util.logger".init("x509"); |
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24 local pairs, ipairs = pairs, ipairs; |
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25 local s_format = string.format; |
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26 local t_insert = table.insert; |
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27 local t_concat = table.concat; |
| 3651 | 28 |
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29 module "x509" |
| 3651 | 30 |
| 31 local oid_commonname = "2.5.4.3"; -- [LDAP] 2.3 | |
| 32 local oid_subjectaltname = "2.5.29.17"; -- [PKIX] 4.2.1.6 | |
| 33 local oid_xmppaddr = "1.3.6.1.5.5.7.8.5"; -- [XMPP-CORE] | |
| 34 local oid_dnssrv = "1.3.6.1.5.5.7.8.7"; -- [SRV-ID] | |
| 35 | |
| 36 -- Compare a hostname (possibly international) with asserted names | |
| 37 -- extracted from a certificate. | |
| 38 -- This function follows the rules laid out in | |
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39 -- sections 6.4.1 and 6.4.2 of [TLS-CERTS] |
| 3651 | 40 -- |
| 41 -- A wildcard ("*") all by itself is allowed only as the left-most label | |
| 42 local function compare_dnsname(host, asserted_names) | |
| 43 -- TODO: Sufficient normalization? Review relevant specs. | |
| 44 local norm_host = idna_to_ascii(host) | |
| 45 if norm_host == nil then | |
| 46 log("info", "Host %s failed IDNA ToASCII operation", host) | |
| 47 return false | |
| 48 end | |
| 49 | |
| 50 norm_host = norm_host:lower() | |
| 51 | |
| 52 local host_chopped = norm_host:gsub("^[^.]+%.", "") -- everything after the first label | |
| 53 | |
| 54 for i=1,#asserted_names do | |
| 55 local name = asserted_names[i] | |
| 56 if norm_host == name:lower() then | |
| 57 log("debug", "Cert dNSName %s matched hostname", name); | |
| 58 return true | |
| 59 end | |
| 60 | |
| 61 -- Allow the left most label to be a "*" | |
| 62 if name:match("^%*%.") then | |
| 63 local rest_name = name:gsub("^[^.]+%.", "") | |
| 64 if host_chopped == rest_name:lower() then | |
| 65 log("debug", "Cert dNSName %s matched hostname", name); | |
| 66 return true | |
| 67 end | |
| 68 end | |
| 69 end | |
| 70 | |
| 71 return false | |
| 72 end | |
| 73 | |
| 74 -- Compare an XMPP domain name with the asserted id-on-xmppAddr | |
| 75 -- identities extracted from a certificate. Both are UTF8 strings. | |
| 76 -- | |
| 77 -- Per [XMPP-CORE], matches against asserted identities don't include | |
| 78 -- wildcards, so we just do a normalize on both and then a string comparison | |
| 79 -- | |
| 80 -- TODO: Support for full JIDs? | |
| 81 local function compare_xmppaddr(host, asserted_names) | |
| 82 local norm_host = nameprep(host) | |
| 83 | |
| 84 for i=1,#asserted_names do | |
| 85 local name = asserted_names[i] | |
| 86 | |
| 87 -- We only want to match against bare domains right now, not | |
| 88 -- those crazy full-er JIDs. | |
| 89 if name:match("[@/]") then | |
| 90 log("debug", "Ignoring xmppAddr %s because it's not a bare domain", name) | |
| 91 else | |
| 92 local norm_name = nameprep(name) | |
| 93 if norm_name == nil then | |
| 94 log("info", "Ignoring xmppAddr %s, failed nameprep!", name) | |
| 95 else | |
| 96 if norm_host == norm_name then | |
| 97 log("debug", "Cert xmppAddr %s matched hostname", name) | |
| 98 return true | |
| 99 end | |
| 100 end | |
| 101 end | |
| 102 end | |
| 103 | |
| 104 return false | |
| 105 end | |
| 106 | |
| 107 -- Compare a host + service against the asserted id-on-dnsSRV (SRV-ID) | |
| 108 -- identities extracted from a certificate. | |
| 109 -- | |
| 110 -- Per [SRV-ID], the asserted identities will be encoded in ASCII via ToASCII. | |
| 111 -- Comparison is done case-insensitively, and a wildcard ("*") all by itself | |
| 112 -- is allowed only as the left-most non-service label. | |
| 113 local function compare_srvname(host, service, asserted_names) | |
| 114 local norm_host = idna_to_ascii(host) | |
| 115 if norm_host == nil then | |
| 116 log("info", "Host %s failed IDNA ToASCII operation", host); | |
| 117 return false | |
| 118 end | |
| 119 | |
| 120 -- Service names start with a "_" | |
| 121 if service:match("^_") == nil then service = "_"..service end | |
| 122 | |
| 123 norm_host = norm_host:lower(); | |
| 124 local host_chopped = norm_host:gsub("^[^.]+%.", "") -- everything after the first label | |
| 125 | |
| 126 for i=1,#asserted_names do | |
| 127 local asserted_service, name = asserted_names[i]:match("^(_[^.]+)%.(.*)"); | |
| 128 if service == asserted_service then | |
| 129 if norm_host == name:lower() then | |
| 130 log("debug", "Cert SRVName %s matched hostname", name); | |
| 131 return true; | |
| 132 end | |
| 133 | |
| 134 -- Allow the left most label to be a "*" | |
| 135 if name:match("^%*%.") then | |
| 136 local rest_name = name:gsub("^[^.]+%.", "") | |
| 137 if host_chopped == rest_name:lower() then | |
| 138 log("debug", "Cert SRVName %s matched hostname", name) | |
| 139 return true | |
| 140 end | |
| 141 end | |
| 142 if norm_host == name:lower() then | |
| 143 log("debug", "Cert SRVName %s matched hostname", name); | |
| 144 return true | |
| 145 end | |
| 146 end | |
| 147 end | |
| 148 | |
| 149 return false | |
| 150 end | |
| 151 | |
| 152 function verify_identity(host, service, cert) | |
| 153 local ext = cert:extensions() | |
| 154 if ext[oid_subjectaltname] then | |
| 155 local sans = ext[oid_subjectaltname]; | |
| 156 | |
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util.x509: Update references to published RFCs
Paul Aurich <paul@darkrain42.org>
parents:
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diff
changeset
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157 -- Per [TLS-CERTS] 6.3, 6.4.4, "a client MUST NOT seek a match for a |
| 3651 | 158 -- reference identifier if the presented identifiers include a DNS-ID |
| 159 -- SRV-ID, URI-ID, or any application-specific identifier types" | |
| 160 local had_supported_altnames = false | |
| 161 | |
| 162 if sans[oid_xmppaddr] then | |
| 163 had_supported_altnames = true | |
| 164 if compare_xmppaddr(host, sans[oid_xmppaddr]) then return true end | |
| 165 end | |
| 166 | |
| 167 if sans[oid_dnssrv] then | |
| 168 had_supported_altnames = true | |
| 169 -- Only check srvNames if the caller specified a service | |
| 170 if service and compare_srvname(host, service, sans[oid_dnssrv]) then return true end | |
| 171 end | |
| 172 | |
| 173 if sans["dNSName"] then | |
| 174 had_supported_altnames = true | |
| 175 if compare_dnsname(host, sans["dNSName"]) then return true end | |
| 176 end | |
| 177 | |
| 178 -- We don't need URIs, but [TLS-CERTS] is clear. | |
| 179 if sans["uniformResourceIdentifier"] then | |
| 180 had_supported_altnames = true | |
| 181 end | |
| 182 | |
| 183 if had_supported_altnames then return false end | |
| 184 end | |
| 185 | |
| 186 -- Extract a common name from the certificate, and check it as if it were | |
| 187 -- a dNSName subjectAltName (wildcards may apply for, and receive, | |
| 188 -- cat treats) | |
| 189 -- | |
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util.x509: Update references to published RFCs
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diff
changeset
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190 -- Per [TLS-CERTS] 1.8, a CN-ID is the Common Name from a cert subject |
| 3651 | 191 -- which has one and only one Common Name |
| 192 local subject = cert:subject() | |
| 193 local cn = nil | |
| 194 for i=1,#subject do | |
| 195 local dn = subject[i] | |
| 196 if dn["oid"] == oid_commonname then | |
| 197 if cn then | |
| 198 log("info", "Certificate has multiple common names") | |
| 199 return false | |
| 200 end | |
| 201 | |
| 202 cn = dn["value"]; | |
| 203 end | |
| 204 end | |
| 205 | |
| 206 if cn then | |
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207 -- Per [TLS-CERTS] 6.4.4, follow the comparison rules for dNSName SANs. |
| 3651 | 208 return compare_dnsname(host, { cn }) |
| 209 end | |
| 210 | |
| 211 -- If all else fails, well, why should we be any different? | |
| 212 return false | |
| 213 end | |
| 214 | |
| 215 return _M; |
