core/certmanager.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9 local softreq = require"util.dependencies".softreq;
  10 local ssl = softreq"ssl";
  11 if not ssl then
  12         return {
  13                 create_context = function ()
  14                         return nil, "LuaSec (required for encryption) was not found";
  15                 end;
  16                 reload_ssl_config = function () end;
  17         }
  18 end
  19
  20 local configmanager = require "core.configmanager";
  21 local log = require "util.logger".init("certmanager");
  22 local ssl_context = ssl.context or softreq"ssl.context";
  23 local ssl_newcontext = ssl.newcontext;
  24 local new_config = require"util.sslconfig".new;
  25 local stat = require "lfs".attributes;
  26
  27 local tonumber, tostring = tonumber, tostring;
  28 local pairs = pairs;
  29 local t_remove = table.remove;
  30 local type = type;
  31 local io_open = io.open;
  32 local select = select;
  33
  34 local prosody = prosody;
  35 local resolve_path = require"util.paths".resolve_relative_path;
  36 local config_path = prosody.paths.config or ".";
  37
  38 local luasec_major, luasec_minor = ssl._VERSION:match("^(%d+)%.(%d+)");
  39 local luasec_version = tonumber(luasec_major) * 100 + tonumber(luasec_minor);
  40 local luasec_has = softreq"ssl.config" or {
  41         algorithms = {
  42                 ec = luasec_version >= 5;
  43         };
  44         capabilities = {
  45                 curves_list = luasec_version >= 7;
  46         };
  47         options = {
  48                 cipher_server_preference = luasec_version >= 2;
  49                 no_ticket = luasec_version >= 4;
  50                 no_compression = luasec_version >= 5;
  51                 single_dh_use = luasec_version >= 2;
  52                 single_ecdh_use = luasec_version >= 2;
  53         };
  54 };
  55
  56 local _ENV = nil;
  57 -- luacheck: std none
  58
  59 -- Global SSL options if not overridden per-host
  60 local global_ssl_config = configmanager.get("*", "ssl");
  61
  62 local global_certificates = configmanager.get("*", "certificates") or "certs";
  63
  64 local crt_try = { "", "/%s.crt", "/%s/fullchain.pem", "/%s.pem", };
  65 local key_try = { "", "/%s.key", "/%s/privkey.pem",   "/%s.pem", };
  66
  67 local function find_cert(user_certs, name)
  68         local certs = resolve_path(config_path, user_certs or global_certificates);
  69         log("debug", "Searching %s for a key and certificate for %s...", certs, name);
  70         for i = 1, #crt_try do
  71                 local crt_path = certs .. crt_try[i]:format(name);
  72                 local key_path = certs .. key_try[i]:format(name);
  73
  74                 if stat(crt_path, "mode") == "file" then
  75                         if key_path:sub(-4) == ".crt" then
  76                                 key_path = key_path:sub(1, -4) .. "key";
  77                                 if stat(key_path, "mode") == "file" then
  78                                         log("debug", "Selecting certificate %s with key %s for %s", crt_path, key_path, name);
  79                                         return { certificate = crt_path, key = key_path };
  80                                 end
  81                         elseif stat(key_path, "mode") == "file" then
  82                                 log("debug", "Selecting certificate %s with key %s for %s", crt_path, key_path, name);
  83                                 return { certificate = crt_path, key = key_path };
  84                         end
  85                 end
  86         end
  87         log("debug", "No certificate/key found for %s", name);
  88 end
  89
  90 local function find_host_cert(host)
  91         if not host then return nil; end
  92         return find_cert(configmanager.get(host, "certificate"), host) or find_host_cert(host:match("%.(.+)$"));
  93 end
  94
  95 local function find_service_cert(service, port)
  96         local cert_config = configmanager.get("*", service.."_certificate");
  97         if type(cert_config) == "table" then
  98                 cert_config = cert_config[port] or cert_config.default;
  99         end
 100         return find_cert(cert_config, service);
 101 end
 102
 103 -- Built-in defaults
 104 local core_defaults = {
 105         capath = "/etc/ssl/certs";
 106         depth = 9;
 107         protocol = "tlsv1+";
 108         verify = "none";
 109         options = {
 110                 cipher_server_preference = luasec_has.options.cipher_server_preference;
 111                 no_ticket = luasec_has.options.no_ticket;
 112                 no_compression = luasec_has.options.no_compression and configmanager.get("*", "ssl_compression") ~= true;
 113                 single_dh_use = luasec_has.options.single_dh_use;
 114                 single_ecdh_use = luasec_has.options.single_ecdh_use;
 115         };
 116         verifyext = { "lsec_continue", "lsec_ignore_purpose" };
 117         curve = luasec_has.algorithms.ec and not luasec_has.capabilities.curves_list and "secp384r1";
 118         curveslist = {
 119                 "X25519",
 120                 "P-384",
 121                 "P-256",
 122                 "P-521",
 123         };
 124         ciphers = {      -- Enabled ciphers in order of preference:
 125                 "HIGH+kEECDH", -- Ephemeral Elliptic curve Diffie-Hellman key exchange
 126                 "HIGH+kEDH",   -- Ephemeral Diffie-Hellman key exchange, if a 'dhparam' file is set
 127                 "HIGH",        -- Other "High strength" ciphers
 128                                -- Disabled cipher suites:
 129                 "!PSK",        -- Pre-Shared Key - not used for XMPP
 130                 "!SRP",        -- Secure Remote Password - not used for XMPP
 131                 "!3DES",       -- 3DES - slow and of questionable security
 132                 "!aNULL",      -- Ciphers that does not authenticate the connection
 133         };
 134 }
 135
 136 if luasec_has.curves then
 137         for i = #core_defaults.curveslist, 1, -1 do
 138                 if not luasec_has.curves[ core_defaults.curveslist[i] ] then
 139                         t_remove(core_defaults.curveslist, i);
 140                 end
 141         end
 142 else
 143         core_defaults.curveslist = nil;
 144 end
 145
 146 local path_options = { -- These we pass through resolve_path()
 147         key = true, certificate = true, cafile = true, capath = true, dhparam = true
 148 }
 149
 150 local function create_context(host, mode, ...)
 151         local cfg = new_config();
 152         cfg:apply(core_defaults);
 153         local service_name, port = host:match("^(%S+) port (%d+)$");
 154         if service_name then
 155                 cfg:apply(find_service_cert(service_name, tonumber(port)));
 156         else
 157                 cfg:apply(find_host_cert(host));
 158         end
 159         cfg:apply({
 160                 mode = mode,
 161                 -- We can't read the password interactively when daemonized
 162                 password = function() log("error", "Encrypted certificate for %s requires 'ssl' 'password' to be set in config", host); end;
 163         });
 164         cfg:apply(global_ssl_config);
 165
 166         for i = select('#', ...), 1, -1 do
 167                 cfg:apply(select(i, ...));
 168         end
 169         local user_ssl_config = cfg:final();
 170
 171         if mode == "server" then
 172                 if not user_ssl_config.certificate then
 173                         log("info", "No certificate present in SSL/TLS configuration for %s. SNI will be required.", host);
 174                 end
 175                 if user_ssl_config.certificate and not user_ssl_config.key then return nil, "No key present in SSL/TLS configuration for "..host; end
 176         end
 177
 178         for option in pairs(path_options) do
 179                 if type(user_ssl_config[option]) == "string" then
 180                         user_ssl_config[option] = resolve_path(config_path, user_ssl_config[option]);
 181                 else
 182                         user_ssl_config[option] = nil;
 183                 end
 184         end
 185
 186         -- LuaSec expects dhparam to be a callback that takes two arguments.
 187         -- We ignore those because it is mostly used for having a separate
 188         -- set of params for EXPORT ciphers, which we don't have by default.
 189         if type(user_ssl_config.dhparam) == "string" then
 190                 local f, err = io_open(user_ssl_config.dhparam);
 191                 if not f then return nil, "Could not open DH parameters: "..err end
 192                 local dhparam = f:read("*a");
 193                 f:close();
 194                 user_ssl_config.dhparam = function() return dhparam; end
 195         end
 196
 197         local ctx, err = ssl_newcontext(user_ssl_config);
 198
 199         -- COMPAT Older LuaSec ignores the cipher list from the config, so we have to take care
 200         -- of it ourselves (W/A for #x)
 201         if ctx and user_ssl_config.ciphers then
 202                 local success;
 203                 success, err = ssl_context.setcipher(ctx, user_ssl_config.ciphers);
 204                 if not success then ctx = nil; end
 205         end
 206
 207         if not ctx then
 208                 err = err or "invalid ssl config"
 209                 local file = err:match("^error loading (.-) %(");
 210                 if file then
 211                         local typ;
 212                         if file == "private key" then
 213                                 typ = file;
 214                                 file = user_ssl_config.key or "your private key";
 215                         elseif file == "certificate" then
 216                                 typ = file;
 217                                 file = user_ssl_config.certificate or "your certificate file";
 218                         end
 219                         local reason = err:match("%((.+)%)$") or "some reason";
 220                         if reason == "Permission denied" then
 221                                 reason = "Check that the permissions allow Prosody to read this file.";
 222                         elseif reason == "No such file or directory" then
 223                                 reason = "Check that the path is correct, and the file exists.";
 224                         elseif reason == "system lib" then
 225                                 reason = "Previous error (see logs), or other system error.";
 226                         elseif reason == "no start line" then
 227                                 reason = "Check that the file contains a "..(typ or file);
 228                         elseif reason == "(null)" or not reason then
 229                                 reason = "Check that the file exists and the permissions are correct";
 230                         else
 231                                 reason = "Reason: "..tostring(reason):lower();
 232                         end
 233                         log("error", "SSL/TLS: Failed to load '%s': %s (for %s)", file, reason, host);
 234                 else
 235                         log("error", "SSL/TLS: Error initialising for %s: %s", host, err);
 236                 end
 237         end
 238         return ctx, err, user_ssl_config;
 239 end
 240
 241 local function reload_ssl_config()
 242         global_ssl_config = configmanager.get("*", "ssl");
 243         global_certificates = configmanager.get("*", "certificates") or "certs";
 244         if luasec_has.options.no_compression then
 245                 core_defaults.options.no_compression = configmanager.get("*", "ssl_compression") ~= true;
 246         end
 247 end
 248
 249 prosody.events.add_handler("config-reloaded", reload_ssl_config);
 250
 251 return {
 252         create_context = create_context;
 253         reload_ssl_config = reload_ssl_config;
 254         find_cert = find_cert;
 255 };