Sicher fragt man sich warum wir kein ejabberd nutzen. Dies ist schlicht und ergreifend eigenen Präferenz. Ich persönlich störe mich daran bei ejabberd die Cipher-Suites für den verschlüsselten Austausch mit anderen Servern nicht manuell einstellen zu können. Weiterhin lässt sich ejabberd meiner Meinung schlechter warten, da es mit erlang geschrieben wurde. Prosody im Kontrast wurde mit lua geschrieben. Alleine schon die Packages die für den Betrieb benötigt werden sind kleiner und weniger von der Anzahl her. Weiterhin verbraucht Prosody nur 1/3 des Speicherbedarfs von ejabberd.
Vorausgesetzt wird ein Debian Jessie 8.1 System.
Als erstes muss die Paketquelle von Prosody hinzugefügt werden:
echo "deb http://packages.prosody.im/debian jessie main" > /etc/apt/sources.list.d/prosody.sources.list wget https://prosody.im/files/prosody-debian-packages.key -O- | apt-key add - apt-get update
Nachdem dies erledigt wurde wird prosody an sich installiert:
apt-get update apt-get install prosody lua-sec lua-dbi-mysql lua-event lua-zlib
Sollte die Version von lua-sec aus dem offiziellen Package Repos < 5.0 sein solltet ihr anstelle von lua-sec lua-sec-prosody installieren. Dies trifft zum Beispiel auf Debian Wheezy zu.
Da es nur Clients aus dem FFPI Netz erlaubt werden soll einen Account beim XMPP Server zu erstellen und dieser Account weiterhin auf beiden Hosts (xmpp.ffpi und xmpp.pinneberg.freifunk.net) registriert werden muss benutzen wir mod_register_web in einer modifizierten Version.
cd /usr/lib/prosody/modules/ apt-get install git git clone https://github.com/freifunk-pinneberg/mod_register_web.git
Als erstes wird der DH-Schlüssel für FS (Forward Secrecy) generiert:
openssl dhparam -out /etc/prosody/certs/dh_4096.pem 4096
Dies kann einige Zeit dauern. In der Zwischenzeit erstellen wir daher einen User und eine Datenbank für prosody:
mysql -u root -p mysql> create database prosody; mysql> grant usage on *.* to prosody@localhost identified by 'extremelySECRET'; mysql> grant all privileges on prosody.* to prosody@localhost;
Nun geht es an die eigentliche Konfiguration von Prosody. Die Namen der Domainzertifikate sowie die Domain müssen natürlich entsprechend ausgefüllt werden.
-- Prosody XMPP Server Configuration -- -- Information on configuring Prosody can be found on our -- website at http://prosody.im/doc/configure -- -- Tip: You can check that the syntax of this file is correct -- when you have finished by running: luac -p prosody.cfg.lua -- If there are any errors, it will let you know what and where -- they are, otherwise it will keep quiet. -- -- Good luck, and happy Jabbering! ---------- Server-wide settings ---------- -- Settings in this section apply to the whole server and are the default settings -- for any virtual hosts -- This is a (by default, empty) list of accounts that are admins -- for the server. Note that you must create the accounts separately -- (see http://prosody.im/doc/creating_accounts for info) -- Example: admins = { "user1@example.com", "user2@example.net" } admins = {} -- Enable use of libevent for better performance under high load -- For more information see: http://prosody.im/doc/libevent use_libevent = true; plugin_paths = {"" } -- This is the list of modules Prosody will load on startup. -- It looks for mod_modulename.lua in the plugins folder, so make sure that exists too. -- Documentation on modules can be found at: http://prosody.im/doc/modules modules_enabled = { -- Generally required "roster"; -- Allow users to have a roster. Recommended ;) "saslauth"; -- Authentication for clients and servers. Recommended if you want to log in. "tls"; -- Add support for secure TLS on c2s/s2s connections "dialback"; -- s2s dialback support "disco"; -- Service discovery "posix"; -- POSIX functionality, sends server to background, enables syslog, etc. -- Not essential, but recommended "private"; -- Private XML storage (for room bookmarks, etc.) "vcard"; -- Allow users to set vCards -- These are commented by default as they have a performance impact --"privacy"; -- Support privacy lists "compression"; -- Stream compression (requires the lua-zlib package installed) -- Nice to have "http"; "register_web"; "version"; -- Replies to server version requests "uptime"; -- Report how long server has been running "time"; -- Let others know the time here on this server "ping"; -- Replies to XMPP pings with pongs "pep"; -- Enables users to publish their mood, activity, playing music and more --"register"; -- Allow users to register on this server using a client and change passwords -- Admin interfaces "admin_adhoc"; -- Allows administration via an XMPP client that supports ad-hoc commands --"admin_telnet"; -- Opens telnet console interface on localhost port 5582 -- HTTP modules --"bosh"; -- Enable BOSH clients, aka "Jabber over HTTP" "http_files"; -- Serve static files from a directory over HTTP -- Other specific functionality --"groups"; -- Shared roster support --"announce"; -- Send announcement to all online users --"welcome"; -- Welcome users who register accounts --"watchregistrations"; -- Alert admins of registrations --"motd"; -- Send a message to users when they log in --"legacyauth"; -- Legacy authentication. Only used by some old clients and bots. }; -- These modules are auto-loaded, but should you want -- to disable them then uncomment them here: modules_disabled = { -- "offline"; -- Store offline messages -- "c2s"; -- Handle client connections -- "s2s"; -- Handle server-to-server connections }; -- Disable account creation by default, for security -- For more information see http://prosody.im/doc/creating_accounts allow_registration = true; registration_hosts={'xmpp.ffpi', 'xmpp.pinneberg.freifunk.net'} daemonize = true; -- Required for init scripts and prosodyctl pidfile = "/var/run/prosody/prosody.pid"; http_files_dir="/usr/lib/prosody/modules/mod_register_web/templates/ressources/"; http_dir_listing=true; http_ports = { 5280 } http_interfaces = { "127.0.0.1","::1" } -- These are the SSL/TLS-related settings. If you don't want -- to use SSL/TLS, you may comment or remove this ssl = { key = "/etc/prosody/certs/localhost.key"; certificate = "/etc/prosody/certs/localhost.crt"; } -- Force clients to use encrypted connections? This option will -- prevent clients from authenticating unless they are using encryption. c2s_require_encryption = true -- Force certificate authentication for server-to-server connections? -- This provides ideal security, but requires servers you communicate -- with to support encryption AND present valid, trusted certificates. -- NOTE: Your version of LuaSec must support certificate verification! -- For more information see http://prosody.im/doc/s2s#security s2s_require_encryption = true s2s_secure_auth = false -- Many servers don't support encryption or have invalid or self-signed -- certificates. You can list domains here that will not be required to -- authenticate using certificates. They will be authenticated using DNS. s2s_insecure_domains = { "gmail.com" } -- Even if you leave s2s_secure_auth disabled, you can still require valid -- certificates for some domains by specifying a list here. s2s_secure_domains = { "jabber.org" } -- Select the authentication backend to use. The 'internal' providers -- use Prosody's configured data storage to store the authentication data. -- To allow Prosody to offer secure authentication mechanisms to clients, the -- default provider stores passwords in plaintext. If you do not trust your -- server please see http://prosody.im/doc/modules/mod_auth_internal_hashed -- for information about using the hashed backend. --authentication = "internal_plain" -- we want passwords to be hashed on disk! authentication = "internal_hashed" -- Select the storage backend to use. By default Prosody uses flat files -- in its configured data directory, but it also supports more backends -- through modules. An "sql" backend is included by default, but requires -- additional dependencies. See http://prosody.im/doc/storage for more info. storage = "sql" -- Default is "internal" -- For the "sql" backend, you can uncomment *one* of the below to configure: --sql = { driver = "SQLite3", database = "prosody.sqlite" } -- Default. 'database' is the filename. sql = { driver = "MySQL", database = "prosody", username = "prosody", password = "extremelySECRET", host = "localhost" } --sql = { driver = "PostgreSQL", database = "prosody", username = "prosody", password = "secret", host = "localhost" } -- Logging configuration -- For advanced logging see http://prosody.im/doc/logging log = { info = "/var/log/prosody/prosody.log"; -- Change 'info' to 'debug' for verbose logging error = "/var/log/prosody/prosody.err"; -- Syslog: { levels = { "error" }; to = "syslog"; }; -- "*syslog"; } http_paths = { register_web = "/"; files="/files"; } http_host = "127.0.0.1" ----------- Virtual hosts ----------- -- You need to add a VirtualHost entry for each domain you wish Prosody to serve. -- Settings under each VirtualHost entry apply *only* to that host. --VirtualHost "localhost" -- Section for host VirtualHost "xmpp.ffpi" --enabled = false -- Remove this line to enable this host -- Assign this host a certificate for TLS, otherwise it would use the one -- set in the global section (if any). -- Note that old-style SSL on port 5223 only supports one certificate, and will always -- use the global one. ssl = { key = "/etc/prosody/certs/localhost.key"; certificate = "/etc/prosody/certs/localhost.crt"; -- We do not want SSL2 and SSL3, no compression, no client cipher preference. options = { "no_sslv2", "no_sslv3", "no_ticket", "no_compression", "cipher_server_preference", "single_dh_use", "single_ecdh_use" }; --options = { "no_sslv2", "no_sslv3", "no_ticket", "no_compression", "single_dh_use", "single_ecdh_use" }; --options = { "no_sslv2", "no_sslv3", "no_compression", "cipher_server_preference" }; -- Only FS (Forward Secrecy) Ciphers ciphers = "EECDH+AESGCM:EDH+AESGCM:EECDH:EDH:AES256-GCM-SHA384:AES128-GCM-SHA256:!MD5:!RC4:!LOW:!MEDIUM:!CAMELLIA:!ECDSA:!DES:!DSS:!3DES:!NULL"; dhparam = "/etc/prosody/certs/dh_4096.pem"; } VirtualHost "xmpp.pinneberg.freifunk.net" --enabled = false -- Remove this line to enable this host -- Assign this host a certificate for TLS, otherwise it would use the one -- set in the global section (if any). -- Note that old-style SSL on port 5223 only supports one certificate, and will always -- use the global one. ssl = { key = "/etc/prosody/certs/localhost.key"; certificate = "/etc/prosody/certs/localhost.crt"; -- We do not want SSL2 and SSL3, no compression, no client cipher preference. options = { "no_sslv2", "no_sslv3", "no_ticket", "no_compression", "cipher_server_preference", "single_dh_use", "single_ecdh_use" }; --options = { "no_sslv2", "no_sslv3", "no_ticket", "no_compression", "single_dh_use", "single_ecdh_use" }; --options = { "no_sslv2", "no_sslv3", "no_compression", "cipher_server_preference" }; -- Only FS (Forward Secrecy) Ciphers ciphers = "EECDH+AESGCM:EDH+AESGCM:EECDH:EDH:AES256-GCM-SHA384:AES128-GCM-SHA256:!MD5:!RC4:!LOW:!MEDIUM:!CAMELLIA:!ECDSA:!DES:!DSS:!3DES:!NULL"; dhparam = "/etc/prosody/certs/dh_4096.pem"; } ------ Components ------ -- You can specify components to add hosts that provide special services, -- like multi-user conferences, and transports. -- For more information on components, see http://prosody.im/doc/components -- Set up a MUC (multi-user chat) room server on conference.example.com: --Component "conference.example.com" "muc" -- Set up a SOCKS5 bytestream proxy for server-proxied file transfers: --Component "proxy.example.com" "proxy65" ---Set up an external component (default component port is 5347) --Component "gateway.example.com" -- component_secret = "password"
Bei der Auswahl der Ciphers wurde ein besonderes Augenmerk auf die Sicherheit der Übertragung gelegt. Leider lässt sich eine eine ausschließe Verwendung von FS-Ciphers nicht umsetzen, da viele Server kein FS Support haben. Um aber trotzdem mit diesen Servern kommunizieren zu können wurde AES-128/256 im GCM (Galois-Counter-Mode) aktiviert.
Jetzt müssen noch die richtigen DNS Einträge für den Server gesetzt werden.
; _service._proto.name TTL class SRV priority weight port target
_xmpp-client._tcp.ffpi. 86400 IN SRV 5 0 5222 srv02.ffpi.
_xmpp-server._tcp.ffpi. 86400 IN SRV 5 0 5269 srv02.ffpi.
Abschließend Prosody einmal neustarten
service prosody restart