content/kb/connect/chat.md

   1 Title: Connecting to freenode
   2 Slug: chat
   3 ---
   4
   5 The freenode network can be accessed via the [freenode
   6 webchat](//webchat.freenode.net) or using an IRC client such as irssi, WeeChat,
   7 ERC, HexChat, Smuxi, Quassel or mIRC.
   8
   9 You can connect to freenode by pointing your IRC client at `chat.freenode.net`
  10 on ports 6665-6667 and 8000-8002 for plain-text connections, or ports 6697, 7000
  11 and 7070 for TLS-encrypted connections.
  12
  13 ## Accessing freenode Via TLS
  14
  15 freenode provides TLS client access on all servers, on ports 6697, 7000 and
  16 7070. Users connecting over TLS will be given user mode +Z, and _is using a
  17 secure connection_ will appear in WHOIS (a 671 numeric).
  18
  19 In order to verify the server certificates on connection, some additional work
  20 may be required. First, ensure that your system has an up-to-date set of root
  21 CA certificates. On most linux distributions this will be in a package named
  22 something like ca-certificates. Many systems install these by default, but some
  23 (such as FreeBSD) do not.  For FreeBSD, the package is named ca\_root\_nss,
  24 which will install the appropriate root certificates in
  25 /usr/local/share/certs/ca-root-nss.crt.
  26
  27 Certificate verification will generally only work when connecting to
  28 **`freenode.net`**. If your client thinks the server's certificate is invalid,
  29 make sure you are connecting to `chat.freenode.net` rather than any other name
  30 that leads to freenode.
  31
  32 For most clients this should be sufficient. If not, you can download the root
  33 certificate from
  34 [LetsEncrypt](https://letsencrypt.org/certificates/).
  35
  36 Client TLS certificates are also supported, and may be used for identification
  37 to services. See [this kb article](kb/using/certfp). If you have connected with
  38 a client certificate, _has client certificate fingerprint
  39 f1ecf46714198533cda14cccc76e5d7114be4195_ (showing your certificate's SHA1
  40 fingerprint in place of _f1ecf46..._) will appear in WHOIS (a 276 numeric).
  41
  42 ## Accessing freenode Via Tor
  43
  44 freenode is also reachable via [Tor<i class="fa fa-external-link"
  45 aria-hidden="true"></i>](https://www.torproject.org/), bound to some
  46 restrictions. You can't directly connect to chat.freenode.net via Tor; use
  47 the following hidden service as the server address instead:
  48
  49     ajnvpgl6prmkb7yktvue6im5wiedlz2w32uhcwaamdiecdrfpwwgnlqd.onion
  50
  51 The hidden service requires SASL authentication. In addition, due to the abuse
  52 that led Tor access to be disabled in the past, we have unfortunately had to
  53 add another couple of restrictions:
  54
  55 - You must log in using SASL `EXTERNAL` or `ECDSA-NIST256P-CHALLENGE` (more
  56   below)
  57 - If you log out while connected via Tor, you will not be able to log in
  58   without reconnecting.
  59
  60 If you haven't set up the requisite SASL authentication, we recommend SASL
  61 EXTERNAL. You'll need to generate a client certificate and add that to your
  62 NickServ account. This is documented [in our knowledge base](kb/using/certfp).
  63
  64 Connecting using SASL EXTERNAL requires that you connect using TLS encryption.
  65
  66 You'll then want to tell your client to try the `EXTERNAL` mechanism. We lack
  67 comprehensive documentation for this, but it's a feature in most modern
  68 clients, so please check their docs for instructions for now.
  69
  70 ### Verifying Tor TLS connections
  71
  72 A Tor hidden service name securely identifies the service you are connecting to. Verifying the TLS server certificate is strickly-speaking unnecessary while using the hidden service. Nonetheless the following methods can be used to verify the hidden service's TLS server certificate.
  73
  74 The best way to ensure the TLS server-side certificate successfully validates is to add the following fragment to your `torrc` configuration file and configure your client to connect to `zettel.freenode.net` via Tor. The TLS server certificate used by the hidden service will validate using this hostname.
  75
  76     # torrc snippet:
  77     MapAddress zettel.freenode.net ajnvpgl6prmkb7yktvue6im5wiedlz2w32uhcwaamdiecdrfpwwgnlqd.onion
  78
  79 Older clients that don't support SOCKS4a or later will need to use `MapAddress` with an IP address, and the certificate will not validate successfully. In this case validation will need to be disabled.
  80
  81 Note that the hidden service's certificate changes periodically as it is updated. This means that the *certificate fingerprint* can not be reliably pinned. A few clients support *public key pinning*, however. For these clients the following *public key fingerprint* can be pinned:
  82
  83     # sha256 public key fingerprint
  84     E0:1B:31:80:56:D9:78:C4:2B:2D:3F:B2:DB:81:AB:03:15:59:BF:04:7E:31:E8:60:5F:98:07:A1:BB:8F:A3:0D