Add certificate inspection header

[irc/freenode/web-7.0.git] / content / kb / connect / chat.md

diff --git a/content/kb/connect/chat.md b/content/kb/connect/chat.md
index d70a78d2cc4e9758efbfbc8c6d99e389b567012f..ee7e4e7cbdb82146126dcb2c9b7772bbddb27416 100644 (file)
--- a/content/kb/connect/chat.md
+++ b/content/kb/connect/chat.md
@@ -7,15 +7,14 @@ webchat](//webchat.freenode.net) or using an IRC client such as irssi, WeeChat,
 ERC, HexChat, Smuxi, Quassel or mIRC.
 
 You can connect to freenode by pointing your IRC client at `chat.freenode.net`
-on ports 6665-6667 and 8000-8002.
+on ports 6665-6667 and 8000-8002 for plain-text connections, or ports 6697, 7000
+and 7070 for TLS-encrypted connections.
 
-## Accessing freenode Via SSL
+## Accessing freenode Via TLS
 
-freenode provides SSL client access on all servers, on ports 6697, 7000 and
-7070. Users connecting over SSL will be given user mode +Z, and _is using a
-secure connection_ will appear in WHOIS (a 671 numeric). Webchat users will not
-currently appear with +Z or the 671 numeric, even if they connect to webchat
-via SSL.
+freenode provides TLS client access on all servers, on ports 6697, 7000 and
+7070. Users connecting over TLS will be given user mode +Z, and _is using a
+secure connection_ will appear in WHOIS (a 671 numeric).
 
 In order to verify the server certificates on connection, some additional work
 may be required. First, ensure that your system has an up-to-date set of root
@@ -32,9 +31,9 @@ that leads to freenode.
 
 For most clients this should be sufficient. If not, you can download the root
 certificate from
-[IdenTrust](https://www.identrust.com/certificates/trustid/root-download-x3.html).
+[LetsEncrypt](https://letsencrypt.org/certificates/).
 
-Client SSL certificates are also supported, and may be used for identification
+Client TLS certificates are also supported, and may be used for identification
 to services. See [this kb article](kb/using/certfp). If you have connected with
 a client certificate, _has client certificate fingerprint
 f1ecf46714198533cda14cccc76e5d7114be4195_ (showing your certificate's SHA1
@@ -47,7 +46,7 @@ aria-hidden="true"></i>](https://www.torproject.org/), bound to some
 restrictions. You can't directly connect to chat.freenode.net via Tor; use
 the following hidden service as the server address instead:
 
-    freenodeok2gncmy.onion
+    ajnvpgl6prmkb7yktvue6im5wiedlz2w32uhcwaamdiecdrfpwwgnlqd.onion
 
 The hidden service requires SASL authentication. In addition, due to the abuse
 that led Tor access to be disabled in the past, we have unfortunately had to
@@ -62,12 +61,24 @@ If you haven't set up the requisite SASL authentication, we recommend SASL
 EXTERNAL. You'll need to generate a client certificate and add that to your
 NickServ account. This is documented [in our knowledge base](kb/using/certfp).
 
-Note that due to the SSL certificates not matching the hidden service, you
-might have to disable the verification in your client. If your client supports
-*key* pinning, you can verify our Tor server's public key fingerprint:
-
-    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
+Connecting using SASL EXTERNAL requires that you connect using TLS encryption.
 
 You'll then want to tell your client to try the `EXTERNAL` mechanism. We lack
 comprehensive documentation for this, but it's a feature in most modern
 clients, so please check their docs for instructions for now.
+
+### Verifying Tor TLS connections
+
+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.
+
+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.
+
+    # torrc snippet:
+    MapAddress zettel.freenode.net ajnvpgl6prmkb7yktvue6im5wiedlz2w32uhcwaamdiecdrfpwwgnlqd.onion
+
+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.
+
+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:
+
+    # sha256 public key fingerprint
+    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