Settings (unset options stripped):

[network] (weechat.conf)
  weechat.network.gnutls_ca_file = "/etc/ssl/certs/ca-certificates.crt"

[server] (irc.conf)
  irc.server.freenode.addresses = "chat.freenode.net/7000"
  irc.server.freenode.ssl = on
  irc.server.freenode.ssl_dhkey_size = 1024
  irc.server.freenode.ssl_verify = on


Connecting to Freenode:

irc: connecting to server chat.freenode.net/7000 (SSL)...
gnutls: connected using 1024-bit Diffie-Hellman shared secret exchange

gnutls: peer's certificate is trusted
gnutls: receiving 2 certificates
 - certificate[1] info:
   - subject `OU=Domain Control Validated,OU=Gandi Standard Wildcard SSL,CN=*.freenode.net', issuer `C=FR,O=GANDI SAS,CN=Gandi Standard SSL CA', RSA key 2048
bits, signed using RSA-SHA1, activated `2011-01-14 00:00:00 UTC', expires `2012-01-14 23:59:59 UTC', SHA-1 fingerprint
`acd50e69ad93f5db08fefb67180d871415858664'
 - certificate[2] info:
   - subject `C=FR,O=GANDI SAS,CN=Gandi Standard SSL CA', issuer `C=US,ST=UT,L=Salt Lake City,O=The USERTRUST
Network,OU=http://www.usertrust.com,CN=UTN-USERFirst-Hardware', RSA key 2048 bits, signed using RSA-SHA1, activated `2008-10-23 00:00:00 UTC', expires
`2020-05-30 10:48:38 UTC', SHA-1 fingerprint `a9f79883a075ce82d20d274d1368e876140d33b3'
irc: connected to chat.freenode.net/7000 (86.65.39.15)
pratchett.freenode.net (pratchett.freenode.net): *** Looking up your hostname...
pratchett.freenode.net (pratchett.freenode.net): *** Checking Ident
pratchett.freenode.net (pratchett.freenode.net): *** Found your hostname
pratchett.freenode.net (pratchett.freenode.net): *** No Ident response
irc: nickname "jakob" is already in use, trying nickname #2 ("jakob1")
Welcome to the freenode Internet Relay Chat Network jakob1