root@raspi:~#
root@raspi:~# apt-get install ca-certificates ntpdate git-core rpi-update
Reading package lists... Done
Building dependency tree
Reading state information... Done
ca-certificates is already the newest version.
git-core is already the newest version.
git-core set to manually installed.
ntpdate is already the newest version.
rpi-update is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
root@raspi:~# rpi-update
 *** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS
 *** Performing self-update
--2014-03-27 13:48:29--  https://github.com/Hexxeh/rpi-update/raw/master/rpi-update
Resolving github.com (github.com)... 192.30.252.128
Connecting to github.com (github.com)|192.30.252.128|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://raw.githubusercontent.com/Hexxeh/rpi-update/master/rpi-update [following]
--2014-03-27 13:48:35--  https://raw.githubusercontent.com/Hexxeh/rpi-update/master/rpi-update
Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 185.31.17.133
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|185.31.17.133|:443... connected.
GnuTLS: A TLS warning alert has been received.
Unable to establish SSL connection.
 !!! Failed to download update for rpi-update!
 !!! Make sure you have ca-certificates installed and that the time is set correctly
root@raspi:~#