YubiKey NEO
Only the NEO has the smart card functionality right now.

install YubiKey NEO Manager
run the YubiKey NEO Manager
change connection mode
set OTP + CCID
unplug yubikey and plug it back in

install gpgtools (gnupg was not able to create the keys)
default admin-pin (PUK) = 12345678
default pin = 123456
gpg –card-edit

> admin
> generate
  enter admin-pin and pin
  never expires
  enter name, email and comment
  enter passphrase

gpg –card-status | grep “Signature key”
gpg –armor –export XXXXXXXX (8 last digits from signature key)

gpg-agent –enable-ssh-support –daemon ssh-add -l
2048 xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx cardno:000000000001 (RSA)
gpg-agent –enable-ssh-support –daemon ssh-add -L

 ssh-add AAAA[...your.key...] cardno:000000000001 \\

gpgkey2ssh XXXXXX > ~/.ssh/smartcard.pub
vi ~/.ssh/smartcard.pub
change COMMENT at the end of line to a description

vi ~/.gnupg/gpg-agent.conf

pinentry-program /usr/local/MacGPG2/libexec/pinentry-mac.app/Contents/MacOS/pinentry-mac
enable-ssh-support
write-env-file
use-standard-socket
default-cache-ttl 600
max-cache-ttl 7200

pkill gpg-agent

get socket:
gpg-connect-agent “getinfo ssh_socket_name” /bye
set socket:
export SSH_AUTH_SOCK=~/.gnupg/S.gpg-agent.ssh

your ssh public key is already prepared and stored in ~/.ssh/smartcard.pub
to use it you can add it to ~/.ssh/authorized_keys on the remote host
to use ssh-copy-id you need to create an empty “private key”
touch ~/.ssh/smartcard
ssh-copy-id -i ~/.ssh/smartcard.pub remotehostname

ssh servername
it should ask you for the pin and establish an ssh connection without asking for a password

gpg –change-pin