List failed login attempts on Yosemite
sshd logging is determined in /etc/asl/com.openssh.sshd.

In short, you need to touch a file and then send syslogd a HUP signal:
touch /var/run/com.openssh.sshd-asl-enabled
kill -HUP $(ps -ef | grep [s]yslogd | awk '{print $2}')

After that, you will find the logs in /var/log/sshd.log