1. Issue
Since November 2016, SSH server on Raspbian is disabled by default. On the first boot, you’ll find a closed door :
Permission denied, please try again.
2. Option 1 : Direct access
If you have a keyboard and a screen, you might used the well known :
sudo raspi-config
And then go to : Interfacing options > ssh > Enable or disable ssh server
1. Option 2 : Headless
Like me, you always set-up headless server with your pi, then you need to write a file on the Pi SD card (on the /boot).
touch /media/MyPiBootMountPoint/ssh
The SSH server will be activated on the first boot !