Fast one step Putty login by specifying private key location and passphrase on command line or Windoze shortcut.
For those lazy folk like me wanting a single click logon to a FreeNAS machine using SSH keypairs and optional passphrase the following command line format (or target text for a windows shortcut) works a treat.
"C:\Program Files (x86)\PuTTY\putty.exe" -ssh
accountname@I.P.Addre.ss sshport -i c:\SSH_Keys\freenas-privatekey.ppk -pw yourpassphrase
Where
"C:\Program Files (x86)\PuTTY\putty.exe" is the filespec for the location of the putty executable
-ssh is the putty switch denoting a SSH connection
accountname@I.P.Adre.ss is the user name and server address - ie root@1.2.3.4 or freenasadmin@9.8.7.6 or whatever
sshport is the port used to pass the SSH protocol on the server or access router (leave blank for the default ssh port (22)
-i is the Putty switch to specify the private key location and name for key pair authentication
-pw is the Putty switch to define a password or passphrase or other text string to pass to the server after ssh connection
yourpassphrase is the passphrase defined during the private key generation which is passed after initial ssh connection
Note 1 - All of the above fields must be separated by a space
Note 2 - quotations are necessary in most cases where spaces or control characters are used"
Note 3 - -pw yourpassphrase can be omitted if a passphrase is not being used (however a passphrase is recommended just in case someone gets hold of your private key.
Personally I found the above tutorial by the writer (carmorales) extremely helpful, very concise and it worked right out of the box.
I hope this contribution is also helpful to those using Putty / Key pair authentication login.