To generate the key pair from ASDM go to Configuration, then select the Device Management tab.
Expand Certificate Management and go to Identity Certificates.
Click Add and select the Add a New Identity Certificate radio button. Then click New.
In the Add Key Pair dialog box, take the defaults and click Generate Now.
Don’t forget to go to Device Management > Management Access > ASDM/HTTPS/Telnet/SSH and allow SSH access on the appropriate interface and source IP addresses.
