topic Re: cisco 5525 ver 9.8(2) how to enter a 4096bit ssh public key? in Network Security

cisco 5525 ver 9.8(2) how to enter a 4096bit ssh public key?

cealt45661 — Wed, 03 Mar 2021 20:30:37 GMT

asa 5525 Version 9.8(2)

We all have 4096 bit public keys. These apparently are too big for the character buffer (ERROR: Input line size exceeded available buffer (510 characters).

in other cisco gear I've used "fold -b -w 72 ..."on the *nix box, and then was able to use key-string to paste the multistring output of the fold. Apparently there is no equivalent to key-string in the ASA?

If not, then how do I put in our public keys?

thanks in advance

Re: cisco 5525 ver 9.8(2) how to enter a 4096bit ssh public key?

Rob Ingram — Wed, 03 Mar 2021 20:34:17 GMT

Hi @cealt45661

It doesn't appear that the ASA 5525 supports 4096bit keys

"The 4096-bit RSA keys are only supported on the ASA5580, 5585, or later platforms."

Reference:- https://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-next-generation-firewalls/200150-Cisco-Guide-to-Harden-Cisco-ASA-Firewall.html#anc16

Re: cisco 5525 ver 9.8(2) how to enter a 4096bit ssh public key?

cealt45661 — Wed, 03 Mar 2021 20:40:33 GMT

Hm. That is truly a shame.

Thank you.