Re: Length of pre-shared key

[Dan Harkins <dharkins@tibernian.com>]

  IKE uses the pre-shared key as the key to an HMAC. RFC2104 specifies
that the key to an HMAC should not be less than the output of the under-
lying hash function. So if you're using HMAC-SHA that's 20 bytes.

  Dan.

On Mon, 25 Feb 2002 16:41:20 +0200 you wrote
> 	Hello!
> 
> Have IPsec and IKE specifications any requirements about the pre-shared keys?
> I didn't find the required length of pre-shared key.
> 
> Best Regards,
> Juha Ollila