Martin, Thank you for your prompt answer. Now I understand what they really mean.
Regards, On 2013/01/22, at 19:39, Martin Willi <[email protected]> wrote: > Hi, > >> ike=aes256gcm16-aesxcbc-modp2048! >> esp=aes256gcm16-modp2048! > >> [...] why we need "aesxcbc" for "ike" in conjunction with >> "aes256gcm16"? > > In the "esp" keyword, you define an encryption and an integrity > algorithm, and optionally a DH group used when rekeying the CHILD_SA. > > In the "ike" keyword, you additionally need a Pseudo Random Function > (PRF) to derive keys. This usually is the same as the integrity > algorithm, hence you don't need to specify it explicitly. With an AEAD > algorithm (such as GCM), there is no dedicated integrity algorithm, so a > dedicated PRF is required. > > In this example, aesxcbc is used as PRF only, as you don't have a > dedicated cipher, but only an AEAD. > > Starting from the upcoming 5.0.2 release, you can explicitly define the > PRF using the "prf" algorithm prefix (such as prfaesxcbc). The old > syntax using implicitly defined PRFs is still supported, though. > > Regards > Martin > --- Motonori Shindo _______________________________________________ Users mailing list [email protected] https://lists.strongswan.org/mailman/listinfo/users
