On Thu, Jan 4, 2018 at 2:57 AM, Dmitry Eremin-Solenikov <[email protected]> wrote: > 2018-01-03 12:44 GMT+03:00 Nikos Mavrogiannopoulos > <[email protected]>: >> On Sat, Oct 7, 2017 at 8:55 PM, Dmitry Eremin-Solenikov >> <[email protected]> wrote: >>> Add CFB mode support. CFB uses segment size = block size. >>> >>> Changes since V2: >>> >>> - Dropped CFB8, isn't widely used. >> >> I'm getting late into this discussion, but it seems that samba (which >> uses nettle and gnutls), could benefit from an 8-bit CFB mode as well. >> They are already implementing it on top of nettle, and it is being >> used on the newer samba versions: >> >> https://git.samba.org/?p=samba.git;a=blob;f=lib/crypto/REQUIREMENTS;h=351c2bb99b4d760aeaf47ef47b3a489187f60488;hb=refs/heads/master > > Hmm, interesting. It looks like they miss CFB8 and CMAC. However > from the first glance I could not understand, do they reference nettle/ > GNUTLS as code reference, or are they using them as crypto backends? > Skimming over WAF scripts did not give me the answer.
They are used as backends, though they also re-implement quite few stuff. My understanding is that they would like to get rid of their crypto implementations, and rely on nettle and gnutls for that. > I can (re-)post CFB8 if that will be helpful to Samba (or other parties). > CMAC also sounds like and interesting topic. Niels what do think about CFB8? On that view, I've compiled a list of new modes which seem to be useful in other applications: AES-CMAC: fast MAC used in samba and there is a draft for NTP protocol. There is implementation in samba at [1]. AES-XTS: it is a mode used in disk volume encryption when no authentication is to be present (ntfs and luks can use it). It is implemented in qemu [0] which already has a nettle back-end. AES-SIV-CMAC: An AES AEAD mode which does not fail secrecy/catastrophically when a nonce is repeated. There is a draft for its use under NTP (draft-ietf-ntp-using-nts-for-ntp-10). regards, Nikos [0]. https://github.com/qemu/qemu/blob/507e4ddc3abf67391bcbc9624fd60b969c159b78/crypto/xts.c [1]. https://github.com/samba-team/samba/blob/d8a5565ae647352d11d622bd4e73ff4568678a7c/lib/crypto/aes_cmac_128.c _______________________________________________ nettle-bugs mailing list [email protected] http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs
