Re: [dpdk-users] AES GCM PMD Driver IV length support

[Nubin Stanley <nubinstanley@gmail.com>]

Hi Fiona

Thank you for the info.

And, I am adding the mailing list again. Sorry, I missed earlier.

Regards
Nubin Stanley

On Fri, Dec 9, 2016 at 3:41 PM, Trahe, Fiona <fiona.trahe@intel.com> wrote:

> I’m looking at version 16.11
>
> I think that code accepting 16 bytes padded and the 15th byte set may be
> removed in next release so only 12 bytes iv will be accepted.
>
> So keep an eye out for that patch as you’ll have to revert back.
>
> Btw- it’s better to keep these mails on the forum, with inline answers,
> cause others may have the same problem and benefit from this J
>
>
>
> *From:* Nubin Stanley [mailto:nubinstanley@gmail.com]
> *Sent:* Friday, December 9, 2016 8:22 AM
> *To:* Trahe, Fiona <fiona.trahe@intel.com>
> *Subject:* Re: [dpdk-users] AES GCM PMD Driver IV length support
>
>
>
> Hi  Fiona
>
> Thanks for the quick response.
>
> It seems the DPDK version I am using is different (16.07).
>
>
>
> The sanity code in the PMD code does not accept an IV len of 12.
>
>
>
>     if (op->cipher.iv.length != 16 && op->cipher.iv.length != 0) {
>
>         GCM_LOG_ERR("iv");
>
>         return -1;
>
>     }
>
>
>
> Anyways, I have circumvented the problem  by padding the IV  data in my
> application and it works.
>
>
>
> *   iv_pad_len = RTE_ALIGN_CEIL(entry->iv.length, 16);*
>
> *   op->sym->cipher.iv.data = rte_malloc("iv", iv_pad_len, 0);*
>
> *   memcpy(op->sym->cipher.iv.data, entry->iv.data, entry->iv.length);*
>
> *   op->sym->cipher.iv.phys_addr =
> rte_malloc_virt2phy(op->sym->cipher.iv.data);*
>
> *   op->sym->cipher.iv.length = iv_pad_len;*
>
> *   op->sym->cipher.iv.data[15] = 1;*
>
>
>
> Could you please let me know the version of DPDK you are using.
>
> Thanks again for the support.
>
>
>
> Regards
>
> Nubin Stanley
>
>
>
> On Thu, Dec 8, 2016 at 4:26 PM, Trahe, Fiona <fiona.trahe@intel.com>
> wrote:
>
> Hi Nubin,
>
>
> > -----Original Message-----
> > From: users [mailto:users-bounces@dpdk.org] On Behalf Of Nubin Stanley
> > Sent: Thursday, December 8, 2016 9:21 AM
> > To: users@dpdk.org
> > Cc: martin.varghese@nokia.com
> > Subject: [dpdk-users] AES GCM PMD Driver IV length support
> >
> > Hi All
> >
> >
> >
> > I see that the only IV size supported in AES GCM driver is 16bytes. For
> > using AES-GCM-128  in IPsec, the IV length  has to be   12 bytes ( 4
> (salt)
> > + 8 (iv)).
> >
> >
> > How should I handle this IPsec case with AES GCM PMD driver.
> >
> >
> >
> > .op = RTE_CRYPTO_OP_TYPE_SYMMETRIC,
> >
> >         {.sym = {
> >
> >             .xform_type = RTE_CRYPTO_SYM_XFORM_CIPHER,
> >
> >             {.cipher = {
> >
> >                 .algo = RTE_CRYPTO_CIPHER_AES_GCM,
> >
> >                 .block_size = 16,
> >
> >                 .key_size = {
> >
> >                     .min = 16,
> >
> >                     .max = 16,
> >
> >                     .increment = 0
> >
> >                 },
> >
> >                 .iv_size = {
> >
> >                     .min = 16,
> >
> >                     .max = 16,
> >
> >                     .increment = 0
> >
> >                 }
> >
> >             }, }
> >
> >         }, }
> >
> >
> >
> > Regards,
> > Nubin Stanley
>
> I found the following code in the PMD to handle an iv length of 12, so
> this looks like a bug in the capability data.
> /* sanity checks */
>         if (op->cipher.iv.length != 16 && op->cipher.iv.length != 12 &&
>                         op->cipher.iv.length != 0) {
>                 GCM_LOG_ERR("iv");
>                 return -1;
>         }
>
>         /*
>          * GCM working in 12B IV mode => 16B pre-counter block we need
>          * to set BE LSB to 1, driver expects that 16B is allocated
>          */
>         if (op->cipher.iv.length == 12) {
>                 op->cipher.iv.data[15] = 1;
>         }
>
> Have you tried passing a 12-byte iv to the driver ?
>
>
>
>
>
> --
>
> Nubin Stanley
> Electronics and Biomedical Engineering
> Batch of 2009
> Model Engineering College, Kochi
> Phone : +918147742665 <081477%2042665>
> Email  : nubinstanley@gmail.com
>



-- 
Nubin Stanley
Electronics and Biomedical Engineering
Batch of 2009
Model Engineering College, Kochi
Phone : +918147742665
Email  : nubinstanley@gmail.com