Hi Vinicius, > -----Original Message----- > From: linux-bluetooth-owner@xxxxxxxxxxxxxxx [mailto:linux-bluetooth- > owner@xxxxxxxxxxxxxxx] On Behalf Of Vinicius Costa Gomes > Sent: 07 December, 2010 11:23 AM > To: Brian Gix > Cc: linux-bluetooth@xxxxxxxxxxxxxxx > Subject: Re: [RFC v2 5/9] Bluetooth: Add support for using the crypto > subsystem > > Hi Brian, > > On 10:35 Tue 07 Dec, Brian Gix wrote: > > > > Hi Vinicius, > > > > > -----Original Message----- > > > From: linux-bluetooth-owner@xxxxxxxxxxxxxxx [mailto:linux- > bluetooth- > > > owner@xxxxxxxxxxxxxxx] On Behalf Of Vinicius Costa Gomes > > > Sent: 06 December, 2010 1:44 PM > > > To: linux-bluetooth@xxxxxxxxxxxxxxx > > > Cc: Vinicius Costa Gomes > > > Subject: [RFC v2 5/9] Bluetooth: Add support for using the crypto > > > subsystem > > > > > > This will allow using the crypto subsystem for encrypting data. As > SMP > > > (Security Manager Protocol) is implemented almost entirely on the > host > > > side and the crypto module already implements the needed methods > > > (AES-128), it makes sense to use it. > > > > I do understand the desire to reuse the crypto module, but I would > like > > to point out that every baseband that supports any level of LE-SM, is > > required to have implemented the HCI commands for LE-SM centric > encryption > > and random number generation. > > Yes, we are aware of that. > > > > > Also, since these are processor intensive calculations, which must > take > > place in real-time on the baseband for encrypted links, I would argue > > that it makes more sense to use the likely optimized functionality > > present in the basebands. > > I am sure that the baseband is optimized for those operations, but one > thing that needs to be considered is the time that the information > takes to get > to and from the baseband. For example, in the case of a USB controller, > we need > to build an HCI command, insert the command in the queue, and wait for > it to be > delivered (and received) via the USB bus to the baseband. Using the > crypto > subsystem we may even be able to use functionality built inside the > processor. > > > > > That is not to say that it cannot be done on the host, just that it > > is likely less efficient, for no gain in portability or > functionality. > > There is a gain in simplicity ;-) Well that's fine. Again, I have no objection. > > > > > > > > Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxxxxxx> > > > --- > > > include/net/bluetooth/hci_core.h | 2 ++ > > > net/bluetooth/hci_core.c | 10 ++++++++++ > > > 2 files changed, 12 insertions(+), 0 deletions(-) > > > > > > diff --git a/include/net/bluetooth/hci_core.h > > > b/include/net/bluetooth/hci_core.h > > > index 0687e2f..d0a9f5d 100644 > > > --- a/include/net/bluetooth/hci_core.h > > > +++ b/include/net/bluetooth/hci_core.h > > > @@ -135,6 +135,8 @@ struct hci_dev { > > > __u32 req_status; > > > __u32 req_result; > > > > > > + struct crypto_blkcipher *tfm; > > > + > > > struct inquiry_cache inq_cache; > > > struct hci_conn_hash conn_hash; > > > struct list_head blacklist; > > > diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c > > > index 12c6735..b96c3dd 100644 > > > --- a/net/bluetooth/hci_core.c > > > +++ b/net/bluetooth/hci_core.c > > > @@ -41,6 +41,7 @@ > > > #include <linux/interrupt.h> > > > #include <linux/notifier.h> > > > #include <linux/rfkill.h> > > > +#include <linux/crypto.h> > > > #include <net/sock.h> > > > > > > #include <asm/system.h> > > > @@ -961,6 +962,13 @@ int hci_register_dev(struct hci_dev *hdev) > > > if (!hdev->workqueue) > > > goto nomem; > > > > > > + hdev->tfm = crypto_alloc_blkcipher("ecb(aes)", 0, > > > CRYPTO_ALG_ASYNC); > > > + if (IS_ERR(hdev->tfm)) { > > > + BT_ERR("Failed to load transform for ecb(aes): %ld", > > > + PTR_ERR(hdev->tfm)); > > > + goto nomem; > > > + } > > > + > > > hci_register_sysfs(hdev); > > > > > > hdev->rfkill = rfkill_alloc(hdev->name, &hdev->dev, > > > @@ -1001,6 +1009,8 @@ int hci_unregister_dev(struct hci_dev *hdev) > > > for (i = 0; i < NUM_REASSEMBLY; i++) > > > kfree_skb(hdev->reassembly[i]); > > > > > > + crypto_free_blkcipher(hdev->tfm); > > > + > > > hci_notify(hdev, HCI_DEV_UNREG); > > > > > > if (hdev->rfkill) { > > > -- > > > 1.7.3.2 > > > > > > -- > > > To unsubscribe from this list: send the line "unsubscribe linux- > > > bluetooth" in > > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > Cheers, > -- > Vinicius > -- > To unsubscribe from this list: send the line "unsubscribe linux- > bluetooth" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
