Hi Vinicius, On Mon, Jan 24, 2011 at 11:34 PM, Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxxxxxx> wrote: > Hi Brian, > > On 11:03 Mon 24 Jan, Brian Gix wrote: >> Hi Vinicius, >> >> I am sorry that it has taken so long to test the snapshot that you >> placed on gitorious, but I have now done so. >> >> On Fri, 2010-12-03 at 19:05 -0300, Vinicius Costa Gomes wrote: >> > Hi Brian, >> > >> > On 11:11 Fri 03 Dec, Brian Gix wrote: >> > > >> > > Hi Claudio, Johan & All, >> > > >> > > Is this LE capable kernel that Ville is working on, the development stream >> > > for the LE Security Manager? And if so, is it in a partial fleshed out >> > > state? >> > >> > There is a simple implementation of SMP here[1] on my "devel" branch. I am >> > cleaning it up for sending it for review. >> > >> > If you want to help, have any comments or just want to tell us what you are >> > working on, please drop by #bluez on freenode, or send an email. >> >> I have been able to verify that the Just Works negotiation of the Short >> Term Key does work against an independent implementation of the LE >> Security Manager, as long as I have requested no MITM protection. I >> have the following comments: >> >> 1. You currently reject security if I *do* request MITM protection. >> This should not be done. The correct functionality should be to >> continue the negotiation. Even though I requested MITM, it will be >> clear to both sides that JUST_WORKS methodology has been used, and so >> when the Keys are generated and exchanged, both sides will indicate in >> their Key Database that they are no-MITM keys. If I then actually >> *needed* MITM protection, then whatever functionality requiring that >> level of security will fail with an insufficient security error code. >> However, security should *never* be rejected unless there is a >> fundamental incompatibility such as no level of security actually >> supported. This is the only functionality that I found to be actually >> incorrect. >> > > I was assuming that the meaning of setting the MITM protection bit, was that > it was *requiring* MITM protection, and when that couldn't be fulfilled the > Pairing Request should be rejected. > > So my assumption was incorrect, going to fix it soon. Well the spec says it is a requirement: "If the STK generation method does not result in an STK that provides sufficient security properties then the device shall send the Pairing Failed command with the error code “Authentication Requirements”" - 2.3.5.1 Selecting STK Generation Method - Page 608 In my interpretation this is exactly what should happen when MITM is set but there is no way to generate an authenticated key as Table 2.4: Mapping of IO Capabilities to STK Generation Method suggest, in other words if one of sides has NoInputNoOutput and MITM is set we should return "Authentication Requirements" error. -- Luiz Augusto von Dentz Computer Engineer -- 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
