Bluetooth: Add flexible buffer byte order swapping function

Since the SMP code needs to swap ordering of variable length buffers add
a convenience function that can be used for any length buffer.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Remove unused LTK authentication defines

These defines were probably put in to track authenticated vs
unauthenticated LTKs, however since the LTK struct has a separate
boolean authenticated member these were never used.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Remove HCI_ prefix from SMP_ LTK defines

The LTK type has really nothing to do with HCI so it makes more sense to
have these in smp.h than hci.h. This patch moves the defines to smp.h
and removes the HCI_ prefix in the same go.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Fix missing hdev locking in smp_cmd_ident_addr_info

The hdev lock must be held before calling into smp_distribute_keys. Also
things such as hci_add_irk() require the lock. This patch fixes the
issue by adding the necessary locking into the smp_cmd_ident_addr_info
function.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Fix locking of hdev when calling into SMP code

The SMP code expects hdev to be unlocked (e.g. crypto functions will try
to (re)lock it) so ensure we release the call before calling into smp.c
from mgmt.c.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Update SMP crypto functions to take a hdev pointer

Passing the full hdev struct instead of just the crypto context allows
us to move the needed locking of hdev into the functions themselves as
well as do more helpful logging in the case of multi-adapter systems.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Add ECC library for LE Secure Connections

This patch adds a simple ECC library that will act as a fundamental
building block for LE Secure Connections. The library has a simple API
consisting of two functions: one for generating a public/private key
pair and another one for generating a Diffie-Hellman key from a local
private key and a remote public key.

The code has been taken from https://github.com/kmackay/easy-ecc and
modified to conform with the kernel coding style.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Add basic support for AES-CMAC

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Add basic SMP defines for LE Secure Connections

This patch adds basic SMP defines for commands, error codes and PDU
definitions for the LE Secure Connections feature.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Extend SMP auth_req mask to include SC bits

In order to make use of the new bits in the authentication request
parameter we need to update the mask used for filtering out reserved
bits.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Update SMP security level to/from auth_req for SC

This patch updates the functions which map the SMP authentication
request to a security level and vice-versa to take into account the
Secure Connections feature.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Add SMP flag for SC and set it when necessary.

This patch adds a new SMP flag for tracking whether Secure Connections
is in use and sets the flag when both remote and local side have elected
to use Secure Connections.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Add crypto functions
Bluetooth: Add mgmt support for LE Secure Connections LTK types

We need a dedicated LTK type for LTK resulting from a Secure Connections
based SMP pairing. This patch adds a new define for it and ensures that
both the New LTK event as well as the Load LTKs command supports it.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Set the correct security level for SC LTKs

When the looked-up LTK is one generated by Secure Connections pairing
the security level it gives is BT_SECURITY_FIPS. This patch updates the
LTK request event handler to correctly set this level.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Add SMP ah_ext() function

This patch adds the ah_ext() function for SMP used by LE Secure
Connections when starting encryption by a central that uses a Resolvable
Private Address.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Use custom macro for testing BR/EDR SC enabled

Since the HCI_SC_ENABLED flag will also be used for controllers without
BR/EDR Secure Connections support whenever we need to check specifically
for SC for BR/EDR we also need to check that the controller actually
supports it. This patch adds a convenience macro for check all the
necessary conditions and converts the places in the code that need it to
use it.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Add mgmt_set_secure_conn support for any LE adapter

Since LE Secure Connections is a purely host-side feature we should
offer the Secure Connections mgmt setting for any adapter with LE
support. This patch updates the supported settings value and the
set_secure_conn command handler accordingly.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Make auth_req mask dependent on SC enabled or not

If we haven't enabled SC support on our side we should use the same mask
for the authentication requirement as we were using before SC support
was added.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Bluetooth: Update LTK lookup to correctly deal with SC LTKs

LTKs derived from Secure Connections based pairing are symmetric, i.e.
they should match both master and slave role. This patch updates the LTK
lookup functions to ignore the desired role when dealing with SC LTKs.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>