If we're encrypted with the STK we should allow re-encryption with an
LTK even though the achieved security level is the same. This patch adds
the necessary logic to the smp_sufficient_security function which is
used to determine whether to proceed with encryption or not.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There are certain subtle differences in behavior when we're encrypted
with the STK, such as allowing re-encryption even though the security
level stays the same. Because of this, add a flag to track whether we're
encrypted with an STK or not.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If we're already encrypted with a good enough LTK we should just ignore
an incoming SMP Security Request. The code was already taking care of
this in the smp_conn_security function before calling smp_ltk_encrypt
but failed to do the same in smp_cmd_security_req. This patch fixes the
issue by moving up the smp_sufficient_security function and using it in
the Security Request handler before trying to request encryption.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The return value of smp_ltk_encrypt is simple boolean, so just use
bool and make the code a bit more readable.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The smp_conn member of struct hci_conn was simply a pointer to the
l2cap_conn object. Since we already have hcon->l2cap_data that points to
the same thing there's no need to have this second variable. This patch
removes it and changes the single place that was using it to use
hcon->l2cap_data instead.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The smp_user_confirm_reply() function is called whenever user space
sends a user confirmation reply mgmt command. In case of a misbehaving
user space, or if the SMP session was removed by the time the command
comes it is important that we return an appropriate error and do not try
to access the non-existent SMP context. This patch adds the appropriate
check for the HCI_CONN_LE_SMP_PEND flag before proceeding further.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Passing the full SMP context instead of just the crypto context lets us
use the crypto handle from the context which in turn removes the need to
lock the hci_dev. Passing the SMP context instead of just the crypto
handle allows a bit more detailed logging which is helpful in
multi-adapter scenarios.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Many places have to be extra careful to not hold the hdev lock when
calling into the SMP code. This is because the SMP crypto functions use
the crypto handle that's part of the hci_dev struct. Giving the SMP
context its own handle helps simplifying the locking logic and removes
the risk for deadlocks.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since the link_mode member of the hci_conn struct is a bit field and we
already have a flags member as well it makes sense to merge these two
together. This patch moves all used link_mode bits into corresponding
flags. To keep backwards compatibility with user space we still need to
provide a get_link_mode() helper function for the ioctl's that expect a
link_mode style value.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There's no reason to have explicit values for these flags. Convert them
to an enum to be consistent with other similar flags.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We never store the "master" type of STKs since we request encryption
directly with them so we only need one STK type (the one that's
looked-up on the slave side). Simply remove the unnecessary define and
rename the _SLAVE one to the shorter form.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The smp_chan_create function may return NULL, e.g. in the case of memory
allocation failure, so we always need to check for this.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If we need an MITM protected connection but the local and remote IO
capabilities cannot provide it we should reject the pairing attempt in
the appropriate way. This patch adds the missing checks for such a
situation to the smp_cmd_pairing_req() and smp_cmd_pairing_rsp()
functions.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We'll need to do authentication method lookups from more than one place,
so refactor the lookup into its own function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When we receive a pairing request or an internal request to start
pairing we shouldn't blindly overwrite the existing pending_sec_level
value as that may actually be higher than the new one. This patch fixes
the SMP code to only overwrite the value in case the new one is higher
than the old.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When we store the STK in slave role we should set the correct
authentication information for it. If the pairing is producing a HIGH
security level the STK is considered authenticated, and otherwise it's
considered unauthenticated. This patch fixes the value passed to the
hci_add_ltk() function when adding the STK on the slave side.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Tested-by: Marcin Kraglak <marcin.kraglak@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
Due to recent changes to the way that the MITM requirement is set for
outgoing pairing attempts we can no longer rely on the hcon->auth_type
variable (which is actually good since it was formed from BR/EDR
concepts that don't really exist for SMP).
To match the logic that BR/EDR now uses simply rely on the local IO
capability and/or needed security level to set the MITM requirement for
outgoing pairing requests.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
Now that smp_confirm() is called "inline" we can have it return a
response code and have the sending of it be done in the shared place for
command handlers. One exception is when we're entering smp.c from mgmt.c
when user space responds to authentication, in which case we still need
our own code to call smp_failure().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since we're now calling smp_random() "inline" we can have it directly
return a response code and have the shared command handler send the
response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There's no reason to have "smp" in this variable name since it is
already part of the SMP struct which provides sufficient context.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the SMP code was initially created (mid-2011) parts of the
Bluetooth subsystem were still not converted to use workqueues. This
meant that the crypto calls, which could sleep, couldn't be called
directly. Because of this the "confirm" and "random" work structs were
introduced.
These days the entire Bluetooth subsystem runs through workqueues which
makes these structs unnecessary. This patch removes them and converts
the calls to queue them to use direct function calls instead.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There is no reason to have the initial local value conditional to
whether the remote value has bonding set or not. We can either way start
off with the value we received.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There are no users of the smp_chan struct outside of smp.c so move it
away from smp.h. The addition of the l2cap.h include to hci_core.c,
hci_conn.c and mgmt.c is something that should have been there already
previously to avoid warnings of undeclared struct l2cap_conn, but the
compiler warning was apparently shadowed away by the mention of
l2cap_conn in the struct smp_chan definition.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The Invalid Parameters error code is used to indicate that the command
length is invalid or that a parameter is outside of the specified range.
This error code wasn't clearly specified in the Bluetooth 4.0
specification but since 4.1 this has been fixed.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The smp variable in smp_conn_security is not used anywhere before the
smp = smp_chan_create() call in the smp_conn_security function so it
makes no sense to assign any other value to it before that.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The smp pointer might not be initialized for jumps to the "done" label
in the smp_conn_security function. Furthermore doing the set_bit after
done might "overwrite" a previous value of the flag in case pairing was
already in progress. This patch moves the call to set_bit before the
label so that it is only done for a newly created smp context (as
returned by smp_chan_create).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Due to several devices being unable to handle this procedure reliably
(resulting in forced disconnections before pairing completes) it's
better to remove it altogether.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In the case that the just-works model would be triggered we only want to
confirm remotely initiated pairings (i.e. those triggered by a Security
Request or Pairing Request). This patch adds the necessary check to the
tk_request function to fall back to the JUST_WORKS method in the case of
a locally initiated pairing.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
For remotely initiated just-works pairings we want to show the user a
confirmation dialog for the pairing. However, we can only know which
side was the initiator by tracking which side sends the first Security
Request or Pairing Request PDU. This patch adds a new SMP flag to
indicate whether our side was the initiator for the pairing.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In the case that a local pairing confirmation (JUST_CFM) has been
selected as the method we need to use the user confirm request mgmt
event for it with the confirm_hint set to 1 (to indicate confirmation
without any specific passkey value). Without this (if passkey_notify was
used) the pairing would never proceed. This patch adds the necessary
call to mgmt_user_confirm_request in this scenario.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We need to ensure that we do not send events to user space with the
identity address if we have not yet notified user space of the IRK. The
code was previously trying to handle this for the mgmt_pair_device
response (which worked well enough) but this is not the only connection
related event that might be sent to user space before pairing is
successful: another important event is Device Disconnected.
The issue can actually be solved more simply than the solution
previously used for mgmt_pair_device. Since we do have the identity
address tracked as part of the remote IRK struct we can just copy it
over from there to the hci_conn struct once we've for real sent the mgmt
event for the new IRK.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The passkey_notify and user_confirm functions in mgmt.c were expecting
different endianess for the passkey, leading to a big endian bug and
sparse warning in recently added SMP code. This patch converts both
functions to expect host endianess and do the conversion to little
endian only when assigning to the mgmt event struct.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When performing SMP pairing with MITM protection one side needs to
enter the passkey while the other side displays to the user what needs
to be entered. Nowhere in the SMP specification does it say that the
displaying side needs to any kind of confirmation of the passkey, even
though a code comment in smp.c implies this.
This patch removes the misleading comment and converts the code to use
the passkey notification mgmt event instead of the passkey confirmation
mgmt event.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This is a trivial coding style simplification by instead of having an
extra early return to instead revert the if condition and do the single
needed queue_work() call there.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The pairing process initiated through mgmt sets the conn->auth_type
value regardless of BR/EDR or LE pairing. This value will contain the
MITM flag if the local IO capability allows it. When sending the SMP
pairing request we should check the value and ensure that the MITM bit
gets correctly set in the bonding flags.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The SMP specification is written with the assumption that both key
information, plaintextData and encryptedData follow the same little
endian byte ordering as the rest of SMP.
Since the kernel crypto routines expect big endian data the code has had
to do various byte swapping tricks to make the behavior as expected,
however the swapping has been scattered all around the place.
This patch centralizes the byte order swapping into the smp_e function
by making its public interface match what the other SMP functions expect
as per specification. The benefit is vastly simplified calls to smp_e.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To make it possible to (correctly) pass data declared as const as the
src parameter to the swap56 and swap128 functions declare this parameter
also as const.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When performing pairing using SMP the remote may clear any key
distribution bits it wants in its pairing response. We must therefore
update our local variable accordingly, otherwise we might get stuck
waiting for keys that will never come.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The use of __constant_<foo> has been unnecessary for quite awhile now.
Make these uses consistent with the rest of the kernel.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In case the pairable option has been disabled, the pairing procedure
does not create keys for bonding. This means that these generated keys
should not be stored persistently.
For LTK and CSRK this is important to tell userspace to not store these
new keys. They will be available for the lifetime of the device, but
after the next power cycle they should not be used anymore.
Inform userspace to actually store the keys persistently only if both
sides request bonding.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The connection signature resolving key (CSRK) is used for attribute
protocol signed write procedures. This change generates a new local
key during pairing and requests the peer key as well.
Newly generated key and received key will be provided to userspace
using the New Signature Resolving Key management event.
The Master CSRK can be used for verification of remote signed write
PDUs and the Slave CSRK can be used for sending signed write PDUs
to the remote device.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Some devices may refuse to re-encrypt with the LTK if they haven't
received all our keys yet. This patch adds a 250ms delay before
attempting re-encryption with the LTK.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
It's not strictly speaking required to re-encrypt a link once we receive
an LTK since the connection is already encrypted with the STK. However,
re-encrypting with the LTK allows us to verify that we've received an
LTK that actually works.
This patch updates the SMP code to request encrypting with the LTK in
case we're in master role and waits until the key refresh complete event
before notifying user space of the distributed keys.
A new flag is also added for the SMP context to ensure that we
re-encryption only once in case of multiple calls to smp_distribute_keys.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that we have nicely tracked values of the initiator and responder
address information we can pass that directly to the smp_c1 function
without worrying e.g. about who initiated the connection. This patch
updates the two places in smp.c to use the new variables.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If SMP fails we should not leave any keys (LTKs or IRKs) hanging around
the internal lists. This patch adds the necessary code to
smp_chan_destroy to remove any keys we may have in case of pairing
failure.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The random numbers in Bluetooth Low Energy are 64-bit numbers and should
also be little endian since the HCI specification is little endian.
Change the whole Low Energy pairing to use __le64 instead of a byte
array.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
