Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
net/bluetooth/smp.c:2650:9-16: WARNING: ERR_CAST can be used with tfm_aes
Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))
Generated by: scripts/coccinelle/api/err_cast.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The SMP over BR/EDR requests for cross-transport pairing should also
accepted when the debugfs setting force_lesc_support has been enabled.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Some gcc versions don't seem to be able to properly track the flow of
the smp_cmd_pairing_random() function and end up causing the following
types of (false-positive) warnings:
smp.c:1995:6: warning: ‘nb’ may be used uninitialized in this function [-Wmaybe-uninitialized]
err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
smp.c:1995:6: warning: ‘na’ may be used uninitialized in this function [-Wmaybe-uninitialized]
err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
^
smp.c:1995:6: warning: ‘pkbx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
^
smp.c:1995:6: warning: ‘pkax’ may be used uninitialized in this function [-Wmaybe-uninitialized]
err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
This patch fixes the issue by moving the pkax/pkbx and na/nb
initialization earlier in the function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The convention for checking for NULL pointers is !ptr and not
ptr == NULL. This patch fixes such an occurrence in smp.c.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We need to keep debug keys around at least until the point that they are
used - otherwise e.g. slave role behavior wouldn't work as there'd be no
key to be looked up. The correct behavior should therefore be to return
any stored keys but when we clean up the SMP context to remove the key
from the hdev list if keeping debug keys around hasn't been requestsed.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch organizes the various SMP crypto functions so that the LE SC
functions appear in one section and the legacy SMP functions in a
separate one.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Several SMP functions take read-only data. This patch fixes the
declaration of these parameters to use the const specifier as
appropriate.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The various inputs & outputs of the crypto functions as well as the
values of the ECDH keys can be considered security sensitive. They
should therefore not end up in dmesg by mistake. This patch introduces a
new SMP_DBG macro which requires explicit compilation with -DDEBUG to be
enabled. All crypto related data logs now use this macro instead of
BT_DBG.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds basic OOB pairing support when we've received the remote
OOB data. This includes tracking the remote r value (in smp->rr) as well
as doing the appropriate f4() call when needed. Previously the OOB rand
would have been stored in smp->rrnd however these are actually two
independent values so we need separate variables for them. Na/Nb in the
spec maps to smp->prnd/rrnd and ra/rb maps to smp->rr with smp->pr to
come once local OOB data is supported.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If we have OOB data available for the remote device in question we
should set the OOB flag appropriately in the SMP pairing request or
response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When Secure Connections-only mode is enabled we should reject any
pairing command that does not have Secure Connections set in the
authentication requirements. This patch adds the appropriate logic for
this to the command handlers of Pairing Request/Response and Security
Request.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When doing SMP over BR/EDR some of the routines can be shared with the
LE functionality whereas others needs to be split into their own BR/EDR
specific branches. This patch implements the split of BR/EDR specific
SMP code from the LE-only code, making sure SMP over BR/EDR works as
specified.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds the very basic code for creating and destroying SMP
L2CAP channels for BR/EDR connections.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The HCI_USE_DEBUG_KEYS flag is intended to force our side to always use
debug keys for pairing. This means both BR/EDR SSP as well as SMP with
LE Secure Connections. This patch updates the SMP code to use the debug
keys instead of generating a random local key pair when the flag is set.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since we don not actively try to clear the keypress notification bit we
might get these PDUs. To avoid failing the pairing process add a simple
dummy handler for these for now.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
According to the LE SC specification the initiating device sends its
DHKey check first and the non-initiating devices sends its DHKey check
as a response to this. It's also important that the non-initiating
device doesn't send the response if it's still waiting for user input.
In order to synchronize all this a new flag is added.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The passkey entry mechanism involves either both sides requesting the
user for a passkey, or one side requesting the passkey while the other
one displays it. The behavior as far as SMP PDUs are concerned are
considerably different from numeric comparison and therefore requires
several new functions to handle it.
In essence passkey entry involves both sides gradually committing to
each bit of the passkey which involves 20 rounds of pairing confirm and
pairing random PDUS being sent in both directions.
This patch adds a new smp->passkey_round variable to track the current
round of the passkey commitment and reuses the variables already present
in struct hci_conn for the passkey and entered key count.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We need to set the correct Link Key type based on the properties of the
LE SC pairing that it was derived from. If debug keys were used the type
should be a debug key, and the authenticated vs unauthenticated
information should be set on what kind of security level was reached.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If the just-works method was chosen we shouldn't send anything to user
space but simply proceed with sending the DHKey Check PDU. This patch
adds the necessary code for it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
After generating the LTK we should set the correct type (normal SC or
debug) and authentication information for it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
It is very unlikely, but to have a 100% guarantee of the generated key
type we need to reject any keys which happen to match the debug key.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We need to be able to detect if the remote side used a debug key for the
pairing. This patch adds the debug key defines and sets a flag to
indicate that a debug key was used. The debug private key (debug_sk) is
also added in this patch but will only be used in a subsequent patch
when local debug key support is implemented.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds code to select the authentication method for Secure
Connections based on the local and remote capabilities. A new
DSP_PASSKEY method is also added for displaying the passkey - something
that is not part of legacy SMP pairing.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
For Secure Connections we'll select the authentication method as soon as
we receive the public key, but only use it later (both when actually
triggering the method as well as when determining the quality of the
resulting LTK). Store the method therefore in the SMP context.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
As the last step of the LE SC pairing process it's time to generate and
distribute keys. The generation part is unique to LE SC and so this
patch adds a dedicated function for it. We also clear the distribution
bits for keys which are not distributed with LE SC, so that the code
shared with legacy SMP will not go ahead and try to distribute them.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Once we receive the DHKey check PDU it's time to first verify that the
value is correct and then proceed with encrypting the link.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
With LE SC, once the user has responded to the numeric comparison it's
time to send DHKey check values in both directions. The DHKey check
value is generated using new smp_f5 and smp_f6 cryptographic functions.
The smp_f5 function is responsible for generating the LTK and the MacKey
values whereas the smp_f6 function takes the MacKey as input and
generates the DHKey Check value.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
After the Pairing Confirm and Random PDUs have been exchanged in LE SC
it's time to generate a numeric comparison value using a new smp_g2
cryptographic function (which also builds on AES-CMAC). This patch adds
the smp_g2 implementation and updates the Pairing Random PDU handler to
proceed with the value genration and user confirmation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When LE SC is being used we should always respond to it by sending our
local random number. This patch adds a convenience function for it which
also contains a check for the pre-requisite public key exchange
completion
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Once the public key exchange is complete the next step is for the
non-initiating device to send a SMP Pairing Confirm PDU to the
initiating device. This requires the use of a new smp_f4 confirm value
generation function which in turn builds on the AES-CMAC cryptographic
function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds a handler function for the LE SC SMP Public Key PDU.
When we receive the key we proceed with generating the shared DHKey
value from the remote public key and local private key.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the initial pairing request & response PDUs have been exchanged and
both have had the LE SC bit set the next step is to generate a ECDH
key pair and to send the public key to the remote side. This patch adds
basic support for generating the key pair and sending the public key
using the new Public Key SMP PDU. It is the initiating device that sends
the public key first and the non-initiating device responds by sending
its public key respectively (in a subsequent patch).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Most of the LE Secure Connections SMP crypto functions build on top of
the AES-CMAC function. This patch adds access to AES-CMAC in the kernel
crypto subsystem by allocating a crypto_hash handle for it in a similar
way that we have one for AES-CBC.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Depending on whether Secure Connections is enabled or not we may need to add
the link key generation bit to the key distribution. This patch does the
necessary modifications to the build_pairing_cmd() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that hci_find_ltk_by_addr is the only LTK lookup function there's no
need to keep the long name anymore. This patch shortens the function
name to simply hci_find_ltk.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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, otherwise we should use the extended mask for SC.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that the SMP related key lists are converted to RCU there is nothing
in smp_cmd_sign_info() or smp_cmd_ident_addr_info() that would require
taking the hdev lock (including the smp_distribute_keys call). This
patch removes this unnecessary locking.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch set converts the hdev->identity_resolving_keys list to use
RCU to eliminate the need to use hci_dev_lock/unlock.
An additional change that must be done is to remove use of
CRYPTO_ALG_ASYNC for the hdev-specific AES crypto context. The reason is
that this context is used for matching RPAs and the loop that does the
matching is under the RCU read lock, i.e. is an atomic section which
cannot sleep.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch set converts the hdev->long_term_keys list to use RCU to
eliminate the need to use hci_dev_lock/unlock.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
So far smp_sufficient_security() has returned false if we're encrypted
with an STK but do have an LTK available. However, for the sake of LE
CoC servers we do want to let the incoming connection through even
though we're only encrypted with the STK.
This patch adds a key preference parameter to smp_sufficient_security()
with two possible values (enum used instead of bool for readability).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
By default lockdep considers all L2CAP channels equal. This would mean
that we get warnings if a channel is locked when another one's lock is
tried to be acquired in the same thread. This kind of inter-channel
locking dependencies exist in the form of parent-child channels as well
as any channel wishing to elevate the security by requesting procedures
on the SMP channel.
To eliminate the chance for these lockdep warnings we introduce a
nesting level for each channel and use that when acquiring the channel
lock. For now there exists the earlier mentioned three identified
categories: SMP, "normal" channels and parent channels (i.e. those in
BT_LISTEN state). The nesting level is defined as atomic_t since we need
access to it before the lock is actually acquired.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The mgmt_user_passkey_request and related functions do not do anything
else except read access to hdev->id. This member never changes after the
hdev creation so there is no need to acquire a lock to read it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This reverts commits c6992e9ef2 and
4cd3362da8.
The reason for the revert is that we cannot have more than one module
initialization function and the SMP one breaks the build with modular
kernels. As the proper fix for this is right now looking non-trivial
it's better to simply revert the problematic patches in order to keep
the upstream tree compilable.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds self-tests for the c1 and s1 crypto functions used for
SMP pairing. The data used is the sample data from the core
specification.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds a basic skeleton for SMP self-tests. The tests are put
behind a new configuration option since running them will slow down the
boot process. For now there are no actual tests defined but those will
come in a subsequent patch.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In order to make unit testing possible we need to make the SMP crypto
functions only take the crypto context instead of the full SMP context
(the latter would require having hci_dev, hci_conn, l2cap_chan,
l2cap_conn, etc around). The drawback is that we no-longer get the
involved hdev in the debug logs, but this is really the only way to make
simple unit tests for the code.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We can only determine the final security level when both pairing request
and response have been exchanged. When initiating pairing the starting
target security level is set to MEDIUM unless explicitly specified to be
HIGH, so that we can still perform pairing even if the remote doesn't
have MITM capabilities. However, once we've received the pairing
response we should re-consult the remote and local IO capabilities and
upgrade the target security level if necessary.
Without this patch the resulting Long Term Key will occasionally be
reported to be unauthenticated when it in reality is an authenticated
one.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
This is a trivial change to use a proper define for the NoInputNoOutput
IO capability instead of hard-coded values.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There are several places that need to determine the security level that
an LTK can provide. This patch adds a convenience function for this to
help make the code more readable.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the local IO capability is NoInputNoOutput any attempt to convert
the remote authentication requirement to a target security level is
futile. This patch makes sure that we set the target security level at
most to MEDIUM if the local IO capability is NoInputNoOutput.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
All the cases where we mark SMP commands as dissalowed are their
respective command handlers. We can therefore simplify the code by
always clearing the bit immediately after testing it. This patch
converts the corresponding test_bit() call to a test_and_clear_bit()
call and also removes the now unused SMP_DISALLOW_CMD macro.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The SMP specification states that we should ignore any unknown bits from
the authentication requirement. We already have a define for masking out
unknown bits but we haven't used it in all places so far. This patch
adds usage of the AUTH_REQ_MASK to all places that need it and ensures
that we don't pass unknown bits onward to other functions.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We do nothing else with the auth variable in smp_cmd_pairing_rsp()
besides passing it to tk_request() which in turn only cares about
whether one of the sides had the MITM bit set. It is therefore
unnecessary to assign a value to it until just before calling
tk_request(), and this value can simply be the bit-wise or of the local
and remote requirements.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If the remote side is not distributing its IRK but is distributing the
CSRK the next PDU after master identification is the Signing
Information. This patch fixes a missing SMP_ALLOW_CMD() for this in the
smp_cmd_master_ident() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Whether through HCI with BR/EDR or SMP with LE when authentication fails
we should also notify any pending Pair Device mgmt command. This patch
updates the mgmt_auth_failed function to take the actual hci_conn object
and makes sure that any pending pairing command is notified and cleaned
up appropriately.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch fixes the following type of static analyzer warning (and
probably a real bug as well as the NULL check should be there for a
reason):
net/bluetooth/smp.c:1182 smp_conn_security() warn: variable dereferenced before check 'conn' (see line 1174)
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
SMP defines quite clearly when certain PDUs are to be expected/allowed
and when not, but doesn't have any explicit request/response definition.
So far the code has relied on each PDU handler to behave correctly if
receiving PDUs at an unexpected moment, however this requires many
different checks and is prone to errors.
This patch introduces a generic way to keep track of allowed PDUs and
thereby reduces the responsibility & load on individual command
handlers. The tracking is implemented using a simple bit-mask where each
opcode maps to its own bit. If the bit is set the corresponding PDU is
allow and if the bit is not set the PDU is not allowed.
As a simple example, when we send the Pairing Request we'd set the bit
for Pairing Response, and when we receive the Pairing Response we'd
clear the bit for Pairing Response.
Since the disallowed PDU rejection is now done in a single central place
we need to be a bit careful of which action makes most sense to all
cases. Previously some, such as Security Request, have been simply
ignored whereas others have caused an explicit disconnect.
The only PDU rejection action that keeps good interoperability and can
be used for all the applicable use cases is to drop the data. This may
raise some concerns of us now being more lenient for misbehaving (and
potentially malicious) devices, but the policy of simply dropping data
has been a successful one for many years e.g. in L2CAP (where this is
the *only* policy for such cases - we never request disconnection in
l2cap_core.c because of bad data). Furthermore, we cannot prevent
connected devices from creating the SMP context (through a Security or
Pairing Request), and once the context exists looking up the
corresponding bit for the received opcode and deciding to reject it is
essentially an equally lightweight operation as the kind of rejection
that l2cap_core.c already successfully does.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When we're in the process of receiving keys in phase 3 of SMP we keep
track of which keys are still expected in the smp->remote_key_dist
variable. If we still have some key bits set we need to continue waiting
for more PDUs and not needlessly call smp_distribute_keys(). This patch
fixes two such cases in the smp_cmd_master_ident() and
smp_cmd_ident_addr_info() handler functions.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds a define for the allowed bits of the key distribution
mask so we don't have to have magic 0x07 constants throughout the code.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Before the move the l2cap_chan the SMP context (smp_chan) didn't have
any kind of proper locking. The best there existed was the
HCI_CONN_LE_SMP_PEND flag which was used to enable mutual exclusion for
potential multiple creators of the SMP context.
Now that SMP has been converted to use the l2cap_chan infrastructure and
since the SMP context is directly mapped to a corresponding l2cap_chan
we get the SMP context locking essentially for free through the
l2cap_chan lock. For all callbacks that l2cap_core.c makes for each
channel implementation (smp.c in the case of SMP) the l2cap_chan lock is
held through l2cap_chan_lock(chan).
Since the calls from l2cap_core.c to smp.c are covered the only missing
piece to have the locking implemented properly is to ensure that the
lock is held for any other call path that may access the SMP context.
This means user responses through mgmt.c, requests to elevate the
security of a connection through hci_conn.c, as well as any deferred
work through workqueues.
This patch adds the necessary locking to all these other code paths that
try to access the SMP context. Since mutual exclusion for the l2cap_chan
access is now covered from all directions the patch also removes
unnecessary HCI_CONN_LE_SMP_PEND flag (once we've acquired the chan lock
we can simply check whether chan->smp is set to know if there's an SMP
context).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that the identity address update happens through its own deferred
work there's no need to have smp_distribute_keys anymore behind a second
deferred work. This patch removes this extra construction and makes the
code do direct calls to smp_distribute_keys() again.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The identity address update of all channels for an l2cap_conn needs to
take the lock for each channel, i.e. it's safest to do this by a
separate workqueue callback.
Previously this was partially solved by moving the entire SMP key
distribution behind a workqueue. However, if we want SMP context locking
to be correct and safe we should always use the l2cap_chan lock when
accessing it, meaning even smp_distribute_keys needs to take that lock
which would once again create a dead lock when updating the identity
address.
The simplest way to solve this is to have l2cap_conn manage the deferred
work which is what this patch does. A subsequent patch will remove the
now unnecessary SMP key distribution work struct.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When smp_resume_cb is called if we're not encrypted (i.e. the callback
wasn't called because the connection became encrypted) we shouldn't take
any action at all. This patch moves also the security_timer cancellation
behind this condition.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The SMP security timer used to be able to modify the SMP context state
but now days it simply calls hci_disconnect(). It is therefore
unnecessary to have extra sanity checks for the SMP context after
canceling the timer.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Returning failure from the SMP data parsing function will cause an
immediate disconnect, making any attempts to send a response PDU futile.
This patch updates the function to always either send a response or
return an error, but never both at the same time:
* In the case that HCI_LE_ENABLED is not set we want to send a Pairing Not
Supported response but it is not required to force a disconnection, so
do not set the error return in this case.
* If we get garbage SMP data we can just fail with the handler function
instead of also trying to send an SMP Failure PDU.
* There's no reason to force a disconnection if we receive an unknown SMP
command. Instead simply send a proper Command Not Supported SMP
response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Relying on the l2cap_conn_del procedure (triggered through the
l2cap_conn_shutdown API) to get the connection disconnected is not
reliable as it depends on all users releasing (through hci_conn_drop)
and that there's at least one user (so hci_conn_drop is called at least
one time).
A much simpler and more reliable solution is to call hci_disconnect()
directly from the SMP code when we want to disconnect. One side-effect
this has is that it prevents any SMP Failure PDU from being sent before
the disconnection, however neither one of the scenarios where
l2cap_conn_shutdown was used really requires this.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There are no external users of smp_chan_destroy() so make it private to
smp.c. The patch also moves the function higher up in the c-file in
order to avoid forward declarations.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The smp_distribute_keys() function calls smp_notify_keys() which in turn
calls l2cap_conn_update_id_addr(). The l2cap_conn_update_id_addr()
function will iterate through all L2CAP channels for the respective
connection: lock the channel, update the address information and unlock
the channel.
Since SMP is now using l2cap_chan callbacks each callback is called with
the channel lock held. Therefore, calling l2cap_conn_update_id_addr()
would cause a deadlock calling l2cap_chan_lock() on the SMP channel.
This patch moves calling smp_distribute_keys() through a workqueue so
that it is never called from an L2CAP channel callback.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
All places needing to cancel the security timer also call
smp_chan_destroy() in the same go. To eliminate the need to do these two
calls in multiple places simply move the timer cancellation into
smp_chan_destroy().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds an SMP-internal timeout callback to remove the depenency
on (the soon to be removed) l2cap_conn->security_timer. The behavior is
the same as with l2cap_conn->security_timer except that the new
l2cap_conn_shutdown() public function is used instead of the L2CAP core
internal l2cap_conn_del().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In the case that the SMP recv callback returns error the calling code in
l2cap_core.c expects that it still owns the skb and will try to free it.
The SMP code should therefore not try to free the skb if it return an
error. This patch fixes such behavior in the SMP command handler
function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To restore pre-l2cap_chan functionality we should be trying to
disconnect the connection when receviving garbage SMP data (i.e. when
the SMP command handler fails). This patch renames the command handler
back to smp_sig_channel() and adds a smp_recv_cb() wrapper function for
calling it. If smp_sig_channel() fails the code calls
l2cap_conn_shutdown().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There's no need to export the smp_distribute_keys() function since the
resume callback is called in the same scenario. This patch makes the
smp_notify_keys function private (at the same time moving it higher up
in smp.c to avoid forward declarations) and adds a resume callback for
SMP to call it from there instead.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that we have all the necessary pieces in place we can fully convert
SMP to use the L2CAP channel infrastructure. This patch adds the
necessary callbacks and removes the now unneeded conn->smp_chan pointer.
One notable behavioral change in this patch comes from the following
code snippet:
- case L2CAP_CID_SMP:
- if (smp_sig_channel(conn, skb))
- l2cap_conn_del(conn->hcon, EACCES);
This piece of code was essentially forcing a disconnection if garbage
SMP data was received. The l2cap_conn_del() function is private to
l2cap_conn.c so we don't have access to it anymore when using the L2CAP
channel callbacks. Therefore, the behavior of the new code is simply to
return errors in the recv() callback (which is simply the old
smp_sig_channel()), but no disconnection will occur.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that we have per-adapter SMP data thanks to the root SMP L2CAP
channel we can take advantage of it and attach the AES crypto context
(only used for SMP) to it. This means that the smp_irk_matches() and
smp_generate_rpa() function can be converted to internally handle the
AES context.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch creates the initial SMP L2CAP channels and a skeleton for
their callbacks. There is one per-adapter channel created upon adapter
registration, and then one channel per-connection created through the
new_connection callback. The channels are registered with the reserved
CID 0x1f for now in order to not conflict with existing SMP
functionality. Once everything is in place the value can be changed to
what it should be, i.e. L2CAP_CID_SMP.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
As preparation for moving SMP to use l2cap_chan infrastructure we need
to move the (de)initialization functions to smp.c (where they'll
eventually need access to the local L2CAP channel callbacks).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The code is consistently using the HCI_CONN_LE_SMP_PEND flag check for
the existence of the SMP context, with the exception of this one place
in smp_sig_channel(). This patch converts the place to use the flag just
like all other instances.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In the smp_cmd_sign_info() function the SMP_DIST_SIGN bit is explicitly
cleared early on in the function. This means that there's no need to
check for it again before calling smp_distribute_keys().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The HCI_PAIRABLE flag isn't actually controlling whether we're pairable
but whether we're bondable. Therefore, rename it accordingly.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Devices using resolvable private addresses are required to provide
an identity resolving key. These devices can not be found using
the current controller white list support. This means if the kernel
knows about any devices with an identity resolving key, the white
list filtering must be disabled.
However so far the kernel kept identity resolving keys around even
for devices that are not using resolvable private addresses. The
notification to userspace clearly hints to not store the key and
so it is best to just remove the key from the kernel as well at
that point.
With this it easy now to detect when using the white list is
possible or when kernel side resolving of addresses is required.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The EOPNOTSUPP and ENOTSUPP errors are very similar in meaning, but
ENOTSUPP is a fairly new addition to POSIX. Not all libc versions know
about the value the kernel uses for ENOTSUPP so it's better to use
EOPNOTSUPP to ensure understandable error messages.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If user space has a NoInputNoOutput IO capability it makes no sense to
bother it with confirmation requests. This patch updates both SSP and
SMP to check for the local IO capability before sending a user
confirmation request to user space.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To make the code more understandable it makes sense to use the new HCI
defines for connection role instead of a "bool master" parameter. This
makes it immediately clear when looking at the function calls what the
last parameter is describing.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Having a dedicated u8 role variable in the hci_conn struct greatly
simplifies tracking of the role, since this is the native way that it's
represented on the HCI level.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In the case that the key distribution bits cause us not to generate a
local LTK we should not try to re-encrypt if we're currently encrypted
with an STK. This patch fixes the check for this in the
smp_sufficient_security function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If the remote device tries to initiate bonding with us and we don't have
HCI_PAIRABLE set we should just flat out reject the request. This brings
SMP in line with how the flag is used for BR/EDR SSP.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the SMP context is created all flags default to zero. To determine
that we are the initiators it's therefore best to simply change the flag
value when we know we're sending the first SMP PDU. Clearing the flag
when receiving a Pairing Request is not correct since the request may be
a response to a previous Security Request from us (for which we would
already have correctly set the flag). Same goes for receiving a Security
Request which may be coming after us already starting pairing by sending
a Pairing Request.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Whether we bond or not should not have any impact on the user
interaction model. This patch removes an incorrect fall-back from
JUST_CFM to JUST_WORKS in case we're not bonding.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
For incoming requests we want to let the user know that pairing is
happening since otherwise there could be access to MEDIUM security
services without any user interaction at all. Therefore, set the
selected method to JUST_CFM instead of JUST_WORKS and let it be
converted back to JUST_WORKS later if we are the initators.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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>
Now that to-be-received keys are properly tracked we no-longer need the
"force" parameter to smp_distribute_keys(). It was essentially acting as
an indicator whether all keys have been received, but now it's just
redundant together with smp->remote_key_dist.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that smp->remote_key_dist is tracking the keys we're still waiting
for we can use it to simplify the logic for checking whether we're done
with key distribution or not. At the same time the reliance on the
"force" parameter of smp_distribute_keys goes away and it can completely
be removed in a subsequent patch.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To make is easier to track which keys we've received and which ones
we're still waiting for simply clear the corresponding key bits from
smp->remote_key_dist as they get received. This will allow us to
simplify the code for checking for SMP completion in subsequent patches.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The Core Specification (4.1) leaves room for sending an SMP Identity
Address Information PDU with an all-zeros BD_ADDR value. This
essentially means that we would not have an Identity Address for the
device and the only means of identifying it would be the IRK value
itself.
Due to lack of any known implementations behaving like this it's best to
keep our implementation as simple as possible as far as handling such
situations is concerned. This patch updates the Identity Address
Information handler function to simply ignore the IRK received from such
a device.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We need a function in smp.c to generate Resolvable Random Addresses in
order to support privacy. The local RPA will need to be generated before
advertising, scanning or connecting and regenerated at periodic
intervals. This patch adds the necessary function for RPA generation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Al Viro