ARMmbed
/
mbed-os
mirror of https://github.com/ARMmbed/mbed-os.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
mbed-os/features/FEATURE_BLE/source/generic/GenericSecurityManager.cpp

1721 lines
48 KiB
C++
Raw Blame History

/* mbed Microcontroller Library
* Copyright (c) 2017-2018 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "ble/SecurityManager.h"
#include "ble/pal/PalSecurityManager.h"
#include "ble/generic/GenericSecurityManager.h"
#include "ble/generic/MemorySecurityDb.h"
#include "ble/generic/FileSecurityDb.h"
using ble::pal::advertising_peer_address_type_t;
using ble::pal::AuthenticationMask;
using ble::pal::KeyDistribution;
using ble::pal::connection_peer_address_type_t;
namespace ble {
namespace generic {
/* Implements SecurityManager */
////////////////////////////////////////////////////////////////////////////
// SM lifecycle management
//
ble_error_t GenericSecurityManager::init(
bool bondable,
bool mitm,
SecurityIOCapabilities_t iocaps,
const Passkey_t passkey,
bool signing,
const char* db_path
) {
ble_error_t result = _pal.initialize();
if (result != BLE_ERROR_NONE) {
return result;
}
result = init_database(db_path);
if (result != BLE_ERROR_NONE) {
return result;
}
_pal.set_io_capability((io_capability_t::type) iocaps);
if (passkey) {
_pal.set_display_passkey(PasskeyAscii::to_num(passkey));
} else {
_pal.set_display_passkey(0);
}
_legacy_pairing_allowed = true;
bool secure_connections;
_pal.get_secure_connections_support(secure_connections);
_default_authentication.set_bondable(bondable);
_default_authentication.set_mitm(mitm);
_default_authentication.set_secure_connections(secure_connections);
_default_authentication.set_keypress_notification(true);
// FIXME: depends on BR/EDR support
_default_key_distribution.set_link(false);
_default_key_distribution.set_signing(signing);
if (signing) {
init_signing();
}
_connection_monitor.set_connection_event_handler(this);
_signing_monitor.set_signing_event_handler(this);
_pal.set_event_handler(this);
result = init_resolving_list();
if (result != BLE_ERROR_NONE) {
delete _db;
return result;
}
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::setDatabaseFilepath(
const char *db_path
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
/* operation only allowed with no connections active */
for (size_t i = 0; i < MAX_CONTROL_BLOCKS; i++) {
if (_control_blocks[i].connected) {
return BLE_ERROR_OPERATION_NOT_PERMITTED;
}
}
ble_error_t result = init_database(db_path);
if (result != BLE_ERROR_NONE) {
return result;
}
init_resolving_list();
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::reset(void) {
_pal.reset();
SecurityManager::reset();
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::preserveBondingStateOnReset(bool enabled) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
_db->set_restore(enabled);
return BLE_ERROR_NONE;
}
////////////////////////////////////////////////////////////////////////////
// List management
//
ble_error_t GenericSecurityManager::purgeAllBondingState(void) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
_db->clear_entries();
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::generateWhitelistFromBondTable(Gap::Whitelist_t *whitelist) const {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
if (eventHandler) {
if (!whitelist) {
return BLE_ERROR_INVALID_PARAM;
}
_db->generate_whitelist_from_bond_table(
mbed::callback(eventHandler, &::SecurityManager::EventHandler::whitelistFromBondTable),
whitelist
);
}
return BLE_ERROR_NONE;
}
////////////////////////////////////////////////////////////////////////////
// Pairing
//
ble_error_t GenericSecurityManager::requestPairing(connection_handle_t connection) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
if (!_legacy_pairing_allowed && !_default_authentication.get_secure_connections()) {
return BLE_ERROR_INVALID_STATE;
}
set_mitm_performed(connection, false);
update_oob_presence(connection);
AuthenticationMask link_authentication(_default_authentication);
if (cb->mitm_requested) {
link_authentication.set_mitm(true);
}
/* by default the initiator doesn't send any keys other then identity */
KeyDistribution initiator_distribution(
KeyDistribution::KEY_DISTRIBUTION_IDENTITY |
_default_key_distribution.get_link()
);
initiator_distribution.set_signing(
cb->signing_override_default ?
cb->signing_requested :
_default_key_distribution.get_signing()
);
/* if requested the initiator may send all the default keys for later
* use when roles are changed */
if (_master_sends_keys) {
initiator_distribution = _default_key_distribution;
}
KeyDistribution responder_distribution(_default_key_distribution);
if (cb->signing_override_default) {
responder_distribution.set_signing(cb->signing_requested);
}
return _pal.send_pairing_request(
connection,
cb->oob_present,
link_authentication,
initiator_distribution,
responder_distribution
);
}
ble_error_t GenericSecurityManager::acceptPairingRequest(connection_handle_t connection) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
update_oob_presence(connection);
AuthenticationMask link_authentication(_default_authentication);
if (cb->mitm_requested) {
link_authentication.set_mitm(true);
}
KeyDistribution initiator_distribution = cb->get_initiator_key_distribution();
bool master_signing = initiator_distribution.get_signing();
if (_master_sends_keys) {
initiator_distribution &= _default_key_distribution;
} else {
initiator_distribution &= KeyDistribution(
KeyDistribution::KEY_DISTRIBUTION_IDENTITY |
KeyDistribution::KEY_DISTRIBUTION_LINK
);
}
/* signing has to be offered and enabled on the link */
if (master_signing) {
initiator_distribution.set_signing(
cb->signing_override_default ?
cb->signing_requested :
_default_key_distribution.get_signing()
);
}
KeyDistribution responder_distribution(cb->get_responder_key_distribution());
responder_distribution &= _default_key_distribution;
/* signing has to be requested and enabled on the link */
if (responder_distribution.get_signing()) {
responder_distribution.set_signing(
cb->signing_override_default ?
cb->signing_requested :
_default_key_distribution.get_signing()
);
}
return _pal.send_pairing_response(
connection,
cb->oob_present,
link_authentication,
initiator_distribution,
responder_distribution
);
}
ble_error_t GenericSecurityManager::cancelPairingRequest(connection_handle_t connection) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.cancel_pairing(connection, pairing_failure_t::UNSPECIFIED_REASON);
}
ble_error_t GenericSecurityManager::setPairingRequestAuthorisation(bool required) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
_pairing_authorisation_required = required;
return BLE_ERROR_NONE;
}
////////////////////////////////////////////////////////////////////////////
// Feature support
//
ble_error_t GenericSecurityManager::allowLegacyPairing(bool allow) {
_legacy_pairing_allowed = allow;
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::getSecureConnectionsSupport(bool *enabled) {
return _pal.get_secure_connections_support(*enabled);
}
////////////////////////////////////////////////////////////////////////////
// Security settings
//
ble_error_t GenericSecurityManager::setIoCapability(SecurityIOCapabilities_t iocaps) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.set_io_capability((io_capability_t::type) iocaps);
}
ble_error_t GenericSecurityManager::setDisplayPasskey(const Passkey_t passkey) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.set_display_passkey(PasskeyAscii::to_num(passkey));
}
ble_error_t GenericSecurityManager::setAuthenticationTimeout(
connection_handle_t connection,
uint32_t timeout_in_ms
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.set_authentication_timeout(connection, timeout_in_ms / 10);
}
ble_error_t GenericSecurityManager::getAuthenticationTimeout(
connection_handle_t connection,
uint32_t *timeout_in_ms
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
uint16_t timeout_in_10ms;
ble_error_t status = _pal.get_authentication_timeout(connection, timeout_in_10ms);
*timeout_in_ms = 10 * timeout_in_10ms;
return status;
}
ble_error_t GenericSecurityManager::setLinkSecurity(
connection_handle_t connection,
SecurityMode_t securityMode
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
if (cb->encryption_requested) {
return BLE_ERROR_OPERATION_NOT_PERMITTED;
}
switch (securityMode) {
case SECURITY_MODE_ENCRYPTION_OPEN_LINK:
return setLinkEncryption(connection, link_encryption_t::NOT_ENCRYPTED);
case SECURITY_MODE_ENCRYPTION_NO_MITM:
return setLinkEncryption(connection, link_encryption_t::ENCRYPTED);
case SECURITY_MODE_ENCRYPTION_WITH_MITM:
return setLinkEncryption(connection, link_encryption_t::ENCRYPTED_WITH_MITM);
case SECURITY_MODE_SIGNED_NO_MITM:
return getSigningKey(connection, false);
case SECURITY_MODE_SIGNED_WITH_MITM:
return getSigningKey(connection, true);
default:
return BLE_ERROR_INVALID_PARAM;
}
}
ble_error_t GenericSecurityManager::setKeypressNotification(bool enabled) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
_default_authentication.set_keypress_notification(enabled);
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::enableSigning(
connection_handle_t connection,
bool enabled
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return BLE_ERROR_INVALID_PARAM;
}
cb->signing_override_default = true;
if (enabled && !cb->signing_requested && !_default_key_distribution.get_signing()) {
cb->signing_requested = true;
if (flags->csrk_stored) {
/* used the stored ones when available */
_db->get_entry_peer_csrk(
mbed::callback(this, &GenericSecurityManager::set_peer_csrk_cb),
cb->db_entry
);
} else {
/* create keys if needed and exchange them */
init_signing();
if (cb->is_master) {
return requestPairing(connection);
} else {
return slave_security_request(connection);
}
}
} else {
cb->signing_requested = enabled;
}
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::setHintFutureRoleReversal(bool enable) {
_master_sends_keys = enable;
return BLE_ERROR_NONE;
}
////////////////////////////////////////////////////////////////////////////
// Encryption
//
ble_error_t GenericSecurityManager::getLinkEncryption(
connection_handle_t connection,
link_encryption_t *encryption
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return BLE_ERROR_INVALID_PARAM;
}
if (cb->encrypted) {
if (flags->ltk_mitm_protected || cb->mitm_performed) {
if (flags->secure_connections_paired) {
*encryption = link_encryption_t::ENCRYPTED_WITH_SC_AND_MITM;
} else {
*encryption = link_encryption_t::ENCRYPTED_WITH_MITM;
}
} else {
*encryption = link_encryption_t::ENCRYPTED;
}
} else if (cb->encryption_requested) {
*encryption = link_encryption_t::ENCRYPTION_IN_PROGRESS;
} else {
*encryption = link_encryption_t::NOT_ENCRYPTED;
}
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::setLinkEncryption(
connection_handle_t connection,
link_encryption_t encryption
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return BLE_ERROR_INVALID_PARAM;
}
link_encryption_t current_encryption(link_encryption_t::NOT_ENCRYPTED);
getLinkEncryption(connection, &current_encryption);
if (current_encryption == link_encryption_t::ENCRYPTION_IN_PROGRESS) {
return BLE_ERROR_OPERATION_NOT_PERMITTED;
}
if (current_encryption == encryption) {
/* ignore if the link is already at required state*/
} else if (encryption == link_encryption_t::NOT_ENCRYPTED) {
// Fail as it is not permitted to turn down encryption
return BLE_ERROR_OPERATION_NOT_PERMITTED;
} else if (encryption == link_encryption_t::ENCRYPTED) {
/* only change if we're not already encrypted with mitm */
if (current_encryption != link_encryption_t::ENCRYPTED_WITH_MITM ||
current_encryption != link_encryption_t::ENCRYPTED_WITH_SC_AND_MITM
) {
cb->encryption_requested = true;
return enable_encryption(connection);
}
} else if (encryption == link_encryption_t::ENCRYPTED_WITH_MITM) {
if (flags->ltk_mitm_protected && !cb->encrypted) {
cb->encryption_requested = true;
return enable_encryption(connection);
} else {
cb->encryption_requested = true;
return requestAuthentication(connection);
}
} else if (encryption == link_encryption_t::ENCRYPTED_WITH_SC_AND_MITM) {
if (flags->ltk_mitm_protected &&
flags->secure_connections_paired &&
!cb->encrypted
) {
cb->encryption_requested = true;
return enable_encryption(connection);
} else {
cb->encryption_requested = true;
return requestAuthentication(connection);
}
} else {
return BLE_ERROR_INVALID_PARAM;
}
eventHandler->linkEncryptionResult(connection, current_encryption);
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::getEncryptionKeySize(
connection_handle_t connection,
uint8_t *size
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return BLE_ERROR_INVALID_PARAM;
}
*size = flags->encryption_key_size;
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::setEncryptionKeyRequirements(
uint8_t minimumByteSize,
uint8_t maximumByteSize
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.set_encryption_key_requirements(minimumByteSize, maximumByteSize);
}
////////////////////////////////////////////////////////////////////////////
// Keys
//
ble_error_t GenericSecurityManager::getSigningKey(connection_handle_t connection, bool authenticated) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return BLE_ERROR_INVALID_PARAM;
}
if (flags->csrk_stored && (flags->csrk_mitm_protected || !authenticated)) {
/* we have a key that is either authenticated or we don't care if it is
* so retrieve it from the db now */
_db->get_entry_peer_csrk(
mbed::callback(this, &GenericSecurityManager::return_csrk_cb),
cb->db_entry
);
return BLE_ERROR_NONE;
} else {
/* we don't have the right key so we need to get it first
* keys exchange will create the signingKey event */
if (authenticated) {
return requestAuthentication(connection);
} else if (cb->is_master) {
return requestPairing(connection);
} else {
return slave_security_request(connection);
}
}
}
////////////////////////////////////////////////////////////////////////////
// Privacy
//
ble_error_t GenericSecurityManager::setPrivateAddressTimeout(uint16_t timeout_in_seconds) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.set_private_address_timeout(timeout_in_seconds);
}
////////////////////////////////////////////////////////////////////////////
// Authentication
//
ble_error_t GenericSecurityManager::requestAuthentication(connection_handle_t connection) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return BLE_ERROR_INVALID_PARAM;
}
if (flags->ltk_mitm_protected) {
if (cb->authenticated) {
return BLE_ERROR_NONE;
} else {
cb->encryption_requested = true;
return enable_encryption(connection);
}
} else {
cb->mitm_requested = true;
if (cb->is_master) {
return requestPairing(connection);
} else {
return slave_security_request(connection);
}
}
}
////////////////////////////////////////////////////////////////////////////
// MITM
//
ble_error_t GenericSecurityManager::generateOOB(
const address_t *address
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
/* legacy pairing */
ble_error_t status = get_random_data(_oob_temporary_key.data(), 16);
if (status == BLE_ERROR_NONE) {
_oob_temporary_key_creator_address = *address;
eventHandler->legacyPairingOobGenerated(
&_oob_temporary_key_creator_address,
&_oob_temporary_key
);
} else {
return status;
}
/* Secure connections. Avoid generating if we're already waiting for it.
* If a local random is set to 0 it means we're already calculating. */
if (!is_all_zeros(_oob_local_random)) {
status = _pal.generate_secure_connections_oob();
if (status == BLE_ERROR_NONE) {
_oob_local_address = *address;
/* this will be updated when calculation completes,
* a value of all zeros is an invalid random value */
set_all_zeros(_oob_local_random);
} else if (status != BLE_ERROR_NOT_IMPLEMENTED) {
return status;
}
} else {
return BLE_STACK_BUSY;
}
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::setOOBDataUsage(
connection_handle_t connection,
bool useOOB,
bool OOBProvidesMITM
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
cb->attempt_oob = useOOB;
cb->oob_mitm_protection = OOBProvidesMITM;
if (useOOB) {
return generateOOB(&cb->local_address);
} else {
return BLE_ERROR_NONE;
}
}
ble_error_t GenericSecurityManager::confirmationEntered(
connection_handle_t connection,
bool confirmation
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.confirmation_entered(connection, confirmation);
}
ble_error_t GenericSecurityManager::passkeyEntered(
connection_handle_t connection,
Passkey_t passkey
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.passkey_request_reply(
connection,
PasskeyAscii::to_num(passkey)
);
}
ble_error_t GenericSecurityManager::sendKeypressNotification(
connection_handle_t connection,
Keypress_t keypress
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
return _pal.send_keypress_notification(connection, keypress);
}
ble_error_t GenericSecurityManager::legacyPairingOobReceived(
const address_t *address,
const oob_tk_t *tk
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
if (address && tk) {
ControlBlock_t *cb = get_control_block(*address);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return BLE_ERROR_INVALID_PARAM;
}
_oob_temporary_key = *tk;
_oob_temporary_key_creator_address = *address;
if (flags->peer_address == _oob_temporary_key_creator_address) {
cb->attempt_oob = true;
}
if (cb->legacy_pairing_oob_request_pending) {
on_legacy_pairing_oob_request(cb->connection);
/* legacy_pairing_oob_request_pending stops us from
* going into a loop of asking the user for oob
* so this reset needs to happen after the call above */
cb->legacy_pairing_oob_request_pending = false;
}
}
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::oobReceived(
const address_t *address,
const oob_lesc_value_t *random,
const oob_confirm_t *confirm
) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
if (address && random && confirm) {
_oob_peer_address = *address;
_oob_peer_random = *random;
_oob_peer_confirm = *confirm;
return BLE_ERROR_NONE;
}
return BLE_ERROR_INVALID_PARAM;
}
////////////////////////////////////////////////////////////////////////////
// Helper functions
//
ble_error_t GenericSecurityManager::init_database(
const char *db_path
) {
delete _db;
FILE* db_file = FileSecurityDb::open_db_file(db_path);
if (db_file) {
_db = new (std::nothrow) FileSecurityDb(db_file);
} else {
_db = new (std::nothrow) MemorySecurityDb();
}
if (!_db) {
return BLE_ERROR_NO_MEM;
}
_db->restore();
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::init_resolving_list() {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
/* match the resolving list to the currently stored set of IRKs */
uint8_t resolving_list_capacity = _pal.read_resolving_list_capacity();
SecurityEntryIdentity_t* identity_list_p =
new (std::nothrow) SecurityEntryIdentity_t[resolving_list_capacity];
if (identity_list_p) {
ArrayView<SecurityEntryIdentity_t> identity_list(
identity_list_p,
resolving_list_capacity
);
_db->get_identity_list(
mbed::callback(this, &GenericSecurityManager::on_identity_list_retrieved),
identity_list
);
} else {
return BLE_ERROR_NO_MEM;
}
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::init_signing() {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
const csrk_t *pcsrk = _db->get_local_csrk();
sign_count_t local_sign_counter = _db->get_local_sign_counter();
if (!pcsrk) {
csrk_t csrk;
ble_error_t ret = get_random_data(csrk.data(), csrk.size());
if (ret != BLE_ERROR_NONE) {
return ret;
}
pcsrk = &csrk;
_db->set_local_csrk(csrk);
_db->set_local_sign_counter(local_sign_counter);
}
return _pal.set_csrk(*pcsrk, local_sign_counter);
}
ble_error_t GenericSecurityManager::get_random_data(uint8_t *buffer, size_t size) {
byte_array_t<8> random_data;
while (size) {
/* fill out the buffer by reading the random data in chunks
* and copying it until reaching the set size */
size_t copy_size = std::max(size, random_data.size());
ble_error_t ret = _pal.get_random_data(random_data);
if (ret != BLE_ERROR_NONE) {
return ret;
}
memcpy(buffer, random_data.data(), copy_size);
size -= copy_size;
buffer += copy_size;
}
return BLE_ERROR_NONE;
}
ble_error_t GenericSecurityManager::slave_security_request(connection_handle_t connection) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
AuthenticationMask link_authentication(_default_authentication);
link_authentication.set_mitm(cb->mitm_requested);
return _pal.slave_security_request(connection, link_authentication);
}
ble_error_t GenericSecurityManager::enable_encryption(connection_handle_t connection) {
if (!_db) return BLE_ERROR_INITIALIZATION_INCOMPLETE;
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return BLE_ERROR_INVALID_PARAM;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return BLE_ERROR_INVALID_PARAM;
}
if (cb->is_master) {
if (flags->ltk_stored) {
_db->get_entry_peer_keys(
mbed::callback(this, &GenericSecurityManager::enable_encryption_cb),
cb->db_entry
);
return BLE_ERROR_NONE;
} else {
return requestPairing(connection);
}
} else {
return slave_security_request(connection);
}
}
void GenericSecurityManager::enable_encryption_cb(
SecurityDb::entry_handle_t db_entry,
const SecurityEntryKeys_t* entryKeys
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(db_entry);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
if (entryKeys) {
if (flags->secure_connections_paired) {
_pal.enable_encryption(cb->connection, entryKeys->ltk, flags->ltk_mitm_protected);
} else {
_pal.enable_encryption(cb->connection, entryKeys->ltk, entryKeys->rand, entryKeys->ediv, flags->ltk_mitm_protected);
}
}
}
void GenericSecurityManager::set_ltk_cb(
SecurityDb::entry_handle_t db_entry,
const SecurityEntryKeys_t* entryKeys
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(db_entry);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
if (entryKeys) {
_pal.set_ltk(
cb->connection,
entryKeys->ltk,
flags->ltk_mitm_protected,
flags->secure_connections_paired
);
} else {
_pal.set_ltk_not_found(cb->connection);
}
}
void GenericSecurityManager::set_peer_csrk_cb(
SecurityDb::entry_handle_t db_entry,
const SecurityEntrySigning_t* signing
) {
ControlBlock_t *cb = get_control_block(db_entry);
if (!cb || !signing) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
_pal.set_peer_csrk(
cb->connection,
signing->csrk,
flags->csrk_mitm_protected,
signing->counter
);
}
void GenericSecurityManager::return_csrk_cb(
SecurityDb::entry_handle_t db_entry,
const SecurityEntrySigning_t *signing
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(db_entry);
if (!cb || !signing) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
eventHandler->signingKey(
cb->connection,
&signing->csrk,
flags->csrk_mitm_protected
);
}
void GenericSecurityManager::update_oob_presence(connection_handle_t connection) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
/* if we support secure connection we only care about secure connections oob data */
if (_default_authentication.get_secure_connections()) {
cb->oob_present = (flags->peer_address == _oob_peer_address);
} else {
/* otherwise for legacy pairing we first set the oob based on set preference */
cb->oob_present = cb->attempt_oob;
/* and also turn it on if we have oob data for legacy pairing */
if (flags->peer_address == _oob_temporary_key_creator_address
|| cb->local_address == _oob_temporary_key_creator_address) {
cb->oob_present = true;
}
}
}
void GenericSecurityManager::set_mitm_performed(connection_handle_t connection, bool enable) {
ControlBlock_t *cb = get_control_block(connection);
if (cb) {
cb->mitm_performed = enable;
/* whenever we reset mitm performed we also reset pending requests
* as this happens whenever a new pairing attempt happens */
if (!enable) {
cb->legacy_pairing_oob_request_pending = false;
}
}
}
void GenericSecurityManager::on_connected(
connection_handle_t connection,
Gap::Role_t role,
peer_address_type_t peer_address_type,
const BLEProtocol::AddressBytes_t peer_address,
BLEProtocol::AddressType_t local_address_type,
const BLEProtocol::AddressBytes_t local_address,
const Gap::ConnectionParams_t *connection_params
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = acquire_control_block(connection);
if (!cb) {
return;
}
// setup the control block
cb->local_address = local_address;
cb->is_master = (role == Gap::CENTRAL);
// get the associated db handle and the distribution flags if any
cb->db_entry = _db->open_entry(peer_address_type, peer_address);
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
flags->peer_address = peer_address;
flags->peer_address_is_public =
(peer_address_type == peer_address_type_t::PUBLIC) ||
(peer_address_type == peer_address_type_t::PUBLIC_IDENTITY);
const bool signing = cb->signing_override_default ?
cb->signing_requested :
_default_key_distribution.get_signing();
if (signing && flags->csrk_stored) {
_db->get_entry_peer_csrk(
mbed::callback(this, &GenericSecurityManager::set_peer_csrk_cb),
cb->db_entry
);
}
}
void GenericSecurityManager::on_disconnected(
connection_handle_t connection,
Gap::DisconnectionReason_t reason
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
_pal.remove_peer_csrk(connection);
_db->close_entry(cb->db_entry);
release_control_block(cb);
}
void GenericSecurityManager::on_security_entry_retrieved(
SecurityDb::entry_handle_t entry,
const SecurityEntryIdentity_t* identity
) {
if (!identity) {
return;
}
typedef advertising_peer_address_type_t address_type_t;
_pal.add_device_to_resolving_list(
identity->identity_address_is_public ?
address_type_t::PUBLIC_ADDRESS :
address_type_t::RANDOM_ADDRESS,
identity->identity_address,
identity->irk
);
}
void GenericSecurityManager::on_identity_list_retrieved(
ble::ArrayView<SecurityEntryIdentity_t>& identity_list,
size_t count
) {
typedef advertising_peer_address_type_t address_type_t;
_pal.clear_resolving_list();
for (size_t i = 0; i < count; ++i) {
_pal.add_device_to_resolving_list(
identity_list[i].identity_address_is_public ?
address_type_t::PUBLIC_ADDRESS :
address_type_t::RANDOM_ADDRESS,
identity_list[i].identity_address,
identity_list[i].irk
);
}
delete [] identity_list.data();
}
/* Implements ble::pal::SecurityManagerEventHandler */
////////////////////////////////////////////////////////////////////////////
// Pairing
//
void GenericSecurityManager::on_pairing_request(
connection_handle_t connection,
bool use_oob,
AuthenticationMask authentication,
KeyDistribution initiator_dist,
KeyDistribution responder_dist
) {
/* cancel pairing if secure connection paring is not possible */
if (!_legacy_pairing_allowed && !authentication.get_secure_connections()) {
cancelPairingRequest(connection);
return;
}
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
cb->set_initiator_key_distribution(initiator_dist);
cb->set_responder_key_distribution(responder_dist);
cb->mitm_performed = false;
if (_pairing_authorisation_required) {
eventHandler->pairingRequest(connection);
} else {
acceptPairingRequest(connection);
}
}
void GenericSecurityManager::on_pairing_error(
connection_handle_t connection,
pairing_failure_t error
) {
set_mitm_performed(connection, false);
eventHandler->pairingResult(
connection,
(SecurityManager::SecurityCompletionStatus_t)(error.value() | 0x80)
);
/* if this pairing was triggered by a failed encryption attempt
* inform the application of the encryption failure */
ControlBlock_t *cb = get_control_block(connection);
if (cb && cb->encryption_requested && cb->encryption_failed) {
eventHandler->linkEncryptionResult(
connection,
link_encryption_t::NOT_ENCRYPTED
);
}
}
void GenericSecurityManager::on_pairing_timed_out(connection_handle_t connection) {
set_mitm_performed(connection, false);
eventHandler->pairingResult(
connection,
SecurityManager::SEC_STATUS_TIMEOUT
);
}
void GenericSecurityManager::on_pairing_completed(connection_handle_t connection) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (cb) {
_db->get_entry_identity(
mbed::callback(this, &GenericSecurityManager::on_security_entry_retrieved),
cb->db_entry
);
}
eventHandler->pairingResult(
connection,
SecurityManager::SEC_STATUS_SUCCESS
);
}
////////////////////////////////////////////////////////////////////////////
// Security
//
void GenericSecurityManager::on_valid_mic_timeout(connection_handle_t connection) {
(void)connection;
}
void GenericSecurityManager::on_signed_write_received(
connection_handle_t connection,
sign_count_t sign_counter
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
_db->set_entry_peer_sign_counter(cb->db_entry, sign_counter);
}
void GenericSecurityManager::on_signed_write_verification_failure(
connection_handle_t connection
) {
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
const bool signing = cb->signing_override_default ?
cb->signing_requested :
_default_key_distribution.get_signing();
if (signing) {
cb->csrk_failures++;
if (cb->csrk_failures == 3) {
cb->csrk_failures = 0;
if (cb->is_master) {
requestPairing(connection);
} else {
slave_security_request(connection);
}
}
}
}
void GenericSecurityManager::on_signed_write() {
MBED_ASSERT(_db);
_db->set_local_sign_counter(_db->get_local_sign_counter() + 1);
}
void GenericSecurityManager::on_slave_security_request(
connection_handle_t connection,
AuthenticationMask authentication
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
bool pairing_required = false;
if (authentication.get_secure_connections() && !flags->secure_connections_paired
&& _default_authentication.get_secure_connections()) {
pairing_required = true;
}
if (authentication.get_mitm() && !flags->ltk_mitm_protected) {
pairing_required = true;
cb->mitm_requested = true;
}
if (pairing_required) {
requestPairing(connection);
} else if (!cb->encryption_requested) {
/* this will refresh keys if encryption is already present */
enable_encryption(connection);
}
}
////////////////////////////////////////////////////////////////////////////
// Encryption
//
void GenericSecurityManager::on_link_encryption_result(
connection_handle_t connection,
link_encryption_t result
) {
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
if (result == link_encryption_t::ENCRYPTED) {
cb->encryption_requested = false;
cb->encryption_failed = false;
cb->encrypted = true;
} else if (
result == link_encryption_t::ENCRYPTED_WITH_MITM ||
result == link_encryption_t::ENCRYPTED_WITH_SC_AND_MITM
) {
cb->encryption_requested = false;
cb->encryption_failed = false;
cb->authenticated = true;
cb->encrypted = true;
} else if (result == link_encryption_t::NOT_ENCRYPTED
&& cb->encryption_requested
&& !cb->encryption_failed) {
/* if we failed encryption for the first time
* retry repairing in case slave lost LTK */
requestPairing(cb->connection);
cb->encryption_failed = true;
/* don't return an event yet since we are retrying */
return;
}
eventHandler->linkEncryptionResult(connection, result);
}
void GenericSecurityManager::on_link_encryption_request_timed_out(
connection_handle_t connection
) {
eventHandler->linkEncryptionResult(
connection,
link_encryption_t::NOT_ENCRYPTED
);
}
////////////////////////////////////////////////////////////////////////////
// MITM
//
void GenericSecurityManager::on_passkey_display(
connection_handle_t connection,
passkey_num_t passkey
) {
set_mitm_performed(connection);
eventHandler->passkeyDisplay(connection, PasskeyAscii(passkey).value());
}
void GenericSecurityManager::on_keypress_notification(
connection_handle_t connection,
SecurityManager::Keypress_t keypress
) {
set_mitm_performed(connection);
eventHandler->keypressNotification(connection, keypress);
}
void GenericSecurityManager::on_passkey_request(connection_handle_t connection) {
set_mitm_performed(connection);
eventHandler->passkeyRequest(connection);
}
void GenericSecurityManager::on_confirmation_request(connection_handle_t connection) {
set_mitm_performed(connection);
eventHandler->confirmationRequest(connection);
}
void GenericSecurityManager::on_secure_connections_oob_request(connection_handle_t connection) {
set_mitm_performed(connection);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
if (flags->peer_address == _oob_peer_address) {
_pal.secure_connections_oob_request_reply(connection, _oob_local_random, _oob_peer_random, _oob_peer_confirm);
/* do not re-use peer OOB */
set_all_zeros(_oob_peer_address);
} else {
_pal.cancel_pairing(connection, pairing_failure_t::OOB_NOT_AVAILABLE);
}
}
void GenericSecurityManager::on_legacy_pairing_oob_request(connection_handle_t connection) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
if (flags->peer_address == _oob_temporary_key_creator_address
|| cb->local_address == _oob_temporary_key_creator_address) {
set_mitm_performed(connection);
_pal.legacy_pairing_oob_request_reply(connection, _oob_temporary_key);
/* do not re-use peer OOB */
if (flags->peer_address == _oob_temporary_key_creator_address) {
set_all_zeros(_oob_temporary_key_creator_address);
}
} else if (!cb->legacy_pairing_oob_request_pending) {
cb->legacy_pairing_oob_request_pending = true;
eventHandler->legacyPairingOobRequest(connection);
}
}
void GenericSecurityManager::on_secure_connections_oob_generated(
const oob_lesc_value_t &random,
const oob_confirm_t &confirm
) {
eventHandler->oobGenerated(&_oob_local_address, &random, &confirm);
_oob_local_random = random;
}
////////////////////////////////////////////////////////////////////////////
// Keys
//
void GenericSecurityManager::on_secure_connections_ltk_generated(
connection_handle_t connection,
const ltk_t &ltk
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
flags->ltk_mitm_protected = cb->mitm_performed;
flags->secure_connections_paired = true;
_db->set_entry_peer_ltk(cb->db_entry, ltk);
}
void GenericSecurityManager::on_keys_distributed_ltk(
connection_handle_t connection,
const ltk_t &ltk
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
flags->ltk_mitm_protected = cb->mitm_performed;
_db->set_entry_peer_ltk(cb->db_entry, ltk);
}
void GenericSecurityManager::on_keys_distributed_ediv_rand(
connection_handle_t connection,
const ediv_t &ediv,
const rand_t &rand
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
_db->set_entry_peer_ediv_rand(cb->db_entry, ediv, rand);
}
void GenericSecurityManager::on_keys_distributed_local_ltk(
connection_handle_t connection,
const ltk_t &ltk
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
_db->set_entry_local_ltk(cb->db_entry, ltk);
}
void GenericSecurityManager::on_keys_distributed_local_ediv_rand(
connection_handle_t connection,
const ediv_t &ediv,
const rand_t &rand
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
_db->set_entry_local_ediv_rand(cb->db_entry, ediv, rand);
}
void GenericSecurityManager::on_keys_distributed_irk(
connection_handle_t connection,
const irk_t &irk
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
_db->set_entry_peer_irk(cb->db_entry, irk);
}
void GenericSecurityManager::on_keys_distributed_bdaddr(
connection_handle_t connection,
advertising_peer_address_type_t peer_address_type,
const address_t &peer_identity_address
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
_db->set_entry_peer_bdaddr(
cb->db_entry,
(peer_address_type == advertising_peer_address_type_t::PUBLIC_ADDRESS),
peer_identity_address
);
}
void GenericSecurityManager::on_keys_distributed_csrk(
connection_handle_t connection,
const csrk_t &csrk
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
flags->csrk_mitm_protected = cb->mitm_performed;
_db->set_entry_peer_csrk(cb->db_entry, csrk);
eventHandler->signingKey(
connection,
&csrk,
flags->csrk_mitm_protected
);
}
void GenericSecurityManager::on_ltk_request(
connection_handle_t connection,
const ediv_t &ediv,
const rand_t &rand
) {
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (!flags) {
return;
}
_db->get_entry_local_keys(
mbed::callback(this, &GenericSecurityManager::set_ltk_cb),
cb->db_entry,
ediv,
rand
);
}
/* control blocks list management */
GenericSecurityManager::ControlBlock_t::ControlBlock_t() :
connection(0),
db_entry(0),
local_address(),
connected(false),
authenticated(false),
is_master(false),
encryption_requested(false),
encryption_failed(false),
encrypted(false),
signing_requested(false),
signing_override_default(false),
mitm_requested(false),
mitm_performed(false),
attempt_oob(false),
oob_mitm_protection(false),
oob_present(false),
legacy_pairing_oob_request_pending(false),
csrk_failures(0) { }
void GenericSecurityManager::on_ltk_request(connection_handle_t connection)
{
MBED_ASSERT(_db);
ControlBlock_t *cb = get_control_block(connection);
if (!cb) {
return;
}
_db->get_entry_local_keys(
mbed::callback(this, &GenericSecurityManager::set_ltk_cb),
cb->db_entry
);
}
GenericSecurityManager::ControlBlock_t*
GenericSecurityManager::acquire_control_block(connection_handle_t connection)
{
/* grab the first disconnected slot*/
for (size_t i = 0; i < MAX_CONTROL_BLOCKS; i++) {
if (!_control_blocks[i].connected) {
ControlBlock_t* cb = &_control_blocks[i];
cb->connected = true;
cb->connection = connection;
return cb;
}
}
return NULL;
}
GenericSecurityManager::ControlBlock_t* GenericSecurityManager::get_control_block(
connection_handle_t connection
) {
for (size_t i = 0; i < MAX_CONTROL_BLOCKS; i++) {
if (!_control_blocks[i].connected) {
continue;
} else if (connection == _control_blocks[i].connection) {
return &_control_blocks[i];
}
}
return NULL;
}
GenericSecurityManager::ControlBlock_t* GenericSecurityManager::get_control_block(
const address_t &peer_address
) {
MBED_ASSERT(_db);
for (size_t i = 0; i < MAX_CONTROL_BLOCKS; i++) {
ControlBlock_t *cb = &_control_blocks[i];
if (cb->connected) {
SecurityDistributionFlags_t* flags = _db->get_distribution_flags(cb->db_entry);
if (flags && (flags->peer_address == peer_address)) {
return cb;
}
}
}
return NULL;
}
GenericSecurityManager::ControlBlock_t* GenericSecurityManager::get_control_block(
SecurityDb::entry_handle_t db_entry
) {
for (size_t i = 0; i < MAX_CONTROL_BLOCKS; i++) {
if (!_control_blocks[i].connected) {
continue;
} else if (db_entry == _control_blocks[i].db_entry) {
return &_control_blocks[i];
}
}
return NULL;
}
void GenericSecurityManager::release_control_block(ControlBlock_t* cb)
{
*cb = ControlBlock_t();
}
} /* namespace generic */
} /* namespace ble */
Reference in New Issue View Git Blame Copy Permalink