1# Change Log 2All notable changes to this project will be documented in this file. 3 4The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) 5and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html). 6 7--- 8 9## [Unreleased] 10 11### Fixed 12### Added 13### Changed 14 15## Changes October 2020 16 17### Fixed 18- AVRCP/AVCTP: report AVRCP 1.6 and AVCTP 1.4 in SDP record 19- AVDTP Initiator: avoid use of remote seid for stream endpoint lookup, fixes issue with two connected devices 20- AVDTP Source: buffer for SBC media codec information got discarded, leading to invalid Set Configuration command in second connection 21- SM: only trigger Cross-Transport Key Derivation (CTKD) when bonding is enabled 22- SM: set LinkKey flag to request CTKD if enabled 23- SM: store CTKD key with Public Identity Address 24- SM: only allow CTKD to overwrite existing link key if derived key has same or higher authentication 25- HFP HF: fix response to AG Codec Selection while waiting for OK of parallel command 26- HCI: fix reject of LE remote connection param request via HCI 27 28### Added 29- GAP: add `gap_get_link_key_for_bd_addr` 30- GAP: add `gap_bonded` to check if bonding information is available for active connection 31- SM: support h7 for CTKD 32 33### Changed 34- SM: Cross-Transport Key Derivation requires `ENABLE_CROSS_TRANSPORT_KEY_DERIVATION` now 35 36## Changes September 2020 37 38### Fixed 39- HFP: fix parsing of ranges e.g. in +CIND responses 40- AVDTP, AVRCP: fix bugs due to transaction id overrun 41- A2DP Source: fix issues with stream configuration by sink 42- hci_dump: fix tv_us calculation for non-posix / embedded systems with binary output 43 44### Added 45- `btstack_ring_buffer`: add `btstack_ring_buffer_reset` to reset it to initial state/empty 46- GAP: Support for address resolution of resolvable private addresses by Controller with `ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION` 47 48### Changed 49- AVDTP, AVRCP, HSP: schedule SDP query, avoids avoids 'command disallowed' if SDP client is busy 50- HSP, HFP: allow to configure usable SCO packet types 51- cc256x: update CC256xC init script to v1.4 52- A2DP Source: use Get All Capabilities if supported by remote get Delay Reporting capability 53 54## Changes August 2020 55 56### Fixed 57- ESP32: fix authentication for incoming Secure Connections 58- AVDTP: Fix forwarding of Delay reports 59- STM32-F4Discovery: fix pan_lwip_http_server by increasing HCI_ACL_PAYLOAD_SIZE 60- tool/create_packet_log: basic support for 16-bit Unicode log files from Windows 61 62### Added 63- `btstack_run_loop_base`: added `btstack_run_loop_base_dump_timer` 64- GAP: request role change for classic connection via `gap_request_role` 65- GAP: LE Whitelist API with `gap_le_whitelist_x` with x = add, remove, clear and new `gap_connect_with_whitelist` 66- SDP Client: add sdp_client_register_query_callback() allows to register query request instead of polling sdp_client_ready() 67- BNEP lwIP: add `bnep_lwip_connect` to establish BNEP connection and manage lwIP network interface 68- New `btstack_linked_queue` utility, a linked list-based queue with first-in-first-out semantics and constant time enqueue/dequeue operations 69- btstack_tlv_posix: add `btstack_tlv_posix_deinit` 70- New `btpclient` for use with [auto-pts project](https://github.com/intel/auto-pts) 71 72### Changed 73- GAP: treat AES-CCM encrypted connection as mutually authenticated (BIAS) 74- GAP: 'gap_auto_connect_x' API deprecated. Please direclty manage LE Whitelist with `gap_le_whitelist_*` functions and call `gap_connect_with_whitelist` instead 75- example/hid_host_demo: try to become master for incoming connections 76- btstack_run_loop: use btstack_assert instead of local while(true) 77- att_db_util: allow to reset att_db via `att_db_util_init` 78 79## Changes July 2020 80 81### Fixed 82- AVDTP: fix invalid response for Get Capabilities request if Delay Reporting was supported 83- AVDTP: handle concurrent signaling establishment with reject and retry 84 85### Added 86- example/hid_host_demo: support reconnect from HID device 87- Crypto: support software AES128 for AES-CCM operations 88- AVRCP: introduced AVRCP_FEATURE_MASK_* as alternative to avrcp_controller_supported_feature_t and avrcp_target_supported_feature_t enums 89- btstack_audio: add set_volume() to sink and set_gain() to source interfaces, minimal volume control for portaudio playback 90- AVDTP: renamed definition of supported features from AVDTP_SOURCE_SF_ and AVDTP_SINK_SF_ to AVDTP_SOURCE_FEATURE_MASK_ and AVDTP_SINK_FEATURE_MASK_ respectively 91- GAP: Provide gap_get_role to query master/slave role for HCI connection handle 92- GAP: Provide gap_pin_code_response_binary to use binary data as PIN, e.g. for pairing with Nintendo Wii Remote 93 94### Changed 95- GAP: set minimum required encryption key size for Classic connections back from 16 to 7, matching the Core spec 96 97 98## Changes June 2020 99 100### Fixed 101- HFP: Fix parsing of empty fields, e.g. phone number in +CLCC and other AT commands 102- SM: Fix validation of confirm value for secure connection Passkey entry 103- AVRCP: handle concurrent signaling establishment with reject and retry 104 105### Added 106- GAP: Detect Secure Connection -> Legacy Connection Downgrade Attack by remote features and actual encryption type (BIAS) 107- GAP: Mutual authentication: request authentication after Classic connection got encrypted (BIAS) 108- Windows port for Dialog DA14585 connected via serial port 109 110## Changes 111- CVSD PLC: treat zero frames as good and allow to mark data as bad, e.g. if reported by Controller as erroneous 112 113## Changes May 2020 114 115### Fixed 116- hfp_hf, hsp_hs: use eSCO params in accept sco connection only for incoming eSCO connections 117- pbap_client: fix PBAP UUID len on connect message 118- SM: fix secure connection pairing as peripheral when local user confirmation happens after remote one 119- A2DP Source: only connect to remote sink stream endpoints 120- btstack_hal_flash_memory: fix write of 0xff bytes to simulated flash 121- hsp_hs: fix disconnect if audio not connected 122- hsp_ag: fix accept incoming connection 123 124### Added 125- example/le_mitm: MITM implementation that forwards ATT PDUs and allows for pairing 126- GAP: gap_set_security_level sets required security level for incoming and outgoing connections 127- cc256x: allow to specify power vector for each modulation type 128- FreeRTOS: btstack_run_loop_freertos_trigger_exit allows to request run loop exit 129- SM: support LE Secure Connections Only mode with sm_set_secure_connections_only_mode 130- GAP: enable BR/EDR Secure Connections if supported, add gap_secure_connections_enable 131 132### Changed 133- L2CAP ERTM: send extended features request only once per HCI connection 134 135 136## Changes April 2020 137 138### Fixed 139- hog_mouse_demo/hog_keyboard_demo: handle set protocol mode = boot protocol mode 140- HCI: only update BD_ADDR placeholder in shortened and complete name in EIR data, limit device name to 240/248 bytes 141 142### Added 143- GAP: gap_set_allow_role_switch allows to prevent role switch in outgoing classic ACL connections 144- example: hog_boot_host_demo implements an HID-over-GATT Boot Host that supports keyboard and mouse 145- HCI: add ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS that forces fragmentation of ACL-LE packets to fit into over-the-air packet 146 147### Changed 148- Broadcom/Cypress: wait 300 ms after PatchRAM update in hci.c to assert Controller is ready 149- esp32: provide esp-idf/component/btstack/btstack_port_esp32.c and only minimal app_main in template/main/main.c 150- att_db: skip att_read_callback for ATT Read Blob Request if offset == value_len 151 152 153## Changes March 2020 154 155### Fixed 156- GAP: fixed gap_set_scan_parameters() if issued right before gap_start_scan() 157- HCI: only send HCI Read Local Encryption Key Size if supported by Controller 158 159### Added 160- GATT Client: allow to register for any notification/indication and/or any connection 161- HCI: added hci_read_inquiry_scan_activity and hci_write_inquiry_scan_activity commands 162- chipset: assert hci packet buffers are suitable for firmware upload or patches (atwilc3000,bcm,cc256x,intel) 163- btstack_util: added btstack_replace_bd_addr_placeholder 164 165### Changed 166- AVRCP Target: volume in avrcp_target_volume_changed is reported as current value in interim response to register for volume change notifications 167- SDP Client: query attributes 0x0000..0xffff instead of 0x0001..0xffff to match other stacks / improve compatibility with bad sdp server implementations 168 169 170## Changes Februar 2020 171 172### Fixed 173- AVRCP Target: fix reporting of PLAYBACK_STATUS_CHANGED 174- HCI: handle reconnect request for Classic and LE connections triggered by packet handler for Disconnection Complete Event 175 176### Changed 177- hid_host_mode: allow sniff mode 178 179### Added 180- port/qt-usb and port/qt-h4: integrate BTstack Qt run loop for Unix- and Win32-based Qt application connected to Bluetooth module via H4 over serial port or USB 181 182 183## Changes January 2020 184 185### Fixed 186- L2CAP ERTM: avoid read-after-free on decline of incoming connection 187- GATT Client: set uuid16 to zero when deserializing uuid128 services, characteristics, and descriptors 188- att_db_util: fix realloc of att db buffer for large attributes 189- btstack_tlv_posix: only keep last value in memory, fix delete operation 190- l2cap_signaling: use packet boundary flags 0x00 for LE signaling packets (ignoring hci_non_flushable_packet_boundary_flag_supported()) 191 192### Added 193- att_db_util: provide GATT Database Hash via att_db_util_hash_calc 194- GATT Compiler: provide GATT Database Hash via GATT_DATABASE_HASH Characteristic 195- ATT Server: validate request pdu length 196 197### Changed 198- Crypto: update AES-CMAC implementation to access all message bytes sequentially 199 200 201## Changes December 2019 202 203### Fixed 204- example/pan_lwip_http_server: use Network Access Point, CoD 205- sm: emit pairing complete in master role when no keys are distributed / bonding disabled 206 207### Added 208 209### Changed 210- Updated CC256x initscript: CC256xC v1.3 211- ESP32: add CMake project files 212 213 214## Changes November 2019 215 216### Fixed 217- AVDTP Source: return correct `avdtp_cid` and `local_seid` in `AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW` 218- L2CAP: send LE Data Channel SDUs round robin with other data 219- L2CAP ERTM: send ERTM I-frames round robin with other data 220 221### Added 222- ATT Server: return error if request to send now for Notification or Indication already registered 223- Linked List: return if item was added for `btstack_linked_list_add[_tail]` 224- btstack_run_loop_remove: return bool true if timer/data source was removed 225- segger-rtt: allow to configure with `SEGGER_RTT_PACKETLOG_*` directives, update to v6.54 226- GAP: support setting Link Supervision Timetout for outgoing Classic connections using `gap_set_link_supervision_timeout` 227- lwip: add download test files to http server demo 228 229### Changed 230- Linked List: return bool true if item was removed 231 232 233## Changes October 2019 234 235### Fixed 236 237### Added 238- `btstack_bool.h`: provide boolean type 'bool' via `<stdbool.h>` or as backport 239- provide `btstack_assert(condition)` 240- H4 Transport: avoid calling `hci_transport_h4_trigger_next_read` when transport is closed 241 242### Changed 243- libusb and posix ports: store bonding information in TLV 244 245 246## Changes September 2019 247 248### Fixed 249- L2CAP ERTM: assert that packet can be stored in fragment buffers in ertm 250- L2CAP ERTM: reject incoming connection if ERTM is configured as mandatory but not supported by remote 251- GATT Client: allow Write Without Response independent of other requests 252 253### Added 254- GAP: allow to reject GAP classic connection via gap_register_classic_connection_filter 255- GAP: support reading RSSI for Classic+LE using gap_read_rssi. Emits `GAP_EVENT_RSSI_MEASUREMENT` 256 257### Changed 258- Bluetooth and BTstack Error Codes and Events: collect status codes in bluetooth.h and events in btstack_defines.h 259- bluetooth.h: extract internal defintitions to respective protocol layers 260- Updated CC256x initscripts (CC256xB v1.8, CC256xC v1.2, CC256xC v1.2) 261 262 263## Changes August 2019 264 265### Fixed 266- POSIX, WICED, Windows, FreeRTOS run loops: handle time_ms overrun after 49 days 267- RFCOMM: accept incoming L2CAP connection in Basic mode if ERTM is enabled but not requested for this connection 268- RFCOMM: limit RFCOMM MTU by local L2CAP MTU for outgoing connections (only revelvant for ERTM) 269- L2CAP ERTM: stop timers on disconnect 270- L2CAP ERTM: fix sending of segmented SDUs 271- L2CAP ERTM: handle unsupported Information Response 272- SM: generate local nonce for confirm value in JW+NC+PK in Secure Connections Responder role 273 274### Added 275- `btstack_run_loop_base`: portable implementation of timer and data source management as base for platform specific implementations 276 277## Changed 278- FreeRTOS: use xQueueCreateStatic (static variant of xQueueCreate) if available for static memory-only setups 279- L2CAP ERTM: handle invalid Information Response (assume no extended features supported) 280- POSIX: use monotonic clock as timebase if available 281- HCI Transport H4/H5/EM9304 SPI: ignore block read/sent from UART driver when closed 282- HCI: Read Encryption Key Size after encryption was enabled 283- Errata 11838: 284 - GAP: gap_set_required_encryption_key_size allows to set the required key size, default = 16 (max) 285 - GAP: validate encryption key size to emit GAP Security Levels 286 287## Changes July 2019 288 289### Fixed 290- SM: Fixed regression introduced in f3582630 291- L2CAP: avoid reading l2cap signaling command len out of bounds 292- HCI Transport H4/H5/EM9304 SPI: fix payload size checks (also for 8/16-bit platforms) 293 294### Changed 295- SM: Start encryption upon receiving slave securiy request if bonded 296- hci: use 2 as HCI_INCOMING_PRE_BUFFER_SIZE in LE-only configuration for GATT Client 297 298--- 299 300## Changes June 2019 301 302### Changed 303- FreeRTOS: use freertos/.. prefix to include FreeRTOS headers if HAVE_FREERTOS_INCLUDE_PREFIX is defined 304- BNEP: add Connection Handle to BNEP_EVENT_CHANNEL_OPENED 305- Examples: renamed le_counter to gatt_counter and le_streamer to le_streamer_server to indicate suppport for GATT over BR/EDR 306 307### Fixed 308- BNEP: Bluetooth address is stored in little-endian format for all BNEP_EVENT_* 309- libusb: avoid use-after-free for SCO packets on disconnect 310 311### Added 312- example: pan_lwip_http_server using lwIP as network stack to implement PAN NAP service 313- platform/lwip/bnep_lwip.c: BNEP lwIP adapter that forwards packets between BNEP service and lwIP 314- ENABLE_GATT_OVER_CLASSIC enables support for GATT over BR/EDR in att_server 315 316--- 317 318## Changes May 2019 319 320### Changed 321- ESP32: Configure SCO over HCI after power up 322- btstack_tlv_flash_bank: support targets where a value cannot be overwritten with zero. When ENABLE_TLV_FLASH_EXPLICIT_DELETE_FIELD 323 is defined, an explicit delete field is used to indicate an invalid entry. 324 325### Fixed 326- SM: Avoid potential use-after-free on immediate disconnect (lookup connection via con handle instead of storing pointer) 327 328### Added 329- gatt_client: emit query complete event for signed write operation 330- hci_transport_h4: add workaround for flow control bug in CYW2070x, enable with ENABLE_CYPRESS_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND 331 332--- 333 334## Changes April 2019 335 336### Changed 337- ESP32: use micro-ecc from 3rd-party as esp-idf removed it in their 3.3 release 338 339### Fixed 340- hci: pad LE Scan response with zeroes 341- SM: store local CSRK 342- ATT DB: call write callback for validated signed writes 343- ATT Server: abort signed write validation on incoming new request 344- Bluetooth SIG web scraping tools updated 345- libusb: compiles for FreeBSD 346 347### Added 348 349--- 350 351## Changes March 2019 352 353### Changed 354- use Makefile for stm32-f4discovery-cc256x port 355- le_device_db: add secure_connection argument to le_device_db_encryption_set and le_device_db_encryption_get 356 357### Fixed 358- SM: Use provided authentication requirements in slave security request 359 360### Added 361- port/stm32-f4discovery-cc256x: add support for built-in MEMS microphone 362- SM: Track if connection encryption is based on LE Secure Connection pairing 363- ATT DB: Validate if connection encrypted is based on SC if requested 364- att_db_util: support ATT_SECURITY_AUTHENTICATED_SC permission flag 365- GATT Compiler: support READ_AUTHENTICATED and WRITE_AUTHENTICATED permsission flags 366- ESP32: erase nvs flash is newer nvs version found 367- libusb: add support for nRF52840-PCA10056 running Zephyr hci_usb example 368- port/stm32-l073rz-nucleo-em9304 for Nucleo L073RZ with EM9304 DVK, replaces port/stm32-l053r8-nucleo-em9304 369 370## Changes February 2019 371 372### Changed 373- example/a2dp_sink_demo: use linear resampling to fix sample rate drift 374- btstack_audio: split interface into sink and source 375 376### Fixed 377- Crypto: fix lockup when stack is shutdown while waiting for result of HCI Command, e.g. LE Read Local P256 Public Key 378- SM: Avoid SM_EVENT_PAIRING_COMPLETE with ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION after successful pairing in responder role 379 380### Added 381- example/a2dp_sink_demo: add target role, support volume control on both devices 382- example/audio_duplex: playback audio audio source on audio sink (test audio path) 383- btstack_audio_embedded: implement audio source path 384 385--- 386 387## Changes January 2019 388 389### Changed 390- L2CAP: provide channel mode (basic/ertm) and fcs option in L2CAP_EVENT_CHANNEL_OPENED 391- RFCOMM: support L2CAP ERTM. Callbacks passed to rfcomm_enable_l2cap_ertm() are used to manage ERTM buffers 392 393### Added 394- L2CAP: emit L2CAP_EVENT_ERTM_BUFFER_RELEASED if ERTM buffer not needed/used anymore 395- L2CAP: add fcs_option to ERTM config l2cap_ertm_config_t 396- HCI: validate advertisement data length field when generating GAP_EVENT_ADVERTISING_REPORT 397- ad_parser: validate data element length fields in ad_iterator_has_more 398- Raspberry Pi 3 A+/B+ port in port/raspi, starts without power cycle 399 400### Fixed 401- HCI: release outgoing buffer on disconnect if waiting to send another ACL fragment 402- POSIX: use correct baudrate enums for baud rates higher than 921600 (Linux) 403- Crypto: directly process queued crypto operation on HCI result 404 405--- 406 407## Changes December 2018 408 409### Added 410- SM: generate and store ER / IR keys in TLV, unless manually set by application 411- hci_dump: support PacketLogger or BlueZ format output via SEGGER RTT Channel 1 Up 412 413### Fixed 414- SM: fix internal buffer overrun during random address generation 415 416## Changes November 2018 417 418### Added 419- GAP: gap_le_connection_interval provides connection interval for conn handle 420- Nordic SPP Service Server: GATT service that emulates a serial port over BLE based on Nordic Semiconductor documentation. 421- uBlox SPP Service Server: GATT service that emulates a serial port over BLE based on uBlox documentation. 422- SM: ENABLE_LE_CENTRAL_AUTO_ENCRYPTION triggers automatic encryption on connect to bonded devices 423- SM: generate and store ER / IR keys in TLV, unless manually set by application 424 425### Fixed 426- SM: prevent random address updates if gap_random_address_set was used 427- SM: fix internal buffer overrun that can cause storing of bonding information to fail 428- SM: ignore Slave Security Request after sending own Pairing Request 429- L2CAP: fix use after free on disconnect if ERTM is enabled 430- HFP: Handle multiple commands/responses in single RFCOMM packet 431- Memory Pools: clear all buffers before use 432 433--- 434 435## Changes October 2018 436 437### Added 438- SDP Server: queue incoming connections when already connected instead of rejecting them 439- GAP: Support enter/exit sniff mode via gap_sniff_mode_enter/exit. gap_set_default_link_policy_settings is needed to enable sniff mode in general. 440- HIDS Device: GATT service that exposes HID reports intended for HID Devices, like keyboard and mouse. 441 442### Fixed 443- HCI: fix bug in gap_inquiry_stop that triggered additional GAP_EVENT_INQUIRY_COMPLETE instead of stopping the inquiry 444- L2CAP: fix issue with outgoing connection before read remote supported complete when other channels exist 445- L2CAP ERTM: allow SDU of szie MPS in first packet that contains L2CAP SDU Length 446- L2CAP ERTM: fix memory corruption triggered if local_mtu > mps 447- L2CAP ERTM: fix outgoing fragment management 448- HFP: decline incoming RFCOMM connection after outgoing connection was started 449- AVRCP: fix crash on disconnect of connection established by remote 450 451--- 452 453## Changes September 2018 454 455### Fixed 456- HCI: Error creating outgoing connection (e.g. Connection Limit Exceeded) now handled 457- L2CAP: Error creating outgoing connection (e.g. Connection Limit Exceeded) now handled 458- L2CAP: Evaluate 'can send now' on HCI Disconnect as ACL buffers in Bluetooth Controller have been used for the closed connection are freed implicitly 459- L2CAP: Check can send now before sending extended information requeste needed for ERTM mode 460- L2CAP: Use valid signaling identifier for L2CAP Connection Parameter Update Request 461- RFCOMM: Trigger l2cap request to send on rfcomm credits when client is waiting to sendtrigger l2cap request to send on rfcomm credits when client is waiting to send 462- RFCOMM: Avoid use-after-free on channel finalize 463- GATT Client: stop timer on disconnect - fixes use after free / crash 464 465### Added 466- A2DP Source: Support stream reconfiguration (a2dp_source_reconfigure_stream_sampling_frequency) 467- 3rd-party: yxml is used for PBAP vCard list parsing 468- cc256xC: new v1.1 init scripts 469 470--- 471 472## Changes August 2018 473 474### Added 475- PBAP: added pbap_get_phonebook_size() to get phonebook entry count 476 477### Fixed 478- GATT Server: Allow enable Notifications/Indication with Write Command. Fixes issue with some Android devices. 479- SM: fix pairing for Secure Connections with Bonding if remote sends additional keys 480- SM: drop LTK flag from Pairing Response for Secure Connections 481- L2CAP: fix emitted L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST 482 483## Changes June 2018 484 485### Added 486- btstack_audio.h: application level API for audio playback and recording 487- embedded/hal_audio.h: low-level API for audio playback and recording 488- HID Device: hid_device_connect(..) function 489- ESP32: implement hal_audio 490- DA14585: support for Dialog Semiconductor DA14585 LE-only controller 491- Raspberry Pi 3 + Raspberry Pi Zero W port in port/raspi 492 493### Changed 494- Errata 10734: 495 - SM: Generate new EC Public Keypair after each pairing 496 - SM: Abort failure with DHKEY_CHECK_FAILED if received public key is invalid (instead of unspecified error) 497- btstack.h: only include classic headers if ENABLE_CLASSIC is defined 498- windows: ignore virtual Bluetooth adapter provided by VMware 499- Replaced HCI_PACKET_BUFFER_SIZE with HCI_INCOMING_PACKET_BUFFER_SIZE and HCI_OUTGOING_PACKET_BUFFER_SIZE 500 501--- 502 503## Changes June 2018 504 505### Fixed 506- HFP: Fix Wide Band Speech bit in SDP record for both HF/AG. Missing bit prevents macOS from using mSBC 507- ATT Server: send ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE with status ATT_HANDLE_VALUE_INDICATION_DISCONNECT on disconnect 508- AVRCP Controller: fix parsing of now playing info 509 510### Changed 511- ATT Server: ATT_HANDLE_VALUE_INDICATION_DISCONNECT is delivered to service handler if registered 512 513### Added 514- ATT Server: packet handler field added to att_service_handler_t to receive: connect/disconnect, atu exchange, indication complete 515 516--- 517 518## Changes May 2018 519 520### Added 521- GAP: re-encrypt outgoing connection if bonded 522- ATT Server: wait until re-encryption is complete 523- GATT Client: wait until re-encryption is complete 524- ATT Server: added att_server_request_to_send_notification and att_server_request_to_send_indication 525- GATT Client: if ENABLE_GATT_CLIENT_PAIRING, GATT Client starts pairing and retry operation on security error 526 527### Changed 528- ATT Server: att_server_register_can_send_now_callback is deprecated, use att_server_request_to_send_notification/indication instead 529 530### Fixed 531- SM: Fix LE Secure Connection pairing in Central role 532- le_device_db_tlv: fix seq nr management 533- SM: improve le_device_db lookup and storing of IRK 534- GATT Server: fix lookup for Client Characteristic Configuration in services with multiple Characteristics 535- RFCOMM: emit channel closed on HCI/L2CAP disconnect after sending DISC while expecting UA 536 537--- 538 539## Changes April 2018 540 541### Added 542- Crypto: btstack_crypo.h provides cryptographic functions for random data generation, AES128, EEC, CBC-MAC (Mesh) 543- SM: support pairing using Out-of-Band (OOB) data with LE Secure Connections 544- Embedded: support btstack_stdin via SEGGER RTT 545 546### Changed 547- att_db_util: added security requirement arguments to characteristic creators 548- SM: use btstack_crypto for cryptographpic functions 549- GAP: security level for Classic protocols (asides SDP) raised to 2 (encryption) 550 551### Fixed 552- HFP: fix answer call command 553- HCI: fix buffer overrun in gap_inquiry_explode 554- SDP: free service record item on sdp_unregister_service 555 556## Changes March 2018 557 558### Added 559- GAP: allow to limit number of connections in LE Peripheral role with gap_set_max_number_peripheral_connections 560- ATT Server: support for delayed ATT read response, see example/att_delayed_read_response.c 561- ATT Server: allow to specify security requirements seperately for read/writes. .h files need to be regenerated 562 563### Fixed 564- RFCOMM: fix infinite loop on L2CAP connection error (regression from 4c3eeed1) 565- HSP HS: accept incomming SCO connection 566- SM: fix iteration over LE Device DB entries for bonding and address resolving 567- SM: store pairing information only if both devices have requested bonding 568 569--- 570 571## Changes February 2018 572 573### Added 574- GATT Client: gatt_client_request_can_write_without_response_event() causes GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE 575- SM: new event SM_EVENT_PAIRING_COMPLETE 576- GAP: support iteration over stored Classic link keys: gap_link_key_iterator_init, gap_link_key_iterator_get_next, gap_link_key_iterator_done 577- GAP: add gap_delete_all_link_keys 578 579### Changed 580- GATT Client: round robin for multiple connections 581- ATT Dispatch: round robin for ATT Server & GATT Client 582- L2CAP: round robin for all L2CAP channels (fixed and dynamic) 583- btstack_link_key_db: addition functions for link key iteration 584- GAP: LE scanning enabled not reset on HCI Reset -> can be enabled before HCI Power Up 585- CSR: set all keys in psram instead of default 586 587### Fixed 588- tc3556x: fix startup after baud rate change 589 590--- 591 592## Changes January 2018 593 594### Added 595- Port for Windows with Zephyr HCI Firmware connected via serial port 596- em9304: upload patch containers during HCI bootup 597- Makefile for STM32-F4Discovery port 598- support for console out via SEGGER RTT 599- LE Data Channels example in BTstack and [iOS example on GitHub](https://github.com/bluekitchen/CBL2CAPChannel-Demo) 600- LE Streamer Client can send as fast as possbile as well 601- L2CAP: option to limit ATT MTU via l2cap_set_max_le_mtu 602 603### Changed 604- HCI: allow to set hci_set_master_slave_policy (0: try to become master, 1: accept slave) 605- GAP: gap_set_connection_parameters includes scan interval and window params 606- GATT Client: GATT_EVENT_MTU indicates max MTU 607- ATT DB Util: attribute handle is returned for new Services and Characteristics 608 609### Fixed 610- Windows: retry serial port operations if not all bytes have been read/written 611- HFP: avoid buffer overflows setting up messages 612- SBC Decoder: improved error handling for invalid SBC audio data 613- GAP: fix Connection Parameter Response in Central role 614- ATT DB Util: update pointer to database in case of realloc 615- GATT Client: set UUID16 field if 16-bit UUID is stored as UUID128 616- GAP: release HCI Connnection after gap_le_conne 617- ATT: Exchanged MTU is propagate to ATT Server and GATT Client 618 619--- 620 621## Changes December 2017 622 623### Added 624- Introduced btstack_network.h network interface abstraction 625- btstack_network_posix implementation using Linux tun/tap interface 626- WICED: support for btstack_stdin (HAVE_STDIN) 627- GATT Server: Writes to GATT Client Characteristic Configuration are stored in TLV and restored on reconnect. The db.h file generated from db.gatt needs to be re-created. 628- TLV: global TLV instance available via btstack_tlv_get_instance() (src/btstack_tlv.h) 629- TLV: POSIX implementation that appends to a file on disk (platform/posix/btstack_tlv_posix.c 630- LE Device DB TLV: overwrite oldest entry if no free entries available 631- SM: allow to set fixed passkey in display role using sm_use_fixed_passkey_in_display_role 632- Example/hid_host_demo with HID parser and support for basic US keyboard layout 633- EM9304: custom HCI Transport implementation for EM9304 on top of btstack_em9304_spi.h platform abstraction only requires hal_em9304_spi.h to be implemented for new ports 634- Port for Apollo2 MCU with EM9304 (ports/apollo2-em9304) 635 636### Changed 637- panu_demo: uses btstack_network.h now 638- WICED: configure printf to replace Linefeed with CRLF 639- SBC: split btstack_sbc_bludroid.c into seperate encoder and decoder implementations 640 641### Fixed 642- RFCOMM: support connection requests during connection failure 643- L2CAP: support connection requests during connection failure 644- L2CAP: fix default remote MTU as 672 instead of 48 (Minimal MTU) 645- HCI: avoid double free during halting 646- SM: fixed reconnect using legacy pairing in slave role 647 648 649