Extend FIDO2 BLE support also for Linux

For Windows it was already added via gh#336,
so let's also add it for Linux.
Unpaired devices are ignored, the user has to pair independently
of libfido use using the bluetooth manager provided by the desktop
environment.

Author: akemnade

.github/workflows/alpine_builds.yml

@@ -28,7 +28,7 @@ jobs:
         apk -q update
         apk add build-base clang clang-analyzer cmake coreutils eudev-dev
         apk add git linux-headers openssl-dev sudo zlib-dev pcsc-lite-dev \
-          libcbor-dev
+          libcbor-dev elogind-dev
     - name: fix permissions on workdir
       run: chown root:wheel "${GITHUB_WORKSPACE}"
     - name: checkout libfido2

.github/workflows/codeql-analysis.yml

@@ -33,7 +33,7 @@ jobs:
       run: |
         sudo apt -q update
         sudo apt install -q -y libcbor-dev libudev-dev libz-dev original-awk \
-         libpcsclite-dev
+         libpcsclite-dev libsystemd-dev
         ./.actions/build-linux-gcc
     - name: perform codeql analysis
       uses: github/codeql-action/analyze@v2

.github/workflows/linux_builds.yml

@@ -38,7 +38,7 @@ jobs:
       run: |
         sudo apt -q update
         sudo apt install -q -y libcbor-dev libudev-dev libz-dev \
-          original-awk mandoc libpcsclite-dev
+          original-awk mandoc libpcsclite-dev libsystemd-dev
     - name: compiler
       env:
         CC: ${{ matrix.cc }}

.github/workflows/linux_fuzz.yml

@@ -28,7 +28,7 @@ jobs:
     - name: dependencies
       run: |
         sudo apt -q update
-        sudo apt install -q -y libudev-dev libpcsclite-dev
+        sudo apt install -q -y libudev-dev libpcsclite-dev libsystemd-dev
     - name: compiler
       env:
         CC: ${{ matrix.cc }}

.github/workflows/openssl3.yml

@@ -35,7 +35,7 @@ jobs:
       run: |
         sudo apt -q update
         sudo apt install -q -y libcbor-dev libudev-dev libz-dev \
-          original-awk mandoc libpcsclite-dev
+          original-awk mandoc libpcsclite-dev libsystemd-dev
         sudo apt remove -y libssl-dev
         if [ "${CC%-*}" == "clang" ]; then
           sudo ./.actions/setup_clang "${CC}"

CMakeLists.txt

@@ -44,6 +44,7 @@ option(USE_HIDAPI        "Use hidapi as the HID backend"           OFF)
 option(USE_PCSC          "Enable experimental PCSC support"        ON)
 option(USE_WINHELLO      "Abstract Windows Hello as a FIDO device" ON)
 option(NFC_LINUX         "Enable NFC support on Linux"             ON)
+option(BLE_LINUX         "Enable Bluetooth support on Linux"       ON)
 
 add_definitions(-D_FIDO_MAJOR=${FIDO_MAJOR})
 add_definitions(-D_FIDO_MINOR=${FIDO_MINOR})
@@ -216,6 +217,7 @@ if(MSVC)
 		add_definitions(-DUSE_WINHELLO)
 	endif()
 	set(NFC_LINUX OFF)
+	set(BLE_LINUX OFF)
 else()
 	include(FindPkgConfig)
 	pkg_search_module(CBOR libcbor)
@@ -255,6 +257,7 @@ else()
 		endif()
 	else()
 		set(NFC_LINUX OFF)
+		set(BLE_LINUX OFF)
 	endif()
 
 	if(MINGW)
@@ -285,6 +288,11 @@ else()
 		add_definitions(-DUSE_NFC)
 	endif()
 
+	if(BLE_LINUX)
+		add_definitions(-DUSE_BLE)
+		pkg_search_module(BLE libsystemd REQUIRED)
+	endif()
+
 	if(WIN32)
 		if(USE_WINHELLO)
 			add_definitions(-DUSE_WINHELLO)
@@ -392,13 +400,15 @@ include_directories(${PROJECT_SOURCE_DIR}/src)
 include_directories(${CBOR_INCLUDE_DIRS})
 include_directories(${CRYPTO_INCLUDE_DIRS})
 include_directories(${HIDAPI_INCLUDE_DIRS})
+include_directories(${BLE_INCLUDE_DIRS})
 include_directories(${PCSC_INCLUDE_DIRS})
 include_directories(${UDEV_INCLUDE_DIRS})
 include_directories(${ZLIB_INCLUDE_DIRS})
 
 link_directories(${CBOR_LIBRARY_DIRS})
 link_directories(${CRYPTO_LIBRARY_DIRS})
 link_directories(${HIDAPI_LIBRARY_DIRS})
+link_directories(${BLE_LIBRARY_DIRS})
 link_directories(${PCSC_LIBRARY_DIRS})
 link_directories(${UDEV_LIBRARY_DIRS})
 link_directories(${ZLIB_LIBRARY_DIRS})
@@ -468,6 +478,7 @@ message(STATUS "USE_HIDAPI: ${USE_HIDAPI}")
 message(STATUS "USE_PCSC: ${USE_PCSC}")
 message(STATUS "USE_WINHELLO: ${USE_WINHELLO}")
 message(STATUS "NFC_LINUX: ${NFC_LINUX}")
+message(STATUS "BLE_LINUX: ${BLE_LINUX}")
 
 if(BUILD_TESTS)
 	enable_testing()

src/CMakeLists.txt

@@ -51,6 +51,10 @@ if(FUZZ)
 	list(APPEND FIDO_SOURCES ../fuzz/wrap.c)
 endif()
 
+if(BLE_LINUX)
+	list(APPEND FIDO_SOURCES ble.c ble_linux.c)
+endif()
+
 if(NFC_LINUX)
 	list(APPEND FIDO_SOURCES netlink.c nfc.c nfc_linux.c)
 endif()
@@ -123,6 +127,7 @@ list(APPEND TARGET_LIBRARIES
 	${HIDAPI_LIBRARIES}
 	${ZLIB_LIBRARIES}
 	${PCSC_LIBRARIES}
+	${BLE_LIBRARIES}
 )
 
 # static library