diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 8b489f4fa..41d928fbc 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,621 +1,622 @@
 # Copyright (c) 2017 The Bitcoin developers
 
 project(bitcoind)
 
 set(CMAKE_CXX_STANDARD 14)
 
 # Default visibility is hidden on all targets.
 set(CMAKE_C_VISIBILITY_PRESET hidden)
 set(CMAKE_CXX_VISIBILITY_PRESET hidden)
 
 option(BUILD_BITCOIN_WALLET "Activate the wallet functionality" ON)
 option(BUILD_BITCOIN_ZMQ "Activate the ZeroMQ functionalities" ON)
 option(BUILD_BITCOIN_SEEDER "Build bitcoin-seeder" ON)
 option(BUILD_BITCOIN_CLI "Build bitcoin-cli" ON)
 option(BUILD_BITCOIN_TX "Build bitcoin-tx" ON)
 option(BUILD_BITCOIN_QT "Build bitcoin-qt" ON)
 option(BUILD_LIBBITCOINCONSENSUS "Build the bitcoinconsenus shared library" ON)
 option(ENABLE_BIP70 "Enable BIP70 (payment protocol) support in GUI" ON)
 option(ENABLE_HARDENING "Harden the executables" ON)
 option(ENABLE_REDUCE_EXPORTS "Reduce the amount of exported symbols" OFF)
 option(ENABLE_STATIC_LIBSTDCXX "Statically link libstdc++" OFF)
 option(ENABLE_GLIBC_BACK_COMPAT "Enable Glibc compatibility features" OFF)
 option(ENABLE_QRCODE "Enable QR code display" ON)
 option(ENABLE_UPNP "Enable UPnP support" ON)
 option(ENABLE_NOTIFICATIONS "Enable desktop notifications" ON)
 option(ENABLE_WERROR "Promote some compiler warnings to errors" OFF)
 option(START_WITH_UPNP "Make UPnP the default to map ports" OFF)
 option(ENABLE_CLANG_TIDY "Enable clang-tidy checks for Bitcoin ABC" OFF)
 option(ENABLE_PROFILING "Select the profiling tool to use" OFF)
 option(USE_LD_GOLD "Try to use gold as a linker if available" ON)
 
 # If ccache is available, then use it.
 find_program(CCACHE ccache)
 if(CCACHE)
 	message(STATUS "Using ccache: ${CCACHE}")
 	set(CMAKE_C_COMPILER_LAUNCHER ${CCACHE})
 	set(CMAKE_CXX_COMPILER_LAUNCHER ${CCACHE})
 endif(CCACHE)
 
 # Disable what we do not need for the native build.
 include(NativeExecutable)
 native_add_cmake_flags(
 	"-DBUILD_BITCOIN_WALLET=OFF"
 	"-DBUILD_BITCOIN_QT=OFF"
 	"-DBUILD_BITCOIN_ZMQ=OFF"
 	"-DENABLE_QRCODE=OFF"
 	"-DENABLE_UPNP=OFF"
 	# Forward the current setting for clang-tidy
 	"-DENABLE_CLANG_TIDY=${ENABLE_CLANG_TIDY}"
 )
 
 if(ENABLE_CLANG_TIDY)
 	include(ClangTidy)
 endif()
 
 if(ENABLE_SANITIZERS)
 	include(Sanitizers)
 	enable_sanitizers(${ENABLE_SANITIZERS})
 endif()
 
 include(AddCompilerFlags)
 
 if(USE_LD_GOLD)
 	add_linker_flags(-fuse-ld=gold)
 endif()
 
 # Prefer -g3, defaults to -g if unavailable
 foreach(LANGUAGE C CXX)
 	set(COMPILER_DEBUG_LEVEL -g)
 	check_compiler_flag(G3_IS_SUPPORTED ${LANGUAGE} -g3)
 	if(${G3_IS_SUPPORTED})
 		set(COMPILER_DEBUG_LEVEL -g3)
 	endif()
 	add_compile_options_to_configuration_for_language(Debug ${LANGUAGE} ${COMPILER_DEBUG_LEVEL})
 endforeach()
 
 # Define the debugging symbols DEBUG and DEBUG_LOCKORDER when the Debug build
 # type is selected.
 add_compile_definitions_to_configuration(Debug DEBUG DEBUG_LOCKORDER)
 
 # Add -ftrapv when building in Debug
 add_compile_options_to_configuration(Debug -ftrapv)
 
 # All versions of gcc that we commonly use for building are subject to bug
 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90348. To work around that, set
 # -fstack-reuse=none for all gcc builds. (Only gcc understands this flag)
 if(NOT ENABLE_CLANG_TIDY)
 	add_compiler_flags(-fstack-reuse=none)
 endif()
 
 # Ensure that WINDRES_PREPROC is enabled when using windres.
 if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	# Ensure that WINDRES_PREPROC is enabled when using windres.
 	list(APPEND CMAKE_RC_FLAGS "-DWINDRES_PREPROC")
 
 	# Build all static so there is no dll file to distribute.
 	add_linker_flags(-static)
 endif()
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
 	add_compile_definitions(MAC_OSX OBJC_OLD_DISPATCH_PROTOTYPES=0)
 endif()
 
 if(ENABLE_REDUCE_EXPORTS)
 	# Default visibility is set by CMAKE_<LANG>_VISIBILITY_PRESET, but this
 	# doesn't tell if the visibility set is effective.
 	# Check if the flag -fvisibility=hidden is supported, as using the hidden
 	# visibility is a requirement to reduce exports.
 	check_compiler_flag(HAS_CXX_FVISIBILITY CXX -fvisibility=hidden)
 	if(NOT HAS_CXX_FVISIBILITY)
 		message(FATAL_ERROR "Cannot set default symbol visibility. Use -DENABLE_REDUCE_EXPORTS=OFF.")
 	endif()
 
 	# Also hide symbols from static libraries
 	add_linker_flags(-Wl,--exclude-libs,ALL)
 endif()
 
 # Enable statically linking libstdc++
 if(ENABLE_STATIC_LIBSTDCXX)
 	add_linker_flags(-static-libstdc++)
 endif()
 
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 if(ENABLE_HARDENING)
 	# Enable stack protection
 	add_cxx_compiler_flags(-fstack-protector-all -Wstack-protector)
 
 	# Enable some buffer overflow checking
 	add_compiler_flags(-U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2)
 
 	# Enable ASLR (these flags are primarily targeting MinGw)
 	add_linker_flags(-Wl,--dynamicbase -Wl,--nxcompat -Wl,--high-entropy-va)
 
 	# Make the relocated sections read-only
 	add_linker_flags(-Wl,-z,relro -Wl,-z,now)
 
 	# CMake provides the POSITION_INDEPENDENT_CODE property to set PIC/PIE.
 	# Unfortunately setting the -pie linker flag this way require CMake >= 3.14,
 	# which is not widely distributed at the time of writing.
 	# FIXME: remove the fallback case when cmake >= 3.14 get enforced.
 	if(POLICY CMP0083)
 		cmake_policy(SET CMP0083 NEW)
 		include(CheckPIESupported)
 		check_pie_supported()
 	elseif(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		add_linker_flags(-pie)
 	endif()
 
 	if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		# MinGw provides its own libssp for stack smashing protection
 		link_libraries(ssp)
 	endif()
 endif()
 
 if(ENABLE_PROFILING MATCHES "gprof")
 	message(STATUS "Enable profiling with gprof")
 
 	# -pg is incompatible with -pie. Since hardening and profiling together
 	# doesn't make sense, we simply make them mutually exclusive here.
 	# Additionally, hardened toolchains may force -pie by default, in which
 	# case it needs to be turned off with -no-pie.
 	if(ENABLE_HARDENING)
 		message(FATAL_ERROR "Profiling with gprof requires disabling hardening with -DENABLE_HARDENING=OFF.")
 	endif()
 	add_linker_flags(-no-pie)
 
 	add_compiler_flags(-pg)
 	add_linker_flags(-pg)
 endif()
 
 # Enable warning
 add_c_compiler_flags(-Wnested-externs -Wstrict-prototypes)
 add_compiler_flags(
 	-Wall
 	-Wextra
 	-Wformat
 	-Wvla
 	-Wformat-security
 	-Wcast-align
 	-Wunused-parameter
 	-Wmissing-braces
 	-Wthread-safety-analysis
 	-Wshadow
 	-Wrange-loop-analysis
 	-Wredundant-decls
 	-Wredundant-move
 )
 
 option(EXTRA_WARNINGS "Enable extra warnings" OFF)
 if(EXTRA_WARNINGS)
 	add_cxx_compiler_flags(-Wsuggest-override)
 else()
 	add_compiler_flags(-Wno-unused-parameter)
 	add_compiler_flags(-Wno-implicit-fallthrough)
 endif()
 
 if(ENABLE_WERROR)
 	add_compiler_flags(
 		-Werror=vla
 		-Werror=thread-safety-analysis
 	)
 endif()
 
 # Create a target for OpenSSL
 include(BrewHelper)
 find_brew_prefix(OPENSSL_ROOT_DIR openssl)
 find_package(OpenSSL REQUIRED)
 
 # libtool style configure
 add_subdirectory(config)
 
 # libraries
 add_subdirectory(crypto)
 add_subdirectory(leveldb)
 add_subdirectory(secp256k1)
 add_subdirectory(univalue)
 
 # Find the git root, and returns the full path to the .git/logs/HEAD file if
 # it exists.
 function(find_git_head_logs_file RESULT)
 	find_package(Git)
 	if(GIT_FOUND)
 		execute_process(
 			COMMAND "${GIT_EXECUTABLE}" "rev-parse" "--show-toplevel"
 			WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
 			OUTPUT_VARIABLE GIT_ROOT
 			RESULT_VARIABLE GIT_RESULT
 			OUTPUT_STRIP_TRAILING_WHITESPACE
 			ERROR_QUIET
 		)
 
 		if(GIT_RESULT EQUAL 0)
 			set(GIT_LOGS_DIR "${GIT_ROOT}/.git/logs")
 			set(GIT_HEAD_LOGS_FILE "${GIT_LOGS_DIR}/HEAD")
 			# If the .git/logs/HEAD does not exist, create it
 			if(NOT EXISTS "${GIT_HEAD_LOGS_FILE}")
 				file(MAKE_DIRECTORY "${GIT_LOGS_DIR}")
 				file(TOUCH "${GIT_HEAD_LOGS_FILE}")
 			endif()
 			set(${RESULT} "${GIT_HEAD_LOGS_FILE}" PARENT_SCOPE)
 		endif()
 	endif()
 endfunction()
 
 find_git_head_logs_file(GIT_HEAD_LOGS_FILE)
 
 set(OBJ_DIR "${CMAKE_CURRENT_BINARY_DIR}/obj")
 file(MAKE_DIRECTORY "${OBJ_DIR}")
 set(BUILD_HEADER "${OBJ_DIR}/build.h")
 set(BUILD_HEADER_TMP "${BUILD_HEADER}.tmp")
 
 add_custom_command(
 	DEPENDS
 		"${GIT_HEAD_LOGS_FILE}"
 		"${CMAKE_SOURCE_DIR}/share/genbuild.sh"
 	OUTPUT
 		"${BUILD_HEADER}"
 	COMMAND
 		"${CMAKE_SOURCE_DIR}/share/genbuild.sh"
 		"${BUILD_HEADER_TMP}"
 		"${CMAKE_SOURCE_DIR}"
 	COMMAND
 		${CMAKE_COMMAND} -E copy_if_different "${BUILD_HEADER_TMP}" "${BUILD_HEADER}"
 	COMMAND
 		${CMAKE_COMMAND} -E remove "${BUILD_HEADER_TMP}"
 )
 
 # Because the Bitcoin ABc source code is disorganised, we
 # end up with a bunch of libraries without any apparent
 # cohesive structure. This is inherited from Bitcoin Core
 # and reflecting this.
 # TODO: Improve the structure once cmake is rocking.
 
 # Various completely unrelated features shared by all executables.
 add_library(util
 	chainparamsbase.cpp
 	clientversion.cpp
 	compat/glibc_sanity.cpp
 	compat/glibcxx_sanity.cpp
 	compat/strnlen.cpp
 	fs.cpp
 	logging.cpp
 	random.cpp
 	rcu.cpp
 	rpc/protocol.cpp
 	rpc/util.cpp
 	support/cleanse.cpp
 	support/lockedpool.cpp
 	sync.cpp
 	threadinterrupt.cpp
 	uint256.cpp
 	util/bytevectorhash.cpp
 	util/moneystr.cpp
 	util/strencodings.cpp
 	util/system.cpp
 	util/threadnames.cpp
 	util/time.cpp
 
 	# obj/build.h
 	"${BUILD_HEADER}"
 )
 
 target_compile_definitions(util PUBLIC HAVE_CONFIG_H HAVE_BUILD_INFO)
 target_include_directories(util
 	PUBLIC
 		.
 		# To access the config/ and obj/ directories
 		${CMAKE_CURRENT_BINARY_DIR}
 )
 
 if(ENABLE_GLIBC_BACK_COMPAT)
 	# glibc absorbed clock_gettime in 2.17. librt (its previous location) is
 	# safe to link in anyway for back-compat.
 	find_library(RT_LIBRARY rt)
 	target_link_libraries(util ${RT_LIBRARY})
 
 	# Wrap some glibc functions with ours
 	add_linker_flags(-Wl,--wrap=__divmoddi4)
 	add_linker_flags(-Wl,--wrap=log2f)
 
 	if(NOT HAVE_LARGE_FILE_SUPPORT)
 		add_linker_flags(-Wl,--wrap=fcntl -Wl,--wrap=fcntl64)
 	endif()
 
 	target_sources(util PRIVATE compat/glibc_compat.cpp)
 endif()
 
 # Enable LFS (Large File Support) on targets that don't have it natively.
 if(NOT HAVE_LARGE_FILE_SUPPORT)
 	add_compiler_flags(-D_FILE_OFFSET_BITS=64)
 	add_linker_flags(-Wl,--large-address-aware)
 endif()
 
 # Target specific configs
 if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	set(Boost_USE_STATIC_LIBS ON)
 	set(Boost_THREADAPI win32)
 
 	find_package(SHLWAPI REQUIRED)
 	# We cannot use the imported target here, because cmake will introduce an
 	# -isystem compilation directive and cause the build to fail with MinGw.
 	# This comes from a couple cmake bugs:
 	#  - https://gitlab.kitware.com/cmake/cmake/issues/16291
 	#  - https://gitlab.kitware.com/cmake/cmake/issues/19095
 	# These issues are solved from cmake 3.14.1. Once this version is enforced,
 	# the following can be used:
 	# target_link_libraries(util SHLWAPI::shlwapi)
 	target_link_libraries(util ${SHLWAPI_LIBRARIES})
 	target_include_directories(util PUBLIC ${SHLWAPI_INCLUDE_DIRS})
 
 	find_library(WS2_32_LIBRARY NAMES ws2_32)
 	target_link_libraries(util ${WS2_32_LIBRARY})
 
 	target_compile_definitions(util PUBLIC BOOST_THREAD_USE_LIB)
 endif()
 
 # Boost packages
 set(BOOST_PACKAGES_REQUIRED chrono filesystem thread)
 
 function(prepend var prefix)
 	set(listVar "")
 	foreach(f ${ARGN})
 		list(APPEND listVar "${prefix}${f}")
 	endforeach(f)
 	set(${var} "${listVar}" PARENT_SCOPE)
 endfunction(prepend)
 
 prepend(BOOST_LIBRARIES "Boost::" ${BOOST_PACKAGES_REQUIRED})
 
 find_package(Boost 1.58 REQUIRED ${BOOST_PACKAGES_REQUIRED})
 target_link_libraries(util univalue crypto ${BOOST_LIBRARIES})
 
 # Make sure boost uses std::atomic (it doesn't before 1.63)
 target_compile_definitions(util PUBLIC BOOST_SP_USE_STD_ATOMIC BOOST_AC_USE_STD_ATOMIC)
 
 # More completely unrelated features shared by all executables.
 # Because nothing says this is different from util than "common"
 add_library(common
 	amount.cpp
 	base58.cpp
 	cashaddr.cpp
 	cashaddrenc.cpp
 	chainparams.cpp
 	config.cpp
 	consensus/merkle.cpp
 	coins.cpp
 	compressor.cpp
 	feerate.cpp
 	globals.cpp
 	core_read.cpp
 	core_write.cpp
 	key.cpp
 	key_io.cpp
 	keystore.cpp
 	netaddress.cpp
 	netbase.cpp
 	primitives/block.cpp
 	protocol.cpp
 	scheduler.cpp
 	versionbitsinfo.cpp
 	warnings.cpp
 )
 
 target_link_libraries(common util secp256k1)
 
 # script library
 add_library(script
 	script/bitfield.cpp
 	script/descriptor.cpp
 	script/interpreter.cpp
 	script/ismine.cpp
 	script/script.cpp
 	script/script_error.cpp
 	script/sigencoding.cpp
 	script/sign.cpp
 	script/standard.cpp
 )
 
 target_link_libraries(script common)
 
 # libbitcoinconsensus
 add_library(bitcoinconsensus
 	arith_uint256.cpp
 	hash.cpp
 	primitives/transaction.cpp
 	pubkey.cpp
 	uint256.cpp
 	util/strencodings.cpp
 )
 
 target_link_libraries(bitcoinconsensus script)
 
 include(InstallationHelper)
 if(BUILD_LIBBITCOINCONSENSUS)
 	target_compile_definitions(bitcoinconsensus
 		PUBLIC
 			BUILD_BITCOIN_INTERNAL
 			HAVE_CONSENSUS_LIB
 	)
 
 	install_shared_library(bitcoinconsensus
 		script/bitcoinconsensus.cpp
 		PUBLIC_HEADER script/bitcoinconsensus.h
 	)
 endif()
 
 # Bitcoin server facilities
 add_library(server
 	addrdb.cpp
 	addrman.cpp
 	avalanche.cpp
 	banman.cpp
 	bloom.cpp
 	blockencodings.cpp
 	blockfilter.cpp
 	chain.cpp
 	checkpoints.cpp
 	config.cpp
 	consensus/activation.cpp
 	consensus/tx_verify.cpp
 	dbwrapper.cpp
 	flatfile.cpp
 	globals.cpp
 	httprpc.cpp
 	httpserver.cpp
 	index/base.cpp
 	index/txindex.cpp
 	init.cpp
 	interfaces/chain.cpp
 	interfaces/handler.cpp
 	interfaces/node.cpp
 	merkleblock.cpp
 	miner.cpp
 	minerfund.cpp
 	net.cpp
 	net_processing.cpp
 	noui.cpp
 	outputtype.cpp
 	policy/fees.cpp
 	policy/mempool.cpp
 	policy/policy.cpp
 	pow.cpp
 	rest.cpp
 	rpc/abc.cpp
+	rpc/avalanche.cpp
 	rpc/blockchain.cpp
 	rpc/command.cpp
 	rpc/jsonrpcrequest.cpp
 	rpc/mining.cpp
 	rpc/misc.cpp
 	rpc/net.cpp
 	rpc/rawtransaction.cpp
 	rpc/server.cpp
 	script/scriptcache.cpp
 	script/sigcache.cpp
 	shutdown.cpp
 	timedata.cpp
 	torcontrol.cpp
 	txdb.cpp
 	txmempool.cpp
 	ui_interface.cpp
 	validation.cpp
 	validationinterface.cpp
 	versionbits.cpp
 )
 
 target_include_directories(server PRIVATE leveldb/helpers/memenv)
 
 # This require libevent
 set(EVENT_MIN_VERSION 2.0.22)
 find_package(Event ${EVENT_MIN_VERSION} REQUIRED COMPONENTS event)
 
 target_link_libraries(server
 	Event::event
 	bitcoinconsensus
 	leveldb
 	memenv
 )
 
 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	find_package(Event ${EVENT_MIN_VERSION} REQUIRED COMPONENTS pthreads)
 	target_link_libraries(server Event::pthreads)
 endif()
 
 if(ENABLE_UPNP)
 	find_package(MiniUPnPc 1.5 REQUIRED)
 	target_link_libraries(server MiniUPnPc::miniupnpc)
 
 	if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		find_library(IPHLPAPI_LIBRARY NAMES iphlpapi)
 		if(NOT IPHLPAPI_LIBRARY)
 			message(FATAL_ERROR "Lib iphlpapi is missing")
 		endif()
 		target_link_libraries(server ${IPHLPAPI_LIBRARY})
 
 		target_compile_definitions(server
 			PUBLIC -DSTATICLIB
 			PUBLIC -DMINIUPNP_STATICLIB
 		)
 	endif()
 endif()
 
 # Test suite.
 add_subdirectory(test)
 
 # Benchmark suite.
 add_subdirectory(bench)
 
 # Wallet
 if(BUILD_BITCOIN_WALLET)
 	add_subdirectory(wallet)
 	target_link_libraries(server wallet)
 	# There is a circular dependency between wallet and server, see:
 	# https://github.com/bitcoin/bitcoin/pull/14437#discussion_r226237048
 	target_link_libraries(wallet server)
 else()
 	target_sources(server PRIVATE dummywallet.cpp)
 endif()
 
 # ZeroMQ
 if(BUILD_BITCOIN_ZMQ)
 	add_subdirectory(zmq)
 	target_link_libraries(server zmq)
 endif()
 
 # RPC client support
 add_library(rpcclient rpc/client.cpp)
 target_link_libraries(rpcclient univalue util)
 
 # bitcoin-seeder
 if(BUILD_BITCOIN_SEEDER)
 	add_subdirectory(seeder)
 endif()
 
 include(BinaryTest)
 
 # bitcoin-cli
 if(BUILD_BITCOIN_CLI)
 	add_executable(bitcoin-cli bitcoin-cli.cpp)
 	if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		target_sources(bitcoin-cli PRIVATE bitcoin-cli-res.rc)
 	endif()
 
 	target_link_libraries(bitcoin-cli common rpcclient Event::event)
 
 	add_to_symbols_check(bitcoin-cli)
 	add_to_security_check(bitcoin-cli)
 
 	install_target(bitcoin-cli)
 endif()
 
 # bitcoin-tx
 if(BUILD_BITCOIN_TX)
 	add_executable(bitcoin-tx bitcoin-tx.cpp)
 	if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		target_sources(bitcoin-tx PRIVATE bitcoin-tx-res.rc)
 	endif()
 
 	target_link_libraries(bitcoin-tx bitcoinconsensus)
 
 	add_to_symbols_check(bitcoin-tx)
 	add_to_security_check(bitcoin-tx)
 
 	install_target(bitcoin-tx)
 endif()
 
 # bitcoind
 add_executable(bitcoind bitcoind.cpp)
 target_link_libraries(bitcoind server)
 if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	target_sources(bitcoind PRIVATE bitcoind-res.rc)
 endif()
 add_to_symbols_check(bitcoind)
 add_to_security_check(bitcoind)
 
 install_target(bitcoind)
 
 # Bitcoin-qt
 if(BUILD_BITCOIN_QT)
 	add_subdirectory(qt)
 endif()
diff --git a/src/Makefile.am b/src/Makefile.am
index a79e53c95..32b2707e0 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,715 +1,716 @@
 # Copyright (c) 2013-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 DIST_SUBDIRS = secp256k1 univalue
 
 AM_LDFLAGS = $(PTHREAD_CFLAGS) $(LIBTOOL_LDFLAGS) $(HARDENED_LDFLAGS) $(GPROF_LDFLAGS) $(SANITIZER_LDFLAGS)
 AM_CXXFLAGS = $(DEBUG_CXXFLAGS) $(HARDENED_CXXFLAGS) $(WARN_CXXFLAGS) $(NOWARN_CXXFLAGS) $(ERROR_CXXFLAGS) $(GPROF_CXXFLAGS) $(SANITIZER_CXXFLAGS)
 AM_CPPFLAGS = $(DEBUG_CPPFLAGS) $(HARDENED_CPPFLAGS)
 AM_LIBTOOLFLAGS = --preserve-dup-deps
 EXTRA_LIBRARIES =
 
 if EMBEDDED_UNIVALUE
 LIBUNIVALUE = univalue/libunivalue.la
 
 $(LIBUNIVALUE): $(wildcard univalue/lib/*) $(wildcard univalue/include/*)
 	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) -C $(@D) $(@F)
 else
 LIBUNIVALUE = $(UNIVALUE_LIBS)
 endif
 
 BITCOIN_INCLUDES=-I$(builddir) $(BDB_CPPFLAGS) $(BOOST_CPPFLAGS) $(LEVELDB_CPPFLAGS) $(CRYPTO_CFLAGS) $(SSL_CFLAGS)
 
 BITCOIN_INCLUDES += -I$(srcdir)/secp256k1/include
 BITCOIN_INCLUDES += $(UNIVALUE_CFLAGS)
 
 BITCOIN_SEEDER_INCLUDES = -I$(srcdir)/seeder
 BITCOIN_SEEDER_INCLUDES += $(BITCOIN_INCLUDES)
 
 LIBBITCOIN_SERVER=libbitcoin_server.a
 LIBBITCOIN_COMMON=libbitcoin_common.a
 LIBBITCOIN_CONSENSUS=libbitcoin_consensus.a
 LIBBITCOIN_CLI=libbitcoin_cli.a
 LIBBITCOIN_UTIL=libbitcoin_util.a
 LIBBITCOIN_CRYPTO_BASE=crypto/libbitcoin_crypto_base.a
 LIBBITCOINQT=qt/libbitcoinqt.a
 LIBSECP256K1=secp256k1/libsecp256k1.la
 
 if ENABLE_ZMQ
 LIBBITCOIN_ZMQ=libbitcoin_zmq.a
 endif
 if BUILD_BITCOIN_LIBS
 LIBBITCOINCONSENSUS=libbitcoinconsensus.la
 endif
 if BUILD_BITCOIN_SEEDER
 LIBBITCOIN_SEEDER=libbitcoin_seeder.a
 endif
 if ENABLE_WALLET
 LIBBITCOIN_WALLET=libbitcoin_wallet.a
 endif
 
 LIBBITCOIN_CRYPTO= $(LIBBITCOIN_CRYPTO_BASE)
 if ENABLE_SSE41
 LIBBITCOIN_CRYPTO_SSE41 = crypto/libbitcoin_crypto_sse41.a
 LIBBITCOIN_CRYPTO += $(LIBBITCOIN_CRYPTO_SSE41)
 endif
 if ENABLE_AVX2
 LIBBITCOIN_CRYPTO_AVX2 = crypto/libbitcoin_crypto_avx2.a
 LIBBITCOIN_CRYPTO += $(LIBBITCOIN_CRYPTO_AVX2)
 endif
 if ENABLE_SHANI
 LIBBITCOIN_CRYPTO_SHANI = crypto/libbitcoin_crypto_shani.a
 LIBBITCOIN_CRYPTO += $(LIBBITCOIN_CRYPTO_SHANI)
 endif
 
 $(LIBSECP256K1): $(wildcard secp256k1/src/*) $(wildcard secp256k1/include/*)
 	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) -C $(@D) $(@F)
 
 # Make is not made aware of per-object dependencies to avoid limiting building parallelization
 # But to build the less dependent modules first, we manually select their order here:
 EXTRA_LIBRARIES += \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_COMMON) \
   $(LIBBITCOIN_CONSENSUS) \
   $(LIBBITCOIN_SERVER) \
   $(LIBBITCOIN_CLI) \
   $(LIBBITCOIN_SEEDER) \
   $(LIBBITCOIN_WALLET) \
   $(LIBBITCOIN_ZMQ)
 
 lib_LTLIBRARIES = $(LIBBITCOINCONSENSUS)
 
 bin_PROGRAMS =
 noinst_PROGRAMS =
 TESTS =
 BENCHMARKS =
 
 if BUILD_BITCOIND
   bin_PROGRAMS += bitcoind
 endif
 
 if BUILD_BITCOIN_SEEDER
   bin_PROGRAMS += bitcoin-seeder
 endif
 
 if BUILD_BITCOIN_UTILS
   bin_PROGRAMS += bitcoin-cli bitcoin-tx
 endif
 
 .PHONY: FORCE check-symbols check-security
 # bitcoin core #
 BITCOIN_CORE_H = \
   addrdb.h \
   addrman.h \
   attributes.h \
   avalanche.h \
   banman.h \
   base58.h \
   bloom.h \
   blockencodings.h \
   blockfileinfo.h \
   blockfilter.h \
   blockindexworkcomparator.h \
   blockstatus.h \
   blockvalidity.h \
   cashaddr.h \
   cashaddrenc.h \
   chain.h \
   chainparams.h \
   chainparamsbase.h \
   chainparamsconstants.h \
   chainparamsseeds.h \
   checkpoints.h \
   checkqueue.h \
   clientversion.h \
   coins.h \
   compat.h \
   compat/assumptions.h \
   compat/byteswap.h \
   compat/endian.h \
   compat/sanity.h \
   compat/setenv.h \
   compressor.h \
   config.h \
   consensus/activation.h \
   consensus/consensus.h \
   consensus/tx_verify.h \
   core_io.h \
   core_memusage.h \
   cuckoocache.h \
   flatfile.h \
   fs.h \
   globals.h \
   httprpc.h \
   httpserver.h \
   index/base.h \
   index/txindex.h \
   indirectmap.h \
   init.h \
   interfaces/chain.h \
   interfaces/handler.h \
   interfaces/node.h \
   interfaces/wallet.h \
   key.h \
   key_io.h \
   keystore.h \
   dbwrapper.h \
   limitedmap.h \
   logging.h \
   memusage.h \
   merkleblock.h \
   miner.h \
   minerfund.h \
   net.h \
   net_processing.h \
   netaddress.h \
   netbase.h \
   netmessagemaker.h \
   noui.h \
   outputtype.h \
   policy/fees.h \
   policy/mempool.h \
   policy/policy.h \
   pow.h \
   protocol.h \
   radix.h \
   random.h \
   rcu.h \
   reverse_iterator.h \
   reverselock.h \
   rpc/blockchain.h \
   rpc/client.h \
   rpc/command.h \
   rpc/jsonrpcrequest.h \
   rpc/mining.h \
   rpc/protocol.h \
   rpc/rawtransaction.h \
   rpc/server.h \
   rpc/register.h \
   rpc/util.h \
   rwcollection.h \
   scheduler.h \
   script/descriptor.h \
   script/ismine.h \
   script/scriptcache.h \
   script/sigcache.h \
   script/sign.h \
   script/standard.h \
   shutdown.h \
   streams.h \
   support/allocators/secure.h \
   support/allocators/zeroafterfree.h \
   support/cleanse.h \
   support/events.h \
   support/lockedpool.h \
   sync.h \
   threadsafety.h \
   threadinterrupt.h \
   timedata.h \
   torcontrol.h \
   txdb.h \
   txmempool.h \
   ui_interface.h \
   undo.h \
   util/bitmanip.h \
   util/bytevectorhash.h \
   util/moneystr.h \
   util/system.h \
   util/threadnames.h \
   util/time.h \
   validation.h \
   validationinterface.h \
   versionbits.h \
   versionbitsinfo.h \
   walletinitinterface.h \
   wallet/coincontrol.h \
   wallet/coinselection.h \
   wallet/crypter.h \
   wallet/db.h \
   wallet/finaltx.h \
   wallet/rpcdump.h \
   wallet/fees.h \
   wallet/rpcwallet.h \
   wallet/wallet.h \
   wallet/walletdb.h \
   wallet/walletutil.h \
   warnings.h \
   zmq/zmqabstractnotifier.h \
   zmq/zmqconfig.h\
   zmq/zmqnotificationinterface.h \
   zmq/zmqpublishnotifier.h \
   zmq/zmqrpc.h
 
 
 obj/build.h: FORCE
 	@$(MKDIR_P) "$(builddir)/obj"
 	@$(top_srcdir)/share/genbuild.sh "$(abs_top_builddir)/src/obj/build.h" \
 	  "$(abs_top_srcdir)"
 libbitcoin_util_a-clientversion.$(OBJEXT): obj/build.h
 
 # server: shared between bitcoind and bitcoin-qt
 libbitcoin_server_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(MINIUPNPC_CPPFLAGS) $(EVENT_CFLAGS) $(EVENT_PTHREADS_CFLAGS)
 libbitcoin_server_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_server_a_SOURCES = \
   addrdb.cpp \
   addrman.cpp \
   avalanche.cpp \
   banman.cpp \
   bloom.cpp \
   blockencodings.cpp \
   blockfilter.cpp \
   chain.cpp \
   checkpoints.cpp \
   config.cpp \
   consensus/activation.cpp \
   consensus/tx_verify.cpp \
   flatfile.cpp \
   globals.cpp \
   httprpc.cpp \
   httpserver.cpp \
   index/base.cpp \
   index/txindex.cpp \
   init.cpp \
   interfaces/chain.cpp \
   interfaces/handler.cpp \
   interfaces/node.cpp \
   dbwrapper.cpp \
   merkleblock.cpp \
   miner.cpp \
   minerfund.cpp \
   net.cpp \
   net_processing.cpp \
   noui.cpp \
   outputtype.cpp \
   policy/fees.cpp \
   policy/mempool.cpp \
   policy/policy.cpp \
   pow.cpp \
   rest.cpp \
   rpc/abc.cpp \
+  rpc/avalanche.cpp \
   rpc/blockchain.cpp \
   rpc/command.cpp \
   rpc/jsonrpcrequest.cpp \
   rpc/mining.cpp \
   rpc/misc.cpp \
   rpc/net.cpp \
   rpc/rawtransaction.cpp \
   rpc/server.cpp \
   script/scriptcache.cpp \
   script/sigcache.cpp \
   shutdown.cpp \
   timedata.cpp \
   torcontrol.cpp \
   txdb.cpp \
   txmempool.cpp \
   ui_interface.cpp \
   validation.cpp \
   validationinterface.cpp \
   versionbits.cpp \
   $(BITCOIN_CORE_H)
 
 if !ENABLE_WALLET
 libbitcoin_server_a_SOURCES += dummywallet.cpp
 endif
 
 if ENABLE_ZMQ
 libbitcoin_zmq_a_CPPFLAGS = $(BITCOIN_INCLUDES) $(ZMQ_CFLAGS)
 libbitcoin_zmq_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_zmq_a_SOURCES = \
   zmq/zmqabstractnotifier.cpp \
   zmq/zmqnotificationinterface.cpp \
   zmq/zmqpublishnotifier.cpp \
   zmq/zmqrpc.cpp
 endif
 
 
 # wallet: shared between bitcoind and bitcoin-qt, but only linked
 # when wallet enabled
 libbitcoin_wallet_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_wallet_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_wallet_a_SOURCES = \
   interfaces/wallet.cpp \
   wallet/coincontrol.cpp \
   wallet/crypter.cpp \
   wallet/coinselection.cpp \
   wallet/db.cpp \
   wallet/finaltx.cpp \
   wallet/fees.cpp \
   wallet/init.cpp \
   wallet/rpcdump.cpp \
   wallet/rpcwallet.cpp \
   wallet/wallet.cpp \
   wallet/walletdb.cpp \
   wallet/walletutil.cpp \
   $(BITCOIN_CORE_H)
 
 # crypto primitives library
 crypto_libbitcoin_crypto_base_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_base_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_base_a_SOURCES = \
   crypto/aes.cpp \
   crypto/aes.h \
   crypto/chacha20.h \
   crypto/chacha20.cpp \
   crypto/common.h \
   crypto/hmac_sha256.cpp \
   crypto/hmac_sha256.h \
   crypto/hmac_sha512.cpp \
   crypto/hmac_sha512.h \
   crypto/ripemd160.cpp \
   crypto/ripemd160.h \
   crypto/sha1.cpp \
   crypto/sha1.h \
   crypto/sha256.cpp \
   crypto/sha256.h \
   crypto/sha512.cpp \
   crypto/sha512.h \
   crypto/siphash.cpp \
   crypto/siphash.h
 
 if USE_ASM
 crypto_libbitcoin_crypto_base_a_SOURCES += crypto/sha256_sse4.cpp
 endif
 
 crypto_libbitcoin_crypto_sse41_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_sse41_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_sse41_a_CXXFLAGS += $(SSE41_CXXFLAGS)
 crypto_libbitcoin_crypto_sse41_a_CPPFLAGS += -DENABLE_SSE41
 crypto_libbitcoin_crypto_sse41_a_SOURCES = crypto/sha256_sse41.cpp
 
 crypto_libbitcoin_crypto_avx2_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_avx2_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_avx2_a_CXXFLAGS += $(AVX2_CXXFLAGS)
 crypto_libbitcoin_crypto_avx2_a_CPPFLAGS += -DENABLE_AVX2
 crypto_libbitcoin_crypto_avx2_a_SOURCES = crypto/sha256_avx2.cpp
 
 crypto_libbitcoin_crypto_shani_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_shani_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_shani_a_CXXFLAGS += $(SHANI_CXXFLAGS)
 crypto_libbitcoin_crypto_shani_a_CPPFLAGS += -DENABLE_SHANI
 crypto_libbitcoin_crypto_shani_a_SOURCES = crypto/sha256_shani.cpp
 
 # consensus: shared between all executables that validate any consensus rules.
 libbitcoin_consensus_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_consensus_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_consensus_a_SOURCES = \
   amount.h \
   arith_uint256.cpp \
   arith_uint256.h \
   consensus/merkle.cpp \
   consensus/merkle.h \
   consensus/params.h \
   consensus/validation.h \
   feerate.h \
   hash.cpp \
   hash.h \
   prevector.h \
   primitives/block.cpp \
   primitives/block.h \
   primitives/transaction.cpp \
   primitives/transaction.h \
   primitives/txid.h \
   pubkey.cpp \
   pubkey.h \
   script/bitcoinconsensus.cpp \
   script/bitfield.cpp \
   script/bitfield.h \
   script/sighashtype.h \
   script/interpreter.cpp \
   script/interpreter.h \
   script/script.cpp \
   script/script.h \
   script/script_error.cpp \
   script/script_error.h \
   script/script_flags.h \
   script/script_metrics.h \
   script/sigencoding.cpp \
   script/sigencoding.h \
   serialize.h \
   span.h \
   tinyformat.h \
   uint256.cpp \
   uint256.h \
   util/strencodings.cpp \
   util/strencodings.h \
   version.h
 
 # common: shared between bitcoind, and bitcoin-qt and non-server tools
 libbitcoin_common_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_common_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_common_a_SOURCES = \
   amount.cpp \
   base58.cpp \
   cashaddr.cpp \
   cashaddrenc.cpp \
   chainparams.cpp \
   config.cpp \
   coins.cpp \
   compressor.cpp \
   feerate.cpp \
   globals.cpp \
   core_read.cpp \
   core_write.cpp \
   key.cpp \
   key_io.cpp \
   keystore.cpp \
   netaddress.cpp \
   netbase.cpp \
   protocol.cpp \
   scheduler.cpp \
   script/descriptor.cpp \
   script/ismine.cpp \
   script/sign.cpp \
   script/standard.cpp \
   versionbitsinfo.cpp \
   warnings.cpp \
   $(BITCOIN_CORE_H)
 
 # util: shared between all executables.
 # This library *must* be included to make sure that the glibc
 # backward-compatibility objects and their sanity checks are linked.
 libbitcoin_util_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_util_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_util_a_SOURCES = \
   support/lockedpool.cpp \
   chainparamsbase.cpp \
   clientversion.cpp \
   compat/glibc_sanity.cpp \
   compat/glibcxx_sanity.cpp \
   compat/strnlen.cpp \
   fs.cpp \
   logging.cpp \
   random.cpp \
   rcu.cpp \
   rpc/protocol.cpp \
   rpc/util.cpp \
   support/cleanse.cpp \
   sync.cpp \
   threadinterrupt.cpp \
   uint256.cpp \
   uint256.h \
   util/system.cpp \
   util/moneystr.cpp \
   util/strencodings.cpp \
   util/threadnames.cpp \
   util/time.cpp \
   util/bytevectorhash.cpp \
   $(BITCOIN_CORE_H)
 
 if GLIBC_BACK_COMPAT
 libbitcoin_util_a_SOURCES += compat/glibc_compat.cpp
 AM_LDFLAGS += $(COMPAT_LDFLAGS)
 endif
 
 # cli: shared between bitcoin-cli and bitcoin-qt
 libbitcoin_cli_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_cli_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_cli_a_SOURCES = \
   rpc/client.cpp \
   $(BITCOIN_CORE_H)
 
 # seeder library
 libbitcoin_seeder_a_CPPFLAGS = $(AM_CPPFLAGS) $(PIE_FLAGS) $(BITCOIN_SEEDER_INCLUDES)
 libbitcoin_seeder_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_seeder_a_SOURCES = \
   seeder/bitcoin.cpp \
   seeder/bitcoin.h \
   seeder/db.cpp \
   seeder/db.h \
   seeder/dns.cpp \
   seeder/dns.h \
   seeder/util.h
 
 nodist_libbitcoin_util_a_SOURCES = $(srcdir)/obj/build.h
 #
 
 # bitcoind binary #
 bitcoind_SOURCES = bitcoind.cpp
 bitcoind_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 bitcoind_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoind_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 if TARGET_WINDOWS
 bitcoind_SOURCES += bitcoind-res.rc
 endif
 
 bitcoind_LDADD = \
   $(LIBBITCOIN_SERVER) \
   $(LIBBITCOIN_WALLET) \
   $(LIBBITCOIN_SERVER) \
   $(LIBBITCOIN_COMMON) \
   $(LIBUNIVALUE) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_ZMQ) \
   $(LIBBITCOIN_CONSENSUS) \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBLEVELDB) \
   $(LIBLEVELDB_SSE42) \
   $(LIBMEMENV) \
   $(LIBSECP256K1)
 
 bitcoind_LDADD += $(BOOST_LIBS) $(BDB_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(MINIUPNPC_LIBS) $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(ZMQ_LIBS)
 
 # bitcoin-cli binary #
 bitcoin_cli_SOURCES = bitcoin-cli.cpp
 bitcoin_cli_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(EVENT_CFLAGS)
 bitcoin_cli_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoin_cli_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 if TARGET_WINDOWS
 bitcoin_cli_SOURCES += bitcoin-cli-res.rc
 endif
 
 bitcoin_cli_LDADD = \
   $(LIBBITCOIN_CLI) \
   $(LIBUNIVALUE) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_CRYPTO)
 
 bitcoin_cli_LDADD += $(BOOST_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(EVENT_LIBS)
 #
 
 # bitcoin-seeder binary #
 bitcoin_seeder_SOURCES = seeder/main.cpp
 bitcoin_seeder_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_SEEDER_INCLUDES)
 bitcoin_seeder_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoin_seeder_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 bitcoin_seeder_LDADD = \
   $(LIBBITCOIN_SEEDER) \
   $(LIBBITCOIN_COMMON) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBBITCOIN_CONSENSUS)
 
 bitcoin_seeder_LDADD += $(BOOST_LIBS) $(CRYPTO_LIBS)
 #
 
 # bitcoin-tx binary #
 bitcoin_tx_SOURCES = bitcoin-tx.cpp
 bitcoin_tx_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 bitcoin_tx_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoin_tx_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 if TARGET_WINDOWS
 bitcoin_tx_SOURCES += bitcoin-tx-res.rc
 endif
 
 bitcoin_tx_LDADD = \
   $(LIBUNIVALUE) \
   $(LIBBITCOIN_COMMON) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_CONSENSUS) \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBSECP256K1)
 
 bitcoin_tx_LDADD += $(BOOST_LIBS) $(CRYPTO_LIBS)
 #
 
 # bitcoinconsensus library #
 if BUILD_BITCOIN_LIBS
 include_HEADERS = script/bitcoinconsensus.h
 libbitcoinconsensus_la_SOURCES = $(crypto_libbitcoin_crypto_base_a_SOURCES) $(libbitcoin_consensus_a_SOURCES)
 
 if GLIBC_BACK_COMPAT
   libbitcoinconsensus_la_SOURCES += compat/glibc_compat.cpp
 endif
 
 libbitcoinconsensus_la_LDFLAGS = $(AM_LDFLAGS) -no-undefined $(RELDFLAGS)
 libbitcoinconsensus_la_LIBADD = $(LIBSECP256K1)
 libbitcoinconsensus_la_CPPFLAGS = $(AM_CPPFLAGS) -I$(builddir)/obj -I$(srcdir)/secp256k1/include -DBUILD_BITCOIN_INTERNAL
 libbitcoinconsensus_la_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 
 endif
 #
 
 CTAES_DIST =  crypto/ctaes/bench.c
 CTAES_DIST += crypto/ctaes/ctaes.c
 CTAES_DIST += crypto/ctaes/ctaes.h
 CTAES_DIST += crypto/ctaes/README.md
 CTAES_DIST += crypto/ctaes/test.c
 
 CLEANFILES = $(EXTRA_LIBRARIES)
 
 CLEANFILES += *.gcda *.gcno
 CLEANFILES += compat/*.gcda compat/*.gcno
 CLEANFILES += consensus/*.gcda consensus/*.gcno
 CLEANFILES += crypto/*.gcda crypto/*.gcno
 CLEANFILES += policy/*.gcda policy/*.gcno
 CLEANFILES += primitives/*.gcda primitives/*.gcno
 CLEANFILES += script/*.gcda script/*.gcno
 CLEANFILES += support/*.gcda support/*.gcno
 CLEANFILES += univalue/*.gcda univalue/*.gcno
 CLEANFILES += wallet/*.gcda wallet/*.gcno
 CLEANFILES += wallet/test/*.gcda wallet/test/*.gcno
 CLEANFILES += zmq/*.gcda zmq/*.gcno
 CLEANFILES += obj/build.h
 
 EXTRA_DIST = $(CTAES_DIST)
 
 
 config/bitcoin-config.h: config/stamp-h1
 	@$(MAKE) -C $(top_builddir) $(subdir)/$(@)
 config/stamp-h1: $(top_srcdir)/$(subdir)/config/bitcoin-config.h.in $(top_builddir)/config.status
 	$(AM_V_at)$(MAKE) -C $(top_builddir) $(subdir)/$(@)
 $(top_srcdir)/$(subdir)/config/bitcoin-config.h.in:  $(am__configure_deps)
 	$(AM_V_at)$(MAKE) -C $(top_srcdir) $(subdir)/config/bitcoin-config.h.in
 
 clean-local:
 	-$(MAKE) -C secp256k1 clean
 	-$(MAKE) -C univalue clean
 	-rm -f leveldb/*/*.gcda leveldb/*/*.gcno leveldb/helpers/memenv/*.gcda leveldb/helpers/memenv/*.gcno
 	-rm -rf test/__pycache__
 
 .rc.o:
 	@test -f $(WINDRES)
 	## FIXME: How to get the appropriate modulename_CPPFLAGS in here?
 	$(AM_V_GEN) $(WINDRES) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(CPPFLAGS) -DWINDRES_PREPROC -i $< -o $@
 
 .mm.o:
 	$(AM_V_CXX) $(OBJCXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
 	  $(CPPFLAGS) $(AM_CXXFLAGS) $(QT_INCLUDES) $(AM_CXXFLAGS) $(PIE_FLAGS) $(CXXFLAGS) -c -o $@ $<
 
 check-symbols: $(bin_PROGRAMS)
 if GLIBC_BACK_COMPAT
 	@echo "Checking glibc back compat..."
 	$(AM_V_at) READELF=$(READELF) CPPFILT=$(CPPFILT) $(top_srcdir)/contrib/devtools/symbol-check.py < $(bin_PROGRAMS)
 endif
 
 check-security: $(bin_PROGRAMS)
 if HARDEN
 	@echo "Checking binary security..."
 	$(AM_V_at) READELF=$(READELF) OBJDUMP=$(OBJDUMP) $(top_srcdir)/contrib/devtools/security-check.py < $(bin_PROGRAMS)
 endif
 
 if ENABLE_BIP70
 %.pb.cc %.pb.h: %.proto
 	@test -f $(PROTOC)
 	$(AM_V_GEN) $(PROTOC) --cpp_out=$(@D) --proto_path=$(<D) $<
 endif
 
 if EMBEDDED_LEVELDB
 include Makefile.leveldb.include
 endif
 
 if ENABLE_TESTS
 include Makefile.test.include
 endif
 
 if ENABLE_BENCH
 include Makefile.bench.include
 endif
 
 if ENABLE_QT
 include Makefile.qt.include
 endif
 
 if ENABLE_QT_TESTS
 include Makefile.qttest.include
 endif
 
 if ENABLE_SEEDER_TESTS
 include Makefile.seedertest.include
 endif
diff --git a/src/avalanche.cpp b/src/avalanche.cpp
index 667dac539..42d694027 100644
--- a/src/avalanche.cpp
+++ b/src/avalanche.cpp
@@ -1,510 +1,553 @@
 // Copyright (c) 2018-2019 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <avalanche.h>
 
 #include <chain.h>
 #include <netmessagemaker.h>
 #include <reverse_iterator.h>
 #include <scheduler.h>
 #include <util/bitmanip.h>
 #include <validation.h>
 
 #include <tuple>
 
 /**
  * Run the avalanche event loop every 10ms.
  */
 static const int64_t AVALANCHE_TIME_STEP_MILLISECONDS = 10;
 
 // Unfortunately, the bitcoind codebase is full of global and we are kinda
 // forced into it here.
 std::unique_ptr<AvalancheProcessor> g_avalanche;
 
 bool VoteRecord::registerVote(NodeId nodeid, uint32_t error) {
     // We just got a new vote, so there is one less inflight request.
     clearInflightRequest();
 
     // We want to avoid having the same node voting twice in a quorum.
     if (!addNodeToQuorum(nodeid)) {
         return false;
     }
 
     /**
      * The result of the vote is determined from the error code. If the error
      * code is 0, there is no error and therefore the vote is yes. If there is
      * an error, we check the most significant bit to decide if the vote is a no
      * (for instance, the block is invalid) or is the vote inconclusive (for
      * instance, the queried node does not have the block yet).
      */
     votes = (votes << 1) | (error == 0);
     consider = (consider << 1) | (int32_t(error) >= 0);
 
     /**
      * We compute the number of yes and/or no votes as follow:
      *
      * votes:     1010
      * consider:  1100
      *
      * yes votes: 1000 using votes & consider
      * no votes:  0100 using ~votes & consider
      */
     bool yes = countBits(votes & consider & 0xff) > 6;
     if (!yes) {
         bool no = countBits(~votes & consider & 0xff) > 6;
         if (!no) {
             // The round is inconclusive.
             return false;
         }
     }
 
     // If the round is in agreement with previous rounds, increase confidence.
     if (isAccepted() == yes) {
         confidence += 2;
         return getConfidence() == AVALANCHE_FINALIZATION_SCORE;
     }
 
     // The round changed our state. We reset the confidence.
     confidence = yes;
     return true;
 }
 
 bool VoteRecord::addNodeToQuorum(NodeId nodeid) {
     if (nodeid == NO_NODE) {
         // Helpful for testing.
         return true;
     }
 
     // MMIX Linear Congruent Generator.
     const uint64_t r1 =
         6364136223846793005 * uint64_t(nodeid) + 1442695040888963407;
     // Fibonacci hashing.
     const uint64_t r2 = 11400714819323198485ull * (nodeid ^ seed);
     // Combine and extract hash.
     const uint16_t h = (r1 + r2) >> 48;
 
     /**
      * Check if the node is in the filter.
      */
     for (size_t i = 1; i < nodeFilter.size(); i++) {
         if (nodeFilter[(successfulVotes + i) % nodeFilter.size()] == h) {
             return false;
         }
     }
 
     /**
      * Add the node which just voted to the filter.
      */
     nodeFilter[successfulVotes % nodeFilter.size()] = h;
     successfulVotes++;
     return true;
 }
 
 bool VoteRecord::registerPoll() const {
     uint8_t count = inflight.load();
     while (count < AVALANCHE_MAX_INFLIGHT_POLL) {
         if (inflight.compare_exchange_weak(count, count + 1)) {
             return true;
         }
     }
 
     return false;
 }
 
 static bool IsWorthPolling(const CBlockIndex *pindex) {
     AssertLockHeld(cs_main);
 
     if (pindex->nStatus.isInvalid()) {
         // No point polling invalid blocks.
         return false;
     }
 
     if (IsBlockFinalized(pindex)) {
         // There is no point polling finalized block.
         return false;
     }
 
     return true;
 }
 
 AvalancheProcessor::AvalancheProcessor(CConnman *connmanIn)
     : connman(connmanIn),
       queryTimeoutDuration(
           AVALANCHE_DEFAULT_QUERY_TIMEOUT_DURATION_MILLISECONDS),
-      round(0), stopRequest(false), running(false) {}
+      round(0), stopRequest(false), running(false) {
+    // Pick a random key for the session.
+    sessionKey.MakeNewKey(true);
+}
 
 AvalancheProcessor::~AvalancheProcessor() {
     stopEventLoop();
 }
 
 bool AvalancheProcessor::addBlockToReconcile(const CBlockIndex *pindex) {
     bool isAccepted;
 
     {
         LOCK(cs_main);
         if (!IsWorthPolling(pindex)) {
             // There is no point polling this block.
             return false;
         }
 
         isAccepted = ::ChainActive().Contains(pindex);
     }
 
     return vote_records.getWriteView()
         ->insert(std::make_pair(pindex, VoteRecord(isAccepted)))
         .second;
 }
 
 bool AvalancheProcessor::isAccepted(const CBlockIndex *pindex) const {
     auto r = vote_records.getReadView();
     auto it = r->find(pindex);
     if (it == r.end()) {
         return false;
     }
 
     return it->second.isAccepted();
 }
 
 int AvalancheProcessor::getConfidence(const CBlockIndex *pindex) const {
     auto r = vote_records.getReadView();
     auto it = r->find(pindex);
     if (it == r.end()) {
         return -1;
     }
 
     return it->second.getConfidence();
 }
 
+namespace {
+/**
+ * When using TCP, we need to sign all messages as the transport layer is not
+ * secure.
+ */
+class TCPAvalancheResponse {
+    AvalancheResponse response;
+    std::array<uint8_t, 64> sig;
+
+public:
+    TCPAvalancheResponse(AvalancheResponse responseIn, const CKey &key)
+        : response(std::move(responseIn)) {
+        CHashWriter hasher(SER_GETHASH, 0);
+        hasher << response;
+        const uint256 hash = hasher.GetHash();
+
+        // Now let's sign!
+        std::vector<uint8_t> vchSig;
+        if (key.SignSchnorr(hash, vchSig)) {
+            // Schnorr sigs are 64 bytes in size.
+            assert(vchSig.size() == 64);
+            std::copy(vchSig.begin(), vchSig.end(), sig.begin());
+        } else {
+            sig.fill(0);
+        }
+    }
+
+    // serialization support
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream &s, Operation ser_action) {
+        READWRITE(response);
+        READWRITE(sig);
+    }
+};
+} // namespace
+
 void AvalancheProcessor::sendResponse(CNode *pfrom,
                                       AvalancheResponse response) const {
     connman->PushMessage(
-        pfrom, CNetMsgMaker(pfrom->GetSendVersion())
-                   .Make(NetMsgType::AVARESPONSE, std::move(response)));
+        pfrom,
+        CNetMsgMaker(pfrom->GetSendVersion())
+            .Make(NetMsgType::AVARESPONSE,
+                  TCPAvalancheResponse(std::move(response), sessionKey)));
 }
 
 bool AvalancheProcessor::registerVotes(
     NodeId nodeid, const AvalancheResponse &response,
     std::vector<AvalancheBlockUpdate> &updates) {
     {
         // Save the time at which we can query again.
         auto w = peerSet.getWriteView();
         auto it = w->find(nodeid);
         if (it != w->end()) {
             w->modify(it, [&response](Peer &p) {
                 // FIXME: This will override the time even when we received an
                 // old stale message. This should check that the message is
                 // indeed the most up to date one before updating the time.
                 p.nextRequestTime =
                     std::chrono::steady_clock::now() +
                     std::chrono::milliseconds(response.getCooldown());
             });
         }
     }
 
     std::vector<CInv> invs;
 
     {
         // Check that the query exists.
         auto w = queries.getWriteView();
         auto it = w->find(std::make_tuple(nodeid, response.getRound()));
         if (it == w.end()) {
             // NB: The request may be old, so we don't increase banscore.
             return false;
         }
 
         invs = std::move(it->invs);
         w->erase(it);
     }
 
     // Verify that the request and the vote are consistent.
     const std::vector<AvalancheVote> &votes = response.GetVotes();
     size_t size = invs.size();
     if (votes.size() != size) {
         // TODO: increase banscore for inconsistent response.
         // NB: This isn't timeout but actually node misbehaving.
         return false;
     }
 
     for (size_t i = 0; i < size; i++) {
         if (invs[i].hash != votes[i].GetHash()) {
             // TODO: increase banscore for inconsistent response.
             // NB: This isn't timeout but actually node misbehaving.
             return false;
         }
     }
 
     std::map<CBlockIndex *, AvalancheVote> responseIndex;
 
     {
         LOCK(cs_main);
         for (auto &v : votes) {
             BlockMap::iterator mi = mapBlockIndex.find(BlockHash(v.GetHash()));
             if (mi == mapBlockIndex.end()) {
                 // This should not happen, but just in case...
                 continue;
             }
 
             CBlockIndex *pindex = mi->second;
             if (!IsWorthPolling(pindex)) {
                 // There is no point polling this block.
                 continue;
             }
 
             responseIndex.insert(std::make_pair(pindex, v));
         }
     }
 
     {
         // Register votes.
         auto w = vote_records.getWriteView();
         for (auto &p : responseIndex) {
             CBlockIndex *pindex = p.first;
             const AvalancheVote &v = p.second;
 
             auto it = w->find(pindex);
             if (it == w.end()) {
                 // We are not voting on that item anymore.
                 continue;
             }
 
             auto &vr = it->second;
             if (!vr.registerVote(nodeid, v.GetError())) {
                 // This vote did not provide any extra information, move on.
                 continue;
             }
 
             if (!vr.hasFinalized()) {
                 // This item has note been finalized, so we have nothing more to
                 // do.
                 updates.emplace_back(
                     pindex, vr.isAccepted()
                                 ? AvalancheBlockUpdate::Status::Accepted
                                 : AvalancheBlockUpdate::Status::Rejected);
                 continue;
             }
 
             // We just finalized a vote. If it is valid, then let the caller
             // know. Either way, remove the item from the map.
             updates.emplace_back(pindex,
                                  vr.isAccepted()
                                      ? AvalancheBlockUpdate::Status::Finalized
                                      : AvalancheBlockUpdate::Status::Invalid);
             w->erase(it);
         }
     }
 
     return true;
 }
 
 bool AvalancheProcessor::addPeer(NodeId nodeid, int64_t score) {
     return peerSet.getWriteView()
         ->insert({nodeid, score, std::chrono::steady_clock::now()})
         .second;
 }
 
 bool AvalancheProcessor::startEventLoop(CScheduler &scheduler) {
     LOCK(cs_running);
     if (running) {
         // Do not start the event loop twice.
         return false;
     }
 
     running = true;
 
     // Start the event loop.
     scheduler.scheduleEvery(
         [this]() -> bool {
             runEventLoop();
             if (!stopRequest) {
                 return true;
             }
 
             LOCK(cs_running);
             running = false;
 
             cond_running.notify_all();
 
             // A stop request was made.
             return false;
         },
         AVALANCHE_TIME_STEP_MILLISECONDS);
 
     return true;
 }
 
 bool AvalancheProcessor::stopEventLoop() {
     WAIT_LOCK(cs_running, lock);
     if (!running) {
         return false;
     }
 
     // Request avalanche to stop.
     stopRequest = true;
 
     // Wait for avalanche to stop.
     cond_running.wait(lock, [this]() EXCLUSIVE_LOCKS_REQUIRED(cs_running) {
         return !running;
     });
 
     stopRequest = false;
     return true;
 }
 
 std::vector<CInv> AvalancheProcessor::getInvsForNextPoll(bool forPoll) const {
     std::vector<CInv> invs;
 
     auto r = vote_records.getReadView();
     for (const std::pair<const CBlockIndex *const, VoteRecord> &p :
          reverse_iterate(r)) {
         const CBlockIndex *pindex = p.first;
 
         {
             LOCK(cs_main);
             if (!IsWorthPolling(pindex)) {
                 // Obviously do not poll if the block is not worth polling.
                 continue;
             }
         }
 
         // Check if we can run poll.
         const bool shouldPoll =
             forPoll ? p.second.registerPoll() : p.second.shouldPoll();
         if (!shouldPoll) {
             continue;
         }
 
         // We don't have a decision, we need more votes.
         invs.emplace_back(MSG_BLOCK, pindex->GetBlockHash());
         if (invs.size() >= AVALANCHE_MAX_ELEMENT_POLL) {
             // Make sure we do not produce more invs than specified by the
             // protocol.
             return invs;
         }
     }
 
     return invs;
 }
 
 NodeId AvalancheProcessor::getSuitableNodeToQuery() {
     auto r = peerSet.getReadView();
     auto it = r->get<next_request_time>().begin();
     if (it == r->get<next_request_time>().end()) {
         return NO_NODE;
     }
 
     if (it->nextRequestTime <= std::chrono::steady_clock::now()) {
         return it->nodeid;
     }
 
     return NO_NODE;
 }
 
 void AvalancheProcessor::clearTimedoutRequests() {
     auto now = std::chrono::steady_clock::now();
     std::map<CInv, uint8_t> timedout_items{};
 
     {
         // Clear expired requests.
         auto w = queries.getWriteView();
         auto it = w->get<query_timeout>().begin();
         while (it != w->get<query_timeout>().end() && it->timeout < now) {
             for (auto &i : it->invs) {
                 timedout_items[i]++;
             }
 
             w->get<query_timeout>().erase(it++);
         }
     }
 
     if (timedout_items.empty()) {
         return;
     }
 
     // In flight request accounting.
     for (const auto &p : timedout_items) {
         const CInv &inv = p.first;
         assert(inv.type == MSG_BLOCK);
 
         CBlockIndex *pindex;
 
         {
             LOCK(cs_main);
             BlockMap::iterator mi = mapBlockIndex.find(BlockHash(inv.hash));
             if (mi == mapBlockIndex.end()) {
                 continue;
             }
 
             pindex = mi->second;
         }
 
         auto w = vote_records.getWriteView();
         auto it = w->find(pindex);
         if (it == w.end()) {
             continue;
         }
 
         it->second.clearInflightRequest(p.second);
     }
 }
 
 void AvalancheProcessor::runEventLoop() {
     // First things first, check if we have requests that timed out and clear
     // them.
     clearTimedoutRequests();
 
     while (true) {
         NodeId nodeid = getSuitableNodeToQuery();
         if (nodeid == NO_NODE) {
             return;
         }
 
         /**
          * If we lost contact to that node, then we remove it from nodeids, but
          * never add the request to queries, which ensures bad nodes get cleaned
          * up over time.
          */
         std::vector<CInv> invs;
         bool hasSent = connman->ForNode(nodeid, [this, &invs](CNode *pnode) {
             invs = getInvsForNextPoll();
             if (invs.empty()) {
                 return false;
             }
 
             uint64_t current_round = round++;
 
             {
                 // Compute the time at which this requests times out.
                 auto timeout =
                     std::chrono::steady_clock::now() + queryTimeoutDuration;
                 // Register the query.
                 queries.getWriteView()->insert(
                     {pnode->GetId(), current_round, timeout, invs});
                 // Set the timeout.
                 auto w = peerSet.getWriteView();
                 auto it = w->find(pnode->GetId());
                 if (it != w->end()) {
                     w->modify(it, [&timeout](Peer &p) {
                         p.nextRequestTime = timeout;
                     });
                 }
             }
 
             // Send the query to the node.
             connman->PushMessage(
                 pnode,
                 CNetMsgMaker(pnode->GetSendVersion())
                     .Make(NetMsgType::AVAPOLL,
                           AvalanchePoll(current_round, std::move(invs))));
             return true;
         });
 
         // Success!
         if (hasSent || invs.empty()) {
             return;
         }
 
         // This node is obsolete, delete it.
         peerSet.getWriteView()->erase(nodeid);
     }
 }
diff --git a/src/avalanche.h b/src/avalanche.h
index e36f10ece..4cf28c19e 100644
--- a/src/avalanche.h
+++ b/src/avalanche.h
@@ -1,370 +1,375 @@
 // Copyright (c) 2018-2019 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_AVALANCHE_H
 #define BITCOIN_AVALANCHE_H
 
 #include <blockindexworkcomparator.h>
+#include <key.h>
 #include <net.h>
 #include <protocol.h> // for CInv
 #include <rwcollection.h>
 #include <serialize.h>
 #include <uint256.h>
 
 #include <boost/multi_index/composite_key.hpp>
 #include <boost/multi_index/hashed_index.hpp>
 #include <boost/multi_index/member.hpp>
 #include <boost/multi_index/ordered_index.hpp>
 #include <boost/multi_index_container.hpp>
 
 #include <atomic>
 #include <chrono>
 #include <condition_variable>
 #include <cstdint>
 #include <vector>
 
 class Config;
 class CBlockIndex;
 class CScheduler;
 
 namespace {
 /**
  * Is avalanche enabled by default.
  */
 static const bool AVALANCHE_DEFAULT_ENABLED = false;
 
 /**
  * Finalization score.
  */
 static const int AVALANCHE_FINALIZATION_SCORE = 128;
 
 /**
  * Maximum item that can be polled at once.
  */
 static const size_t AVALANCHE_MAX_ELEMENT_POLL = 16;
 /**
  * Avalanche default cooldown in milliseconds.
  */
 static const size_t AVALANCHE_DEFAULT_COOLDOWN = 100;
 /**
  * How long before we consider that a query timed out.
  */
 static const int AVALANCHE_DEFAULT_QUERY_TIMEOUT_DURATION_MILLISECONDS = 10000;
 
 /**
  * How many inflight requests can exist for one item.
  */
 static const int AVALANCHE_MAX_INFLIGHT_POLL = 10;
 
 /**
  * Special NodeId that represent no node.
  */
 static const NodeId NO_NODE = -1;
 } // namespace
 
 /**
  * Vote history.
  */
 struct VoteRecord {
 private:
     // confidence's LSB bit is the result. Higher bits are actual confidence
     // score.
     uint16_t confidence = 0;
 
     // Historical record of votes.
     uint8_t votes = 0;
     // Each bit indicate if the vote is to be considered.
     uint8_t consider = 0;
     // How many in flight requests exists for this element.
     mutable std::atomic<uint8_t> inflight{0};
 
     // Seed for pseudorandom operations.
     const uint32_t seed = 0;
 
     // Track how many successful votes occured.
     uint32_t successfulVotes = 0;
 
     // Track the nodes which are part of the quorum.
     std::array<uint16_t, 8> nodeFilter{{0, 0, 0, 0, 0, 0, 0, 0}};
 
 public:
     VoteRecord(bool accepted) : confidence(accepted) {}
 
     /**
      * Copy semantic
      */
     VoteRecord(const VoteRecord &other)
         : confidence(other.confidence), votes(other.votes),
           consider(other.consider), inflight(other.inflight.load()),
           successfulVotes(other.successfulVotes), nodeFilter(other.nodeFilter) {
     }
 
     /**
      * Vote accounting facilities.
      */
     bool isAccepted() const { return confidence & 0x01; }
 
     uint16_t getConfidence() const { return confidence >> 1; }
     bool hasFinalized() const {
         return getConfidence() >= AVALANCHE_FINALIZATION_SCORE;
     }
 
     /**
      * Register a new vote for an item and update confidence accordingly.
      * Returns true if the acceptance or finalization state changed.
      */
     bool registerVote(NodeId nodeid, uint32_t error);
 
     /**
      * Register that a request is being made regarding that item.
      * The method is made const so that it can be accessed via a read only view
      * of vote_records. It's not a problem as it is made thread safe.
      */
     bool registerPoll() const;
 
     /**
      * Return if this item is in condition to be polled at the moment.
      */
     bool shouldPoll() const { return inflight < AVALANCHE_MAX_INFLIGHT_POLL; }
 
     /**
      * Clear `count` inflight requests.
      */
     void clearInflightRequest(uint8_t count = 1) { inflight -= count; }
 
 private:
     /**
      * Add the node to the quorum.
      * Returns true if the node was added, false if the node already was in the
      * quorum.
      */
     bool addNodeToQuorum(NodeId nodeid);
 };
 
 class AvalancheVote {
     uint32_t error;
     uint256 hash;
 
 public:
     AvalancheVote() : error(-1), hash() {}
     AvalancheVote(uint32_t errorIn, uint256 hashIn)
         : error(errorIn), hash(hashIn) {}
 
     const uint256 &GetHash() const { return hash; }
     uint32_t GetError() const { return error; }
 
     // serialization support
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(error);
         READWRITE(hash);
     }
 };
 
 class AvalancheResponse {
     uint64_t round;
     uint32_t cooldown;
     std::vector<AvalancheVote> votes;
 
 public:
     AvalancheResponse(uint64_t roundIn, uint32_t cooldownIn,
                       std::vector<AvalancheVote> votesIn)
         : round(roundIn), cooldown(cooldownIn), votes(votesIn) {}
 
     uint64_t getRound() const { return round; }
     uint32_t getCooldown() const { return cooldown; }
     const std::vector<AvalancheVote> &GetVotes() const { return votes; }
 
     // serialization support
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(round);
         READWRITE(cooldown);
         READWRITE(votes);
     }
 };
 
 class AvalanchePoll {
     uint64_t round;
     std::vector<CInv> invs;
 
 public:
     AvalanchePoll(uint64_t roundIn, std::vector<CInv> invsIn)
         : round(roundIn), invs(invsIn) {}
 
     const std::vector<CInv> &GetInvs() const { return invs; }
 
     // serialization support
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(round);
         READWRITE(invs);
     }
 };
 
 class AvalancheBlockUpdate {
     union {
         CBlockIndex *pindex;
         uintptr_t raw;
     };
 
     static const size_t STATUS_BITS = 2;
     static const uintptr_t MASK = (1 << STATUS_BITS) - 1;
 
     static_assert(
         alignof(CBlockIndex) >= (1 << STATUS_BITS),
         "CBlockIndex alignement doesn't allow for Status to be stored.");
 
 public:
     enum Status : uint8_t {
         Invalid,
         Rejected,
         Accepted,
         Finalized,
     };
 
     AvalancheBlockUpdate(CBlockIndex *pindexIn, Status statusIn)
         : pindex(pindexIn) {
         raw |= statusIn;
     }
 
     Status getStatus() const { return Status(raw & MASK); }
 
     CBlockIndex *getBlockIndex() {
         return reinterpret_cast<CBlockIndex *>(raw & ~MASK);
     }
 
     const CBlockIndex *getBlockIndex() const {
         return const_cast<AvalancheBlockUpdate *>(this)->getBlockIndex();
     }
 };
 
 typedef std::map<const CBlockIndex *, VoteRecord, CBlockIndexWorkComparator>
     BlockVoteMap;
 
 struct next_request_time {};
 struct query_timeout {};
 
 class AvalancheProcessor {
 private:
     CConnman *connman;
     std::chrono::milliseconds queryTimeoutDuration;
 
     /**
      * Blocks to run avalanche on.
      */
     RWCollection<BlockVoteMap> vote_records;
 
     /**
      * Keep track of peers and queries sent.
      */
     std::atomic<uint64_t> round;
 
     typedef std::chrono::time_point<std::chrono::steady_clock> TimePoint;
 
     struct Peer {
         NodeId nodeid;
         int64_t score;
 
         TimePoint nextRequestTime;
     };
 
     typedef boost::multi_index_container<
         Peer, boost::multi_index::indexed_by<
                   // index by nodeid
                   boost::multi_index::hashed_unique<
                       boost::multi_index::member<Peer, NodeId, &Peer::nodeid>>,
                   // sorted by nextRequestTime
                   boost::multi_index::ordered_non_unique<
                       boost::multi_index::tag<next_request_time>,
                       boost::multi_index::member<Peer, TimePoint,
                                                  &Peer::nextRequestTime>>>>
         PeerSet;
 
     RWCollection<PeerSet> peerSet;
 
     struct Query {
         NodeId nodeid;
         uint64_t round;
         TimePoint timeout;
 
         /**
          * We declare this as mutable so it can be modified in the multi_index.
          * This is ok because we do not use this field to index in anyway.
          *
          * /!\ Do not use any mutable field as index.
          */
         mutable std::vector<CInv> invs;
     };
 
     typedef boost::multi_index_container<
         Query,
         boost::multi_index::indexed_by<
             // index by nodeid/round
             boost::multi_index::ordered_unique<
                 boost::multi_index::composite_key<
                     Query,
                     boost::multi_index::member<Query, NodeId, &Query::nodeid>,
                     boost::multi_index::member<Query, uint64_t,
                                                &Query::round>>>,
             // sorted by timeout
             boost::multi_index::ordered_non_unique<
                 boost::multi_index::tag<query_timeout>,
                 boost::multi_index::member<Query, TimePoint, &Query::timeout>>>>
         QuerySet;
 
     RWCollection<QuerySet> queries;
 
     /**
      * Start stop machinery.
      */
     std::atomic<bool> stopRequest;
     bool running GUARDED_BY(cs_running);
 
     Mutex cs_running;
     std::condition_variable cond_running;
 
+    CKey sessionKey;
+
 public:
     AvalancheProcessor(CConnman *connmanIn);
     ~AvalancheProcessor();
 
     void setQueryTimeoutDuration(std::chrono::milliseconds d) {
         queryTimeoutDuration = d;
     }
 
     bool addBlockToReconcile(const CBlockIndex *pindex);
     bool isAccepted(const CBlockIndex *pindex) const;
     int getConfidence(const CBlockIndex *pindex) const;
 
     void sendResponse(CNode *pfrom, AvalancheResponse response) const;
 
     bool registerVotes(NodeId nodeid, const AvalancheResponse &response,
                        std::vector<AvalancheBlockUpdate> &updates);
 
     bool addPeer(NodeId nodeid, int64_t score);
 
+    CPubKey getSessionPubKey() const { return sessionKey.GetPubKey(); }
+
     bool startEventLoop(CScheduler &scheduler);
     bool stopEventLoop();
 
 private:
     void runEventLoop();
     void clearTimedoutRequests();
     std::vector<CInv> getInvsForNextPoll(bool forPoll = true) const;
     NodeId getSuitableNodeToQuery();
 
     friend struct AvalancheTest;
 };
 
 /**
  * Global avalanche instance.
  */
 extern std::unique_ptr<AvalancheProcessor> g_avalanche;
 
 #endif // BITCOIN_AVALANCHE_H
diff --git a/src/pubkey.cpp b/src/pubkey.cpp
index 9a502c690..e0fcc679e 100644
--- a/src/pubkey.cpp
+++ b/src/pubkey.cpp
@@ -1,354 +1,354 @@
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Copyright (c) 2017 The Zcash developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <pubkey.h>
 
 #include <secp256k1.h>
 #include <secp256k1_recovery.h>
 #include <secp256k1_schnorr.h>
 
 namespace {
 /* Global secp256k1_context object used for verification. */
 secp256k1_context *secp256k1_context_verify = nullptr;
 } // namespace
 
 /**
  * This function is taken from the libsecp256k1 distribution and implements DER
  * parsing for ECDSA signatures, while supporting an arbitrary subset of format
  * violations.
  *
  * Supported violations include negative integers, excessive padding, garbage at
  * the end, and overly long length descriptors. This is safe to use in Bitcoin
  * because since the activation of BIP66, signatures are verified to be strict
  * DER before being passed to this module, and we know it supports all
  * violations present in the blockchain before that point.
  */
 static int ecdsa_signature_parse_der_lax(const secp256k1_context *ctx,
                                          secp256k1_ecdsa_signature *sig,
                                          const uint8_t *input,
                                          size_t inputlen) {
     size_t rpos, rlen, spos, slen;
     size_t pos = 0;
     size_t lenbyte;
     uint8_t tmpsig[64] = {0};
     int overflow = 0;
 
     /* Hack to initialize sig with a correctly-parsed but invalid signature. */
     secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig);
 
     /* Sequence tag byte */
     if (pos == inputlen || input[pos] != 0x30) {
         return 0;
     }
     pos++;
 
     /* Sequence length bytes */
     if (pos == inputlen) {
         return 0;
     }
     lenbyte = input[pos++];
     if (lenbyte & 0x80) {
         lenbyte -= 0x80;
         if (lenbyte > inputlen - pos) {
             return 0;
         }
         pos += lenbyte;
     }
 
     /* Integer tag byte for R */
     if (pos == inputlen || input[pos] != 0x02) {
         return 0;
     }
     pos++;
 
     /* Integer length for R */
     if (pos == inputlen) {
         return 0;
     }
     lenbyte = input[pos++];
     if (lenbyte & 0x80) {
         lenbyte -= 0x80;
         if (lenbyte > inputlen - pos) {
             return 0;
         }
         while (lenbyte > 0 && input[pos] == 0) {
             pos++;
             lenbyte--;
         }
         static_assert(sizeof(size_t) >= 4, "size_t too small");
         if (lenbyte >= 4) {
             return 0;
         }
         rlen = 0;
         while (lenbyte > 0) {
             rlen = (rlen << 8) + input[pos];
             pos++;
             lenbyte--;
         }
     } else {
         rlen = lenbyte;
     }
     if (rlen > inputlen - pos) {
         return 0;
     }
     rpos = pos;
     pos += rlen;
 
     /* Integer tag byte for S */
     if (pos == inputlen || input[pos] != 0x02) {
         return 0;
     }
     pos++;
 
     /* Integer length for S */
     if (pos == inputlen) {
         return 0;
     }
     lenbyte = input[pos++];
     if (lenbyte & 0x80) {
         lenbyte -= 0x80;
         if (lenbyte > inputlen - pos) {
             return 0;
         }
         while (lenbyte > 0 && input[pos] == 0) {
             pos++;
             lenbyte--;
         }
         static_assert(sizeof(size_t) >= 4, "size_t too small");
         if (lenbyte >= 4) {
             return 0;
         }
         slen = 0;
         while (lenbyte > 0) {
             slen = (slen << 8) + input[pos];
             pos++;
             lenbyte--;
         }
     } else {
         slen = lenbyte;
     }
     if (slen > inputlen - pos) {
         return 0;
     }
     spos = pos;
 
     /* Ignore leading zeroes in R */
     while (rlen > 0 && input[rpos] == 0) {
         rlen--;
         rpos++;
     }
     /* Copy R value */
     if (rlen > 32) {
         overflow = 1;
     } else {
         memcpy(tmpsig + 32 - rlen, input + rpos, rlen);
     }
 
     /* Ignore leading zeroes in S */
     while (slen > 0 && input[spos] == 0) {
         slen--;
         spos++;
     }
     /* Copy S value */
     if (slen > 32) {
         overflow = 1;
     } else {
         memcpy(tmpsig + 64 - slen, input + spos, slen);
     }
 
     if (!overflow) {
         overflow = !secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig);
     }
     if (overflow) {
         /* Overwrite the result again with a correctly-parsed but invalid
            signature if parsing failed. */
         memset(tmpsig, 0, 64);
         secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig);
     }
     return 1;
 }
 
 bool CPubKey::VerifyECDSA(const uint256 &hash,
                           const std::vector<uint8_t> &vchSig) const {
     if (!IsValid()) {
         return false;
     }
 
     secp256k1_pubkey pubkey;
     secp256k1_ecdsa_signature sig;
     if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, vch,
                                    size())) {
         return false;
     }
     if (!ecdsa_signature_parse_der_lax(secp256k1_context_verify, &sig,
                                        vchSig.data(), vchSig.size())) {
         return false;
     }
     /**
      * libsecp256k1's ECDSA verification requires lower-S signatures, which have
      * not historically been enforced in Bitcoin, so normalize them first.
      */
     secp256k1_ecdsa_signature_normalize(secp256k1_context_verify, &sig, &sig);
     return secp256k1_ecdsa_verify(secp256k1_context_verify, &sig, hash.begin(),
                                   &pubkey);
 }
 
 bool CPubKey::VerifySchnorr(const uint256 &hash,
                             const std::vector<uint8_t> &vchSig) const {
     if (!IsValid()) {
         return false;
     }
 
     if (vchSig.size() != 64) {
         return false;
     }
 
     secp256k1_pubkey pubkey;
     if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey,
                                    &(*this)[0], size())) {
         return false;
     }
 
-    return secp256k1_schnorr_verify(secp256k1_context_verify, &vchSig[0],
+    return secp256k1_schnorr_verify(secp256k1_context_verify, vchSig.data(),
                                     hash.begin(), &pubkey);
 }
 
 bool CPubKey::RecoverCompact(const uint256 &hash,
                              const std::vector<uint8_t> &vchSig) {
     if (vchSig.size() != COMPACT_SIGNATURE_SIZE) {
         return false;
     }
 
     int recid = (vchSig[0] - 27) & 3;
     bool fComp = ((vchSig[0] - 27) & 4) != 0;
     secp256k1_pubkey pubkey;
     secp256k1_ecdsa_recoverable_signature sig;
     if (!secp256k1_ecdsa_recoverable_signature_parse_compact(
             secp256k1_context_verify, &sig, &vchSig[1], recid)) {
         return false;
     }
     if (!secp256k1_ecdsa_recover(secp256k1_context_verify, &pubkey, &sig,
                                  hash.begin())) {
         return false;
     }
     uint8_t pub[PUBLIC_KEY_SIZE];
     size_t publen = PUBLIC_KEY_SIZE;
     secp256k1_ec_pubkey_serialize(
         secp256k1_context_verify, pub, &publen, &pubkey,
         fComp ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED);
     Set(pub, pub + publen);
     return true;
 }
 
 bool CPubKey::IsFullyValid() const {
     if (!IsValid()) {
         return false;
     }
     secp256k1_pubkey pubkey;
     return secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, vch,
                                      size());
 }
 
 bool CPubKey::Decompress() {
     if (!IsValid()) {
         return false;
     }
     secp256k1_pubkey pubkey;
     if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, vch,
                                    size())) {
         return false;
     }
     uint8_t pub[PUBLIC_KEY_SIZE];
     size_t publen = PUBLIC_KEY_SIZE;
     secp256k1_ec_pubkey_serialize(secp256k1_context_verify, pub, &publen,
                                   &pubkey, SECP256K1_EC_UNCOMPRESSED);
     Set(pub, pub + publen);
     return true;
 }
 
 bool CPubKey::Derive(CPubKey &pubkeyChild, ChainCode &ccChild,
                      unsigned int nChild, const ChainCode &cc) const {
     assert(IsValid());
     assert((nChild >> 31) == 0);
     assert(size() == COMPRESSED_PUBLIC_KEY_SIZE);
     uint8_t out[64];
     BIP32Hash(cc, nChild, *begin(), begin() + 1, out);
     memcpy(ccChild.begin(), out + 32, 32);
     secp256k1_pubkey pubkey;
     if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, vch,
                                    size())) {
         return false;
     }
     if (!secp256k1_ec_pubkey_tweak_add(secp256k1_context_verify, &pubkey,
                                        out)) {
         return false;
     }
     uint8_t pub[COMPRESSED_PUBLIC_KEY_SIZE];
     size_t publen = COMPRESSED_PUBLIC_KEY_SIZE;
     secp256k1_ec_pubkey_serialize(secp256k1_context_verify, pub, &publen,
                                   &pubkey, SECP256K1_EC_COMPRESSED);
     pubkeyChild.Set(pub, pub + publen);
     return true;
 }
 
 void CExtPubKey::Encode(uint8_t code[BIP32_EXTKEY_SIZE]) const {
     code[0] = nDepth;
     memcpy(code + 1, vchFingerprint, 4);
     code[5] = (nChild >> 24) & 0xFF;
     code[6] = (nChild >> 16) & 0xFF;
     code[7] = (nChild >> 8) & 0xFF;
     code[8] = (nChild >> 0) & 0xFF;
     memcpy(code + 9, chaincode.begin(), 32);
     assert(pubkey.size() == CPubKey::COMPRESSED_PUBLIC_KEY_SIZE);
     memcpy(code + 41, pubkey.begin(), CPubKey::COMPRESSED_PUBLIC_KEY_SIZE);
 }
 
 void CExtPubKey::Decode(const uint8_t code[BIP32_EXTKEY_SIZE]) {
     nDepth = code[0];
     memcpy(vchFingerprint, code + 1, 4);
     nChild = (code[5] << 24) | (code[6] << 16) | (code[7] << 8) | code[8];
     memcpy(chaincode.begin(), code + 9, 32);
     pubkey.Set(code + 41, code + BIP32_EXTKEY_SIZE);
 }
 
 bool CExtPubKey::Derive(CExtPubKey &out, unsigned int _nChild) const {
     out.nDepth = nDepth + 1;
     CKeyID id = pubkey.GetID();
     memcpy(&out.vchFingerprint[0], &id, 4);
     out.nChild = _nChild;
     return pubkey.Derive(out.pubkey, out.chaincode, _nChild, chaincode);
 }
 
 bool CPubKey::CheckLowS(
     const boost::sliced_range<const std::vector<uint8_t>> &vchSig) {
     secp256k1_ecdsa_signature sig;
     if (!ecdsa_signature_parse_der_lax(secp256k1_context_verify, &sig,
                                        &vchSig.front(), vchSig.size())) {
         return false;
     }
     return (!secp256k1_ecdsa_signature_normalize(secp256k1_context_verify,
                                                  nullptr, &sig));
 }
 
 /* static */ int ECCVerifyHandle::refcount = 0;
 
 ECCVerifyHandle::ECCVerifyHandle() {
     if (refcount == 0) {
         assert(secp256k1_context_verify == nullptr);
         secp256k1_context_verify =
             secp256k1_context_create(SECP256K1_CONTEXT_VERIFY);
         assert(secp256k1_context_verify != nullptr);
     }
     refcount++;
 }
 
 ECCVerifyHandle::~ECCVerifyHandle() {
     refcount--;
     if (refcount == 0) {
         assert(secp256k1_context_verify != nullptr);
         secp256k1_context_destroy(secp256k1_context_verify);
         secp256k1_context_verify = nullptr;
     }
 }
diff --git a/src/rpc/avalanche.cpp b/src/rpc/avalanche.cpp
new file mode 100644
index 000000000..15a48f2ec
--- /dev/null
+++ b/src/rpc/avalanche.cpp
@@ -0,0 +1,45 @@
+// Copyright (c) 2020 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <avalanche.h>
+#include <config.h>
+#include <key_io.h>
+#include <rpc/server.h>
+#include <rpc/util.h>
+#include <util/strencodings.h>
+
+#include <univalue.h>
+
+static UniValue getavalanchekey(const Config &config,
+                                const JSONRPCRequest &request) {
+    if (request.fHelp || request.params.size() != 0) {
+        throw std::runtime_error(
+            RPCHelpMan{"getavalanchekey",
+                       "\nReturns the key used to sign avalanche messages.\n",
+                       {}}
+                .ToString() +
+            "\nExamples:\n" + HelpExampleRpc("getavalanchekey", ""));
+    }
+
+    if (!g_avalanche) {
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
+                           "Avalanche is not initialized");
+    }
+
+    return HexStr(g_avalanche->getSessionPubKey());
+}
+
+// clang-format off
+static const ContextFreeRPCCommand commands[] = {
+    //  category            name                      actor (function)        argNames
+    //  ------------------- ------------------------  ----------------------  ----------
+    { "avalanche",          "getavalanchekey",        getavalanchekey,        {}},
+};
+// clang-format on
+
+void RegisterAvalancheRPCCommands(CRPCTable &t) {
+    for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++) {
+        t.appendCommand(commands[vcidx].name, &commands[vcidx]);
+    }
+}
diff --git a/src/rpc/register.h b/src/rpc/register.h
index 2b835dbd7..a5e7d4cb4 100644
--- a/src/rpc/register.h
+++ b/src/rpc/register.h
@@ -1,50 +1,53 @@
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_RPC_REGISTER_H
 #define BITCOIN_RPC_REGISTER_H
 
 /** These are in one header file to avoid creating tons of single-function
  * headers for everything under src/rpc/ */
 class CRPCTable;
 class RPCServer;
 
 /** Register block chain RPC commands */
 void RegisterBlockchainRPCCommands(CRPCTable &tableRPC);
 /** Register P2P networking RPC commands */
 void RegisterNetRPCCommands(CRPCTable &tableRPC);
 /** Register miscellaneous RPC commands */
 void RegisterMiscRPCCommands(CRPCTable &tableRPC);
 /** Register mining RPC commands */
 void RegisterMiningRPCCommands(CRPCTable &tableRPC);
 /** Register raw transaction RPC commands */
 void RegisterRawTransactionRPCCommands(CRPCTable &tableRPC);
 /** Register ABC RPC commands */
 void RegisterABCRPCCommands(CRPCTable &tableRPC);
+/** Register Avalanche RPC commands */
+void RegisterAvalancheRPCCommands(CRPCTable &tableRPC);
 
 /**
  * Register all context-free (legacy) RPC commands, except for wallet and dump
  * RPC commands.
  */
 static inline void RegisterAllContextFreeRPCCommands(CRPCTable &t) {
     RegisterBlockchainRPCCommands(t);
     RegisterNetRPCCommands(t);
     RegisterMiscRPCCommands(t);
     RegisterMiningRPCCommands(t);
     RegisterRawTransactionRPCCommands(t);
     RegisterABCRPCCommands(t);
+    RegisterAvalancheRPCCommands(t);
 }
 
 /**
  * Register all context-sensitive RPC commands.
  */
 static inline void RegisterAllRPCCommands(const Config &config,
                                           RPCServer &rpcServer,
                                           CRPCTable &rpcTable) {
     // TODO Register context-sensitive RPC commands using rpcServer
 
     RegisterAllContextFreeRPCCommands(rpcTable);
 }
 
 #endif // BITCOIN_RPC_REGISTER_H
diff --git a/test/functional/abc-p2p-avalanche.py b/test/functional/abc-p2p-avalanche.py
index 215d6e143..f71a0d63e 100755
--- a/test/functional/abc-p2p-avalanche.py
+++ b/test/functional/abc-p2p-avalanche.py
@@ -1,131 +1,141 @@
 #!/usr/bin/env python3
 # Copyright (c) 2018 The Bitcoin developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test the resolution of forks via avalanche."""
 import random
 
-from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import assert_equal, wait_until
 from test_framework.mininode import P2PInterface, mininode_lock
 from test_framework.messages import AvalancheVote, CInv, msg_avapoll
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal, wait_until
+from test_framework import schnorr
 
 
 BLOCK_ACCEPTED = 0
 BLOCK_REJECTED = 1
 BLOCK_UNKNOWN = -1
 
 
 class TestNode(P2PInterface):
 
     def __init__(self):
         self.last_avaresponse = None
         super().__init__()
 
     def on_avaresponse(self, message):
         self.last_avaresponse = message.response
 
     def send_poll(self, hashes):
         msg = msg_avapoll()
         for h in hashes:
             msg.poll.invs.append(CInv(2, h))
         self.send_message(msg)
 
     def wait_for_avaresponse(self, timeout=10):
         self.sync_with_ping()
 
         def test_function():
             m = self.last_message.get("avaresponse")
             return m is not None and m != self.last_avaresponse
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
 
 class AvalancheTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 1
         self.extra_args = [['-enableavalanche=1', '-avacooldown=0']]
 
     def run_test(self):
         node = self.nodes[0]
 
         # Create a fake node and connect it to our real node.
         poll_node = TestNode()
         node.add_p2p_connection(poll_node)
         poll_node.wait_for_verack()
         poll_node.sync_with_ping()
 
         # Generate many block and poll for them.
         address = node.get_deterministic_priv_key().address
         node.generatetoaddress(100, address)
 
+        # Get the key so we can verify signatures.
+        avakey = bytes.fromhex(node.getavalanchekey())
+
         self.log.info("Poll for the chain tip...")
         best_block_hash = int(node.getbestblockhash(), 16)
         poll_node.send_poll([best_block_hash])
         poll_node.wait_for_avaresponse()
 
         def assert_response(response, expected):
-            votes = response.votes
+            r = response.response
+            assert_equal(r.cooldown, 0)
+
+            # Verify signature.
+            assert schnorr.verify(response.sig, avakey, r.get_hash())
+
+            votes = r.votes
             self.log.info("response: {}".format(repr(response)))
             assert_equal(len(votes), len(expected))
             for i in range(0, len(votes)):
                 assert_equal(repr(votes[i]), repr(expected[i]))
 
         assert_response(poll_node.last_avaresponse, [
                         AvalancheVote(BLOCK_ACCEPTED, best_block_hash)])
 
         self.log.info("Poll for a selection of blocks...")
         various_block_hashes = [
             int(node.getblockhash(0), 16),
             int(node.getblockhash(1), 16),
             int(node.getblockhash(10), 16),
             int(node.getblockhash(25), 16),
             int(node.getblockhash(42), 16),
             int(node.getblockhash(96), 16),
             int(node.getblockhash(99), 16),
             int(node.getblockhash(100), 16),
         ]
 
         poll_node.send_poll(various_block_hashes)
         poll_node.wait_for_avaresponse()
         assert_response(poll_node.last_avaresponse,
                         [AvalancheVote(BLOCK_ACCEPTED, h) for h in various_block_hashes])
 
         self.log.info(
             "Poll for a selection of blocks, but some are now invalid...")
         invalidated_block = node.getblockhash(75)
         node.invalidateblock(invalidated_block)
         # We need to send the coin to a new address in order to make sure we do
         # not regenerate the same block.
         node.generatetoaddress(
             30, 'bchreg:pqv2r67sgz3qumufap3h2uuj0zfmnzuv8v7ej0fffv')
         node.reconsiderblock(invalidated_block)
 
         poll_node.send_poll(various_block_hashes)
         poll_node.wait_for_avaresponse()
         assert_response(poll_node.last_avaresponse,
                         [AvalancheVote(BLOCK_ACCEPTED, h) for h in various_block_hashes[:5]] +
                         [AvalancheVote(BLOCK_REJECTED, h) for h in various_block_hashes[-3:]])
 
         self.log.info("Poll for unknown blocks...")
         various_block_hashes = [
             int(node.getblockhash(0), 16),
             int(node.getblockhash(25), 16),
             int(node.getblockhash(42), 16),
             various_block_hashes[5],
             various_block_hashes[6],
             various_block_hashes[7],
             random.randrange(1 << 255, (1 << 256) - 1),
             random.randrange(1 << 255, (1 << 256) - 1),
             random.randrange(1 << 255, (1 << 256) - 1),
         ]
         poll_node.send_poll(various_block_hashes)
         poll_node.wait_for_avaresponse()
         assert_response(poll_node.last_avaresponse,
                         [AvalancheVote(BLOCK_ACCEPTED, h) for h in various_block_hashes[:3]] +
                         [AvalancheVote(BLOCK_REJECTED, h) for h in various_block_hashes[3:6]] +
                         [AvalancheVote(BLOCK_UNKNOWN, h) for h in various_block_hashes[-3:]])
 
 
 if __name__ == '__main__':
     AvalancheTest().main()
diff --git a/test/functional/rpc_help.py b/test/functional/rpc_help.py
index c4436e074..2cb846e17 100755
--- a/test/functional/rpc_help.py
+++ b/test/functional/rpc_help.py
@@ -1,44 +1,44 @@
 #!/usr/bin/env python3
 # Copyright (c) 2018 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test RPC help output."""
 
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import assert_equal, assert_raises_rpc_error
 
 
 class HelpRpcTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
 
     def run_test(self):
         node = self.nodes[0]
 
         # wrong argument count
         assert_raises_rpc_error(-1, 'help', node.help, 'foo', 'bar')
 
         # invalid argument
         assert_raises_rpc_error(-1,
                                 'JSON value is not a string as expected', node.help, 0)
 
         # help of unknown command
         assert_equal(node.help('foo'), 'help: unknown command: foo')
 
         # command titles
         titles = [line[3:-3]
                   for line in node.help().splitlines() if line.startswith('==')]
-        components = ['Blockchain', 'Control', 'Generating',
+        components = ['Avalanche', 'Blockchain', 'Control', 'Generating',
                       'Mining', 'Network', 'Rawtransactions', 'Util']
 
         if self.is_wallet_compiled():
             components.append('Wallet')
 
         if self.is_zmq_compiled():
             components.append('Zmq')
 
         assert_equal(titles, components)
 
 
 if __name__ == '__main__':
     HelpRpcTest().main()
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index 6db012b93..dfc2234c9 100755
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -1,1432 +1,1476 @@
 #!/usr/bin/env python3
 # Copyright (c) 2010 ArtForz -- public domain half-a-node
 # Copyright (c) 2012 Jeff Garzik
 # Copyright (c) 2010-2019 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Bitcoin test framework primitive and message structures
 
 CBlock, CTransaction, CBlockHeader, CTxIn, CTxOut, etc....:
     data structures that should map to corresponding structures in
     bitcoin/primitives
 
 msg_block, msg_tx, msg_headers, etc.:
     data structures that represent network messages
 
 ser_*, deser_*: functions that handle serialization/deserialization.
 
 Classes use __slots__ to ensure extraneous attributes aren't accidentally added
 by tests, compromising their intended effect.
 """
 from codecs import encode
 import copy
 import hashlib
 from io import BytesIO
 import random
 import socket
 import struct
 import time
 
 from test_framework.siphash import siphash256
 from test_framework.util import hex_str_to_bytes
 
 MIN_VERSION_SUPPORTED = 60001
 # past bip-31 for ping/pong
 MY_VERSION = 70014
 MY_SUBVERSION = b"/python-mininode-tester:0.0.3/"
 # from version 70001 onwards, fRelay should be appended to version
 # messages (BIP37)
 MY_RELAY = 1
 
 MAX_INV_SZ = 50000
 MAX_LOCATOR_SZ = 101
 MAX_BLOCK_BASE_SIZE = 1000000
 
 # 1 BCH in satoshis
 COIN = 100000000
 
 NODE_NETWORK = (1 << 0)
 # NODE_GETUTXO = (1 << 1)
 NODE_BLOOM = (1 << 2)
 # NODE_WITNESS = (1 << 3)
 NODE_XTHIN = (1 << 4)
 NODE_BITCOIN_CASH = (1 << 5)
 NODE_NETWORK_LIMITED = (1 << 10)
 NODE_AVALANCHE = (1 << 24)
 
 MSG_TX = 1
 MSG_BLOCK = 2
 MSG_CMPCTBLOCK = 4
 MSG_TYPE_MASK = 0xffffffff >> 2
 
 # Serialization/deserialization tools
 
 
 def sha256(s):
     return hashlib.new('sha256', s).digest()
 
 
 def ripemd160(s):
     return hashlib.new('ripemd160', s).digest()
 
 
 def hash256(s):
     return sha256(sha256(s))
 
 
 def ser_compact_size(l):
     r = b""
     if l < 253:
         r = struct.pack("B", l)
     elif l < 0x10000:
         r = struct.pack("<BH", 253, l)
     elif l < 0x100000000:
         r = struct.pack("<BI", 254, l)
     else:
         r = struct.pack("<BQ", 255, l)
     return r
 
 
 def deser_compact_size(f):
     nit = struct.unpack("<B", f.read(1))[0]
     if nit == 253:
         nit = struct.unpack("<H", f.read(2))[0]
     elif nit == 254:
         nit = struct.unpack("<I", f.read(4))[0]
     elif nit == 255:
         nit = struct.unpack("<Q", f.read(8))[0]
     return nit
 
 
 def deser_string(f):
     nit = deser_compact_size(f)
     return f.read(nit)
 
 
 def ser_string(s):
     return ser_compact_size(len(s)) + s
 
 
 def deser_uint256(f):
     r = 0
     for i in range(8):
         t = struct.unpack("<I", f.read(4))[0]
         r += t << (i * 32)
     return r
 
 
 def ser_uint256(u):
     rs = b""
     for i in range(8):
         rs += struct.pack("<I", u & 0xFFFFFFFF)
         u >>= 32
     return rs
 
 
 def uint256_from_str(s):
     r = 0
     t = struct.unpack("<IIIIIIII", s[:32])
     for i in range(8):
         r += t[i] << (i * 32)
     return r
 
 
 def uint256_from_compact(c):
     nbytes = (c >> 24) & 0xFF
     v = (c & 0xFFFFFF) << (8 * (nbytes - 3))
     return v
 
 
 def deser_vector(f, c):
     nit = deser_compact_size(f)
     r = []
     for i in range(nit):
         t = c()
         t.deserialize(f)
         r.append(t)
     return r
 
 
 # ser_function_name: Allow for an alternate serialization function on the
 # entries in the vector.
 def ser_vector(l, ser_function_name=None):
     r = ser_compact_size(len(l))
     for i in l:
         if ser_function_name:
             r += getattr(i, ser_function_name)()
         else:
             r += i.serialize()
     return r
 
 
 def deser_uint256_vector(f):
     nit = deser_compact_size(f)
     r = []
     for i in range(nit):
         t = deser_uint256(f)
         r.append(t)
     return r
 
 
 def ser_uint256_vector(l):
     r = ser_compact_size(len(l))
     for i in l:
         r += ser_uint256(i)
     return r
 
 
 def deser_string_vector(f):
     nit = deser_compact_size(f)
     r = []
     for i in range(nit):
         t = deser_string(f)
         r.append(t)
     return r
 
 
 def ser_string_vector(l):
     r = ser_compact_size(len(l))
     for sv in l:
         r += ser_string(sv)
     return r
 
 
 # Deserialize from a hex string representation (eg from RPC)
 
 
 def FromHex(obj, hex_string):
     obj.deserialize(BytesIO(hex_str_to_bytes(hex_string)))
     return obj
 
 # Convert a binary-serializable object to hex (eg for submission via RPC)
 
 
 def ToHex(obj):
     return obj.serialize().hex()
 
 # Objects that map to bitcoind objects, which can be serialized/deserialized
 
 
 class CAddress:
     __slots__ = ("ip", "nServices", "pchReserved", "port", "time")
 
     def __init__(self):
         self.time = 0
         self.nServices = 1
         self.pchReserved = b"\x00" * 10 + b"\xff" * 2
         self.ip = "0.0.0.0"
         self.port = 0
 
     def deserialize(self, f, with_time=True):
         if with_time:
             self.time = struct.unpack("<i", f.read(4))[0]
         self.nServices = struct.unpack("<Q", f.read(8))[0]
         self.pchReserved = f.read(12)
         self.ip = socket.inet_ntoa(f.read(4))
         self.port = struct.unpack(">H", f.read(2))[0]
 
     def serialize(self, with_time=True):
         r = b""
         if with_time:
             r += struct.pack("<i", self.time)
         r += struct.pack("<Q", self.nServices)
         r += self.pchReserved
         r += socket.inet_aton(self.ip)
         r += struct.pack(">H", self.port)
         return r
 
     def __repr__(self):
         return "CAddress(nServices={} ip={} port={})".format(
             self.nServices, self.ip, self.port)
 
 
 class CInv:
     __slots__ = ("hash", "type")
 
     typemap = {
         0: "Error",
         1: "TX",
         2: "Block",
         4: "CompactBlock"
     }
 
     def __init__(self, t=0, h=0):
         self.type = t
         self.hash = h
 
     def deserialize(self, f):
         self.type = struct.unpack("<i", f.read(4))[0]
         self.hash = deser_uint256(f)
 
     def serialize(self):
         r = b""
         r += struct.pack("<i", self.type)
         r += ser_uint256(self.hash)
         return r
 
     def __repr__(self):
         return "CInv(type={} hash={:064x})".format(
             self.typemap[self.type], self.hash)
 
 
 class CBlockLocator:
     __slots__ = ("nVersion", "vHave")
 
     def __init__(self):
         self.nVersion = MY_VERSION
         self.vHave = []
 
     def deserialize(self, f):
         self.nVersion = struct.unpack("<i", f.read(4))[0]
         self.vHave = deser_uint256_vector(f)
 
     def serialize(self):
         r = b""
         r += struct.pack("<i", self.nVersion)
         r += ser_uint256_vector(self.vHave)
         return r
 
     def __repr__(self):
         return "CBlockLocator(nVersion={} vHave={})".format(
             self.nVersion, repr(self.vHave))
 
 
 class COutPoint:
     __slots__ = ("hash", "n")
 
     def __init__(self, hash=0, n=0):
         self.hash = hash
         self.n = n
 
     def deserialize(self, f):
         self.hash = deser_uint256(f)
         self.n = struct.unpack("<I", f.read(4))[0]
 
     def serialize(self):
         r = b""
         r += ser_uint256(self.hash)
         r += struct.pack("<I", self.n)
         return r
 
     def __repr__(self):
         return "COutPoint(hash={:064x} n={})".format(self.hash, self.n)
 
 
 class CTxIn:
     __slots__ = ("nSequence", "prevout", "scriptSig")
 
     def __init__(self, outpoint=None, scriptSig=b"", nSequence=0):
         if outpoint is None:
             self.prevout = COutPoint()
         else:
             self.prevout = outpoint
         self.scriptSig = scriptSig
         self.nSequence = nSequence
 
     def deserialize(self, f):
         self.prevout = COutPoint()
         self.prevout.deserialize(f)
         self.scriptSig = deser_string(f)
         self.nSequence = struct.unpack("<I", f.read(4))[0]
 
     def serialize(self):
         r = b""
         r += self.prevout.serialize()
         r += ser_string(self.scriptSig)
         r += struct.pack("<I", self.nSequence)
         return r
 
     def __repr__(self):
         return "CTxIn(prevout={} scriptSig={} nSequence={})".format(
             repr(self.prevout), self.scriptSig.hex(), self.nSequence)
 
 
 class CTxOut:
     __slots__ = ("nValue", "scriptPubKey")
 
     def __init__(self, nValue=0, scriptPubKey=b""):
         self.nValue = nValue
         self.scriptPubKey = scriptPubKey
 
     def deserialize(self, f):
         self.nValue = struct.unpack("<q", f.read(8))[0]
         self.scriptPubKey = deser_string(f)
 
     def serialize(self):
         r = b""
         r += struct.pack("<q", self.nValue)
         r += ser_string(self.scriptPubKey)
         return r
 
     def __repr__(self):
         return "CTxOut(nValue={}.{:08d} scriptPubKey={})".format(
             self.nValue // COIN, self.nValue % COIN, self.scriptPubKey.hex())
 
 
 class CTransaction:
     __slots__ = ("hash", "nLockTime", "nVersion", "sha256", "vin", "vout")
 
     def __init__(self, tx=None):
         if tx is None:
             self.nVersion = 1
             self.vin = []
             self.vout = []
             self.nLockTime = 0
             self.sha256 = None
             self.hash = None
         else:
             self.nVersion = tx.nVersion
             self.vin = copy.deepcopy(tx.vin)
             self.vout = copy.deepcopy(tx.vout)
             self.nLockTime = tx.nLockTime
             self.sha256 = tx.sha256
             self.hash = tx.hash
 
     def deserialize(self, f):
         self.nVersion = struct.unpack("<i", f.read(4))[0]
         self.vin = deser_vector(f, CTxIn)
         self.vout = deser_vector(f, CTxOut)
         self.nLockTime = struct.unpack("<I", f.read(4))[0]
         self.sha256 = None
         self.hash = None
 
     def billable_size(self):
         """
         Returns the size used for billing the against the transaction
         """
         return len(self.serialize())
 
     def serialize(self):
         r = b""
         r += struct.pack("<i", self.nVersion)
         r += ser_vector(self.vin)
         r += ser_vector(self.vout)
         r += struct.pack("<I", self.nLockTime)
         return r
 
     # Recalculate the txid
     def rehash(self):
         self.sha256 = None
         self.calc_sha256()
         return self.hash
 
     # self.sha256 and self.hash -- those are expected to be the txid.
     def calc_sha256(self):
         if self.sha256 is None:
             self.sha256 = uint256_from_str(hash256(self.serialize()))
         self.hash = encode(
             hash256(self.serialize())[::-1], 'hex_codec').decode('ascii')
 
     def get_id(self):
         # For now, just forward the hash.
         self.calc_sha256()
         return self.hash
 
     def is_valid(self):
         self.calc_sha256()
         for tout in self.vout:
             if tout.nValue < 0 or tout.nValue > 21000000 * COIN:
                 return False
         return True
 
     def __repr__(self):
         return "CTransaction(nVersion={} vin={} vout={} nLockTime={})".format(
             self.nVersion, repr(self.vin), repr(self.vout), self.nLockTime)
 
 
 class CBlockHeader:
     __slots__ = ("hash", "hashMerkleRoot", "hashPrevBlock", "nBits", "nNonce",
                  "nTime", "nVersion", "sha256")
 
     def __init__(self, header=None):
         if header is None:
             self.set_null()
         else:
             self.nVersion = header.nVersion
             self.hashPrevBlock = header.hashPrevBlock
             self.hashMerkleRoot = header.hashMerkleRoot
             self.nTime = header.nTime
             self.nBits = header.nBits
             self.nNonce = header.nNonce
             self.sha256 = header.sha256
             self.hash = header.hash
             self.calc_sha256()
 
     def set_null(self):
         self.nVersion = 1
         self.hashPrevBlock = 0
         self.hashMerkleRoot = 0
         self.nTime = 0
         self.nBits = 0
         self.nNonce = 0
         self.sha256 = None
         self.hash = None
 
     def deserialize(self, f):
         self.nVersion = struct.unpack("<i", f.read(4))[0]
         self.hashPrevBlock = deser_uint256(f)
         self.hashMerkleRoot = deser_uint256(f)
         self.nTime = struct.unpack("<I", f.read(4))[0]
         self.nBits = struct.unpack("<I", f.read(4))[0]
         self.nNonce = struct.unpack("<I", f.read(4))[0]
         self.sha256 = None
         self.hash = None
 
     def serialize(self):
         r = b""
         r += struct.pack("<i", self.nVersion)
         r += ser_uint256(self.hashPrevBlock)
         r += ser_uint256(self.hashMerkleRoot)
         r += struct.pack("<I", self.nTime)
         r += struct.pack("<I", self.nBits)
         r += struct.pack("<I", self.nNonce)
         return r
 
     def calc_sha256(self):
         if self.sha256 is None:
             r = b""
             r += struct.pack("<i", self.nVersion)
             r += ser_uint256(self.hashPrevBlock)
             r += ser_uint256(self.hashMerkleRoot)
             r += struct.pack("<I", self.nTime)
             r += struct.pack("<I", self.nBits)
             r += struct.pack("<I", self.nNonce)
             self.sha256 = uint256_from_str(hash256(r))
             self.hash = encode(hash256(r)[::-1], 'hex_codec').decode('ascii')
 
     def rehash(self):
         self.sha256 = None
         self.calc_sha256()
         return self.sha256
 
     def __repr__(self):
         return "CBlockHeader(nVersion={} hashPrevBlock={:064x} hashMerkleRoot={:064x} nTime={} nBits={:08x} nNonce={:08x})".format(
             self.nVersion, self.hashPrevBlock, self.hashMerkleRoot,
             time.ctime(self.nTime), self.nBits, self.nNonce)
 
 
 class CBlock(CBlockHeader):
     __slots__ = ("vtx",)
 
     def __init__(self, header=None):
         super(CBlock, self).__init__(header)
         self.vtx = []
 
     def deserialize(self, f):
         super(CBlock, self).deserialize(f)
         self.vtx = deser_vector(f, CTransaction)
 
     def serialize(self):
         r = b""
         r += super(CBlock, self).serialize()
         r += ser_vector(self.vtx)
         return r
 
     # Calculate the merkle root given a vector of transaction hashes
     def get_merkle_root(self, hashes):
         while len(hashes) > 1:
             newhashes = []
             for i in range(0, len(hashes), 2):
                 i2 = min(i + 1, len(hashes) - 1)
                 newhashes.append(hash256(hashes[i] + hashes[i2]))
             hashes = newhashes
         return uint256_from_str(hashes[0])
 
     def calc_merkle_root(self):
         hashes = []
         for tx in self.vtx:
             tx.calc_sha256()
             hashes.append(ser_uint256(tx.sha256))
         return self.get_merkle_root(hashes)
 
     def is_valid(self):
         self.calc_sha256()
         target = uint256_from_compact(self.nBits)
         if self.sha256 > target:
             return False
         for tx in self.vtx:
             if not tx.is_valid():
                 return False
         if self.calc_merkle_root() != self.hashMerkleRoot:
             return False
         return True
 
     def solve(self):
         self.rehash()
         target = uint256_from_compact(self.nBits)
         while self.sha256 > target:
             self.nNonce += 1
             self.rehash()
 
     def __repr__(self):
         return "CBlock(nVersion={} hashPrevBlock={:064x} hashMerkleRoot={:064x} nTime={} nBits={:08x} nNonce={:08x} vtx={})".format(
             self.nVersion, self.hashPrevBlock, self.hashMerkleRoot,
             time.ctime(self.nTime), self.nBits, self.nNonce, repr(self.vtx))
 
 
 class PrefilledTransaction:
     __slots__ = ("index", "tx")
 
     def __init__(self, index=0, tx=None):
         self.index = index
         self.tx = tx
 
     def deserialize(self, f):
         self.index = deser_compact_size(f)
         self.tx = CTransaction()
         self.tx.deserialize(f)
 
     def serialize(self):
         r = b""
         r += ser_compact_size(self.index)
         r += self.tx.serialize()
         return r
 
     def __repr__(self):
         return "PrefilledTransaction(index={}, tx={})".format(
             self.index, repr(self.tx))
 
 
 # This is what we send on the wire, in a cmpctblock message.
 class P2PHeaderAndShortIDs:
     __slots__ = ("header", "nonce", "prefilled_txn", "prefilled_txn_length",
                  "shortids", "shortids_length")
 
     def __init__(self):
         self.header = CBlockHeader()
         self.nonce = 0
         self.shortids_length = 0
         self.shortids = []
         self.prefilled_txn_length = 0
         self.prefilled_txn = []
 
     def deserialize(self, f):
         self.header.deserialize(f)
         self.nonce = struct.unpack("<Q", f.read(8))[0]
         self.shortids_length = deser_compact_size(f)
         for i in range(self.shortids_length):
             # shortids are defined to be 6 bytes in the spec, so append
             # two zero bytes and read it in as an 8-byte number
             self.shortids.append(
                 struct.unpack("<Q", f.read(6) + b'\x00\x00')[0])
         self.prefilled_txn = deser_vector(f, PrefilledTransaction)
         self.prefilled_txn_length = len(self.prefilled_txn)
 
     def serialize(self):
         r = b""
         r += self.header.serialize()
         r += struct.pack("<Q", self.nonce)
         r += ser_compact_size(self.shortids_length)
         for x in self.shortids:
             # We only want the first 6 bytes
             r += struct.pack("<Q", x)[0:6]
         r += ser_vector(self.prefilled_txn)
         return r
 
     def __repr__(self):
         return "P2PHeaderAndShortIDs(header={}, nonce={}, shortids_length={}, shortids={}, prefilled_txn_length={}, prefilledtxn={}".format(
             repr(self.header), self.nonce, self.shortids_length,
             repr(self.shortids), self.prefilled_txn_length,
             repr(self.prefilled_txn))
 
 # Calculate the BIP 152-compact blocks shortid for a given transaction hash
 
 
 def calculate_shortid(k0, k1, tx_hash):
     expected_shortid = siphash256(k0, k1, tx_hash)
     expected_shortid &= 0x0000ffffffffffff
     return expected_shortid
 
 
 # This version gets rid of the array lengths, and reinterprets the differential
 # encoding into indices that can be used for lookup.
 class HeaderAndShortIDs:
     __slots__ = ("header", "nonce", "prefilled_txn", "shortids")
 
     def __init__(self, p2pheaders_and_shortids=None):
         self.header = CBlockHeader()
         self.nonce = 0
         self.shortids = []
         self.prefilled_txn = []
 
         if p2pheaders_and_shortids is not None:
             self.header = p2pheaders_and_shortids.header
             self.nonce = p2pheaders_and_shortids.nonce
             self.shortids = p2pheaders_and_shortids.shortids
             last_index = -1
             for x in p2pheaders_and_shortids.prefilled_txn:
                 self.prefilled_txn.append(
                     PrefilledTransaction(x.index + last_index + 1, x.tx))
                 last_index = self.prefilled_txn[-1].index
 
     def to_p2p(self):
         ret = P2PHeaderAndShortIDs()
         ret.header = self.header
         ret.nonce = self.nonce
         ret.shortids_length = len(self.shortids)
         ret.shortids = self.shortids
         ret.prefilled_txn_length = len(self.prefilled_txn)
         ret.prefilled_txn = []
         last_index = -1
         for x in self.prefilled_txn:
             ret.prefilled_txn.append(
                 PrefilledTransaction(x.index - last_index - 1, x.tx))
             last_index = x.index
         return ret
 
     def get_siphash_keys(self):
         header_nonce = self.header.serialize()
         header_nonce += struct.pack("<Q", self.nonce)
         hash_header_nonce_as_str = sha256(header_nonce)
         key0 = struct.unpack("<Q", hash_header_nonce_as_str[0:8])[0]
         key1 = struct.unpack("<Q", hash_header_nonce_as_str[8:16])[0]
         return [key0, key1]
 
     # Version 2 compact blocks use wtxid in shortids (rather than txid)
     def initialize_from_block(self, block, nonce=0, prefill_list=[0]):
         self.header = CBlockHeader(block)
         self.nonce = nonce
         self.prefilled_txn = [PrefilledTransaction(i, block.vtx[i])
                               for i in prefill_list]
         self.shortids = []
         [k0, k1] = self.get_siphash_keys()
         for i in range(len(block.vtx)):
             if i not in prefill_list:
                 tx_hash = block.vtx[i].sha256
                 self.shortids.append(calculate_shortid(k0, k1, tx_hash))
 
     def __repr__(self):
         return "HeaderAndShortIDs(header={}, nonce={}, shortids={}, prefilledtxn={}".format(
             repr(self.header), self.nonce, repr(self.shortids),
             repr(self.prefilled_txn))
 
 
 class BlockTransactionsRequest:
     __slots__ = ("blockhash", "indexes")
 
     def __init__(self, blockhash=0, indexes=None):
         self.blockhash = blockhash
         self.indexes = indexes if indexes is not None else []
 
     def deserialize(self, f):
         self.blockhash = deser_uint256(f)
         indexes_length = deser_compact_size(f)
         for i in range(indexes_length):
             self.indexes.append(deser_compact_size(f))
 
     def serialize(self):
         r = b""
         r += ser_uint256(self.blockhash)
         r += ser_compact_size(len(self.indexes))
         for x in self.indexes:
             r += ser_compact_size(x)
         return r
 
     # helper to set the differentially encoded indexes from absolute ones
     def from_absolute(self, absolute_indexes):
         self.indexes = []
         last_index = -1
         for x in absolute_indexes:
             self.indexes.append(x - last_index - 1)
             last_index = x
 
     def to_absolute(self):
         absolute_indexes = []
         last_index = -1
         for x in self.indexes:
             absolute_indexes.append(x + last_index + 1)
             last_index = absolute_indexes[-1]
         return absolute_indexes
 
     def __repr__(self):
         return "BlockTransactionsRequest(hash={:064x} indexes={})".format(
             self.blockhash, repr(self.indexes))
 
 
 class BlockTransactions:
     __slots__ = ("blockhash", "transactions")
 
     def __init__(self, blockhash=0, transactions=None):
         self.blockhash = blockhash
         self.transactions = transactions if transactions is not None else []
 
     def deserialize(self, f):
         self.blockhash = deser_uint256(f)
         self.transactions = deser_vector(f, CTransaction)
 
     def serialize(self):
         r = b""
         r += ser_uint256(self.blockhash)
         r += ser_vector(self.transactions)
         return r
 
     def __repr__(self):
         return "BlockTransactions(hash={:064x} transactions={})".format(
             self.blockhash, repr(self.transactions))
 
 
 class AvalanchePoll():
     __slots__ = ("round", "invs")
 
     def __init__(self, round=0, invs=None):
         self.round = round
         self.invs = invs if invs is not None else []
 
     def deserialize(self, f):
         self.round = struct.unpack("<q", f.read(8))[0]
         self.invs = deser_vector(f, CInv)
 
     def serialize(self):
         r = b""
         r += struct.pack("<q", self.round)
         r += ser_vector(self.invs)
         return r
 
     def __repr__(self):
         return "AvalanchePoll(round={}, invs={})".format(
             self.round, repr(self.invs))
 
 
 class AvalancheVote():
     __slots__ = ("error", "hash")
 
     def __init__(self, e=0, h=0):
         self.error = e
         self.hash = h
 
     def deserialize(self, f):
         self.error = struct.unpack("<i", f.read(4))[0]
         self.hash = deser_uint256(f)
 
     def serialize(self):
         r = b""
         r += struct.pack("<i", self.error)
         r += ser_uint256(self.hash)
         return r
 
     def __repr__(self):
         return "AvalancheVote(error={}, hash={:064x})".format(
             self.error, self.hash)
 
 
 class AvalancheResponse():
     __slots__ = ("round", "cooldown", "votes")
 
     def __init__(self, round=0, cooldown=0, votes=None):
         self.round = round
         self.cooldown = cooldown
         self.votes = votes if votes is not None else []
 
     def deserialize(self, f):
         self.round = struct.unpack("<q", f.read(8))[0]
         self.cooldown = struct.unpack("<i", f.read(4))[0]
         self.votes = deser_vector(f, AvalancheVote)
 
     def serialize(self):
         r = b""
         r += struct.pack("<q", self.round)
         r += struct.pack("<i", self.cooldown)
         r += ser_vector(self.votes)
         return r
 
+    def get_hash(self):
+        return hash256(self.serialize())
+
     def __repr__(self):
         return "AvalancheResponse(round={}, cooldown={}, votes={})".format(
             self.round, self.cooldown, repr(self.votes))
 
 
+class TCPAvalancheResponse():
+    __slots__ = ("response", "sig")
+
+    def __init__(self, response=AvalancheResponse()):
+        self.response = response
+        self.sig = b"\0" * 64
+
+    def deserialize(self, f):
+        self.response.deserialize(f)
+        self.sig = f.read(64)
+
+    def serialize(self):
+        r = b""
+        r += self.response.serialize()
+        r += self.sig
+        return r
+
+    def __repr__(self):
+        return "TCPAvalancheResponse(response={}, sig={})".format(
+            repr(self.response), self.sig)
+
+
 class CPartialMerkleTree:
     __slots__ = ("fBad", "nTransactions", "vBits", "vHash")
 
     def __init__(self):
         self.nTransactions = 0
         self.vHash = []
         self.vBits = []
         self.fBad = False
 
     def deserialize(self, f):
         self.nTransactions = struct.unpack("<i", f.read(4))[0]
         self.vHash = deser_uint256_vector(f)
         vBytes = deser_string(f)
         self.vBits = []
         for i in range(len(vBytes) * 8):
             self.vBits.append(vBytes[i // 8] & (1 << (i % 8)) != 0)
 
     def serialize(self):
         r = b""
         r += struct.pack("<i", self.nTransactions)
         r += ser_uint256_vector(self.vHash)
         vBytesArray = bytearray([0x00] * ((len(self.vBits) + 7) // 8))
         for i in range(len(self.vBits)):
             vBytesArray[i // 8] |= self.vBits[i] << (i % 8)
         r += ser_string(bytes(vBytesArray))
         return r
 
     def __repr__(self):
         return "CPartialMerkleTree(nTransactions={}, vHash={}, vBits={})".format(
             self.nTransactions, repr(self.vHash), repr(self.vBits))
 
 
 class CMerkleBlock:
     __slots__ = ("header", "txn")
 
     def __init__(self):
         self.header = CBlockHeader()
         self.txn = CPartialMerkleTree()
 
     def deserialize(self, f):
         self.header.deserialize(f)
         self.txn.deserialize(f)
 
     def serialize(self):
         r = b""
         r += self.header.serialize()
         r += self.txn.serialize()
         return r
 
     def __repr__(self):
         return "CMerkleBlock(header={}, txn={})".format(
             repr(self.header), repr(self.txn))
 
 
 # Objects that correspond to messages on the wire
 
 
 class msg_version:
     __slots__ = ("addrFrom", "addrTo", "nNonce", "nRelay", "nServices",
                  "nStartingHeight", "nTime", "nVersion", "strSubVer")
     command = b"version"
 
     def __init__(self):
         self.nVersion = MY_VERSION
         self.nServices = 1
         self.nTime = int(time.time())
         self.addrTo = CAddress()
         self.addrFrom = CAddress()
         self.nNonce = random.getrandbits(64)
         self.strSubVer = MY_SUBVERSION
         self.nStartingHeight = -1
         self.nRelay = MY_RELAY
 
     def deserialize(self, f):
         self.nVersion = struct.unpack("<i", f.read(4))[0]
         self.nServices = struct.unpack("<Q", f.read(8))[0]
         self.nTime = struct.unpack("<q", f.read(8))[0]
         self.addrTo = CAddress()
         self.addrTo.deserialize(f, False)
 
         self.addrFrom = CAddress()
         self.addrFrom.deserialize(f, False)
         self.nNonce = struct.unpack("<Q", f.read(8))[0]
         self.strSubVer = deser_string(f)
 
         self.nStartingHeight = struct.unpack("<i", f.read(4))[0]
 
         if self.nVersion >= 70001:
             # Relay field is optional for version 70001 onwards
             try:
                 self.nRelay = struct.unpack("<b", f.read(1))[0]
             except Exception:
                 self.nRelay = 0
         else:
             self.nRelay = 0
 
     def serialize(self):
         r = b""
         r += struct.pack("<i", self.nVersion)
         r += struct.pack("<Q", self.nServices)
         r += struct.pack("<q", self.nTime)
         r += self.addrTo.serialize(False)
         r += self.addrFrom.serialize(False)
         r += struct.pack("<Q", self.nNonce)
         r += ser_string(self.strSubVer)
         r += struct.pack("<i", self.nStartingHeight)
         r += struct.pack("<b", self.nRelay)
         return r
 
     def __repr__(self):
         return 'msg_version(nVersion={} nServices={} nTime={} addrTo={} addrFrom={} nNonce=0x{:016X} strSubVer={} nStartingHeight={} nRelay={})'.format(
             self.nVersion, self.nServices, time.ctime(self.nTime),
             repr(self.addrTo), repr(self.addrFrom), self.nNonce,
             self.strSubVer, self.nStartingHeight, self.nRelay)
 
 
 class msg_verack:
     __slots__ = ()
     command = b"verack"
 
     def __init__(self):
         pass
 
     def deserialize(self, f):
         pass
 
     def serialize(self):
         return b""
 
     def __repr__(self):
         return "msg_verack()"
 
 
 class msg_addr:
     __slots__ = ("addrs",)
     command = b"addr"
 
     def __init__(self):
         self.addrs = []
 
     def deserialize(self, f):
         self.addrs = deser_vector(f, CAddress)
 
     def serialize(self):
         return ser_vector(self.addrs)
 
     def __repr__(self):
         return "msg_addr(addrs={})".format(repr(self.addrs))
 
 
 class msg_inv:
     __slots__ = ("inv",)
     command = b"inv"
 
     def __init__(self, inv=None):
         if inv is None:
             self.inv = []
         else:
             self.inv = inv
 
     def deserialize(self, f):
         self.inv = deser_vector(f, CInv)
 
     def serialize(self):
         return ser_vector(self.inv)
 
     def __repr__(self):
         return "msg_inv(inv={})".format(repr(self.inv))
 
 
 class msg_getdata:
     __slots__ = ("inv",)
     command = b"getdata"
 
     def __init__(self, inv=None):
         self.inv = inv if inv is not None else []
 
     def deserialize(self, f):
         self.inv = deser_vector(f, CInv)
 
     def serialize(self):
         return ser_vector(self.inv)
 
     def __repr__(self):
         return "msg_getdata(inv={})".format(repr(self.inv))
 
 
 class msg_getblocks:
     __slots__ = ("locator", "hashstop")
     command = b"getblocks"
 
     def __init__(self):
         self.locator = CBlockLocator()
         self.hashstop = 0
 
     def deserialize(self, f):
         self.locator = CBlockLocator()
         self.locator.deserialize(f)
         self.hashstop = deser_uint256(f)
 
     def serialize(self):
         r = b""
         r += self.locator.serialize()
         r += ser_uint256(self.hashstop)
         return r
 
     def __repr__(self):
         return "msg_getblocks(locator={} hashstop={:064x})".format(
             repr(self.locator), self.hashstop)
 
 
 class msg_tx:
     __slots__ = ("tx",)
     command = b"tx"
 
     def __init__(self, tx=CTransaction()):
         self.tx = tx
 
     def deserialize(self, f):
         self.tx.deserialize(f)
 
     def serialize(self):
         return self.tx.serialize()
 
     def __repr__(self):
         return "msg_tx(tx={})".format(repr(self.tx))
 
 
 class msg_block:
     __slots__ = ("block",)
     command = b"block"
 
     def __init__(self, block=None):
         if block is None:
             self.block = CBlock()
         else:
             self.block = block
 
     def deserialize(self, f):
         self.block.deserialize(f)
 
     def serialize(self):
         return self.block.serialize()
 
     def __repr__(self):
         return "msg_block(block={})".format(repr(self.block))
 
 
 # for cases where a user needs tighter control over what is sent over the wire
 # note that the user must supply the name of the command, and the data
 
 
 class msg_generic:
     __slots__ = ("command", "data")
 
     def __init__(self, command, data=None):
         self.command = command
         self.data = data
 
     def serialize(self):
         return self.data
 
     def __repr__(self):
         return "msg_generic()"
 
 
 class msg_getaddr:
     __slots__ = ()
     command = b"getaddr"
 
     def __init__(self):
         pass
 
     def deserialize(self, f):
         pass
 
     def serialize(self):
         return b""
 
     def __repr__(self):
         return "msg_getaddr()"
 
 
 class msg_ping:
     __slots__ = ("nonce",)
     command = b"ping"
 
     def __init__(self, nonce=0):
         self.nonce = nonce
 
     def deserialize(self, f):
         self.nonce = struct.unpack("<Q", f.read(8))[0]
 
     def serialize(self):
         r = b""
         r += struct.pack("<Q", self.nonce)
         return r
 
     def __repr__(self):
         return "msg_ping(nonce={:08x})".format(self.nonce)
 
 
 class msg_pong:
     __slots__ = ("nonce",)
     command = b"pong"
 
     def __init__(self, nonce=0):
         self.nonce = nonce
 
     def deserialize(self, f):
         self.nonce = struct.unpack("<Q", f.read(8))[0]
 
     def serialize(self):
         r = b""
         r += struct.pack("<Q", self.nonce)
         return r
 
     def __repr__(self):
         return "msg_pong(nonce={:08x})".format(self.nonce)
 
 
 class msg_mempool:
     __slots__ = ()
     command = b"mempool"
 
     def __init__(self):
         pass
 
     def deserialize(self, f):
         pass
 
     def serialize(self):
         return b""
 
     def __repr__(self):
         return "msg_mempool()"
 
 
 class msg_notfound:
     __slots__ = ("vec", )
     command = b"notfound"
 
     def __init__(self, vec=None):
         self.vec = vec or []
 
     def deserialize(self, f):
         self.vec = deser_vector(f, CInv)
 
     def serialize(self):
         return ser_vector(self.vec)
 
     def __repr__(self):
         return "msg_notfound(vec={})".format(repr(self.vec))
 
 
 class msg_sendheaders:
     __slots__ = ()
     command = b"sendheaders"
 
     def __init__(self):
         pass
 
     def deserialize(self, f):
         pass
 
     def serialize(self):
         return b""
 
     def __repr__(self):
         return "msg_sendheaders()"
 
 
 # getheaders message has
 # number of entries
 # vector of hashes
 # hash_stop (hash of last desired block header, 0 to get as many as possible)
 class msg_getheaders:
     __slots__ = ("hashstop", "locator",)
     command = b"getheaders"
 
     def __init__(self):
         self.locator = CBlockLocator()
         self.hashstop = 0
 
     def deserialize(self, f):
         self.locator = CBlockLocator()
         self.locator.deserialize(f)
         self.hashstop = deser_uint256(f)
 
     def serialize(self):
         r = b""
         r += self.locator.serialize()
         r += ser_uint256(self.hashstop)
         return r
 
     def __repr__(self):
         return "msg_getheaders(locator={}, stop={:064x})".format(
             repr(self.locator), self.hashstop)
 
 
 # headers message has
 # <count> <vector of block headers>
 class msg_headers:
     __slots__ = ("headers",)
     command = b"headers"
 
     def __init__(self, headers=None):
         self.headers = headers if headers is not None else []
 
     def deserialize(self, f):
         # comment in bitcoind indicates these should be deserialized as blocks
         blocks = deser_vector(f, CBlock)
         for x in blocks:
             self.headers.append(CBlockHeader(x))
 
     def serialize(self):
         blocks = [CBlock(x) for x in self.headers]
         return ser_vector(blocks)
 
     def __repr__(self):
         return "msg_headers(headers={})".format(repr(self.headers))
 
 
 class msg_reject:
     __slots__ = ("code", "data", "message", "reason")
     command = b"reject"
     REJECT_MALFORMED = 1
 
     def __init__(self):
         self.message = b""
         self.code = 0
         self.reason = b""
         self.data = 0
 
     def deserialize(self, f):
         self.message = deser_string(f)
         self.code = struct.unpack("<B", f.read(1))[0]
         self.reason = deser_string(f)
         if (self.code != self.REJECT_MALFORMED
                 and (self.message == b"block" or self.message == b"tx")):
             self.data = deser_uint256(f)
 
     def serialize(self):
         r = ser_string(self.message)
         r += struct.pack("<B", self.code)
         r += ser_string(self.reason)
         if (self.code != self.REJECT_MALFORMED
                 and (self.message == b"block" or self.message == b"tx")):
             r += ser_uint256(self.data)
         return r
 
     def __repr__(self):
         return "msg_reject: {} {} {} [{:064x}]".format(
             self.message, self.code, self.reason, self.data)
 
 
 class msg_feefilter:
     __slots__ = ("feerate",)
     command = b"feefilter"
 
     def __init__(self, feerate=0):
         self.feerate = feerate
 
     def deserialize(self, f):
         self.feerate = struct.unpack("<Q", f.read(8))[0]
 
     def serialize(self):
         r = b""
         r += struct.pack("<Q", self.feerate)
         return r
 
     def __repr__(self):
         return "msg_feefilter(feerate={:08x})".format(self.feerate)
 
 
 class msg_sendcmpct:
     __slots__ = ("announce", "version")
     command = b"sendcmpct"
 
     def __init__(self):
         self.announce = False
         self.version = 1
 
     def deserialize(self, f):
         self.announce = struct.unpack("<?", f.read(1))[0]
         self.version = struct.unpack("<Q", f.read(8))[0]
 
     def serialize(self):
         r = b""
         r += struct.pack("<?", self.announce)
         r += struct.pack("<Q", self.version)
         return r
 
     def __repr__(self):
         return "msg_sendcmpct(announce={}, version={})".format(
             self.announce, self.version)
 
 
 class msg_cmpctblock:
     __slots__ = ("header_and_shortids",)
     command = b"cmpctblock"
 
     def __init__(self, header_and_shortids=None):
         self.header_and_shortids = header_and_shortids
 
     def deserialize(self, f):
         self.header_and_shortids = P2PHeaderAndShortIDs()
         self.header_and_shortids.deserialize(f)
 
     def serialize(self):
         r = b""
         r += self.header_and_shortids.serialize()
         return r
 
     def __repr__(self):
         return "msg_cmpctblock(HeaderAndShortIDs={})".format(
             repr(self.header_and_shortids))
 
 
 class msg_getblocktxn:
     __slots__ = ("block_txn_request",)
     command = b"getblocktxn"
 
     def __init__(self):
         self.block_txn_request = None
 
     def deserialize(self, f):
         self.block_txn_request = BlockTransactionsRequest()
         self.block_txn_request.deserialize(f)
 
     def serialize(self):
         r = b""
         r += self.block_txn_request.serialize()
         return r
 
     def __repr__(self):
         return "msg_getblocktxn(block_txn_request={})".format(
             repr(self.block_txn_request))
 
 
 class msg_blocktxn:
     __slots__ = ("block_transactions",)
     command = b"blocktxn"
 
     def __init__(self):
         self.block_transactions = BlockTransactions()
 
     def deserialize(self, f):
         self.block_transactions.deserialize(f)
 
     def serialize(self):
         r = b""
         r += self.block_transactions.serialize()
         return r
 
     def __repr__(self):
         return "msg_blocktxn(block_transactions={})".format(
             repr(self.block_transactions))
 
 
 class msg_avapoll():
     __slots__ = ("poll",)
     command = b"avapoll"
 
     def __init__(self):
         self.poll = AvalanchePoll()
 
     def deserialize(self, f):
         self.poll.deserialize(f)
 
     def serialize(self):
         r = b""
         r += self.poll.serialize()
         return r
 
     def __repr__(self):
         return "msg_avapoll(poll={})".format(repr(self.poll))
 
 
 class msg_avaresponse():
     __slots__ = ("response",)
     command = b"avaresponse"
 
     def __init__(self):
         self.response = AvalancheResponse()
 
     def deserialize(self, f):
         self.response.deserialize(f)
 
     def serialize(self):
         r = b""
         r += self.response.serialize()
         return r
 
     def __repr__(self):
         return "msg_avaresponse(response={})".format(repr(self.response))
+
+
+class msg_tcpavaresponse():
+    __slots__ = ("response",)
+    command = b"avaresponse"
+
+    def __init__(self):
+        self.response = TCPAvalancheResponse()
+
+    def deserialize(self, f):
+        self.response.deserialize(f)
+
+    def serialize(self):
+        r = b""
+        r += self.response.serialize()
+        return r
+
+    def __repr__(self):
+        return "msg_tcpavaresponse(response={})".format(repr(self.response))
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index 7abf8ec51..e304737e8 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -1,653 +1,653 @@
 #!/usr/bin/env python3
 # Copyright (c) 2010 ArtForz -- public domain half-a-node
 # Copyright (c) 2012 Jeff Garzik
 # Copyright (c) 2010-2019 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Bitcoin P2P network half-a-node.
 
 This python code was modified from ArtForz' public domain half-a-node, as
 found in the mini-node branch of http://github.com/jgarzik/pynode.
 
 P2PConnection: A low-level connection object to a node's P2P interface
 P2PInterface: A high-level interface object for communicating to a node over P2P
 P2PDataStore: A p2p interface class that keeps a store of transactions and blocks
               and can respond correctly to getdata and getheaders messages"""
 import asyncio
 from collections import defaultdict
 from io import BytesIO
 import logging
 import struct
 import sys
 import threading
 
 from test_framework.messages import (
     CBlockHeader,
     MIN_VERSION_SUPPORTED,
     msg_addr,
     msg_avapoll,
-    msg_avaresponse,
+    msg_tcpavaresponse,
     msg_block,
     MSG_BLOCK,
     msg_blocktxn,
     msg_cmpctblock,
     msg_feefilter,
     msg_getaddr,
     msg_getblocks,
     msg_getblocktxn,
     msg_getdata,
     msg_getheaders,
     msg_headers,
     msg_inv,
     msg_mempool,
     msg_notfound,
     msg_ping,
     msg_pong,
     msg_reject,
     msg_sendcmpct,
     msg_sendheaders,
     msg_tx,
     MSG_TX,
     MSG_TYPE_MASK,
     msg_verack,
     msg_version,
     NODE_NETWORK,
     sha256,
 )
 from test_framework.util import wait_until
 
 logger = logging.getLogger("TestFramework.mininode")
 
 MESSAGEMAP = {
     b"addr": msg_addr,
     b"avapoll": msg_avapoll,
-    b"avaresponse": msg_avaresponse,
+    b"avaresponse": msg_tcpavaresponse,
     b"block": msg_block,
     b"blocktxn": msg_blocktxn,
     b"cmpctblock": msg_cmpctblock,
     b"feefilter": msg_feefilter,
     b"getaddr": msg_getaddr,
     b"getblocks": msg_getblocks,
     b"getblocktxn": msg_getblocktxn,
     b"getdata": msg_getdata,
     b"getheaders": msg_getheaders,
     b"headers": msg_headers,
     b"inv": msg_inv,
     b"mempool": msg_mempool,
     b"notfound": msg_notfound,
     b"ping": msg_ping,
     b"pong": msg_pong,
     b"reject": msg_reject,
     b"sendcmpct": msg_sendcmpct,
     b"sendheaders": msg_sendheaders,
     b"tx": msg_tx,
     b"verack": msg_verack,
     b"version": msg_version,
 }
 
 MAGIC_BYTES = {
     "mainnet": b"\xe3\xe1\xf3\xe8",
     "testnet3": b"\xf4\xe5\xf3\xf4",
     "regtest": b"\xda\xb5\xbf\xfa",
 }
 
 
 class P2PConnection(asyncio.Protocol):
     """A low-level connection object to a node's P2P interface.
 
     This class is responsible for:
 
     - opening and closing the TCP connection to the node
     - reading bytes from and writing bytes to the socket
     - deserializing and serializing the P2P message header
     - logging messages as they are sent and received
 
     This class contains no logic for handing the P2P message payloads. It must be
     sub-classed and the on_message() callback overridden."""
 
     def __init__(self):
         # The underlying transport of the connection.
         # Should only call methods on this from the NetworkThread, c.f.
         # call_soon_threadsafe
         self._transport = None
 
     @property
     def is_connected(self):
         return self._transport is not None
 
     def peer_connect(self, dstaddr, dstport, net="regtest"):
         assert not self.is_connected
         self.dstaddr = dstaddr
         self.dstport = dstport
         # The initial message to send after the connection was made:
         self.on_connection_send_msg = None
         self.on_connection_send_msg_is_raw = False
         self.recvbuf = b""
         self.network = net
         logger.debug('Connecting to Bitcoin Node: {}:{}'.format(
             self.dstaddr, self.dstport))
 
         loop = NetworkThread.network_event_loop
         conn_gen_unsafe = loop.create_connection(
             lambda: self, host=self.dstaddr, port=self.dstport)
 
         def conn_gen(): return loop.call_soon_threadsafe(
             loop.create_task, conn_gen_unsafe)
         return conn_gen
 
     def peer_disconnect(self):
         # Connection could have already been closed by other end.
         NetworkThread.network_event_loop.call_soon_threadsafe(
             lambda: self._transport and self._transport.abort())
 
     # Connection and disconnection methods
 
     def connection_made(self, transport):
         """asyncio callback when a connection is opened."""
         assert not self._transport
         logger.debug("Connected & Listening: {}:{}".format(
             self.dstaddr, self.dstport))
         self._transport = transport
         if self.on_connection_send_msg:
             if self.on_connection_send_msg_is_raw:
                 self.send_raw_message(self.on_connection_send_msg)
             else:
                 self.send_message(self.on_connection_send_msg)
             # Never used again
             self.on_connection_send_msg = None
         self.on_open()
 
     def connection_lost(self, exc):
         """asyncio callback when a connection is closed."""
         if exc:
             logger.warning("Connection lost to {}:{} due to {}".format(
                 self.dstaddr, self.dstport, exc))
         else:
             logger.debug("Closed connection to: {}:{}".format(
                 self.dstaddr, self.dstport))
         self._transport = None
         self.recvbuf = b""
         self.on_close()
 
     # Socket read methods
 
     def data_received(self, t):
         """asyncio callback when data is read from the socket."""
         with mininode_lock:
             if len(t) > 0:
                 self.recvbuf += t
 
         while True:
             msg = self._on_data()
             if msg is None:
                 break
             self.on_message(msg)
 
     def _on_data(self):
         """Try to read P2P messages from the recv buffer.
 
         This method reads data from the buffer in a loop. It deserializes,
         parses and verifies the P2P header, then passes the P2P payload to
         the on_message callback for processing."""
         try:
             with mininode_lock:
                 if len(self.recvbuf) < 4:
                     return None
                 if self.recvbuf[:4] != MAGIC_BYTES[self.network]:
                     raise ValueError(
                         "got garbage {}".format(repr(self.recvbuf)))
                 if len(self.recvbuf) < 4 + 12 + 4 + 4:
                     return None
                 command = self.recvbuf[4:4 + 12].split(b"\x00", 1)[0]
                 msglen = struct.unpack(
                     "<i", self.recvbuf[4 + 12:4 + 12 + 4])[0]
                 checksum = self.recvbuf[4 + 12 + 4:4 + 12 + 4 + 4]
                 if len(self.recvbuf) < 4 + 12 + 4 + 4 + msglen:
                     return None
                 msg = self.recvbuf[4 + 12 + 4 + 4:4 + 12 + 4 + 4 + msglen]
                 h = sha256(sha256(msg))
                 if checksum != h[:4]:
                     raise ValueError("got bad checksum " + repr(self.recvbuf))
                 self.recvbuf = self.recvbuf[4 + 12 + 4 + 4 + msglen:]
                 if command not in MESSAGEMAP:
                     raise ValueError("Received unknown command from {}:{}: '{}' {}".format(
                         self.dstaddr, self.dstport, command, repr(msg)))
                 f = BytesIO(msg)
                 m = MESSAGEMAP[command]()
                 m.deserialize(f)
                 self._log_message("receive", m)
                 return m
         except Exception as e:
             logger.exception('Error reading message:', repr(e))
             raise
 
     def on_message(self, message):
         """Callback for processing a P2P payload. Must be overridden by derived class."""
         raise NotImplementedError
 
     # Socket write methods
 
     def send_message(self, message):
         """Send a P2P message over the socket.
 
         This method takes a P2P payload, builds the P2P header and adds
         the message to the send buffer to be sent over the socket."""
         if not self.is_connected:
             raise IOError('Not connected')
         self._log_message("send", message)
         tmsg = self._build_message(message)
         self.send_raw_message(tmsg)
 
     def send_raw_message(self, tmsg):
         """Send any raw message over the socket.
 
         This method adds a raw message to the send buffer to be sent over the
         socket."""
         if not self.is_connected:
             raise IOError('Not connected')
 
         def maybe_write():
             if not self._transport:
                 return
             if self._transport.is_closing():
                 return
             self._transport.write(tmsg)
         NetworkThread.network_event_loop.call_soon_threadsafe(maybe_write)
 
     # Class utility methods
 
     def _build_message(self, message):
         """Build a serialized P2P message"""
         command = message.command
         data = message.serialize()
         tmsg = MAGIC_BYTES[self.network]
         tmsg += command
         tmsg += b"\x00" * (12 - len(command))
         tmsg += struct.pack("<I", len(data))
         th = sha256(data)
         h = sha256(th)
         tmsg += h[:4]
         tmsg += data
         return tmsg
 
     def _log_message(self, direction, msg):
         """Logs a message being sent or received over the connection."""
         if direction == "send":
             log_message = "Send message to "
         elif direction == "receive":
             log_message = "Received message from "
         log_message += "{}:{}: {}".format(
             self.dstaddr, self.dstport, repr(msg)[:500])
         if len(log_message) > 500:
             log_message += "... (msg truncated)"
         logger.debug(log_message)
 
 
 class P2PInterface(P2PConnection):
     """A high-level P2P interface class for communicating with a Bitcoin Cash node.
 
     This class provides high-level callbacks for processing P2P message
     payloads, as well as convenience methods for interacting with the
     node over P2P.
 
     Individual testcases should subclass this and override the on_* methods
     if they want to alter message handling behaviour."""
 
     def __init__(self):
         super().__init__()
 
         # Track number of messages of each type received and the most recent
         # message of each type
         self.message_count = defaultdict(int)
         self.last_message = {}
 
         # A count of the number of ping messages we've sent to the node
         self.ping_counter = 1
 
         # The network services received from the peer
         self.nServices = 0
 
     def peer_connect(self, *args, services=NODE_NETWORK,
                      send_version=True, **kwargs):
         create_conn = super().peer_connect(*args, **kwargs)
 
         if send_version:
             # Send a version msg
             vt = msg_version()
             vt.nServices = services
             vt.addrTo.ip = self.dstaddr
             vt.addrTo.port = self.dstport
             vt.addrFrom.ip = "0.0.0.0"
             vt.addrFrom.port = 0
             # Will be sent soon after connection_made
             self.on_connection_send_msg = vt
 
         return create_conn
 
     # Message receiving methods
 
     def on_message(self, message):
         """Receive message and dispatch message to appropriate callback.
 
         We keep a count of how many of each message type has been received
         and the most recent message of each type."""
         with mininode_lock:
             try:
                 command = message.command.decode('ascii')
                 self.message_count[command] += 1
                 self.last_message[command] = message
                 getattr(self, 'on_' + command)(message)
             except Exception:
                 print("ERROR delivering {} ({})".format(
                     repr(message), sys.exc_info()[0]))
                 raise
 
     # Callback methods. Can be overridden by subclasses in individual test
     # cases to provide custom message handling behaviour.
 
     def on_open(self):
         pass
 
     def on_close(self):
         pass
 
     def on_addr(self, message): pass
 
     def on_avapoll(self, message): pass
 
     def on_avaresponse(self, message): pass
 
     def on_block(self, message): pass
 
     def on_blocktxn(self, message): pass
 
     def on_cmpctblock(self, message): pass
 
     def on_feefilter(self, message): pass
 
     def on_getaddr(self, message): pass
 
     def on_getblocks(self, message): pass
 
     def on_getblocktxn(self, message): pass
 
     def on_getdata(self, message): pass
 
     def on_getheaders(self, message): pass
 
     def on_headers(self, message): pass
 
     def on_mempool(self, message): pass
 
     def on_notfound(self, message): pass
 
     def on_pong(self, message): pass
 
     def on_reject(self, message): pass
 
     def on_sendcmpct(self, message): pass
 
     def on_sendheaders(self, message): pass
 
     def on_tx(self, message): pass
 
     def on_inv(self, message):
         want = msg_getdata()
         for i in message.inv:
             if i.type != 0:
                 want.inv.append(i)
         if len(want.inv):
             self.send_message(want)
 
     def on_ping(self, message):
         self.send_message(msg_pong(message.nonce))
 
     def on_verack(self, message):
         self.verack_received = True
 
     def on_version(self, message):
         assert message.nVersion >= MIN_VERSION_SUPPORTED, "Version {} received. Test framework only supports versions greater than {}".format(
             message.nVersion, MIN_VERSION_SUPPORTED)
         self.send_message(msg_verack())
         self.nServices = message.nServices
 
     # Connection helper methods
 
     def wait_for_disconnect(self, timeout=60):
         def test_function(): return not self.is_connected
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
     # Message receiving helper methods
 
     def wait_for_block(self, blockhash, timeout=60):
         def test_function(): return self.last_message.get(
             "block") and self.last_message["block"].block.rehash() == blockhash
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
     def wait_for_header(self, blockhash, timeout=60):
         def test_function():
             last_headers = self.last_message.get('headers')
             if not last_headers:
                 return False
             return last_headers.headers[0].rehash() == blockhash
 
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
     def wait_for_getdata(self, timeout=60):
         """Waits for a getdata message.
 
         Receiving any getdata message will satisfy the predicate. the last_message["getdata"]
         value must be explicitly cleared before calling this method, or this will return
         immediately with success. TODO: change this method to take a hash value and only
         return true if the correct block/tx has been requested."""
         def test_function(): return self.last_message.get("getdata")
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
     def wait_for_getheaders(self, timeout=60):
         """Waits for a getheaders message.
 
         Receiving any getheaders message will satisfy the predicate. the last_message["getheaders"]
         value must be explicitly cleared before calling this method, or this will return
         immediately with success. TODO: change this method to take a hash value and only
         return true if the correct block header has been requested."""
         def test_function(): return self.last_message.get("getheaders")
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
     def wait_for_inv(self, expected_inv, timeout=60):
         """Waits for an INV message and checks that the first inv object in the message was as expected."""
         if len(expected_inv) > 1:
             raise NotImplementedError(
                 "wait_for_inv() will only verify the first inv object")
 
         def test_function(): return self.last_message.get("inv") and \
             self.last_message["inv"].inv[0].type == expected_inv[0].type and \
             self.last_message["inv"].inv[0].hash == expected_inv[0].hash
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
     def wait_for_verack(self, timeout=60):
         def test_function(): return self.message_count["verack"]
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
     # Message sending helper functions
 
     def send_and_ping(self, message):
         self.send_message(message)
         self.sync_with_ping()
 
     # Sync up with the node
     def sync_with_ping(self, timeout=60):
         self.send_message(msg_ping(nonce=self.ping_counter))
 
         def test_function():
             if not self.last_message.get("pong"):
                 return False
             return self.last_message["pong"].nonce == self.ping_counter
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
         self.ping_counter += 1
 
 
 # One lock for synchronizing all data access between the networking thread (see
 # NetworkThread below) and the thread running the test logic.  For simplicity,
 # P2PConnection acquires this lock whenever delivering a message to a P2PInterface.
 # This lock should be acquired in the thread running the test logic to synchronize
 # access to any data shared with the P2PInterface or P2PConnection.
 mininode_lock = threading.RLock()
 
 
 class NetworkThread(threading.Thread):
     network_event_loop = None
 
     def __init__(self):
         super().__init__(name="NetworkThread")
         # There is only one event loop and no more than one thread must be
         # created
         assert not self.network_event_loop
 
         NetworkThread.network_event_loop = asyncio.new_event_loop()
 
     def run(self):
         """Start the network thread."""
         self.network_event_loop.run_forever()
 
     def close(self, timeout=10):
         """Close the connections and network event loop."""
         self.network_event_loop.call_soon_threadsafe(
             self.network_event_loop.stop)
         wait_until(lambda: not self.network_event_loop.is_running(),
                    timeout=timeout)
         self.network_event_loop.close()
         self.join(timeout)
 
 
 class P2PDataStore(P2PInterface):
     """A P2P data store class.
 
     Keeps a block and transaction store and responds correctly to getdata and getheaders requests."""
 
     def __init__(self):
         super().__init__()
         # store of blocks. key is block hash, value is a CBlock object
         self.block_store = {}
         self.last_block_hash = ''
         # store of txs. key is txid, value is a CTransaction object
         self.tx_store = {}
         self.getdata_requests = []
 
     def on_getdata(self, message):
         """Check for the tx/block in our stores and if found, reply with an inv message."""
         for inv in message.inv:
             self.getdata_requests.append(inv.hash)
             if (inv.type & MSG_TYPE_MASK) == MSG_TX and inv.hash in self.tx_store.keys():
                 self.send_message(msg_tx(self.tx_store[inv.hash]))
             elif (inv.type & MSG_TYPE_MASK) == MSG_BLOCK and inv.hash in self.block_store.keys():
                 self.send_message(msg_block(self.block_store[inv.hash]))
             else:
                 logger.debug(
                     'getdata message type {} received.'.format(hex(inv.type)))
 
     def on_getheaders(self, message):
         """Search back through our block store for the locator, and reply with a headers message if found."""
 
         locator, hash_stop = message.locator, message.hashstop
 
         # Assume that the most recent block added is the tip
         if not self.block_store:
             return
 
         headers_list = [self.block_store[self.last_block_hash]]
         maxheaders = 2000
         while headers_list[-1].sha256 not in locator.vHave:
             # Walk back through the block store, adding headers to headers_list
             # as we go.
             prev_block_hash = headers_list[-1].hashPrevBlock
             if prev_block_hash in self.block_store:
                 prev_block_header = CBlockHeader(
                     self.block_store[prev_block_hash])
                 headers_list.append(prev_block_header)
                 if prev_block_header.sha256 == hash_stop:
                     # if this is the hashstop header, stop here
                     break
             else:
                 logger.debug('block hash {} not found in block store'.format(
                     hex(prev_block_hash)))
                 break
 
         # Truncate the list if there are too many headers
         headers_list = headers_list[:-maxheaders - 1:-1]
         response = msg_headers(headers_list)
 
         if response is not None:
             self.send_message(response)
 
     def send_blocks_and_test(self, blocks, node, *, success=True, request_block=True,
                              reject_reason=None, expect_disconnect=False, timeout=60):
         """Send blocks to test node and test whether the tip advances.
 
          - add all blocks to our block_store
          - send a headers message for the final block
          - the on_getheaders handler will ensure that any getheaders are responded to
          - if request_block is True: wait for getdata for each of the blocks. The on_getdata handler will
            ensure that any getdata messages are responded to
          - if success is True: assert that the node's tip advances to the most recent block
          - if success is False: assert that the node's tip doesn't advance
          - if reject_reason is set: assert that the correct reject message is logged"""
 
         with mininode_lock:
             for block in blocks:
                 self.block_store[block.sha256] = block
                 self.last_block_hash = block.sha256
 
         reject_reason = [reject_reason] if reject_reason else []
         with node.assert_debug_log(expected_msgs=reject_reason):
             self.send_message(msg_headers([CBlockHeader(blocks[-1])]))
 
             if request_block:
                 wait_until(
                     lambda: blocks[-1].sha256 in self.getdata_requests, timeout=timeout, lock=mininode_lock)
 
             if expect_disconnect:
                 self.wait_for_disconnect()
             else:
                 self.sync_with_ping()
 
             if success:
                 wait_until(lambda: node.getbestblockhash()
                            == blocks[-1].hash, timeout=timeout)
             else:
                 assert node.getbestblockhash() != blocks[-1].hash
 
     def send_txs_and_test(self, txs, node, *, success=True,
                           expect_disconnect=False, reject_reason=None):
         """Send txs to test node and test whether they're accepted to the mempool.
 
          - add all txs to our tx_store
          - send tx messages for all txs
          - if success is True/False: assert that the txs are/are not accepted to the mempool
          - if expect_disconnect is True: Skip the sync with ping
          - if reject_reason is set: assert that the correct reject message is logged."""
 
         with mininode_lock:
             for tx in txs:
                 self.tx_store[tx.sha256] = tx
 
         reject_reason = [reject_reason] if reject_reason else []
         with node.assert_debug_log(expected_msgs=reject_reason):
             for tx in txs:
                 self.send_message(msg_tx(tx))
 
             if expect_disconnect:
                 self.wait_for_disconnect()
             else:
                 self.sync_with_ping()
 
             raw_mempool = node.getrawmempool()
             if success:
                 # Check that all txs are now in the mempool
                 for tx in txs:
                     assert tx.hash in raw_mempool, "{} not found in mempool".format(
                         tx.hash)
             else:
                 # Check that none of the txs are now in the mempool
                 for tx in txs:
                     assert tx.hash not in raw_mempool, "{} tx found in mempool".format(
                         tx.hash)