tests: Add fuzzing harness for ProcessMessage(...)

4 files changed, 109 insertions, 2 deletions

diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index c9beb91a42..02743a2e06 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -53,6 +53,7 @@ FUZZ_TARGETS = \
   test/fuzz/partial_merkle_tree_deserialize \
   test/fuzz/partially_signed_transaction_deserialize \
   test/fuzz/prefilled_transaction_deserialize \
+  test/fuzz/process_message \
   test/fuzz/psbt \
   test/fuzz/psbt_input_deserialize \
   test/fuzz/psbt_output_deserialize \
@@ -542,6 +543,12 @@ test_fuzz_prefilled_transaction_deserialize_LDADD = $(FUZZ_SUITE_LD_COMMON)
 test_fuzz_prefilled_transaction_deserialize_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 test_fuzz_prefilled_transaction_deserialize_SOURCES = $(FUZZ_SUITE) test/fuzz/deserialize.cpp
 
+test_fuzz_process_message_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_process_message_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_process_message_LDADD = $(FUZZ_SUITE_LD_COMMON)
+test_fuzz_process_message_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+test_fuzz_process_message_SOURCES = $(FUZZ_SUITE) test/fuzz/process_message.cpp
+
 test_fuzz_psbt_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 test_fuzz_psbt_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 test_fuzz_psbt_LDADD = $(FUZZ_SUITE_LD_COMMON)
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index fa09b60630..e4df9fb90e 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1908,7 +1908,7 @@ void static ProcessOrphanTx(CConnman* connman, std::set<uint256>& orphan_work_se
     }
 }
 
-bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, BanMan* banman, const std::atomic<bool>& interruptMsgProc)
+bool ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, BanMan* banman, const std::atomic<bool>& interruptMsgProc)
 {
     LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n", SanitizeString(strCommand), vRecv.size(), pfrom->GetId());
     if (gArgs.IsArgSet("-dropmessagestest") && GetRand(gArgs.GetArg("-dropmessagestest", 0)) == 0)
diff --git a/src/test/fuzz/process_message.cpp b/src/test/fuzz/process_message.cpp
new file mode 100644
index 0000000000..934f741068
--- /dev/null
+++ b/src/test/fuzz/process_message.cpp
@@ -0,0 +1,98 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <banman.h>
+#include <chainparams.h>
+#include <consensus/consensus.h>
+#include <net.h>
+#include <net_processing.h>
+#include <protocol.h>
+#include <scheduler.h>
+#include <script/script.h>
+#include <streams.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/util/mining.h>
+#include <test/util/setup_common.h>
+#include <util/memory.h>
+#include <validationinterface.h>
+#include <version.h>
+
+#include <algorithm>
+#include <atomic>
+#include <cassert>
+#include <chrono>
+#include <cstdint>
+#include <iosfwd>
+#include <iostream>
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <vector>
+
+bool ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, BanMan* banman, const std::atomic<bool>& interruptMsgProc);
+
+namespace {
+
+#ifdef MESSAGE_TYPE
+#define TO_STRING_(s) #s
+#define TO_STRING(s) TO_STRING_(s)
+const std::string LIMIT_TO_MESSAGE_TYPE{TO_STRING(MESSAGE_TYPE)};
+#else
+const std::string LIMIT_TO_MESSAGE_TYPE;
+#endif
+
+const std::map<std::string, std::set<std::string>> EXPECTED_DESERIALIZATION_EXCEPTIONS = {
+    {"CDataStream::read(): end of data: iostream error", {"addr", "block", "blocktxn", "cmpctblock", "feefilter", "filteradd", "filterload", "getblocks", "getblocktxn", "getdata", "getheaders", "headers", "inv", "notfound", "ping", "sendcmpct", "tx"}},
+    {"CompactSize exceeds limit of type: iostream error", {"cmpctblock"}},
+    {"differential value overflow: iostream error", {"getblocktxn"}},
+    {"index overflowed 16 bits: iostream error", {"getblocktxn"}},
+    {"index overflowed 16-bits: iostream error", {"cmpctblock"}},
+    {"indexes overflowed 16 bits: iostream error", {"getblocktxn"}},
+    {"non-canonical ReadCompactSize(): iostream error", {"addr", "block", "blocktxn", "cmpctblock", "filteradd", "filterload", "getblocks", "getblocktxn", "getdata", "getheaders", "headers", "inv", "notfound", "tx"}},
+    {"ReadCompactSize(): size too large: iostream error", {"addr", "block", "blocktxn", "cmpctblock", "filteradd", "filterload", "getblocks", "getblocktxn", "getdata", "getheaders", "headers", "inv", "notfound", "tx"}},
+    {"Superfluous witness record: iostream error", {"block", "blocktxn", "cmpctblock", "tx"}},
+    {"Unknown transaction optional data: iostream error", {"block", "blocktxn", "cmpctblock", "tx"}},
+};
+
+const RegTestingSetup* g_setup;
+} // namespace
+
+void initialize()
+{
+    static RegTestingSetup setup{};
+    g_setup = &setup;
+
+    for (int i = 0; i < 2 * COINBASE_MATURITY; i++) {
+        MineBlock(g_setup->m_node, CScript() << OP_TRUE);
+    }
+    SyncWithValidationInterfaceQueue();
+}
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+    const std::string random_message_type{fuzzed_data_provider.ConsumeBytesAsString(CMessageHeader::COMMAND_SIZE).c_str()};
+    if (!LIMIT_TO_MESSAGE_TYPE.empty() && random_message_type != LIMIT_TO_MESSAGE_TYPE) {
+        return;
+    }
+    CDataStream random_bytes_data_stream{fuzzed_data_provider.ConsumeRemainingBytes<unsigned char>(), SER_NETWORK, PROTOCOL_VERSION};
+    CNode p2p_node{0, ServiceFlags(NODE_NETWORK | NODE_WITNESS | NODE_BLOOM), 0, INVALID_SOCKET, CAddress{CService{in_addr{0x0100007f}, 7777}, NODE_NETWORK}, 0, 0, CAddress{}, std::string{}, false};
+    p2p_node.fSuccessfullyConnected = true;
+    p2p_node.nVersion = PROTOCOL_VERSION;
+    p2p_node.SetSendVersion(PROTOCOL_VERSION);
+    g_setup->m_node.peer_logic->InitializeNode(&p2p_node);
+    try {
+        (void)ProcessMessage(&p2p_node, random_message_type, random_bytes_data_stream, GetTimeMillis(), Params(), g_setup->m_node.connman.get(), g_setup->m_node.banman.get(), std::atomic<bool>{false});
+    } catch (const std::ios_base::failure& e) {
+        const std::string exception_message{e.what()};
+        const auto p = EXPECTED_DESERIALIZATION_EXCEPTIONS.find(exception_message);
+        if (p == EXPECTED_DESERIALIZATION_EXCEPTIONS.cend() || p->second.count(random_message_type) == 0) {
+            std::cout << "Unexpected exception when processing message type \"" << random_message_type << "\": " << exception_message << std::endl;
+            assert(false);
+        }
+    }
+    SyncWithValidationInterfaceQueue();
+}
diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index 53eb9ff43b..ad3ff48860 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -13,6 +13,7 @@
 #include <init.h>
 #include <miner.h>
 #include <net.h>
+#include <net_processing.h>
 #include <noui.h>
 #include <pow.h>
 #include <rpc/blockchain.h>
@@ -62,7 +63,7 @@ std::ostream& operator<<(std::ostream& os, const uint256& num)
 }
 
 BasicTestingSetup::BasicTestingSetup(const std::string& chainName)
-    : m_path_root{fs::temp_directory_path() / "test_common_" PACKAGE_NAME / std::to_string(g_insecure_rand_ctx_temp_path.rand32())}
+    : m_path_root{fs::temp_directory_path() / "test_common_" PACKAGE_NAME / g_insecure_rand_ctx_temp_path.rand256().ToString()}
 {
     fs::create_directories(m_path_root);
     gArgs.ForceSetArg("-datadir", m_path_root.string());
@@ -136,6 +137,7 @@ TestingSetup::TestingSetup(const std::string& chainName) : BasicTestingSetup(cha
     m_node.mempool->setSanityCheck(1.0);
     m_node.banman = MakeUnique<BanMan>(GetDataDir() / "banlist.dat", nullptr, DEFAULT_MISBEHAVING_BANTIME);
     m_node.connman = MakeUnique<CConnman>(0x1337, 0x1337); // Deterministic randomness for tests.
+    m_node.peer_logic = MakeUnique<PeerLogicValidation>(m_node.connman.get(), m_node.banman.get(), *m_node.scheduler);
 }
 
 TestingSetup::~TestingSetup()