tests: Add ParseHDKeypath(...) (bip32) fuzzing harness

src/Makefile.test.include

@@ -33,6 +33,7 @@ FUZZ_TARGETS = \
   test/fuzz/messageheader_deserialize \
   test/fuzz/netaddr_deserialize \
   test/fuzz/out_point_deserialize \
+  test/fuzz/parse_hd_keypath \
   test/fuzz/parse_iso8601 \
   test/fuzz/partial_merkle_tree_deserialize \
   test/fuzz/partially_signed_transaction_deserialize \
@@ -518,6 +519,12 @@ test_fuzz_tx_out_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 test_fuzz_tx_out_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 test_fuzz_tx_out_LDADD = $(FUZZ_SUITE_LD_COMMON)
 
+test_fuzz_parse_hd_keypath_SOURCES = $(FUZZ_SUITE) test/fuzz/parse_hd_keypath.cpp
+test_fuzz_parse_hd_keypath_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_parse_hd_keypath_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_parse_hd_keypath_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+test_fuzz_parse_hd_keypath_LDADD = $(FUZZ_SUITE_LD_COMMON)
+
 endif # ENABLE_FUZZ
 
 nodist_test_test_bitcoin_SOURCES = $(GENERATED_TEST_FILES)

src/test/fuzz/parse_hd_keypath.cpp

@@ -0,0 +1,13 @@
+// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/fuzz/fuzz.h>
+#include <util/bip32.h>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    const std::string keypath_str(buffer.begin(), buffer.end());
+    std::vector<uint32_t> keypath;
+    (void)ParseHDKeypath(keypath_str, keypath);
+}