tests: Add fuzzing harness for poly1305_auth(...)

Author: practicalswift

src/Makefile.test.include

@@ -36,6 +36,7 @@ FUZZ_TARGETS = \
   test/fuzz/crypto_aes256 \
   test/fuzz/crypto_aes256cbc \
   test/fuzz/crypto_common \
+  test/fuzz/crypto_poly1305 \
   test/fuzz/cuckoocache \
   test/fuzz/decode_tx \
   test/fuzz/descriptor_parse \
@@ -506,6 +507,12 @@ test_fuzz_crypto_common_LDADD = $(FUZZ_SUITE_LD_COMMON)
 test_fuzz_crypto_common_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 test_fuzz_crypto_common_SOURCES = test/fuzz/crypto_common.cpp
 
+test_fuzz_crypto_poly1305_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_crypto_poly1305_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_crypto_poly1305_LDADD = $(FUZZ_SUITE_LD_COMMON)
+test_fuzz_crypto_poly1305_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+test_fuzz_crypto_poly1305_SOURCES = test/fuzz/crypto_poly1305.cpp
+
 test_fuzz_cuckoocache_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 test_fuzz_cuckoocache_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 test_fuzz_cuckoocache_LDADD = $(FUZZ_SUITE_LD_COMMON)

src/test/fuzz/crypto_poly1305.cpp

@@ -0,0 +1,22 @@
+// 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 <crypto/poly1305.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cstdint>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
+
+    const std::vector<uint8_t> key = ConsumeFixedLengthByteVector(fuzzed_data_provider, POLY1305_KEYLEN);
+    const std::vector<uint8_t> in = ConsumeRandomLengthByteVector(fuzzed_data_provider);
+
+    std::vector<uint8_t> tag_out(POLY1305_TAGLEN);
+    poly1305_auth(tag_out.data(), in.data(), in.size(), key.data());
+}