Change in reference implementation

Co-authored-by: Ruhi <44024636+stratospher@users.noreply.github.com>

src/Makefile.test.include

@@ -230,6 +230,7 @@ test_fuzz_fuzz_SOURCES = \
  test/fuzz/crypto_chacha20.cpp \
  test/fuzz/crypto_chacha20_poly1305_aead.cpp \
  test/fuzz/crypto_common.cpp \
+ test/fuzz/crypto_diff_fuzz_poly1305.cpp \
  test/fuzz/crypto_hkdf_hmac_sha256_l32.cpp \
  test/fuzz/crypto_poly1305.cpp \
  test/fuzz/cuckoocache.cpp \

src/test/fuzz/crypto_diff_fuzz_poly1305.cpp

@@ -22,7 +22,11 @@ static INLINE void fU32TO8_LE_FAST(uint8_t* p, const uint32_t v) { *(uint32_t*)p
 #define U8TO32_LE(p) fU8TO32_LE_FAST(p)
 #define U32TO8_LE(p, v) fU32TO8_LE_FAST(p, v)
 
-void poly1305_auth(unsigned char out[16], const unsigned char* m, size_t inlen, const unsigned char key[32])
+/*
+Same function name in both bitcoin core implementation and floodyberry's implementation
+So changing the function name "poly1305_auth" to "poly1305_auth_floodyberry" in reference implementation
+*/
+void poly1305_auth_floodyberry(unsigned char out[16], const unsigned char* m, size_t inlen, const unsigned char key[32])
 {
     uint32_t t0, t1, t2, t3;
     uint32_t h0, h1, h2, h3, h4;
@@ -189,3 +193,19 @@ void poly1305_auth(unsigned char out[16], const unsigned char* m, size_t inlen,
     f3 += (f2 >> 32);
     U32TO8_LE(&out[12], f3);
 }
+
+FUZZ_TARGET(crypto_diff_fuzz_poly1305)
+{
+    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);
+    std::vector<uint8_t> tag_out_floodyberry(POLY1305_TAGLEN);
+    poly1305_auth(tag_out.data(), in.data(), in.size(), key.data());
+    poly1305_auth_floodyberry(tag_out_floodyberry.data(), in.data(), in.size(), key.data());
+
+    assert(memcmp(tag_out.data(), tag_out_floodyberry.data(), POLY1305_TAGLEN) == 0);
+}
+