From c4491309dc634d82a3ccebb5235119d76c1681bf Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kittywhiskers@users.noreply.github.com>
Date: Sun, 27 Feb 2022 23:43:18 +0530
Subject: [PATCH] merge bitcoin#18029: Add fuzzing harness for AS-mapping
 (asmap)

---
 src/Makefile.test.include |  7 +++++++
 src/netaddress.h          |  1 -
 src/test/fuzz/asmap.cpp   | 28 ++++++++++++++++++++++++++++
 test/fuzz/test_runner.py  |  1 +
 4 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 src/test/fuzz/asmap.cpp

diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index f2743ff332..359dd4c839 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -8,6 +8,7 @@ FUZZ_TARGETS = \
   test/fuzz/addr_info_deserialize \
   test/fuzz/address_deserialize \
   test/fuzz/addrman_deserialize \
+  test/fuzz/asmap \
   test/fuzz/banentry_deserialize \
   test/fuzz/base_encode_decode \
   test/fuzz/bech32 \
@@ -285,6 +286,12 @@ test_fuzz_addrman_deserialize_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 test_fuzz_addrman_deserialize_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(LDFLAGS_WRAP_EXCEPTIONS)
 test_fuzz_addrman_deserialize_LDADD = $(FUZZ_SUITE_LD_COMMON)
 
+test_fuzz_asmap_SOURCES = $(FUZZ_SUITE) test/fuzz/asmap.cpp
+test_fuzz_asmap_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_asmap_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_asmap_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(LDFLAGS_WRAP_EXCEPTIONS)
+test_fuzz_asmap_LDADD = $(FUZZ_SUITE_LD_COMMON)
+
 test_fuzz_blockheader_deserialize_SOURCES = $(FUZZ_SUITE) test/fuzz/deserialize.cpp
 test_fuzz_blockheader_deserialize_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) -DBLOCKHEADER_DESERIALIZE=1
 test_fuzz_blockheader_deserialize_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
diff --git a/src/netaddress.h b/src/netaddress.h
index 7347f4be8d..68420c84a5 100644
--- a/src/netaddress.h
+++ b/src/netaddress.h
@@ -146,7 +146,6 @@ class CNetAddr
          */
         void SetLegacyIPv6(Span<const uint8_t> ipv6);
 
-    private:
         /**
          * Set raw IPv4 or IPv6 address (in network byte order)
          * @note Only NET_IPV4 and NET_IPV6 are allowed for network.
diff --git a/src/test/fuzz/asmap.cpp b/src/test/fuzz/asmap.cpp
new file mode 100644
index 0000000000..7f3eef79a1
--- /dev/null
+++ b/src/test/fuzz/asmap.cpp
@@ -0,0 +1,28 @@
+// 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 <netaddress.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+
+#include <cstdint>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+    const Network network = fuzzed_data_provider.PickValueInArray({NET_IPV4, NET_IPV6});
+    if (fuzzed_data_provider.remaining_bytes() < 16) {
+        return;
+    }
+    CNetAddr net_addr;
+    net_addr.SetRaw(network, fuzzed_data_provider.ConsumeBytes<uint8_t>(16).data());
+    std::vector<bool> asmap;
+    for (const char cur_byte : fuzzed_data_provider.ConsumeRemainingBytes<char>()) {
+        for (int bit = 0; bit < 8; ++bit) {
+            asmap.push_back((cur_byte >> bit) & 1);
+        }
+    }
+    (void)net_addr.GetMappedAS(asmap);
+}
diff --git a/test/fuzz/test_runner.py b/test/fuzz/test_runner.py
index b6e63260f5..e1a2e2be54 100755
--- a/test/fuzz/test_runner.py
+++ b/test/fuzz/test_runner.py
@@ -15,6 +15,7 @@ import logging
 # Fuzzers known to lack a seed corpus in https://github.com/bitcoin-core/qa-assets/tree/master/fuzz_seed_corpus
 FUZZERS_MISSING_CORPORA = [
     "addr_info_deserialize",
+    "asmap",
     "base_encode_decode",
     "block",
     "block_file_info_deserialize",