tests: Add fuzzing harness for CheckBlock(...) and other CBlock related functions

src/test/fuzz/block.cpp

@@ -0,0 +1,63 @@
+// Copyright (c) 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 <chainparams.h>
+#include <consensus/merkle.h>
+#include <consensus/validation.h>
+#include <core_io.h>
+#include <core_memusage.h>
+#include <pubkey.h>
+#include <primitives/block.h>
+#include <streams.h>
+#include <test/fuzz/fuzz.h>
+#include <validation.h>
+#include <version.h>
+
+#include <cassert>
+#include <string>
+
+void initialize()
+{
+    const static auto verify_handle = MakeUnique<ECCVerifyHandle>();
+    SelectParams(CBaseChainParams::REGTEST);
+}
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    CDataStream ds(buffer, SER_NETWORK, INIT_PROTO_VERSION);
+    CBlock block;
+    try {
+        int nVersion;
+        ds >> nVersion;
+        ds.SetVersion(nVersion);
+        ds >> block;
+    } catch (const std::ios_base::failure&) {
+        return;
+    }
+    const Consensus::Params& consensus_params = Params().GetConsensus();
+    BlockValidationState validation_state_pow_and_merkle;
+    const bool valid_incl_pow_and_merkle = CheckBlock(block, validation_state_pow_and_merkle, consensus_params, /* fCheckPOW= */ true, /* fCheckMerkleRoot= */ true);
+    BlockValidationState validation_state_pow;
+    const bool valid_incl_pow = CheckBlock(block, validation_state_pow, consensus_params, /* fCheckPOW= */ true, /* fCheckMerkleRoot= */ false);
+    BlockValidationState validation_state_merkle;
+    const bool valid_incl_merkle = CheckBlock(block, validation_state_merkle, consensus_params, /* fCheckPOW= */ false, /* fCheckMerkleRoot= */ true);
+    BlockValidationState validation_state_none;
+    const bool valid_incl_none = CheckBlock(block, validation_state_none, consensus_params, /* fCheckPOW= */ false, /* fCheckMerkleRoot= */ false);
+    if (valid_incl_pow_and_merkle) {
+        assert(valid_incl_pow && valid_incl_merkle && valid_incl_none);
+    } else if (valid_incl_merkle || valid_incl_pow) {
+        assert(valid_incl_none);
+    }
+    (void)block.GetHash();
+    (void)block.ToString();
+    (void)BlockMerkleRoot(block);
+    if (!block.vtx.empty()) {
+        // TODO: Avoid array index out of bounds error in BlockWitnessMerkleRoot
+        //       when block.vtx.empty().
+        (void)BlockWitnessMerkleRoot(block);
+    }
+    (void)GetBlockWeight(block);
+    (void)GetWitnessCommitmentIndex(block);
+    (void)RecursiveDynamicUsage(block);
+}