Merge #17076: tests: Add fuzzing harness for CheckTransaction(...), IsStandardTx(...) and other CTransaction related functions

5c2987636f tests: Remove TRANSACTION_DESERIALIZE (replaced by transaction fuzzer) (practicalswift)
0a573682f2 tests: Add fuzzing harness for CheckTransaction(...), IsStandardTx(...) and other CTransaction related functions (practicalswift)

Pull request description:

  Add fuzzing harness for `CheckTransaction(...)`, `IsStandardTx(...)` and other `CTransaction` related functions.

  **Testing this PR**

  Run:

  ```
  $ CC=clang CXX=clang++ ./configure --enable-fuzz --with-sanitizers=address,fuzzer,undefined
  $ make
  $ src/test/fuzz/transaction
  …
  # And to to quickly verify that the relevant code regions are triggered, that the
  # fuzzing throughput seems reasonable, etc.
  $ contrib/devtools/test_fuzzing_harnesses.sh '^transaction$'
  ```

  `test_fuzzing_harnesses.sh` can be found in PR #17000.

ACKs for top commit:
  MarcoFalke:
    ACK 5c2987636f

Tree-SHA512: 2f422df795c9dca13c98209ca9ce0fe5a0d4a71fb052fa33d599cc9c9f1d637fee27d58d02ed17b956b3e3d40931cbc1367fc99aa2e882473e54d95dee04d6b7

src/test/fuzz/deserialize.cpp

@@ -40,11 +40,6 @@ void test_one_input(const std::vector<uint8_t>& buffer)
                 CBlock block;
                 ds >> block;
             } catch (const std::ios_base::failure& e) {return;}
-#elif TRANSACTION_DESERIALIZE
-            try
-            {
-                CTransaction tx(deserialize, ds);
-            } catch (const std::ios_base::failure& e) {return;}
 #elif BLOCKLOCATOR_DESERIALIZE
             try
             {

src/test/fuzz/transaction.cpp

@@ -0,0 +1,81 @@
+// 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 <coins.h>
+#include <consensus/tx_check.h>
+#include <consensus/tx_verify.h>
+#include <consensus/validation.h>
+#include <core_io.h>
+#include <core_memusage.h>
+#include <policy/policy.h>
+#include <policy/settings.h>
+#include <primitives/transaction.h>
+#include <streams.h>
+#include <test/fuzz/fuzz.h>
+#include <util/rbf.h>
+#include <validation.h>
+#include <version.h>
+
+#include <cassert>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    CDataStream ds(buffer, SER_NETWORK, INIT_PROTO_VERSION);
+    try {
+        int nVersion;
+        ds >> nVersion;
+        ds.SetVersion(nVersion);
+    } catch (const std::ios_base::failure& e) {
+        return;
+    }
+    bool valid = true;
+    const CTransaction tx = [&] {
+        try {
+            return CTransaction(deserialize, ds);
+        } catch (const std::ios_base::failure& e) {
+            valid = false;
+            return CTransaction();
+        }
+    }();
+    if (!valid) {
+        return;
+    }
+
+    CValidationState state_with_dupe_check;
+    const bool valid_with_dupe_check = CheckTransaction(tx, state_with_dupe_check, /* fCheckDuplicateInputs= */ true);
+    CValidationState state_without_dupe_check;
+    const bool valid_without_dupe_check = CheckTransaction(tx, state_without_dupe_check, /* fCheckDuplicateInputs= */ false);
+    if (valid_with_dupe_check) {
+        assert(valid_without_dupe_check);
+    }
+
+    const CFeeRate dust_relay_fee{DUST_RELAY_TX_FEE};
+    std::string reason;
+    const bool is_standard_with_permit_bare_multisig = IsStandardTx(tx, /* permit_bare_multisig= */ true, dust_relay_fee, reason);
+    const bool is_standard_without_permit_bare_multisig = IsStandardTx(tx, /* permit_bare_multisig= */ false, dust_relay_fee, reason);
+    if (is_standard_without_permit_bare_multisig) {
+        assert(is_standard_with_permit_bare_multisig);
+    }
+
+    (void)tx.GetHash();
+    (void)tx.GetTotalSize();
+    try {
+        (void)tx.GetValueOut();
+    } catch (const std::runtime_error&) {
+    }
+    (void)tx.GetWitnessHash();
+    (void)tx.HasWitness();
+    (void)tx.IsCoinBase();
+    (void)tx.IsNull();
+    (void)tx.ToString();
+
+    (void)EncodeHexTx(tx);
+    (void)GetLegacySigOpCount(tx);
+    (void)GetTransactionWeight(tx);
+    (void)GetVirtualTransactionSize(tx);
+    (void)IsFinalTx(tx, /* nBlockHeight= */ 1024, /* nBlockTime= */ 1024);
+    (void)IsStandardTx(tx, reason);
+    (void)RecursiveDynamicUsage(tx);
+    (void)SignalsOptInRBF(tx);
+}