Merge #18994: tests: Add fuzzing harnesses for functions in script/

f898ef65c947776750e49d050633f830546bbdc6 tests: Add fuzzing harness for functions in script/sign.h (practicalswift)
c91d2f06150cda258a17e78d9b7065b594d34a85 tests: Add fuzzing harness for functions in script/sigcache.h (practicalswift)
d3d8adb79fbe34b15cf29334607f9b76d303aa1a tests: Add fuzzing harness for functions in script/interpreter.h (practicalswift)
fa80117cfdeca7e5d3a2a09b385c0e938bf701e9 tests: Add fuzzing harness for functions in script/descriptor.h (practicalswift)
43fb8f0ca331a7f79f0d287817da7f4b894bdbfa tests: Add fuzzing harness for functions in script/bitcoinconsensus.h (practicalswift)
8de72711c685e638fa54d485694fb1b1af024adc tests: Fill fuzzing coverage gaps for functions in script/script.h, script/script_error.h and script/standard.h (practicalswift)
c571ecb07145b4ce8c17ca80489f8f1497388c4d tests: Add fuzzing helper functions ConsumeDataStream, ConsumeTxDestination and ConsumeUInt160 (practicalswift)

Pull request description:

  Add fuzzing harnesses for functions in `script/`:
  * Add fuzzing helper functions `ConsumeDataStream` and `ConsumeUInt160`
  * Fill fuzzing coverage gaps for functions in `script/script.h`, `script/script_error.h` and `script/standard.h`
  * Add fuzzing harness for functions in `script/bitcoinconsensus.h`
  * Add fuzzing harness for functions in `script/descriptor.h`
  * Add fuzzing harness for functions in `script/interpreter.h`
  * Add fuzzing harness for functions in `script/sigcache.h`
  * Add fuzzing harness for functions in `script/sign.h`

  See [`doc/fuzzing.md`](https://github.com/bitcoin/bitcoin/blob/master/doc/fuzzing.md) for information on how to fuzz Bitcoin Core. Don't forget to contribute any coverage increasing inputs you find to the [Bitcoin Core fuzzing corpus repo](https://github.com/bitcoin-core/qa-assets).

  Happy fuzzing :)

ACKs for top commit:
  MarcoFalke:
    ACK f898ef65c947776750e49d050633f830546bbdc6 🔉

Tree-SHA512: f6e77b34dc79f23de5fa9e38ac06e6554b5b946ec3e9a67e2bd982e60aca37ce844f785457ef427a5e3b45e31c305456bca8587cc9f4a0b50b3852e39726eb04

1 files changed, 45 insertions, 0 deletions

diff --git a/src/test/fuzz/script_sigcache.cpp b/src/test/fuzz/script_sigcache.cpp
new file mode 100644
index 000000000..434a47b70
--- /dev/null
+++ b/src/test/fuzz/script_sigcache.cpp
@@ -0,0 +1,45 @@
+// 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 <chainparams.h>
+#include <chainparamsbase.h>
+#include <key.h>
+#include <pubkey.h>
+#include <script/sigcache.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <vector>
+
+void initialize()
+{
+    static const ECCVerifyHandle ecc_verify_handle;
+    ECC_Start();
+    SelectParams(CBaseChainParams::REGTEST);
+    InitSignatureCache();
+}
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+
+    const std::optional<CMutableTransaction> mutable_transaction = ConsumeDeserializable<CMutableTransaction>(fuzzed_data_provider);
+    const CTransaction tx = mutable_transaction ? CTransaction{*mutable_transaction} : CTransaction{};
+    const unsigned int n_in = fuzzed_data_provider.ConsumeIntegral<unsigned int>();
+    const CAmount amount = ConsumeMoney(fuzzed_data_provider);
+    const bool store = fuzzed_data_provider.ConsumeBool();
+    PrecomputedTransactionData tx_data;
+    CachingTransactionSignatureChecker caching_transaction_signature_checker{mutable_transaction ? &tx : nullptr, n_in, amount, store, tx_data};
+    const std::optional<CPubKey> pub_key = ConsumeDeserializable<CPubKey>(fuzzed_data_provider);
+    if (pub_key) {
+        const std::vector<uint8_t> random_bytes = ConsumeRandomLengthByteVector(fuzzed_data_provider);
+        if (!random_bytes.empty()) {
+            (void)caching_transaction_signature_checker.VerifySignature(random_bytes, *pub_key, ConsumeUInt256(fuzzed_data_provider));
+        }
+    }
+}