1  // Copyright (c) 2020 The Bitcoin Core developers
 2  // Distributed under the MIT software license, see the accompanying
 3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 4  
 5  #include <key.h>
 6  #include <secp256k1.h>
 7  #include <test/fuzz/FuzzedDataProvider.h>
 8  #include <test/fuzz/fuzz.h>
 9  #include <test/fuzz/util.h>
10  
11  #include <cstdint>
12  #include <vector>
13  
14  bool SigHasLowR(const secp256k1_ecdsa_signature* sig);
15  int ecdsa_signature_parse_der_lax(secp256k1_ecdsa_signature* sig, const unsigned char* input, size_t inputlen);
16  
17  FUZZ_TARGET(secp256k1_ecdsa_signature_parse_der_lax)
18  {
19      FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
20      const std::vector<uint8_t> signature_bytes = ConsumeRandomLengthByteVector(fuzzed_data_provider);
21      if (signature_bytes.data() == nullptr) {
22          return;
23      }
24      secp256k1_ecdsa_signature sig_der_lax;
25      const bool parsed_der_lax = ecdsa_signature_parse_der_lax(&sig_der_lax, signature_bytes.data(), signature_bytes.size()) == 1;
26      if (parsed_der_lax) {
27          ECC_Start();
28          (void)SigHasLowR(&sig_der_lax);
29          ECC_Stop();
30      }
31  }