merge bitcoin#28419: introduce and use ConsumePrivateKey helper

src/test/fuzz/bip324.cpp

@@ -26,19 +26,13 @@ FUZZ_TARGET_INIT(bip324_cipher_roundtrip, initialize_bip324)
     // Load keys from fuzzer.
     FuzzedDataProvider provider(buffer.data(), buffer.size());
     // Initiator key
-    auto init_key_data = provider.ConsumeBytes<unsigned char>(32);
-    init_key_data.resize(32);
-    CKey init_key;
-    init_key.Set(init_key_data.begin(), init_key_data.end(), true);
+    CKey init_key = ConsumePrivateKey(provider, /*compressed=*/true);
     if (!init_key.IsValid()) return;
     // Initiator entropy
     auto init_ent = provider.ConsumeBytes<std::byte>(32);
     init_ent.resize(32);
     // Responder key
-    auto resp_key_data = provider.ConsumeBytes<unsigned char>(32);
-    resp_key_data.resize(32);
-    CKey resp_key;
-    resp_key.Set(resp_key_data.begin(), resp_key_data.end(), true);
+    CKey resp_key = ConsumePrivateKey(provider, /*compressed=*/true);
     if (!resp_key.IsValid()) return;
     // Responder entropy
     auto resp_ent = provider.ConsumeBytes<std::byte>(32);

src/test/fuzz/key.cpp

@@ -15,6 +15,7 @@
 #include <streams.h>
 #include <test/fuzz/FuzzedDataProvider.h>
 #include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
 #include <util/strencodings.h>
 
 #include <array>
@@ -264,10 +265,7 @@ FUZZ_TARGET_INIT(ellswift_roundtrip, initialize_key)
 {
     FuzzedDataProvider fdp{buffer.data(), buffer.size()};
 
-    auto key_bytes = fdp.ConsumeBytes<uint8_t>(32);
-    key_bytes.resize(32);
-    CKey key;
-    key.Set(key_bytes.begin(), key_bytes.end(), true);
+    CKey key = ConsumePrivateKey(fdp, /*compressed=*/true);
     if (!key.IsValid()) return;
 
     auto ent32 = fdp.ConsumeBytes<std::byte>(32);
@@ -284,17 +282,11 @@ FUZZ_TARGET_INIT(bip324_ecdh, initialize_key)
     FuzzedDataProvider fdp{buffer.data(), buffer.size()};
 
     // We generate private key, k1.
-    auto rnd32 = fdp.ConsumeBytes<uint8_t>(32);
-    rnd32.resize(32);
-    CKey k1;
-    k1.Set(rnd32.begin(), rnd32.end(), true);
+    CKey k1 = ConsumePrivateKey(fdp, /*compressed=*/true);
     if (!k1.IsValid()) return;
 
     // They generate private key, k2.
-    rnd32 = fdp.ConsumeBytes<uint8_t>(32);
-    rnd32.resize(32);
-    CKey k2;
-    k2.Set(rnd32.begin(), rnd32.end(), true);
+    CKey k2 = ConsumePrivateKey(fdp, /*compressed=*/true);
     if (!k2.IsValid()) return;
 
     // We construct an ellswift encoding for our key, k1_ellswift.

src/test/fuzz/message.cpp

@@ -27,9 +27,7 @@ FUZZ_TARGET_INIT(message, initialize_message)
     FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
     const std::string random_message = fuzzed_data_provider.ConsumeRandomLengthString(1024);
     {
-        const std::vector<uint8_t> random_bytes = ConsumeRandomLengthByteVector(fuzzed_data_provider);
-        CKey private_key;
-        private_key.Set(random_bytes.begin(), random_bytes.end(), fuzzed_data_provider.ConsumeBool());
+        CKey private_key = ConsumePrivateKey(fuzzed_data_provider);
         std::string signature;
         const bool message_signed = MessageSign(private_key, random_message, signature);
         if (private_key.IsValid()) {

src/test/fuzz/rpc.cpp

@@ -274,9 +274,7 @@ std::string ConsumeScalarRPCArgument(FuzzedDataProvider& fuzzed_data_provider)
         },
         [&] {
             // base58 encoded key
-            const std::vector<uint8_t> random_bytes = fuzzed_data_provider.ConsumeBytes<uint8_t>(32);
-            CKey key;
-            key.Set(random_bytes.begin(), random_bytes.end(), fuzzed_data_provider.ConsumeBool());
+            CKey key = ConsumePrivateKey(fuzzed_data_provider);
             if (!key.IsValid()) {
                 return;
             }
@@ -284,9 +282,7 @@ std::string ConsumeScalarRPCArgument(FuzzedDataProvider& fuzzed_data_provider)
         },
         [&] {
             // hex encoded pubkey
-            const std::vector<uint8_t> random_bytes = fuzzed_data_provider.ConsumeBytes<uint8_t>(32);
-            CKey key;
-            key.Set(random_bytes.begin(), random_bytes.end(), fuzzed_data_provider.ConsumeBool());
+            CKey key = ConsumePrivateKey(fuzzed_data_provider);
             if (!key.IsValid()) {
                 return;
             }

src/test/fuzz/script_sign.cpp

@@ -78,9 +78,7 @@ FUZZ_TARGET_INIT(script_sign, initialize_script_sign)
     }
 
     FillableSigningProvider provider;
-    CKey k;
-    const std::vector<uint8_t> key_data = ConsumeRandomLengthByteVector(fuzzed_data_provider);
-    k.Set(key_data.begin(), key_data.end(), fuzzed_data_provider.ConsumeBool());
+    CKey k = ConsumePrivateKey(fuzzed_data_provider);
     if (k.IsValid()) {
         provider.AddKey(k);
     }

src/test/fuzz/util.cpp

@@ -351,3 +351,13 @@ uint32_t ConsumeSequence(FuzzedDataProvider& fuzzed_data_provider) noexcept
                }) :
                fuzzed_data_provider.ConsumeIntegral<uint32_t>();
 }
+
+CKey ConsumePrivateKey(FuzzedDataProvider& fuzzed_data_provider, std::optional<bool> compressed) noexcept
+{
+    auto key_data = fuzzed_data_provider.ConsumeBytes<uint8_t>(32);
+    key_data.resize(32);
+    CKey key;
+    bool compressed_value = compressed ? *compressed : fuzzed_data_provider.ConsumeBool();
+    key.Set(key_data.begin(), key_data.end(), compressed_value);
+    return key;
+}

src/test/fuzz/util.h

@@ -12,6 +12,7 @@
 #include <coins.h>
 #include <compat.h>
 #include <consensus/consensus.h>
+#include <key.h>
 #include <merkleblock.h>
 #include <net.h>
 #include <netaddress.h>
@@ -250,6 +251,8 @@ template <typename WeakEnumType, size_t size>
     return tx_destination;
 }
 
+[[nodiscard]] CKey ConsumePrivateKey(FuzzedDataProvider& fuzzed_data_provider, std::optional<bool> compressed = std::nullopt) noexcept;
+
 template <typename T>
 [[nodiscard]] bool MultiplicationOverflow(const T i, const T j) noexcept
 {