util.cpp raw
1 // Copyright (c) 2021-present 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 <consensus/amount.h>
6 #include <pubkey.h>
7 #include <test/fuzz/util.h>
8 #include <test/util/script.h>
9 #include <util/check.h>
10 #include <util/overflow.h>
11 #include <util/rbf.h>
12 #include <util/time.h>
13
14 #include <memory>
15
16 std::vector<uint8_t> ConstructPubKeyBytes(FuzzedDataProvider& fuzzed_data_provider, std::span<const uint8_t> byte_data, const bool compressed) noexcept
17 {
18 uint8_t pk_type;
19 if (compressed) {
20 pk_type = fuzzed_data_provider.PickValueInArray({0x02, 0x03});
21 } else {
22 pk_type = fuzzed_data_provider.PickValueInArray({0x04, 0x06, 0x07});
23 }
24 std::vector<uint8_t> pk_data{byte_data.begin(), byte_data.begin() + (compressed ? CPubKey::COMPRESSED_SIZE : CPubKey::SIZE)};
25 pk_data[0] = pk_type;
26 return pk_data;
27 }
28
29 CAmount ConsumeMoney(FuzzedDataProvider& fuzzed_data_provider, const std::optional<CAmount>& max) noexcept
30 {
31 return fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(0, max.value_or(MAX_MONEY));
32 }
33
34 NodeSeconds ConsumeTime(FuzzedDataProvider& fuzzed_data_provider, const std::optional<int64_t>& min, const std::optional<int64_t>& max) noexcept
35 {
36 // Avoid t=0 (1970-01-01T00:00:00Z) since SetMockTime(0) disables mocktime.
37 static const int64_t time_min{ParseISO8601DateTime("2000-01-01T00:00:01Z").value()};
38 static const int64_t time_max{ParseISO8601DateTime("2100-12-31T23:59:59Z").value()};
39 return NodeSeconds{ConsumeDuration<std::chrono::seconds>(fuzzed_data_provider, min.value_or(time_min) * 1s, max.value_or(time_max) * 1s)};
40 }
41
42 CMutableTransaction ConsumeTransaction(FuzzedDataProvider& fuzzed_data_provider, const std::optional<std::vector<Txid>>& prevout_txids, const int max_num_in, const int max_num_out) noexcept
43 {
44 CMutableTransaction tx_mut;
45 const auto p2wsh_op_true = fuzzed_data_provider.ConsumeBool();
46 tx_mut.version = fuzzed_data_provider.ConsumeBool() ?
47 CTransaction::CURRENT_VERSION :
48 fuzzed_data_provider.ConsumeIntegral<uint32_t>();
49 tx_mut.nLockTime = fuzzed_data_provider.ConsumeIntegral<uint32_t>();
50 const auto num_in = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, max_num_in);
51 const auto num_out = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, max_num_out);
52 for (int i = 0; i < num_in; ++i) {
53 const auto& txid_prev = prevout_txids ?
54 PickValue(fuzzed_data_provider, *prevout_txids) :
55 Txid::FromUint256(ConsumeUInt256(fuzzed_data_provider));
56 const auto index_out = fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(0, max_num_out);
57 const auto sequence = ConsumeSequence(fuzzed_data_provider);
58 const auto script_sig = p2wsh_op_true ? CScript{} : ConsumeScript(fuzzed_data_provider);
59 CScriptWitness script_wit;
60 if (p2wsh_op_true) {
61 script_wit.stack = std::vector<std::vector<uint8_t>>{WITNESS_STACK_ELEM_OP_TRUE};
62 } else {
63 script_wit = ConsumeScriptWitness(fuzzed_data_provider);
64 }
65 CTxIn in;
66 in.prevout = COutPoint{txid_prev, index_out};
67 in.nSequence = sequence;
68 in.scriptSig = script_sig;
69 in.scriptWitness = script_wit;
70
71 tx_mut.vin.push_back(in);
72 }
73 for (int i = 0; i < num_out; ++i) {
74 const auto amount = fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(-10, 50 * COIN + 10);
75 const auto script_pk = p2wsh_op_true ?
76 P2WSH_OP_TRUE :
77 ConsumeScript(fuzzed_data_provider, /*maybe_p2wsh=*/true);
78 tx_mut.vout.emplace_back(amount, script_pk);
79 }
80 return tx_mut;
81 }
82
83 CScriptWitness ConsumeScriptWitness(FuzzedDataProvider& fuzzed_data_provider, const size_t max_stack_elem_size) noexcept
84 {
85 CScriptWitness ret;
86 const auto n_elements = fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, max_stack_elem_size);
87 for (size_t i = 0; i < n_elements; ++i) {
88 ret.stack.push_back(ConsumeRandomLengthByteVector(fuzzed_data_provider));
89 }
90 return ret;
91 }
92
93 CScript ConsumeScript(FuzzedDataProvider& fuzzed_data_provider, const bool maybe_p2wsh) noexcept
94 {
95 CScript r_script{};
96 {
97 // Keep a buffer of bytes to allow the fuzz engine to produce smaller
98 // inputs to generate CScripts with repeated data.
99 static constexpr unsigned MAX_BUFFER_SZ{128};
100 std::vector<uint8_t> buffer(MAX_BUFFER_SZ, uint8_t{'a'});
101 while (fuzzed_data_provider.ConsumeBool()) {
102 CallOneOf(
103 fuzzed_data_provider,
104 [&] {
105 // Insert byte vector directly to allow malformed or unparsable scripts
106 r_script.insert(r_script.end(), buffer.begin(), buffer.begin() + fuzzed_data_provider.ConsumeIntegralInRange(0U, MAX_BUFFER_SZ));
107 },
108 [&] {
109 // Push a byte vector from the buffer
110 r_script << std::vector<uint8_t>{buffer.begin(), buffer.begin() + fuzzed_data_provider.ConsumeIntegralInRange(0U, MAX_BUFFER_SZ)};
111 },
112 [&] {
113 // Push multisig
114 // There is a special case for this to aid the fuzz engine
115 // navigate the highly structured multisig format.
116 r_script << fuzzed_data_provider.ConsumeIntegralInRange<int64_t>(0, 22);
117 int num_data{fuzzed_data_provider.ConsumeIntegralInRange(1, 22)};
118 while (num_data--) {
119 auto pubkey_bytes{ConstructPubKeyBytes(fuzzed_data_provider, buffer, fuzzed_data_provider.ConsumeBool())};
120 if (fuzzed_data_provider.ConsumeBool()) {
121 pubkey_bytes.back() = num_data; // Make each pubkey different
122 }
123 r_script << pubkey_bytes;
124 }
125 r_script << fuzzed_data_provider.ConsumeIntegralInRange<int64_t>(0, 22);
126 },
127 [&] {
128 // Mutate the buffer
129 const auto vec{ConsumeRandomLengthByteVector(fuzzed_data_provider, /*max_length=*/MAX_BUFFER_SZ)};
130 std::copy(vec.begin(), vec.end(), buffer.begin());
131 },
132 [&] {
133 // Push an integral
134 r_script << fuzzed_data_provider.ConsumeIntegral<int64_t>();
135 },
136 [&] {
137 // Push an opcode
138 r_script << ConsumeOpcodeType(fuzzed_data_provider);
139 },
140 [&] {
141 // Push a scriptnum
142 r_script << ConsumeScriptNum(fuzzed_data_provider);
143 });
144 }
145 }
146 if (maybe_p2wsh && fuzzed_data_provider.ConsumeBool()) {
147 uint256 script_hash;
148 CSHA256().Write(r_script.data(), r_script.size()).Finalize(script_hash.begin());
149 r_script.clear();
150 r_script << OP_0 << ToByteVector(script_hash);
151 }
152 return r_script;
153 }
154
155 uint32_t ConsumeSequence(FuzzedDataProvider& fuzzed_data_provider) noexcept
156 {
157 return fuzzed_data_provider.ConsumeBool() ?
158 fuzzed_data_provider.PickValueInArray({
159 CTxIn::SEQUENCE_FINAL,
160 CTxIn::MAX_SEQUENCE_NONFINAL,
161 MAX_BIP125_RBF_SEQUENCE,
162 }) :
163 fuzzed_data_provider.ConsumeIntegral<uint32_t>();
164 }
165
166 std::map<COutPoint, Coin> ConsumeCoins(FuzzedDataProvider& fuzzed_data_provider) noexcept
167 {
168 std::map<COutPoint, Coin> coins;
169 LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 10000) {
170 const std::optional<COutPoint> outpoint{ConsumeDeserializable<COutPoint>(fuzzed_data_provider)};
171 if (!outpoint) {
172 break;
173 }
174 const std::optional<Coin> coin{ConsumeDeserializable<Coin>(fuzzed_data_provider)};
175 if (!coin) {
176 break;
177 }
178 coins[*outpoint] = *coin;
179 }
180
181 return coins;
182 }
183
184 CTxDestination ConsumeTxDestination(FuzzedDataProvider& fuzzed_data_provider) noexcept
185 {
186 CTxDestination tx_destination;
187 const size_t call_size{CallOneOf(
188 fuzzed_data_provider,
189 [&] {
190 tx_destination = CNoDestination{};
191 },
192 [&] {
193 bool compressed = fuzzed_data_provider.ConsumeBool();
194 CPubKey pk{ConstructPubKeyBytes(
195 fuzzed_data_provider,
196 ConsumeFixedLengthByteVector(fuzzed_data_provider, (compressed ? CPubKey::COMPRESSED_SIZE : CPubKey::SIZE)),
197 compressed
198 )};
199 tx_destination = PubKeyDestination{pk};
200 },
201 [&] {
202 tx_destination = PKHash{ConsumeUInt160(fuzzed_data_provider)};
203 },
204 [&] {
205 tx_destination = ScriptHash{ConsumeUInt160(fuzzed_data_provider)};
206 },
207 [&] {
208 tx_destination = WitnessV0ScriptHash{ConsumeUInt256(fuzzed_data_provider)};
209 },
210 [&] {
211 tx_destination = WitnessV0KeyHash{ConsumeUInt160(fuzzed_data_provider)};
212 },
213 [&] {
214 tx_destination = WitnessV1Taproot{XOnlyPubKey{ConsumeUInt256(fuzzed_data_provider)}};
215 },
216 [&] {
217 tx_destination = PayToAnchor{};
218 },
219 [&] {
220 std::vector<unsigned char> program{ConsumeRandomLengthByteVector(fuzzed_data_provider, /*max_length=*/40)};
221 if (program.size() < 2) {
222 program = {0, 0};
223 }
224 tx_destination = WitnessUnknown{fuzzed_data_provider.ConsumeIntegralInRange<unsigned int>(2, 16), program};
225 })};
226 Assert(call_size == std::variant_size_v<CTxDestination>);
227 return tx_destination;
228 }
229
230 CKey ConsumePrivateKey(FuzzedDataProvider& fuzzed_data_provider, std::optional<bool> compressed) noexcept
231 {
232 auto key_data = fuzzed_data_provider.ConsumeBytes<uint8_t>(32);
233 key_data.resize(32);
234 CKey key;
235 bool compressed_value = compressed ? *compressed : fuzzed_data_provider.ConsumeBool();
236 key.Set(key_data.begin(), key_data.end(), compressed_value);
237 return key;
238 }
239
240 bool ContainsSpentInput(const CTransaction& tx, const CCoinsViewCache& inputs) noexcept
241 {
242 for (const CTxIn& tx_in : tx.vin) {
243 const Coin& coin = inputs.AccessCoin(tx_in.prevout);
244 if (coin.IsSpent()) {
245 return true;
246 }
247 }
248 return false;
249 }
250
251 FILE* FuzzedFileProvider::open()
252 {
253 SetFuzzedErrNo(m_fuzzed_data_provider);
254 if (m_fuzzed_data_provider.ConsumeBool()) {
255 return nullptr;
256 }
257 std::string mode;
258 CallOneOf(
259 m_fuzzed_data_provider,
260 [&] {
261 mode = "r";
262 },
263 [&] {
264 mode = "r+";
265 },
266 [&] {
267 mode = "w";
268 },
269 [&] {
270 mode = "w+";
271 },
272 [&] {
273 mode = "a";
274 },
275 [&] {
276 mode = "a+";
277 });
278 #if defined _GNU_SOURCE && (defined(__linux__) || defined(__FreeBSD__))
279 const cookie_io_functions_t io_hooks = {
280 FuzzedFileProvider::read,
281 FuzzedFileProvider::write,
282 FuzzedFileProvider::seek,
283 FuzzedFileProvider::close,
284 };
285 return fopencookie(this, mode.c_str(), io_hooks);
286 #else
287 (void)mode;
288 return nullptr;
289 #endif
290 }
291
292 ssize_t FuzzedFileProvider::read(void* cookie, char* buf, size_t size)
293 {
294 FuzzedFileProvider* fuzzed_file = (FuzzedFileProvider*)cookie;
295 SetFuzzedErrNo(fuzzed_file->m_fuzzed_data_provider);
296 if (buf == nullptr || size == 0 || fuzzed_file->m_fuzzed_data_provider.ConsumeBool()) {
297 return fuzzed_file->m_fuzzed_data_provider.ConsumeBool() ? 0 : -1;
298 }
299 const std::vector<uint8_t> random_bytes = fuzzed_file->m_fuzzed_data_provider.ConsumeBytes<uint8_t>(size);
300 if (random_bytes.empty()) {
301 return 0;
302 }
303 std::memcpy(buf, random_bytes.data(), random_bytes.size());
304 if (AdditionOverflow(fuzzed_file->m_offset, (int64_t)random_bytes.size())) {
305 return fuzzed_file->m_fuzzed_data_provider.ConsumeBool() ? 0 : -1;
306 }
307 fuzzed_file->m_offset += random_bytes.size();
308 return random_bytes.size();
309 }
310
311 ssize_t FuzzedFileProvider::write(void* cookie, const char* buf, size_t size)
312 {
313 FuzzedFileProvider* fuzzed_file = (FuzzedFileProvider*)cookie;
314 SetFuzzedErrNo(fuzzed_file->m_fuzzed_data_provider);
315 const ssize_t n = fuzzed_file->m_fuzzed_data_provider.ConsumeIntegralInRange<ssize_t>(0, size);
316 if (AdditionOverflow(fuzzed_file->m_offset, (int64_t)n)) {
317 return 0;
318 }
319 fuzzed_file->m_offset += n;
320 return n;
321 }
322
323 int FuzzedFileProvider::seek(void* cookie, int64_t* offset, int whence)
324 {
325 assert(whence == SEEK_SET || whence == SEEK_CUR || whence == SEEK_END);
326 FuzzedFileProvider* fuzzed_file = (FuzzedFileProvider*)cookie;
327 SetFuzzedErrNo(fuzzed_file->m_fuzzed_data_provider);
328 int64_t new_offset = 0;
329 if (whence == SEEK_SET) {
330 new_offset = *offset;
331 } else if (whence == SEEK_CUR) {
332 if (AdditionOverflow(fuzzed_file->m_offset, *offset)) {
333 return -1;
334 }
335 new_offset = fuzzed_file->m_offset + *offset;
336 } else if (whence == SEEK_END) {
337 const int64_t n = fuzzed_file->m_fuzzed_data_provider.ConsumeIntegralInRange<int64_t>(0, 4096);
338 if (AdditionOverflow(n, *offset)) {
339 return -1;
340 }
341 new_offset = n + *offset;
342 }
343 if (new_offset < 0) {
344 return -1;
345 }
346 fuzzed_file->m_offset = new_offset;
347 *offset = new_offset;
348 return fuzzed_file->m_fuzzed_data_provider.ConsumeIntegralInRange<int>(-1, 0);
349 }
350
351 int FuzzedFileProvider::close(void* cookie)
352 {
353 FuzzedFileProvider* fuzzed_file = (FuzzedFileProvider*)cookie;
354 SetFuzzedErrNo(fuzzed_file->m_fuzzed_data_provider);
355 return fuzzed_file->m_fuzzed_data_provider.ConsumeIntegralInRange<int>(-1, 0);
356 }
357