sighash_tests.cpp raw
1 // Copyright (c) 2013-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 <common/system.h>
6 #include <consensus/tx_check.h>
7 #include <consensus/validation.h>
8 #include <hash.h>
9 #include <script/interpreter.h>
10 #include <script/script.h>
11 #include <serialize.h>
12 #include <streams.h>
13 #include <test/data/sighash.json.h>
14 #include <test/util/common.h>
15 #include <test/util/json.h>
16 #include <test/util/random.h>
17 #include <test/util/setup_common.h>
18 #include <util/strencodings.h>
19
20 #include <iostream>
21
22 #include <boost/test/unit_test.hpp>
23
24 #include <univalue.h>
25
26 // Old script.cpp SignatureHash function
27 uint256 static SignatureHashOld(CScript scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType)
28 {
29 if (nIn >= txTo.vin.size())
30 {
31 return uint256::ONE;
32 }
33 CMutableTransaction txTmp(txTo);
34
35 // In case concatenating two scripts ends up with two codeseparators,
36 // or an extra one at the end, this prevents all those possible incompatibilities.
37 FindAndDelete(scriptCode, CScript(OP_CODESEPARATOR));
38
39 // Blank out other inputs' signatures
40 for (unsigned int i = 0; i < txTmp.vin.size(); i++)
41 txTmp.vin[i].scriptSig = CScript();
42 txTmp.vin[nIn].scriptSig = scriptCode;
43
44 // Blank out some of the outputs
45 if ((nHashType & 0x1f) == SIGHASH_NONE)
46 {
47 // Wildcard payee
48 txTmp.vout.clear();
49
50 // Let the others update at will
51 for (unsigned int i = 0; i < txTmp.vin.size(); i++)
52 if (i != nIn)
53 txTmp.vin[i].nSequence = 0;
54 }
55 else if ((nHashType & 0x1f) == SIGHASH_SINGLE)
56 {
57 // Only lock-in the txout payee at same index as txin
58 unsigned int nOut = nIn;
59 if (nOut >= txTmp.vout.size())
60 {
61 return uint256::ONE;
62 }
63 txTmp.vout.resize(nOut+1);
64 for (unsigned int i = 0; i < nOut; i++)
65 txTmp.vout[i].SetNull();
66
67 // Let the others update at will
68 for (unsigned int i = 0; i < txTmp.vin.size(); i++)
69 if (i != nIn)
70 txTmp.vin[i].nSequence = 0;
71 }
72
73 // Blank out other inputs completely, not recommended for open transactions
74 if (nHashType & SIGHASH_ANYONECANPAY)
75 {
76 txTmp.vin[0] = txTmp.vin[nIn];
77 txTmp.vin.resize(1);
78 }
79
80 // Serialize and hash
81 HashWriter ss{};
82 ss << TX_NO_WITNESS(txTmp) << nHashType;
83 return ss.GetHash();
84 }
85
86 struct SigHashTest : BasicTestingSetup {
87 void RandomScript(CScript &script) {
88 static const opcodetype oplist[] = {OP_FALSE, OP_1, OP_2, OP_3, OP_CHECKSIG, OP_IF, OP_VERIF, OP_RETURN, OP_CODESEPARATOR};
89 script = CScript();
90 int ops = (m_rng.randrange(10));
91 for (int i=0; i<ops; i++)
92 script << oplist[m_rng.randrange(std::size(oplist))];
93 }
94
95 void RandomTransaction(CMutableTransaction& tx, bool fSingle)
96 {
97 tx.version = m_rng.rand32();
98 tx.vin.clear();
99 tx.vout.clear();
100 tx.nLockTime = (m_rng.randbool()) ? m_rng.rand32() : 0;
101 int ins = (m_rng.randbits(2)) + 1;
102 int outs = fSingle ? ins : (m_rng.randbits(2)) + 1;
103 for (int in = 0; in < ins; in++) {
104 tx.vin.emplace_back();
105 CTxIn &txin = tx.vin.back();
106 txin.prevout.hash = Txid::FromUint256(m_rng.rand256());
107 txin.prevout.n = m_rng.randbits(2);
108 RandomScript(txin.scriptSig);
109 txin.nSequence = (m_rng.randbool()) ? m_rng.rand32() : std::numeric_limits<uint32_t>::max();
110 }
111 for (int out = 0; out < outs; out++) {
112 tx.vout.emplace_back();
113 CTxOut &txout = tx.vout.back();
114 txout.nValue = RandMoney(m_rng);
115 RandomScript(txout.scriptPubKey);
116 }
117 }
118 }; // struct SigHashTest
119
120 BOOST_FIXTURE_TEST_SUITE(sighash_tests, SigHashTest)
121
122 BOOST_AUTO_TEST_CASE(sighash_test)
123 {
124 #if defined(PRINT_SIGHASH_JSON)
125 std::cout << "[\n";
126 std::cout << "\t[\"raw_transaction, script, input_index, hashType, signature_hash (result)\"],\n";
127 int nRandomTests = 500;
128 #else
129 int nRandomTests = 50000;
130 #endif
131 for (int i=0; i<nRandomTests; i++) {
132 int nHashType{int(m_rng.rand32())};
133 CMutableTransaction txTo;
134 RandomTransaction(txTo, (nHashType & 0x1f) == SIGHASH_SINGLE);
135 CScript scriptCode;
136 RandomScript(scriptCode);
137 int nIn = m_rng.randrange(txTo.vin.size());
138
139 uint256 sh, sho;
140 sho = SignatureHashOld(scriptCode, CTransaction(txTo), nIn, nHashType);
141 sh = SignatureHash(scriptCode, txTo, nIn, nHashType, 0, SigVersion::BASE);
142 #if defined(PRINT_SIGHASH_JSON)
143 DataStream ss;
144 ss << TX_WITH_WITNESS(txTo);
145
146 std::cout << "\t[\"" ;
147 std::cout << HexStr(ss) << "\", \"";
148 std::cout << HexStr(scriptCode) << "\", ";
149 std::cout << nIn << ", ";
150 std::cout << nHashType << ", \"";
151 std::cout << sho.GetHex() << "\"]";
152 if (i+1 != nRandomTests) {
153 std::cout << ",";
154 }
155 std::cout << "\n";
156 #endif
157 BOOST_CHECK(sh == sho);
158 }
159 #if defined(PRINT_SIGHASH_JSON)
160 std::cout << "]\n";
161 #endif
162 }
163
164 // Goal: check that SignatureHash generates correct hash
165 BOOST_AUTO_TEST_CASE(sighash_from_data)
166 {
167 UniValue tests = read_json(json_tests::sighash);
168
169 for (unsigned int idx = 0; idx < tests.size(); idx++) {
170 const UniValue& test = tests[idx];
171 std::string strTest = test.write();
172 if (test.size() < 1) // Allow for extra stuff (useful for comments)
173 {
174 BOOST_ERROR("Bad test: " << strTest);
175 continue;
176 }
177 if (test.size() == 1) continue; // comment
178
179 std::string raw_tx, raw_script, sigHashHex;
180 int nIn, nHashType;
181 uint256 sh;
182 CTransactionRef tx;
183 CScript scriptCode = CScript();
184
185 try {
186 // deserialize test data
187 raw_tx = test[0].get_str();
188 raw_script = test[1].get_str();
189 nIn = test[2].getInt<int>();
190 nHashType = test[3].getInt<int>();
191 sigHashHex = test[4].get_str();
192
193 SpanReader{ParseHex(raw_tx)} >> TX_WITH_WITNESS(tx);
194
195 TxValidationState state;
196 BOOST_CHECK_MESSAGE(CheckTransaction(*tx, state), strTest);
197 BOOST_CHECK(state.IsValid());
198
199 std::vector<unsigned char> raw = ParseHex(raw_script);
200 scriptCode.insert(scriptCode.end(), raw.begin(), raw.end());
201 } catch (...) {
202 BOOST_ERROR("Bad test, couldn't deserialize data: " << strTest);
203 continue;
204 }
205
206 sh = SignatureHash(scriptCode, *tx, nIn, nHashType, 0, SigVersion::BASE);
207 BOOST_CHECK_MESSAGE(sh.GetHex() == sigHashHex, strTest);
208 }
209 }
210
211 BOOST_AUTO_TEST_CASE(sighash_caching)
212 {
213 // Get a script, transaction and parameters as inputs to the sighash function.
214 CScript scriptcode;
215 RandomScript(scriptcode);
216 CScript diff_scriptcode{scriptcode};
217 diff_scriptcode << OP_1;
218 CMutableTransaction tx;
219 RandomTransaction(tx, /*fSingle=*/false);
220 const auto in_index{static_cast<uint32_t>(m_rng.randrange(tx.vin.size()))};
221 const auto amount{m_rng.rand<CAmount>()};
222
223 // Exercise the sighash function under both legacy and segwit v0.
224 for (const auto sigversion: {SigVersion::BASE, SigVersion::WITNESS_V0}) {
225 // For each, run it against all the 6 standard hash types and a few additional random ones.
226 std::vector<int32_t> hash_types{{SIGHASH_ALL, SIGHASH_SINGLE, SIGHASH_NONE, SIGHASH_ALL | SIGHASH_ANYONECANPAY,
227 SIGHASH_SINGLE | SIGHASH_ANYONECANPAY, SIGHASH_NONE | SIGHASH_ANYONECANPAY,
228 SIGHASH_ANYONECANPAY, 0, std::numeric_limits<int32_t>::max()}};
229 for (int i{0}; i < 10; ++i) {
230 hash_types.push_back(i % 2 == 0 ? m_rng.rand<int8_t>() : m_rng.rand<int32_t>());
231 }
232
233 // Reuse the same cache across script types. This must not cause any issue as the cached value for one hash type must never
234 // be confused for another (instantiating the cache within the loop instead would prevent testing this).
235 SigHashCache cache;
236 for (const auto hash_type: hash_types) {
237 const bool expect_one{sigversion == SigVersion::BASE && ((hash_type & 0x1f) == SIGHASH_SINGLE) && in_index >= tx.vout.size()};
238
239 // The result of computing the sighash should be the same with or without cache.
240 const auto sighash_with_cache{SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &cache)};
241 const auto sighash_no_cache{SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, nullptr)};
242 BOOST_CHECK_EQUAL(sighash_with_cache, sighash_no_cache);
243
244 // Calling the cached version again should return the same value again.
245 BOOST_CHECK_EQUAL(sighash_with_cache, SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &cache));
246
247 // While here we might as well also check that the result for legacy is the same as for the old SignatureHash() function.
248 if (sigversion == SigVersion::BASE) {
249 BOOST_CHECK_EQUAL(sighash_with_cache, SignatureHashOld(scriptcode, CTransaction(tx), in_index, hash_type));
250 }
251
252 // Calling with a different scriptcode (for instance in case a CODESEP is encountered) will not return the cache value but
253 // overwrite it. The sighash will always be different except in case of legacy SIGHASH_SINGLE bug.
254 const auto sighash_with_cache2{SignatureHash(diff_scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &cache)};
255 const auto sighash_no_cache2{SignatureHash(diff_scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, nullptr)};
256 BOOST_CHECK_EQUAL(sighash_with_cache2, sighash_no_cache2);
257 if (!expect_one) {
258 BOOST_CHECK_NE(sighash_with_cache, sighash_with_cache2);
259 } else {
260 BOOST_CHECK_EQUAL(sighash_with_cache, sighash_with_cache2);
261 BOOST_CHECK_EQUAL(sighash_with_cache, uint256::ONE);
262 }
263
264 // Calling the cached version again should return the same value again.
265 BOOST_CHECK_EQUAL(sighash_with_cache2, SignatureHash(diff_scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &cache));
266
267 // And if we store a different value for this scriptcode and hash type it will return that instead.
268 {
269 HashWriter h{};
270 h << 42;
271 cache.Store(hash_type, scriptcode, h);
272 const auto stored_hash{h.GetHash()};
273 BOOST_CHECK(cache.Load(hash_type, scriptcode, h));
274 const auto loaded_hash{h.GetHash()};
275 BOOST_CHECK_EQUAL(stored_hash, loaded_hash);
276 }
277
278 // And using this mutated cache with the sighash function will return the new value (except in the legacy SIGHASH_SINGLE bug
279 // case in which it'll return 1).
280 if (!expect_one) {
281 BOOST_CHECK_NE(SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &cache), sighash_with_cache);
282 HashWriter h{};
283 BOOST_CHECK(cache.Load(hash_type, scriptcode, h));
284 h << hash_type;
285 const auto new_hash{h.GetHash()};
286 BOOST_CHECK_EQUAL(SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &cache), new_hash);
287 } else {
288 BOOST_CHECK_EQUAL(SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &cache), uint256::ONE);
289 }
290
291 // Wipe the cache and restore the correct cached value for this scriptcode and hash_type before starting the next iteration.
292 HashWriter dummy{};
293 cache.Store(hash_type, diff_scriptcode, dummy);
294 (void)SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &cache);
295 BOOST_CHECK(cache.Load(hash_type, scriptcode, dummy) || expect_one);
296 }
297 }
298 }
299
300 BOOST_AUTO_TEST_SUITE_END()
301