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hub / github.com/ElementsProject/elements / IsStandardTx

Function IsStandardTx

src/policy/policy.cpp:98–162  ·  view source on GitHub ↗

Source from the content-addressed store, hash-verified

96}
97
98bool IsStandardTx(const CTransaction& tx, bool permit_bare_multisig, const CFeeRate& dust_relay_fee, std::string& reason)
99{
100 if (tx.nVersion > TX_MAX_STANDARD_VERSION || tx.nVersion < 1) {
101 reason = "version";
102 return false;
103 }
104
105 // Extremely large transactions with lots of inputs can cost the network
106 // almost as much to process as they cost the sender in fees, because
107 // computing signature hashes is O(ninputs*txsize). Limiting transactions
108 // to MAX_STANDARD_TX_WEIGHT mitigates CPU exhaustion attacks.
109 unsigned int sz = GetTransactionWeight(tx);
110 if (sz > MAX_STANDARD_TX_WEIGHT) {
111 reason = "tx-size";
112 return false;
113 }
114
115 for (const CTxIn& txin : tx.vin)
116 {
117 // Biggest 'standard' txin involving only keys is a 15-of-15 P2SH
118 // multisig with compressed keys (remember the 520 byte limit on
119 // redeemScript size). That works out to a (15*(33+1))+3=513 byte
120 // redeemScript, 513+1+15*(73+1)+3=1627 bytes of scriptSig, which
121 // we round off to 1650(MAX_STANDARD_SCRIPTSIG_SIZE) bytes for
122 // some minor future-proofing. That's also enough to spend a
123 // 20-of-20 CHECKMULTISIG scriptPubKey, though such a scriptPubKey
124 // is not considered standard.
125 if (txin.scriptSig.size() > MAX_STANDARD_SCRIPTSIG_SIZE) {
126 reason = "scriptsig-size";
127 return false;
128 }
129 if (!txin.scriptSig.IsPushOnly()) {
130 reason = "scriptsig-not-pushonly";
131 return false;
132 }
133 }
134
135 CChainParams params = Params();
136 unsigned int nDataOut = 0;
137 TxoutType whichType;
138 for (const CTxOut& txout : tx.vout) {
139 if (!::IsStandard(txout.scriptPubKey, whichType)) {
140 reason = "scriptpubkey";
141 return false;
142 }
143
144 if (whichType == TxoutType::NULL_DATA) {
145 nDataOut++;
146 } else if ((whichType == TxoutType::MULTISIG) && (!permit_bare_multisig)) {
147 reason = "bare-multisig";
148 return false;
149 } else if ((txout.nAsset.IsExplicit() && txout.nAsset.GetAsset() == policyAsset) && IsDust(txout, dust_relay_fee)) {
150 reason = "dust";
151 return false;
152 }
153 }
154
155 // only one OP_RETURN txout is permitted

Callers

nothing calls this directly

Calls 9

GetTransactionWeightFunction · 0.85
IsStandardFunction · 0.85
IsDustFunction · 0.85
IsPushOnlyMethod · 0.80
IsExplicitMethod · 0.80
GetAssetMethod · 0.80
GetMultiDataPermittedMethod · 0.80
ParamsClass · 0.50
sizeMethod · 0.45

Tested by

no test coverage detected