diff options
Diffstat (limited to 'src/policy/policy.cpp')
| -rw-r--r-- | src/policy/policy.cpp | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp index 0e9820da1e..69f2b456f1 100644 --- a/src/policy/policy.cpp +++ b/src/policy/policy.cpp @@ -9,7 +9,7 @@ #include <consensus/validation.h> #include <coins.h> - +#include <span.h> CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFeeIn) { @@ -206,6 +206,7 @@ bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs) // get the scriptPubKey corresponding to this input: CScript prevScript = prev.scriptPubKey; + bool p2sh = false; if (prevScript.IsPayToScriptHash()) { std::vector <std::vector<unsigned char> > stack; // If the scriptPubKey is P2SH, we try to extract the redeemScript casually by converting the scriptSig @@ -216,6 +217,7 @@ bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs) if (stack.empty()) return false; prevScript = CScript(stack.back().begin(), stack.back().end()); + p2sh = true; } int witnessversion = 0; @@ -237,6 +239,36 @@ bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs) return false; } } + + // Check policy limits for Taproot spends: + // - MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE limit for stack item size + // - No annexes + if (witnessversion == 1 && witnessprogram.size() == WITNESS_V1_TAPROOT_SIZE && !p2sh) { + // Taproot spend (non-P2SH-wrapped, version 1, witness program size 32; see BIP 341) + auto stack = MakeSpan(tx.vin[i].scriptWitness.stack); + if (stack.size() >= 2 && !stack.back().empty() && stack.back()[0] == ANNEX_TAG) { + // Annexes are nonstandard as long as no semantics are defined for them. + return false; + } + if (stack.size() >= 2) { + // Script path spend (2 or more stack elements after removing optional annex) + const auto& control_block = SpanPopBack(stack); + SpanPopBack(stack); // Ignore script + if (control_block.empty()) return false; // Empty control block is invalid + if ((control_block[0] & TAPROOT_LEAF_MASK) == TAPROOT_LEAF_TAPSCRIPT) { + // Leaf version 0xc0 (aka Tapscript, see BIP 342) + for (const auto& item : stack) { + if (item.size() > MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE) return false; + } + } + } else if (stack.size() == 1) { + // Key path spend (1 stack element after removing optional annex) + // (no policy rules apply) + } else { + // 0 stack elements; this is already invalid by consensus rules + return false; + } + } } return true; } |