diff options
| -rw-r--r-- | src/core_read.cpp | 59 | ||||
| -rwxr-xr-x | test/functional/rpc_rawtransaction.py | 7 |
2 files changed, 57 insertions, 9 deletions
diff --git a/src/core_read.cpp b/src/core_read.cpp index a2eebbd528..7687a86185 100644 --- a/src/core_read.cpp +++ b/src/core_read.cpp @@ -126,31 +126,72 @@ static bool CheckTxScriptsSanity(const CMutableTransaction& tx) static bool DecodeTx(CMutableTransaction& tx, const std::vector<unsigned char>& tx_data, bool try_no_witness, bool try_witness) { + // General strategy: + // - Decode both with extended serialization (which interprets the 0x0001 tag as a marker for + // the presense of witnesses) and with legacy serialization (which interprets the tag as a + // 0-input 1-output incomplete transaction). + // - Restricted by try_no_witness (which disables legacy if false) and try_witness (which + // disables extended if false). + // - Ignore serializations that do not fully consume the hex string. + // - If neither succeeds, fail. + // - If only one succeeds, return that one. + // - If both decode attempts succeed: + // - If only one passes the CheckTxScriptsSanity check, return that one. + // - If neither or both pass CheckTxScriptsSanity, return the extended one. + + CMutableTransaction tx_extended, tx_legacy; + bool ok_extended = false, ok_legacy = false; + + // Try decoding with extended serialization support, and remember if the result successfully + // consumes the entire input. if (try_witness) { CDataStream ssData(tx_data, SER_NETWORK, PROTOCOL_VERSION); try { - ssData >> tx; - // If transaction looks sane, we don't try other mode even if requested - if (ssData.empty() && (!try_no_witness || CheckTxScriptsSanity(tx))) { - return true; - } + ssData >> tx_extended; + if (ssData.empty()) ok_extended = true; } catch (const std::exception&) { // Fall through. } } + // Optimization: if extended decoding succeeded and the result passes CheckTxScriptsSanity, + // don't bother decoding the other way. + if (ok_extended && CheckTxScriptsSanity(tx_extended)) { + tx = std::move(tx_extended); + return true; + } + + // Try decoding with legacy serialization, and remember if the result successfully consumes the entire input. if (try_no_witness) { CDataStream ssData(tx_data, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS); try { - ssData >> tx; - if (ssData.empty()) { - return true; - } + ssData >> tx_legacy; + if (ssData.empty()) ok_legacy = true; } catch (const std::exception&) { // Fall through. } } + // If legacy decoding succeeded and passes CheckTxScriptsSanity, that's our answer, as we know + // at this point that extended decoding either failed or doesn't pass the sanity check. + if (ok_legacy && CheckTxScriptsSanity(tx_legacy)) { + tx = std::move(tx_legacy); + return true; + } + + // If extended decoding succeeded, and neither decoding passes sanity, return the extended one. + if (ok_extended) { + tx = std::move(tx_extended); + return true; + } + + // If legacy decoding succeeded and extended didn't, return the legacy one. + if (ok_legacy) { + tx = std::move(tx_legacy); + return true; + } + + // If none succeeded, we failed. return false; } diff --git a/test/functional/rpc_rawtransaction.py b/test/functional/rpc_rawtransaction.py index 554c30c0d2..60e66a27c9 100755 --- a/test/functional/rpc_rawtransaction.py +++ b/test/functional/rpc_rawtransaction.py @@ -372,6 +372,13 @@ class RawTransactionsTest(BitcoinTestFramework): encrawtx = "01000000010000000000000072c1a6a246ae63f74f931e8365e15a089c68d61900000000000000000000ffffffff0100e1f505000000000000000000" decrawtx = self.nodes[0].decoderawtransaction(encrawtx, False) # decode as non-witness transaction assert_equal(decrawtx['vout'][0]['value'], Decimal('1.00000000')) + # known ambiguous transaction in the chain (see https://github.com/bitcoin/bitcoin/issues/20579) + encrawtx = "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" + decrawtx = self.nodes[0].decoderawtransaction(encrawtx) + decrawtx_wit = self.nodes[0].decoderawtransaction(encrawtx, True) + assert_raises_rpc_error(-22, 'TX decode failed', self.nodes[0].decoderawtransaction, encrawtx, False) # fails to decode as non-witness transaction + assert_equal(decrawtx, decrawtx_wit) # the witness interpretation should be chosen + assert_equal(decrawtx['vin'][0]['coinbase'], "03c68708046ff8415c622f4254432e434f4d2ffabe6d6de1965d02c68f928e5b244ab1965115a36f56eb997633c7f690124bbf43644e23080000000ca3d3af6d005a65ff0200fd00000000") # Basic signrawtransaction test addr = self.nodes[1].getnewaddress() |