rpc: Disallow non-matching transactions in combinerawtransaction #31091

1. 
   instagibbs commented at 10:06 am on October 15, 2024: member

   Resolves #25980 by disallowing obviously broken usage. If txid doesn’t match, we can’t sensibly combine it.
2. 
   DrahtBot commented at 10:06 am on October 15, 2024: contributor

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3. DrahtBot added the label RPC/REST/ZMQ on Oct 15, 2024
4. rpc: Disallow non-matching transactions in combinerawtransaction 601478629d
5. instagibbs force-pushed on Oct 15, 2024
6. in src/rpc/rawtransaction.cpp:661 in 601478629d

   656     for (unsigned int idx = 0; idx < txs.size(); idx++) {
   657         if (!DecodeHexTx(txVariants[idx], txs[idx].get_str())) {
   658             throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed for tx %d. Make sure the tx has at least one input.", idx));
   659         }
   660+        if (txid.has_value() && txid.value() != txVariants[idx].GetHash()) {
   661+            throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Transactions to be combine do not match."));
   

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   maflcko commented at 10:43 am on October 15, 2024:

   0            throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Transactions to be combined do not match."));
   

   nit?

7. 
   instagibbs commented at 10:44 am on October 15, 2024: member

   nevermind, pre-segwit is lame, im outta here
8. instagibbs closed this on Oct 15, 2024

   ---

9. in src/rpc/rawtransaction.cpp:660 in 601478629d

   651@@ -652,10 +652,16 @@ static RPCHelpMan combinerawtransaction()
   652     UniValue txs = request.params[0].get_array();
   653     std::vector<CMutableTransaction> txVariants(txs.size());
   654 
   655+    std::optional<Txid> txid;
   656     for (unsigned int idx = 0; idx < txs.size(); idx++) {
   657         if (!DecodeHexTx(txVariants[idx], txs[idx].get_str())) {
   658             throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed for tx %d. Make sure the tx has at least one input.", idx));
   659         }
   660+        if (txid.has_value() && txid.value() != txVariants[idx].GetHash()) {
   

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   achow101 commented at 10:48 am on October 15, 2024:

   For txs with pre-segwit and nested segwit inputs, txids will not match because the scriptSigs will be different. This check is actually more involved as the transactions need to have scriptSigs stripped.
10. bitcoin locked this on Oct 15, 2025

Contributors
instagibbs DrahtBot maflcko achow101

Labels
RPC/REST/ZMQ