Author: Antoine Riard 2021-02-10 13:13:34
Published on: 2021-02-10T13:13:34+00:00
Antoine proposes to stop the processing of unrequested transactions in Bitcoin Core 22.0+ at TX message reception. This change is motivated by reducing the CPU DoS surface of Bitcoin Core around mempool acceptance. An unrequested transaction is one that is defined by which a "getdata" message for its specific identifier (either txid or wtxid) has not been previously issued by the node. Currently, an attacker can open multiple inbound connections to a node and send expensive to validate, junk transactions. Once the canonical INV/GETDATA sequence is enforced on the network, a further protection would be to deprioritize bandwidth and validation resources allocation, or even to wither connections with such DoSy peers. A permissioned peer (PF_RELAY) will still be able to bypass such restrictions. Raw TX message processing has always been tolerated by Core; thus, some Bitcoin clients aren't bothering with an INV/GETDATA sequence. Such a change will break their tx-relay capabilities on the p2p network and require adaptation from them. Given deployment time of any release, Antoine hopes it provides a window time wide enough before the old tx-processing behavior becomes the minority. Antoine is eager to gather feedback on this proposal, especially if such a change is deemed too much constraining or fast on any Bitcoin software.
Updated on: 2023-06-14T17:50:00.459052+00:00