Where are inner null bytes valid in p2p messages

External question — Bitcoin Stack Exchange Author: yancy Original post: https://bitcoin.stackexchange.com/questions/130721 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. P2P messages use null bytes as padding when the field size is larger than the content. For example, a command field is interpreted as 12 byte ASCII, so the version command is typically as follows: version\0\0\0\0\0 My question is, is it also valid to have inner null bytes? eg: ver\0sion\0\0\0\0 Some protocol applications I notice treat inner null bytes as valid, which seems mistaken.

External answer — Bitcoin Stack Exchange Author: RedGrittyBrick Original post: https://bitcoin.stackexchange.com/a/130756 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. OP reported: bitcoin-core will reject messages that contain inner null characters in the command field of a network header.