editorial: key update requirement is hard to understand

[marten-seemann]

Section 19 of [QUIC-TRANSPORT] encodes the Connection ID Sequence Number as a variable-length integer, allowing values up to 2^62-1; in this specification, a range of less than 2^32-1 values MUST be used before updating the packet protection key.

I think I know what this is supposed to say, but I’m having trouble parsing this sentence. It would probably benefit from being reworded as a „MUST NOT use more than 2ˆ32-1 connection IDs without a key update“, or similar.

[kazuho]

Yeah I think the entire section failed to reflect that we allow CID sequence numbers above 2^32. It goes like

To calculate the nonce, a 96 bit path-and-packet-number is composed of the 32 bit Connection ID Sequence Number in byte order,

but what is exactly 32-bit CID sequence number?