Re: [quicwg/base-drafts] Mandate the use of short header for stateless reset (#2600)

Martin Thomson <notifications@github.com> Wed, 10 April 2019 02:25 UTC

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Subject: Re: [quicwg/base-drafts] Mandate the use of short header for stateless reset (#2600)
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martinthomson commented on this pull request.

Given that these are comments I would have expected to see on the *other* PR...

>  An endpoint MAY send a stateless reset in response to a packet with a long
-header.  This would not be effective if the stateless reset token was not yet
-available to a peer.  In this QUIC version, packets with a long header are only
-used during connection establishment.   Because the stateless reset token is not
-available until connection establishment is complete or near completion,
-ignoring an unknown packet with a long header might be more effective.
+header.  Sending a stateless reset is not effective prior to the stateless reset
+token being available to a peer.  In this QUIC version, packets with a long
+header are only used during connection establishment.   Because the stateless
+reset token is not available until connection establishment is complete or near
+completion, ignoring an unknown packet with a long header might be more
+effective than sending a stateless reset.

Long header packets are sent during connection establishment.  If you are sending them, you are still actively connecting.  Ignoring them will mean the other side times out, whereas a stateless reset is unlikely to be usable.

"as effective" would work I guess.

>  An endpoint MAY send a stateless reset in response to a packet with a long
-header.  This would not be effective if the stateless reset token was not yet
-available to a peer.  In this QUIC version, packets with a long header are only
-used during connection establishment.   Because the stateless reset token is not
-available until connection establishment is complete or near completion,
-ignoring an unknown packet with a long header might be more effective.
+header.  Sending a stateless reset is not effective prior to the stateless reset
+token being available to a peer.  In this QUIC version, packets with a long
+header are only used during connection establishment.   Because the stateless
+reset token is not available until connection establishment is complete or near

Either, depending on packet loss.

> @@ -2391,13 +2391,17 @@ the packet other than the last 16 bytes for carrying data.
 
 ### Detecting a Stateless Reset
 
-An endpoint detects a potential stateless reset when a incoming packet
-with a short header either cannot be associated with a connection,
-cannot be decrypted, or is marked as a duplicate packet.  The endpoint
-then compares the last 16 bytes of the packet with the Stateless Reset
-Token provided by its peer, either in a NEW_CONNECTION_ID frame or
-the server's transport parameters.  If these values are identical,
-the endpoint MUST enter the draining period and not send any further
+An endpoint detects a potential stateless reset when an incoming packet either
+cannot be associated with a connection, cannot be decrypted, or is marked as a
+duplicate packet.  The endpoint MUST then compare the last 16 bytes of the

Open an issue if you care.  I don't think that it's worth having wishy-washy SHOULDs here.

> @@ -2391,13 +2391,17 @@ the packet other than the last 16 bytes for carrying data.
 
 ### Detecting a Stateless Reset
 
-An endpoint detects a potential stateless reset when a incoming packet
-with a short header either cannot be associated with a connection,
-cannot be decrypted, or is marked as a duplicate packet.  The endpoint
-then compares the last 16 bytes of the packet with the Stateless Reset
-Token provided by its peer, either in a NEW_CONNECTION_ID frame or
-the server's transport parameters.  If these values are identical,
-the endpoint MUST enter the draining period and not send any further
+An endpoint detects a potential stateless reset when an incoming packet either
+cannot be associated with a connection, cannot be decrypted, or is marked as a
+duplicate packet.  The endpoint MUST then compare the last 16 bytes of the
+packet with all Stateless Reset Tokens that are associated with connection IDs
+that are currently in use.  This includes Stateless Reset Tokens from

That's not meaningful in terms of security, but that was implied.  I'll amend the other PR.

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