1499737 - Expose information whether resumption token provided via SSL_SetResumptionToken was used

Status: RESOLVED WONTFIX

(NSS :: Libraries, enhancement, P2)

Description

[Michal Novotny [:michal]]

This information will be mostly used for telemetry to decide whether external token cache have any real positive effect. It can be also used to find optimal expiration time of the tokens, so we can keep the database as small as possible.

Comment 1

[Franziskus Kiefer [:franziskus]]

Attachment: Bug 1499737 - callback for external token usage

So I'm not sure if this is really the right approach here.
Necko wants to be able to get data on whether a token was used or not on startup. Simple statistics on cache hits isn't enough because they have to know whether that first token was used. This is a pretty dumb implementation allowing that by registering a callback that tells an application when a token was used successfully and a function that compares two tokens.

I'm open to other ideas...

Comment 2

[Martin Thomson [:mt:]]

Is it possible that the necko code can just check for the intersection of an external token being set and session resumption (using SSL_GetChannelInfo and SSLChannelInfo.resumed)?

Comment 3

[Franziskus Kiefer [:franziskus]]

(In reply to Martin Thomson [:mt:] from comment #2)
> Is it possible that the necko code can just check for the intersection of an
> external token being set and session resumption (using SSL_GetChannelInfo
> and SSLChannelInfo.resumed)?

That's what I thought at first as well. But after talking to Michal this didn't seem enough. Michal can you explain again?

Comment 4

[Michal Novotny [:michal]]

(In reply to Franziskus Kiefer [:franziskus] from comment #3)
> (In reply to Martin Thomson [:mt:] from comment #2)
> > Is it possible that the necko code can just check for the intersection of an
> > external token being set and session resumption (using SSL_GetChannelInfo
> > and SSLChannelInfo.resumed)?
> 
> That's what I thought at first as well. But after talking to Michal this
> didn't seem enough. Michal can you explain again?

IIRC, you were referring to SSL_GetStatistics which gives global stats and it's not possible to find out whether the token was used for a particular connection. If I can use SSLChannelInfo.resumed in nsSocketTransport::OnSocketConnected, then it's exactly what I was looking for.

Comment 5

[Franziskus Kiefer [:franziskus]]

Ok I close this one then. Michal, please re-open if you find that the info you get from the SSLChannelInfo or statistics is not enough.