Subject: [TLS] Barry Leiba's No Objection on draft-ietf-tls-sni-encryption-05: (with COMMENT)

From: Barry Leiba via Datatracker <[email-masked]>
Date: Wed, 04 Sep 2019 20:41:07 -0700

Barry Leiba has entered the following ballot position for
draft-ietf-tls-sni-encryption-05: No Objection

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COMMENT:
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Lovely document; thanks.  Just a collection of nits here:

— Section 1 —

   These attempts have generally floundered,

I think the word you want here is “foundered”, without the “l”.

— Section 2.1 —

      which inspection would intrude with the privacy of employees.

“Intrude on”.

— Section 2.2 —

   and protection of server certificates transmissions

“certificate”

— Section 2.3 —

   Deploying SNI encryption will help thwarting most of the

Will “help thwart” or “help in thwarting”; I think the former sounds better.

   can however be realized by other means.

Needs commas around “, however,” .

— Section 3.1 —

   these designs can be broken by a simple replay attack, which works as
   follow:

“as follows”

   attacks breaks that goal

“break”

— Section 3.2 —

   the multiplexed server, and by every users of the protected services.

By “every user” or “all users”.

— Section 3.4 —

   of TLS handshakes use SNI encryption.  If that was the case, the

“If that were the case,” subjunctive mood.

— Section 3.5 —

   If the corresponding private key was compromised,

“is compromised,” or, better, “should be compromised,” subjunctive again.

— Section 3.6 —

   We can design solutions in which a fronting service act as a relay

“acts”

   Middle attack by the fronting service.  The downside is the the

“that the”

   client will not verify the identity of the fronting service with
   risks discussed in , but solutions will have to mitigate this risks.

You’re missing something here, a reference after “in”?  And “those risks.”

   regular fronting server, using for example spoofed DNS responses

Needs commas around “, for example,” .

— Section 3.7 —

   Multiple other applications currently use TLS, including for example
   SMTP [RFC5246], DNS [RFC7858], or XMPP [RFC7590].

Needs commas around “, for example,” .
Also, “and”, rather than “or”.

   These applications too will benefit of SNI encryption.

Needs commas around “, too,” .  Or make it, “These applications will also benefit...”

   HTTP only methods like those

“HTTP-only” needs a hyphen.

   to the need of an application-agnostic solution, that would be
   implemented fully in the TLS layer.

“need for”, and “which would”.

— Section 3.7.1 —

   specific port numbers exposed in some network.

Should this be “networks”?

   Applications would not need to do that if the ALPN was hidden

“were hidden”

— Section 3.7.2 —

   Support other transports than TCP

“Support Transports Other than TCP”

   requirement to encrypt the SNI apply just as well

“applies”

— Section 4 —

   when the fronting server and the hidden server are "co-tenant" of the

“co-tenants”

   There are however a few issues regarding discovery

Needs commas around “, however,” .

   o  The client browser's has to be directed to access

The “client’s browser”.

      cryptographic proof that the content does in fact come from

Needs commas around “, in fact,” .

      The solution does thus not mitigate

Needs commas around “, thus,” .

   support HTTP Fronting

“supports”

   applications over HTTP, such as for example DNS over HTTPS

Needs commas around “, for example,” .

— Section 4.1 —

   It also requires that the fronting server decrypts and relay
   messages to the hidden server.

“decrypt”, more subjunctive.

— Section 4.2 —

   be performed by distributing fake advice, such as "to reach example
   hidden.example.com, use fake.example.com as a fronting server",

There’s an extra “example” on the first line.

   We can observe that content distribution network have a similar

“networks”

— Section 5 —

   The current HTTP based

“HTTP-based” needs a hyphen.

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From: Christian Huitema <[email-masked]>
Date: Wed, 4 Sep 2019 22:04:15 -0700

Thanks, Barry. I will incorporate your fixes in the next version, due soon.

-- Christian Huitema

On 9/4/2019 8:41 PM, Barry Leiba via Datatracker wrote:
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