Re: [TLS] Possible blocking of Encrypted SNI extension in China
Carrick Bartle <cbartle891@icloud.com> Thu, 13 August 2020 20:04 UTC
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From: Carrick Bartle <cbartle891@icloud.com>
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Date: Thu, 13 Aug 2020 13:04:48 -0700
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To: David Fifield <david@bamsoftware.com>
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Subject: Re: [TLS] Possible blocking of Encrypted SNI extension in China
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Weird. Thanks for the update. How are you confirming that it's blocked from inside-out? > On Aug 13, 2020, at 10:30 AM, David Fifield <david@bamsoftware.com> wrote: > > On Fri, Aug 07, 2020 at 05:56:30PM -0600, David Fifield wrote: >> Most of the functions of the Great Firewall work bidirectionally, and >> the ESNI detection and blocking are no exception. Sending an >> ESNI-containing ClientHello from *outside* of China to a server >> *inside* results in temporary blocking, just the same as sending one >> from the inside to the outside. This makes it easy to experiment with, >> even if you don't control a host in China. > > Triggering blocking from the outside no longer works. ESNI connections > that originate inside the firewall are still blocked. This was first > observed by GFW report, who were able to isolate the change from > bidirectionality to unidirectional to a five-minute window: between > 06:27 and 06:32 UTC on 2020-08-13. I tried it myself, and I confirm that > I am not now able to trigger ESNI blocking from outside the firewall. > https://github.com/net4people/bbs/issues/43#issuecomment-673322409 > > _______________________________________________ > TLS mailing list > TLS@ietf.org > https://www.ietf.org/mailman/listinfo/tls
- [TLS] Possible blocking of Encrypted SNI extensio… onoketa
- Re: [TLS] Possible blocking of Encrypted SNI exte… Christian Huitema
- Re: [TLS] Possible blocking of Encrypted SNI exte… David Fifield
- Re: [TLS] Possible blocking of Encrypted SNI exte… David Fifield
- Re: [TLS] Possible blocking of Encrypted SNI exte… Blumenthal, Uri - 0553 - MITLL
- Re: [TLS] Possible blocking of Encrypted SNI exte… Dmitry Belyavsky
- Re: [TLS] Possible blocking of Encrypted SNI exte… Peter Gutmann
- Re: [TLS] Possible blocking of Encrypted SNI exte… Christian Huitema
- Re: [TLS] Possible blocking of Encrypted SNI exte… Christopher Wood
- Re: [TLS] Possible blocking of Encrypted SNI exte… David Fifield
- Re: [TLS] Possible blocking of Encrypted SNI exte… Salz, Rich
- Re: [TLS] Possible blocking of Encrypted SNI exte… Peter Gutmann
- Re: [TLS] Possible blocking of Encrypted SNI exte… Christian Huitema
- Re: [TLS] Possible blocking of Encrypted SNI exte… Peter Gutmann
- Re: [TLS] Possible blocking of Encrypted SNI exte… Rob Sayre
- Re: [TLS] Possible blocking of Encrypted SNI exte… Peter Gutmann
- Re: [TLS] Possible blocking of Encrypted SNI exte… Rob Sayre
- Re: [TLS] Possible blocking of Encrypted SNI exte… Christian Huitema
- Re: [TLS] Possible blocking of Encrypted SNI exte… Rob Sayre
- Re: [TLS] Possible blocking of Encrypted SNI exte… Christian Huitema
- Re: [TLS] Possible blocking of Encrypted SNI exte… Peter Gutmann
- Re: [TLS] Possible blocking of Encrypted SNI exte… Rob Sayre
- Re: [TLS] Possible blocking of Encrypted SNI exte… David Fifield
- Re: [TLS] Possible blocking of Encrypted SNI exte… Nick Sullivan
- Re: [TLS] Possible blocking of Encrypted SNI exte… David Fifield
- Re: [TLS] Possible blocking of Encrypted SNI exte… Rob Sayre
- Re: [TLS] Possible blocking of Encrypted SNI exte… Peter Gutmann
- Re: [TLS] Possible blocking of Encrypted SNI exte… Rob Sayre
- Re: [TLS] Possible blocking of Encrypted SNI exte… Peter Gutmann
- Re: [TLS] Possible blocking of Encrypted SNI exte… Rob Sayre
- Re: [TLS] Possible blocking of Encrypted SNI exte… David Fifield
- Re: [TLS] Possible blocking of Encrypted SNI exte… David Fifield
- Re: [TLS] Possible blocking of Encrypted SNI exte… Carrick Bartle
- Re: [TLS] Possible blocking of Encrypted SNI exte… David Fifield