From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id C83841396D0 for ; Sun, 3 Sep 2017 18:08:17 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id B58721FC068; Sun, 3 Sep 2017 18:08:12 +0000 (UTC) Received: from smtp.gentoo.org (dev.gentoo.org [IPv6:2001:470:ea4a:1:5054:ff:fec7:86e4]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 683F11FC048 for ; Sun, 3 Sep 2017 18:08:12 +0000 (UTC) Received: from localhost (unknown [46.148.235.235]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: bircoph) by smtp.gentoo.org (Postfix) with ESMTPSA id 2B975341678 for ; Sun, 3 Sep 2017 18:08:09 +0000 (UTC) Date: Sun, 3 Sep 2017 21:08:06 +0300 From: Andrew Savchenko To: gentoo-dev@lists.gentoo.org Subject: Re: [gentoo-dev] [PATCH 2/2] git-r3.eclass: Explicitly warn about unsecure protocols Message-Id: <20170903210806.619fcd0868275a534a103cb7@gentoo.org> In-Reply-To: <20170825174601.6b000c42@pc1> References: <20170819082502.27716-1-mgorny@gentoo.org> <20170819082502.27716-2-mgorny@gentoo.org> <20170823114602.4b19ebe6b225f4a57af3448e@gentoo.org> <20170825174601.6b000c42@pc1> X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.30; i686-pc-linux-gnu) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@lists.gentoo.org Reply-to: gentoo-dev@lists.gentoo.org Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg="PGP-SHA512"; boundary="Signature=_Sun__3_Sep_2017_21_08_06_+0300_FIqLhOmGXrVQRCWy" X-Archives-Salt: c5c2e39b-afc9-4e4f-865e-4c6df193431e X-Archives-Hash: f50cbf1f59bf831f7bae94f8ffdd472e --Signature=_Sun__3_Sep_2017_21_08_06_+0300_FIqLhOmGXrVQRCWy Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, 25 Aug 2017 17:46:01 +0200 Hanno B=C3=B6ck wrote: > On Wed, 23 Aug 2017 11:46:02 +0300 > Andrew Savchenko wrote: >=20 > > Sigh... https also makes MITM attacks possible, especially if SSL > > or TLS < 1.2 is used or are allowed and protocol version downgrade > > attack may be performed. >=20 > None of that is true. >=20 > You're probably referring to attacks that were specific to certain > browser weaknesses, but they're irrelevant for this use case. =20 Some attack are indeed implementation specific, but there are several which are design flaws, e.g.: 1) BEAST attack[1]: TLS 1.0 is vulnerable regrardless of implementation (and all SSL versions). 2) BREACH attack[2]: basically this is a side-channel attack for compressed traffic. All TLS versions are still vulnerable, the only practical mitigation is to disable compression. It can be argued if this is a vulnerability in TLS or TLS protocol has nothing to do with side channels, but if a protocol is vulnerable to a side-channel implementation-agnostic attack, it is considered by many as a protocol misdesign. Really SSL/TLS are very good examples of how crypto solutions should not be designed and implemented. [1] https://www.gracefulsecurity.com/what-is-beast/ [2] http://breachattack.com/ Best regards, Andrew Savchenko --Signature=_Sun__3_Sep_2017_21_08_06_+0300_FIqLhOmGXrVQRCWy Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE63ZIHsdeM+1XgNer9lNaM7oe5I0FAlmsRQYACgkQ9lNaM7oe 5I0IRA//dGHfW6Fqgq8VVhD3r+LwoYh7vB4S7KBC3JZW4yu7jq/ne7oul2XLTO5Q 8TMv9/8opJiWbcu5AHPUS9KD5pHVKuWjCNaykSGmnni4Y2gcI+J+K1j4+IKjSoA6 4IZGnTbyGtTRL/CKtIThRnRXKvTEhbatjmjM6HRx1TzFIL7UKR+M/ZZOoZRjr5Ko XuBEERZMQFJfPHUKxn3f80BpH0xn/q2E6TArTq0hZNbLwnCs0tcs5eXilyPkyh8c 0OA1SbEhkCacXrfH+kvrdVr1bf/n9Us2HPZsNDCPHS4v3qRE+imvliUrfe0/dsLO AAmDjPgYAKFKQMAXsCOeqDtBJ1TZDMVM5INTAeBmMRpYwXoCH9PKR3//JYkTn7Xe wkLvV2YI3IGz8DVip7QEQ+oCEaLSjAbn6xrN9GA1HQqitjgkbcWXHKh+4i0QFGEo M/MfwKFpOzwM2Sg4C5HvzngvAg2NjEjk24q2hnIcAk+iUMpBXnvM1/hSTID4NjT5 fxcI9a/2hoMTiFXdJGnDW/9U524fl1452bMsDJQeZM8//0ZEfWfDaBW5GoAfmfvO +ndNNB7Cju+P0WbV3T0UdiXK7jCuBIRRqDOduo8hckvf75e5EHqe4Ve/TllKqe7Q 4wbGV8e3zQef7VcbqMz9az4aiYrEIcCKGnj89iOrmAEr8mfZXVs= =F+dS -----END PGP SIGNATURE----- --Signature=_Sun__3_Sep_2017_21_08_06_+0300_FIqLhOmGXrVQRCWy--