From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 2B11EDCC for ; Tue, 16 Jan 2018 04:17:22 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from zinan.dashjr.org (zinan.dashjr.org [192.3.11.21]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id A120614E for ; Tue, 16 Jan 2018 04:17:21 +0000 (UTC) Received: from ishibashi.localnet (unknown [IPv6:2001:470:5:265::71]) (Authenticated sender: luke-jr) by zinan.dashjr.org (Postfix) with ESMTPSA id CEB4238A1F3D; Tue, 16 Jan 2018 04:15:56 +0000 (UTC) X-Hashcash: 1:25:180116:bitcoin-dev@lists.linuxfoundation.org::SI9izB6EVo+wAFEc:a59eG X-Hashcash: 1:25:180116:rusty@rustcorp.com.au::/E/fnXCyLdxWEIV7:cB1Ib X-Hashcash: 1:25:180116:roconnor@blockstream.io::GZhxer0R8fcqjtcv:Y=rh X-Hashcash: 1:25:180116:pieter.wuille@gmail.com::sIIYwiZnvhPuGZXS:Bfqo X-Hashcash: 1:25:180116:roconnor@blockstream.com::yGjaZvW2iOUiTcdJ:gR17 X-Hashcash: 1:25:180116:kalle.alm@gmail.com::jQhDG+PCGX4W7Kml:aT1UZ From: Luke Dashjr To: bitcoin-dev@lists.linuxfoundation.org, Rusty Russell Date: Tue, 16 Jan 2018 04:15:54 +0000 User-Agent: KMail/1.13.7 (Linux/4.14.13-gentoo; KDE/4.14.37; x86_64; ; ) References: <87608btgyd.fsf@rustcorp.com.au> <87zi5ehat5.fsf@rustcorp.com.au> In-Reply-To: <87zi5ehat5.fsf@rustcorp.com.au> X-PGP-Key-Fingerprint: E463 A93F 5F31 17EE DE6C 7316 BD02 9424 21F4 889F X-PGP-Key-ID: BD02942421F4889F X-PGP-Keyserver: hkp://pgp.mit.edu MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201801160415.55197.luke@dashjr.org> X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW, T_RP_MATCHES_RCVD autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Russell O'Connor , Kalle Alm Subject: Re: [bitcoin-dev] BIP 117 Feedback X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Jan 2018 04:17:22 -0000 On Tuesday 16 January 2018 1:06:14 AM Rusty Russell via bitcoin-dev wrote: > "Russell O'Connor" writes: > > However, if I understand correctly, the situation for BIP 117 is entirely > > different. As far as I understand there is currently no restrictions > > about terminating a v0 witness program with a non-empty alt-stack, and > > there are no restrictions on leaving non-canonical boolean values on the > > main stack. > > BIP-141: "The script must not fail, and result in exactly a single TRUE > on the stack." And it has long been non-standard for P2SH scripts to > not do the same (don't know exactly when). This doesn't affect the alt-stack (it's a completely separate stack). > The rule AFAICT is "standard transactions must still work". This was > violated with low-S, but the transformation was arguably trivial. > > OTOH, use of altstack is completely standard, though in practice it's > unused and so only a theoretical concern. I'm not aware of a single standard/BIP that uses the altstack at all. Luke