Since everyone's busy, I went ahead and made a pull request to add this as an informational BIP 79 to the bips directory.
https://github.com/bitcoin/bips/pull/157 Regards, Kristov On Tue, Jun 9, 2015 at 4:14 PM, Peter Todd <p...@petertodd.org> wrote: > On Mon, Jun 08, 2015 at 06:53:54PM -0400, Kristov Atlas wrote: > > Two other things: > > > > > On Sat, Jun 6, 2015 at 10:35 PM, Peter Todd <p...@petertodd.org> wrote: > > > > > Why mention SIGHASH_SINGLE at all? Its use-case is highly specialized > > > protocols; you haven't taken into account the needs of those protocols. > > > For BIP's it's better to stick to the use-cases where the need is clear > > > and there exists running code that to speculate too much on future > uses. > > > With signature hashing in particular it's not yet clear at all what > > > future OP_CHECKSIG's will look like, let alone the various ways people > > > will use sighash for smart contract type stuff. > > > > > > You'd be better off presenting the BIP in terms of a generic statement > > > that "except when otherwise prevented by advanced signature hashing > > > requirements, wallet software must emit transactions sorted according > to > > > the following" You can then specify the two common cases in detail: > > > > > > 1) SIGHASH_ALL: input and output order signed, so sort appropriately > > > > > > 2) SIGHASH_ANYONECANPAY: input order not signed, so software should > emit > > > transactions sorted, recognising that the actual mined order may be > > > changed. > > > > > > > That makes sense. I updated the language as follows -- your thoughts? > Keep > > in mind this BIP is informational, and so people are free to ignore it. > > > > "Applicability: This BIP applies to all transactions of signature hash > type > > SIGHASH_ALL. Additionally, software compliant with this BIP that allows > > later parties to update the transaction (e.g. using signature hash types > > SIGHASH_NONE or a variant of SIGHASH_ANYONECANPAY) should emit > > lexicographically sorted inputs and outputs, although they may later be > > modified. Transactions that have index dependencies between transactions > or > > within the same transaction are covered under the section of this BIP > > entitled “Handling Input/Output Dependencies.”" > > I'd keep it even simpler than that, and just say for now that such > use-cases are out of the scope of this BIP, however those standards > should come up with some kind of deterministic standard that meets the > needs of the protocol. Again, there's a bunch of possible use-cases here > and we just can't predict them; focus on the fact that the *spirit* of > what this BIP is about is applicable and future standards should be > developed. > > So I'd change the "Applicability" section to: > > This BIP applies to all transactions where the order of inputs and > outputs does not matter. This is true for the vast majority of > transactions as they simply move funds from one place to another. > > Currently this generally refers to transactions where SIGHASH_ALL is > used, in which case the signatures commit to the exact order of input > and outputs. In the case where SIGHASH_ANYONECANPAY and/or SIGHASH_NONE > has been used (e.g. crowdfunds) the order of inputs and/or outputs may > not be signed, however compliant software should still emit transactions > with sorted inputs and outputs, even though they may later be modified > by others. > > In the event that future protocol upgrades introduce new signature hash > types, compliant software should apply the lexographic ordering > principle analogously. > > While out of scope of this BIP, protocols that do require a specified > order of inputs/outputs (e.g. due to use of SIGHASH_SINGLE) should > consider the goals of this BIP and how best to adapt them to the > specifics needs of those protocols. > > > Then remove the "handling input/output deps" section. > > > > Do you have a patch implementing deterministic tx ordering for Bitcoin > > > Core yet? > > > > > > > I'm not a frequent C programmer, so I'd prefer to let someone else take > > care of it, as a frequent committer of code would do a faster and more > > stylistically consistent job of it. If no one else will, however, I will. > > > > re: the actual ordering algorithm, having txids be sorted by with the > hex-based algorithm is odd. I'd simply say they're sorted as > little-endian byte arrays, or in other words, with the bytearr_cmp() > function, but with the order of bytes reversed. You also should say that > we're doing that to make the user see them in visually sorted order to > match expectations because txids are displayed as little-endian. > > For outputs, don't say "locking script", say "scriptPubKey". Secondly, > scriptPubKeys are not in little-endian representation - they have no > endianness to them. With output amount, there's no need to say that > they're unsigned or little-endian satoshies, just say they're sorted > largest/smallest amount first. > > "For the sake of efficiency, amounts will be considered first for > sorting, since they contain fewer bytes of information (7 bytes) > compared to a standard P2PKH locking script (800 bytes)." <- where the > heck did you get these numbers from? Amounts are 8 bytes, and P2PKH > scriptPubKeys are 25 bytes. > > > "Backwards Compatibility" <- I'd just remove this whole section; we're > unlikely to make this an IsStandard() rule anytime soon. > > -- > 'peter'[:-1]@petertodd.org > 0000000000000000127ab1d576dc851f374424f1269c4700ccaba2c42d97e778 >
_______________________________________________ Bitcoin-development mailing list Bitcoinemail@example.com https://lists.sourceforge.net/lists/listinfo/bitcoin-development