Re: [bitcoin-dev] Dealing with OP_IF and OP_NOTIF malleability

[jl2012@xbt.hk]

I assume this proposal is implemented at the same time as BIP62. As long 
as OP_IF/OP_NOTIF interprets the argument as a number, zero-padded 
number and negative zero are already prohibited in BIP62

Tier Nolan via bitcoin-dev 於 2015-11-06 04:37 寫到:
> I meant not to use the OP_PUSH opcodes to do the push.
> 
> Does OP_0 give a zero length byte array?
> 
> Would this script return true?
> 
> OP_0
> 
> OP_PUSHDATA1 (length = 1, data = 0)
> 
> OP_EQUAL
> 
> The easiest definition is that OP_0 and OP_1 must be used to push the
> data and not any other push opcodes.
> 
> On Fri, Nov 6, 2015 at 9:32 AM, Oleg Andreev <oleganza@gmail.com>
> wrote:
> 
>>> One and zero should be defined as arrays of length one.
>> Otherwise, it is still possible to mutate the transaction by
>> changing the length of the array.
>>> 
>>> They should also be minimally encoded but that is covered by
>> previous rules.
>> 
>> These two lines contradict each other. Minimally-encoded "zero" is
>> an array of length zero, not one. I'd suggest defining this
>> explicitly here as "IF/NOTIF argument must be either zero-length
>> array or a single byte 0x01".
> 
> 
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev