Hi Rusty, On 1/6/21 6:26 PM, Rusty Russell wrote: > Hi Andrew et al, > > Very excited to see this progress; thanks for doing all the > work! Sorry for the delayed feedback, I didn't get to this before the > break. > >> Additionally, I would like to add a new global field: >> * PSBT_GLOBAL_UNDER_CONSTRUCTION = 0x05 >> * Key: empty >> * Value: A single byte as a boolean. 0 for False, 1 for True. All >> other values ore prohibited. Must be omitted for PSBTv0, may be omitted >> in PSBTv2. >> >> PSBT_GLOBAL_UNDER_CONSTRUCTION is used to signal whether inputs and >> outputs can be added to the PSBT. This flag may be set to True when >> inputs and outputs are being updated, signed, and finalized. However >> care must be taken when there are existing signatures. If this field is >> omitted or set to False, no further inputs and outputs may be added to >> the PSBT. > I wonder if this can be flagged simply by omitting the (AFAICT > redundant) PSBT_GLOBAL_INPUT_COUNT and PSBT_GLOBAL_OUTPUT_COUNT? What > are the purposes of those fields? The purpose of those fields is to know how many input and output maps there are. Without PSBT_GLOBAL_UNSIGNED_TX, there is no way to determine whether a map is an input map or an output map. So the counts are there to allow that. > For our uses, there would be no signatures at this stage; it's simply a > subdivision of the Creator role. This role would be terminated by > removing the under-construction marker. For this, it could be clear > that such an under-construction PSBT SHOULD NOT be signed. There are some protocols where signed inputs are added to transactions. > Otherwise, if an explicit marker is required, I would omit the value and > simply use its existence to as a flag. Having two "false" values is > simply asking for trouble. Seems reasonable.
Andrew > Thanks! > Rusty. > PS. Perhaps we should change the name to PBT (Partial Bitcoin > Transaction) now, since it's more than just signing... _______________________________________________ bitcoin-dev mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
