BIP 340 & 341: use consistent definition of lift_x #1355

1. 
   jonasnick commented at 3:09 pm on August 16, 2022: contributor

   As pointed out by @Randy808 here.

   CC @sipa @ajtowns

2. BIP 341: add missing conversion from bytes to int 2119931f01
3. 
   jonasnick commented at 7:09 pm on August 19, 2022: contributor

   I noticed that this PR alone does not fix the problem: lift_x has different definitions in the BIP-340 mediawiki specification and the reference code. The first commit in this PR makes taproot_tweak_pubkey correct with respect to lift_x in the mediawiki spec but incorrect wrt the reference code. I think the best option is to harmonize both definitions lift_x and added a commit that changes lift_x in the reference code.

   CC @real-or-random

4. jonasnick renamed this:
   BIP 341: add missing conversion from bytes to int
   BIP 340 & 341: use consistent definition of lift_x
   on Aug 19, 2022
5. 
   real-or-random commented at 8:42 am on August 20, 2022: contributor

   tACK

   Should we add a Changelog that tracks (non-trivial) changes? I think it won’t hurt but I’m not convinced that it’s worth the effort. The git log may be good enough to be honest. https://github.com/bitcoin/bips/commits/master?before=64aba767e2d422b5d471509acc340750432613ae+35&branch=master&path%5B%5D=bip-0340.mediawiki&qualified_name=refs%2Fheads%2Fmaster We’d need to decide on when to start it, maybe pragmatically after https://github.com/bitcoin/bips/commit/3b1fb9600b938172dd98a63e4906a861af9c3ab0?

   As pointed out by @Randy808 here. wrong link target?

6. 
   jonasnick commented at 1:41 pm on August 20, 2022: contributor

   Sorry, fixed the link.
7. haleemshal approved
8. jonasnick force-pushed on Aug 23, 2022
9. 
   jonasnick commented at 10:05 am on August 23, 2022: contributor

   Added a changelog akin to https://github.com/sipa/bips/pull/221.
10. BIP 340: fix function signature of lift_x in reference code

    bip-0340.mediawiki defines lift_x as taking an integer argument. This commit
    changes the argument of lift_x in the reference code to be identical to the
    specification. Previously it took a byte array.

    3998dbbc8a
11. 
    sipa commented at 2:29 pm on August 23, 2022: member

    ACK 3998dbbc8a3ab3bfabb1b2e90a4840ad93a84adb
12. real-or-random approved
13. 
    real-or-random commented at 3:04 pm on August 23, 2022: contributor

    ACK 3998dbbc8a3ab3bfabb1b2e90a4840ad93a84adb
14. 
    real-or-random commented at 3:05 pm on August 23, 2022: contributor

    Ok let’s get this merged here now that we have the ACKs and then we can batch-PR a few more changes here later (which are currently only PRed to @sipa’s fork).
15. kallewoof merged this on Aug 25, 2022
16. kallewoof closed this on Aug 25, 2022

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17. 
    jackromo888 commented at 11:43 pm on August 31, 2022: none
18. 
    jackromo888 commented at 11:43 pm on August 31, 2022: none

    https://github.com/bitcoin/bips/commit/52f68fecd8ec9604672e26392468e7e7edf25a5ehttps://github.com/bitcoin/bips/commit/52f68fecd8ec9604672e26392468e7e7edf25a5e

Contributors
jonasnick real-or-random haleemshal sipa jackromo888