8088eddc534cbbb89dd5f892828c4013416c4f2b musig: add test vector for ordinary (non xonly) tweaking (Elliott Jin)
57a17929fc0056efb5436a6001597d656591e1ad musig: add ordinary and xonly tweaking to the example (Jonas Nick)
37107361a0ff3b8764903e3b384cfc12ed484e7a musig: allow ordinary, non-xonly tweaking (Jonas Nick)
c519b468791670654f8b66368a675655cd337ae8 musig: add pubkey_get to obtain a full pubkey from a keyagg_cache (Jonas Nick)
Pull request description:
In short, `musig_pubkey_tweak_add` now allows for xonly _and_ "ordinary" tweaking. Also, in order to allow using `ec_pubkey_tweak_add` on the non-xonly aggregate public key, there's a new function `musig_pubkey_get` that allows obtaining it from the `keyagg_cache`.
One alternative would be that instead of adding `musig_pubkey_get`, we could change `pubkey_agg` to output an ordinary (non-xonly) pubkey. Then users of the API who do not need ordinary (BIP32) tweaking would be forced to call `xonly_pubkey_from_pubkey`. And we'd probably want to change the spec. And it would be a bit weird to output a pubkey that can't be directly schnorrsig_verify'd.
Based on #131
ACKs for top commit:
robot-dreams:
ACK 8088eddc534cbbb89dd5f892828c4013416c4f2b based on https://github.com/ElementsProject/secp256k1-zkp/pull/151#issuecomment-1005198409 and the following `range-diff`:
Tree-SHA512: a4a0100f0470c870f88a8da27dbcc4684fcc2caabb368d4340e962e08d5ee04634e6289bafa3448dbfd0b5793a3e70de5bd6ddca7a619cc3220ff762d518a8fe
772df3694e