Jonathan Underwood

This is the mid-state for `"TapTweak"` ``` sha->s[0] = 0xd129a2f3ul; sha->s[1] = 0x701c655dul; sha->s[2] = 0x6583b6c3ul; sha->s[3] = 0xb9419727ul; sha->s[4] = 0x95f4e232ul; sha->s[5] = 0x94fd54f4ul; sha->s[6] = 0xa2ae8d85ul; sha->s[7] =...

This is a very rough implementation, but something like this maybe? https://github.com/bitcoin-core/secp256k1/compare/ea5e8a9...junderw:feature/secp256k1_schnorrsig_sign_with_taptweak_preimage

> Hm, can you elaborate? > I don't really see what the issue is with having this logic in the calling code Sure thing. (collapsing because it's long and slightly...

@sipa I see the `ComputeTapTweakHash` call now... (coming from higher level languages, `if (merkle_root)` looks like it will not go into the if scope, but then I just saw `merkle_root->IsNull()...

(Though I still do believe the helper function would be useful, and would take a burden off the caller when signing for a tweaked key)

> Right, that's what I meant. (re: It being more foot-cannon prone) I think this is all the more reason to include the tweak helper function for signing (sign_with_tweak). Because...

I will make a separate issue for keypair serialization though.

Rust code is encoding the private key into 64 hex characters (32 bytes) I still think keypair should be 96 bytes of private, x, y.

Using WASM, requiring a re-calculation of the pubkey every time you cross the JS/WASM boundary is inefficient, it would be better to have and explicit serialization format to allow for...

Maybe just "Copy .onion address 📋" since idk if a non-onion browser can open onion links properly. ... or maybe there should just be a dedicated page to hidden service...