Add a simple way to generate taproot from a public key

Author: mohanson

example/regtest.py

@@ -25,6 +25,5 @@
 pabtc.rpc.generate_to_address(10, pabtc.core.Address.p2sh_p2ms(2, [pub1, pub2]))
 pabtc.rpc.generate_to_address(10, pabtc.core.Address.p2sh_p2wpkh(pub1.hash()))
 pabtc.rpc.generate_to_address(10, pabtc.core.Address.p2wpkh(pub1.hash()))
-p2tr_pubkey = bytearray(pabtc.taproot.pubkey_tweak(pub1.pt(), bytearray()).x.n.to_bytes(32))
-pabtc.rpc.generate_to_address(10, pabtc.core.Address.p2tr(p2tr_pubkey))
+pabtc.rpc.generate_to_address(10, pabtc.core.Address.p2tr(pub1.tr(bytearray())))
 pabtc.rpc.generate_to_address(99, pabtc.core.Address.p2pkh(pub1.hash()))

example/taproot.py

@@ -14,8 +14,7 @@
 class Signerp2trp2pk(pabtc.wallet.Signer):
     def __init__(self, pubkey: pabtc.core.PubKey) -> None:
         self.pubkey = pubkey
-        p2tr_pubkey = bytearray(pabtc.taproot.pubkey_tweak(pubkey.pt(), mast.hash).x.n.to_bytes(32))
-        self.addr = pabtc.core.Address.p2tr(p2tr_pubkey)
+        self.addr = pabtc.core.Address.p2tr(pubkey.tr(mast.hash))
         self.script = pabtc.core.ScriptPubKey.address(self.addr)
         output_pubkey_byte = bytearray(
             [0x02]) + pabtc.bech32.decode_segwit_addr(pabtc.config.current.prefix.bech32, 1, self.addr)
@@ -41,8 +40,7 @@ def sign(self, tx: pabtc.core.Transaction) -> None:
 class Signerp2trp2ms(pabtc.wallet.Signer):
     def __init__(self, pubkey: pabtc.core.PubKey) -> None:
         self.pubkey = pubkey
-        p2tr_pubkey = bytearray(pabtc.taproot.pubkey_tweak(pubkey.pt(), mast.hash).x.n.to_bytes(32))
-        self.addr = pabtc.core.Address.p2tr(p2tr_pubkey)
+        self.addr = pabtc.core.Address.p2tr(pubkey.tr(mast.hash))
         self.script = pabtc.core.ScriptPubKey.address(self.addr)
         output_pubkey_byte = bytearray(
             [0x02]) + pabtc.bech32.decode_segwit_addr(pabtc.config.current.prefix.bech32, 1, self.addr)

pabtc/core.py

@@ -199,6 +199,11 @@ def sec_decode(cls, data: bytearray) -> PubKey:
                 y = -y % pabtc.secp256k1.P
         return PubKey(x, y)
 
+    def tr(self, merkle: bytearray) -> bytearray:
+        # Get the taproot output key corresponding to the internal public key and the taproot tree merkle root.
+        assert len(merkle) == 32
+        return bytearray(pabtc.taproot.pubkey_tweak(self.pt(), merkle).x.n.to_bytes(32))
+
 
 class ScriptPubKey:
     # The Script pubkey is the locking code for an output. It's made up of script, which is a mini programming language