Fix p2tr spend/change bug

src/seedsigner/models/psbt_parser.py

@@ -148,7 +148,7 @@ def _parse_outputs(self):
                         leaf_hashes, derivation = list(out.taproot_bip32_derivations.values())[0]
                         der = derivation.derivation
                         my_pubkey = self.root.derive(der)
-                    sc = script.p2tr(my_pubkey)
+                        sc = script.p2tr(my_pubkey)
 
                     if sc.data == self.psbt.tx.vout[i].script_pubkey.data:
                         is_change = True

tests/test_psbt_parser.py

@@ -1,8 +1,47 @@
 import pytest
 from mock import MagicMock
-from seedsigner.models import PSBTParser
+from seedsigner.models import PSBTParser, Seed
 from embit import psbt
+from binascii import a2b_base64
+from seedsigner.models.settings_definition import SettingsConstants
 
-def test_sig_count():
-	print("test")
-
+def test_p2tr_change_detection():
+	""" Should successfully detect change in a p2tr to p2tr psbt spend
+
+		PSBT Tx and Wallet Details
+		- Single Sig Wallet P2TR (Taproot) with no passphrase
+		- Regtest 394aed14 m/86'/1'/0' tpubDCawGrRg7YdHdFb9p4mmD8GBaZjJegL53FPFRrMkGoLcgLATJfksUs2y1Q7dVzixAkgecazsxEsUuyj3LyDw7eVVYHQyojwrc2hfesK4wXW
+		- 1 Inputs
+			- 3,190,493,401 sats
+		- 2 Outputs
+			- 1 Output spend to another wallet (bcrt1p6p00wazu4nnqac29fvky6vhjnnhku5u2g9njss62rvy7e0yuperq86f5ek) p2tr address
+			- 1 Output change
+				- addresss bcrt1prz4g6saush37epdwhvwpu78td3q7yfz3xxz37axlx7udck6wracq3rwq30)
+				- amount 2,871,443,918 sats
+				- Change addresses is index 1/1
+			- Fee 155 sats
+	"""
+
+	psbt_base64 = "cHNidP8BAIkCAAAAAf8upuiIWF1VTgC/Q8ZWRrameRigaXpRcQcBe8ye+TK3AQAAAAAXCgAAAs7BJqsAAAAAIlEgGKqNQ7yF4+yFrrscHnjrbEHiJFExhR903ze43FtOH3BwTgQTAAAAACJRINBe93RcrOYO4UVLLE0y8pzvblOKQWcoQ0obCey8nA5GAAAAAE8BBDWHzwNMUx9OgAAAAJdr+WtwWfVa6IPbpKZ4KgRC0clbm11Gl155IPA27n2FAvQCrFGH6Ac2U0Gcy1IH5f5ltgUBDz2+fe8iqL6JzZdgEDlK7RRWAACAAQAAgAAAAIAAAQB9AgAAAAGAKOOUFIzw9pbRDaZ7F0DYhLImrdMn//OSm++ff5VNdAAAAAAAAQAAAAKsjLwAAAAAABYAFKEcuxvXmB3rWHSqSviP5mrKMZoL2RArvgAAAAAiUSBGU0Lg5fx/ECsB1Z4ZUqXQFSLFnlmpm0rm5R2l599h2AAAAAABASvZECu+AAAAACJRIEZTQuDl/H8QKwHVnhlSpdAVIsWeWambSublHaXn32HYAQMEAAAAACEWF7hZVn7pIDR429kAn/WDeQiWjZey1iGHztsL1H83QLMZADlK7RRWAACAAQAAgAAAAIABAAAAAAAAAAEXIBe4WVZ+6SA0eNvZAJ/1g3kIlo2XstYhh87bC9R/N0CzACEHbJdqWyMxF2eOPr6YRXUJmry04HUbgKyeM2IZeG+NI9AZADlK7RRWAACAAQAAgAAAAIABAAAAAQAAAAEFIGyXalsjMRdnjj6+mEV1CZq8tOB1G4CsnjNiGXhvjSPQAAA="
+
+	raw = a2b_base64(psbt_base64)
+	tx = psbt.PSBT.parse(raw)
+
+	mnemonic = "goddess rough corn exclude cream trial fee trumpet million prevent gaze power".split()
+	pw = ""
+	seed = Seed(mnemonic, passphrase=pw)
+
+	pp = PSBTParser(p=tx, seed=seed, network=SettingsConstants.REGTEST)
+
+	assert pp.change_data == [
+		{
+			'output_index': 0,
+			'address': 'bcrt1prz4g6saush37epdwhvwpu78td3q7yfz3xxz37axlx7udck6wracq3rwq30',
+			'amount': 2871443918,
+			'fingerprint': ['394aed14'],
+			'derivation_path': ['m/86h/1h/0h/1/1']}
+		]
+	assert pp.spend_amount == 319049328
+	assert pp.change_amount == 2871443918
+	assert pp.destination_addresses == ['bcrt1p6p00wazu4nnqac29fvky6vhjnnhku5u2g9njss62rvy7e0yuperq86f5ek']
+	assert pp.destination_amounts == [319049328]