signet: miner skips PSBT step for OP_TRUE

test/functional/test_framework/blocktools.py

@@ -80,6 +80,9 @@ DIFF_4_N_BITS = 0x1c3fffc0
 DIFF_4_TARGET = int(DIFF_1_TARGET / 4)
 assert_equal(uint256_from_compact(DIFF_4_N_BITS), DIFF_4_TARGET)
 
+# From BIP325
+SIGNET_HEADER = b"\xec\xc7\xda\xa2"
+
 def nbits_str(nbits):
     return f"{nbits:08x}"
 

test/functional/tool_signet_miner.py

@@ -10,9 +10,9 @@ import subprocess
 import sys
 import time
 
-from test_framework.blocktools import DIFF_1_N_BITS
+from test_framework.blocktools import DIFF_1_N_BITS, SIGNET_HEADER
 from test_framework.key import ECKey
-from test_framework.script_util import key_to_p2wpkh_script
+from test_framework.script_util import CScript, key_to_p2wpkh_script
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
@@ -23,31 +23,49 @@ from test_framework.wallet_util import bytes_to_wif
 
 CHALLENGE_PRIVATE_KEY = (42).to_bytes(32, 'big')
 
+def get_segwit_commitment(node):
+    coinbase = node.getblock(node.getbestblockhash(), 2)['tx'][0]
+    commitment = coinbase['vout'][1]['scriptPubKey']['hex']
+    assert_equal(commitment[0:12], '6a24aa21a9ed')
+    return commitment
+
+def get_signet_commitment(segwit_commitment):
+    for el in CScript.fromhex(segwit_commitment):
+        if isinstance(el, bytes) and el[0:4] == SIGNET_HEADER:
+            return el[4:].hex()
+    return None
 
 class SignetMinerTest(BitcoinTestFramework):
     def set_test_params(self):
         self.chain = "signet"
         self.setup_clean_chain = True
-        self.num_nodes = 1
+        self.num_nodes = 4
 
         # generate and specify signet challenge (simple p2wpkh script)
         privkey = ECKey()
         privkey.set(CHALLENGE_PRIVATE_KEY, True)
         pubkey = privkey.get_pubkey().get_bytes()
         challenge = key_to_p2wpkh_script(pubkey)
-        self.extra_args = [[f'-signetchallenge={challenge.hex()}']]
+
+        self.extra_args = [
+            [f'-signetchallenge={challenge.hex()}'],
+            ["-signetchallenge=51"], # OP_TRUE
+            ["-signetchallenge=60"], # OP_16
+            ["-signetchallenge=202cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"], # sha256("hello")
+        ]
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_cli()
         self.skip_if_no_wallet()
         self.skip_if_no_bitcoin_util()
 
-    def run_test(self):
-        node = self.nodes[0]
-        # import private key needed for signing block
-        wallet_importprivkey(node, bytes_to_wif(CHALLENGE_PRIVATE_KEY), "now")
+    def setup_network(self):
+        self.setup_nodes()
+        # Nodes with different signet networks are not connected
 
-        # generate block with signet miner tool
+    # generate block with signet miner tool
+    def mine_block(self, node):
+        n_blocks = node.getblockcount()
         base_dir = self.config["environment"]["SRCDIR"]
         signet_miner_path = os.path.join(base_dir, "contrib", "signet", "miner")
         rpc_argv = node.binaries.rpc_argv() + [f"-datadir={node.cli.datadir}"]
@@ -63,7 +81,34 @@ class SignetMinerTest(BitcoinTestFramework):
                 f'--set-block-time={int(time.time())}',
                 '--poolnum=99',
             ], check=True, stderr=subprocess.STDOUT)
-        assert_equal(node.getblockcount(), 1)
+        assert_equal(node.getblockcount(), n_blocks + 1)
+
+    def run_test(self):
+        self.log.info("Signet node with single signature challenge")
+        node = self.nodes[0]
+        # import private key needed for signing block
+        wallet_importprivkey(node, bytes_to_wif(CHALLENGE_PRIVATE_KEY), 0)
+        self.mine_block(node)
+        # MUST include signet commitment
+        assert get_signet_commitment(get_segwit_commitment(node))
+
+        node = self.nodes[1]
+        self.log.info("Signet node with trivial challenge (OP_TRUE)")
+        self.mine_block(node)
+        # MAY omit signet commitment (BIP 325). Do so for better compatibility
+        # with signet unaware mining software and hardware.
+        assert get_signet_commitment(get_segwit_commitment(node)) is None
+
+        node = self.nodes[2]
+        self.log.info("Signet node with trivial challenge (OP_16)")
+        self.mine_block(node)
+        assert get_signet_commitment(get_segwit_commitment(node)) is None
+
+        node = self.nodes[3]
+        self.log.info("Signet node with trivial challenge (push sha256 hash)")
+        self.mine_block(node)
+        assert get_signet_commitment(get_segwit_commitment(node)) is None
+
 
 
 if __name__ == "__main__":