test: add coverage for parsing cryptographically invalid pubkeys

test/functional/wallet_basic.py

@@ -461,9 +461,11 @@ def run_test(self):
             # This will raise an exception for attempting to import a pubkey that isn't in hex
             assert_raises_rpc_error(-5, 'Pubkey "not hex" must be a hex string', self.nodes[0].importpubkey, "not hex")
 
-            # This will raise an exception for importing a pubkey with invalid length
+            # This will raise exceptions for importing a pubkeys with invalid length / invalid coordinates
             too_short_pubkey = "5361746f736869204e616b616d6f746f"
             assert_raises_rpc_error(-5, f'Pubkey "{too_short_pubkey}" must have a length of either 33 or 65 bytes', self.nodes[0].importpubkey, too_short_pubkey)
+            not_on_curve_pubkey = bytes([4] + [0]*64).hex()  # pubkey with coordinates (0,0) is not on curve
+            assert_raises_rpc_error(-5, f'Pubkey "{not_on_curve_pubkey}" must be cryptographically valid', self.nodes[0].importpubkey, not_on_curve_pubkey)
 
             # Bech32m addresses cannot be imported into a legacy wallet
             assert_raises_rpc_error(-5, "Bech32m addresses cannot be imported into legacy wallets", self.nodes[0].importaddress, "bcrt1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vqc8gma6")