Add taproot checks to Address::from_script

src/util/address.rs

@@ -671,7 +671,24 @@ impl Address {
     }
 
     /// Constructs an [`Address`] from an output script (`scriptPubkey`).
+    ///
+    /// # Returns
+    ///
+    /// The Bitcoin network allows well formed addresses that are unspendable, such as an address
+    /// created from an invalid script. We explicitly make an effort to protect users and do not
+    /// create such addresses, hence if `script` is a segwit script but is _invalid_ we do not
+    /// create an address and instead return `None`.
     pub fn from_script(script: &script::Script, network: Network) -> Option<Address> {
+        if script.is_witness_program() {
+            if script.witness_version() == Some(WitnessVersion::V0) && !(script.is_v0_p2wpkh() || script.is_v0_p2wsh()) {
+                return None
+            }
+
+            if script.witness_version() == Some(WitnessVersion::V1) && !script.is_v1_p2tr() {
+                return None
+            }
+        }
+
         Some(Address {
             payload: Payload::from_script(script)?,
             network,
@@ -1089,20 +1106,26 @@ mod tests {
     #[test]
     fn test_bip173_350_vectors() {
         // Test vectors valid under both BIP-173 and BIP-350
+        //
+        // We intentionally do not support creating an address from a _currently_ invalid script,
+        // however we do support addresses that contain currently invalid scripts (i.e, allowed for
+        // future extensions). This means that not all test vectors will roundtrip.
         let valid_vectors = [
-            ("BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4", "0014751e76e8199196d454941c45d1b3a323f1433bd6"),
-            ("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7", "00201863143c14c5166804bd19203356da136c985678cd4d27a1b8c6329604903262"),
-            ("bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kt5nd6y", "5128751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd6"),
-            ("BC1SW50QGDZ25J", "6002751e"),
-            ("bc1zw508d6qejxtdg4y5r3zarvaryvaxxpcs", "5210751e76e8199196d454941c45d1b3a323"),
-            ("tb1qqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesrxh6hy", "0020000000c4a5cad46221b2a187905e5266362b99d5e91c6ce24d165dab93e86433"),
-            ("tb1pqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesf3hn0c", "5120000000c4a5cad46221b2a187905e5266362b99d5e91c6ce24d165dab93e86433"),
-            ("bc1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vqzk5jj0", "512079be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798")
+            ("BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4", "0014751e76e8199196d454941c45d1b3a323f1433bd6", true),
+            ("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7", "00201863143c14c5166804bd19203356da136c985678cd4d27a1b8c6329604903262", true),
+            ("bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kt5nd6y", "5128751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd6", false),
+            ("BC1SW50QGDZ25J", "6002751e", true),
+            ("bc1zw508d6qejxtdg4y5r3zarvaryvaxxpcs", "5210751e76e8199196d454941c45d1b3a323", true),
+            ("tb1qqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesrxh6hy", "0020000000c4a5cad46221b2a187905e5266362b99d5e91c6ce24d165dab93e86433", true),
+            ("tb1pqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesf3hn0c", "5120000000c4a5cad46221b2a187905e5266362b99d5e91c6ce24d165dab93e86433", true),
+            ("bc1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vqzk5jj0", "512079be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798", true)
         ];
         for vector in &valid_vectors {
             let addr: Address = vector.0.parse().unwrap();
             assert_eq!(&addr.script_pubkey().as_bytes().to_hex(), vector.1);
-            roundtrips(&addr);
+            if vector.2 {
+                roundtrips(&addr);
+            }
         }
 
         let invalid_vectors = [
@@ -1398,4 +1421,15 @@ mod tests {
         let result = address.is_related_to_xonly_pubkey(&xonly_pubkey);
         assert!(result);
     }
+
+    #[test]
+    fn test_fail_address_from_script() {
+        let bad_p2wpkh = hex_script!("0014dbc5b0a8f9d4353b4b54c3db48846bb15abfec");
+        let bad_p2wsh = hex_script!("00202d4fa2eb233d008cc83206fa2f4f2e60199000f5b857a835e3172323385623");
+        let bad_p2tr = hex_script!("5128751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd6");
+
+        assert_eq!(Address::from_script(&bad_p2wpkh, Network::Bitcoin), None);
+        assert_eq!(Address::from_script(&bad_p2wsh, Network::Bitcoin), None);
+        assert_eq!(Address::from_script(&bad_p2tr, Network::Bitcoin), None);
+    }
 }