Merge pull request #34 from apoelstra/segwit-txid

transaction: add txid() method

Cargo.toml

@@ -1,7 +1,7 @@
 
 [package]
 name = "bitcoin"
-version = "0.10.3"
+version = "0.10.4"
 authors = ["Andrew Poelstra <apoelstra@wpsoftware.net>"]
 license = "CC0-1.0"
 homepage = "https://github.com/apoelstra/rust-bitcoin/"

src/blockdata/transaction.rs

@@ -116,6 +116,21 @@ impl Transaction {
         cloned_tx.bitcoin_hash()
     }
 
+    /// Computes the txid. For non-segwit transactions this will be identical
+    /// to the output of `BitcoinHash::bitcoin_hash()`, but for segwit transactions,
+    /// this will give the correct txid (not including witnesses) while `bitcoin_hash`
+    /// will also hash witnesses.
+    pub fn txid(&self) -> Sha256dHash {
+        use util::hash::Sha256dEncoder;
+
+        let mut enc = Sha256dEncoder::new();
+        self.version.consensus_encode(&mut enc).unwrap();
+        self.input.consensus_encode(&mut enc).unwrap();
+        self.output.consensus_encode(&mut enc).unwrap();
+        self.lock_time.consensus_encode(&mut enc).unwrap();
+        enc.into_hash()
+    }
+
     /// Computes a signature hash for a given input index with a given sighash flag.
     /// To actually produce a scriptSig, this hash needs to be run through an
     /// ECDSA signer, the SigHashType appended to the resulting sig, and a
@@ -383,6 +398,59 @@ mod tests {
         assert!(old_ntxid != tx.ntxid());
     }
 
+    #[test]
+    fn test_txid() {
+        // segwit tx from Liquid integration tests, txid/hash from Core decoderawtransaction
+        let hex_tx = hex_bytes(
+            "01000000000102ff34f95a672bb6a4f6ff4a7e90fa8c7b3be7e70ffc39bc99be3bda67942e836c00000000\
+             23220020cde476664d3fa347b8d54ef3aee33dcb686a65ced2b5207cbf4ec5eda6b9b46e4f414d4c934ad8\
+             1d330314e888888e3bd22c7dde8aac2ca9227b30d7c40093248af7812201000000232200200af6f6a071a6\
+             9d5417e592ed99d256ddfd8b3b2238ac73f5da1b06fc0b2e79d54f414d4c0ba0c8f505000000001976a914\
+             dcb5898d9036afad9209e6ff0086772795b1441088ac033c0f000000000017a914889f8c10ff2bd4bb9dab\
+             b68c5c0d700a46925e6c87033c0f000000000017a914889f8c10ff2bd4bb9dabb68c5c0d700a46925e6c87\
+             033c0f000000000017a914889f8c10ff2bd4bb9dabb68c5c0d700a46925e6c87033c0f000000000017a914\
+             889f8c10ff2bd4bb9dabb68c5c0d700a46925e6c87033c0f000000000017a914889f8c10ff2bd4bb9dabb6\
+             8c5c0d700a46925e6c87033c0f000000000017a914889f8c10ff2bd4bb9dabb68c5c0d700a46925e6c8703\
+             3c0f000000000017a914889f8c10ff2bd4bb9dabb68c5c0d700a46925e6c87033c0f000000000017a91488\
+             9f8c10ff2bd4bb9dabb68c5c0d700a46925e6c87033c0f000000000017a914889f8c10ff2bd4bb9dabb68c\
+             5c0d700a46925e6c87033c0f000000000017a914889f8c10ff2bd4bb9dabb68c5c0d700a46925e6c870500\
+             47304402200380b8663e727d7e8d773530ef85d5f82c0b067c97ae927800a0876a1f01d8e2022021ee611e\
+             f6507dfd217add2cd60a8aea3cbcfec034da0bebf3312d19577b8c290147304402207bd9943ce1c2c5547b\
+             120683fd05d78d23d73be1a5b5a2074ff586b9c853ed4202202881dcf435088d663c9af7b23efb3c03b9db\
+             c0c899b247aa94a74d9b4b3c84f501483045022100ba12bba745af3f18f6e56be70f8382ca8e107d1ed5ce\
+             aa3e8c360d5ecf78886f022069b38ebaac8fe6a6b97b497cbbb115f3176f7213540bef08f9292e5a72de52\
+             de01695321023c9cd9c6950ffee24772be948a45dc5ef1986271e46b686cb52007bac214395a2102756e27\
+             cb004af05a6e9faed81fd68ff69959e3c64ac8c9f6cd0e08fd0ad0e75d2103fa40da236bd82202a985a910\
+             4e851080b5940812685769202a3b43e4a8b13e6a53ae050048304502210098b9687b81d725a7970d1eee91\
+             ff6b89bc9832c2e0e3fb0d10eec143930b006f02206f77ce19dc58ecbfef9221f81daad90bb4f468df3912\
+             12abc4f084fe2cc9bdef01483045022100e5479f81a3ad564103da5e2ec8e12f61f3ac8d312ab68763c1dd\
+             d7bae94c20610220789b81b7220b27b681b1b2e87198897376ba9d033bc387f084c8b8310c8539c2014830\
+             45022100aa1cc48a2d256c0e556616444cc08ae4959d464e5ffff2ae09e3550bdab6ce9f02207192d5e332\
+             9a56ba7b1ead724634d104f1c3f8749fe6081e6233aee3e855817a016953210260de9cc68658c61af984e3\
+             ab0281d17cfca1cc035966d335f474932d5e6c5422210355fbb768ce3ce39360277345dbb5f376e706459e\
+             5a2b5e0e09a535e61690647021023222ceec58b94bd25925dd9743dae6b928737491bd940fc5dd7c6f5d5f\
+             2adc1e53ae00000000"
+        ).unwrap();
+        let tx: Transaction = deserialize(&hex_tx).unwrap();
+
+        assert_eq!(tx.bitcoin_hash().be_hex_string(), "d6ac4a5e61657c4c604dcde855a1db74ec6b3e54f32695d72c5e11c7761ea1b4");
+        assert_eq!(tx.txid().be_hex_string(), "9652aa62b0e748caeec40c4cb7bc17c6792435cc3dfe447dd1ca24f912a1c6ec");
+
+        // non-segwit tx from my mempool
+        let hex_tx = hex_bytes(
+            "01000000010c7196428403d8b0c88fcb3ee8d64f56f55c8973c9ab7dd106bb4f3527f5888d000000006a47\
+             30440220503a696f55f2c00eee2ac5e65b17767cd88ed04866b5637d3c1d5d996a70656d02202c9aff698f\
+             343abb6d176704beda63fcdec503133ea4f6a5216b7f925fa9910c0121024d89b5a13d6521388969209df2\
+             7a8469bd565aff10e8d42cef931fad5121bfb8ffffffff02b825b404000000001976a914ef79e7ee9fff98\
+             bcfd08473d2b76b02a48f8c69088ac0000000000000000296a273236303039343836393731373233313237\
+             3633313032313332353630353838373931323132373000000000"
+        ).unwrap();
+        let tx: Transaction = deserialize(&hex_tx).unwrap();
+
+        assert_eq!(tx.bitcoin_hash().be_hex_string(), "971ed48a62c143bbd9c87f4bafa2ef213cfa106c6e140f111931d0be307468dd");
+        assert_eq!(tx.txid().be_hex_string(), "971ed48a62c143bbd9c87f4bafa2ef213cfa106c6e140f111931d0be307468dd");
+    }
+
     #[test]
     fn test_txn_encode_decode() {
         let hex_tx = hex_bytes("0100000001a15d57094aa7a21a28cb20b59aab8fc7d1149a3bdbcddba9c622e4f5f6a99ece010000006c493046022100f93bb0e7d8db7bd46e40132d1f8242026e045f03a0efe71bbb8e3f475e970d790221009337cd7f1f929f00cc6ff01f03729b069a7c21b59b1736ddfee5db5946c5da8c0121033b9b137ee87d5a812d6f506efdd37f0affa7ffc310711c06c7f3e097c9447c52ffffffff0100e1f505000000001976a9140389035a9225b3839e2bbf32d826a1e222031fd888ac00000000").unwrap();