script: add `is_p2pkh()` function

Cargo.toml

@@ -1,7 +1,7 @@
 
 [package]
 name = "bitcoin"
-version = "0.10.0"
+version = "0.10.1"
 authors = ["Andrew Poelstra <apoelstra@wpsoftware.net>"]
 license = "CC0-1.0"
 homepage = "https://github.com/apoelstra/rust-bitcoin/"

src/blockdata/script.rs

@@ -264,6 +264,17 @@ impl Script {
         self.0[22] == opcodes::All::OP_EQUAL as u8
     }
 
+    /// Checks whether a script pubkey is a p2pkh output
+    #[inline]
+    pub fn is_p2pkh(&self) -> bool {
+        self.0.len() == 25 &&
+        self.0[0] == opcodes::All::OP_DUP as u8 &&
+        self.0[1] == opcodes::All::OP_HASH160 as u8 &&
+        self.0[2] == opcodes::All::OP_PUSHBYTES_20 as u8 &&
+        self.0[23] == opcodes::All::OP_EQUALVERIFY as u8 &&
+        self.0[24] == opcodes::All::OP_CHECKSIG as u8
+    }
+
     /// Whether a script can be proven to have no satisfying input
     pub fn is_provably_unspendable(&self) -> bool {
         !self.0.is_empty() && (opcodes::All::from(self.0[0]).classify() == opcodes::Class::ReturnOp ||
@@ -614,5 +625,17 @@ mod test {
         assert_eq!(format!("{}", hex_script!("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")),
                    "Script(OP_0 OP_PUSHBYTES_71 304402202457e78cc1b7f50d0543863c27de75d07982bde8359b9e3316adec0aec165f2f02200203fd331c4e4a4a02f48cf1c291e2c0d6b2f7078a784b5b3649fca41f8794d401 OP_0 OP_PUSHDATA1 552103244e602b46755f24327142a0517288cebd159eccb6ccf41ea6edf1f601e9af952103bbbacc302d19d29dbfa62d23f37944ae19853cf260c745c2bea739c95328fcb721039227e83246bd51140fe93538b2301c9048be82ef2fb3c7fc5d78426ed6f609ad210229bf310c379b90033e2ecb07f77ecf9b8d59acb623ab7be25a0caed539e2e6472103703e2ed676936f10b3ce9149fa2d4a32060fb86fa9a70a4efe3f21d7ab90611921031e9b7c6022400a6bb0424bbcde14cff6c016b91ee3803926f3440abf5c146d05210334667f975f55a8455d515a2ef1c94fdfa3315f12319a14515d2a13d82831f62f57ae)");
     }
+
+    #[test]
+    fn script_p2sh_p2p2k_template() {
+        // random outputs I picked out of the mempool
+        assert!(hex_script!("76a91402306a7c23f3e8010de41e9e591348bb83f11daa88ac").is_p2pkh());
+        assert!(!hex_script!("76a91402306a7c23f3e8010de41e9e591348bb83f11daa88ac").is_p2sh());
+        assert!(!hex_script!("76a91402306a7c23f3e8010de41e9e591348bb83f11daa88ad").is_p2pkh());
+        assert!(!hex_script!("").is_p2pkh());
+        assert!(hex_script!("a914acc91e6fef5c7f24e5c8b3f11a664aa8f1352ffd87").is_p2sh());
+        assert!(!hex_script!("a914acc91e6fef5c7f24e5c8b3f11a664aa8f1352ffd87").is_p2pkh());
+        assert!(!hex_script!("a314acc91e6fef5c7f24e5c8b3f11a664aa8f1352ffd87").is_p2sh());
+    }
 }