From 72ddc7d7a1320b2f3666d0bf0b6993cc6b2ff5c5 Mon Sep 17 00:00:00 2001
From: Deirdre Connolly <deirdre@zfnd.org>
Date: Mon, 2 Mar 2020 18:24:31 -0500
Subject: [PATCH] Add AddressPayloadHash type

Includes From impls for Script, secp256k1::PublicKey
---
 Cargo.lock                          | 12 ++++++
 zebra-chain/Cargo.toml              |  1 +
 zebra-chain/src/addresses.rs        | 58 +++++++++++++++++++++++++++++
 zebra-chain/src/keys/transparent.rs |  4 +-
 4 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5a451b5c..36306cf7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1364,6 +1364,17 @@ dependencies = [
  "winapi 0.3.8",
 ]
 
+[[package]]
+name = "ripemd160"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ad5112e0dbbb87577bfbc56c42450235e3012ce336e29c5befd7807bd626da4a"
+dependencies = [
+ "block-buffer",
+ "digest",
+ "opaque-debug",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.16"
@@ -2034,6 +2045,7 @@ dependencies = [
  "proptest",
  "proptest-derive",
  "redjubjub",
+ "ripemd160",
  "secp256k1",
  "sha2",
  "thiserror",
diff --git a/zebra-chain/Cargo.toml b/zebra-chain/Cargo.toml
index bb7cef76..907aab35 100644
--- a/zebra-chain/Cargo.toml
+++ b/zebra-chain/Cargo.toml
@@ -13,6 +13,7 @@ chrono = "0.4"
 futures = "0.3"
 hex = "0.4"
 lazy_static = "1.4.0"
+ripemd160 = "0.8.0"
 secp256k1 = "0.17.2"
 sha2 = "0.8"
 thiserror = "1"
diff --git a/zebra-chain/src/addresses.rs b/zebra-chain/src/addresses.rs
index ac30a0d7..8731fb80 100644
--- a/zebra-chain/src/addresses.rs
+++ b/zebra-chain/src/addresses.rs
@@ -1,6 +1,64 @@
 //! Address types.
 
+use secp256k1::PublicKey;
+
+use crate::serialization::{
+    ReadZcashExt, SerializationError, WriteZcashExt, ZcashDeserialize, ZcashSerialize,
+};
+
+use crate::types::Script;
+
+/// A hash of a redeem script, as used in transparent
+/// pay-to-script-hash addresses.
+///
+/// https://en.bitcoin.it/Base58Check_encoding#Encoding_a_Bitcoin_address
+#[derive(Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(test, derive(Arbitrary))]
+struct AddressPayloadHash(pub [u8; 20]);
+
+impl From<Script> for AddressPayloadHash {
+    fn from(script: Script) -> Self {
+        use ripemd160::Ripdemd160;
+        use sha2::Sha256;
+
+        let hash = Ripdemd160::digest(Sha256::digest(&script.0[..]));
+
+        Self(hash)
+    }
+}
+
+impl From<PublicKey> for AddressPayloadHash {
+    fn from(publickey: PublicKey) -> Self {
+        use ripemd160::Ripdemd160;
+        use sha2::Sha256;
+
+        let hash = Ripdemd160::digest(Sha256::digest(&publickey.0[..]));
+
+        Self(hash)
+    }
+}
+
+impl fmt::Debug for AddressPayloadHash {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("AddressPayloadHash")
+            .field(&hex::encode(&self.0))
+            .finish()
+    }
+}
+
 pub enum TransparentAddress {
     PayToScriptHash,
     PayToPublicKeyHash,
 }
+
+impl ZcashSerialize for Transaction {
+    fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
+        unimplemented!();
+    }
+}
+
+impl ZcashDeserialize for Transaction {
+    fn zcash_deserialize<R: io::Read>(mut reader: R) -> Result<Self, SerializationError> {
+        unimplemented!();
+    }
+}
diff --git a/zebra-chain/src/keys/transparent.rs b/zebra-chain/src/keys/transparent.rs
index 4b2c2257..68a49b18 100644
--- a/zebra-chain/src/keys/transparent.rs
+++ b/zebra-chain/src/keys/transparent.rs
@@ -2,9 +2,7 @@ use std::io;
 
 use secp256k1::PublicKey;
 
-use crate::serialization::{
-    ReadZcashExt, SerializationError, WriteZcashExt, ZcashDeserialize, ZcashSerialize,
-};
+use crate::serialization::{SerializationError, ZcashDeserialize, ZcashSerialize};
 
 impl ZcashSerialize for PublicKey {
     fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {