Adds conversion impl from HashType for SighashType

Author: arya2

zebra-chain/src/primitives/zcash_primitives.rs

@@ -295,7 +295,7 @@ pub(crate) fn sighash(
             unlock_script = zcash_primitives::legacy::Script(script_code);
             zp_tx::sighash::SignableInput::Transparent(
                 zcash_transparent::sighash::SignableInput::from_parts(
-                    hash_type.bits() as _,
+                    hash_type.try_into().expect("hash type should be ALL"),
                     input_index,
                     &unlock_script,
                     &lock_script,

zebra-chain/src/transaction/sighash.rs

@@ -1,5 +1,7 @@
 //! Signature hashes for Zcash transactions
 
+use zcash_transparent::sighash::SighashType;
+
 use super::Transaction;
 
 use crate::parameters::NetworkUpgrade;
@@ -19,6 +21,29 @@ bitflags::bitflags! {
         const SINGLE = Self::ALL.bits() | Self::NONE.bits();
         /// Anyone can add inputs to this transaction
         const ANYONECANPAY = 0b1000_0000;
+
+        /// Sign all the outputs and Anyone can add inputs to this transaction
+        const ALL_ANYONECANPAY = Self::ALL.bits() | Self::ANYONECANPAY.bits();
+        /// Sign none of the outputs and Anyone can add inputs to this transaction
+        const NONE_ANYONECANPAY = Self::NONE.bits() | Self::ANYONECANPAY.bits();
+        /// Sign one of the outputs and Anyone can add inputs to this transaction
+        const SINGLE_ANYONECANPAY = Self::SINGLE.bits() | Self::ANYONECANPAY.bits();
+    }
+}
+
+impl TryFrom<HashType> for SighashType {
+    type Error = ();
+
+    fn try_from(hash_type: HashType) -> Result<Self, Self::Error> {
+        Ok(match hash_type {
+            HashType::ALL => Self::ALL,
+            HashType::NONE => Self::NONE,
+            HashType::SINGLE => Self::SINGLE,
+            HashType::ALL_ANYONECANPAY => Self::ALL_ANYONECANPAY,
+            HashType::NONE_ANYONECANPAY => Self::NONE_ANYONECANPAY,
+            HashType::SINGLE_ANYONECANPAY => Self::SINGLE_ANYONECANPAY,
+            _other => return Err(()),
+        })
     }
 }