add validation of orchard anchor

librustzcash-wrapper/src/lib.rs

@@ -1563,12 +1563,20 @@ pub extern "C" fn rust_wrapper_read_orchard_tree_anchor(
     out: *mut u8,
     out_len: &mut usize
     ){
-    let tree_in: Hfrontier = marshall_from_haskell_var(tree, tree_len, RW);
-    let leaf = MerkleHashOrchard::from_bytes(&to_array(tree_in.leaf.bytes)).unwrap();
-    let comm_tree: Frontier<MerkleHashOrchard,32> = Frontier::from_parts(Position::from(tree_in.position), leaf, tree_in.ommers.iter().map(|x| MerkleHashOrchard::from_bytes(&to_array(x.bytes.clone())).unwrap() ).collect()).unwrap();
-    let root = comm_tree.root();
+    let tree_in: Vec<u8> = marshall_from_haskell_var(tree, tree_len, RW);
+    let tree_reader = Cursor::new(tree_in);
+    let comm_tree = read_commitment_tree(tree_reader);
+    match comm_tree {
+        Ok::<CommitmentTree<MerkleHashOrchard, 32>, _>(c1) => {
+            let root = c1.root();
             let h = Hhex { bytes: root.to_bytes().to_vec() };
             marshall_to_haskell_var(&h, out, out_len, RW);
+        },
+        Err(_) => {
+            let h0 = Hhex { bytes: vec![0] };
+            marshall_to_haskell_var(&h0, out, out_len, RW);
+        }
+    }
 }
 
 #[no_mangle]

src/C/Zcash.chs

@@ -263,7 +263,7 @@ import ZcashHaskell.Types
 #}
 
 {# fun unsafe rust_wrapper_read_orchard_tree_anchor as rustWrapperReadOrchardTreeAnchor
-     { toBorshVar* `OrchardFrontier'&
+     { toBorshVar* `BS.ByteString'&
      , getVarBuffer `Buffer HexString'&
      }
   -> `()'

src/ZcashHaskell/Orchard.hs

@@ -212,9 +212,10 @@ getOrchardFrontier tree =
       withPureBorshVarBuffer $
       rustWrapperReadOrchardFrontier $ toBytes $ orchTree tree
 
-getOrchardTreeAnchor :: OrchardFrontier -> HexString
+getOrchardTreeAnchor :: OrchardCommitmentTree -> HexString
 getOrchardTreeAnchor tree =
-  withPureBorshVarBuffer $ rustWrapperReadOrchardTreeAnchor tree
+  withPureBorshVarBuffer $
+  rustWrapperReadOrchardTreeAnchor $ toBytes $ orchTree tree
 
 getOrchardWitnessAnchor :: OrchardWitness -> HexString
 getOrchardWitnessAnchor wit =