Merge pull request #119 from zcash/anchor-serialization

Anchor serialization APIs

src/tree.rs

@@ -7,12 +7,12 @@ use crate::{
 };
 use pasta_curves::pallas;
 
-use ff::{Field, PrimeFieldBits};
+use ff::{Field, PrimeField, PrimeFieldBits};
 use rand::RngCore;
 use std::iter;
 
 /// The root of an Orchard commitment tree.
-#[derive(Eq, PartialEq, Clone, Debug)]
+#[derive(Eq, PartialEq, Clone, Copy, Debug)]
 pub struct Anchor(pallas::Base);
 
 impl From<pallas::Base> for Anchor {
@@ -21,6 +21,18 @@ impl From<pallas::Base> for Anchor {
     }
 }
 
+impl Anchor {
+    /// Parses an Orchard anchor from a byte encoding.
+    pub fn from_bytes(bytes: [u8; 32]) -> Option<Anchor> {
+        pallas::Base::from_repr(bytes).map(Anchor)
+    }
+
+    /// Returns the byte encoding of this anchor.
+    pub fn to_bytes(self) -> [u8; 32] {
+        self.0.to_repr()
+    }
+}
+
 #[derive(Debug)]
 pub struct MerklePath {
     position: u32,