Add AsRef<[u8]> and Into<[u8; N]> for ECPublicKey (#33)

* Add AsRef<[u8]> and Into<[u8; N]> for ECPublicKey

* add as_ref/to_bytes to ecc::PublicKey

* remove privatekey internal access, add Eq to CxError

Author: ryankurte

src/ecc.rs

@@ -25,6 +25,7 @@ pub enum CurvesId {
     Invalid,
 }
 
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub enum CxError {
     Carry,
     Locked,
@@ -165,6 +166,7 @@ pub struct ECPublicKey<const S: usize, const TY: char> {
     pubkey: [u8; S],
 }
 
+/// Create a default (empty/invalid) private key object
 impl<const N: usize, const TY: char> Default for ECPrivateKey<N, TY> {
     fn default() -> ECPrivateKey<N, TY> {
         ECPrivateKey {
@@ -347,6 +349,20 @@ impl<const P: usize, const TY: char> ECPublicKey<P, TY> {
     }
 }
 
+/// Access public key value by reference
+impl<const P: usize, const TY: char> AsRef<[u8]> for ECPublicKey<P, TY> {
+    fn as_ref(&self) -> &[u8] {
+        &self.pubkey
+    }
+}
+
+/// Access public key value as array
+impl<const P: usize, const TY: char> From<ECPublicKey<P, TY>> for [u8; P] {
+    fn from(p: ECPublicKey<P, TY>) -> Self {
+        p.pubkey
+    }
+}
+
 /// Specific signature verification for Weierstrass curves, which
 /// all use ECDSA.
 impl<const P: usize> ECPublicKey<P, 'W'> {