Define main types for the library.

src/lib.rs

@@ -10,6 +10,9 @@ mod secret_key;
 mod signature;
 
 pub use error::Error;
+pub use public_key::{PublicKey, PublicKeyBytes};
+pub use secret_key::{SecretKey, SecretKeyBytes};
+pub use signature::Signature;
 
 #[cfg(test)]
 mod tests {

src/public_key.rs

@@ -0,0 +1,41 @@
+use std::convert::TryFrom;
+
+use crate::Error;
+
+/// A refinement type indicating that the inner `[u8; 32]` represents an
+/// encoding of a RedJubJub public key.
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct PublicKeyBytes(pub [u8; 32]);
+
+impl From<[u8; 32]> for PublicKeyBytes {
+    fn from(raw: [u8; 32]) -> PublicKeyBytes {
+        PublicKeyBytes(raw)
+    }
+}
+
+impl From<PublicKeyBytes> for [u8; 32] {
+    fn from(refined: PublicKeyBytes) -> [u8; 32] {
+        refined.0
+    }
+}
+
+/// A RedJubJub public key.
+// XXX PartialEq, Eq?
+#[derive(Copy, Clone, Debug)]
+pub struct PublicKey {
+    // fields
+}
+
+impl From<PublicKey> for PublicKeyBytes {
+    fn from(pk: PublicKey) -> PublicKeyBytes {
+        unimplemented!();
+    }
+}
+
+impl TryFrom<PublicKeyBytes> for PublicKey {
+    type Error = Error;
+
+    fn try_from(bytes: PublicKeyBytes) -> Result<Self, Self::Error> {
+        unimplemented!();
+    }
+}

src/secret_key.rs

@@ -0,0 +1,41 @@
+use std::convert::TryFrom;
+
+use crate::Error;
+
+/// A refinement type indicating that the inner `[u8; 32]` represents an
+/// encoding of a RedJubJub secret key.
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct SecretKeyBytes(pub [u8; 32]);
+
+impl From<[u8; 32]> for SecretKeyBytes {
+    fn from(raw: [u8; 32]) -> SecretKeyBytes {
+        SecretKeyBytes(raw)
+    }
+}
+
+impl From<SecretKeyBytes> for [u8; 32] {
+    fn from(refined: SecretKeyBytes) -> [u8; 32] {
+        refined.0
+    }
+}
+
+/// A RedJubJub secret key.
+// XXX PartialEq, Eq?
+#[derive(Copy, Clone, Debug)]
+pub struct SecretKey {
+    // fields
+}
+
+impl From<SecretKey> for SecretKeyBytes {
+    fn from(pk: SecretKey) -> SecretKeyBytes {
+        unimplemented!();
+    }
+}
+
+impl TryFrom<SecretKeyBytes> for SecretKey {
+    type Error = Error;
+
+    fn try_from(bytes: SecretKeyBytes) -> Result<Self, Self::Error> {
+        unimplemented!();
+    }
+}

src/signature.rs

@@ -0,0 +1,14 @@
+/// A RedJubJub signature.
+pub struct Signature(pub [u8; 64]);
+
+impl From<[u8; 64]> for Signature {
+    fn from(bytes: [u8; 64]) -> Signature {
+        Signature(bytes)
+    }
+}
+
+impl From<Signature> for [u8; 64] {
+    fn from(s: Signature) -> [u8; 64] {
+        s.0
+    }
+}