Made ring optional

src/kdf_chain.rs

@@ -1,5 +1,11 @@
 use hmac::{Hmac, Mac, NewMac};
+
+#[cfg(feature = "ring")]
 use ring_compat::digest::Sha512;
+
+#[cfg(feature = "default")]
+use sha2::Sha512;
+
 use core::convert::TryInto;
 
 #[cfg(test)]

src/kdf_root.rs

@@ -1,6 +1,12 @@
 use x25519_dalek::SharedSecret;
 use hkdf::Hkdf;
+
+#[cfg(feature = "ring")]
 use ring_compat::digest::Sha512;
+
+#[cfg(feature = "default")]
+use sha2::Sha512;
+
 use core::convert::TryInto;
 
 #[cfg(test)]

src/lib.rs

@@ -1,6 +1,5 @@
 #![no_std]
 #![allow(stable_features)]
-#![feature(alloc)]
 
 extern crate alloc;
 
@@ -8,5 +7,9 @@ mod aead;
 mod dh;
 mod kdf_root;
 mod kdf_chain;
-mod header;
+
+/// Providing essential functions
 pub mod ratchet;
+
+/// Message Header
+pub mod header;

src/ratchet.rs

@@ -9,6 +9,7 @@ use crate::aead::{encrypt, decrypt};
 
 const MAX_SKIP: usize = 100;
 
+/// Object Representing Ratchet
 pub struct Ratchet {
     dhs: DhKeyPair,
     dhr: Option<PublicKey>,