Migrate to Crypto::PublicKey32 and PrivateKey32

Cargo.lock

@@ -218,6 +218,7 @@ version = "0.0.1"
 dependencies = [
  "blake2",
  "chacha20poly1305",
+ "crypto",
  "hkdf",
  "rand",
  "rand_core",

conversations/src/crypto.rs

@@ -4,6 +4,7 @@ use prost::bytes::Bytes;
 
 pub use crypto::{PrivateKey32, PublicKey32};
 
+// TODO: (P4) Make handing of Keys in Prost easier
 pub trait CopyBytes {
     fn copy_to_bytes(&self) -> Bytes;
 }

crypto/src/keys.rs

@@ -1,24 +1,15 @@
 use generic_array::{GenericArray, typenum::U32};
 use rand_core::{CryptoRng, OsRng, RngCore};
-use std::{fmt::Debug, ops::Deref};
+use std::{
+    fmt::Debug,
+    ops::{Deref, DerefMut},
+};
 use x25519_dalek;
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct PublicKey32(x25519_dalek::PublicKey);
 
-impl From<x25519_dalek::PublicKey> for PublicKey32 {
-    fn from(value: x25519_dalek::PublicKey) -> Self {
-        Self(value)
-    }
-}
-
-impl From<&x25519_dalek::StaticSecret> for PublicKey32 {
-    fn from(value: &x25519_dalek::StaticSecret) -> Self {
-        Self(x25519_dalek::PublicKey::from(value))
-    }
-}
-
 impl From<&PrivateKey32> for PublicKey32 {
     fn from(value: &PrivateKey32) -> Self {
         Self(x25519_dalek::PublicKey::from(&value.0))
@@ -38,6 +29,12 @@ impl Deref for PublicKey32 {
     }
 }
 
+impl DerefMut for PublicKey32 {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
 impl AsRef<[u8]> for PublicKey32 {
     fn as_ref(&self) -> &[u8] {
         self.0.as_ref()
@@ -58,6 +55,12 @@ impl PrivateKey32 {
     }
 }
 
+impl From<[u8; 32]> for PrivateKey32 {
+    fn from(value: [u8; 32]) -> Self {
+        Self(x25519_dalek::StaticSecret::from(value))
+    }
+}
+
 impl Deref for PrivateKey32 {
     type Target = x25519_dalek::StaticSecret;
     fn deref(&self) -> &Self::Target {

double-ratchets/Cargo.toml

@@ -11,8 +11,8 @@ name = "generate-headers"
 required-features = ["headers"]
 
 [dependencies]
-x25519-dalek = { version="2.0.1", features=["static_secrets"] }
 chacha20poly1305 = "0.10.1"
+crypto = { path = "../crypto" }
 rand_core = "0.6.4"
 rand = "0.8.5"
 hkdf = "0.12.4"

double-ratchets/src/ffi/doubleratchet.rs

@@ -1,5 +1,5 @@
+use crypto::PublicKey32;
 use safer_ffi::prelude::*;
-use x25519_dalek::PublicKey;
 
 use crate::{
     Header, RatchetState,
@@ -22,7 +22,7 @@ fn double_ratchet_init_sender(
     shared_secret: [u8; 32],
     remote_pub: [u8; 32],
 ) -> repr_c::Box<FFIRatchetState> {
-    let state = RatchetState::init_sender(shared_secret, PublicKey::from(remote_pub));
+    let state = RatchetState::init_sender(shared_secret, PublicKey32::from(remote_pub));
     Box::new(FFIRatchetState(state)).into()
 }
 

double-ratchets/src/keypair.rs

@@ -1,27 +1,27 @@
+use crypto::{PrivateKey32, PublicKey32};
 use rand_core::OsRng;
-use x25519_dalek::{PublicKey, StaticSecret};
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
 use crate::types::SharedSecret;
 
 #[derive(Clone, Zeroize, ZeroizeOnDrop)]
 pub struct InstallationKeyPair {
-    secret: StaticSecret,
-    public: PublicKey,
+    secret: PrivateKey32,
+    public: PublicKey32,
 }
 
 impl InstallationKeyPair {
     pub fn generate() -> Self {
-        let secret = StaticSecret::random_from_rng(OsRng);
-        let public = PublicKey::from(&secret);
+        let secret = PrivateKey32::random_from_rng(OsRng);
+        let public = PublicKey32::from(&secret);
         Self { secret, public }
     }
 
-    pub fn dh(&self, their_public: &PublicKey) -> SharedSecret {
+    pub fn dh(&self, their_public: &PublicKey32) -> SharedSecret {
         self.secret.diffie_hellman(their_public).to_bytes()
     }
 
-    pub fn public(&self) -> &PublicKey {
+    pub fn public(&self) -> &PublicKey32 {
         &self.public
     }
 
@@ -32,8 +32,8 @@ impl InstallationKeyPair {
 
     /// Import the secret key from raw bytes.
     pub fn from_secret_bytes(bytes: [u8; 32]) -> Self {
-        let secret = StaticSecret::from(bytes);
-        let public = PublicKey::from(&secret);
+        let secret = PrivateKey32::from(bytes);
+        let public = PublicKey32::from(&secret);
         Self { secret, public }
     }
 }

double-ratchets/src/state.rs

@@ -1,7 +1,7 @@
 use std::{collections::HashMap, marker::PhantomData};
 
+use crypto::PublicKey32;
 use serde::{Deserialize, Deserializer, Serialize, Serializer, de::Error as DeError};
-use x25519_dalek::PublicKey;
 use zeroize::{Zeroize, Zeroizing};
 
 use crate::{
@@ -29,13 +29,13 @@ pub struct RatchetState<D: HkdfInfo = DefaultDomain> {
     pub receiving_chain: Option<ChainKey>,
 
     pub dh_self: InstallationKeyPair,
-    pub dh_remote: Option<PublicKey>,
+    pub dh_remote: Option<PublicKey32>,
 
     pub msg_send: u32,
     pub msg_recv: u32,
     pub prev_chain_len: u32,
 
-    pub skipped_keys: HashMap<(PublicKey, u32), MessageKey>,
+    pub skipped_keys: HashMap<(PublicKey32, u32), MessageKey>,
 
     pub(crate) _domain: PhantomData<D>,
 }
@@ -144,7 +144,7 @@ impl<D: HkdfInfo> RatchetState<D> {
         let dh_self = InstallationKeyPair::from_secret_bytes(dh_self_bytes);
         dh_self_bytes.zeroize();
 
-        let dh_remote = reader.read_option()?.map(PublicKey::from);
+        let dh_remote = reader.read_option()?.map(PublicKey32::from);
 
         let msg_send = reader.read_u32()?;
         let msg_recv = reader.read_u32()?;
@@ -153,7 +153,7 @@ impl<D: HkdfInfo> RatchetState<D> {
         let skipped_count = reader.read_u32()? as usize;
         let mut skipped_keys = HashMap::with_capacity(skipped_count);
         for _ in 0..skipped_count {
-            let pk = PublicKey::from(reader.read_array::<32>()?);
+            let pk = PublicKey32::from(reader.read_array::<32>()?);
             let msg_num = reader.read_u32()?;
             let mk: MessageKey = reader.read_array()?;
             skipped_keys.insert((pk, msg_num), mk);
@@ -198,7 +198,7 @@ impl<'de, D: HkdfInfo> Deserialize<'de> for RatchetState<D> {
 /// Public header attached to every encrypted message (unencrypted but authenticated).
 #[derive(Clone, Debug)]
 pub struct Header {
-    pub dh_pub: PublicKey,
+    pub dh_pub: PublicKey32,
     pub msg_num: u32,
     pub prev_chain_len: u32,
 }
@@ -233,7 +233,7 @@ impl<D: HkdfInfo> RatchetState<D> {
     /// # Returns
     ///
     /// A new `RatchetState` ready to send the first message.
-    pub fn init_sender(shared_secret: SharedSecret, remote_pub: PublicKey) -> Self {
+    pub fn init_sender(shared_secret: SharedSecret, remote_pub: PublicKey32) -> Self {
         let dh_self = InstallationKeyPair::generate();
 
         // Initial DH
@@ -296,7 +296,7 @@ impl<D: HkdfInfo> RatchetState<D> {
     /// # Arguments
     ///
     /// * `remote_pub` - The new DH public key from the sender.
-    pub fn dh_ratchet_receive(&mut self, remote_pub: PublicKey) {
+    pub fn dh_ratchet_receive(&mut self, remote_pub: PublicKey32) {
         let dh_out = self.dh_self.dh(&remote_pub);
         let (new_root, recv_chain) = kdf_root::<D>(&self.root_key, &dh_out);
 
@@ -605,7 +605,7 @@ mod tests {
         // Tamper with header (change DH pub byte)
         let mut tampered_pub_bytes = header.dh_pub.to_bytes();
         tampered_pub_bytes[0] ^= 0xff;
-        header.dh_pub = PublicKey::from(tampered_pub_bytes);
+        header.dh_pub = PublicKey32::from(tampered_pub_bytes);
 
         let result = bob.decrypt_message(&ct, header);
         assert!(result.is_err());

double-ratchets/src/storage/session.rs

@@ -1,4 +1,4 @@
-use x25519_dalek::PublicKey;
+use crypto::PublicKey32;
 
 use crate::{
     InstallationKeyPair,
@@ -82,7 +82,7 @@ impl<'a, D: HkdfInfo + Clone> RatchetSession<'a, D> {
         storage: &'a mut SqliteStorage,
         conversation_id: impl Into<String>,
         shared_secret: SharedSecret,
-        remote_pub: PublicKey,
+        remote_pub: PublicKey32,
     ) -> Result<Self, StorageError> {
         let state = RatchetState::<D>::init_sender(shared_secret, remote_pub);
         Self::create(storage, conversation_id, state)

double-ratchets/src/storage/types.rs

@@ -3,8 +3,8 @@ use crate::{
     state::{RatchetState, SkippedKey},
     types::MessageKey,
 };
+use crypto::PublicKey32;
 use thiserror::Error;
-use x25519_dalek::PublicKey;
 
 #[derive(Debug, Error)]
 pub enum StorageError {
@@ -58,11 +58,16 @@ impl RatchetStateRecord {
         use std::marker::PhantomData;
 
         let dh_self = InstallationKeyPair::from_secret_bytes(self.dh_self_secret);
-        let dh_remote = self.dh_remote.map(PublicKey::from);
+        let dh_remote = self.dh_remote.map(PublicKey32::from);
 
-        let skipped: HashMap<(PublicKey, u32), MessageKey> = skipped_keys
+        let skipped: HashMap<(PublicKey32, u32), MessageKey> = skipped_keys
             .into_iter()
-            .map(|sk| ((PublicKey::from(sk.public_key), sk.msg_num), sk.message_key))
+            .map(|sk| {
+                (
+                    (PublicKey32::from(sk.public_key), sk.msg_num),
+                    sk.message_key,
+                )
+            })
             .collect();
 
         RatchetState {