rpc: add support for protobuf-encoded messages

Adds initial support for the Protobuf-based RPC protocol used by
Tendermint v0.34.

Cargo.toml

@@ -28,9 +28,10 @@ ledger = { version = "0.2", optional = true }
 merlin = "2"
 once_cell = "1.4"
 prost = "0.6"
-prost-derive = "0.6"
 prost-amino = "0.6"
 prost-amino-derive = "0.6"
+prost-derive = "0.6"
+prost-types = "0.6"
 rand_core = { version = "0.5", features = ["std"] }
 rpassword = { version = "5", optional = true }
 serde = { version = "1", features = ["serde_derive"] }

src/connection/secret_connection.rs

@@ -3,7 +3,7 @@
 mod amino_types;
 mod kdf;
 mod nonce;
-mod proto_types;
+pub(crate) mod proto_types;
 mod protocol;
 mod public_key;
 
@@ -36,9 +36,11 @@ use zeroize::Zeroizing;
 /// Size of the MAC tag
 pub const TAG_SIZE: usize = 16;
 
+/// Maximum size of a message
+pub const DATA_MAX_SIZE: usize = 1024;
+
 /// 4 + 1024 == 1028 total frame size
 const DATA_LEN_SIZE: usize = 4;
-const DATA_MAX_SIZE: usize = 1024;
 const TOTAL_FRAME_SIZE: usize = DATA_MAX_SIZE + DATA_LEN_SIZE;
 
 /// Generate a Secret Connection key at the given path

src/connection/secret_connection/proto_types.rs

@@ -1,4 +1,4 @@
-//! Secret Connection Protobuf Types
+//! Secret Connection Protobuf Types (tendermint.p2p.conn)
 //!
 //! Generated from:
 //! <https://github.com/tendermint/tendermint/blob/730e165/proto/tendermint/p2p/conn.proto>

src/connection/secret_connection/protocol.rs

@@ -34,20 +34,20 @@ pub enum Version {
 
 impl Version {
     /// Does this version of Secret Connection use a transcript hash
-    pub(super) fn has_transcript(self) -> bool {
+    pub fn has_transcript(self) -> bool {
         self != Version::Legacy
     }
 
     /// Are messages encoded using Protocol Buffers?
-    pub(super) fn is_protobuf(self) -> bool {
+    pub fn is_protobuf(self) -> bool {
         match self {
             Version::V0_34 => true,
             Version::V0_33 | Version::Legacy => false,
         }
     }
 
     /// Encode the initial handshake message (i.e. first one sent by both peers)
-    pub(super) fn encode_initial_handshake(self, eph_pubkey: &EphemeralPublic) -> Vec<u8> {
+    pub fn encode_initial_handshake(self, eph_pubkey: &EphemeralPublic) -> Vec<u8> {
         if self.is_protobuf() {
             // Equivalent Go implementation:
             // https://github.com/tendermint/tendermint/blob/9e98c74/p2p/conn/secret_connection.go#L307-L312
@@ -72,7 +72,7 @@ impl Version {
     }
 
     /// Decode the initial handshake message
-    pub(super) fn decode_initial_handshake(self, bytes: &[u8]) -> Result<EphemeralPublic, Error> {
+    pub fn decode_initial_handshake(self, bytes: &[u8]) -> Result<EphemeralPublic, Error> {
         let eph_pubkey = if self.is_protobuf() {
             // Equivalent Go implementation:
             // https://github.com/tendermint/tendermint/blob/9e98c74/p2p/conn/secret_connection.go#L315-L323
@@ -111,7 +111,7 @@ impl Version {
     }
 
     /// Encode signature which authenticates the handshake
-    pub(super) fn encode_auth_signature(
+    pub fn encode_auth_signature(
         self,
         pub_key: &ed25519::PublicKey,
         signature: &ed25519::Signature,
@@ -149,7 +149,7 @@ impl Version {
     }
 
     /// Get the length of the auth message response for this protocol version
-    pub(super) fn auth_sig_msg_response_len(self) -> usize {
+    pub fn auth_sig_msg_response_len(self) -> usize {
         if self.is_protobuf() {
             // 32 + 64 + (proto overhead = 1 prefix + 2 fields + 2 lengths + total length)
             103
@@ -160,10 +160,7 @@ impl Version {
     }
 
     /// Decode signature message which authenticates the handshake
-    pub(super) fn decode_auth_signature(
-        self,
-        bytes: &[u8],
-    ) -> Result<proto_types::AuthSigMessage, Error> {
+    pub fn decode_auth_signature(self, bytes: &[u8]) -> Result<proto_types::AuthSigMessage, Error> {
         if self.is_protobuf() {
             // Parse Protobuf-encoded `AuthSigMessage`
             proto_types::AuthSigMessage::decode_length_delimited(bytes).map_err(|e| {

src/error.rs

@@ -185,6 +185,18 @@ impl std::error::Error for Error {
     }
 }
 
+impl From<prost::DecodeError> for Error {
+    fn from(other: prost::DecodeError) -> Self {
+        ErrorKind::ProtocolError.context(other).into()
+    }
+}
+
+impl From<prost::EncodeError> for Error {
+    fn from(other: prost::EncodeError) -> Self {
+        ErrorKind::ProtocolError.context(other).into()
+    }
+}
+
 impl From<prost_amino::DecodeError> for Error {
     fn from(other: prost_amino::DecodeError) -> Self {
         ErrorKind::ProtocolError.context(other).into()

src/lib.rs

@@ -19,6 +19,7 @@ pub mod error;
 pub mod key_utils;
 pub mod keyring;
 pub mod prelude;
+pub mod proto_types;
 pub mod rpc;
 pub mod session;