First step in adding encryption:

client/src/session_manager.rs

@@ -178,6 +178,7 @@ impl SessionManager {
             challenge_req: None,
             node_id: node_id.into_array().to_vec(),
             public_key: public_key.bytes().to_vec(),
+            supported_encryptions: vec![],
         };
         let response = tmp_session
             .request::<proto::response::Session>(

client/src/session_start.rs

@@ -244,6 +244,7 @@ impl StartingSessions {
                     .map_err(|e| InternalError::Generic(e.to_string()))?,
                 challenge_req: None,
                 public_key: self.layer.config.public_key().await?.bytes().to_vec(),
+                supported_encryptions: vec![],
             };
 
             tmp_session

crates/core/src/challenge.rs

@@ -164,6 +164,7 @@ pub fn prepare_challenge_request() -> (proto::request::Session, [u8; CHALLENGE_S
         public_key: vec![],
         challenge_req: Some(challenge),
         challenge_resp: vec![],
+        supported_encryptions: vec![],
     };
     (request, raw_challenge)
 }
@@ -174,6 +175,7 @@ pub fn prepare_challenge_response() -> (proto::response::Session, [u8; CHALLENGE
         public_key: vec![],
         challenge_req: Some(challenge),
         challenge_resp: vec![],
+        supported_encryptions: vec![],
     };
     (response, raw_challenge)
 }

crates/core/src/session.rs

@@ -32,6 +32,7 @@ pub struct NodeInfo {
 
     /// Endpoints registered by Node.
     pub endpoints: Vec<Endpoint>,
+    pub supported_encryptions: Vec<String>,
 }
 
 #[derive(Clone)]

crates/proto/protobuf/ya_relay.proto

@@ -55,7 +55,8 @@ message Packet {
     message Forward {
         bytes session_id = 1;
         uint32 slot = 2; // either sender or receiver slot id
-        bytes payload = 3;
+        uint16 flags = 3;
+        bytes payload = 4;
     }
 */
 
@@ -99,6 +100,7 @@ message Request {
         bytes public_key = 3;
         ChallengeRequest challenge_req = 4;
         bytes challenge_resp = 5;
+        repeated string supported_encryptions = 6;
     }
 
     message Register {
@@ -153,6 +155,7 @@ message Response {
         bytes public_key = 3;
         ChallengeRequest challenge_req = 4;
         bytes challenge_resp = 5;
+        repeated string supported_encryptions = 6;
     }
 
     /* Registered endpoints */
@@ -168,6 +171,7 @@ message Response {
         repeated Endpoint endpoints = 4;
         uint32 seen_ts = 5;
         uint32 slot = 6;
+        repeated string supported_encryptions = 7;
     }
 
     /* Neighbourhood */

crates/proto/src/codec/datagram.rs

@@ -74,6 +74,7 @@ mod tests {
             node_id: vec![],
             public_key: vec![],
             challenge_req: None,
+            supported_encryptions: vec![],
         })
     }
 
@@ -87,6 +88,7 @@ mod tests {
                     node_id: vec![0x0c, 0x00, 0x0f, 0x0f, 0x0e, 0x0e],
                     public_key: vec![0x05, 0x0e, 0x0c],
                     challenge_req: None,
+                    supported_encryptions: vec![],
                 },
             )
             .into(),
@@ -97,6 +99,7 @@ mod tests {
                     node_id: vec![0x0c, 0x00, 0x0f, 0x0f, 0x0e, 0x0e],
                     public_key: vec![0x05, 0x0e, 0x0c],
                     challenge_req: None,
+                    supported_encryptions: vec![],
                 },
             )
             .into(),

crates/proto/src/codec/stream.rs

@@ -343,6 +343,7 @@ mod tests {
                     node_id: vec![0x0c, 0x00, 0x0f, 0x0f, 0x0e, 0x0e],
                     public_key: vec![0x05, 0x0e, 0x0c],
                     challenge_req: None,
+                    supported_encryptions: vec![],
                 },
             )
             .into(),
@@ -408,6 +409,7 @@ mod tests {
                         node_id: vec![],
                         public_key: vec![],
                         challenge_req: None,
+                        supported_encryptions: vec![],
                     })),
                 })),
             }),

crates/proto/src/proto.rs

@@ -19,6 +19,7 @@ pub const FORWARD_TAG: u32 = 1;
 pub const SESSION_ID_SIZE: usize = 16;
 pub const KEY_SIZE: usize = 1;
 pub const UNRELIABLE_FLAG: u16 = 0x01;
+pub const ENCRYPTED_FLAG: u16 = 0x02;
 
 static REQUEST_ID: AtomicU64 = AtomicU64::new(0);
 

server/src/server.rs

@@ -656,6 +656,7 @@ impl Server {
                     public_key: session.public_key,
                     slot: u32::MAX,
                     endpoints: vec![],
+                    supported_encryptions: vec![],
                 };
 
                 let node = NodeSession {
@@ -962,5 +963,6 @@ pub fn to_node_response(node_info: NodeSession, public_key: bool) -> proto::resp
             .collect(),
         seen_ts: node_info.last_seen.timestamp() as u32,
         slot: node_info.info.slot,
+        supported_encryptions: node_info.info.supported_encryptions,
     }
 }