[WIP][Session] Adding the Relay type (#53)

Scaffolding and customizing the first version of the `Relay` type.

go.mod

@@ -17,7 +17,6 @@ require (
 	github.com/spf13/cobra v1.7.0
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.8.4
-	google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1
 	google.golang.org/grpc v1.56.1
 	gopkg.in/yaml.v2 v2.4.0
 )
@@ -259,6 +258,7 @@ require (
 	gonum.org/v1/gonum v0.11.0 // indirect
 	google.golang.org/api v0.122.0 // indirect
 	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 // indirect
 	google.golang.org/protobuf v1.31.0 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

proto/pocket/service/relay.proto

@@ -0,0 +1,106 @@
+syntax = "proto3";
+package pocket.service;
+
+option go_package = "pocket/x/service/types";
+
+import "cosmos_proto/cosmos.proto";
+// TODO(@Olshansk): Uncomment the line below once the `service.proto` is added.
+// import "pocket/service/service.proto";
+import "pocket/application/application.proto";
+import "pocket/supplier/supplier.proto";
+
+// Relay contains both the RelayRequest (signed by the Application) and the RelayResponse (signed by the Supplier).
+// The serialized tuple is inserted into the SMST leaves as values in the Claim/Proof lifecycle.
+message Relay {
+    RelayRequest req = 1;
+    RelayResponse res = 2;
+}
+
+// RelayRequestMetadata contains the metadata for a RelayRequest.
+message RelayRequestMetadata {
+    // TODO(@Olshansk): Uncomment the line below once the `service.proto` is added.
+    // session.SessionHeader session_header = 1; // Session header associated with the relay.
+    // TODO_COMMENT(@h5law): Add link or more details to how this is related to ring signatures once implemented.
+    bytes signature = 2; // The request signature. This may be the application signature, or any gateway it delegated to.
+}
+
+// RelayRequest holds the request details for a relay.
+message RelayRequest {
+    RelayRequestMetadata meta = 1;
+    oneof payload {
+        JSONRPCRequestPayload json_rpc_payload = 2;
+        RESTRequestPayload rest_payload = 3;
+        // Future possible relay types:
+        // WebSocketsRequestPayload websockets_payload = 4;
+        // GRPCRequestPayload grpc_payload = 5;
+        // GraphQLRequestPayload graphql_payload = 6;
+    }
+}
+
+// JSONRPCRequestPayload contains the payload for a JSON-RPC request.
+// See https://www.jsonrpc.org/specification#request_object for more details.
+message JSONRPCRequestPayload {
+    bytes id = 1; // Identifier established by the Client to create context for the request.
+    string jsonrpc = 2; // Version of JSON-RPC. Must be exactly "2.0".
+    string method = 3; // Method being invoked on the server.
+    map<string, string> parameters = 4; // Parameters for the method. https://www.jsonrpc.org/specification#parameter_structures
+}
+
+// RESTRequestType represents the type of REST request.
+enum RESTRequestType {
+    REST_REQUEST_TYPE_UNKNOWN = 0; // Default uninitialized value.
+    REST_REQUEST_TYPE_GET = 1;
+    REST_REQUEST_TYPE_PUT = 2;
+    REST_REQUEST_TYPE_POST = 3;
+    REST_REQUEST_TYPE_DELETE = 4;
+}
+
+// RESTRequestPayload contains the payload and metadata for a REST request.
+message RESTRequestPayload {
+    RESTRequestType request_type = 1;
+    string http_path = 2; // Path for the REST endpoint.
+    string contents = 3; // Request contents.
+    map<string, string> headers = 4; // Request headers.
+}
+
+// RelayResponse contains the response details for a RelayRequest.
+message RelayResponse {
+    RelayResponseMetadata meta = 1;
+    oneof payload {
+        JSONRPCResponsePayload json_rpc_payload = 2;
+        RESTResponsePayload rest_payload = 3;
+        // Future possible relay types:
+        // WebSocketsResponsePayload websockets_payload = 4;
+        // GRPCResponsePayload grpc_payload = 5;
+        // GraphQLResponsePayload graphql_payload = 6;
+    }
+}
+
+// RelayResponseMetadata contains the metadata for a RelayResponse.
+message RelayResponseMetadata {
+    // TODO(@Olshansk): Uncomment the line below once the `service.proto` is added.
+    // session.SessionHeader session_header = 1; // Session header associated with the relay.
+    bytes supplier_signature = 2; // Signature of the supplier on the response.
+}
+
+// JSONRPCResponsePayload contains the response details for a JSON-RPC relay.
+// See www.jsonrpc.org/specification for more details.
+message JSONRPCResponsePayload {
+    bytes id = 1; // Identifier established by the Client to link the response back to the request.
+    string jsonrpc = 2; // Version of JSON-RPC. Must be exactly "2.0".
+    bytes result = 3; // Response result payload.
+    JSONRPCResponseError error = 4; // Error message, if any. Can be nil.
+}
+
+message JSONRPCResponseError {
+    int32 code = 1; // Error code.
+    string message  = 2; // Error message.
+    bytes data = 3; // Error data.
+}
+
+// RESTResponsePayload contains the response details for a REST relay.
+message RESTResponsePayload {
+    uint32 status_code = 1; // Response status code.
+    string err = 2; // Error message, if any.
+    bytes payload = 3; // Response payload.
+}