Feature/nymd client integration (#736)

* Calculating gas fees

* Ability to set custom fees

* Added extra test

* Removed commented code

* Moved all msg types to common contract crate

* Temporarily disabling get_tx method

* Finishing up nymd client API

* Comment fix

* Remaining fee values

* Some cleanup

* Removed needless borrow

* Fixed imports in contract tests

* Moved error types around

* New ValidatorClient

* Experiment with new type of defaults

* Removed dead module

* Dealt with unwrap

* Migrated mixnode to use new validator client

* Migrated gateway to use new validator client

* Mixnode and gateway adjustments

* More exported defaults

* Clients using new validator client

* Fixed mixnode upgrade

* Moved default values to a new crate

* Changed behaviour of validator client features

* Migrated basic functions of validator api

* Updated config + fixed startup

* Fixed wasm client build

* Integration with the explorer api

* Removed tokio dev dependency

* Needless borrow

* Fixex wasm client build

* Fixed tauri client build

* Needless borrows

* Fixed client upgrade print

* Removed redundant comments

* Made note on aggregated verification key into a doc comment

* Removed mixnet contract references from verloc

* Modified default validators structure

* Reformatted validator-api Cargo.toml file

* Removed commented code

* Made the doc comment example a no-run

* Fixed a upgrade print... again

* Adjusted the doc example

* Removed unused import

validator-api/src/network_monitor/monitor/sender.rs

@@ -1,7 +1,6 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0
 
-use crate::config::DEFAULT_VALIDATOR_HOST;
 use crate::network_monitor::monitor::receiver::{GatewayClientUpdate, GatewayClientUpdateSender};
 use coconut_interface::Credential;
 use crypto::asymmetric::identity::{self, PUBLIC_KEY_LENGTH};
@@ -22,7 +21,6 @@ use std::sync::Arc;
 use std::task::Poll;
 use std::time::Duration;
 use tokio::time::Instant;
-use validator_client::validator_api::VALIDATOR_API_PORT;
 
 const TIME_CHUNK_SIZE: Duration = Duration::from_millis(50);
 
@@ -65,6 +63,15 @@ struct FreshGatewayClientData {
     gateways_status_updater: GatewayClientUpdateSender,
     local_identity: Arc<identity::KeyPair>,
     gateway_response_timeout: Duration,
+
+    // I guess in the future this struct will require aggregated verification key and....
+    // ... something for obtaining actual credential
+
+    // TODO:
+    // SECURITY:
+    // since currently we have no double spending protection, just to get things running
+    // we're re-using the same credential for all gateways all the time. THIS IS VERY BAD!!
+    bandwidth_credential: Credential,
 }
 
 pub(crate) struct PacketSender {
@@ -84,6 +91,7 @@ impl PacketSender {
     pub(crate) fn new(
         gateways_status_updater: GatewayClientUpdateSender,
         local_identity: Arc<identity::KeyPair>,
+        bandwidth_credential: Credential,
         gateway_response_timeout: Duration,
         gateway_connection_timeout: Duration,
         max_concurrent_clients: usize,
@@ -95,6 +103,7 @@ impl PacketSender {
                 gateways_status_updater,
                 local_identity,
                 gateway_response_timeout,
+                bandwidth_credential,
             }),
             gateway_connection_timeout,
             max_concurrent_clients,
@@ -114,16 +123,6 @@ impl PacketSender {
         // use old shared keys
         let (message_sender, message_receiver) = mpsc::unbounded();
 
-        let coconut_credential = Credential::init(
-            vec![format!(
-                "http://{}:{}",
-                DEFAULT_VALIDATOR_HOST, VALIDATOR_API_PORT
-            )],
-            identity,
-        )
-        .await
-        .expect("Could not initialize coconut credential");
-
         // currently we do not care about acks at all, but we must keep the channel alive
         // so that the gateway client would not crash
         let (ack_sender, ack_receiver) = mpsc::unbounded();
@@ -136,7 +135,7 @@ impl PacketSender {
                 message_sender,
                 ack_sender,
                 fresh_gateway_client_data.gateway_response_timeout,
-                coconut_credential,
+                fresh_gateway_client_data.bandwidth_credential.clone(),
             ),
             (message_receiver, ack_receiver),
         )