add TLS support

dshackle-cli/src/grpc-clent.js

@@ -1,6 +1,7 @@
 const grpc = require("@grpc/grpc-js");
 const path = require('path')
 const protoLoader = require("@grpc/proto-loader");
+const fs = require('fs');
 
 const PROTO_PATH = path.join(__dirname, "../grpc/proto/blockchain.proto");
 
@@ -15,11 +16,21 @@ const options = {
 const packageDefinition = protoLoader.loadSync(PROTO_PATH, options);
 const emerald = grpc.loadPackageDefinition(packageDefinition).emerald
 
-export function describe(url, handler) {
+export function describe(url, ca, cert, key, handler) {
+    let credentials = grpc.credentials.createInsecure()
+    if (ca || cert || key) {
+        console.log("Using TLS")
+        credentials = grpc.credentials.createSsl(
+            ca ? fs.readFileSync(ca) : null,
+            key ? fs.readFileSync(key) : null,
+            cert ? fs.readFileSync(cert) : null
+        );
+    }
     const client = new emerald.Blockchain(
         url,
-        grpc.credentials.createInsecure()
+        credentials
     );
+
     console.log('Connecting to: ' + url + '...')
     client.Describe({}, handler);
 }