Overview

Hush Lightwalletd is a fork of lightwalletd original from Zcash (ZEC).

It is a backend service that provides a bandwidth-efficient interface to the Hush blockchain for SilentDragonLite cli and SilentDragonLite.

Changes from upstream lightwalletd

This version of lightwalletd extends lightwalletd and:

• Adds support for HUSH
• Adds support for transparent addresses
• Adds several new RPC calls for lightclients
• Lots of perf improvements
  • Replaces SQLite with in-memory cache for Compact Blocks
  • Replace local Txstore, delegating Tx lookups to hushd
  • Remove the need for a separate ingestor

Running your own SDL lightwalletd

0. First, install Go

You will need Go >= 1.13 which you can download from the official download page or install via your OS package manager.

This installation document shows how to do it on various OS's.

If you're using Ubuntu or Debian, try:

$ sudo apt install golang

1. Run a Hush node.

Either compile or build the Hush Daemon (hushd).

Next, change your HUSH3.conf file to something like the following:

rpcuser=user-CHANGETHIS
rpcpassword=pass-CHANGETHIS
rpcport=18031
server=1
txindex=1
rpcworkqueue=256
rpcallowip=127.0.0.1
rpcbind=127.0.0.1

Then start hushd in your command window. You might need to run with -reindex the first time if you are enabling the txindex or insightexplorer options for the first time. The reindex might take a while.

2. Compile lightwalletd

Run the build script.

make

3. Get a TLS certificate and run the Lightwalletd frontend

First, get a TLS certificate:

On Ubuntu Linux, I SUGGEST YOU DO NOT USE SNAPD and just sudo apt install certbot and then start on Step 7 of these instructions by the EFF

Next you decide how you want to setup lightwalletd - with (Option A) or without NGINX (Option B).

Option A: "Let's Encrypt" certificate using NGINX as a reverse proxy

If you running a public-facing server, the easiest way to obtain a certificate is to use a NGINX reverse proxy and get a Let's Encrypt certificate.

Create a new section for the NGINX reverse proxy:

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    
    server_name your_host.net;

    ssl_certificate /etc/letsencrypt/live/your_host.net/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/your_host.net/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
        
    location / {
        # Replace localhost:9067 with the address and port of your gRPC server if using a custom port
    	grpc_pass grpc://your_host.net:9067;
    }
}

Then run the lightwalletd frontend with the following (Note: we use the "-no-tls" option as we are using NGINX as a reverse proxy and letting it handle the TLS authentication for us instead):

./lightwalletd -bind-addr your_host.net:9067 -conf-file ~/.hush/HUSH3/HUSH3.conf -no-tls

Option B: "Let's Encrypt" certificate just using lightwalletd without NGINX

The other option is to configure lightwalletd to handle its own TLS authentication. Once you have a certificate that you want to use (from a certificate authority), pass the certificate to the frontend as follows:

./lightwalletd -bind-addr 127.0.0.1:9067 -conf-file ~/.hush/HUSH3/HUSH3.conf -tls-cert /etc/letsencrypt/live/YOURWEBSITE/fullchain.pem -tls-key /etc/letsencrypt/live/YOURWEBSITE/privkey.pem

4. Point the silentdragonlite-cli to this server

You should start seeing the frontend ingest and cache the Hush blocks after ~15 seconds.

Now, connect to your server! (Substitute with your own below)

git clone https://git.hush.is/hush/silentdragonlite-cli
cd silentdragonlite-cli
cargo build --release
./target/release/silentdragonlite-cli --server https://lite.example.org

• If you have trouble compiling silentdragonlite-cli, then please refer to it's separate documentation here on how to build it and what pre-requisites need to be installed.

Lightwalletd Command-line Options

These are the current different command line options for lightwalletd:

CLI option	Default	What it does
-bind-addr	127.0.0.1:9067	address and port to listen on
-tls-cert	blank	the path to a TLS certificate
-tls-key	blank	the path to a TLS key file
-no-tls	false	Disable TLS, serve un-encrypted traffic
-log-file	blank	log file to write to
-log-level	logrus.InfoLevel	log level 1 thru 7 (something from logrus)
-conf-file	blank	conf file to pull RPC creds from
-cache-size	40000	number of blocks to hold in the cache

Support

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License

GPLv3 or later