node-opalcoin is a Opalcoin client for Node.js. It is a fork of node-dogecoin client (see fork) intended for use with Opalcoin. The purpose of this repository is:
- Provide a one-stop resource for the Node.js developer to get started with Opalcoin integration.
- Prevent would-be Opalcoin web developers worrying whether a DogeCoin client will work out of the box.
- Promote Node.js development of Opalcoin web apps.
- Identify and address any incompatibilities with the Opalcoin and DogeCoin APIs that exist now and/or in the future.
You'll need a running instance of opalcoind to connect with.
Then, install the node-opalcoin NPM package.
npm install node-opalcoin
var opalcoin = require('node-opalcoin')()
opalcoin.auth('myusername', 'mypassword')
opalcoin.getDifficulty(function() {
console.log(arguments);
})
You may pass options to the initialization function or to the set
method.
var opalcoin = require('opalcoin')({
user:'user'
})
opalcoin.set('pass', 'somn')
opalcoin.set({port:22555})
Available options and default values:
- host 127.0.0.1
- port 45443
- user
- pass
- passphrasecallback
- https
- ca
With an encryped wallet, any operation that accesses private keys requires a wallet unlock. A wallet is unlocked using the walletpassphrase <passphrase> <timeout>
JSON-RPC method: the wallet will relock after timeout
seconds.
You may pass an optional function passphrasecallback
to the node-opalcoin
initialization function to manage wallet unlocks. passphrasecallback
should be a function accepting three arguments:
function(command, args, callback) {}
- command is the command that failed due to a locked wallet.
- args is the arguments for the failed command.
- callback is a typical node-style continuation callback of the form
function(err, passphrase, timeout) {}
. Call callback with the wallet passphrase and desired timeout from within your passphrasecallback to unlock the wallet.
You may hard code your passphrase (not recommended) as follows:
var opalcoin = require('node-opalcoin')({
passphrasecallback: function(command, args, callback) {
callback(null, 'passphrase', 30);
}
})
Because passphrasecallback
is a continuation, you can retrieve the passphrase in an asynchronous manner. For example, by prompting the user:
var readline = require('readline')
var rl = readline.createInterface({
input: process.stdin,
output: process.stdout
})
var opalcoin = require('node-opalcoin')({
passphrasecallback: function(command, args, callback) {
rl.question('Enter passphrase for "' + command + '" operation: ', function(passphrase) {
if (passphrase) {
callback(null, passphrase, 1)
} else {
callback(new Error('no passphrase entered'))
}
})
}
})
By default opalcoind
exposes its JSON-RPC interface via HTTP; that is, all RPC commands are transmitted in plain text across the network! To secure the JSON-RPC channel you can supply opalcoind
with a self-signed SSL certificate and an associated private key to enable HTTPS. For example, in your opalcoin.conf
:
rpcssl=1
rpcsslcertificatechainfile=/etc/ssl/certs/opalcoind.crt
rpcsslprivatekeyfile=/etc/ssl/private/opalcoind.pem
In order to securely access an SSL encrypted JSON-RPC interface you need a copy of the self-signed certificate from the server: in this case opalcoind.crt
. Pass your self-signed certificate in the ca
option and set https: true
and node-opalcoin is secured!
var fs = require('fs')
var ca = fs.readFileSync('opalcoind.crt')
var opalcoin = require('node-opalcoin')({
user: 'rpcusername',
pass: 'rpcpassword',
https: true,
ca: ca
})