Half-baked HTTP/HTTPS Digest Authentication for node.js.

digest.js

var http = require("http");
var https = require("https");
var crypto = require('crypto');

function HTTPDigest(username, password, use_https) {
	this.username = username;
	this.password = password;
	this.use_https = use_https;
}

HTTPDigest.prototype.request = function(options, body, callback) {
	var request_method = this.use_https ? https.request : http.request;
	var self = this;

	request_method(options, function(response) {
		self._handle_response(options, response, body, callback);
	}).on("error", function(e) {
		console.error(e);
	}).end();
}

HTTPDigest.prototype._handle_response = function(options, response, body, callback) {
	var request_method = this.use_https ? https.request : http.request;
	var challenge = this._parse_challenge(response.headers["www-authenticate"]);

	var ha1 = crypto.createHash("md5");
	ha1.update([this.username, challenge.realm, this.password].join(":"));

	var ha2 = crypto.createHash("md5");
	ha2.update([options.method, options.path].join(":"));

	var response = crypto.createHash("md5");
	response.update([ha1.digest("hex"), challenge.nonce, ha2.digest("hex")].join(":"));

	var requestParams = {
		"username": this.username,
		"realm": challenge.realm,
		"nonce": challenge.nonce,
		"uri": options.path,
		"qop": challenge.qop,
		"response": response.digest("hex"),
		"nc": "1",
		"cnonce": ""
	};
	options.headers = options.headers || {};
	options.headers.Authorization = this._render_digest(requestParams);

	request_method(options, function(response) {
		response.setEncoding("utf8");
		var content = "";

		response.on("data", function(chunk) {
			content += chunk;
		}).on("end", function() {
			callback(content);
		});
	}).end(body);
}

HTTPDigest.prototype._parse_challenge = function(header) {
	var prefix = "Digest ";
	var challenge = header.substr(header.indexOf(prefix) + prefix.length);
	var parts = challenge.split(",");
	var length = parts.length;
	var params = {};
	for (var i = 0; i < length; i++) {
	  var part = parts[i].match(/^\s*?([a-zA-Z0-0]+)="(.*)"\s*?$/);
	  if (part && part.length > 2) {
	    params[part[1]] = part[2];
	  }
	}

	return params;
}

HTTPDigest.prototype._render_digest = function(params) {
	var parts = [];
	for (var i in params) {
	  parts.push(i + "=\"" + params[i] + "\"");
	}
	return "Digest " + parts.join(",");
}

module.exports = HTTPDigest