添加 captchapng

+/**
+ * Created by TaoHuang on 2016/7/1.
+ */
+
+'use strict';
+
+const _ = require('lodash');
+const Captchapng = require('captchapng');
+
+exports.generateCaptcha = (width, height, length) => {
+    let min = Math.pow(10, (length - 1 || 1));
+    let max = Math.pow(10, (length - 1 || 1)) * 9;
+    let token = '' + _.random(min, max);
+
+    let png = new Captchapng(width, height, token);//
+
+    png.color(0, 0, 0, 0);  // First color: background (red, green, blue, alpha)
+    png.color(80, 80, 80, 255); // Second color: paint (red, green, blue, alpha)
+
+    return {
+        image: new Buffer(png.getBase64(), 'base64'),
+        text: token
+    };
+};

@@ -20,6 +20,7 @@
   "dependencies": {
     "bluebird": "^3.4.6",
     "body-parser": "^1.15.2",
+    "captchapng": "0.0.1",
     "cheerio": "^0.22.0",
     "compression": "^1.6.2",
     "connect-multiparty": "^2.0.0",