Using non-module format JS libraries with Webpack.

  npm install imports-loader
  npm install exports-loader

/* ... 
Your webpack.config.js specific settings.
.... */
 
module.exports = {
 /* ... */
  module: {
    loaders: [
      {
        test: /jsbn\.js$/,
        loaders: [
          'exports?BigInteger=BigInteger',
          'exports?IntAt=intAt',
          'exports?Nbv=nbv',
          'exports?Montgomery=Montgomery',
          'exports?Nbi=nbi',
          'exports?Nbits=nbits'
        ]
      },
      {
        test: /jsbn2\.js$/,
        loaders: [
          'imports?BigInteger=>JsbnWrapper.BigInteger',
          'imports?nbi=>JsbnWrapper.Nbi',
          'imports?intAt=>JsbnWrapper.IntAt',
          'imports?nbv=>JsbnWrapper.Nbv',
          'imports?Montgomery=>JsbnWrapper.Montgomery',
          'imports?nbits=>JsbnWrapper.Nbits'
        ]
      },
      {
        test: /amazon-cognito-identity\.min\.js$/,
        loaders: [
          'imports?BigInteger=>JsbnWrapper.BigInteger'
        ]
      }
    ]
  }
};

// In your main entry point js file.
 
// webpack.config.js is configured to export a series of variables that we'll also import into jsbn2 and the AWS SDK.
JsbnWrapper = require("./js/lib/utils/jsbn.js");
// Webpack.config.js will import variables into this file that were exported from jsbn.js.
require('./js/lib/utils/jsbn2.js');
// Set "sjcl" to the global scope.
sjcl = require('sjcl');
require('./node_modules/amazon-cognito-identity-js/dist/aws-cognito-sdk.min.js');
require('./node_modules/amazon-cognito-identity-js/dist/amazon-cognito-identity.min.js');