Example to generate Signed URLs in CloudFront using Custom Policy.

CloudFront Signed URL Custom Policy.js

const AWS = require('aws-sdk');

// Try to use process.env.PRIVATE_KEY instead of exposing your key
const privateKey = `-----BEGIN RSA PRIVATE KEY-----
  XXXXXXXX
  XXXXXXXX
  XXXXXXXX
  XXXXXXXX
-----END RSA PRIVATE KEY-----`

const cloudFront = new AWS.CloudFront.Signer('PUBLIC_ACCESS_KEY', privateKey);

const policy = JSON.stringify({
  "Statement": [
    {
      "Resource": "https://abcdefghijklmn.cloudfront.net/test/a.txt",
      "Condition": {
        "DateLessThan": {
          "AWS:EpochTime": Math.floor((new Date()).getTime() / 1000) + (60 * 60 * 1) // Current Time in UTC + time in seconds, (60 * 60 * 1 = 1 hour)
        }
      }
    }
  ]
});

cloudFront.getSignedUrl({
  policy,
}, (err, url) => {
  if (err) throw err;
  console.log(url);
});

@immma You have to give a url param to prevent this error.

same issue TypeError: Cannot read property 'split' of undefined

It is caused by this line in the SDK. It seems it is necessary to provide the Resource URL as url property to the options argument.

//  ... same as gist
cloudFront.getSignedUrl({
  url: <resource_url_here_as_string>
  policy,
}, (err, url) => {
  if (err) throw err;
  console.log(url);
});