AWS CloudFront URL Signature Utility (Signed Cookies)

Generating signed cookies for CloudFront links is a little more tricky than for S3. It's because signature generation for S3 URLs is handled a bit differently than CloudFront URLs and this functionality is not currently supported by the aws-sdk library for JavaScript. In case you also need to do this, I've created this simple utility to make things easier. Inspired by https://github.com/jasonsims/aws-cloudfront-sign

Usage

Requirements

Node.js >=0.10.0 or io.js latest
Active CloudFront distribution with origin configured

Configuring CloudFront

Create a CloudFront distribution
Configure your origin with the following settings:

Origin Domain Name: {your-s3-bucket}
Restrict Bucket Access: Yes
Grant Read Permissions on Bucket: Yes, Update Bucket Policy
Create CloudFront Key Pair.

Options

expireTime (Optional - Default: 30s) - The time when the URL should expire. Accepted values are
- number - Time in milliseconds (new Date().getTime() + 30000)
- moment - Valid momentjs object (moment().add(1, 'day'))
- Date - Javascript Date object (new Date(2016, 0, 1))
keypairId - The access key ID from your Cloudfront keypair

privateKeyString || privateKeyPath - The private key from your Cloudfront keypair. It can be provided as either a string or a path to the .pem file. Note: When providing the private key as a string, ensure that the newline character is also included.

var privateKeyString =
  '-----BEGIN RSA PRIVATE KEY-----\n'
  'MIIJKAIBAAKCAgEAwGPMqEvxPYQIffDimM9t3A7Z4aBFAUvLiITzmHRc4UPwryJp\n'
  'EVi3C0sQQKBHlq2IOwrmqNiAk31/uh4FnrRR1mtQm4x4IID58cFAhKkKI/09+j1h\n'
  'tuf/gLRcOgAXH9o3J5zWjs/y8eWTKtdWv6hWRxuuVwugciNckxwZVV0KewO02wJz\n'
  'jBfDw9B5ghxKP95t7/B2AgRUMj+r47zErFwo3OKW0egDUpV+eoNSBylXPXXYKvsL\n'
  'AlznRi9xNafFGy9tmh70pwlGG5mVHswD/96eUSuLOZ2srcNvd1UVmjtHL7P9/z4B\n'
  'KdODlpb5Vx+54+Fa19vpgXEtHgfAgGW9DjlZMtl4wYTqyGAoa+SLuehjAQsxT8M1\n'
  'BXqfMJwE7D9XHjxkqCvd93UGgP+Yxe6H+HczJeA05dFLzC87qdM45R5c74k=\n'
  '-----END RSA PRIVATE KEY-----'

Also, here are some examples if prefer to store your private key as a string but within an environment variable.

# Local env example
CF_PRIVATE_KEY="$(cat your-private-key.pem)"

# Heroku env
heroku config:set CF_PRIVATE_KEY="$(cat your-private-key.pem)"

Examples

Creating a signed URL

var cf = require('aws-cloudfront-sign-cookies')
var options = {keypairId: 'APKAJM2FEVTI7BNPCY4A', privateKeyPath: '/foo/bar'}
var signedCookiesObject = cf.getSignedUrl('http://xxxxxxx.cloudfront.net/*', options);
console.log('Signed URL: ' + signedCookiesObject);

polomoshnov / aws-cloudfront-sign-cookies