aws3

Signs and prepares requests using AWS Signature Version 3

npm install aws3
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aws3

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A small utility to sign vanilla node.js http(s) request options using Amazon's AWS Signature Version 3.

This signature is supported only be a couple of Amazon services: SWF and Route53.

It also provides defaults for a number of core AWS headers and request parameters, making it a very easy to query AWS services, or build out a fully-featured AWS library.

NB: It is preferrable to use the more secure aws4 over this library for AWS services that support AWS Signature Version 4.

Example

var https = require('https')
  , aws3  = require('aws3')

// given an options object you could pass to http.request
var opts = { host: 'route53.amazonaws.com', path: '/2012-02-29/hostedzone' }

aws3.sign(opts) // assumes AWS credentials are available in process.env

console.log(opts)
/*
{
  host: 'route53.amazonaws.com',
  path: '/2012-02-29/hostedzone',
  headers: {
    Host: 'route53.amazonaws.com'
    'X-Amz-Date': 'Mon, 14 Jan 2013 08:02:29 GMT',
    'X-Amzn-Authorization': 'AWS3-HTTPS AWSAccessKeyId=ABCDEF1234567890,Algorithm=HmacSHA256,Signature=/frrTLlefAd19DcPY9LJarRejLxf3NiHZXN/t0VJJTs='
  }
}
*/

// we can now use this to query AWS using the standard node.js http API
https.request(opts, function(res) { res.pipe(process.stdout) }).end()
/*
<ListHostedZonesResponse xmlns="https://route53.amazonaws.com/doc/2012-02-29/">
...
*/

// you can pass AWS credentials in explicitly
aws3.sign(opts, { accessKeyId: '', secretAccessKey: '' })

// aws3 can infer the host from a service and (optional) region
opts = aws3.sign({ service: 'route53', path: '/2012-02-29/hostedzone' })

// can specify any custom option or header as per usual
opts = aws3.sign({
  service: 'swf',
  region: 'us-east-1',
  body: '{"registrationStatus":"REGISTERED"}',
  headers: {
    'Content-Type': 'application/x-amz-json-1.0',
    'X-Amz-Target': 'SimpleWorkflowService.ListDomains'
  }
})

https.request(opts, function(res) { res.pipe(process.stdout) }).end(opts.body)
/*
{"domainInfos":[]}
...
*/

API

aws3.sign(requestOptions, [credentials])

This calculates and populates the X-Amzn-Authorization header of requestOptions, and any other necessary AWS headers and/or request options. Returns requestOptions as a convenience for chaining.

requestOptions is an object holding the same options that the node.js http.request function takes.

The following properties of requestOptions are used in the signing or populated if they don't already exist:

  • hostname or host (will be determined from service and region if not given)
  • method (will use 'GET' if not given or 'POST' if there is a body)
  • path (will use '/' if not given)
  • body (will use '' if not given)
  • service (will be calculated from hostname or host if not given)
  • region (will be calculated from hostname or host or use 'us-east-1' if not given)
  • headers['Host'] (will use hostname or host or be calculated if not given)
  • headers['Content-Type'] (will use 'text/xml' if not given and there is a body)
  • headers['Date'] (used to calculate the signature date if given, otherwise new Date is used)

Your AWS credentials (which can be found in your AWS console) can be specified in one of two ways:

  • As the second argument, like this:
aws3.sign(requestOptions, {
  secretAccessKey: "<your-secret-access-key>",
  accessKeyId: "<your-access-key-id>"
})
  • From process.env, such as this:
export AWS_SECRET_ACCESS_KEY="<your-secret-access-key>"
export AWS_ACCESS_KEY_ID="<your-access-key-id>"

(will also use AWS_ACCESS_KEY and AWS_SECRET_KEY if available)

Installation

With npm do:

npm install aws3
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