vaishakhcherukat/aws-sign-web

Plain JavaScript AWS Signature v4 for use within Web Browsers

aws-sign-web

Plain JavaScript AWS Signature v4 for use within Web Browsers

Example: Plain JavaScript

<script src="bower_components/cryptojslib/rollups/sha256.js"></script>
<script src="bower_components/cryptojslib/rollups/hmac-sha256.js"></script>
<script src="bower_components/aws-sign-web/aws-sign-web.min.js"></script>

<script type="text/javascript">
(function() {
    // Create a new signer
    var config = {
        // AWS Region (default: 'eu-west-1')
        region: 'eu-west-1',
        // AWS service that is called (default: 'execute-api' -- AWS API Gateway)
        service: 'execute-api',
        // AWS IAM credentials, here some temporary credentials with a session token
        accessKeyId: '...',
        secretAccessKey: '...',
        sessionToken: '...'
    };
    var signer = new awsSignWeb.AwsSigner(config);

    // Sign a request
    var request = {
        method: 'GET',
        url: 'https://<YOUR_API>.execute-api.eu-west-1.amazonaws.com/dev/users',
        headers: {},
        params: {
            'username': 'nobody'
        },
        data: null
    };
    var signed = signer.sign(request);
    console.log(signed);

    ///
    /// {
    ///     'Accept': 'application/json',
    ///     'Authorization': 'AWS4-HMAC-SHA256 Credential=ASIAIQTP2FX4MJ4J2DIA/20160520/eu-west-1/execute-api/aws4_request, SignedHeaders=accept;host;x-amz-date, Signature=cc870c6ea5174baad470e46a7f5642725ff9411e049cf24d730923fca7e5f2b4'
    ///     'x-amz-date': '20160520T053201Z',
    ///     'x-amz-security-token': 'FQoDYXdzEOf//...'
    /// }
    ///
})();
</script>

Example: AngularJS $http interceptor

The example assumes that the aws-sign-web is loaded inside the index.html such that it exposes the global variable awsSignWeb. The following code snippet shows how to create and configure an interceptor for Angular's $http provider.

/* global AwsSigner */

angular
    .module('mymodule')
    .factory('AwsAuthInterceptor', function () {
        var defaultAuthConfig = {
            region: 'eu-west-1',
            service: 'execute-api'
        };
        return {
            request: onRequest
        };

        function onRequest(config) {
            if (angular.isUndefined(config.awsAuth) || !config.awsAuth) {
                return config;
            }
            var authConfig = angular.extend({}, defaultAuthConfig, config.awsAuth);
            delete config.awsAuth;
            if (angular.isUndefined(authConfig.accessKeyId) ||
                angular.isUndefined(authConfig.secretAccessKey)) {
                return config;
            }
            // Re-use existing request transformers for generating the payload.
            if (config.transformRequest) {
                authConfig.payloadSerializer = function() {
                    return config.transformRequest.reduce(function(prev, transformer) {
                        return transformer(prev);
                    }, config.data);
                };
            }
            // Create the authentication headers and merge them into the existing ones
            var signer = new awsSignWeb.AwsSigner(authConfig);
            var signed = signer.sign(config);
            angular.merge(config.headers, signed);
            return config;
        }
    })
    .config(function ($httpProvider) {
        $httpProvider.interceptors.push('AwsAuthInterceptor');
    });

Use the above interceptor, e.g. in combination with Restangular:

Restangular.all('users')
    .withHttpConfig({
        awsAuth: {
            accessKeyId: '...',
            secretAccessKey: '...',
            sessionToken: '...'
        }
    })
    .get('johndoe')
    .then(...);