(JavaScript) Generate an AWS (S3) Pre-Signed URL to Download File

Demonstrates how to generate a pre-signed URL to download a file from the Amazon S3 service.

Note: This example requires Chilkat v11.0.0 or greater.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

var http = new CkHttp();

http.AwsAccessKey = "AWS_ACCESS_KEY";
http.AwsSecretKey = "AWS_SECRET_KEY";

// Make sure to set your AWS region correctly
http.AwsRegion = "us-east-1";

var bucketName = "chilkat100";
var objectName = "starfish/starfish.jpg";
var localFilePath = "qa_output/starfish.jpg";
var awsService = "s3";

// The signed URL will be valid for this number of seconds:
var numSecondsValid = 86400;

// Choose between a URL beginning with "http://" or "https://"...
var bUseHttps = false;

// Generate the pre-signed URL
var preSignedUrl = http.S3_GenPresignedUrl("GET",bUseHttps,bucketName,objectName,numSecondsValid,awsService);
if (http.LastMethodSuccess == false) {
    console.log(http.LastErrorText);
    return;
}

// The following URL can be copy-and-pasted into a browser..
console.log("Pre-Signed AWS S3 URL: " + preSignedUrl);

// Here's an example of a pre-signed URL. 
// This URL will only work within 1 day (86400 seconds) after the time this example was published.
// 
//     http://chilkat100.s3.amazonaws.com/starfish/starfish.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=16QXXDGY83AJJR6RVQ02%2F20170111%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Date=20170111T161959Z&X-Amz-Expires=86400&X-Amz-SignedHeaders=host&X-Amz-Signature=72bf4fd9a15d7bbcdd313a3318d937a778905f62a3fbff9b789d8dc28acd9232

// Now try to do an HTTP Download using the signed URL.
success = http.Download(preSignedUrl,"c:/temp/qa_output/starfish.jpg");
if (success == false) {
    console.log(http.LastErrorText);
    return;
}

console.log("Success.");