(Swift) 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.

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    var success: Bool = false

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

    let http = CkoHttp()!

    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: String? = "chilkat100"
    var objectName: String? = "starfish/starfish.jpg"
    var localFilePath: String? = "qa_output/starfish.jpg"
    var awsService: String? = "s3"

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

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

    // Generate the pre-signed URL
    var preSignedUrl: String? = http.s3_GenPresignedUrl("GET", useHttps: bUseHttps, bucketName: bucketName, path: objectName, numSecondsValid: numSecondsValid, awsService: awsService)
    if http.lastMethodSuccess == false {
        print("\(http.lastErrorText!)")
        return
    }

    // The following URL can be copy-and-pasted into a browser..
    print("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, saveToPath: "c:/temp/qa_output/starfish.jpg")
    if success == false {
        print("\(http.lastErrorText!)")
        return
    }

    print("Success.")

}