(PowerBuilder) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
integer li_Success
oleobject loo_Http
string ls_BucketName
string ls_ObjectName
string ls_LocalFilePath
string ls_AwsService
integer li_NumSecondsValid
integer li_BUseHttps
string ls_PreSignedUrl

li_Success = 0

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

loo_Http = create oleobject
li_rc = loo_Http.ConnectToNewObject("Chilkat.Http")
if li_rc < 0 then
    destroy loo_Http
    MessageBox("Error","Connecting to COM object failed")
    return
end if

loo_Http.AwsAccessKey = "AWS_ACCESS_KEY"
loo_Http.AwsSecretKey = "AWS_SECRET_KEY"

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

ls_BucketName = "chilkat100"
ls_ObjectName = "starfish/starfish.jpg"
ls_LocalFilePath = "qa_output/starfish.jpg"
ls_AwsService = "s3"

// The signed URL will be valid for this number of seconds:
li_NumSecondsValid = 86400

// Choose between a URL beginning with "http://" or "https://"...
li_BUseHttps = 0

// Generate the pre-signed URL
ls_PreSignedUrl = loo_Http.S3_GenPresignedUrl("GET",li_BUseHttps,ls_BucketName,ls_ObjectName,li_NumSecondsValid,ls_AwsService)
if loo_Http.LastMethodSuccess = 0 then
    Write-Debug loo_Http.LastErrorText
    destroy loo_Http
    return
end if

// The following URL can be copy-and-pasted into a browser..
Write-Debug "Pre-Signed AWS S3 URL: " + ls_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.
li_Success = loo_Http.Download(ls_PreSignedUrl,"c:/temp/qa_output/starfish.jpg")
if li_Success = 0 then
    Write-Debug loo_Http.LastErrorText
    destroy loo_Http
    return
end if

Write-Debug "Success."


destroy loo_Http