(PureBasic) Generate an AWS (S3) Pre-Signed URL using Signature V4

Demonstrates how to generate a pre-signed URL using AWS Signature Version 4. This example generates a pre-signed URL for the Amazon S3 service.

Note: this example requires Chilkat v9.5.0.66 or greater.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkHttp.pb"

Procedure ChilkatExample()

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

    ; Note: This example requires Chilkat v9.5.0.66 or greater.

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttp::setCkAwsAccessKey(http, "AWS_ACCESS_KEY")
    CkHttp::setCkAwsSecretKey(http, "AWS_SECRET_KEY")

    ; Make sure to set your AWS region correctly
    CkHttp::setCkAwsRegion(http, "us-east-1")

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

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

    ; Choose between a URL beginning with "http://" or "https://"...
    bUseHttps.i = 0

    ; Generate the pre-signed URL
    preSignedUrl.s = CkHttp::ckS3_GenerateUrlV4(http,bUseHttps,bucketName,objectName,numSecondsValid,awsService)
    If CkHttp::ckLastMethodSuccess(http) <> 1
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf

    ; The following URL can be copy-and-pasted into a browser..
    Debug "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.i = CkHttp::ckDownload(http,preSignedUrl,"qa_output/starfish.jpg")
    If success <> 1
        Debug CkHttp::ckLastErrorText(http)
    Else
        Debug "Success."
    EndIf



    CkHttp::ckDispose(http)


    ProcedureReturn
EndProcedure