DataFlex

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

See more Amazon S3 (new) Examples

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

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoHttp
    String sBucketName
    String sObjectName
    String sLocalFilePath
    String sAwsService
    Integer iNumSecondsValid
    Boolean iBUseHttps
    String sPreSignedUrl
    String sTemp1
    Boolean bTemp1

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    Set ComAwsAccessKey Of hoHttp To "AWS_ACCESS_KEY"
    Set ComAwsSecretKey Of hoHttp To "AWS_SECRET_KEY"

    // Make sure to set your AWS region correctly
    Set ComAwsRegion Of hoHttp To "us-east-1"

    Move "chilkat100" To sBucketName
    Move "starfish/starfish.jpg" To sObjectName
    Move "qa_output/starfish.jpg" To sLocalFilePath
    Move "s3" To sAwsService

    // The signed URL will be valid for this number of seconds:
    Move 86400 To iNumSecondsValid

    // Choose between a URL beginning with "http://" or "https://"...
    Move False To iBUseHttps

    // Generate the pre-signed URL
    Get ComS3_GenPresignedUrl Of hoHttp "GET" iBUseHttps sBucketName sObjectName iNumSecondsValid sAwsService To sPreSignedUrl
    Get ComLastMethodSuccess Of hoHttp To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // The following URL can be copy-and-pasted into a browser..
    Showln "Pre-Signed AWS S3 URL: " sPreSignedUrl

    // 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.
    Get ComDownload Of hoHttp sPreSignedUrl "c:/temp/qa_output/starfish.jpg" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Success."


End_Procedure