(VB.NET UWP/WinRT) (using AWS Signature Version 2) Streaming Download to File

The main purpose of this example is to demonstrate how to use the older Signature Version 2 authentication w/ S3. It uses V2 authentication to download a file.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

Dim rest As New Chilkat.Rest

' Connect to the Amazon AWS REST server.
Dim bTls As Boolean = True
Dim port As Integer = 443
Dim bAutoReconnect As Boolean = True
' The file is located in the bucket named "chilkat100", which becomes part of the domain:
Dim success As Boolean = Await rest.ConnectAsync("chilkat100.s3.amazonaws.com",port,bTls,bAutoReconnect)

' Provide AWS credentials for the REST call.
Dim authAws As New Chilkat.AuthAws
authAws.AccessKey = "AWS_ACCESS_KEY"
authAws.SecretKey = "AWS_SECRET_KEY"
authAws.ServiceName = "s3"

' For AWS Signature Version 2, the following two properties need to be set:
authAws.SignatureVersion = 2
' See http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#ConstructingTheCanonicalizedResourceElement
authAws.CanonicalizedResourceV2 = "/chilkat100/starfish.jpg"

success = rest.SetAuthAws(authAws)

' Send the request to download the JPG.
success = Await rest.SendReqNoBodyAsync("GET","/starfish.jpg")
If (success <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


' Read the response header.
Dim responseStatusCode As Integer = Await rest.ReadResponseHeaderAsync()
If (responseStatusCode < 0) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Response status code = " & responseStatusCode)

' We expect a 200 response status if the JPG data is coming.
' Otherwise, we'll get a string response body with an error message(or no response body).
If (responseStatusCode = 200) Then

    Dim bodyStream As New Chilkat.Stream

    ' The stream's sink will be a file.
    bodyStream.SinkFile = "qa_output/starfish.jpg"

    ' Read the response body to the stream.  Given that we've
    ' set the stream's sink to a file, it will stream directly
    ' to the file.
    success = Await rest.ReadRespBodyStreamAsync(bodyStream,True)
    If (success <> True) Then
        Debug.WriteLine(rest.LastErrorText)
        Exit Sub
    End If


    Debug.WriteLine("Successfully received the JPG file.")

Else
    Dim errResponse As String = Await rest.ReadRespBodyStringAsync()
    If (rest.LastMethodSuccess <> True) Then
        Debug.WriteLine(rest.LastErrorText)
    Else
        Debug.WriteLine(errResponse)
    End If

End If