(VB.NET) Bunny Sign URL and then Download using Signed URL

See more Bunny CDN Examples

Shows how to sign a URL for BunnyCDN Token Authentication and then use it to download.

For more information, see https://support.bunny.net/hc/en-us/articles/360016055099-How-to-sign-URLs-for-BunnyCDN-Token-Authentication

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Dim success As Boolean
Dim mySecurityKey As String = "e7ea8d73-8fa0-44ef-a2cc-91526f7df5ed"

Dim url As String = "https://test.b-cdn.net/sample-pdf-with-images.pdf"

' Extract the URL components.
Dim urlObj As New Chilkat.Url
urlObj.ParseUrl(url)

Dim url_scheme As String = "https"
If (urlObj.Ssl = False) Then
    url_scheme = "http"
End If


Dim url_host As String = urlObj.Host
Dim url_path As String = urlObj.Path

' Calculate an expiration time 1 hour from the current date/time.
Dim expTime As New Chilkat.CkDateTime
expTime.SetFromCurrentSystemTime()
expTime.AddSeconds(3600)
Dim expires As String = expTime.GetAsUnixTimeStr(False)

Debug.WriteLine("Expires = " & expires)

' Create the string to hash
Dim sbToHash As New Chilkat.StringBuilder
sbToHash.Append(mySecurityKey)
sbToHash.Append(url_path)
sbToHash.Append(expires)

' Base64Url encoding is the same as base64, except "-" is used instead of "+",
' "_" is used instead of "/", and no "=" padding is added.
Dim token As String = sbToHash.GetHash("sha256","base64Url","utf-8")

Dim sbSignedUrl As New Chilkat.StringBuilder
sbSignedUrl.Append(url_scheme)
sbSignedUrl.Append("://")
sbSignedUrl.Append(url_host)
sbSignedUrl.Append(url_path)
sbSignedUrl.Append("?token=")
sbSignedUrl.Append(token)
sbSignedUrl.Append("&expires=")
sbSignedUrl.Append(expires)

Dim signedUrl As String = sbSignedUrl.GetAsString()
Debug.WriteLine("Signed URL: " & signedUrl)

' Use the signed URL to download the file.
Dim http As New Chilkat.Http
success = http.Download(signedUrl,"c:/aaworkarea/sample.pdf")
If (success = False) Then
    Debug.WriteLine(http.LastErrorText)
Else
    Debug.WriteLine("Success.")
End If