Access dropbox file - The remote server returned an error: (404) Not Found

[Lukager1]

i'm new in this type of access.
I wrote this code but i have the error in objet to recover the list of files in dropbox.

        Dim token As String
        token = "sl.B6........."
        Dim _command As String
        _command = "https://api.dropboxapi.com/2/files/list_folder"

        Dim Request As HttpWebRequest
        Request = HttpWebRequest.Create(_command)

        Request.Method = "GET"
        Request.KeepAlive = True
        Request.ContentType = "application/x-www-form-urlencoded"
        Request.UserAgent = "Mozilla/5.0 (Windows NT 6.3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.154 Safari/537.36"
        Request.AllowAutoRedirect = True
        Request.Headers.Add("Authorization", "Bearer " & token)

        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12

        Dim Response As HttpWebResponse = Request.GetResponse()

[dday9]

404 typically means that it cannot find the file you're requesting.

It looks like you're hitting the files/list_folder endpoint (documentation). To be honest, I'm a bit surprised you're getting a 404.

But looking at the documentation it looks like you've setup your headers incorrectly. The ContentType should be application/json. I don't think that's the underlying issue, but it's worth changing nonetheless.

[Lukager1]

ty.
I changed it and now the error is ::
Authentication failed because the remote party has closed the transport stream.
i try to change this ...
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12
with or without i have the same error.

[dday9]

That does suggest a security issue. Try moving the call further up in your code and additionally specify more options:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 Or SecurityProtocolType.Tls12 Or SecurityProtocolType.Tls11 Or SecurityProtocolType.Tls

[Lukager1]

i moved it

Request.Method = "GET"
Request.KeepAlive = True
ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 Or SecurityProtocolType.Tls12 Or SecurityProtocolType.Tls11 Or SecurityProtocolType.Tls
Request.ContentType = "application/json"


and i have the error :
Message=Remote server error: (404) Not found.
is it correct that i have all the path in the variable _command ?
or i must set the server in another place and there just the final path (/files/list_folder) ?

[dday9]

The only other thing I can think of is that you're not including any kind of path parameter in your request. The other parameters appear to either be optional or have default values.

Actually, come to think of it, you should be sending a POST command instead of a GET as well. Try changing the method first, if that doesn't work on its own then also try adding a payload with a "path" property and value:

Private Function DropBoxListFolder()
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 Or SecurityProtocolType.Tls12 Or SecurityProtocolType.Tls11 Or SecurityProtocolType.Tls

    Dim url = "https://api.dropboxapi.com/2/files/list_folder"
    Dim token = "..."

    Dim request = CType(WebRequest.Create(url), HttpWebRequest)
    request.Method = "POST"
    request.Headers.Add("Authorization", $"Bearer {token}")
    request.ContentType = "application/json"

    Dim payloadLiteral = "{
        ""path"": ""-change me-""
    }"

    Dim payload = Encoding.UTF8.GetBytes(payloadLiteral)
    request.ContentLength = payload.Length

    Using dataStream = request.GetRequestStream()
        dataStream.Write(payload, 0, payload.Length)
    End Using

    Try
        Using response = CType(request.GetResponse(), HttpWebResponse)
            Using reader = New StreamReader(response.GetResponseStream())
                Return reader.ReadToEnd()
            End Using
        End Using
    Catch ex As WebException
        Using response = CType(ex.Response, HttpWebResponse)
            Using reader = New StreamReader(response.GetResponseStream())
                Throw New Exception(reader.ReadToEnd())
            End Using
        End Using
	Catch ex As Exception
		Throw
    End Try
End Sub

[Lukager1]

changing just the POST i have an error 401 not authorized

If i try to change the code with yours it's the same.
I try with
Dim payloadLiteral = "{""path"": ""https://www.dropboxapi.com""}"

or
Dim payloadLiteral = "{""path"": ""https://api.dropboxapi.com""}"

and the error it is the some

[dday9]

401 typically means that your authentication is not setup properly, you need to double-check that.

Regarding your path, you should not be setting it to DropBox rather the path you want to search (if applicable).