Botframework-sdk: MS Teams attachments fail for Bots.

[nodeomega]

Are you sending attachments to the bot within a group channel, or one-on-one?

[andyroz]

hi @nodeomega . This is a one-on-one conversation with the bot.

[nodeomega]

I've recently tested using the Windows desktop version (which now includes a paperclip icon for attaching files in one-on-one bot chats from what I'm seeing), and I tried on the iOS version (though in one-on-one I was only able to send a GIF or an image, not any other type). I do not have access to an Android device in order to test on that at this moment.

I was able to access the files through the URLs given (although I had to copy and paste the entire URL, as the hyperlink broke at the first space in the given URL in my case), so perhaps there was a recent change in at least the Windows desktop version. In my case, the text file I uploaded was also directed to a sharepoint URL, not the other type of URL you had referenced. Perhaps there is an environmental variance I am not familiar with. The file I uploaded from the desktop version was retrievable from the iOS version. Again, I am not certain if this was a recent change in functionality.

For the iOS version, the shared GIF files do seem to have clickable or tappable URL's (at least in the way I shared it to my test bot chat). They did show as having a type of "image/*", however. But... when I uploaded an image from my iPhone I was testing with, I did replicate the URL that returned a 401 error when followed.

Based on the linked issue, I believe this to be a limitation more with Teams than with Botbuilder. As I am not aware of any resolution to this issue, and given the age of the issue, I am closing this issue at this time. If there are any other questions, don't hesitate to open a new issue!

[DigitalSa1nt]

It's worth noting that there is no adequate documentation on how to consume In-Line images in Teams or Skype, a content url like:

https://smba.trafficmanager.net/emea/v3/attachments/{Id}]/views/original

Is provided, but throws an authentication error when trying to access it. Does anyone here know the process to access this image?

[EricDahlvang]

Hi @DigitalSa1nt

The request for the file should have an Authentication Header with Bearer token. Here is a C# example:

var attachment = turnContext.Activity.Attachments.First();
using (HttpClient httpClient = new HttpClient())
{
    // Skype & MS Teams attachment URLs are secured by a JwtToken, so we need to pass the token from our bot.
    if (turnContext.Activity.ChannelId.Equals("skype", StringComparison.InvariantCultureIgnoreCase) || turnContext.Activity.ChannelId.Equals("msteams", StringComparison.InvariantCultureIgnoreCase))
    {
        var token = await new MicrosoftAppCredentials().GetTokenAsync();
        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
    }

    var responseMessage = await httpClient.GetAsync(attachment.ContentUrl);
    var contentLenghtBytes = responseMessage.Content.Headers.ContentLength;
    await turnContext.SendActivityAsync($"Attachment of {attachment.ContentType} type and size of {contentLenghtBytes} bytes received.");
}

[DigitalSa1nt]

Hi @DigitalSa1nt

The request for the file should have an Authentication Header with Bearer token. Here is a C# example:

var attachment = turnContext.Activity.Attachments.First();
using (HttpClient httpClient = new HttpClient())
{
    // Skype & MS Teams attachment URLs are secured by a JwtToken, so we need to pass the token from our bot.
    if (turnContext.Activity.ChannelId.Equals("skype", StringComparison.InvariantCultureIgnoreCase) || turnContext.Activity.ChannelId.Equals("msteams", StringComparison.InvariantCultureIgnoreCase))
    {
        var token = await new MicrosoftAppCredentials().GetTokenAsync();
        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
    }

    var responseMessage = await httpClient.GetAsync(attachment.ContentUrl);
    var contentLenghtBytes = responseMessage.Content.Headers.ContentLength;
    await turnContext.SendActivityAsync($"Attachment of {attachment.ContentType} type and size of {contentLenghtBytes} bytes received.");
}

Thank you this was exactly what I was after. Out of interest was there documentation out there about this do you know? Because I couldn't find it.