In a previous post I showed how to retrieve your bugs, comments and attachments from YouTrack. However, actually downloading each attachment is a little more work. Assume that the variable Url contains a value like "https://xxxxx.myjetbrains.com/youtrack/_persistent/yyyyy.doc?file=xx-xxx&v=0&c=false"

The following raises a HTTP NotFound exception:

var foo = Connection.Get(Url); //YouTrackSharp.Infrastructure.Connection

As does this:

String basePath = new System.Uri(Url).PathAndQuery;
var foo = Connection.Get(basePath );

The following will raise a HTTP NotAuthorized exception because we are not supplying the authentication cookie to the web-server.

byte[] file = new System.Net.WebClient().DownloadData(Url);

I looked at the YouTrackSharp.Infrastructure.Connection class and I didn’t see anything that would let me retrieve the authentication cookie.

Instead of writing code to manually implement the YouTrack REST API, I decided to take a different approach. I decided to modify YouTrackSharp itself to give me access to the authentication cookie.
I removed the NuGet package YouTrackSharp from my solution.
I downloaded the source of YouTrackSharp from GitHub and unzipped it next to my own project.
I included src\YouTrackSharp\YouTrackSharp.csproj into my solution
I modified src\YouTrackSharp\Infrastructure to add the public modifier as follows:

public CookieCollection _authenticationCookie;

I changed my own program to download the file as follows:

HttpWebRequest req = (HttpWebRequest)WebRequest.Create(Url);
req.CookieContainer = new CookieContainer();
req.CookieContainer.Add(Connection._authenticationCookie);
req.Method = "GET";
WebResponse response = req.GetResponse();
System.IO.Stream Stream = response.GetResponseStream();
var fileStream = System.IO.File.Create(String.Format("C:\\tmp\\{0}", Name));
Stream.CopyTo(fileStream);
fileStream.Close();