static string GetMimeType(Microsoft.AspNetCore.Http.HttpContext e, UserContentApp app)
{
//Some apps have mandated mime types. Check if this one has that.
if (app.mandatedMimeType != null)
{
return(app.mandatedMimeType);
}
//Get it from the URL params if we can
//If this is missing, return a generic one
if (!e.Request.Query.ContainsKey("mime_type"))
{
return("application/octet-stream");
}
//Get the ID and look it up in the config file.
return(e.Request.Query["mime_type"]);
}
static Stream DoProcessImage(Microsoft.AspNetCore.Http.HttpContext e, Stream input, UserContentApp app)
{
//Try and open this as an image
Image <Rgba32> img;
try
{
img = Image.Load <Rgba32>(input);
} catch
{
throw new StandardError("Failed to open image for processing.", StandardErrorType.ImageOpenFailed);
}
//If we were instructed to do something special with the image, do so
if (app.upload_type == UserContentAppType.image_png_square512)
{
img.Mutate(x => x.Resize(512, 512));
}
//Save the image as a PNG file, then return the stream
MemoryStream ms = new MemoryStream();
img.SaveAsPng(ms);
ms.Position = 0;
//Close stream
img.Dispose();
input.Close();
return(ms);
}
public static Task OnHttpRequest(Microsoft.AspNetCore.Http.HttpContext e)
{
//If this isn't a post request, stop
if (Program.FindRequestMethod(e) != RequestHttpMethod.post)
{
throw new StandardError("Invalid method for this service.", StandardErrorType.NotFound);
}
//Extract the application ID from the query.
UserContentApp application = GetApplication(e);
//Grab the stream of the uploaded file
var file = e.Request.Form.Files["f"];
if (file == null)
{
throw new StandardError("No file found. Make sure this is submitted as a form with the file under the 'f' name.", StandardErrorType.NoFile);
}
Stream s;
try
{
s = file.OpenReadStream();
} catch
{
throw new StandardError("Could not open stream on file.", StandardErrorType.NoFile);
}
//Check if the length is longer than the maximum allowed.
if (file.Length > Program.config.maximum_upload_size)
{
throw new StandardError($"The file you uploaded was too large. Please keep the length under {Program.config.maximum_upload_size} bytes (this file is {file.Length}).", StandardErrorType.FileTooBig);
}
//Do processing if needed.
Stream outStream = DoProcess(e, s, application);
//It is now time to output this to the disk. Generate an ID
var collec = Program.GetFileEntryCollection();
string id = Program.GenerateRandomString(24);
while (collec.Find(x => x._id == id).Count() != 0)
{
id = Program.GenerateRandomString(24);
}
//Generate a one-time token. This can be used to securely send the server the details, even if this is sent to a web client
string token = Program.GenerateRandomString(32);
while (Program.fileCreationTokens.ContainsKey(token))
{
token = Program.GenerateRandomString(32);
}
//Create entry.
UserContentFileEntry entry = new UserContentFileEntry
{
_id = id,
uploadTime = DateTime.UtcNow.Ticks,
filename = id,
applicationId = application.id,
mimeType = GetMimeType(e, application),
deletionToken = Program.GenerateRandomString(64),
url = "https://user-content.romanport.com/u/" + id
};
//Write file
try
{
using (FileStream fs = new FileStream(Program.config.uploaded_content_path + entry.filename, FileMode.Create))
{
outStream.CopyTo(fs);
}
} catch
{
throw new StandardError("Failed to place file on disk. Try again later.", StandardErrorType.UnknownError);
}
//Insert entry
collec.Insert(entry);
//Insert entry into the temporary tokens directory
Program.fileCreationTokens.Add(token, entry);
//Close the stream
try
{
outStream.Close();
}
catch { }
//Respond
return(Program.QuickWriteJsonToDoc(e, new CreateResponse
{
ok = true,
token = token,
url = entry.url
}));
}
static Stream DoProcess(Microsoft.AspNetCore.Http.HttpContext e, Stream input, UserContentApp app)
{
//If this is a binary upload, just return the same stream
if (app.upload_type == UserContentAppType.binary)
{
return(input);
}
//If this is a type of image, open it and throw an error if it is invalid.
if (app.upload_type == UserContentAppType.image_png || app.upload_type == UserContentAppType.image_png_square512)
{
return(DoProcessImage(e, input, app));
}
//Unknown
throw new StandardError("Unknown application type.", StandardErrorType.UnknownError);
}
