Upload image into asp.net web service in swift - ios

Question

How can I upload an image into my web service then I can save it on my server!
I have tried the below code using POST method but I got this error
(A potentially dangerous Request.Form value was detected from the client (uploadFile="<ffd8ffe0 00104a46 4...").)
func myImageUploadRequest() {
let imageData = UIImageJPEGRepresentation(myImageView, 1)
let boundary = generateBoundaryString()
var base64String = imageData.base64EncodedStringWithOptions(.allZeros)
let myUrl = NSURL(string: "http://xxxxx/UploadImageTest");
let request = NSMutableURLRequest(URL:myUrl!);
request.HTTPMethod = "POST";
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
if(imageData==nil) { return; }
var body = NSMutableData();
body.appendString("uploadFile=\(imageData)")
request.HTTPBody = body
let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
data, response, error in
if error != nil {
println("error=\(error)")
return
}
// You can print out response object
println("******* response = \(response)")
// Print out reponse body
let responseString = NSString(data: data, encoding: NSUTF8StringEncoding)
println("****** response data = \(responseString!)")
dispatch_async(dispatch_get_main_queue(),{
});
}
task.resume()
}
And this the POST SOAP on my Asp.net web service
POST /xxxx.asmx/UploadImageTest HTTP/1.1
Host: xxxx.com
Content-Type: application/x-www-form-urlencoded Content-Length: length
uploadFile=string&uploadFile=string

Answer 1

The error was sending NSData to Asp.net web service.
convert the image int base64 using this code
let imageData = UIImageJPEGRepresentation(myImageView, 1)
var base64String = imageData.base64EncodedStringWithOptions(.allZeros)
then send it to web service and make sure in your web service receive String data, not byte() array.
in your web service convert the base64 into Image and save into your server.
That's it!.

Answer 2

I am not familiar with Swift but in Objective C I would have prepared data something like this:
....
NSMutableString* body = [NSMutableString new];
[body appendFormat:#"uploadFile=%#",base64String];
....
The reason it is erring out is pretty obvious from the error description. You might find your code is formatting your base64 image string as
uploadFile="<ffd8ffe0 00104a46 4...
The text after uploadFile= is not at all a base64 encoded string rather the string representation of NSData and that extra < at the starting of the data is being treated as a html tag in server. ASP.NET request validation does not allow such tags in your request body as security measure, to prevent code/script injection and cross site scripting.
Even if you disable request validation from server web.config or .asmx the data would still not be interpreted by server as it would still not be in valid base64 format as the server might expect.
So my advice is to frame your request properly before sending it to server and everything should work seamlessly.