MPMoviePlayerController and Auth-Based HLS Backend Server - ios

Question

I am currently serving videos in my iOS application with MPMoviePlayerController. The files are streamed from our backend server that requires authentication. It is key-based authenticated set in the Authorization HTTP Header.
It used to work perfectly with single video files. Now we’re trying to implement HLS adaptive streaming and we have faced a wall. I am currently using a custom NSURLProtocol subclass to catch requests made to our backend server and inject the proper Authorization header. For HLS it simply doesn’t work.
When we looked at the server logs, we clearly saw that the first request to the m3u8 file worked fine. Then all subsequent calls made (other m3u8 files and ts also) are 403 forbidden. It seems that MPMoviePlayerController doesn’t use NSURLProtocol for the other files. (side note: It does work on the simulator thought, but not on a physical device which let me think that both are not implemented in the same way).
MPMoviePlayerController instantiation
self.videoController = [[MPMoviePlayerController alloc] initWithContentURL:video.videoURL];
The URL Protocol interception
+ (NSURLRequest *) canonicalRequestForRequest:(NSURLRequest *)request {
NSMutableURLRequest *newRequest = request.mutableCopy;
[newRequest setValue:#"HIDDEN" forHTTPHeaderField:#"Authorization"];
return newRequest;
}
Any Ideas, suggestions, work arounds?

Answer 1

After verification with Apple Developer Technical Support, I figured what I wanted to achieve is impossible (and unsupported).
Here's the quote from the reply :
The problem you're seeing with NSURLProtocol and so on is that the movie playback subsystem does not run its HTTP requests within your process. Rather, these requests are run from within a separate system process, mediaserverd. Thus, all your efforts to affect the behaviour of that playback are futile.

Answer 2

By using NSURLProtocol, you can intercept the communication between MPMoviePlayerController and the streamed requests. To inject cookies along the way, or possibly save the stream offline videos. To do this, you should to create a new class extending NSURLProtocol:
Hope this helps you:
GAURLProtocol.h
#import <Foundation/Foundation.h>
#interface GAURLProtocol : NSURLProtocol
+ (void) register;
+ (void) injectURL:(NSString*) urlString cookie:(NSString*)cookie;
#end
GAURLProtocol.m
#import "GAURLProtocol.h"
#interface GAURLProtocol() <NSURLConnectionDelegate> {
NSMutableURLRequest* myRequest;
NSURLConnection * connection;
}
#end
static NSString* injectedURL = nil;
static NSString* myCookie = nil;
#implementation GAURLProtocol
+ (void) register
{
[NSURLProtocol registerClass:[self class]];
}
// public static function to call when injecting a cookie
+ (void) injectURL:(NSString*) urlString cookie:(NSString*)cookie
{
injectedURL = urlString;
myCookie = cookie;
}
+ (BOOL)canInitWithRequest:(NSURLRequest *)request {
if([[[request allHTTPHeaderFields] objectForKey:#"Heeehey"] isEqualToString:#"Huuu"])
{
return NO;
}
return [[[request URL] absoluteString] isEqualToString:injectedURL];
}
+ (NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request {
return request;
}
// intercept the request and handle it yourself
- (id)initWithRequest:(NSURLRequest *)request cachedResponse:(NSCachedURLResponse *)cachedResponse client:(id<NSURLProtocolClient>)client {
if (self = [super initWithRequest:request cachedResponse:cachedResponse client:client]) {
myRequest = request.mutableCopy;
[myRequest setValue:#"Huuu" forHTTPHeaderField:#"Heeehey"]; // add your own signature to the request
}
return self;
}
// load the request
- (void)startLoading {
// inject your cookie
[myRequest setValue:myCookie forHTTPHeaderField:#"Cookie"];
connection = [[NSURLConnection alloc] initWithRequest:myRequest delegate:self];
}
// overload didReceive data
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[[self client] URLProtocol:self didLoadData:data];
}
// overload didReceiveResponse
- (void)connection:(NSURLConnection*)connection didReceiveResponse:(NSURLResponse *)response {
[[self client] URLProtocol:self didReceiveResponse:response cacheStoragePolicy:[myRequest cachePolicy]];
}
// overload didFinishLoading
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[[self client] URLProtocolDidFinishLoading:self];
}
// overload didFail
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
[[self client] URLProtocol:self didFailWithError:error];
}
// handle load cancelation
- (void)stopLoading {
[connection cancel];
}
#end
Register
// register protocol
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[NSURLProtocol registerClass:[GAURLProtocol class]];
return YES;
}
Usage
[GAURLProtocol injectURL:#"http://example.com/video.mp4" cookie:#"cookie=f23r3121"];
MPMoviePlayerController * moviePlayer = [[MPMoviePlayerController alloc]initWithContentURL:#"http://example.com/video.mp4"];
[moviePlayer play];

Answer 3

#Marc-Alexandre Bérubé I can think of below workaround:
Run a proxy server in your app to proxy all the video URL's. Download all the video content by injecting the necessary auth headers to the request and relay back the content via the proxy server to the media player to render it. This approach may not work for large videos as the video rendering would only start after entire video is downloaded.