iOS FairPlay videos not playing after obtaining CKC from server

Question

I am trying to implement FairPlay in my application.

I am able to play an encrypted video using the SDK given by Apple but the problem is the SDK is in Swift but my project is in Objective C.

So i have re-written the code in my project but i am unable to play a video.

Here are the links in am using:

1. Playlist: https://willzhanmswest.streaming.mediaservices.windows.net/92fc0471-0878-4eeb-80a3-e5b6fc497806/NoAudio.ism/manifest(format=m3u8-aapl)

2. Certificate: https://openidconnectweb.azurewebsites.net/Content/FPSAC.cer

Here are the steps i have followed:

1. Added a delegate to the AVURLAsset to call this function shouldWaitForLoadingOfRequestedResource.
2. In this function, i am first getting the contents of certificate in NSData
3. Then, i am obtaining the asset string and converting it to NSData.
4. Then, i am calling this function to create SPC value.

NSData *spc = [loadingRequest streamingContentKeyRequestDataForApp:certificate contentIdentifier:assetId options:nil error:nil];

5. The SPC received and Asset ID is then passed to Azure server with application/x-www-form-urlencoded content-type.
6. The CKC received is then trimmed to remove and tags and then converted it to Base64String and then called these functions

[dataRequest respondWithData:base64CkcData];

[loadingRequest finishLoading];

Can anyone help me find what am i doing wrong here?

Thanks.

Answer 1

I was having similar troubles to this. I'm assuming you'd started with an obj-c version of https://gist.github.com/fousa/5709fb7c84e5b53dbdae508c9cb4fadc, yes? This code portion seems to work for me, and I am just wondering if this is what you had already.

// licenseRequestURL is https://keydeliveryURL.azure.net/FairPlay/?kid=whatever-your-key-id-is
// contentId is keydeliveryURL.azure.net

// Create HTTP request
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:licenseRequestURL];
[request setHTTPMethod:@"POST"];
[request setValue:[NSString stringWithFormat:@"Bearer %@",authenticationToken] forHTTPHeaderField:@"Authorization"];

// Create Request HTTP body:
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
NSString *spcString = [spcData base64EncodedStringWithOptions:0];
NSString *httpBodyString = [NSString stringWithFormat:@"spc=%@&assetId=%@",
                            [spcString stringByAddingPercentEncodingWithAllowedCharacters:
                             [[NSCharacterSet characterSetWithCharactersInString:@"="] invertedSet]], contentId];
[request setHTTPBody:[httpBodyString dataUsingEncoding:NSUTF8StringEncoding]];

// Create session to run request asynchronously
NSURLSession *session = [NSURLSession sessionWithConfiguration:NSURLSessionConfiguration.defaultSessionConfiguration
                                                      delegate:self
                                                 delegateQueue:nil];
NSURLSessionTask *task = [session dataTaskWithRequest:request
completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
    NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) response;

    NSString *dataString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    NSString *stringStrippedOfCkcTags = [[dataString stringByReplacingOccurrencesOfString:@"<ckc>"
                                                                               withString:@""]
                                stringByReplacingOccurrencesOfString:@"</ckc>"
                                                          withString:@""];
    NSData *base64CkcData = [[NSData alloc] initWithBase64EncodedString:stringStrippedOfCkcTags
                                                                options:0];

    [dataRequest respondWithData:base64CkcData];
    [loadingRequest finishLoading];
}];
[task resume];

If this is what you have then perhaps the video is the issue.