gistfile1.m

- (id) parseReceiptData:(NSData *)receipt_data OnAppStoreUsingURL:(NSURL *) store_URL {

    NSDictionary * request_contents = @{
        @"receipt-data" : [receipt_data base64EncodedStringWithOptions:0]
    };
    
    NSError * error = nil;
    
    NSData * request_data = (
        [NSJSONSerialization
            dataWithJSONObject: request_contents
            options           : 0
            error             : &error
        ]
    );
    NSAssert(error == nil, @"JSON Serialization Error : %@", error);

    NSMutableURLRequest * store_request = [NSMutableURLRequest requestWithURL:store_URL];

    [store_request setHTTPMethod:@"POST"];
    [store_request setHTTPBody:request_data];
    
    NSURLResponse * response;

    NSData * result = (
        [NSURLConnection
            sendSynchronousRequest: store_request
            returningResponse     : &response
            error                 : &error
        ]
    );
    NSAssert(error == nil, @"NSURLConnection Error : %@", error);

    NSDictionary * json_response;
    
    if( result ) {
        json_response =  (
            [NSJSONSerialization
                JSONObjectWithData: result
                options           : 0
                error             : &error
            ]
        );
        NSAssert(error == nil, @"JSON Serialization Error : %@", error);
    }
    return json_response;
}


- (NSDictionary *) parseReceiptOnAppStore {
    
    NSURL   * receipt_url   = [[NSBundle mainBundle] appStoreReceiptURL];
    NSData  * receipt_data  = [NSData   dataWithContentsOfURL:receipt_url];
    
    NSURL   * sandbox_url    = [NSURL URLWithString:@"https://sandbox.itunes.apple.com/verifyReceipt"];
    NSURL   * production_url = [NSURL URLWithString:@"https://buy.itunes.apple.com/verifyReceipt"];
    
    NSDictionary * response;
    
    response = (
        [self
            parseReceiptData  : receipt_data
            OnAppStoreUsingURL: production_url
        ]
    );

    // https://developer.apple.com/library/ios/technotes/tn2259/_index.html#//apple_ref/doc/uid/DTS40009578-CH1-FREQUENTLY_ASKED_QUESTIONS
    // The magic number 21007 means we hit up the production app store servers
    // from the sandbox, viz we are in testing and should switch to the sandbox
    // server thusly ...
    
    if( [response[@"status"] intValue] == 21007  ) {
        
        response = (
            [self
                parseReceiptData  : receipt_data
                OnAppStoreUsingURL: sandbox_url
            ]
        );
    }
    return response;
}