SSErrorDomain error code 109. NewsStand download from Amazon S3 - ios

Question

While downloading a file from Amazon S3 in iOS. Intermittently NSURLConnectionDownloadDelegate's method didFailWithError: get called and this is what I got when I logged received NSError object
Error Code: 109
Error Domain: SSErrorDomain
Error Description: "Cannot connect to .s3.amazonaws.com"
Searched all the Apple documentation, StackOverflow and other sites but not found anything on this. Today I raised a technical query to Apple also for this using my developer account.
Any idea ?
Update:
So after looking into HTTP response error code (403 Forbidden), I got the idea. It is because of "RequestTimeTooSkewed" error from S3 (The difference between the request time and the current time is too large.). I cross checked it by changing iPad's/Mac's system time by 1 hour and this error is coming immediately now, even for a small (200kb) file.
Now as suggested in many blogs I am first making a HEAD request to AWS as below to get the Date string and not passing the system Date
NSString *awsURL = #"http://s3.amazonaws.com";
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:awsURL]];
[request setHTTPMethod:#"HEAD"];
NSHTTPURLResponse *response;
[NSURLConnection sendSynchronousRequest:request returningResponse:&response error: NULL];
NSString *dateString = nil;
if ([response respondsToSelector:#selector(allHeaderFields)]) {
dateString = [[response allHeaderFields] objectForKey:#"Date"];
}
return dateString;
and setting this as Date header in NSMutableURLRequest
[urlRequest setValue:awsDateString forHTTPHeaderField:#"Date"];
This request I am adding to my issue for download
NKAssetDownload *nkAssetDownload = [nkIssue addAssetWithRequest:urlRequest];
Still the same error !!!! It now more crazier than my last situation.
Anyone ?
Update 2
I was able to make request successfully (even the system clock of my iPad is incorrect) by replacing "GMT" with "+0000" in the date string.
Update 3
Still some requests fail with same error which is weird, but I am assuming it is something the NewsStand Framework is messing up.

Answer 1

So it is RequestTimeTooSkewed error and the above code to fetch date from S3 server's head response to add in request does the trick.