NSURLRequest setValue: forHTTPHeaderField:@“Authorization” not working

Question

I try to make an authenticate call to the twitter API with the Application only Authentication API

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:url] 
                                                       cachePolicy:NSURLRequestReloadIgnoringLocalCacheData 
                                                   timeoutInterval:20.0];
[request setHTTPMethod:@"POST"];
[request setValue:@"application/x-www-form-urlencoded;charset=UTF-8" forHTTPHeaderField:@"Content-Type"];
[request setValue:@"Some App Name" forHTTPHeaderField:@"User-Agent"];
[request setValue:authValue forHTTPHeaderField:@"Authorization"];
[request setHTTPBody:[@"grant_type=client_credentials" dataUsingEncoding:NSUTF8StringEncoding]];

Interestingly the authValue is not getting set for HTTPHeaderField @"Authorization". Therefor my calls fail of course. All other header fields are set correctly.

I check it by

NSLog(@"Authorization, %@, %@", [request valueForHTTPHeaderField:@"Authorization"], authValue);

which returns @"Authorization, (null), theCorrectStuff

Why is this happening? I should be able to set it right away, or am I missing something?

Thanks for your time and consideration, Fabian

Answer 1

I had the same issue. Output your authValue, it probably contains new lines. For the application only authentication after you do base64 you need to remove new lines from authValue otherwise the header field won't be set.

Or just use already written Objective-C library for Twitter REST API 1.1 (https://github.com/nst/STTwitter).