NSURLConnection doesn't call NSURLConnectionDelegate authentication methods after an HTTP 401

Question

I'm consume a web service that uses HTTP basic auth with an NSURLConnection. In my NSURLConnectionDelegate, I implemented –[NSURLConnectionDelegate connection:canAuthenticateAgainstProtectionSpace:], –[NSURLConnectionDelegate connection:didCancelAuthenticationChallenge:], and –[NSURLConnectionDelegate connection:didReceiveAuthenticationChallenge:], but none of them get called.

I've tried implementing –[NSURLConnectionDelegate connectionShouldUseCredentialStorage:] to return both YES and NO, but that had no effect.

I also ensured that my NSURLCredentialStorage was empty.

Finally, instead of implementing –[NSURLConnectionDelegate connection:canAuthenticateAgainstProtectionSpace:], –[NSURLConnectionDelegate connection:didCancelAuthenticationChallenge:], and –[NSURLConnectionDelegate connection:didReceiveAuthenticationChallenge:], I implemented –[NSURLConnectionDelegate connection:willSendRequestForAuthenticationChallenge:], but it wasn't called either.

What can I do to make NSURLConnection call NSURLConnectionDelegate's authentication callbacks?

Answer 1

My HTTP server isn't returning a WWW-Authenticate header.

My server's response:

HTTP/1.1 401 Unauthorized
Date: Wed, 19 Jun 2013 14:43:30 GMT
Server: Apache-Coyote/1.1
Expires: Wed, 19 Jun 2013 14:43:30 GMT
Vary: Accept-Encoding,User-Agent
Cache-Control: no-store, no-cache, must-revalidate, private, max-age=0
Content-Length: 0
Content-Type: text/plain

Another server response with a WWW-Authenticate header:

HTTP/1.1 401 Authorization Required
Date: Wed, 19 Jun 2013 14:44:47 GMT
Server: Apache/2.2.17 (CentOS)
WWW-Authenticate: Basic realm="[LDAP/PROD] Active Directory"
Content-Length: 0
Connection: close
Content-Type: text/plain

It looks like NSURLConnection requires the WWW-Authenticate header in its response for it to call NSURLConnectionDelegate's authentication callbacks.

I've filed a radar about this. Please duplicate it.

Apparently, I'll have to manually set the Authorization header since NSURLConnection will not allow you to proactively authenticate with NSURLCredential.