HTTP status code = 0 (iPhone) (objective c)

Question

Hello,

I want to ask about the iPhone application objective C problem.

I wrote a program to store the cookies and pass to another URL to retrieve the cookies. However, I found that one of the return status code is 0. The content of the html is empty.

Can any one help me? The following is my code.

// create a new mutable url
 NSMutableURLRequest *request_get2 = [[[NSMutableURLRequest alloc] init] autorelease];
    [request_get2 setURL:[NSURL URLWithString:@"http://www.example.com"]];  
 [request_get2 setHTTPMethod:@"GET"];
 [request_get2 setValue:@"text/html; charset=UTF-8" forHTTPHeaderField:@"Content-Type"];
 [request_get2 setValue:@"http://www.example.com" forHTTPHeaderField:@"Referer"];
 [request_get2 setHTTPShouldHandleCookies:YES];
        // cookiesString is a string, the format is "cookieName=cookieValue;"
 [request_get2 setValue: (NSString *) cookiesString forHTTPHeaderField:@"Cookie"];

 // doGet - response
 NSHTTPURLResponse *response_get2 = nil;
 NSError *error_get2 = nil;
 NSData *responseData_get2 = [NSURLConnection sendSynchronousRequest:request_get2 returningResponse:&response_get2 error:&error_get2];
 NSString *data_get2 = [[NSString alloc]initWithData:responseData_get2 encoding:NSUTF8StringEncoding];


 NSString *responseURL_get2 = [[response_get2 URL] absoluteString];           // null value
 NSString *responseTextEncodingName_get2 = [response_get2 textEncodingName];  // null value
 NSString *responseMIMEType_get2 = [response_get2 MIMEType];                  // null value
 NSUInteger *responseStatusCode_get2 = [response_get2 statusCode]; //[responseStatusCode intValue]; // the status code is 0

Thank you very much

Answer 1

If you get a 0 for a response code, the response response_get2 probably was never initialized, which might point to a problem with the request unrelated to your web server.

You set error_get2, so check its value after the request is placed:

if (!error_get2) {
    NSString *responseURL_get2 = [[response_get2 URL] absoluteString];           // null value
    NSString *responseTextEncodingName_get2 = [response_get2 textEncodingName];  // null value
    NSString *responseMIMEType_get2 = [response_get2 MIMEType];                  // null value
    NSUInteger *responseStatusCode_get2 = [response_get2 statusCode]; //[responseStatusCode intValue]; // the status code is 0
}
else {
    NSLog(@"something went wrong: %@", [error_get2 userInfo]);
}

Answer 2

Thank you for your replay. The following is the error in the console.

something went wrong: {
    NSErrorFailingURLKey = https://www.example.com;
    NSErrorFailingURLStringKey = "https://www.example.com";
    NSLocalizedDescription = "untrusted server certificate";
    NSURLErrorFailingURLPeerTrustErrorKey = <NSCFType: 0x3e930f0>;
    NSUnderlyingError = Error Domain=kCFErrorDomainCFNetwork Code=-1202 UserInfo=0x3e95fb0 "The certificate for this server is invalid. You might be connecting to a server that is pretending to be “example.com” which could put your confidential information at risk.";
}

The error is about the cref of the 'HTTPS' certification.

As I have to connect to a server which will pass a certification to me, I must receive the certificate. Can you help me?

Thank you very much.

Answer 3

Hi, Alex, sorry to find you again, but I really cannot solve the problems. I read different post form the Internet. One of the useful is this one (similar answer).

I add the following function in my .m class (I don't know it is correct or not). The following is the content.

- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace {
    NSLog(@"\nused to call the canAuthenticateAgainstProtectionSpace\n");
    return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}

- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {

    NSLog(@"\nused to call the didReveiceAutheticationChallenge\n");
    //if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust])
        //if ([trustedHosts containsObject:challenge.protectionSpace.host])
            [challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];

    [challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];


}

And I add the new statement in the function.

// request in here ... same on the above

NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:request_get2 delegate:self];

// response in here .. same on the above

however I read the same error from the console and the two NSLog from the message is displayed after the error message.

The following is the message from the console.

2010-07-06 12:48:15.381 ABC[1588:20b] 
something went wrong: {
    NSErrorFailingURLKey = https://www.example.com;
    NSErrorFailingURLStringKey = "https://www.example.com";
    NSLocalizedDescription = "untrusted server certificate";
    NSURLErrorFailingURLPeerTrustErrorKey = <NSCFType: 0x3e93b70>;
    NSUnderlyingError = Error Domain=kCFErrorDomainCFNetwork Code=-1202 UserInfo=0x3e96a50 "The certificate for this server is invalid. You might be connecting to a server that is pretending to be “example.com” which could put your confidential information at risk.";
}

2010-07-06 12:48:15.385 ABC[1588:20b] 
Complete all the code
2010-07-06 12:48:16.669 ABC[1588:20b] 
used to call the canAuthenticateAgainstProtectionSpace
2010-07-06 12:48:16.670 ABC[1588:20b] 
used to call the didReveiceAutheticationChallenge

I already cancel the 2 if statements, but I still get wrong.

Can you help me . Thank you very much.