didReceiveAuthenticationChallenge造成EXC_BAD_ACCESS

Question

如果网站不需要身份验证，我的代码工作正常，如果是这样，它的错误与EXC_BAD_ACCESS打印“证书创建”之后。我没有任何释放，而这种代码是从文件复制直 - 任何想法有什么错

- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
 if ([challenge previousFailureCount] == 0)
 {
  NSLog(@"received authentication challenge");

  NSURLCredential *newCredential;
  newCredential=[NSURLCredential credentialWithUser:@"root"
             password:@"rootpassword"
             persistence:NSURLCredentialPersistenceForSession];


  NSLog(@"credential created");

  [[challenge sender] useCredential:newCredential forAuthenticationChallenge:challenge];

  NSLog(@"responded to authentication challenge");

 }
 else
 {
  NSLog(@"previous authentication failure");

  UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Authentication Failure" 
              message:@"Website did not accept the username and password."
                delegate:nil
             cancelButtonTitle:@"OK" 
             otherButtonTitles:nil];
  [alert show];
  [alert release];
 }
}

Answer 1

原来它的是与该特定网站的身份验证方法 - 更换网站，我想登录到另一个网站和代码工作正常

（我是从unRaid的状态页面试图抽取数据，unRaid不使用实际的Web服务器，但emhttp所以我假设有什么关系呢）

Answer 2

你不控制的唯一的事情是[challenge sender]的返回值。尝试打印它的描述，以确保它的非空。