iOS似乎繞過了基本的服務器身份驗證

Question

我試圖讓我的iOS應用程序使用基本身份驗證從我的本地apache服務器訪問文件。在瀏覽器中一切正常，我必須輸入我的用戶名和密碼才能訪問受限制文件夾中的圖像。但在應用程序中發生了一些奇怪的事情。

我做了NSURLConnection到服務器（這一切都工作正常），並在我的請求第一次作出代理方法- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge被調用。出於測試目的，我回應一個空的NSURLCredential，顯然連接失敗。但是，當我再次發出請求時，委託方法不會被調用，並且不知何故，圖像會被下載並顯示，而無需任何身份驗證。對於發生了什麼，我感到非常困惑！

下面是一些代碼：

- (IBAction)loginPressed 
{ 
    self.username = self.usernameField.text; 
    self.password = self.passwordField.text; 
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://192.168.0.2/secret/favicon.ico"]]; 
    self.connection = [NSURLConnection connectionWithRequest:request delegate:self]; 
} 


- (void)connection:(NSURLConnection *)theConnection didReceiveData:(NSData *)data 
{ 
    [self.data appendData:data]; 
} 

- (void)connectionDidFinishLoading:(NSURLConnection *)connection 
{ 
    self.imageView.image = [UIImage imageWithData:self.data]; 
    self.errorLabel.text = @""; 
} 

- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge 
{ 
    if ([challenge previousFailureCount] == 0) { 
     NSURLCredential *newCredential = [NSURLCredential credentialWithUser:self.username password:self.password persistence:NSURLCredentialPersistenceNone]; 
     [challenge.sender useCredential:newCredential forAuthenticationChallenge:challenge]; 
    } else { 
     [challenge.sender cancelAuthenticationChallenge:challenge]; 
     self.errorLabel.text = @"Invalid Username and/or Password"; 
     self.imageView.image = [UIImage imageWithData:[[NSData alloc] init]]; 
    } 
} 

Answer 1

您應該使用不同的委託回調，connection:didReceiveAuthenticationChallenge:。

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

    if ([challenge previousFailureCount] > 0) { 
     // Do something, like prompt for credentials or cancel the connection 
    } else { 
     NSURLCredential *creds = [NSURLCredential 
          credentialWithUser:@"someUser" 
            password:@"somePassword" 
           persistence:NSURLCredentialPersistenceForSession]; 

     [[challenge sender] useCredential:creds forAuthenticationChallenge:challenge]; 
    } 
}