遇到Obj-C 存取 self sign ssl 時會顯示 error:

NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL, -9813)

解法：

For me your first example is working fine. I have tested with the following code without problems (it is of course very insecure since it allows any server certificate).

@implementation
 
 SessionTest

- (void) startSession
{
    NSURL *url = [NSURL URLWithString:@"https://self-signed.server.url"];

    NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration defaultSessionConfiguration];
    NSURLSession *defaultSession = [NSURLSession sessionWithConfiguration
 
: defaultConfigObject delegate: self delegateQueue: [NSOperationQueue mainQueue]];

    NSURLSessionDataTask * dataTask = [defaultSession dataTaskWithURL:url
                                                completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                                                    if
 
(error == nil)
                                                    {
                                                        NSString * text = [[NSString alloc] initWithData: data encoding: NSUTF8StringEncoding];
                                                        NSLog(@"Data: %@",text);
                                                    }
                                                    else
                                                    {
                                                        NSLog(@"Error: %@", error);
                                                    }
                                                }];

    [dataTask resume];
}

- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *credential))completionHandler
{
    completionHandler(NSURLSessionAuthChallengeUseCredential, [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust]);
}

@end

Update: This is the class interface, the SessionTest class is the NSURLSessionDataDelegate, to start the data download you create a SessionTest object and call the startSession method.

@interface SessionTest : NSObject <NSURLSessionDelegate>

- (void) startSession;

@end

或這個範例：

NSURLSessionConfiguration *sessionConfiguration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfiguration delegate:self delegateQueue:Nil];
...
...
- (void)URLSession:(NSURLSession *)session didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential *))completionHandler{
  if([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]){
    if([challenge.protectionSpace.host isEqualToString:@"mydomain.com"]){
      NSURLCredential *credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];
      completionHandler(NSURLSessionAuthChallengeUseCredential,credential);
    }
  }
}