有一个支持的API来完成这个!在你的NSURLConnection委托中添加如下内容:

- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace {
  return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}

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

注意connection:didReceiveAuthenticationChallenge:可以将其消息发送给challenge。发送方(很久以后)，在必要时向用户呈现对话框之后，等等。

由Nathan de Vries发布的category工作区将通过AppStore私有API检查，并且在你无法控制NSUrlConnection对象的情况下很有用。 一个例子是NSXMLParser，它将打开你提供的URL，但不公开NSURLRequest或NSURLConnection。

在iOS 4中，解决方法似乎仍然有效，但仅在设备上，模拟器不再调用allowsAnyHTTPSCertificateForHost:方法。

如果你想继续使用sendSynchronousRequest，我在这个解决方案:

FailCertificateDelegate *fcd=[[FailCertificateDelegate alloc] init];

NSURLConnection *c=[[NSURLConnection alloc] initWithRequest:request delegate:fcd startImmediately:NO];
[c setDelegateQueue:[[NSOperationQueue alloc] init]];
[c start];    
NSData *d=[fcd getData];

你可以在这里看到:Objective-C SSL同步连接

与AFNetworking我已经成功地消费https webservice与以下代码，

NSString *aStrServerUrl = WS_URL;

// Initialize AFHTTPRequestOperationManager...
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.requestSerializer = [AFJSONRequestSerializer serializer];
manager.responseSerializer = [AFJSONResponseSerializer serializer];

[manager.requestSerializer setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
manager.securityPolicy.allowInvalidCertificates = YES; 
[manager POST:aStrServerUrl parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject)
{
    successBlock(operation, responseObject);

} failure:^(AFHTTPRequestOperation *operation, NSError *error)
{
    errorBlock(operation, error);
}];

您可以使用此代码

-(void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
     if ([[challenge protectionSpace] authenticationMethod] == NSURLAuthenticationMethodServerTrust)
     {
         [[challenge sender] useCredential:[NSURLCredential credentialForTrust:[[challenge protectionSpace] serverTrust]] forAuthenticationChallenge:challenge];
     }
}

使用-connection:willSendRequestForAuthenticationChallenge:代替这些已弃用的方法

弃用:

-(BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace  
-(void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge 
-(void)connection:(NSURLConnection *)connection didCancelAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge

To complement the accepted answer, for much better security, you could add your server certificate or your own root CA certificate to keychain( https://stackoverflow.com/a/9941559/1432048), however doing this alone won't make NSURLConnection authenticate your self-signed server automatically. You still need to add the below code to your NSURLConnection delegate, it's copied from Apple sample code AdvancedURLConnections, and you need to add two files(Credentials.h, Credentials.m) from apple sample code to your projects.

- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace {
return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}

- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
//        if ([trustedHosts containsObject:challenge.protectionSpace.host])

    OSStatus                err;
    NSURLProtectionSpace *  protectionSpace;
    SecTrustRef             trust;
    SecTrustResultType      trustResult;
    BOOL                    trusted;

    protectionSpace = [challenge protectionSpace];
    assert(protectionSpace != nil);

    trust = [protectionSpace serverTrust];
    assert(trust != NULL);
    err = SecTrustEvaluate(trust, &trustResult);
    trusted = (err == noErr) && ((trustResult == kSecTrustResultProceed) || (trustResult == kSecTrustResultUnspecified));

    // If that fails, apply our certificates as anchors and see if that helps.
    //
    // It's perfectly acceptable to apply all of our certificates to the SecTrust
    // object, and let the SecTrust object sort out the mess.  Of course, this assumes
    // that the user trusts all certificates equally in all situations, which is implicit
    // in our user interface; you could provide a more sophisticated user interface
    // to allow the user to trust certain certificates for certain sites and so on).

    if ( ! trusted ) {
        err = SecTrustSetAnchorCertificates(trust, (CFArrayRef) [Credentials sharedCredentials].certificates);
        if (err == noErr) {
            err = SecTrustEvaluate(trust, &trustResult);
        }
        trusted = (err == noErr) && ((trustResult == kSecTrustResultProceed) || (trustResult == kSecTrustResultUnspecified));
    }
    if(trusted)
        [challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
}

[challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];
}