AFNetworking2.0 访问HTTPS服务器

在AFNetworking2.0下想要访问HTTPS服务器，需要做如下设置:

    AFSecurityPolicy *securityPolicy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeNone];
    [securityPolicy setAllowInvalidCertificates:YES];

    NSURL *URL = [NSURL URLWithString:url];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
    AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:request];
    [op setSecurityPolicy:securityPolicy];
    op.responseSerializer = [AFJSONResponseSerializer serializer];
    [op setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
        //Success
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        //Failed
    }];