NTLM身份验证在iOS应用程序中丢失POST正文

Question

我试图通过标准方式向NTLM身份验证发送请求到网络服务：

- (void)connection:(NSURLConnection *)connection
willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
    if ([challenge previousFailureCount] > 0) {
        [[challenge sender] cancelAuthenticationChallenge:challenge];
    } else {
        NSURLCredential *cred = [NSURLCredential
                                 credentialWithUser:username
                                 password:password
                                 persistence:NSURLCredentialPersistenceForSession];

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

GET请求正常，但POST请求有问题。 NTLM握手过程丢失POST数据。它看起来像这样：

1: iOS  --> Web   POST {body JSON}


2: iOS <--  Web   401 Unauthorized
              WWW-Authenticate: NTLM

3: iOS  --> Web   POST (empty POST request, no body data!)
              Authorization: NTLM <base64-encoded type-1-message>

4: iOS <--  Web   401 Unauthorized
              WWW-Authenticate: NTLM <base64-encoded type-2-message>

5: iOS  --> Web   POST (empty POST request, no body data!)
              Authorization: NTLM <base64-encoded type-3-message>

6: iOS <--  Web   500 Internal Error (it's normal, because body is empty)

Android应用没有问题，它按预期工作。有什么想法吗？