为什么OpenSSL给我一个"你不应该调用的函数"错误？

Question

我正在努力为我的服务器程序添加OpenSSL支持,并且通常它工作得很好,但我遇到了一个问题.

首先,一些背景知识:服务器是单线程的,使用非阻塞I/O和select()循环来同时处理多个客户端.服务器链接到libssl.0.9.8.dylib和lib crypto.0.9.8.dylib(即MacOS/X 10.8.5在/ usr/lib中提供的库).客户端< - >服务器协议是专有的全双工消息传递协议; 也就是说,客户端和服务器都可以随时发送和接收数据,并且客户端< - >服务器TCP连接无限期地保持连接(即直到客户端或服务器决定断开连接).

问题是:我的客户端可以连接到服务器,发送和接收数据工作正常(现在我已经整理了SSL_ERROR_WANT_WRITE和SSL_ERROR_WANT_READ逻辑)...但是如果服务器接受()'是新客户端连接而其他客户端在发送或接收数据的过程中,SSL层似乎破裂了.特别是,在服务器运行SetupSSL()例程(如下所示)以设置新接受的套接字之后,在一个或多个其他(预先存在的)客户端套接字上的SSL_read()将立即返回-1,并且ERR_print_errors_fp(stderr)给出了这个输出:

SSL_read() ERROR:  5673:error:140F3042:SSL routines:SSL_UNDEFINED_CONST_FUNCTION:called a function you should not call:/SourceCache/OpenSSL098/OpenSSL098-47.2/src/ssl/ssl_lib.c:2248:

首次出现此错误后,服务器很大程度上停止工作.数据移动停止,如果我尝试连接另一个客户端,我经常会收到此错误:

SSL_read() ERROR: 5673:error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol:/SourceCache/OpenSSL098/OpenSSL098-47.2/src/ssl/s23_srvr.c:578: 

在我的测试场景中,这种情况大约占25%.如果我确保在新客户端连接时我的预先存在的客户端连接是空闲的(没有数据被发送或接收),它永远不会发生.有谁知道这里可能出了什么问题？我找到了一个OpenSSL错误,还是有一些我忽略的细节？我的程序中的一些相关代码粘贴在下面,以防它有用.

// Socket setup routine, called when the server accepts a new TCP socket
int SSLSession :: SetupSSL(int sockfd)
{
  _ctx = SSL_CTX_new(SSLv23_method());
  if (_ctx)
  {
     SSL_CTX_set_mode(_ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);

     _ssl = SSL_new(_ctx);
     if (_ssl)
     {
        _sbio = BIO_new_socket(sockfd, BIO_NOCLOSE);
        if (_sbio)
        {
           SSL_set_bio(_ssl, _sbio, _sbio);
           SSL_set_accept_state(_ssl);

           BIO_set_nbio(_sbio, !blocking);
           ERR_print_errors_fp(stderr);

           return RESULT_SUCCESS;
        }
        else fprintf(stderr, "SSLSession:  BIO_new_socket() failed!\n");
     }
     else fprintf(stderr, "SSLSession:  SSL_new() failed!\n");
  }
  else fprintf(stderr, "SSLSession:  SSL_CTX_new() failed!\n");

  return RESULT_FAILURE;
}

// Socket read routine -- returns number of bytes read from SSL-land
int32 SSLSession :: Read(void *buffer, uint32 size)
{
  if (_ssl == NULL) return -1;

  int32 bytes = SSL_read(_ssl, buffer, size);
  if (bytes > 0) 
  {
     _sslState &= ~(SSL_STATE_READ_WANTS_READABLE_SOCKET | SSL_STATE_READ_WANTS_WRITEABLE_SOCKET);
  }
  else if (bytes == 0) return -1;  // connection was terminated
  else
  {
     int err = SSL_get_error(_ssl, bytes);
     if (err == SSL_ERROR_WANT_WRITE)
     {
        // We have to wait until our socket is writeable, and then repeat our SSL_read() call.
        _sslState &= ~SSL_STATE_READ_WANTS_READABLE_SOCKET;
        _sslState |=  SSL_STATE_READ_WANTS_WRITEABLE_SOCKET;
        bytes = 0;
     }
     else if (err == SSL_ERROR_WANT_READ)
     {
        // We have to wait until our socket is readable, and then repeat our SSL_read() call.
        _sslState |=  SSL_STATE_READ_WANTS_READABLE_SOCKET;
        _sslState &= ~SSL_STATE_READ_WANTS_WRITEABLE_SOCKET;
        bytes = 0;
     }
     else
     {
        fprintf(stderr, "SSL_read() ERROR:  ");
        ERR_print_errors_fp(stderr);
     }
  }
  return bytes;
}

// Socket write routine -- returns number of bytes written to SSL-land
int32 SSLSession :: Write(const void *buffer, uint32 size)
{
  if (_ssl == NULL) return -1;

  int32 bytes = SSL_write(_ssl, buffer, size);
  if (bytes > 0) 
  {
     _sslState &= ~(SSL_STATE_WRITE_WANTS_READABLE_SOCKET | SSL_STATE_WRITE_WANTS_WRITEABLE_SOCKET);
  }
  else if (bytes == 0) return -1;  // connection was terminated
  else
  {
     int err = SSL_get_error(_ssl, bytes);
     if (err == SSL_ERROR_WANT_READ)
     {
        // We have to wait until our socket is readable, and then repeat our SSL_write() call.
        _sslState |=  SSL_STATE_WRITE_WANTS_READABLE_SOCKET;
        _sslState &= ~SSL_STATE_WRITE_WANTS_WRITEABLE_SOCKET;
        bytes = 0;
     }
     else if (err == SSL_ERROR_WANT_WRITE)
     {
        // We have to wait until our socket is writeable, and then repeat our SSL_write() call.
        _sslState &= ~SSL_STATE_WRITE_WANTS_READABLE_SOCKET;
        _sslState |=  SSL_STATE_WRITE_WANTS_WRITEABLE_SOCKET;
        bytes = 0;
     }
     else
     {
        fprintf(stderr,"SSL_write() ERROR!");
        ERR_print_errors_fp(stderr);
     }
  }
  return bytes;
}

Answer 1

openssl-users邮件列表上的某个人帮我解决了这个问题.问题是,我设置了SSLv23_method(我的SSL会话),并使用SSLv23_method()的时候,你一定不能调用SSL_pending(),直到SSL握手结束后谈判的协议(的SSLv2,SSLv3的,使用TLSv1等)它实际上会用到.

由于我的应用程序并不需要与旧版本SSL的兼容性,快速的工作,各地对我来说是设置的,而不是SSLv23_method期间调用SSLv3_method()().如果需要向后兼容,那么我需要弄清楚的时候协议协商已完成检测某种方式和避免调用SSL_pending()直到那时; 但我会忽略这个问题,现在因为我不需要该功能.