Null Pointer Deference in engine.ipp

[g.gupta@…]

​http://svn.boost.org/svn/boost/trunk/boost/asio/ssl/detail/impl/engine.ipp

In below code, ssl_ is checked to be non NUll (which is already done in costructor), which means it can be NULL, but passed to SSL_get_shutdown without NULL check. If it is passed to this function as NULL, it will crash. As ssl_ is already checked in constructor and there is no NULL check in other functions also, checking to not NULL in 214 is always true and hence can be avoided. Please apply the patch.

212   // SSL v2 doesn't provide a protocol-level shutdown, so an eof on the
213   // underlying transport is passed through.
214   if (ssl_ && ssl_->version == SSL2_VERSION)
215     return ec;
216
217   // Otherwise, the peer should have negotiated a proper shutdown.
218   if ((::SSL_get_shutdown(ssl_) & SSL_RECEIVED_SHUTDOWN) == 0)

[Gaurav Gupta <g.gupta@…>]

Avoid possible NULL Pointer derefference .