possible crash in ssl stream initialization

[anonymous]

boost::asio::ssl::detail::openssl_stream_service::create may pass a null pointer to SSL_set_mode when SSL_new indicates failure by returning a null pointer. This leads to segmentation faults on the platforms I tested.

Similar issues may hold for boost::asio::ssl::detail::openssl_context_service::create, but I could not yet reproduce this.

[chris_kohlhoff]

(In [79519]) Throw exception if SSL engine initialisation fails. Refs #6303

[chris_kohlhoff]

(In [79549]) Merge from trunk:

• Make strand destruction a no-op, to allow strand objects to be destroyed after their associated io_service has been destroyed.

• Use the thread keyword extension when compiling with gcc on linux x86.

• Avoid calling work_finished() if a completion handler creates more work.

• Eliminate redundant call to call_stack::contains(this) when dispatching a completion handler.

• Add support for some newer versions of glibc which provide the epoll_create1 function but always fail with ENOSYS. Fixes #7012

• Use SSE2 load and store fences.

• Throw exception if SSL engine initialisation fails. Fixes #6303

• Fix another regression in buffered_write_stream. Fixes #6310