Hi, I am trying to write the simplest possible example of an async TLS client and server using non-blocking IO and SSL_ERROR_WANT_READ/SSL_ERROR_WANT_WRITE events. The main purpose is to test the async IO code paths with a). an absence of all of the complex options in s_client and s_server, and b). self-contained source that is easy to read. I am having an issue where the server crashes on subsequent connections *if* I close the connection file descriptor. See the note in openssl_async_echo_server.cc on line 239. If I leak a file descriptor and the next connection uses a new fd then the server works fine. Does openssl have an internal map of file descriptors? Am I freeing the connection correctly? SSL_free(ssl_conn.ssl); // TODO - crashes on subsequent connections in SSL_do_handshake if we close the fd. // ssl_lib.c::SSL_do_handshake::s->method->ssl_renegotiate_check(s); // Why? reuse of same fd number for subsequent connection? // comment the following line and the server works but leaks fds close(ssl_conn.conn_fd); Here is the code: https://github.com/michaeljclark/async_tls_test/blob/master/src/openssl_async_echo_server.cc https://github.com/michaeljclark/async_tls_test/blob/master/src/openssl_async_echo_client.cc Both files are standalone with no dependencies (one of the goals) and can be compiled as so: clang++ -std=c++11 openssl_async_echo_client.cc -lcrypto -lssl -o openssl_async_echo_client clang++ -std=c++11 openssl_async_echo_server.cc -lcrypto -lssl -o openssl_async_echo_server or alternatively they can be built using the Makefile in the git repo which contains all dependencies beside openssl e.g. demo cert.pem, key.pem and cacert.pem: https://github.com/michaeljclark/async_tls_test/ e.g. git clone https://github.com/michaeljclark/async_tls_test.git cd async_tls_test make I would appreciate if anyone could help me out. It may well be a bug in my demo code or it could be a bug in openssl. I've used a smattering of C++1y where it simplifies the code (connection hash table, poll descriptor management) but it is mostly plain C. A simple example of a *working* async openssl client and server would be quite useful... Michael.
