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</o:shapelayout></xml><![endif]--></head><body lang=DE link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hello,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>I'm pretty new to OpenSSL and need to implement a secure connection. It's a Win32 application that uses a standard socket implementation up to now and runs for some years already. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>To implement SSL/TLS I downloaded 1.1 and compiled the DLLs for VS2015. The tests are all "green".<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Now I started to integrate OpenSSL into the application. First step for me is to replace the socket implementation with BIO, no security stuff is involved yet. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>The app can be configured to act as a TCP server or a client. I was able to get it to work via BIO as a client, but the problem is the server role. I don't get a valid (second) accept call, no client is able to connect. Inside the app this is done via a non-blocking listening socket (return value is always -1 with "WOULDBLOCK" set), but I even copied the sample code from the blog (blocking mode) into the app’s initialization code and the second call to BIO_do_accept never returns:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> SSL_load_error_strings();<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> ERR_load_BIO_strings();<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> OpenSSL_add_all_algorithms();<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> BIO *abio, *cbio, *cbio2;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> /* First call to BIO_accept() sets up accept BIO */<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> abio = BIO_new_accept("4444");<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> if (BIO_do_accept(abio) <= 0) {<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> fprintf(stderr, "Error setting up accept\n");<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> </span>ERR_print_errors_fp(stderr);<o:p></o:p></p><p class=MsoNormal> <span lang=EN-US>exit(1);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> }<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> <b> /* Wait for incoming connection */<o:p></o:p></b></span></p><p class=MsoNormal><span lang=EN-US> <b> if (BIO_do_accept(abio) <= 0) {<o:p></o:p></b></span></p><p class=MsoNormal><span lang=EN-US> fprintf(stderr, "Error accepting connection\n");<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> </span>ERR_print_errors_fp(stderr);<o:p></o:p></p><p class=MsoNormal> <span lang=EN-US>exit(1);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> }<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> fprintf(stderr, "Connection 1 established\n");<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> /* Retrieve BIO for connection */<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> cbio = BIO_pop(abio);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> ...<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>What's the problem here? I'm currently running under Win 8.1.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal>Best regards,<o:p></o:p></p><p class=MsoNormal>Karsten<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>