Support BIO read/write retries in OpenSSL 3.3 (#6648)

Co-authored-by: Amaury Chamayou <[email protected]>

Author: maxtropets

src/enclave/tls_session.h

@@ -648,6 +648,10 @@ namespace ccf
         // WANTS_WRITE
         if (put == TLS_WRITING)
         {
+#if defined(OPENSSL_VERSION_MAJOR) && OPENSSL_VERSION_MAJOR >= 3 && \
+  defined(OPENSSL_VERSION_MINOR) && OPENSSL_VERSION_MINOR >= 3
+          BIO_set_retry_write(b);
+#endif
           LOG_TRACE_FMT("TLS Session::send_cb() : WANTS_WRITE");
           *processed = 0;
           return -1;
@@ -697,6 +701,10 @@ namespace ccf
         // WANTS_READ
         if (got == TLS_READING)
         {
+#if defined(OPENSSL_VERSION_MAJOR) && OPENSSL_VERSION_MAJOR >= 3 && \
+  defined(OPENSSL_VERSION_MINOR) && OPENSSL_VERSION_MINOR >= 3
+          BIO_set_retry_read(b);
+#endif
           LOG_TRACE_FMT("TLS Session::recv_cb() : WANTS_READ");
           *processed = 0;
           return -1;