+dnl -----------------
+dnl Enable TLS?
+dnl -----------------
+dnl By default (with_tls=''), enable TLS if header and libs were found.
+dnl If TLS requested (--with-tls with_tls=yes), error if header/lib not found.
+dnl If TLS disabled (--without-tls with_tls=no), don't enable it.
+tls_support=no
+TLS_SUPPORT=0
+AC_SUBST([TLS_SUPPORT])
+AS_IF([test "x$with_tls" = xyes && test "x$HAVE_SSL_H" = x],
+ [AC_MSG_ERROR([TLS requested but openssl/ssl.h not found])],
+ [test "x$with_tls" = xyes && test "x$TLSLIB" = x],
+ [AC_MSG_ERROR([TLS requested but crypto or ssl library not found])],
+ [test "x$with_tls" != xno && test "x$HAVE_SSL_H" = x1 && test "x$TLSLIB" != x],
+ [AC_DEFINE([TLS_SUPPORT], [1], [Support TLS for session encryption.])
+ TLS_SUPPORT=1
+ tls_support=yes])
+