+AS_IF([test "x$with_ssl" = xgnutls], [
+ AC_CHECK_HEADERS([gnutls/gnutls.h], [], [AC_MSG_ERROR([could not find gnutls/gnutls.h])])
+ AC_CHECK_LIB([gnutls], [gnutls_priority_init], [], [AC_MSG_ERROR([could not find libgnutls])])
+ AC_CHECK_LIB([nettle], [_nettle_aes_decrypt], [], [AC_MSG_ERROR([could not find libnettle])])
+ AC_DEFINE([USE_GNUTLS], [], [Use GnuTLS])
+])